Abstract:
A system for monitoring equipment operating parameters of a remote system includes a monitor that communicates with a controller of the remote system, and at least one piece of equipment operable within the remote system, and that communicates with the controller. The equipment has at least one associated operating parameter. The monitor compares a present value of the associated operating parameter to a previous value to determine a difference therebetween. The difference is associated with a cost, measuring the cost of operating the equipment at the present operating parameter.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to monitoring equipment operating parameters and, more particularly, to a system for monitoring optimal equipment parameters of equipment for refrigeration, HVAC, lighting, anti-condensate heating, and other systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    Retail outlets, particularly food retailers, require a plurality of systems during operation. Such systems often include refrigeration, HVAC, lighting, anti-condensate heating (ACH), and defrost control systems. Each of these systems include associated equipment to perform various functions. For example, refrigeration systems include compressors, condensers, evaporators, and the like to cool refrigeration cases to a desired temperature.  
           [0003]    The various types of equipment include operating parameters, or set points, at which the equipment operates. The set point defines the operating condition of the equipment and is adjusted to provide a desired output from the equipment. For example, a set point of an electronic pressure regulator is adjusted to maintain a desired pressure within an evaporator of a refrigeration system. Because the equipment of the various systems consume power during their operation, the amount of power consumed by a particular piece of equipment corresponds to the set point value. Thus, if a set point is changed, the amount of power consumed by the equipment correspondingly changes.  
           [0004]    Generally, a retailer configures the particular systems of its associated retail locations to operate at an optimized level. Thus, optimized set points are determined and set, whereby the systems operate in a desired manner, typically efficiently. However, set point changes can occur for various reasons, including maintenance, cleaning, and the like. Often, the set points are not returned to their previous levels, resulting in the systems operating in an undesired manner or at inefficient levels. Traditionally, it is difficult for a retailer to routinely monitor the set points of the systems of its various retail locations. As a result, the systems of the retail locations operating in an undesired manner or at inefficient levels incur significant cost to the retailer over time.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides a method of monitoring optimal equipment operating parameters of a remote system. The method includes monitoring an operating parameter of a piece of equipment of the remote system and communicating the operating parameter to a monitoring system. A present value of the operating parameter is compared to a previous value, and a change is indicated if the present value is different than the previous value.  
           [0006]    Preferably, a difference between the present value and the previous value is determined. The difference is associated with a monetary value to indicate one of an increase and a decrease in cost. Additionally, the monitoring system is accessible by a remote user via a communication network, whereby the remote user is able to review changes and associated costs of the operating parameter.  
           [0007]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limited the scope of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0009]    [0009]FIG. 1 is a schematic illustration of a building system for use with the method for analyzing the building system performance according to the principles of the present invention;  
         [0010]    [0010]FIG. 2 is a schematic illustration of an exemplary refrigeration system according to the principles of the present invention;  
         [0011]    [0011]FIG. 3 is a schematic illustration of an exemplary HVAC system according to the principles of the present invention;  
         [0012]    [0012]FIG. 4 is a schematic illustration of an exemplary lighting system according to the principles of the present invention; and  
         [0013]    [0013]FIG. 5 is a detailed schematic illustration of an exemplary refrigeration system according to the principles of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    The present system for monitoring optimal equipment operating parameters provides a comprehensive building system assessment and energy management solution. The system is particularly applicable to refrigeration, HVAC, lighting, anti-condensate heating (ACH), and defrost control systems. As shown in FIG. 1, an HVAC controller  1  is in communication with a refrigeration controller  2 , an ACH condensate heater controller  3 , and a lighting controller  4 . These components are typically located in a building  5 . Further, the HVAC controller  1  is in communication via communication network  6 , including a modem or internet connection, to a remote monitor  7  at a remote location  8 . As shown, the HVAC controller  1  communicates with the HVAC system, with the refrigeration controller  2 , the ACH controller  3 , and the lighting controller  4 , which respectively communicate with the refrigeration system, the anti-condensate heaters, and lighting system. Although the HVAC controller  1  is shown as a communication gateway between the various controllers  2 ,  3 ,  4  and the remote monitor  7 , it will be appreciated that any of the controllers  1 - 4  can function as a communication gateway. Alternatively, each controller  1 ,  2 ,  3 ,  4  can be connected to a network backbone that has a dedicated communication gateway (such as a personal computer, server computer or other controller) to provide internet, modem or other remote access. It will be appreciated that the illustration of FIG. 1 is merely exemplary, and more or fewer building control systems may be included.  
         [0015]    With reference to FIG. 2, a basic refrigeration system  200  is shown. The refrigeration system  200  includes one or more compressors  210 , condensers  220  and refrigeration fixtures  230 . The condensers  220 , compressors  210 , and refrigeration fixtures  230  communicate with the refrigeration controller  2 . Such communication may be networked, dedicated direct connections or wireless.  
         [0016]    Similarly with FIG. 3, an exemplary HVAC system  300  is shown. As shown, the HVAC controller  1  communicates with a fan  310  and sensors  320 , as well as a cooling apparatus  330 , heating apparatus  340  and damper  350 , if appropriate. The fan  310 , cooling apparatus  330 , heating apparatus  340  and damper  350  communicate with the HVAC controller  1 . Such communication may be networked, dedicated direct connections or wireless.  
         [0017]    [0017]FIG. 4 shows a lighting system  400 . As shown, one or more lighting fixtures  410  communicate with the lighting controller  4 . The lighting fixtures  410  are shown in various areas of the building and its exterior, with some areas including multiple types of fixtures while lighting fixtures for multiple areas may also be similarly controlled. For example, FIG. 4 illustrates a sales area  420 , a department area  430  and a parking lot  440 . The department area  430  includes lighting fixtures  410 , as well as lighting fixtures  410  for display cases  450  therein. The parking lot  440  includes lighting fixtures  410  as well as an exterior sign lighting  460 . The various lighting fixtures  410  are in communication with the lighting controller  4 . Such communication may be networked, dedicated direct connections or wireless.  
         [0018]    With reference to FIG. 5, a detailed block diagram of the exemplary refrigeration system  200  is shown. The refrigeration system  200  includes a plurality of compressors  12  piped together with a common suction header  14  and a discharge header  16  all positioned within a compressor rack  18 . The compressor rack  18  compresses refrigerant vapor that is delivered to an oil separator  36  from which the vapor is delivered via a first line  37  to a hot gas defrost valve  40  and a three-way heat reclaim valve  42 . The hot gas defrost valve  40  enables hot gas to flow to an evaporator (not shown) through liquid line solenoid valve  70  and solenoid valve  68 . The heat reclaim valve  42  enables hot gas to flow to the heat reclaim coils  46  and to a condenser  20  where the refrigerant vapor is liquefied at high pressure.  
         [0019]    A second line  39  of the oil separator  36  delivers gas through a receiver pressure valve  48  to a receiver  52 . The receiver pressure valve  48  ensures the receiver pressure does not drop below a set value. The condenser  20  sends fluid through a condenser flood back valve  58  to the receiver  52 . The condenser flood back valve  58  restricts the flow of liquid to the receiver  52  if the condenser pressure becomes too low. Evaporator pressure regulator (EPR) valves  28  are mechanical control valves used to maintain a minimum evaporator pressure in cases  22 . The EPR valves  28  operate by restricting or opening a control orifice to raise or lower the pressure drop across the valve, thereby maintaining a steady valve inlet (and associated evaporator pressure) even as the evaporator load or rack suction pressure varies in response to the addition or subtraction of compressor capacity or other factors.  
         [0020]    A surge valve  60  enables liquid to bypass the receiver  52  when it is subcooled in the ambient. Accordingly, ambient subcooled liquid joins liquid released from the receiver  52 , and is then delivered to a differential pressure regulator valve  62 . During defrost, the differential pressure regulator valve  62  reduces pressure delivered to the liquid header  64 . This reduced pressure enables reverse flow through the evaporator during defrost. Liquid flows from liquid header  64  via a first line through a liquid branch solenoid valve  66 , which restricts refrigerant to the evaporators during defrost but enables back flow to the liquid header  64 . A second line carries liquid from the liquid header  64  to the hot gas defroster  72  where it exits to an EPR/Sorit valve  74 . The EPR/Sorit valve  74  adjusts so the pressure in the evaporator is greater than the suction header  14  to enable the evaporator to operate at a higher pressure.  
         [0021]    The high-pressure liquid refrigerant leaving liquid branch solenoid valve  66  is delivered to a plurality of refrigeration cases  22  by way of piping  24 . Circuits  26  consisting of a plurality of refrigeration cases  22  operate within a certain temperature range. FIG. 5 illustrates four (4) circuits  26  labeled circuit A, circuit B, circuit C and circuit D. Each circuit  26  is shown consisting of four (4) refrigeration cases  22 . However, those skilled in the art will recognize that any number of circuits  26 , as well as any number of refrigeration cases  22  may be employed within a circuit  26 . As indicated, each circuit  26  will generally operate within a certain temperature range. For example, circuit A may be for frozen food, circuit B may be for dairy, circuit C may be for meat, etc.  
         [0022]    Because the temperature requirement is different for each circuit  26 , each circuit  26  includes a EPR valve  28  that acts to control the evaporator pressure and, hence, the temperature of the refrigerated space in the refrigeration cases  22 . The EPR valves  28  can be electronically or mechanically controlled. Each refrigeration case  22  also includes its own expansion valve (not shown) that may be either a mechanical or an electronic valve for controlling the superheat of the refrigerant. In this regard, refrigerant is delivered by piping to the evaporator in each refrigeration case  22 . The refrigerant passes through an expansion valve where a pressure drop causes the high pressure liquid refrigerant to become a lower pressure combination of liquid and vapor. As the hot air from the refrigeration case  22  moves across the evaporator, the low pressure liquid turns into gas. This low pressure gas is delivered to the pressure regulator  28  associated with that particular circuit  26 . At EPR valves  28 , the pressure is dropped as the gas returns to the compressor rack  18 . At the compressor rack  18 , the low pressure gas is again compressed to a high pressure gas, which is delivered to the condenser  20 , which creates a high pressure liquid to supply to the expansion valve and start the refrigeration cycle over.  
         [0023]    A main refrigeration controller  2  is used and configured or programmed to control the operation of the refrigeration system  200 . The refrigeration controller  2  is preferably an Einstein Area Controller offered by CPC, Inc. of Atlanta, Ga., U.S.A., or any other type of programmable controller which may be programmed, as discussed herein. The refrigeration controller  2  controls the bank of compressors  12  in the compressor rack  18  via an input/output module  32 . The input/output module  32  has relay switches to turn the compressors  12  on and off to provide the desired suction pressure. A separate case controller (not shown), such as a CC-100 case controller, also offered by CPC, Inc. of Atlanta, Ga., U.S.A., may be used to control the superheat of the refrigerant to each refrigeration case  22  via an electronic expansion valve in each refrigeration case  22  by way of a communication network or bus  34 . Alternatively, a mechanical expansion valve may be used in place of the separate case controller. Should separate case controllers be utilized, the main refrigeration controller  2  may be used to configure each separate case controller, also via the communication bus  34 . The communication bus  34  may be a RS-485 communication bus, a LonWorks Echelon bus or any other communication platform that enables the main refrigeration controller  30  and the separate case controllers to receive information from each case  22 .  
         [0024]    Each refrigeration case may have a temperature sensor  44  associated therewith, as shown for circuit B. The temperature sensor  44  can be electronically or wirelessly connected to the controller  2  or the expansion valve for the refrigeration case. Each refrigeration case  22  in the circuit B may have a separate temperature sensor  44  to take average/minimum/maximum temperatures or a single temperature sensor  44  in one refrigeration case  22  within circuit B may be used to control each case  22  in circuit B because all of the refrigeration cases  22  in a given circuit operate in substantially the same temperature range. These temperature inputs are preferably provided to the analog input board  38 , which returns the information to the main refrigeration controller via the communication bus  34 .  
         [0025]    The particular set points of the various equipment of the refrigeration system  200  are preferably set to optimized values to achieve efficient operation of the refrigeration system  200 . These optimized values are benchmark values preferably determined during a system performance analysis. Such a method is disclosed in commonly assigned U.S. Patent Application No. 60/287,458, entitled Building System Performance Analysis, which is expressly incorporated herein by reference. In short, the method includes an examination of existing system conditions and operating parameters using a combination of remote monitoring and on-site technicians. A series of prescribed testing and adjustment procedures are also conducted. Through a continuous follow-up process and associated feedback-loop activities, optimized operating parameters (i.e., set points) of the various equipment are determined to maintain the system in an enhanced performance state. Although the optimized operating parameters of the refrigeration system  200  are preferably determined implementing the method described immediately above, it will be appreciated that other methods may be used.  
         [0026]    While the present invention is discussed in detail below with respect to specific components as contained in refrigeration system  200 , it will be appreciated that the present invention may be employed with other types of systems having configurable components to provide substantially the same results as discussed herein. By way of example, other types of systems include, but are not limited to HVAC, lighting, ACH, and defrost.  
         [0027]    Initially, application-specific operating parameters, or set points, are determined for the equipment of the refrigeration system  200 . These set points include control method (e.g., pressure, temperature), suction float, minimum float point, maximum float point, suction group set point, control sensor offset, condenser set point, and ambient sensor offset. More particularly, the set points preferably include minimum head pressure, air-cooled condenser fan speed, hold-back valve pressure, evaporator condenser sump temperature, receiver pressurization valve, EPR valve pressure, suction pressure, and discharge pressure. As discussed above, these set points are preferably determined implementing the system performance analysis method.  
         [0028]    With regard to the HVAC systems  300 , set points include cooling, heating, dehumidification, cooling override, heating override and fan override. With regard to defrost, set points include number of defrosts per day, defrost duration, termination type and termination temperature. For the lighting system  400 , set points include light level, on time and off time.  
         [0029]    The monitoring method of the present invention initially includes each controller  1 ,  2 ,  3 ,  4  monitoring the equipment set points of their respective systems. It is anticipated that the controllers  1 ,  2 ,  3 ,  4  either continuously monitor the set points, periodically monitor the set points, or are alerted to a set point change. Continuous, and alert monitoring of the set points enable the particular controller to determine the precise time a set point change occurred. Periodically monitoring the set points enables the particular controller to determine a time range, within which a set point change occurred. The remote monitor  7  periodically communicates with the controllers  1 ,  2 ,  3 ,  4  through the communication network  6  to obtain the various set point information.  
         [0030]    The remote monitor  7  stores the set point information in memory for the various systems of building  5 . The remote monitor  7  periodically communicates with the controllers  1 ,  2 ,  3 ,  4  to obtain present set point information. The remote monitor  7  also records the base or benchmark set points for the equipment of the various systems. In this manner, the benchmark set point is stored for informational purposes. The remote monitor  7  initially records the benchmark set point as a prior set point. The remote monitor  7  compares the monitored, or present set point to the prior set point for the individual equipment. In this manner, the remote monitor  7  determines whether a change in any of the set points has occurred. If there is no difference between the present set point and the prior set point, then the remote monitor  7  continues monitoring with no other action. If there is a difference between the present set point and the prior set point, the remote monitor  7  stores into memory the present set point as well as the time that the set point change occurred.  
         [0031]    Once the set point information has been recorded into memory, the remote monitor  7  overwrites the prior set point, recording the present set point as the prior set point. In this manner, the prior set point is consistently updated after a change in set point occurs and continues to be the value compared against to determine whether further changes in set point have occurred.  
         [0032]    It is also anticipated that the controllers  1 ,  2 ,  3 ,  4  can continuously monitor the set point changes in their respective systems and alert the remote monitor of a change in set point. More specifically, the local controllers  1 ,  2 ,  3 ,  4  store the benchmark set point. The controllers initially record the benchmark set point as the prior set point. The controllers compare the monitored, or present set point to the prior set point for the individual equipment. In this manner, the controllers determine whether a change in any of the set points has occurred. If there is no difference between the present set point and the prior set point, then the controllers continue monitoring with no other action. If there is a difference between the present set point and the prior set point, the controllers store into memory the present set point as well as the time that the set point change occurred.  
         [0033]    Once the set point information has been recorded into memory, the controllers overwrite the prior set point, recording the present set point as the prior set point. In this manner, the prior set point is consistently updated after a change in set point occurs and continues to be the value compared against to determine whether further changes in set point have occurred.  
         [0034]    Regardless of whether the local controllers  1 ,  2 ,  3 ,  4  or the remote monitor  7  monitor the set point changes, the remote monitor  7  inputs the set point information into a database. The database is accessible via the communication network  6  by a remote user  9 . The database sorts the set point information such that it is accessible by the remote user  9  in a variety of manners via a web interface. For example, the remote user  9  may select a particular location (e.g., building  5 ) to view the set point changes, and present set point values at that particular location. Additionally, the remote user  9  is able to view the benchmark set points of the various equipment within a particular location, the present set point, and the set point used prior to the benchmark set point. Further, the remote user  9  can access a summary of the set point changes which have occurred across all of the locations. The various set point information is accessible for any of the systems, including the refrigeration system  200 , ACH, defrost, HVAC  300 , and lighting  400  systems.  
         [0035]    The remote monitor  7  further associates the set points and set point changes with a cost. The set points of the various equipment within the systems signal the equipment to operate consuming an associated amount of power. A set point change alters the amount of power required by a piece of equipment to operate. Thus, a comparison of set points can indicate an increase, or decrease in power consumption. Standardized costs are available throughout different regions to determine a cost associated with a particular power consumption rate. More particularly, the remote monitor  7  is able to access a database that maintains a record of power consumption costs for various regions, or even particular locations. The remote monitor  7  is able to determine a rate of power consumption for a particular piece of equipment at the benchmark set point, and compare that to a rate of power consumption at the present set point. If there is a difference between the two, the remote monitor is able to associate this difference with a cost. In this manner, the remote user  9  may determine the effect a set point change has on the overall operating costs of the particular system for a chosen time period (e.g., days, weeks, years, etc.).  
         [0036]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.