HEAT TRANSFER PROCESSES AND EQUIPMENT FOR INDUSTRIAL APPLICATIONS
Embodiments of the present invention permit the transfer of heat energy from one process fluid to another in an industrial process without the need for an energy field or centralized energy storage. Preferred embodiments include one or more heat transfer modules that draw heat from one process fluid into circulating refrigerant in an evaporator heat exchanger and supply that heat to a different process fluid in a condenser heat exchanger. In some embodiments, adjustments are made to one or more parameters of one or more process fluids to ensure the desired heat transfer is accomplished with the heat transfer module's compressor operating near optimum efficiency.
This application claims priority under 35 U.S.C. §119(e) to U.S. provisional application 61/313,517, filed Mar. 12, 2010, the entirety of which is hereby incorporated by reference herein.
BACKGROUNDIn industrial processes, process fluids are usually required for adding heat energy in some sub-processes and absorbing heat energy in other sub-processes. Warming process fluid so that it can supply heat energy in sub-processes typically requires natural gas or other independent heat source. Similarly, cooling process fluid so that it can absorb heat energy in sub-processes typically requires some type of independent refrigeration cycle.
Some systems aim to use some of the heat from one process fluid to another in an industrial process without independent heat energy sources or sinks, but such systems use a central energy storage mechanism. One such energy storage mechanism is an energy field. In a typical heat pump application (such as a geothermal heating/cooling system) the construction of the energy field can exceed 50% of the total project cost. In addition, energy fields require a significant amount of physical space that in many potential applications is simply not available. Furthermore, transferring energy into and out of the centralized storage system itself requires energy reducing the overall system efficiency.
SUMMARYEmbodiments of the present invention permit the transfer of heat energy from one process fluid to another in an industrial process without the need for an energy field or centralized energy storage. Preferred embodiments include one or more heat transfer modules that draw heat from one process fluid into circulating refrigerant in an evaporator heat exchanger and supply that heat to a different process fluid in a condenser heat exchanger. In some embodiments, adjustments are made to one or more parameters of one or more process fluids to ensure the desired heat transfer is accomplished with the heat transfer module's compressor operating near optimum efficiency.
Heat transfer modules used in connection with the present invention can be self-contained, engineered structures that include pumps, heat exchangers, compressors, instrumentation, valves and a control system in a unitized housing. Heat transfer modules can be deployed for the purpose of energy conservation in commercial, industrial, and utility applications. A common example of a heat transfer module is a heat pump unit. One or more heat transfer modules (and related process equipment) can be engineered, designed, installed, and/or maintained in a commercial, industrial or utility application.
The following figures are illustrative of particular embodiments of the present invention and therefore do not limit the scope of the invention. The figures are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present invention will hereinafter be described in conjunction with the appended photographs, wherein like numerals denote like elements.
The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical illustrations for implementing exemplary embodiments of the present invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements, and all other elements employ that which is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.
The refrigerant typically sheds heat to one fluid (e.g., liquid, vapor, gas, etc.) in the condenser heat exchanger 8 and takes on heat from a different fluid in the evaporator heat exchanger 4. As shown in
Heat transfer modules according to embodiments of the present invention that are used in industrial applications can have important differences from heat pumps used in HVAC applications. One key difference relates to how the two heat transfer modules are controlled. In HVAC applications, precise input and output parameters (e.g., temperature, flow rate, etc.) are generally less important than in industrial applications. Heat transfer modules for HVAC applications specifically endeavor to provide a heating or cooling effect for ambient conditioning. Minor variations in HVAC fluid parameters tend to have little effect on the overall comfort of the conditioned space. Moreover, because noticeable changes in the overall comfort of the conditioned space tend to occur slowly, heat transfer module operation adjustments can usually be made quickly enough to prevent any discomfort in the conditioned space. In contrast, if the heat transfer module does not precisely control warming/cooling fluid parameters in industrial applications, significant downstream consequences can result. Additionally, in HVAC applications, if the heat transfer module is cooling the conditioned space, what happens to the heat drawn out of the space is typically of little concern. Likewise, if the heat transfer module is heating the conditioned space, the effect on the environment from which the heat is drawn is typically of little concern. In contrast, when heat transfer module embodiments according to the present invention are used in industrial applications, they must usually be controlled to account for both the cooling fluid parameters and the warming fluid parameters because the fluids will be used in separate industrial sub-processes. For these and other reasons, precise control of fluid parameters is of greater importance for industrial heat transfer modules according to embodiments of the present invention than for HVAC heat transfer modules. Another key difference between heat transfer modules used in HVAC applications and heat transfer modules according to embodiments of the present invention that are used in industrial applications is that the metallurgy of one or more of the heat exchangers 4, 8 must often be modified to accommodate cooling or warming fluids in industrial applications because chemicals in the cooling or warming fluids may erode heat exchangers in standard heat transfer modules.
Although heat pump units are perhaps the most common heat transfer module used in connection with the present invention, other heat transfer modules can be used. For example, a reverse-acting screw compressor can replace an expansion valve in some embodiments. Such a compressor can be configured to achieve the same degree of expansion as would be achieved by the expansion valve. An advantage of this configuration, however, is that the reverse-acting screw compressor is able to convert the refrigerant expansion into mechanical energy. Such mechanical energy can be used to turn a generator, drive a pump, compress air, and so on. Other heat transfer modules, with different configurations of pumps, heat exchangers, compressors, instrumentation, valves, and/or controllers, can be used, depending on the type of industrial process and a variety of other factors.
As can be seen, the systems of
As noted above, eliminating the need for an energy field or centralized energy storage can provide several advantages. In a typical heat transfer module application (such as a geothermal heating/cooling system) the construction of the energy field can exceed 50% of the total project cost. In addition energy fields require a significant amount of physical space that in many potential applications is simply not available. Furthermore, transferring energy into and out of the centralized storage system itself requires energy reducing the overall system efficiency. Transferring heat energy from the cooling fluid to the warming fluid by way of the heat transfer module can result in very significant efficiency improvements.
The first and second heat transfer modules 2, 12 can receive warming and/or cooling fluids from the same or different sources and can provide warming and/or cooling fluids to the same or different industrial sub-processes. In
Many systems employ more than two heat transfer modules. In some systems, three, four, five, or more heat transfer modules can be employed. In such systems, some or all of the heat transfer modules can receive cooling fluid from the same source. In such systems, some or all of the heat transfer modules can receive warming fluid from the same source. In such systems, some or all of the heat transfer modules can provide cooling fluid to the same cooling industrial sub-process. In such systems, some or all of the heat transfer modules can provide warming fluid to the same warming industrial sub-process. In such systems, the various heat transfer modules can receive warming and/or cooling fluids from multiple sources. In such systems, the various heat transfer modules can provide warming and/or cooling fluids to multiple industrial sub-processes. Again, many combinations of input and output cooling/warming fluids are possible for systems employing multiple heat transfer modules.
In the system of
Bypassing the cooling tower, as shown in
Heat transfer modules discussed herein can be configured to work with a variety of cooling fluids and a variety of heating fluids. Some preferred heat transfer modules are configured to accommodate cooling fluid and warming fluid that are both liquid. Such heat transfer modules are often called liquid-to-liquid heat transfer modules. Examples include water-to-water, and so on. One example of a liquid-to-liquid heat transfer module is shown in
Additionally, and perhaps more importantly, embodiments of the present invention can substantially reduce the volume of water consumed in a conventional ethanol production facility. As is discussed in greater detail below, a fermentation vessel in an ethanol production facility produces large quantities of heat and is the subject of significant cooling efforts. If the fermentation vessel is not cooled properly, the performance of the fermentation enzymes is inhibited. In conventional ethanol plants, very large volumes of cooling water are circulated through a loop that includes a cooling tower and a fermentation vessel heat exchanger. The water draws in heat energy in the fermentation vessel heat exchanger and sheds that heat in the cooling tower. But as is mentioned above, considerable quantities of water are lost in cooling towers due to evaporation. In some systems, the volume of water flowing into the cooling tower is up to 1.3% greater than the volume of water flowing out of the cooling tower. While this may not sound like a large loss, when one considers that the average dry mill ethanol plant can have a flow rate of 55,000 gpm, small losses can add up quickly.
Additionally, reducing the evaporative loss at the cooling tower can have a cascading effect on water use throughout the ethanol production facility. The water that is lost through evaporation has to be “made-up” by supplying more water into the system. These additional quantities of water must be treated, filtered, softened, and otherwise conditioned to make them suitable for use in the process. Treatment methods for water entering a process plant can include:
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- Chemical treatment systems which require the purchase of various chemical agents to neutralize undesired water properties
- Filtration systems such as water softening, media filters, and reverse osmosis systems. These system require regeneration cycles and may still require chemical use (e.g., water softeners may utilize a sodium based brine as a regeneration agent). The regeneration water is typically discharged from the plant.
These illustrative treatment processes not only increase water use for the regeneration cycle, they also require that the regenerated water be discharged from the plant. The cascading effect of reducing evaporative loss dramatically reduces the plant discharge as well. The design parameters of a system capable of delivering 3.19 million BTUs of cooling at an ethanol facility would result in up to 309 million gallons of water bypassing the cooling tower each year. The cascading effect of eliminating the evaporative loss of this water will reduce well water use by over 10 million gallons annually and will reduce the facilities discharge by over 6.5 million gallons annually.
Thus, because many embodiments of the present invention involve cooling quantities of water with heat transfer modules, thereby bypassing the cooling tower and its associated evaporative loss, such embodiments of the present invention can provide very significant water savings for ethanol production facilities.
In the systems shown in
In many of the systems discussed herein, cooling fluid bound for a cooling industrial sub-process is routed directly through the evaporator heat exchanger of a heat transfer module, or warming fluid bound for a warming industrial sub-process is routed directly through the condenser heat exchanger of a heat transfer module. In many systems, however, the cooling/warming fluid need not be routed directly through the relevant heat exchanger of the heat transfer module. Instead, the cooling/warming fluid can be routed through a separate heat exchanger in which the cooling/warming fluid sheds/draws heat energy from a fluid that is in thermal communication with the relevant heat exchanger of the heat transfer module.
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- District Heating and Cooling Plants
- Commercial Laundry Facilities
- Central Plant Heating and Cooling Systems
- Hotels/Resorts
- Hospitals
- Institutional Facilities (Schools, Universities, Prisons)
- Dehumidification Systems
- Ice Arena
- Indoor Swimming Pool Areas
- Indoor Water Parks
- Merchant Power Utility
The system can include a heat transfer module refrigerant sensing mechanism that senses various attributes of the refrigerant during operation of the heat transfer module 202. The refrigerant sensing mechanism of
In preferred embodiments, the system can include a compressor controller 220 configured to ensure that the compressor 206 operates at as close to optimum efficiency as possible. When compressors operate near optimum efficiency, less energy input is required, and the compressors last longer and require less maintenance. In some embodiments, a key component in ensuring that the compressor 206 operates near optimum efficiency is the pressure differential of the refrigerant across the compressor 206 (i.e., the discharge pressure minus the suction pressure). If that pressure differential is too low or too high, the compressor 206 does not operate as efficiently and is at increased risk of breaking down. Based upon the application in which the compressor is applied, the compressor will have a “sweet spot” pressure differential range within which it operates most efficiently, and the compressor controller 220 aims to keep the compressor 206 within that range. The compressor controller 220 can be configured to receive the suction pressure value and the discharge pressure value from the refrigerant sensing mechanism. With that information, the compressor controller 220 can be configured to compare the suction pressure value to the discharge pressure value to determine an operational pressure differential.
As noted, the compressor controller 220 can be configured to maintain the operational pressure differential within a predetermined range. If the operational pressure differential is too high, the compressor controller 220 can take steps to reduce it. If the operational pressure differential is too low, the compressor controller 220 can take steps to increase it. The compressor controller 220 can take such steps by causing one or more of several variables to be adjusted. In some embodiments, the compressor controller 220 can cause the temperature and/or pressure and/or flow rate of a cooling fluid entering the evaporator heat exchanger 204 to be adjusted. In some embodiments, the compressor controller 220 can cause the temperature and/or pressure and/or flow rate of a warming fluid entering the condenser heat exchanger 208 to be adjusted. Some illustrative ways of causing such adjustments are discussed below.
The system of
In systems that involve a compressor controller 220, a warming fluid controller 224, and a cooling fluid controller 222, the three controllers can be programmed to limit the speed at which the output value adjusts. If the output values are all adjusted at the same rate of speed, each controller may seek to make adjustments on an almost continuous basis, never allowing the system to reach any kind of steady state. Cascading the controllers, or setting them to adjust their outputs at different rates of speed allows the lagging (slower-acting) controllers to react to adjustments made by the leading (faster-acting) controllers. For example, in preferred embodiments, one of the warming fluid controller 224 or the cooling fluid controller 222 can be configured to cause adjustment to the warming fluid inlet pump 228 or the cooling fluid inlet pump 226, respectively, at a first rate of speed (e.g., the output can adjust 1% in one second). The other of the warming fluid controller 224 or the cooling fluid controller 222 can be configured to cause adjustment to the warming fluid inlet pump 228 or the cooling fluid inlet pump 226, respectively, at a second rate of speed (e.g., the output can adjust 1% in two seconds), which is slower than the first rate of speed. The compressor controller 220 can be configured to communicate instructions to the warming fluid controller 224 and/or the cooling fluid controller 222 at a third rate of speed (e.g., the output can adjust 1% in three seconds), which is slower than the second rate of speed. It should be understood that other configurations may be employed for other systems and/or different controllers.
As noted, in some embodiments, the compressor controller 220 can be configured to cause the temperature of the cooling fluid and/or the temperature of the warming fluid to be adjusted. In many such embodiments, the cooling fluid inlet pump 226 and the warming fluid inlet pump 228 may have little or no ability to adjust the temperature of the respective fluids. In such embodiments, adjustments to the temperature can be made upstream of the fluid inlet pumps. The compressor controller 220 can be configured to cause the temperature of the cooling fluid and/or the temperature of the warming fluid to be adjusted by communicating instructions to one or more facility process controllers 230, 232. The facility process controllers 230, 232 can be responsible for controlling one or more processes at a facility into which one or more heat transfer modules are incorporated. In preferred embodiments, the facility process controllers 230, 232 can be configured to cause adjustment to one or more portions of the industrial process, thereby adjusting the temperature of the respective fluids before the reach the fluid inlet pumps.
Systems discussed herein that permit selective adjustment of the temperature and/or pressure and/or flow rate of one or more process fluids can provide a variety of advantages. For instance, such a system can account for situations in which one or more parameters of an input process fluid are dictated by the process itself and are not adjustable. For example, if the flow rate of the cooling fluid is fixed, the temperature and/or pressure of the cooling fluid can be adjusted in order to maintain the desired outputs. If the flow rate of the warming fluid is fixed, the temperature and/or pressure of the warming fluid can be adjusted in order to maintain the desired outputs. In addition, if both the cooling and warming fluid flow rates are fixed, the facility process controllers can be deployed to adjust to the desired outputs. In some embodiments, such selective adjustment can be an important factor in eliminating the need for central energy storage. Such selective adjustment can allow the ability to maintain process set point targets on both the warming fluid and cooling fluid sides of the system, as opposed to just one side or the other. Many systems such as those discussed herein allow optimization of energy consumption, with more performance output being provided per unit of energy input. Selective adjustment of multiple process fluid parameters can further enable the system to operate across the entire range of the performance window of the refrigerant, as opposed to using only part of the refrigerant performance range.
In a first aspect, the present invention involves a method of heating and cooling fluids for use in an industrial process. The method can include providing a heat transfer module that includes a condenser heat exchanger and a evaporator heat exchanger. The method can include circulating a refrigerant through the heat transfer module. The method can include circulating a cooling fluid through the evaporator heat exchanger, thereby removing heat from the cooling fluid and preparing the cooling fluid for a cooling industrial sub-process. The method can include circulating a warming fluid through the condenser heat exchanger, thereby adding heat to the warming fluid and preparing the warming fluid for a warming industrial sub-process. The method can include supplying the cooling fluid from an outlet of the evaporator heat exchanger to equipment for performing the cooling industrial sub-process. The method can include supplying the warming fluid from an outlet of the condenser heat exchanger to equipment for performing the warming industrial sub-process.
As alluded to elsewhere herein, the method of the first aspect can be used in connection with a variety of warming and cooling industrial sub-processes. For example, the cooling industrial sub-process can include (a) scrubbing carbon dioxide out of a fermentation vessel's waste stream in an ethanol production process; (b) cooling a fermentation vessel; (c) a food-related process; or (d) other cooling industrial sub-process. Also, for example, the warming industrial sub-process can include (a) warming water before it enters an ethanol cook system; (b) drying distilled grain in a dryer; or (c) other warming industrial sub-process.
In a second aspect, the present invention involves a method of transferring energy from one sub-process to another in an industrial process. The method can include providing a heat transfer module that includes a condenser heat exchanger and a evaporator heat exchanger. The method can include circulating a refrigerant through the heat transfer module. The method can include transferring energy (i) from a cooling fluid flowing toward a cooling industrial sub-process (ii) through the refrigerant via the evaporator heat exchanger and the condenser heat exchanger (iii) to a warming fluid flowing toward a warming industrial sub-process.
As alluded to elsewhere herein, the method of the second aspect can be used in connection with a variety of warming and cooling industrial sub-processes. For example, the cooling industrial sub-process can include (a) scrubbing carbon dioxide out of a fermentation vessel's waste stream in an ethanol production process; (b) cooling a fermentation vessel; (c) a food-related process; or (d) other cooling industrial sub-process. Also, for example, the warming industrial sub-process can include (a) warming water before it enters an ethanol cook system; (b) drying distilled grain in a dryer; or (c) other warming industrial sub-process.
In a third aspect, the present invention involves a method of minimizing an amount of water that is cooled via a cooling tower in an industrial process. The method can include providing a heat transfer module that includes a condenser heat exchanger and a evaporator heat exchanger. The method can include circulating a refrigerant through the heat transfer module. The method can include diverting a water quantity from a return line flowing toward the cooling tower from an industrial heat exchanger, the water quantity having been warmed in the industrial heat exchanger. The method can include circulating the water quantity through the evaporator heat exchanger, thereby removing heat from the water quantity and preparing the water quantity to return to the industrial heat exchanger. The method can include introducing the water quantity into a supply line flowing from the cooling tower toward the industrial heat exchanger, thereby bypassing the cooling tower. In some embodiments, circulating the first water quantity through the evaporator heat exchanger further includes transferring heat (i) from the water quantity (ii) through the refrigerant via the evaporator heat exchanger and the condenser heat exchanger (iii) to a warming fluid flowing toward a warming industrial sub-process. In some embodiments, the industrial heat exchanger comprises a fermentation vessel heat exchanger. Methods in accordance with this aspect of the invention can incorporate any of the features discussed elsewhere herein.
In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes can be made without departing from the scope of the invention. Thus, some of the features of preferred embodiments described herein are not necessarily included in preferred embodiments of the invention which are intended for alternative uses.
Claims
1. A method of heating and cooling fluids for use in an industrial process, the method comprising:
- (a) providing a first heat transfer module that includes a first condenser heat exchanger and a first evaporator heat exchanger;
- (b) circulating a first refrigerant through the first heat transfer module;
- (c) circulating a first cooling fluid through the first evaporator heat exchanger, thereby removing heat from the first cooling fluid and preparing the first cooling fluid for a first cooling industrial sub-process;
- (d) circulating a first warming fluid through the first condenser heat exchanger, thereby adding heat from the first refrigerant to the first warming fluid and preparing the first warming fluid for a first warming industrial sub-process;
- (e) supplying the first cooling fluid from an outlet of the first evaporator heat exchanger to equipment for performing the first cooling industrial sub-process; and
- (f) supplying the first warming fluid from an outlet of the first condenser heat exchanger to equipment for performing the first warming industrial sub-process.
2. The method of claim 1, further comprising:
- (g) providing a second heat transfer module that includes a second condenser heat exchanger and a second evaporator heat exchanger;
- (h) circulating a second refrigerant through the second heat transfer module;
- (i) circulating a second cooling fluid through the second evaporator heat exchanger, thereby removing heat from the second cooling fluid and preparing the second cooling fluid for the first cooling industrial sub-process; and
- (j) supplying the second cooling fluid from an outlet of the second evaporator heat exchanger to the equipment for performing the first cooling industrial sub-process.
3. The method of claim 2, further comprising:
- (k) circulating a second warming fluid through the second condenser heat exchanger, thereby adding heat from the second refrigerant to the second warming fluid and preparing the second warming fluid for the first warming industrial sub-process; and
- (l) supplying the second warming fluid from an outlet of the second condenser heat exchanger to the equipment for performing the first warming industrial sub-process.
4. The method of claim 2, further comprising:
- (k) circulating a second warming fluid through the second condenser heat exchanger, thereby adding heat from the second refrigerant to the second warming fluid and preparing the second warming fluid for a second warming industrial sub-process; and
- (l) supplying the second warming fluid from an outlet of the second condenser heat exchanger to the equipment for performing the second warming industrial sub-process.
5. The method of claim 4, wherein the first warming fluid is a liquid and the second warming fluid is a gas/vapor.
6. The method of claim 1, further comprising:
- (g) providing a second heat transfer module that includes a second condenser heat exchanger and a second evaporator heat exchanger;
- (h) circulating a second refrigerant through the second heat transfer module;
- (i) circulating a second cooling fluid through the second evaporator heat exchanger, thereby removing heat from the second cooling fluid and preparing the second cooling fluid for a second cooling industrial sub-process; and
- (j) supplying the second cooling fluid from an outlet of the second evaporator heat exchanger to equipment for performing the second cooling industrial sub-process.
7. The method of claim 6, further comprising:
- (k) circulating a second warming fluid through the second condenser heat exchanger, thereby adding heat from the second refrigerant to the second warming fluid and preparing the second warming fluid for a second warming industrial sub-process; and
- (l) supplying the second warming fluid from an outlet of the second condenser heat exchanger to the equipment for performing the second warming industrial sub-process.
8. The method of claim 6, further comprising:
- (k) circulating a second warming fluid through the second condenser heat exchanger, thereby adding heat from the second refrigerant to the second warming fluid and preparing the second warming fluid for the first warming industrial sub-process; and
- (l) supplying the second warming fluid from an outlet of the second condenser heat exchanger to the equipment for performing the first warming industrial sub-process.
9. The method of claim 6, wherein the first cooling fluid is a liquid and the second cooling fluid is a gas/vapor.
10. The method of claim 1, wherein the first cooling fluid and the first warming fluid are both liquid.
11. The method of claim 10, wherein the first cooling fluid and the first warming fluid are both water.
12. The method of claim 1, wherein the first cooling fluid is a liquid and the first warming fluid is a gas/vapor.
13. The method of claim 12, wherein the first cooling fluid is water and the first warming fluid is air.
14. The method of claim 1, wherein (i) the first heat transfer module includes a compressor and (ii) circulating the first refrigerant through the first heat transfer module includes maintaining an operational pressure differential across the compressor within a predetermined range.
15. The method of claim 14, wherein maintaining the operational pressure differential across the compressor within the predetermined range includes controlling one or more of the following:
- the temperature and/or pressure and/or flow rate of the first cooling fluid entering the first evaporator heat exchanger,
- the temperature and/or pressure and/or flow rate of the first warming fluid entering the first condenser heat exchanger.
16. The method of claim 14, wherein maintaining the operational pressure differential across the compressor within the predetermined range includes controlling one or more of the following:
- the pressure and/or flow rate of the first cooling fluid entering the first evaporator heat exchanger,
- the pressure and/or flow rate of the first warming fluid entering the first condenser heat exchanger.
17. A method of transferring energy from one process fluid to another in an industrial process, the method comprising:
- (a) providing a first heat transfer module that includes a first condenser heat exchanger and a first evaporator heat exchanger;
- (b) circulating a first refrigerant through the first heat transfer module; and
- (c) transferring energy (i) from a first cooling fluid flowing toward a first cooling industrial sub-process (ii) through the first refrigerant via the first evaporator heat exchanger and the first condenser heat exchanger (iii) to a first warming fluid flowing toward a first warming industrial sub-process.
18. The method of claim 17, further comprising:
- (d) providing a second heat transfer module that includes a second condenser heat exchanger and a second evaporator heat exchanger;
- (e) circulating a second refrigerant through the second heat transfer module; and
- (f) transferring energy (i) from a second cooling fluid flowing toward the first cooling industrial sub-process (ii) through the second refrigerant via the second evaporator heat exchanger and the second condenser heat exchanger (iii) to a second warming fluid flowing toward the first warming industrial sub-process.
19. The method of claim 17, further comprising:
- (d) providing a second heat transfer module that includes a second condenser heat exchanger and a second evaporator heat exchanger;
- (e) circulating a second refrigerant through the second heat transfer module; and
- (f) transferring energy (i) from a second cooling fluid flowing toward the first cooling industrial sub-process (ii) through the second refrigerant via the second evaporator heat exchanger and the second condenser heat exchanger (iii) to a second warming fluid flowing toward a second warming industrial sub-process.
20. The method of claim 19, wherein the first warming fluid is a liquid and the second warming fluid is a gas/vapor.
21. The method of claim 17, further comprising:
- (d) providing a second heat transfer module that includes a second condenser heat exchanger and a second evaporator heat exchanger;
- (e) circulating a second refrigerant through the second heat transfer module; and
- (f) transferring energy (i) from a second cooling fluid flowing toward a second cooling industrial sub-process (ii) through the second refrigerant via the second evaporator heat exchanger and the second condenser heat exchanger (iii) to a second warming fluid flowing toward a second warming industrial sub-process.
22. The method of claim 17, further comprising:
- (d) providing a second heat transfer module that includes a second condenser heat exchanger and a second evaporator heat exchanger;
- (e) circulating a second refrigerant through the second heat transfer module; and
- (f) transferring energy (i) from a second cooling fluid flowing toward a second cooling industrial sub-process (ii) through the second refrigerant via the second evaporator heat exchanger and the second condenser heat exchanger (iii) to a second warming fluid flowing toward the first warming industrial sub-process.
23. The method of claim 22, wherein the first cooling fluid is a liquid and the second cooling fluid is a gas/vapor.
24. The method of claim 17, wherein the first cooling fluid and the first warming fluid are both liquid.
25. The method of claim 24, wherein the first cooling fluid and the first warming fluid are both water.
26. The method of claim 17, wherein the first cooling fluid is a liquid and the first warming fluid is a gas/vapor.
27. The method of claim 26, wherein the first cooling fluid is water and the first warming fluid is air.
28. The method of claim 17, wherein (i) the first heat transfer module includes a compressor and (ii) circulating the first refrigerant through the first heat transfer module includes maintaining an operational pressure differential across the compressor within a predetermined range.
29. The method of claim 28, wherein maintaining the operational pressure differential across the compressor within the predetermined range includes controlling one or more of the following:
- the temperature and/or pressure and/or flow rate of the first cooling fluid entering the first evaporator heat exchanger,
- the temperature and/or pressure and/or flow rate of the first warming fluid entering the first condenser heat exchanger.
30. The method of claim 28, wherein maintaining the operational pressure differential across the compressor within the predetermined range includes controlling one or more of the following:
- the pressure and/or flow rate of the first cooling fluid entering the first evaporator heat exchanger,
- the pressure and/or flow rate of the first warming fluid entering the first condenser heat exchanger.
31. A system for transferring energy from one process fluid to another in an industrial process, comprising:
- (a) a heat transfer module that includes a compressor, a condenser heat exchanger, and an evaporator heat exchanger;
- (b) a refrigerant sensing mechanism configured to regularly measure a suction pressure value and a discharge pressure value for the compressor during operation of the heat transfer module; and
- (c) a compressor controller configured to (i) receive the suction pressure value and the discharge pressure value from the refrigerant sensing mechanism, (ii) compare the suction pressure value to the discharge pressure value to determine an operational pressure differential, (iii) maintain the operational pressure differential within a predetermined range by causing one or more of the following to be adjusted:
- the temperature and/or pressure and/or flow rate of a cooling fluid entering the evaporator heat exchanger,
- the temperature and/or pressure and/or flow rate of a warming fluid entering the condenser heat exchanger.
32. The system of claim 31, further comprising (d) a cooling fluid controller, wherein the compressor controller is configured to cause the pressure and/or the flow rate of the cooling fluid to be adjusted by communicating instructions to the cooling fluid controller, which is configured to cause adjustment to a cooling fluid inlet pump.
33. The system of claim 31, further comprising (d) a warming fluid controller, wherein the compressor controller is configured to cause the pressure and/or the flow rate of the warming fluid to be adjusted by communicating instructions to the warming fluid controller, which is configured to cause adjustment to a warming fluid inlet pump.
34. The system of claim 33, further comprising (e) a cooling fluid controller, wherein the compressor controller is configured to cause the pressure and/or the flow rate of the cooling fluid to be adjusted by communicating instructions to the cooling fluid controller, which is configured to cause adjustment to a cooling fluid inlet pump.
35. The system of claim 34, wherein
- one of the warming fluid controller or the cooling fluid controller is configured to cause adjustment to the warming fluid inlet pump or the cooling fluid inlet pump, respectively, at a first rate of speed;
- the other of the warming fluid controller or the cooling fluid controller is configured to cause adjustment to the warming fluid inlet pump or the cooling fluid inlet pump, respectively, at a second rate of speed, which is slower than the first rate of speed; and
- the compressor controller is configured to communicate instructions to the warming fluid controller and/or the cooling fluid controller at a third rate of speed, which is slower than the second regular interval.
36. The system of claim 31, wherein the compressor controller is configured to cause the temperature of the cooling fluid and/or the temperature of the warming fluid to be adjusted by communicating instructions to a system controller, which is configured to cause adjustment to one or more portions of the industrial process.
37. The system of claim 31, wherein the heat transfer module further includes an expansion valve.
Type: Application
Filed: Mar 14, 2011
Publication Date: Oct 6, 2011
Inventors: Jack W. Allen (Minneapolis, MN), Hans B. Alwin (Saint Michael, MN)
Application Number: 13/047,463
International Classification: F25B 49/02 (20060101); F25B 7/00 (20060101); F25B 1/00 (20060101);