Patent Publication Number: US-6209330-B1

Title: Modular air handling system and method for providing cooling

Description:
TECHNICAL FIELD 
     This invention relates generally to air handling systems and, more particularly, to a modular cooling system for conditioning air while utilizing an existing chilled water supply. Though not limited thereto, the present invention is particularly useful in connection with large computer installations which require a continuous or near-continuous supply of conditioned air for reliable operation. 
     BACKGROUND ART 
     Individuals, businesses, and governments have grown increasingly dependent on the services and resources that are made available through the processing of computers and computerized control facilities. In spite of the explosive growth in the utilization of control circuits and personal computers in recent years, many computer applications continue to rely on the services provided by large computer mainframe installations. Such data processing facilities are often in continuous operation, twenty-four hours per day, three hundred and sixty-five days a year. 
     The computer equipment typically found in mainframe computer rooms generates vast amounts of heat and requires a limited temperature environment in which to operate reliably. In addition, a continuous supply of clean air is necessary to prevent the buildup of dust or dirt, which could contaminate the electrical circuits and compromise the reliable operation of the equipment. 
     While the thousands of mainframe computer installations in continuous operation throughout the world attest to the fact that many data processing facilities have provided at least basic cooling and filtration operations, problems still exist. In fact, HVAC (heating, ventilating, air conditioning) systems have been designed and implemented for year-around operation, with energy conservation cycles to take advantage of lower ambient temperatures. Some of these systems are well known to be fully integrated systems that address the cooling and filtration requirements of electronic data processing and control equipment. However, such systems are designed and marketed in a finite number of configurations, such as in 5, 10, 15, etc. ton capacities. Because of the critical nature of the services and resources provided by mainframe data processing systems and because of the finite operating temperatures and humidity in which such equipment can operate reliably, HVAC systems supporting computer facilities have been designed with redundant components in the form of backup compressors, pumps, and fan motors. However, such redundancy raises both the cost and size of such equipment. Furthermore, not all key components in such systems are duplicated, and a failure of any of these elements results in the HVAC system operating at reduced capacity or even being shut down to await parts and repair by skilled personnel. 
     The present invention is directed to overcoming one or more of the problems set forth above. 
     DISCLOSURE OF THE INVENTION 
     In one aspect of this invention, a modular air handling system for producing a supply of cooled air for cooling purposes is disclosed. The modular air handling system includes a module container and a primary duct work mechanism for transporting the air within the module container and a blower module for propelling the air within the primary duct work mechanism, along with a cooling coil module located within the module container, wherein a variable volume and temperature of cooled air is propelled by the blower module to at least one resource that is located external to the module container. 
     In another aspect of the present invention, a method for producing a supply of cooled air to facilities external to a modular air handling system is disclosed. The method includes the steps of housing the primary air handling apparatus of a blower module, a cooling coil module, and a primary duct work mechanism within a module container and cooling a supply of air and propelling a variable volume and temperature of cooled air to at least one resource located external to the module container. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     For a better understanding of the present invention, reference may be made to the accompanying drawing in which: 
     FIG. 1 is a schematic diagram of a modular air handling system. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Referring now to FIG. 1, an external structure for a module container  10  for enclosing the components of an air handling system on all sides, including a top and a bottom, is depicted. The entire air handling system, comprising the container structure, the interior components, and quick-connect couplings as more thoroughly disclosed below will collectively be referred to as the “modular air handling system” or “module”, hereinafter depicted by numeral  100 . 
     The aforementioned sides of the module container  10  may traditionally include four sides of a rectangular structure. However, the module container  10  could also be round or any other known design for enclosing a space for the housing of equipment. It is intended that the entire module  100 , including the module container  10  and internal components and connections is designed and constructed such that it can be moved intact from point of manufacture to an end site and from site to site regardless of location of the site. Such a feature permits complete replacement of the entire module  100  as a unit should any component fail, should the site no longer require the cooling provided by the module  100 , or should the site require a module  100  with more or less cooling capacity. As such, the module  100  may have external connections such as lifting brackets (not shown) to facilitate the moving and loading of the module  100  by crane or other lifting means. Additionally, the module  100  may have wheels, rollers, or similar devices (not shown) operably connected to the bottom or sides of the modular container  10  to facilitate its mobility. By way of illustrative example, the modular container  10  may have nominal dimensions of five feet (5′) deep by seven feet (7′) high by ten feet (10′) in length. However, the dimensions of the modular container  10  are a function of the size and number of components contained within and are not intended to be limited by the exemplary dimensions disclosed above. Given the size of the module container  10 , its containment components including top, bottom, and sides may also be described as ceiling, floor, and walls, respectively. 
     The primary operational component of module  100  is a blower  12 . Although only one blower  12  is shown, any number of blowers may be designed into a comparably-sized module container  10  to provide desired cooling and air volume capacity. The blower  12  propels a supply of air through a supply duct  14  to a cool air loop  16  servicing a facility or equipment (not shown) located in a space  18  external to the module container  10 . The cool air loop  16  includes a supply duct  20  and a return duct  22 , supplying a remote space or equipment with cool air and returning that air to a return duct  24  in a relatively continuous cycle. The remote space or equipment may be located immediately adjacent to the module  100 , in which case the supply duct  20  and the return duct  22  will be relatively short in length. Alternatively, the facility or equipment serviced by the modular air handling system  100  may be located some distance from the module  100 , such as on a different floor within a building or in a building separate from the module  100  location. In such installations, the supply and return ducts  20  and  22 , respectively, will be relatively long. The supply ducts  14  and  20  each terminate at the module container  10  with a quick-connect coupling  26 . The return ducts  22  and  24  each terminate at the module container  10  with a quick-connect coupling  28 . The quick-connect couplings  26  and  28  comprise flexible links and connect/disconnect the air ducts to facilitate the modular features of the inventive system by permitting rapid and convenient connection and disconnection of the module  100  from its surroundings by non-technical personnel, using non-specialized equipment. 
     The resources served by the module  100  may be open space occupied by people, equipment, or both (not shown), in which the module  100  provides cool air to control the temperature within the facility. The supply duct  14  may also provide a supply of cool air to a space beneath the raised floor of a computer room (not shown), thereby providing cooled air to the computer room equipment and space through vents in the raised floor. The temperature and air pressure in the space  18  is detected and reported by two sensors,  30  and  32 , respectively. While not shown in FIG. 1, the system is intended to include any of the sensory systems typically associated with blowers, electric motors, air conditioning systems, fluid chilling systems, and air handling equipment. Such sensory systems, by way of example and not limitation, detect such conditions as power on/off, motor stopped, motor running, air temperature, presence of smoke, air flow, water temperature, water flow, air pressure, and malfunction. 
     Connected to the supply duct  14  on the outlet side of the blower  12  is a sensor  34  for detecting and reporting the temperature of the air supply exiting the blower  12 . The sensor  34  may be connected to a display panel (not shown) as more thoroughly disclosed below. An abnormally high reading by the sensor  34  may indicate a malfunction somewhere in the modular air handling system  100  or may indicate a malfunction or excessive heat in the facility serviced by the module  100 , and a corresponding alarm indication may be signaled as discussed below. Also connected to the supply duct  14  on the outlet side of the blower  12  is a sensor  36  for detecting and reporting any smoke in the air flow exiting the blower  12 . 
     The blower  12  is equipped with a variable volume control  38 , thereby controlling the volume of air propelled by the blower  12  through the supply duct  14  into the external space  18 . The variable volume control  38  may be a variable speed control for the blower  12 , with a slower blower speed resulting in a lesser volume of air propelled by the blower  12  into the cool air loop  16 . Alternatively, the control  38  may be a scroll cone volume control, thereby directly controlling the volume of air propelled through the supply duct  14  by the blower  12 . The volume of air propelled through the supply duct  14  to the external space  18  may also be controlled with a bypass feature that includes a bypass duct  40  that is connected between the supply duct  14  and the return duct  24 . Within the bypass duct  40  is a vane  42 , controlled with a bypass volume control  44 . As less cool air is required by the space  18 , the vane  42  is opened by operation of the bypass volume control  44 , thereby causing part of the air flow exiting the blower  12  to be routed through the bypass duct  40  and reducing the volume of air passing through the supply duct  14  into the supply duct  20  to service the space  18   
     Air from the space  18  is drawn into the module  100  and into the return duct  24  from the return duct  22  through the quick-connect coupling  28  by the suction action of the blower  12 . The temperature and humidity of the return air in the return duct  24  are detected and reported by the two sensors  50  and  52 , respectively. A sensor  54  detects and reports any smoke in the air flow in the return duct  24 . Should either of the sensors  36  or  54  detect the presence of smoke, the system will activate the shut-down and isolation of the modular air handling system  100  by shutting off blower  12  and directing the damper controls  47  and  49  to close vanes  46  and  48  located in supply duct  20  and return duct  22 , respectively. The supply and return duct shut-off vanes  46  and  48 , in addition to isolating the module  100  upon detection of smoke, may be utilized to isolate the modular air handling system  100  for repair or replacement without jeopardizing the supply of cooled air to the space  18 . Providing reliable and redundant cooling systems to critical facilities or equipment located in a space  18  may require multiple modular air handling systems  100 . While only one such module  100  is shown in FIG. 1, any number of modules  100  may be connected in parallel to serve a given space  18 . Isolating one module  100  from the space  18  will not compromise the facilities or equipment located in the space  18 , either because a backup module  100  may be brought online, either manually or automatically, or because the collection of modules  100  serving the space  18  provides sufficient excess cooling capacity. 
     A sensor  56  detects and reports the air pressure differential across a filter  58  located in the return duct  24 . A pressure differential above a pre-determined level is indicative that the filter  58  requires changing or cleaning. Following filtration, the air in the return duct  24  is drawn across a chilled fluid coil  60 , where the air is cooled. The air continues through the blower  12  and exits the module  100  at the quick-connect coupling  26  to provide cooled air to facilities and equipment located external to the module  100  as described above. The chilled fluid coil  60  is supplied with chilled fluid through a chilled fluid loop  62 , comprising a supply line  64 , return lines  66  and  68 , and a valve  70 ; and terminating at the module container  10  with a pair of quick-connect couplings  72 . The chilled fluid directed through the loop  62  is supplied from a source (not shown) external to the module  100 . Preferably, the fluid in the loop  62  for such a cooling process is a water or glycol-water solution. However, the fluid in the loop  62  is not limited to a water or glycol-water solution and may be any pumpable fluid that is capable of accepting and releasing cooling through chilled fluid coils. Two sensors  74  and  76  on the supply line  64  and the return line  68 , respectively, detect and report the temperature of the fluid directed to and returning from the chilled fluid coil  60 . 
     A key feature of the modular air handling system  100  is the capability of automatically providing a variable volume and temperature of cooled air to facilities or equipment located external to the module  100 . The volume of air provided to the facility or equipment located in the space  18  through the supply duct  20  is controlled either by the variable volume control  38  of the blower  12  or by modulating the vane  42  as described above. 
     Temperature control of the facility serviced by the modular air handling system  100  is provided through the chilled fluid cooling coil  60  and the valve  70 . Under normal operating conditions, the entire flow of chilled fluid through the supply line  64  passes through the chilled fluid coil  60  and provides maximum cooling to the air passing through the return duct  24  to the blower  12 . If the temperature at the sensor  30  is cooler than a predetermined level, the valve  70  modulates, partially closing the supply of fluid into the valve  70  through the return line  66 . Simultaneously, the valve opens the orifice to the bypass line  78 . The effect of this valve modulation is that some of the chilled fluid in the supply line  64  is rerouted through the bypass line  78  and the valve  70  to the return line  68 , thereby bypassing the chilled fluid coil  60  and correspondingly reducing the capacity of the chilled fluid coil  60  to cool the air being drawn across it. The valve  70  can modulate to the point that the entire flow of fluid through the supply line  64  is directed through the bypass line  78 , and no flow is directed through the chilled fluid coil  60 . Under such a complete bypass condition, no cooling is provided by the chilled fluid coil  60 , and the air drawn through the return duct  24  does not pick up any cooling by the system. Should the temperature detected by the sensor  30  rise above the set temperature, the valve  70  will modulate, directing more flow through the chilled fluid coil  60 , until the desired temperature is detected by the sensor  30 . 
     The cooling function provided by the chilled fluid coil  60  is limited by the inventive system to avoid the risk of excessive dehumidification by condensation on the chilled fluid coil  60 . A minimum dew point to avoid excessive dehumidification is set for the sensor  34  as a function of the desired temperature and humidity for the space  18 . Should the temperature of the air exiting blower  12 , as detected by sensor  34 , fall below this set minimum dew point, the valve  70  will modulate to stop directing more flow through the chilled fluid  60  and to maintain the air temperature at sensor  34  above the minimum dew point. Under these circumstances where the minimum dew point has been reached, should the temperature at sensor  30  call for more cooling, the variable volume feature of the module  100  as discussed above is activated, with the volume of cooled air being propelled through supply duct  20  increasing until the temperature at sensor  30  is at the target temperature set for the space  18  serviced by the module  100 . As less cooling is required in the space  18 , the variable volume feature of the module  100  is the first to be deactivated, followed by the modulation of the valve  70  as described above to provide less flow of chilled fluid to the chilled fluid coil  60 . 
     Leads from each of the aforementioned sensors and controls may be directed to a control status panel (not shown) which may be located within the module  100 , external to the module container  10 , or both. The control status panel may be located at a site many miles from the module container  10 . The processing capacity to control each of the aforementioned features resides within the control status panel. The panel may merely display the temperature, flow, and pressure readings as detected by the various sensors. The panel may further indicate the operational status of each blower within the module container, such as displaying a green light for each component currently in operation. Additionally, the panel may contain lights and/or alarms that visually and/or audibly indicate an out-of-range condition as detected by the sensors and as compared against permissible range settings for each particular sensor. Upon detection of an out-of-range condition, the panel status light for the respective component may be changed from green to red, an audible alarm may be activated, and control circuitry may be activated to shut down the affected component. The various temperature and pressure control and alarm points may be reset by the user at the control status panel. 
     Industrial Applicability 
     In view of the foregoing, the present invention is advantageously applicable to a modular air handling system for providing a supply of cooled air to remotely situated resources, space, and equipment. The components for cooling the air and for propelling the cooled air to the space and equipment are secured within a transportable module container such that the entire structure can be swapped out should any component fail or should the cooling requirements of the remote space and equipment change. The components of the air handling system are also modular in that each component can be easily removed by non-technical personal and a replacement component easily and quickly plugged back in place so as to avoid or minimize any loss of cooling capacity. All connections of piping, ductwork, and power between the module container and its external environment are in the form of quick-connect couplings to facilitate the easy installation, removal, and replacement of the entire module. The modular plant is particularly useful in providing the cooled air required to air condition a computer room facility and to directly cool computer equipment. 
     Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims.