Patent Publication Number: US-7225171-B2

Title: Air conditioning equipment operation system and air conditioning equipment designing support system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application is a divisional of Ser. No. 10/066,667 filed 6 Feb. 2002 and issued as U.S. Pat. No. 6,591,620 B2. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to an air conditioning equipment operation system for operating air conditioning equipment, and a designing support system for designing and supporting the air conditioning equipment. 
   An example of conventional air conditioning equipment is described in JP-A-8-86533. The air conditioning equipment described in that document is constructed by combining absorption and compression air conditioners. During application of a low load, the absorption air conditioner is first operated. When an air conditioning load exceeds a maximum load of the absorption air conditioner, the absorption and compression air conditioners are both operated. 
   In addition, JP-A-7-139761 describes a system for operating a cooling tower when an outside air temperature detected by outside air temperature detecting means is lower than an indoor temperature detected by indoor temperature detecting means, in order to efficiently use energy in a clean room by using the cooling tower. 
   In the case of the air conditioning equipment described in JP-A-8-86533, an absorption freezer is operated with priority, and then a compression freezer is operated according to a load. However, in the air conditioning equipment described therein, the freezer to be operated is only changed to another according to cooling capability. Sufficient consideration is not always given to reductions in costs for operating each freezer by taking a characteristic thereof into consideration. 
   In the case of the system described in JP-A-7-139761, when the outside air temperature is low, switching is made to the operation of the cooling tower. However, since cooling capability of the cooling tower is greatly dependent on a humidity condition of an outside air, the capability of the cooling tower may not always be used satisfactorily, or cooling by the cooling tower may be impossible. 
   SUMMARY OF THE INVENTION 
   The present invention was made to remove the foregoing inconveniences of the conventional art, and it is an object of the invention is to operate air conditioning equipment by reducing running costs. Another object of the invention is to reduce costs for air conditioning equipment including initial costs. Yet another object of the invention is to provide cold water at low costs. A further object of the invention is to achieve at least one of those objects. 
   In order to achieve the foregoing object, a feature of the invention is that in an air conditioning equipment operation system where a service provider company operates air conditioning equipment installed in a contract site, the service provider company sets full load or partial load running for a turbo freezer and/or an absorption freezer based on annual air conditioning load fluctuation data and/or weather data, in such a way as to minimize the total running costs of the turbo freezer and/or absorption freezer provided in the air conditioning equipment. 
   In this case, the total running costs may include costs of a cooling tower for radiating heat generated in a clean room accommodating a production unit of the air conditioning equipment, and heat generated by the production unit. The service provider company may control the air conditioning equipment of the contract site through a public line or Internet, and obtain the weather data from a weather forecast company through the public line or the Internet. 
   In order to achieve the foregoing object, another feature of the invention is that in an air conditioning equipment operation system where air conditioning equipment provided in a contract site is operated by a service provider company, the service provider company has a control server, which includes a device information database storing a device characteristic data of an air conditioner constituting the air conditioning equipment, a fuel or electricity rate database storing rate data of at least one of gas, oil and electric power, and an air conditioning equipment simulator for obtaining a partial load factor, and at least one selected from consumption of power and consumption of fuel during partial load running by using the device characteristic data and a cycle simulator, and calculating running costs from the obtained consumption of power and/or the obtained consumption of fuel by using the rate data. The contract site includes an air conditioning equipment management controller provided to manage and control the air conditioning equipment. The control server and the air conditioning equipment management controller are connected to each other through a network. The control server predicts a cooling load from predictable time series data on a temperature and humidity of outside air by referring to the device information database, and then makes an operation plan of the air conditioner. The air conditioning equipment management controller operates the air conditioner according to the operation plan. 
   In this case, the air conditioning equipment simulator calculates running costs for each operation of the air conditioner, and makes operation plan data by an operation method having lowest running costs among the calculated running costs; the air conditioning equipment includes absorption and turbo freezers, and the air conditioning equipment simulator selects full or partial loads of the freezers according to a set amount of cooled heat of the absorption and turbo freezers, and calculates running costs in this case; the air conditioning equipment includes a cooling tower, and the air conditioning equipment simulator calculates running costs according to the operation/stop of the cooling tower; an object to be cooled provided in the air conditioning equipment is cooled by cold water generated by a cold water generator of the service provider company, a temperature sensor for detecting a cooled heat amount of this cold water is provided in the vicinity of the object to be cooled, and the air conditioning equipment simulator obtains an amount of heat for colling from a temperature detected by the temperature sensor, and calculates a use rate of the contract site; the control server predicts a cooling load from prediction data on a temperature and humidity of an outside air purchased from a weather forecast company, and the air conditioning equipment simulator sets an operation method of the air conditioning equipment in the air conditioning equipment management controller through a web based on the predicted cooling load; means may be provided for detecting the temperature and humidity of the outside air, means may be provided for detecting a cooling load of the air conditioning equipment, an equation of relation between the cooling load and the temperature and humidity of the outside air may be obtained from the temperature and humidity of the outside air, and the cooling load detected by the detecting means, and a cooling load may be predicted by using this equation of relation. 
   In order to achieve the foregoing object, yet another feature of the invention is that an air conditioning equipment designing support system for supporting designing of a number of air conditioners provided in air conditioning equipment comprises: a step (A) of generating an annular cooling load fluctuation pattern of the air conditioning equipment; a step (B) of calculating initial costs by referring to a device information database storing device characteristics and prices of the number of air conditioners; a step (C) of calculating annual running costs from the annual cooling load fluctuation pattern by referring to the database storing the device characteristics and the prices, and a database storing fuel and electricity rates; a step (D) of calculating costs including device taxes and interest rates; and a step (E) of calculating total costs including the initial costs, and running costs of a set number of years. By changing the configuration of the air conditioners of the air conditioning equipment, and repeating the steps (B) to (E), each air conditioner of the air conditioning equipment is set in such a way as to minimize the total costs. 
   In this case, preferably, an annual cooling load pattern is produced by using a weather information database storing weather data on a past temperature and humidity of an outside air. 
   In order to achieve the foregoing object, a further feature of the invention is that in an air conditioning equipment operation system where air conditioning equipment provided in a contract site is operated by a service provider company, an object to be cooled in the air conditioning equipment is cooled by cold water generated by a cold water generator of the service provider company, a cooled heat amount of this cold water is obtained from outputs of a temperature sensor and a flow meter installed in the vicinity of the object to be cooled, and a use rate is obtained by calculating this obtained cooled heat amount with a predetermined rate. 
   Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram showing an air conditioning equipment operation system according to an embodiment of the present invention. 
       FIG. 2  is a block diagram showing an air conditioning equipment management controller used in the air conditioning equipment operation system of FIG.  1 . 
       FIG. 3  is a system flowchart of air conditioning equipment used the air conditioning equipment operation system of  FIG. 1 . 
       FIG. 4  is a view illustrating running costs of a freezer. 
       FIG. 5  is a view illustrating an operation pattern of the freezer. 
       FIG. 6  is a view illustrating running costs of the freezer. 
       FIG. 7  is a view illustrating a cooling load of a clean room. 
       FIG. 8  is a view illustrating a cooling load of the air conditioning equipment. 
       FIG. 9  is a flowchart for operating the air conditioning equipment. 
       FIG. 10  is a view illustrating a change in the cooling load. 
       FIG. 11  is a view illustrating another change in the cooling load. 
       FIG. 12  is a flowchart for optimizing air conditioner designing. 
       FIG. 13  is a view showing an example of a device configuration data set. 
       FIG. 14  is a view illustrating consumption of power in the air conditioning equipment. 
       FIG. 15  is a view illustrating load fluctuation. 
       FIG. 16  is a view illustrating privity of contract between companies. 
       FIG. 17  is a view illustrating privity of contract between companies. 
       FIG. 18  is a system flowchart of air conditioning equipment according to another embodiment. 
       FIG. 19  is a view illustrating an operation of a cooling tower. 
       FIG. 20  is a view illustrating running costs of the air conditioning equipment. 
       FIG. 21  is a view illustrating an operation of a cooling tower. 
       FIG. 22  is a view illustrating cooling costs. 
   

   DESCRIPTION OF THE EMBODIMENTS 
   Next, description will be made of the embodiments of the present invention with reference to the accompanying drawings.  FIG. 1  shows an entire configuration of an air conditioning equipment operation system according to an embodiment of the invention. In the air conditioning equipment operation system, a service provider company  2  is connected to contract sites  1 ,  1   a  and  1   b  through a network  10 . The service provider company  2  has a control server  20 . Various bits of information stored in the control server  20  are transmitted to/received by an air conditioning equipment management controller  30  of the contract site  1  through the network  10 . In the contract site  1 , an air conditioning equipment communication line  38  is connected to enable data to be transmitted from the air conditioning equipment management controller  30  to each device constituting air conditioning equipment  39  or received from each device. 
   The service provider company  2  has a weather forecast information provision contract with a weather forecast company  8 . Weather forecast data is provided from the weather forecast company  8  to the service provider company  2  through the network  10 . The weather forecast data is prediction data containing a temperature and humidity of an outside air. The service provider company  2  makes an operation plan for the air conditioning equipment  39  of the contact site  1  by using the weather forecast data of the weather forecast company  8 . Based on this operation plan, the air conditioning equipment controller  30  manages and controls the air conditioning equipment  39 . Cold water is supplied from the air conditioning equipment  39  to a contract company  11 , and each room of the contract company  11  is air-conditioned, or a device is cooled. A relation between the contract site  1  and the contract company  11  is set, for example in a manner that the contract company owns a plant or a building, and takes air conditioning equipment including running control on lease or the like from the contract site  1 . Accordingly, the contract site  1  is responsible for entire management of an air conditioner of the contract company  11 . 
   The control server  20  of the service provider company  2  has hardware including communication means  52  for controlling communications through the network  10 , input/output means  51  including a display, a keyboard, a mouse and the like, storage means  54  such as a hard disk, and calculation means  53  such as a microcomputer. The control server  20  also includes a fuel/power rate database  21 , a device information database  24 , a system configuration database  22 , a running record database  25 , a weather information database  23 , operation control means  41 , an air conditioning equipment simulator  42 , device characteristic correction means  43 , operation method optimizing means  44 , and equipment designing support means  45 . 
   The device information database  24  stores characteristic and price data on devices constituting the air conditioning equipment  39  connected to the air conditioning equipment management controller  30 . These data include device characteristic and price data provided from a manufacturing company of each device, and device characteristic data corrected by the device characteristic correction means  43  based on running record data of such a device. The fuel/power rate database  21  stores a gas rate of a gas supply company  4 , a power rate of a power supply company  5 , and an oil sales price of an oil selling company  6  from the past to the present. 
   The weather information database  23  stores weather data including a temperature, humidity and the like. The weather data includes data such as AMEDAS (Automated MEteorological Data Acquisition System) provided by Meterological Agency, and weather forecast data forecast by the weather forecast company  8 . Each weather forecast data is transmitted from the weather forecast company  8  to the contract sites  1 ,  1   a  and  1   b  through the network  10 , and stored in the weather information database  23 . 
   The running record database  25  stores running record data of the air conditioning equipment  39  installed in the contract site  1 . The running record data is obtained by recording data measured by a measuring device attached to each part of the air conditioning equipment, and a running start/stop signal of each device in time series. This running record data is transmitted from the air conditioning equipment management controller  30  periodically or according to a request of the control server  20 . 
   The system configuration database  22  stores system configuration data of the air conditioning equipment of each of the contract sites  1 ,  1   a  and  1   b . As the system configuration data of the air conditioning equipment, there are configuration information and connection information of each device of the air conditioning equipment. 
   The running control means  41  controls transmission of operation plan data of the air conditioning equipment to the air conditioning equipment management controller  30  through the network  10 , stores and manages the running record data of the air conditioning equipment  39  received from the air conditioning equipment management controller  30  through the network  10  in the running record database  25 , calculates a rate to be charged to the contract company  11  from the running record data, calculates rates to be paid to the weather forecast company  8 , the power supply company and the gas supply company, and manages a state of money input/output. The running plan data of the air conditioning equipment contains a running start/stop command, and a target control value of each device provided in the air conditioning equipment. 
   The air conditioning equipment simulator  42  simulates an air conditioner installed in the contract site  1 . Software loaded in the air conditioning equipment simulator  42  includes a program for calculating a load rate of a pump or a freezer to be used from the information of the device connected to the air conditioning equipment  39 , a program for calculating an exchanged heat amount of a cooling coil or a dry coil provided in the air conditioning equipment  39 , and a temperature of water or air in an outlet of the cooling coil or the dry coil, a program for calculating an amount of exchanged heat, and a temperature in an outlet of the heat exchanger, a program for simulating a freezing cycle of the freezer, and a program for calculating a cooled heat amount of the cooling tower, and a temperature of cold water in an outlet of the cooling tower. 
   The air conditioning equipment simulator  42  calculates a partial load rate, consumption of power and consumption of fuel of each device from data on, for example a temperature and humidity of an outside air, a cooling load and a control target value of each device, by referring to the device characteristic data stored in the device information database  24 , and the air conditioning equipment system configuration data of the contract site  1  stored in the device configuration database  22 . In addition, the air conditioning equipment simulator  42  calculates running costs following the consumption of power and the consumption of fuel by referring to the power rate data, the gas rate data and the oil price data stored in the fuel/power rate database. 
   When fuel consumption of the absorption freezer  32  and power consumption of the turbo freezer  33  are calculated from the cooling load, if a parameter value necessary for calculating a freezing cycle such as heat transfer performance of an evaporator or a condenser provided in each freezer is known, the consumption of power is calculated by using a cycle simulator. If such a parameter value necessary for freezing cycle calculation is not known, the consumption of power is calculated by using a relation between the cooling load and the power consumption of the turbo freezer  33 , described later with reference to  FIG. 15 . 
   The device characteristic correction means  43  corrects device characteristic data of the air conditioning equipment by referring to the running record data of the air conditioning equipment stored in the running record database  25 , and then stores the corrected data in the device information database  24 . A change made in the device characteristic because of deterioration of the device is recorded. The operation method optimizing means  44  searches a method for operating the air conditioning equipment installed in the contract site  1  so as to minimize running costs, and makes running plan data. The equipment designing support means  45  searches an air conditioning equipment configuration, which reduces total costs including initial costs, running costs, maintenance costs, and disposal costs, when designing or replacing the air conditioning equipment. 
   A planning engineer of the service provider company  2  makes an operation plan, a maintenance plan, or a replacement plan for the air conditioning equipment  39  provided in the contract sites  1 ,  1   a  and  1   b  by using the control server  20 , and designs air conditioning equipment for a new contract site. The control server  20  of the service provider company  2  stores the fuel/power rate database  21 , the device information database  24 , the system configuration database  22 , the running record database  25 , and the weather information database  23 . When the air conditioning equipment of the new contact site is designed, if there is a contract site currently using a similar device or having used the similar device in the past, and data accumulated in this contract site can be used, the air conditioning equipment can be designed in detail by using the accumulated data. 
   Since the device characteristic including the running record data of the other contract site using the similar device can be examined, a more accurate operation plan can be made. In addition, when maintenance is necessary, if the similar device is used, a similar running history tendency is exhibited. Thus, when similar devices are used by a plurality of contract sites, a maintenance plan can be made by using the stored past running history tendency needing maintenance. As contract conditions of fuel power rates are stored en block in the fuel/power rate database  21 , by selecting a period of small fuel or power consumption so as to consume more fuel or power, fuel or power can be bought at low costs. 
     FIG. 2  shows in detail the air conditioning equipment management controller  30  of  FIG. 1 . The air conditioning equipment management controller  30  has hardware including communication means  61  for controlling communications through the network  10 , input/output means  65 , e.g., a display, a keyboard and a mouse, storage means  62  such as a hard disk, calculation means  63  including a microcomputer, and air conditioning equipment communication means  64  for controlling communications with the air conditioning equipment  39 . Air conditioning equipment management control means  66  for operating the air conditioning equipment is software. 
   The storage means  62  stores running record data  69 , and weather forecast data  68  and running plan data  67  transmitted from the control server  20  of the service provider company  2 . The air conditioning equipment communication means  64  of the air conditioning equipment management controller  30  transmits/receives data of each device provided in the air conditioning equipment  39  through the air conditioning equipment communication line  38 . 
   The air conditioning equipment management controller  66  manages and controls the air conditioning equipment  39 . The air conditioning equipment  39  is controlled by referring to the running plan data  67  transmitted from the control server  20  of the service provider company  2  and stored in the storage means  62 . Also, a measurement value measured by a measuring device and a running value of each device are stored as the running record data  68  in the storage means  62 . The air conditioning equipment management control means  66  receives the running plan data and the weather forecast data transmitted from the control server  20 , and transmits the running record data to the control server. 
   A manager of the contract site  1  operates the input/output means  65  to check a running state of the air conditioning equipment  39  or the measurement value of the measuring device, and accesses information regarding the fuel/power rate database  21 , the device information database  24 , the system configuration database  22 , and the running record database  25  of the control server. In addition, the operation control means  41 , the air conditioning equipment simulator  42 , the device characteristic correction means  43 , the operation method optimizing means  44 , and the equipment designing support means  45  of the control server are used. 
     FIG. 3  shows an example of the air conditioning equipment  39  of the contract site  1 . The air conditioning equipment  39  includes the absorption and turbo freezers  32  and  33 . These freezers  32  and  33  cool cold water, and the cooling load is cooled by the cooled cold water. The cold water is stored in a cold water tank  460 . 
   Now, a device for producing this cold water is described by referring to  FIG. 3 . Cooling water of the absorption freezer  32  is guided to a cooling tower  310  by a cooling water pump  340 , and cooled. Similarly, cooling water of the turbo freezer  33  is guided to a cooling tower  311  by a cooling water pump  341 , and cooled. A cold water primary pump  342  driven by an inverter  400  guides the cold water from the cold water tank  460  to the absorption freezer  32 . Similarly, a cold water primary pump  343  driven by an inverter  431  guides the cold water from the cold water tank  460  to the turbo freezer  33 . Instead of changing a load rate by using the inverters  400  and  431 , three-way valves  860  and  861  may be respectively provided in the absorption and turbo freezers  32  and  33  and, by controlling these three-way valves  860  and  861 , load rates of the respective freezers may be changed. A detail will be described later. 
   In the absorption freezer  32 , its not-shown controller controls the absorption freezer  32  such that a value detected by a cold water outlet temperature sensor  806  can be equal to a preset target temperature. Similarly, in the turbo freezer  33 , its not-shown controller controls the turbo freezer  33  such that a value detected by a cold water outlet temperature sensor  807  can be equal to a target temperature. In the air conditioning equipment of the embodiment, a target temperature is set to 7° C. The target temperature can be changed by a command from the air conditioning equipment management controller  30 . 
   The following elements are attached to the absorption freezer  32 : a temperature sensor  808  for detecting a cold water inlet temperature; the temperature sensor  806  for detecting a cold water outlet temperature; a flow meter  830  for detecting a cold water flow rate; a temperature sensor  804  for detecting a cooling water inlet temperature; a temperature sensor  802  for detecting a cooling water outlet temperature; and a flow meter  834  for detecting a cooling water flow rate. The following elements are attached to the turbo freezer: a temperature sensor  809  for detecting a cold water inlet temperature; the temperature sensor  807  for detecting a cold water outlet temperature; a flow meter  831  for detecting a cold water flow rate; a temperature sensor  805  for detecting a cooling water inlet temperature; a temperature sensor  803  for detecting a cooling water outlet temperature; and a flow meter  835  for detecting a cooling water flow rate. Outputs of the temperature sensors  802  to  809  and the flow meters  830  and  831  are used for calculating an amount of cooled heat of the absorption and turbo freezers  32  and  33 . 
   An amount of heat Q32 (kW) for cooling of the absorption freezer  32  is calculated by the following equation (1):
 
 Q 32 =cp×ρ×W 830/60×( T 808 −T 806)  (1)
 
   In the equation (1), Q32 denotes a cooled heat amount (kW) of the absorption freezer  32 ; cp specified heat at constant pressure for water (kl/kg° C.); ρ a water density (kg/m3); W830 a measurement value (m3/mon.) of the flow meter  830 ; T806 a measurement value (° C.) of a thermometer  806 ; and T808 a measurement value (° C.) of a thermometer T808. 
   In the pumps  340  to  343  for circulating cold water and cooling water, since there is a fixed relation between a flow rate and a current, a flow rate may be calculated by connecting am ammeter to the cold water primary pump  342 , and using a value measured by this ammeter, a current of the pump and device characteristic data of the pump. If a flow rate is obtained by using the current of the pump and the device characteristic data of the pump, costs can be reduced because the ammeter is more inexpensive than the flow meter. However, accuracy is lower compared with the flow meter. A cooled heat amount of the turbo freezer  33  can be calculated by a similar method. 
   Amounts of heat cooled by the respective cooling towers  310  and  311  are calculated from temperatures and flow rates detected by the temperature sensors  802  to  805 , and the flow meters  834  and  835 . Data on measurements by these sensors are also used for analyzing device characteristics, and by the device characteristic correction means  43 . 
   Next, description is made of an example of a configuration of a cooling load side as a cold water secondary side. The cold water produced by the absorption and turbo freezers  32  and  33  and stored in the cold water tank  460  is sent to a cold water header  450  by a cold water secondary pump  344 . Then, a part thereof is supplied to a cold water coil  424  provided in an outside air conditioner  430 . A pressure sensor  840  is attached to the cold water header  450 . A pipe for returning cold water to the cold water tank is connected to the cold water header  450 , and an automatic valve  862  is attached to this pipe. The automatic valve  862  is controlled such that a pressure detected by the pressure sensor  840  can be equal to a preset pressure. 
   The outside air conditioner  430  is an air passage formed in a rectangular duct shape and, from a left end part of  FIG. 3 , outside air is captured in this duct by a blower  350 . Dust of the outside air captured by the blower  350  is removed by filters  420  and  422 . A preheating coil  421  is disposed between the filters  420  and  422 ; and in the downstream side of the filter  422 , a humidifier  423 , the blower  350 , a cooling coil  424 , and a reheating coil  425  in this order. A temperature sensor  813  is disposed in the vicinity of the cooling coil  424 . The outside air captured in the outside air conditioner  430  is adjusted for its temperature and humidity to a target temperature and target humidity by the preheating coil  421 , the humidifier  423 , the cooling coil  424  and the reheating coil  425 . The outer air adjusted for its temperature and humidity is guided to a clean room  360 . 
   The cold water guided to the cooling coil  424  of the outside air conditioner  430  is returned through the automatic valve  865  to the cold water tank  460 . The automatic valve  865  is controlled such that a temperature detected by the temperature sensor  813  can be equal to a set temperature. To detect a temperature and a flow rate of the cold water supplied to the cooling coil  424 , a temperature sensor  811  and a flow meter  813  are provided in a cold water supply pipe  458  and, to detect a return temperature, a temperature sensor  812  is provided in a return pipe  459 . 
   To heat the outside air captured into the outside air conditioner  430 , steam is supplied from a not-shown boiler through a pipe  451  to the preheating coil  421 , the humidifier  423  and the reheating coil  425 . To control the amount of steam supplied to such a device based on the temperature and humidity of the outside air captured into the outside air conditioner  430 , detected by a not-shown sensor, an automatic valve  870  is attached to a downstream side of the preheating coil  421 ; an automatic valve  871  to an upstream side of the humidifier  423 ; and an automatic valve  872  to a downstream side of the reheating coil  425 . 
   Water having its temperature lowered by heat exchanging of each device, and steam condensed, is returned through a pipe  452  to the boiler. A flow meter  835  and a temperature sensor  822  are attached to the steam supply pipe  451 ; and a flow meter  836  and a temperature sensor  823  to the condensed water return pipe  452 . 
   A part of the cold water supplied to the cold water header  450  is used for cooling air in the clean room  360 . A heat exchanger  455  for dry coil cooling water is attached to a cold water pipe  471  branched from the cold water pipe  458 . The outside air distributed in the clean room  360  is heat-exchanged with cooling water circulated in a cooling water pipe  472  by a dry coil  427 . This cooling water is heat-exchanged with cold water distributed in the cold water pipe  471  by the heat exchanger  455  for the dry coil cooling water. 
   The amount of cooling water distributed in the dry coil  427  by a dry coil cooling water pump  345  is adjusted by an automatic flow rate adjusting valve  866  such that values detected by a temperature sensor  814  in a dry coil inlet side, a flow meter of the dry coil  427 , and a temperature sensor  816  in a dry coil outlet side can be equal to preset values. The cold water increased in temperature by the heat exchanger  455  for dry coil cooling water is returned from a cold water pipe  459  to the cold water tank  460 . An automatic flow rate adjusting valve  964  provided between the heat exchanger  455  for dry coil cooling water and the cold water pipe  459  is controlled such that a temperature detected by the temperature sensor  814  can be set equal to a preset temperature. 
   Another part of the cold water supplied to the cold water head  450  is passed through the pipe  472  branched from the pipe  458 , and used for cooling a production device  411  installed in the clean room  360 . The cold water distributed through the pipe  472  is heat-exchanged with cooling water for cooling the production device  411  by a heat exchanger  456  for production device cooling water. The cold water increased in temperature by the heat-exchanging with the cooling water is returned from the cold water pipe  459  to the cold water tank  460 . An automatic flow rate adjusting valve  863  is provided between the heat exchanger  456  for production device cooling water and the cold water pipe  459 , and adapted to adjust the amount of cold water distributed in the pipe  459 . 
   The cooling water for cooling the production device  411  is supplied from a production device cooling water tank  461  to the heat exchanger for device cooling water by a device cooling water pump  347 , heat-exchanged with the cold water, and then supplied through a cooling water pipe  473  to the production device  411 . The cooling water having cooled the production device  411  is returned through a cooling water pipe  474  to the production device cooling water tank  461 . The following elements are attached to the cooling water pipe  473 : a temperature sensor  820  for detecting a cooling water inlet temperature; a pressure sensor  841  for detecting an inlet pressure; and a flow meter  834  for detecting the amount of cooling water. A temperature sensor  821  for detecting a cooling water outlet temperature is attached to the cooling water pipe  474 . A pipe is provided, which is branched from the cooling water pipe  473  to return the cooling water to the production device cooling water tank  411 , and an automatic valve  869  is attached to this pipe. This automatic valve  869  is controlled such that a pressure detected by the pressure sensor  841  can be equal to a preset pressure. 
   The outside air captured into the clean room  360  is guided to a filter  426  by fan units  355 ,  355 , . . . , supplied to a partition room  361  disposed in the production device  411  after its dust is removed, forming a down-flow in the partition room  361 . Subsequently, the outside air is passed from a floor surface having a grating to the outside of the partition room  361 , and heat-exchanged with the cooling water by the dry coil  427  to be cooled. A temperature sensor  801  for measuring a temperature in the partition room  361 , and a hygrometer  851  for measuring humidity are respectively provided in proper positions in the partition room  361 . 
   An exchanged heat amount of the cooling coil  424  provided in the outside air conditioner  430  is calculated from detected values of two temperature sensors  811  and  812  and a flow meter  832  provided in the cold water pipe  458 . An exchanged heat amount of the dry coil  427  is calculated from detected values of temperature sensors  814  and  816  and a flow meter  833  provided in the cooling water pipe of the dry coil  427 . A heat amount for cooling of the production device  411  is calculated from detected values of temperature sensors  820  and  821  and a flow meter  834  provided in the cooling water pipes  473  and  474  of the production device  411 . By totaling the above amounts of heat, a cooling load of the entire clean room  360  is obtained. 
   A mass flow rate of steam distributed in the pipe  451  of the outside air conditioner  430  is calculated from detected values of the temperature sensor  822  and the flow meter  835 . Then, a mass flow rate of water distributed in the pipe  452  of the outside air conditioner  430  is calculated from detected values of the temperature sensor  823  and the flow meter  836 . By subtracting the mass flow rate of water distributed in the pipe  452  from the mass flow rate of steam distributed in the pipe  451 , an amount of steam to be used by the hygrometer  423  provided in the outside air conditioner  430  is obtained. 
   From detected values of the temperature sensors  822  and  823  and the flow meter  836  attached to the pipes  451  and  452  of the outside air conditioner  430 , a specific enthalpy of the steam distributed in the pipe  451 , a specific enthalpy of the water distributed in the pipe  452 , and a mass flow rate are calculated. By using these values, a total amount of heat exchanged between the preheating coil  421  and the reheating coil  425  of the outside air conditioner  430  is represented by the following equation (2):
 
( Q 421 +Q 425)= G 452×( h 451 −h 452)  (2)
 
In the equation (2), Q421 denotes an amount of exchanged heat (kW) of, the preheating coil  421 ; Q425 an amount of exchanged heat (kW) of the reheating coil  425 ; G452 a mass flow rate (kg/s) of the water in the pipe  452 ; h451 a specific entropy (kj/kg) of the steam in the pipe  451 ; and h452 a specific entropy (kJ/kg) of the water in the pipe  452 .
 
   The clean room  360  includes a power source  410  for the production device  411 , consumption of power is measured by a wattmeter  855 . Heat generated by a device such as the production device  411  becomes a cooling load of air in the clean room or device cooling water. As most of the power consumed becomes heat, the consumption of power measured by the wattmeter  855  is used for cooling load analysis. To measure a temperature and humidity of the outside air, a thermometer  800  and a hygrometer  850  are provided in an instrument screen  300 . 
   The absorption and turbo freezers  32  and  33 , their respective accompanying cooling towers  310  and  311 , the following elements provided in the air conditioning equipment operation system, i.e., the pumps  340  to  347 , the valves  860  to  872 , the temperature sensors  800  to  825 , the hygrometers  850  and  851 , the flow meters  830  to  836 , and the pressure sensors  840  and  841 , are connected to the air conditioning equipment management controller  30 , or connected with one another by using the air conditioning equipment communication line  38 . By using the air conditioning equipment communication line  38 , running of each device of the air conditioning equipment is started/stopped, and a control target value is changed. Moreover, a detected value of each sensor such as the temperature sensor, the pressure sensor or the flow meter, and a running signal or a stop signal of each device are transmitted. 
   Next, description is made of a method of operating the absorption and turbo freezers  32  and  33  in combination.  FIG. 4  shows a calculation example of a running cost index per a unit amount of cooled heat for a cooling load in each of the absorption and turbo freezers  32  and  33 . A value shown can be calculated by referring to the partial load characteristic data of each of the absorption and turbo freezes  32  and  33  stored in the device information database  24 , and the gas rate and power rate data stored in the fuel/power rate database  21 . 
   A value at 100% of a cooling load is when each of the absorption and turbo freezers  32  and  33  is run by maximum cooling capability. Hereinafter, % indication represents a ratio of the freezer to the maximum cooling capability. In the case of the turbo freezer  33 , efficiency is high if it is operated at a maximum cooling capability point, and the efficiency is lowered as the amount of cooled heat is reduced. On the other hand, in the case of the absorption freezer  32 , a change in efficiency is only slightly increased even when the amount of heat is reduced. In  FIG. 4 , a ratio of coefficients of performance (COP) between the absorption and turbo freezers  32  and  33  during cooling is set to 1:4.7, and a ratio of unit prices between gas and power is set to 1:4.2. 
   In  FIG. 4 , characteristics of the absorption and turbo freezers intersect each other at the amount of cooled heat X. Running costs are lower if the turbo freezer  33  is used when a cooling load is X or higher, and if the abruption freezer  32  is used when a cooling load is X or lower.  FIG. 5  shows an example of operating the absorption and turbo freezers  32  and  33  in combination. Maximum cooling capabilities of the absorption and turbo freezers  32  and  33  are similarly set to 100%. 
   As running costs are lower if the absorption freezer  32  is used up to X % of a cooling load, the absorption freezer  32  is run. When a cooling load is X % or higher and within a range of 100% or lower, running costs are lower if the turbo freezer  33  is used. Thus, the turbo freezer  33  is run. When a cooling load exceeds 100% and reaches 120% or lower, 20% of the cooling load is cooled by the absorption freezer, and a remaining part of the cooling load is cooled by the turbo freezer. When a cooling load is 120% or higher, 100% of the cooling load is cooled by the turbo freezer, and a remaining part of the cooling load is cooled by the absorption freezer. 
     FIG. 6  shows an example of a change in a running cost index per a unit amount of cooled heat when there are two turbo freezers and two absorption freezers, in a case where one turbo freezer and one absorption freezer are run in combination. It is assumed that when the two turbo freezers and the two absorption freezers are used, one freezer is run if a cooling load is 100% or lower, and two freezers are run if a cooling load is larger than 100%; and maximum amounts of cooled heat for the two freezers are equal to each other. 
   At about 155% or higher of a cooling load, running costs are smallest if the two turbo freezers are used. In the range of a cooling load other than this, running costs become smallest by using one each of the absorption and turbo freezers, and running the freezers according to the operation method of  FIG. 5 . 
   The maximum cooling capability of the freezer is set somewhat enough to spare even in summer when a cooling load is large. A ratio of time for running the freezer in a load zone of summer season when a cooling load is largest is small in running time throughout four seasons. In other words, running time is short at near 200% of a cooling load. 
     FIG. 7  shows a change in a cooling load with respect to a specific enthalpy of an outside air in the clean room. A line  970  indicates a total amount of heat generated from the production device  411 , the fan unit  355 , illumination, a worker and the like in the clean room  360 . The heat generated in the clean room  360  is carried away by cooling water distributed through the dry coil  427  and cooling water for cooling the production device. The amount of this heat is represented as a load  974  of the dry coil  427  and a cooling load  973  of the production device. A line  971  indicates a total amount of the heat generated in the clean room and a cooling load of the outside air. Inclination of the line  971  is equivalent to a mass flow rate (kg/s) of introduced outside air. At a point  972 , a cooling load of outside air absorbed from the outside air conditioner  430  is eliminated. 
     FIG. 8  shows an example of a distribution of a cooling load. Use of air conditioning equipment having the cooling load characteristic shown in  FIG. 7  is assumed. Regarding a outside air condition, a condition of one region in Japan is assumed. For each ratio of a cooling load to the maximum cooling capability of the freezer, an accumulated time of an operation by the load, and an accumulated amount of heat are shown. 
   Now, description is made of a method for reducing costs of the air conditioning equipment operation system under the foregoing condition and characteristic.  FIG. 9  shows a method for reducing gas and power rates by using the operation method optimizing means  44 . Gas and power rates fluctuate due to seasonal or external factors. When a temperature or humidity of an outside air is changed even if a cooling load is maintained constant, changes occur in the amounts of cooled heat of the cooling towers  310  and  311  of the freezers. Consequently, a cooling water temperature is changed to cause changes in running costs of the absorption and turbo freezers  32  and  33 . 
   Now, the air conditioning equipment  39  shown in  FIG. 3  is taken as an example. The operation method optimizing means  44  sets time to zero hour as a plan start time (step  800 S). Then, predicted values of a temperature and humidity of outside air are read (step  801 S). For the predicted values of the temperature and humidity of the outside air, forecast values of the weather forecast company  8  are used. If operation time is different from the predicted time of the weather forecast company  8 , a predicted value of operation time is obtained by interpolating data sent from the weather forecast company. 
   A predicted value of a cooling load is calculated (step  802 S). A predicted value of a specific enthalpy of the outside air is calculated based on the predicted values of the temperature and humidity thereof. After the specific enthalpy is obtained, a cooling load is calculated based on the relation between the specific enthalpy and the cooling load of the outside air shown in  FIG. 7 . The relation between the specific enthalpy and the cooling load of the outside air shown in  FIG. 7  is prepared beforehand by a later-described method based on the running record data stored in the running record database  25 . 
   Then, an operation method is set (step  803 S). It is assumed that air conditioning equipment has a characteristic similar to that shown in  FIG. 5 , and a predicted value X of a cooling load is 150%. In this case, since a shortage of cooling capability occurs if only one freezer is used, two freezers are necessary. If X 1  denotes a target amount of cooled heat of the absorption freezer  32 , and X 2  a target amount of cooled heat of the turbo freezer  33 , there are following three possible combinations. Such combinations are stored beforehand in the database.
     (1) X2=100, X1=X−X2   (2) X1=100, X2=X−X2   (3) X1=X/2, X2=X/2   

   Running costs when the operation method (1) is used are calculated by using the air conditioning operation simulator (step  804 S). As the calculated running cots are used again in step  810 S, the running costs are stored in the storage means. This process is executed for all the three operation methods. After all the operation methods (1) to (3) are calculated, the calculation is stopped, and the process proceeds to step  807 S (step  805 S). If there are any cases remaining to be calculated, the process proceeds to step  806 S, where other operation methods are calculated. Results of the calculated three running costs are compared with one another, a most inexpensive operation method is selected, and this operation method is outputted (step  807 S). 
   A candidate operation method of the freezer obtained for each cooling load is as follows: 
   In the case of X≦100, 
   
       
       (A) X1=X, X2=0 
       (B) X1=0, X2=X
 
In the case of 100&lt;X≦120,
 
       (C) X1=20, X2=X−X1 
       (D) X2=20, X1=X−X2 
       (E) X1=X/2, X2=X/2
 
In the case of 120&lt;X≦200,
 
       (F) X2=100, X1=X−X2 
       (G) X1=100, X2=X−X1 
       (H) X1=X/2, X2=X/2 
     
  
   Then, determination is made as to whether time is an operation end time or not (step  808 S). If the time is not the operation end time, the time is advanced by predetermined time (step  809 S). By setting a time interval to be 10 min., the time is advanced by 10 min. This operation is repeated, and an operation plan of one day described for each 10 min., is made. After the operation plan of one day is made, consideration is given to running cots at the time of starting/stopping the device operation (step  810 S). 
   After the operation of the freezer is started by setting an operation method, if an operation method is changed during the same day, running costs occur following the start/stop of the device running. Thus, comparison is made in running costs between the case of changing an operation method and the case of not changing an operation method in a day, and an operation method of lowest running costs is selected. For example, a plan is made in a manner that the turbo freezer is run until 24:00 of a day before a planning day, the turbo freezer is run from 0:00 to 12:00 of the planning day, the absorption freezer is run from 12:00 to 15:00, and the turbo freezer is run from 15:00 to 24:00. In this case, operation methods (4) to (6) described below are compared with one another, and one having lowest running costs is selected.
     (4) The turbo freezer is run from 0:00 to 12:00; the absorption freezer from 12:00 to 15:00; and the turbo freezer from 15:00 to 24:00.   (5) Only the turbo freezer is run continuously from 0:00 to 24:00.   (6) Only the absorption freezer is run continuously from 0:00 to 24:00.   

   Since the calculation result of the running costs was stored in step  804 S of  FIG. 9 , it is not necessary to calculate running costs. Since the turbo freezer is run on a previous day, in the operation method (6) switching to the absorption freezer, or the operation method (4) switching the operated freezer to another in the midway, running costs occur following the operation start/stop of the device. These costs are added. By the operation in step  810 S, the inconvenience of operation switching in a short time can be removed. 
   The operation plan made by the operation method optimizing means  44  is sent as operation plan data through the network  10  to the air conditioning equipment management controller  30 . The operation plan data is composed of “condition” and “operation”, e.g., in a form of “if . . . , then . . . ”. The air conditioning equipment management controller  30  operates the air conditioning equipment based on this operation plan data. At the time of starting the operation, it takes time for the device to be set in a stationary state. The operation plan data is prepared by considering the time of this transient state. In the case of the absorption freezer, 30 min., or less is necessary to reach a stationary state. Thus, to set the absorption freezer in a stationary state at 12:00, operation plan data for starting operation of the absorption freezer by 11:30 is made. 
   The “condition” may be time, a physical quantity obtained from a measurement value of a temperature or the like of the outside air, or a detected value of a cooling load or the like, or a combination thereof. If the “condition” is a combination of the physical quantity calculated from the measurement value of the temperature of the outside air of the time for changing the operation or the detected value of the cooling load, with a time range, an advantage is provided because it is not necessary to change the operation plan data even if an actual temperature and humidity are slightly different timewise from predicted values of a temperature and humidity obtained from weather forecast. For example, if it is planned that “operation of the absorption freezer  32  is started at 10:00, and a cooling load is 95% at this time”, operation plan data, i.e., “when a cooling load is 95% or higher from 9:00 to 11:00, operation of the absorption freezer is started”, is made. Thus, it is possible to deal with a situation where an increase in the temperature of the outside air is somewhat quickened, and a cooling load reaches 95% at 9:30. 
   If the actual temperature and humidity exceed a permissible range obtained from the weather data predicted by the weather forecast company  8 , or if the weather forecast company  9  changes a weather forecast, the operation plan is reviewed. If the actual temperature and humidity are not as predicted, causing a shortage of cooling capability of the freezer, the freezer that has not been operated is run. This setting is prestored in the air conditioning equipment management control means  66  of the air conditioning equipment management controller  30 . When this setting is executed, the operation plan is reviewed. 
   Each of  FIGS. 10 and 11  shows an example of an operation plan displayed on a control monitor of an air control monitor of the air conditioning equipment management controller  30 . The planning engineer of the service provider company  2  verifies the operation plan and predicted and measurement values of a cooling load by using the input/output means of the control server  20 ; the manager of the contract site  1  by using input/output means  65  of the air conditioning equipment management controller  30 . The predicted and measurement values of the cooling load, a current time and a predicted value of running costs are displayed. In  FIG. 10 , predicted values of cooled heat amounts of the absorption and turbo freezers  32  and  33  are also displayed. In  FIG. 11 , maximum values of cooling capabilities of the absorption and turbo freezers  32  and  33  are also displayed. 
   A current time in the drawing is 22:30 of Jul. 1, 2001 and, from a screen of  FIG. 11 , it can be seen that a predicted value of a cooling load becomes 100% around 9:10 of July 2, causing a shortage of cooling capability in the case of using only the turbo freezer. As it takes 30 min., or less to reach a stationary state from the operation state of the absorption freezer  32 , the absorption freezer  32  may be actuated to compensate for cooling capability at 8:40. Since a cooling load becomes 94% at 8:40, it is planned that the operation of the absorption freezer  32  is started when the cooling load becomes 94%. When the cooling load is 100% or lower continuously for 30 min., the absorption freezer  32  is stopped. A condition where the cooling load is 100% or lower continuously for 30 min., is set in order to prevent repetition of an operation start and stop in a short time. 
   From a screen of  FIG. 10 , distributed states of the cooling loads of the absorption and turbo freezers  32  and  33 . The cooling loads of the absorption and turbo freezers  32  and  33  are distributed by controlling the three-way valves  860  and  861  in such a way as to set inlet temperatures according to the cooling loads of the respective freezers, the three-valves  860  and  861  having been controlled such that cold water inlet temperatures detected by the temperature sensors  808  and  809  provided in the cold water pipes of the respective freezers can be set equal to the target temperature 7° C. A target value of a cold water inlet temperature of the absorption freezer  32  is obtained by the following equation (3):
 
 Tt 808 =T 806 +Qt 32/( cp×ρ×w 830)  (3)
 
In the equation (3), Qt32 denotes a target amount of cooled heat (kW) of the absorption freezer; cp specified heat at constant pressure of water (kJ/kg° C.); ρ a water density (kg/m3); w830 a measurement value (m3/min.) of the flow meter  830 ; T806 a measurement value (° C.) of the thermometer  806 ; and Tt808 a target value (° C.) of a cold water inlet temperature of the absorption freezer  32 . For the turbo freezer  33 , calculation is similarly carried out.
 
   In the foregoing embodiment, the cooling loads of the turbo and absorption freezers  33  and  32  are distributed by using the three-way valves  860  and  861 . However, the cooling loads can also be distributed by setting the cold water primary pumps  342  and  343  as pumps to be driven by the inverters  400  and  431 . Now, this method is described. By the inverters  400  and  431 , cold water flow rates of the cold water primary pumps  342  and  343  are changed. A ratio of cooled heat amounts between the absorption and turbo freezers  32  and  33  is changed according to a ratio of cold water flow rates between the absorption and turbo freezers  32  and  33 . For example, to set a ratio of cooled heat amounts between the absorption and turbo freezers  32  and  33  to 2:10, frequencies of the inverters  400  and  431  are changed in such a way as to set a ratio of cold water flow rates between the cold water primary pumps  342  and  343  to 2:10. Since the use of the inverters  400  and  431  enables proper flow rates to be realized by proper motive power, running costs can be reduced. 
   Each of  FIGS. 12 and 13  shows optimization of air conditioner designing carried out by using the equipment designing support means  45 . By using the annual temperature and humidity fluctuation data stored in the weather database, and the relation of the cooling load to the specific enthalpy of the outside air shown in  FIG. 7 , an annular cooling load pattern is formed in step  901 . In a designing stage, a relation is set between a specific enthalpy of outside air and a cooling load is set as follows. 
   That is, cooling loads  973  and  974  of dry coil cooling water and production device cooling water are caused by heat generated from the production device  411  in the clean room  360 , heat from the fan unit  355 , and heat from illumination and the like. Among the amount of heat generated from the production device  411 , an amount of heat cooled by the production device cooling water is estimated to be set as the cooling load  974  of the production device cooling water. The amount of heat from the production device  411  in the clean room  360 , the amount of heat from the fan unit  355 , and the amount of heat from the illumination or the like are estimated. The cooling load  974  of the production device cooling water is subtracted from the total amount thereof to be set as the cooling load  973  of the dry coil cooling water. 
   In  FIG. 7 , inclination of a cooling load  975  of the introduced outside air is equivalent to a mass flow rate (kg/s) of the introduced outside air. A specific enthalpy at the point  972  where the lien  971  of the cooling load of the introduced out side air intersects the line  970  of a sum of the cooling loads  974  and  973  of the dry coil cooling water and the device cooling water is set as a specific enthalpy of air to be cooled by the cooling coil  424  of the outside air conditioner  430 . 
   In step  902 , a connection relation among the individual devices of the air conditioning equipment  39  is set. A designer enters the following bits of information by using an editor installed in a computer: type information for each device such as the pump, the freezer, or the temperature sensor, physical connection information indicating that cold water discharged from the pump is guided to the freezer, and control information indicating that a detected value of the temperature sensor is set equal to a set temperature as a control target value. 
   In step  903 , a type and the number of device are set. One air conditioning equipment is constructed by referring to the device configuration dataset registered in the device information database  24 .  FIG. 13  shows an example of such a device configuration dataset. The device configuration dataset includes data on a type of each device, and the number thereof. One to be used for the air conditioning equipment is selected from the devices registered in the device information database  24 , and entered to items of the device configuration dataset. If the device to be used is not registered in the device information database  24 , this device is newly registered in the device information database  24 . 
   As the price data is also stored in addition to the device characteristic data in the device information database  24 , in step  904 , initial costs are calculated for each air conditioning equipment by using this price data. Based on the annual cooling load pattern formed in step  901 , in step  905 , an optimum operation method is decided for each cooling load. Running costs when the air conditioning equipment is operated by this method for one year are calculated. As an example of the optimum operation method, an optimization algorithm of the operation plan shown in  FIG. 9  may be cited. 
   In step  906 , calculation is made as to maintenance contract costs, maintenance costs, insurance costs, taxes, costs for disposal, and other costs. In step  907 , calculation is made as to a total of running costs, initial costs and other costs when the air conditioning equipment is operated for the number of years decided by contract. In step  908 , total costs of the foregoing respective costs are ordered from lowest. 
   In step  909 , determination is made as to whether or not to change the device configuration dataset. If the device configuration dataset is changed, the process returns to step  903 . If the device configuration dataset is not changed, the process proceeds to step  910 . In step  910 , determination is made as to whether or not to change the connection relation (flow) of the air conditioning equipment. If the connection relation of the air conditioning equipment is changed, the process returns to step  902 . If not, the process returns to step  911 . In step  911 , the candidate air conditioning equipment are displayed in the lowest order of the total costs. According to the embodiment, since the calculation of the total costs is repeated by changing the flow of the air conditioning equipment or the device configuration dataset, the air conditioning equipment of low total costs can be easily constructed. 
     FIG. 14  shows a example of a change in consumption of power of the turbo freezer  33  with respect to the amount of cooled heat when a cooling water inlet temperature is 28° C. A line  130  indicates a power consumption characteristic measured when the turbo freezer  33  was manufactured. As a result of continuously running the turbo freezer  33 , a heat transfer tube of the evaporator is stained by a stain or the like on cooling water, causing a change in the turbo freezer  33  with time. Consequently, power consumption running record data  131  is shifted upward from the initial characteristic line  130 . Thus, by interpolating or approximating the running record data, a new power consumption characteristic line  132  is obtained. When this power consumption characteristic line  132  is largely shifted from an initial state, consideration is given to whether maintenance is performed or not. The device characteristic correcting means  43  executes such a change. Similarly, when it is determined from the running record data that a change occurred in the device characteristic data prestored for the absorption freezer  32  or the other device because of a change with time or the like, the device characteristic correction means  43  corrects the stored characteristic data. 
     FIG. 15  shows an example of a change in a cooling load of the cooling coil  424  with respect to a specific enthalpy of an outside air obtained by plotting the running record data. The specific enthalpy of the outside air is calculated from measurement values of the thermometer  800  and the hygrometer  850  installed in the instrument screen  300 , and a cooling load of the introduced outside air is calculated based on detected values of the temperature sensors  811  and  812  and the flow meter  832 . It can be seen that the cooling load of the introduced outside air cooled by the cooling coil has a linear relation  161  with the specific enthalpy of the outside air. This relation  161  is obtained by approximating the running record data by at least a square. This approximation equation is used for calculating the predicted value of the cooling load in step  802 S of the operation plan optimization algorithm shown in  FIG. 9 . Also, it is used for replacement consideration described later. 
   The cooling loads  974  and  975  of the dry coil cooling water and the device cooling water shown in  FIG. 7  are substantially constant as long as no changes occur in a production volume or production equipment. Accordingly, an average value is obtained from the running record data among production systems. In the example of the air conditioning equipment shown in  FIG. 3 , the cooling load  974  of the dry coil cooling water is calculated from the detected values of the temperature sensors  814  and  816 , and the flow meter  833 . Similarly, the cooling load  975  of the production device cooling water is calculated from the detected values of the temperature sensors  820  and  821 , and the flow meter  834 . When the predicted value of the cooling load is obtained by using the running plan optimization algorithm shown in  FIG. 9  in step  802 S, if a production state is considered to be similar to that of a previous day, values of the previous day may be used for the cooling loads  974  and  97  of the dry coil cooling water and the production device cooling water. 
   When a highly efficient device is developed or a great change occurs from the cooling load during the designing of the air conditioning equipment, replacement of the equipment is considered according to the flow shown in  FIG. 13 . Here, description is made only of a difference between replacement consideration and equipment designing. 
   The cooling load  975  of the introduced outside air is obtained from the drawing of the cooling load of the introduced outside air with respect to the specific enthalpy of the outside air, the example of which is shown in  FIG. 14 , prepared by the device characteristic correction means  43 . The cooling loads  974  and  973  of the dry coil cooling water and the device cooling water are obtained from the past running record data. An annual change in the temperature and humidity of the outside air is obtained from the past data on the temperature and humidity of the outside air as in the case of equipment designing. By using these values, in step  901 , an annual cooling load pattern is formed. 
   Total costs for the number of years set in the current equipment are calculated. In this case, initial costs are assumed to be 0. Steps  905  to  911  of  FIG. 13  are executed as in the case of equipment designing. Returning to step  902 , if changes are necessary, the flow of the air conditioning equipment is changed in step  902 , and the type of each device, and the number of devices are changed in step  903 . 
   If replacement is assumed, initial costs are set as costs necessary for the replacement. In step  904 , costs necessary for the replacement are calculated. Steps  905  to  911  are executed as in the case of equipment designing. When total costs in the case of replacement are lower than total costs of the current equipment, since replacement costs can be recovered in a period shorter than the number of years previously set in step  907 , the replacement is carried out. 
   Each of  FIGS. 16 and 17  shows a procedure when a contract is started. The service provider company  2  owns the air conditioning equipment  39  and the air conditioning equipment management controller  30 . The service provider company  2  supplies cold water to the contract company  11 , and receives payment from the contact company  11  according to the supplied amount of cold water. Accordingly, the contract company  11  can conserve energy and save costs for the air conditioning equipment without making any initial investments. In  FIG. 16 , upon receiving an order from the contract company  11  ( 601 ), the service provider company  2  investigates a cooling load of the contract site  1  ( 602 ), and obtains cooling load data ( 603 ). In this case, running costs of existing air conditioning equipment are investigated, and running costs per a unit amount of heat for the equipment are calculated. The service provider company  2  roughly designs air conditioning equipment ( 604 ), requests a manufacturing company  3  to provide information regarding a device characteristic or the like of a constituting device, and an estimate ( 605 ), and receives the information ( 606 ). The service provider company  2  negotiates a load of fund for buying the devices with a financial company  7  ( 607 ). In addition, the service provider company  2  negotiates contract terms for a power supply condition and a rate, a gas supply condition and a rate, and weather forecast supply condition with the power supply company  5 , the gas supply company  4 , and the weather forecast company  8  ( 608 ). 
   The service provider company  2  designs equipment in detail by using the equipment designing support means  45 , and makes contract terms ( 609 ). The service provider company  2  negotiates contract terms with the contract company  11  ( 610 ). If no agreement is reached on the contact terms, then the process returns to  605  for reexamination. If an agreement is reached on the contract terms, contracts are established ( 611 , and  612 ). 
   If the contract company  11  has existing air conditioning equipment, and parts thereof are used, the service company  2  buys a device to be used from the contract company  11  or makes a lease contract ( 612 ). The service provider company  2  orders air conditioning equipment to the manufacturing company  3  ( 613 ), and installs the air conditioning equipment  39  and the air conditioning equipment management controller  30  in the contract site  1  ( 614 ). Moreover, the service provider company  2  makes a load contract with the financial company  7  for payment of the air conditioning equipment  39  and the air conditioning equipment management controller  30  ( 615 ), and obtain a loan from the financial company  7  ( 616 ). 
   The service provider company  2  pays for the air conditioning equipment  39  and the air conditioning equipment management controller  30  to the manufacturing company  3  ( 617 ). If the existing air conditioning equipment is bought from the contract company  11 , payment is made to the contract company  11 . The service provider company  2  makes a power supply contract, a gas supply contract, and weather forecast supply contract with the power supply company  5 , the gas supply company  4 , and the weather forecast company  8  ( 618 ). 
     FIG. 17  shows a procedure for a normal operation. The service provider company  2  receives the running record data of the air conditioning equipment  39  from the air conditioning equipment management controller  30  installed in the contract site  1  through the network  10 . The service provider company  2  receives the weather forecast data from the weather forecast company  8  through the network  10 . Then, an operation method of lowest running costs is obtained by using the operation method optimizing means  44 . Operation plan data is prepared by using the obtained operation method ( 632 ). 
   The service provider company  2  transmits the prepared operation plan data, and time series data of the weather forecast data received from the weather forecast company to the air conditioning equipment management controller  30  of the contract site  1 . Also, the service provider company  2  notifies a operation state to the contract company  11  ( 634 ), the operation state including the total amount of heat for cooling, the total amount of heat for heating and the amount of used steam thus far, a rate of use, the amount of heat for cooling and the amount of heat for heating thus far, a change with time in a mass flow rate of steam and the like. 
   The rate of use is obtained by adding a specific charge to a fixed basic monthly rate, the specific charge being obtained by multiplying an accumulated use amount of heat for cooling or heating and an accumulated use amount of steam with unit prices. The amount of heat for cooling is a sum of the amount of heat (including latent heat during dehumidifying) obtained by cooling air introduced into the outside air conditioner  430  by the cooling coil  424 , the amount of heat obtained by cooling air in the clean room  360  by the dry coil  426 , and the amount of heat obtained by cooling the production device  411  by device cooling water. The amount of heat for heating is obtained by heating the air introduced into the outside air conditioner  430  by steam distributed in the preheating coil  421  and the reheating coil  425 . The steam use amount is the amount of steam used by the humidifier  423 . 
   A basic rate is set low for a contract site where annular cooling load fluctuation is small, while a basic rate is set high for a contract site where annual cooling load fluctuation is large, and a difference between an annual average cooling load and a cooling load at a peak time is large. Alternatively, a basic rate is set higher as a cooling load at a peak time is larger. Basic rates are similarly set for the amount of heated heat and the steam use amount. 
   Determination is made as to whether it is a rate payment day or not in step  635 . If it is not a rate payment day, the process returns to step  630 . If it is a rate payment day, then a rate is charged to the contract company  11  in step  636 . Then, the service provider company  2  receives payment from the contract company  11  in step  637 . The rate charged to the contract company  11  is a result of subtracting a land rental rate or the like from the use rate, that is, subtracting payment to the contract company  11 . 
   The service provider company  2  pays for the weather forecast supply rate to the weather forecast company  8  in step  638 . Then, the service provider company  2  pays for the power supply rate to the power supply company in step  639 ; for the gas rate to the gas supply company in step  640 ; and for the loan to the financial company  7  in step  641 . 
   Now, description is made of a case where the contract site  1  owns the air conditioning equipment  39 . In this case, the service provider company  2  reduces running costs by improving efficiency of the air conditioning equipment  39  of the contract site  1 , and the reduced cost amount is divided between the contract company  11  and the service provider company  2 . Running costs (yen/MJ) per a unit amount of heat before operation of the service provider company  2  is calculated by the following equation (4):
 
 A 1=( B 1 +C 1)/ D 1  (4)
 
   In the equation (4), A1 denotes running costs (yen/MJ) per a unit amount of heat before the operation of the service provider company  2 ; B1 an annual gas rate (yen/year) before the operation of the service provider company  2 ; C1 an annual power rate (yen/year) before the operation of the service provider company  2 ; and D1 an annual total amount of cooled heat (MJ/year) before the operation of the service provider company  2 . The amount of cooled heat D1 (MJ/year) is a value obtained by measuring performed by a measuring device attached before the service provider company  2  operates the air conditioning equipment. Thus, before the operation start of the service provider company  2 , the running costs A1 can be accurately obtained. Instead of measuring the amount of cooled heat, estimation may be made from data owned by the contract company  11 . Since it owns various data for the other contract sites, the service provider company  2  can estimate running costs per a unit amount of heat by using data of the other contract sites similar in equipment configuration. 
   A reduced amount of running costs is calculated by using the following equation (5):
 
 M 2 =D 2 ×A 1−( B 2 +C 2 +E 2)  (5)
 
Here, M2 denotes a reduced amount (yen/month) of running costs of one month; B2 a gas rate (yen/month) of one month; C2 a power rate (yen/month) of one month; E2 other costs (yen/month) including depreciation and interest rates of one month; and D2 a total amount of cooled heat (MJ/year) of one month.
 
   The reduced amount M2 (yen/month) of the running costs obtained as a result of the operation of the service provider company is divided between the contract company  11  and the service provider company  2  at a ratio decided by the contract. Similar calculations are made for the total amount of heated heat and the steam use amount. If an operation state is bad, the reduced amount M2 (yen/month) of the running costs of one month becomes minus. Thus, risk burdens are decided beforehand between the contract company  1  and the service provider company  2 . 
     FIG. 18  shows another embodiment of the invention. This embodiment is different from the embodiment shown in  FIG. 3  is that cooling water of the production device  411 , and cooling water of the dry coil  427  disposed in the clean room  360  are heat-exchanged with cooing water circulated in the cooling towers  312  and  313 . That is, the cooling water distributed through the dry coil  427  is passed from the valve  866  through the temperature sensor  816 , and heat-exchanged with the cooling water circulating in the cooling tower  312  by the heat exchanger  457  to be cooled. The cooled water is passed from the temperature sensor  815  through the dry coil cooling water pump  345 , and sent to the dry coil cooling water heat exchanger  455 . A three-way valve  867  is provided in the midway of a pipe for the cooling water circulating in the cooling tower  312 , and one side of the three-way valve  867  is connected to a bypass pipe of the heat exchanger  457 . In the cooling water circulation pipe of the cooling tower  312 , a pump  346  and a temperature sensor  817  for detecting a cooling water outlet temperature are provided. 
   Cooling water having cooled the production device  411  and held in the production device cooling water tank  461  is guided to the cooling tower  313  by a pump  348 . The following elements are provided in the pipe of cooling water circulating in the cooling tower  313 : a temperature sensor  818  for detecting a temperature out of the cooling tower  313 ; a three-way valve  868  located downstream of this temperature sensor, and connected to a bypass pipe bypassing the cooling tower  313 ; and a temperature sensor  819  located downstream of the three-way valve for detecting a temperature of cooling water. The three-way valves  867  and  869  are controlled such that temperatures detected by the temperature sensors  816  and  819  can be equal to set temperatures. In order to prevent temperatures of cooling water in outlets of the cooling towers  312  and  323  from becoming too low, fans of the cooling towers  312  and  313  are subjected to ON/OFF control or rotational speed control according to detected values of the temperature sensors  817  and  818 . 
   In the configuration of the embodiment, the number of cooling towers is increased compared with the case of the configuration of  FIG. 3 . However, cooling capability can be accordingly increased, making it possible to deal with a sudden demand increase. 
     FIG. 19  shows a relation between a wet bulb temperature of outside air and an amount of cooled heat detected by the cooling towers  312  and  313 . Operation plans are made for the cooling towers  312  and  313  based on changes in a temperature and humidity of the outside air and, based on annual temperature and humidity changes in the contract site, air conditioning equipment is designed in such a way as to reduce total costs. 
     FIG. 20  shows a relation between the wet bulb temperature of the outside air and running costs per a unit amount of heat for the cooling towers  312  and  313 . The running costs include power consumption of the cooling tower  312  and a circulation pump. As compared with running costs per a unit amount of heat for the absorption and turbo freezers  32  and  33  shown in  FIG. 5 , running costs per a unit amount of heat for the cooling towers  312  and  313  may be lower depending on a wet bulb temperature of the outside air. In such a case, the cooling towers  312  and  313  are operated to reduce running costs. 
   To select operation methods of the cooling towers  312  and  313 , a combination of an operation and a stop for each of the cooling towers  312  and  313  is made. An optimum operation plan is made according to the operation flow shown in  FIG. 9 . Specifically, an example when a cooling load X of the freezer becomes 100% or lower is shown. 
   In the case of X≦100, 
   
       
       (11) X1=X, X2=0, the cooling towers  312  and  313  are operated. 
       (12) X1=0, X2=X, the cooling towers  312  and  313  are operated. 
       (13) X1=X, X2=0, the cooling tower  312  is operated, but the cooling tower  313  is stopped. 
       (14) X1=0, X2=X, the cooling tower  312  is operated, but the cooling tower  313  is stopped. 
       (15) X1=X, X2=0, the cooling tower  312  is stopped, but the cooling tower  313  is operated. 
       (16) X1=0, X2=X, the cooling tower  312  is stopped, but the cooling tower  313  is operated. 
       (17) X1=X, X2=0, the cooling towers  312  and  313  are stopped. 
       (18) X1=0, X2=X, the cooling towers  312  and  313  are stopped. 
     
  
   The operations of the cooling towers  312  and  313  are decided depending on a wet bulb temperature of the outside air. Whether the cooling towers  312  and  313  cane operated or not is decided based on device characteristic data. When the cooling towers  312  and  313  can be operated, amounts of heat to be cooled by the cooling towers  312  and  313  are obtained. A value obtained by subtracting the amount of heat cooled by the cooling towers  312  and  313  from an entire cooling load is set as a cooling load X of the freezer, and target amounts of cooled heat are set for the absorption and turbo freezers  32  and  33 . 
     FIG. 21  shows a relation between a dew-point temperature and an amount of cooled heat of the cooling tower when a cooling tower outlet temperature is 14° C. A line  140  indicates a characteristic line during manufacturing; and a line  141  a line connecting running record data. When the running record data is shifted by a predetermined amount from the initial characteristic line  140 , the characteristic line is corrected to the line  141  obtained from the running record data. 
   Now, description is made of another method for calculating a specific charge by referring to  FIG. 22 .  FIG. 22  shows a cold water temperature, and a unit price per cold water weight. As a cold water temperature is lower, a cold water unit price is set higher. A reason is that greater energy is necessary for lower temperature cold water. Regarding cooling loads of the cold water coil  424 , the dry coil  426 , and the production device  411 , a specific charge is calculated by the following equation (6):
 
 MM =( MM 1 −MM 2)× WW /60 ×TI×ρ   (6)
 
   In the equation (6), MM denotes a specific charge (yen) of cold water; MM1 a unit price (yen/kg) corresponding to a temperature of supplied cold water; MM2 a unit price (yen/kg) corresponding to a temperature of returned cold water; WW a flow rate (m3/min.); TI time (s); and ρ a water density (kg/m3). 
   Now, as a modified example of the embodiment shown in  FIG. 18 , a case of increasing the respective numbers of cooling towers  310  and  311  is described. In addition to the cooling towers  310  and  311 , cooling towers  312  and  313  are increased in number. Accordingly, cold water primary pumps  342  and  343 , and cooling water pumps  340  and  341  are also increased in number. Simple combinations lead to an increase in the number of combinations. However, such a number of combinations can be reduced by considering a characteristic of air conditioning equipment. 
   For example, when a cooling load of the freezer is 280%, by setting the number of freezers to be operated to 4 or more, power supplied to the cold water primary pumps  342  and  343 , the cooling water pumps  340  and  341 , and the cooling towers  310  and  311  to be operated is increased. However, running costs can be reduced by operating only three of the freezers. Accordingly, an operation combination of freezes is set on the assumption that the three freezers are operated. As a result, it is possible to reduce the number of combinations. 
   As apparent from the foregoing, according to the present invention, in the air conditioning equipment operation system provided with the plurality of freezers, since the air conditioning equipment is operated by considering a partial load characteristic of each freezer, and a fuel/power rate, an operation is possible, where running costs with respect to a load can be reduced. It is also possible to realize the air conditioning equipment operation system, where total costs including initial and running cots are reduced. Furthermore, it is possible to realize the operation system capable of supplying low-cost cold water. 
   It should be further understood by those skilled in the art that the following description has been made on embodiments of the invention and that various changes and modifications may be made in the invention without departing from the spirit of the invention and the scope of the appended claims