US20160123206A1

US20160123206A1 - Waste heat reclamation system, method for reclamation of waste heat, and system and method for using waste heat

Info

Publication number: US20160123206A1
Application number: US14/531,088
Authority: US
Inventors: David E. Hopple
Original assignee: Boeing Co
Current assignee: Boeing Co
Priority date: 2014-11-03
Filing date: 2014-11-03
Publication date: 2016-05-05

Abstract

A system for reclamation of waste heat from a heat load is disclosed and described. The system comprises a heat exchanger coupled to a heat load for capturing waste heat from the heat load; and a heat sink coupled to the heat exchanger to disperse the waste heat. The system further comprises a device coupled to the heat sink for utilizing energy from the waste heat dispersed by the heat sink. A method for reclamation of waste heat from a heat load and utilization of the waste heat are also disclosed and described.

Description

FIELD

The present disclosure relates to a waste heat reclamation system and a method for reclamation of waste heat and heat transfer. The present disclosure also relates to a system and method for using energy from the waste heat and producing electricity from the waste heat.

BACKGROUND

A power lab, or any building with, for example, manufacturing or testing machinery or other devices, typically produces energy in the form of heat as a byproduct of normal operations. These building typically have a water-based cooling loop. In addition to buildings with manufacturing and testing facilities, this is also true of at least some office buildings, which produce excess heat and utilize large air handlers for air conditioning. Rather than capturing and utilizing this energy/heat, the heat is typically discharged out of the building to the environment surrounding the building.
FIG. 1 is an illustration of a current system 11. A building 10 includes one or more heat loads 12. Examples of possible heat loads 12 are a power lab, manufacturing or testing machinery and devices, an air-conditioning system, or a heat exchanger. An example of a power lab is an electrical systems lab utilizing water-cooled load banks. Each heat load 12 produces energy in the form of heat. The heat is captured by a liquid flowing in one or more pipe(s) 14 which are coupled to heat load 12. These pipes 14 typically contain water with chemicals added to control corrosion and biological contamination. As the liquid in the pipe 14 passes by the heat load 12, the liquid is heated by the excess heat produced by heat load 12.
The heat captured in the liquid in pipe 14 is pumped to a heat exchanger 18, such as for example, a chiller or an air conditioner. The heat exchanger 18 can be in the same building as the heat load 12 or in a separate building, such as at 16. Heat exchanger 18 removes the heat from the heated liquid in pipe 14 and recirculates cooled liquid back to heat load 12 in pipe(s) 20. Pipe 20 is coupled to heat load 12 to cool the heat loads and remove the excess heat from heat load 12 to pipe 14 as discussed supra. Pipe(s) 14, heat exchanger 18, and pipe(s) 20 form a cooling loop 22 for heat load 12. However, as the heat removed from pipe 14 by heat exchanger 18 cannot remain in the building, it is released to the outside of the building as waste heat 24. Waste heat 24, for example, is currently consumed as in a toaster or resistance heating element, and fans blow the heat out of the building.
Even if one were able to capture the waste heat, the production of waste heat in the heat loads is variable and non-continuous depending on test conditions and the operation and/or application of the power lab. For example, when testing airplane electrical systems, and components, test conditions are dependent upon the airplane test profile. For instance, for a simulated flight profile such as flying in icing conditions, load banks are used to simulate resistance loads for wing icing. These loads generate heat that needs to be removed. The amount of heat generated will vary dependent upon the flight profile, i.e., altitude and temperature. Therefore, there is a dynamic changing of load and heat output. Similarly, building heat loads are dependent and vary based upon outside temperature, amount of sunshine, and number of lights, people, computers, and other heat generating sources. As a result, heat loads removed by air conditioning systems in buildings also are variable and non-continuous depending on conditions. In contrast, a power company desires to receive a stable power supply which is non-variable and continuous. A power company usually has no practical utilization for a variable or non-continuous power supply.

SUMMARY

The disclosed embodiments include a system for reclamation of waste heat produced by a heat load. A further embodiment is directed to a system for producing energy and electricity from the reclamation of waste heat. Another embodiment is directed to a method of reclamation of waste heat from a heat load. Still another embodiment is directed to a method for using the energy and electricity from the reclamation of waste heat.
In an embodiment of the present disclosure, in a system for reclamation of waste heat, a heat sink is coupled to heat exchanger which is coupled to a heat load. Waste heat is captured from the heat load and conveyed to the heat exchanger in a fluid. The heat exchanger removes the waste heat from the fluid and transports cooled fluid to the heat load. The removed waste heat in the heat exchanger is then transported to a heat sink in another fluid. The heat sink then removes the waste heat from the fluid and disperses the removed heat to a device for further use of the waste heat.
According to one embodiment, a system for reclamation of waste heat from a heat load comprises a heat exchanger coupled to a heat load for capturing waste heat from the heat load and a heat sink coupled to the heat exchanger to disperse the captured waste heat for further use. In one aspect, a first pipe is coupled to the heat load and the heat exchanger in a loop to capture the waste heat from the heat load and transport the waste heat to the heat exchanger, and another pipe is coupled to the heat exchanger and the heat sink in a second loop to transport the waste heat from the heat exchanger to the heat sink. In a further aspect, the first pipe contains a fluid for absorbing the waste heat from the heat load and transporting the waste heat to the heat exchanger. The heat exchanger removes the waste heat from the fluid and cools the fluid in the first pipe and cooled fluid is sent to the heat load via the loop in the first pipe. In yet a further aspect, the other pipe also contains a fluid for removing the waste heat from the heat exchanger and transporting the waste heat to the heat sink. The heat sink removes the waste heat from the fluid and cools the fluid in the other pipe and cooled fluid is sent to the heat exchanger via the second loop. In still a further aspect, the heat sink is coupled to a device for utilizing energy from the waste heat removed by the heat sink for further use. In another aspect, the energy from the waste heat is converted into electricity for further use.
According to another embodiment, a system for producing electricity using waste heat from a heat load comprises a heat exchanger coupled to a heat load for capturing waste heat from the heat load, a heat sink coupled to the heat exchanger to collect and disperse the waste heat, a closed loop coupled to the heat sink, and a device that produces electricity coupled to the closed loop. The captured waste heat from the heat sink is dispersed into the closed loop and transported to the device that produces electricity and powers the device to produce electricity. In one aspect, the closed loop contains a refrigerant, and the refrigerant is heated when contacted by the captured waste heat in the heat sink. The heated refrigerant is transported to the device that produces electricity and powers the device. In a further aspect, the temperature of the refrigerant in the closed loop is maintained within a constant temperature range.
In another embodiment, a method for reclamation of waste heat from a heat load comprises capturing in a fluid the waste heat from the heat load, removing in a heat exchanger the waste heat from the fluid and transporting the removed waste heat to a heat sink, and removing in a heat sink the waste heat from the heat exchanger and dispersing the removed waste heat to a device for further use of the waste heat. A further aspect includes converting the dispersed waste heat from the heat sink into energy and utilizing the energy produced from the waste heat.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an existing heat load producing waste heat and system for removing heat from the heat load.

FIG. 2 is an illustration of an embodiment of the present disclosure.

FIG. 3 is an illustration of a heat exchanger of the present disclosure.

FIG. 4 is an illustration of a heat sink of the present disclosure.

FIG. 5 is an illustration of a waste heat reclamation system of the present disclosure.

DETAILED DESCRIPTION

The disclosed embodiments of the present disclosure relate to a system and a method for reclamation of waste heat and additionally a system and a method for producing energy or electricity using waste heat. The present disclosure also relates to a method for heat transfer of the waste heat. The systems and methods described herein capture the waste heat from the heat load and provide means for utilizing the waste heat. Further, the systems and methods described herein provide continuous energy from variable and non-continuous waste heat and, in a further embodiment, reduce safety concerns associated with use of steam, which is often produced within the pipe removing waste heat from the heat loads.
In an embodiment of the present disclosure, the system for reclamation of waste heat from a heat load includes a heat exchanger coupled to a heat load for capturing the waste heat and a heat sink coupled to the heat exchanger to disperse the waste heat from the heat exchanger for further use.
FIGS. 2 and 5 are embodiments of the present disclosure. A system 100 for heat transfer and waste heat reclamation is shown in FIGS. 2 and 5. System 100 is associated with one or more buildings 110 and one or more heat loads or power labs 112 included in building 110. Building 110 in FIG. 2 is similar to building 10 in FIG. 1, and one or more heat loads or power labs 112 are similar to heat loads/power labs 12 in FIG. 1. In one embodiment, all the elements of this system are located in one building 110. In an alternative embodiment, the elements of the system can be located throughout multiple buildings, such as, for example, some of the elements of the system can be located in a second building at 116 as illustrated in FIG. 5.
Similar to FIG. 1, system 100 includes one or more first pipes 114, a heat exchanger 118, and one or more second pipes 120. An example of heat exchanger 118 is a chiller or an air conditioner. Another example of heat exchanger 118 is a plate heat exchanger. First pipe 114 is coupled to heat load 112 and heat exchanger 118, and second pipe 120 is also coupled to heat exchanger 118 and heat load 112. In one embodiment, first pipe 114 and second pipe 120 are connected in a closed loop 122 through heat exchanger 118 and coupled to heat load 112. In a further embodiment illustrated in FIG. 3, heat exchanger 118 includes at least one closed loop 122, and in yet a further embodiment, a second closed loop 124. First closed loop 122 includes first pipe 114 and second pipe 120. Second closed loop 124 includes a third pipe 126 and a fourth pipe 128.
In contrast to system 10 shown in FIG. 1, system 100 further includes a heat sink 130. Heat sink 130 provides a means to capture the waste heat, rather than releasing the waste heat to the outside of the building, and disperse the captured waste heat to another device for further use. An example of a heat sink is a cooling water storage receptacle or a water holding tank. In a further embodiment illustrated in FIGS. 2 and 4, in system 100, third pipe 126 from second closed loop 124 is coupled to heat sink 130. In an embodiment illustrated in FIG. 4, third pipe 126 from heat exchanger 118 flows through heat sink 130. A third closed loop 132 of pipes is also located in heat sink 130. In one embodiment, third loop 132 includes fifth pipe 134 and sixth pipe 138. In a further embodiment, shown in FIG. 5, a circulation pump 127 is coupled to third pipe 126.
In a further embodiment, as shown for example in FIGS. 2 and 5, third loop 132 of pipes is coupled to a device 136 via fifth pipe 134 and sixth pipe 138. One example of a device 136 that could be coupled to loop 132 is a turbine for producing electricity. One example of such a turbine is a micro turbine. A micro turbine is used by small businesses to generate electricity for individual use and typically uses heat from a small boiler in a heating system, as opposed to a large turbine used by a power company. Instead of a boiler, using the system of the present disclosure, the micro turbine utilizes waste heat from heat sink 130 as a power source to spin the micro turbine.
In another embodiment, device 136 is coupled to a generator 140 for producing electricity. The electricity is then available for use in buildings 110 and/or 116 or other surrounding buildings. Alternatively, generator 140 is then connected to power grid 142 to provide electricity for a power company.
During operation of system 100, a fluid flows in first pipe(s) 114. Examples of this fluid include water, such as discussed supra for pipe 14, a vapor, or a refrigerant. The fluid flowing in first pipe 114 captures and absorbs the heat produced by heat load 112, and the fluid then transports the heat away from heat load 112 to heat exchanger 118 when the heated fluid flows from the heat load 112 to the heat exchanger 118. Heat exchanger 118 removes the heat from the fluid in first pipe 114 and transports cooled fluid back to heat load 112 through one or more second pipe(s) 120. In one embodiment, where first pipe 114 and second pipe 120 are connected in a closed loop 122, the fluid flows in the closed loop through heat exchanger 118 and heat load 112.
As illustrated in FIG. 3, wherein heat exchanger 118 includes two closed loops 122, 124, first closed loop 122 brings heated fluid from first pipe 114 into heat exchanger 118 where the heat exchanger transfers that heat to second closed loop 124. Thereafter, cooled fluid leaves heat exchanger 118 through second pipe 120, and heated fluid leaves heat exchanger 118 through third pipe 126, which is part of second closed loop 124.
In an embodiment illustrated in FIGS. 2 and 4, fluid heated from the waste heat in third pipe 126 is transported to heat sink 130. In one embodiment, where the heat sink 130 is a cooling water storage receptacle, the water in the holding tank is at 170-200° F. (77-82° C.), which will yield a 100° F. (metric) temperature difference above ambient. The temperature is controlled by, for example, at least one thermocouple and a heat pump.
In an embodiment illustrated in FIG. 4, third pipe 126 containing the heated fluid from heat exchanger 118 flows through heat sink 130. Third pipe 126 transfers heat to a third loop 132 of pipes in heat sink 130. Loop 132 also contains a fluid. In one embodiment, the fluid is a refrigerant. In a further embodiment, the fluid is R-410. The transfer of heat from third pipe 126 to loop 132 causes the fluid in loop 132 to be heated. Thereafter, cooled fluid leaves heat sink 130 through fourth pipe 128 to heat exchanger 118 as part of loop 124, and heated fluid leaves heat sink 130 though fifth pipe 134 as part of loop 132.
In one embodiment, the temperature of heat sink 130 and the fluid in loop 132 are below the vapor transition temperature for producing steam, which alleviates the need for steam safety precautions. This avoids the special safety requirements and expense of a steam system. Further, a heat sink 130 of the present disclosure, that is holding hot water and not steam, can be added to a current system, such as for example, system 11 shown in FIG. 1, for removing waste heat with only small modifications to the current system.
In a further embodiment, heat sink 130 is large enough to handle fluctuations in the production of waste heat from heat load 112 and maintain a constant temperature range in the heat sink. In one example, the heat sink is sized based upon mean heat load, as well as material/chemicals added to the heat sink. In another example, the heat sink is sized based on load characteristics, i.e., dynamic or static loads. As a further example, the heat sink is sized using industry standard calculations for heat load or HVAC systems. The ability to handle fluctuations in the production of waste heat is especially advantageous for handling waste heat from buildings, which produce more waste heat during the day then at night. In addition, HVAC heat loads from buildings are dependent upon numerous factors, such as for example, ambient temperature, number of building occupants, number and wattage of heat producing appliances/computers, amount of sunshine, window tinting, type of indoor lighting, air flow, humidity, and number of doors/volume of usage. These factors vary continuously. The resulting loads from these factors cause output of waste heat from the HVAC system to fluctuate. It is advantageous to alleviate these fluctuations in waste heat in the heat sink 130 and provide a non-varying continuous supply to device 136.
In a further embodiment, as shown for example in FIGS. 2 and 5, loop 132 is coupled to device 136, such as for example, a turbine, via fifth pipe 134 and sixth pipe 138. The heated refrigerant in fifth pipe 134 causes the turbine to turn. In one embodiment, the turbine can be sized as stages, with, for example, smaller turbines used in steps to remove the heat provided to the turbine from the heat sink. In another embodiment, the refrigerant in loop 132 absorbs heat from heat sink 130, which causes the pressure of the refrigerant in loop 132 to increase. The high pressure refrigerant travels via fifth pipe 134 to device 136 where the high pressure refrigerant transfers energy to the turbine, which causes the turbine to generate energy. In one example, the transfer of energy is through use of a nozzle which allows the refrigerant to flash into a vapor/stream and transfer energy to the micro turbine. This refrigerant is then cooled when the energy is transferred to device 136. The cooled refrigerant is then pumped back into the water heat sink 130. In a further embodiment, device 136 is connected to a generator 140. The generator 140 produces electricity from rotation within the turbine produced by the vapor in fifth pipe 134. The electricity from generator 140 is then provided to a power grid 142 when the electricity can be used by a power company. Alternatively, the electricity can be used in buildings 112 and/or 116 or surrounding buildings.
In a further embodiment, the temperature of the refrigerant in loop 132 is within a constant temperature range. The constant temperature range is maintained by, for example, one or more thermocouples and a heat pump, to maintain the heat within heat sink 130 at the constant temperature range. The constant temperature in heat sink 130 maintains the refrigerant in loop 132 in the constant temperature range. In a further embodiment, the constant temperature of the refrigerant is maintained below the boiling point/steam transition temperature.
In an alternative embodiment, the constant temperature of the refrigerant in loop 132 is above the refrigerant vapor temperature so as to produce consistent vapor within fifth pipe 134. This constant source of vapor will continuously move the turbine and produce continuous energy and electricity.
In a further embodiment, the waste heat reclamation system of the present disclosure is used with multiple turbines, multiple buildings, multiple heat sinks, and multiple pipes.
This description has been offered for illustrative purposes only and is not intended to limit the invention of this application. Although described with respect to specific embodiments, the details of these embodiments are not to be construed as limitations.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

Claims

What is claimed is:

1. A system for reclamation of waste heat from a heat load, the system comprising:

a heat exchanger coupled to a heat load for capturing waste heat from the heat load; and

a heat sink coupled to the heat exchanger to disperse the captured waste heat for further use.

2. The system of claim 1 further comprising:

a first loop coupled to the heat load and the heat exchanger to capture the waste heat from the heat load and transport the waste heat to the heat exchanger; and

a second loop coupled to the heat exchanger and the heat sink to transport the waste heat from the heat exchanger to the heat sink.

3. The system of claim 2 wherein the first loop contains a fluid for absorbing the waste heat from the heat load and transporting the waste heat to the heat exchanger, and

wherein the heat exchanger removes the waste heat from the fluid and cools the fluid in the first loop and cooled fluid is sent to the heat load via the first loop.

4. The system of claim 2 wherein the second loop contains a fluid for removing the waste heat from the heat exchanger and transporting the waste heat to the heat sink, and

wherein the heat sink removes the waste heat from the fluid and cools the fluid in the second loop and cooled fluid is sent to the heat exchanger via the second loop.

5. The system of claim 1 wherein a loop containing fluid is operably connected to the heat sink, and

wherein the fluid is heated when contacted by the waste heat in the heat sink and the heated fluid is transported to a device for utilizing energy produced by the heated fluid.

6. The system of claim 5 wherein the device is a turbine for producing electricity.

7. The system of claim 6 further comprising a generator coupled to the turbine to produce electricity

8. The system of claim 1 wherein the heat sink is a cooling water storage receptacle.

9. A system for producing electricity using waste heat from a heat load, the system comprising:

a heat exchanger coupled to a heat load for capturing waste heat from the heat load;

a heat sink coupled to the heat exchanger to collect and disperse the waste heat;

a closed loop coupled to the heat sink; and

a device that produces electricity coupled to the closed loop,

wherein the captured waste heat from the heat sink is dispersed into the closed loop and transported to the device that produces electricity and powers the device to produce electricity.

10. The system of claim 9 wherein the closed loop contains a refrigerant and the refrigerant is heated when contacted by waste heat in the heat sink; and

wherein the heated refrigerant is transported to the device and powers the device.

11. The system of claim 10 wherein a temperature of the refrigerant in the closed loop is maintained within a constant temperature range.

12. The system of claim 11 wherein the temperature of the refrigerant in the closed loop is below a refrigerant vapor temperature.

13. The system of claim 11 wherein the temperature of the refrigerant in the closed loop is above a refrigerant vapor temperature.

14. A method for reclamation of waste heat from a heat load, the method comprising:

capturing in a fluid the waste heat from the heat load;

removing in a heat exchanger the waste heat from the fluid and transporting the removed waste heat to a heat sink; and

removing in a heat sink the waste heat from the heat exchanger and dispersing the removed waste heat to a device for further use of the waste heat.

15. The method of claim 14 further comprising:

converting the dispersed waste heat from the heat sink into energy and utilizing the energy produced from the waste heat.

16. The method of claim 14 wherein the removed waste heat in the heat sink is captured in a refrigerant and the refrigerant with the waste heat is transported to the device for further use of the waste heat.

17. The method of claim 16 wherein a temperature of the refrigerant is maintained within a constant temperature range.

18. The method of claim 17 wherein the temperature of the refrigerant is below a refrigerant vapor temperature.

19. The method of claim 17 wherein the temperature of the refrigerant is above a refrigerant vapor temperature.