Title:
Heat extraction system for cooling power transformer
Kind Code:
A1


Abstract:
A cooling system for controlling including a heat exchanger defining a first interior space and a second interior space in thermal exchange with one another. First interior space is in fluid communication with the power transformer. A refrigeration system is in fluid communication with second interior space and provides a chillant to second interior space. A transformer cooling fluid circulates through and between first interior space and the power transformer. An energy source is operably coupled to the refrigeration system and supplies heat energy to energize the refrigeration system. In operation, thermal energy is absorbed by transformer cooling fluid in the power transformer to thereby cool the power transformer. In the heat exchanger thermal energy is removed from transformer cooling fluid in first interior space and is absorbed by chillant in second interior space to thereby cool the transformer cooling fluid.



Inventors:
Longardner, Robert L. (Indianapolis, IN, US)
Application Number:
10/887289
Publication Date:
12/23/2004
Filing Date:
07/08/2004
Assignee:
LONGARDNER ROBERT L.
Primary Class:
International Classes:
F02C6/18; F02C7/141; F02C7/143; F25B27/02; (IPC1-7): F25B27/00
View Patent Images:



Primary Examiner:
JIANG, CHEN WEN
Attorney, Agent or Firm:
FAEGRE DRINKER BIDDLE & REATH LLP (INDIANAPOLIS, IN, US)
Claims:

What is claimed is:



1. A cooling system for controlling the internal temperature of a power transformer, the cooling system comprising: a heat exchanger defining a first interior space and a second interior space, said first interior space in a thermal exchange relationship with said second interior space, said first interior space in fluid communication with the power transformer; a refrigeration system in fluid communication with said second interior space and providing a chillant to said second interior space, said chillant circulating through and between said second interior space and said refrigeration system; a transformer cooling fluid circulating through and between said first interior space and the power transformer; and an energy source operably coupled to said refrigeration system and supplying heat energy to energize said refrigeration system, said energy source including at least one of an air breathing heat engine (ABHE) and a steam turbine, wherein during operation of the cooling system thermal energy is absorbed by said transformer cooling fluid in the power transformer to thereby cool the power transformer, and wherein in said heat exchanger thermal energy is removed from said transformer cooling fluid in said first interior space and is absorbed by said chillant in said second interior space to thereby cool said transformer cooling fluid.

2. The cooling system of claim 1 wherein said refrigeration system is an absorption chiller.

3. The system of claim 2 wherein said absorption chiller employs recovered heat energy from said energy source to energize a staged process of concentration, condensation, evaporation and absorption to provide said chillant.

4. The system of claim 1, wherein said transformer cooling fluid is a liquid.

5. The system of claim 4 wherein said transformer cooling fluid comprises an oil.

6. The system of claim 1 wherein one of said first and second interior spaces is defined by an elongate tube, the other of said first and second interior spaces is defined by a hollow coil disposed within said elongate tube.

7. The system of claim 1 wherein said first interior space is defined by a first coil and the second interior space is defined by a second coil, said first and second coils in heat exchange with one another.

8. The system of claim 1 further comprising a temperature control valve operably connected to said power transformer, said temperature control valve sensing the temperature of said power transformer and controlling the communication of said transformer cooling fluid from said power transformer to said first interior space based on the sensed temperature.

9. The system of claim 1 wherein said energy source includes an air breathing heat engine (ABHE), said ABHE including: a gas conditioner defining a gas conditioning area, said gas conditioner includes a conditioning heat exchanger and a sensible heat exchanger, each of said conditioning heat exchanger and sensible heat exchanger being disposed in said gas conditioner area; each of said conditioning heat exchanger and sensible heat exchanger being in fluid communication with said refrigeration system and receiving said chillant from said refrigeration system; a combustor defining an inlet port and a discharge port, said inlet port in fluid communication with said gas conditioner area of said gas conditioner; a waste recovery unit operably coupled to said discharge port of said combustor; a post-combustion heat exchanger operably coupled to said waste recovery unit and in fluid communication with said refrigerant system, wherein during operation of said ABHE air is received into said gas conditioning area, thermal energy is transferred from said air to said chillant in said conditioning heat exchanger and said sensible heat exchanger to thereby condition said air, said combustor receiving said conditioned air and producing an exhaust gas, said exhaust gas containing thermal heat energy, said waste recovery unit receiving exhaust gas, said post-combustion heat exchanger recovering thermal heat energy in the exhaust gas and communicating said heat energy to said refrigeration system.

10. The system of claim 9 wherein said refrigeration system includes an absorption chiller, said absorption chiller employing the recovered heat energy to energize a staged process of concentration, condensation, evaporation and absorption to produce said chillant.

11. A cooling system for improving the efficiency of the manufacture and distribution of electricity, the system comprising: a power transformer; a refrigeration system; a heat dissipation device including a heat exchanger, said heat exchanger defining a first interior space and a second interior space, said first interior space in thermal exchange with said second interior space; a refrigeration circuit through which a chillant circulates, said refrigeration circuit having operably coupled thereto said refrigeration system and said second interior space, wherein during operation of the cooling system heat is removed from said chillant in said refrigeration system and heat is added to said chillant in said heat exchanger; a transformer cooling circuit through which a transformer cooling fluid circulates, said transformer cooling circuit having operably coupled thereto said power transformer and said first interior space, wherein during operation of the cooling system heat is absorbed by said transformer cooling fluid in said power transformer and heat is transferred from said transformer cooling fluid to said chillant in said heat exchanger; a heat energy generating component, said heat energy generating component generating heat energy and said refrigeration system utilizing the heat energy to energize a process for circulating and removing heat from said chillant.

12. The system of claim 11 further comprising a temperature control valve operably connected to transformer cooling circuit, said temperature control valve sensing the temperature of said power transformer and controlling the circulation of said transformer cooling fluid through said transformer cooling circuit.

13. The system of claim 11 wherein said process for circulating and removing heat from said chillant includes staged processes of concentration, condensation, evaporation and absorption.

14. The system of claim 11, wherein said heat generating component includes at least one of an air breathing heat engine (ABHE) and a steam turbine.

15. The system of claim 111 wherein said refrigeration system includes an absorption chiller, said chiller employing the heat energy to energize a staged process of concentration, condensation, evaporation and absorption to provide the chillant.

16. The system of claim 11, wherein one of said first and second interior spaces is defined by an elongate tube, the other of said first and second interior space is defined by a hollow coil disposed within said elongate tube.

17. The system of claim 11, wherein said transformer cooling fluid is a liquid.

18. The system of claim 11, wherein said heat energy generating component comprises an air breathing heat engine (ABHE), said ABHE includes: a combustor; a waste recovery unit operably coupled to said combustor; and a post-combustion heat exchanger operably coupled to said waste recovery unit and in fluid communication with said refrigerant system, wherein during operation of said ABHE said combustor produces an exhaust gas, said exhaust gas containing heat energy, said waste recovery unit receiving said exhaust gas, said post-combustion heat exchanger recovering heat energy from the exhaust gas and communicating said heat energy to said refrigeration system.

19. The system of claim 18 wherein said ABHE further includes a shaft operably driven by said combustor, and a power generator drivingly connected to said shaft to actuate said power generator.

20. The system of claim 19 further comprising a generator cooling circuit through which a generator cooling fluid circulates, said generator cooling circuit having operably coupled thereto said generator and said refrigeration system, wherein during operation of the cooling system said generator cooling fluid absorbs heat in said generator to cool said generator and heat is removed from said generator cooling fluid in said refrigeration system.

21. The system of claim 19 further comprising: a generator heat exchanger defining a first interior path and a second interior path, said first interior path in heat exchange with said second interior path; a generator cooling circuit through which a generator cooling fluid circulates, said generator cooling circuit having operably coupled thereto said generator and said first interior path; and a generator refrigeration circuit through which the chillant circulates, said second refrigeration circuit having operably coupled thereto said refrigeration system and said second interior path, wherein during operation of the cooling system heat is absorbed by said generator cooling fluid in said generator to cool said generator and heat is transferred from said generator cooling fluid to said chillant in said generator heat exchanger.

22. The system of claim 11 wherein said heat energy generating component includes a steam turbine operably coupled to said refrigeration system, said steam turbine generating hot water, said hot water containing heat energy, said steam turbine communicating said hot water and said heat energy to said refrigeration system, said refrigeration system employing the heat energy to energize a staged process of concentration, condensation, evaporation and absorption to produce said chillant.

23. A method for controlling the internal temperature of one or more components of a system for generating and distributing electricity, the method comprising the steps of: circulating a transformer cooling fluid through a transformer cooling circuit, the transformer cooling circuit having operably coupled thereto a power transformer and a heat exchanger, whereby heat is absorbed by the transformer cooling fluid in the power transformer and heat is extracted from the transformer cooling fluid in said heat exchanger; and circulating a chillant through a refrigeration circuit, the refrigeration circuit having operably coupled thereto the heat exchanger and a refrigeration system, whereby heat is extracted from the chillant in the refrigeration system and heat is absorbed by the chillant in the heat exchanger.

24. The method of claim 23 further comprising the step of: generating heat energy to energize the refrigeration system using an air breathing heat engine (ABHE), the step of generating heat energy using the ABHE including the steps of: producing an exhaust gas containing heat energy by combustion; discharging the exhaust gas into a waste heat recovery unit; and recovering the heat energy contained in the exhaust gas by circulating a working fluid through an energy recovery circuit, the energy recovery circuit operably coupled to the refrigeration system and a second heat exchanger, the second heat exchanger operably coupled to the waste heat recovery unit, whereby heat energy is transferred from the exhaust gas to the working fluid in the second heat exchanger and the working fluid is circulated to the refrigeration system wherein said refrigeration system employs the heat energy to energize a staged process of concentration, condensation, evaporation and absorption.

25. The method of claim 24 wherein the working fluid comprises the chillant.

26. The method of claim 23 further comprising the step of generating heat energy to energize the refrigeration system using a steam turbine, the step of generating heat energy using the steam turbine including the steps of: generating hot water using the steam turbine, the hot water containing heat energy; communicating the hot water and the heat energy contained therein to the refrigeration system; and the refrigeration system employing the heat energy to energize a staged process of concentration, condensation, evaporation and absorption.

27. The method of claim 23 further comprising the step of regulating the circulation of transformer cooling fluid through the transformer cooling circuit by sensing the temperature of the power transformer, communicating the sensed temperature to a temperature control valve, the temperature control valve operably coupled to transformer cooling circuit, the temperature control valve restricting the circulation of the transformer cooling fluid when the sensed temperature is below a pre-determined value and permitting the circulation of the transformer cooling fluid when the sensed temperature is above a pre-determined value.

28. The method of claim 23, wherein the refrigeration system includes an absorption chiller.

29. The method of claim 23 further comprising the steps of: circulating a generator cooling fluid through a generator cooling circuit, the generator cooling circuit having operably coupled thereto a generator and a generator heat exchanger, whereby heat is absorbed by the generator cooling fluid in the generator and heat is extracted from the generator cooling fluid in the generator heat exchanger; and circulating the chillant through a generator refrigeration circuit, the generator refrigeration circuit having operably coupled thereto the generator heat exchanger and the refrigeration system, whereby heat is extracted from the chillant in the refrigeration system and heat is transferred from the generator cooling fluid to the chillant in the generator heat exchanger.

Description:

PRIORITY REFERENCE

[0001] This application is a continuation-in-part application claiming priority under 35 U.S.C. §120 to pending U.S. patent application Ser. No. 10/351,712 filed Jan. 27, 2003.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention.

[0003] The present invention relates to power transformers, which may be step-up or step-down transformers.

[0004] 2. Description of the Related Art

[0005] The manufacturing of electricity begins at the power plant, where a turbine engine driven by fuels such as natural gas, oil, and coal, is used to produce electricity. The turbine engine is operably connected to a generator via a shaft. The generator includes a large magnet surrounded by coiled copper wire. The turbine causes the magnet to rotate inside the coils, which generates electricity by creating a current in each coil. Such turbine engines are commonly in the form of either steam turbines, which burn the fuel in a boiler and produce high pressure steam, or air breathing heat engines (ABHE), which burn the fuel in a combustor and produce an exhaust gas.

[0006] From the generator, the power is “stepped up” to a very high voltage by a large power transformer for more economical transmission over long distances to different substations. A substation may include an electrical apparatus that generally transforms the voltage to lower levels. From the substations the power then travels to other distribution transformers. These distribution transformers reduce the voltage to the 120-volt and 240-volt levels required for appliances and equipment. From the distribution transformers, the power is channeled to distribution panels and home circuit breakers. It is at this point that the power is divided up into several circuits that serve different loads.

[0007] Generally, transformers are highly efficient and can deliver practically the full power received. However, transformer losses, typically in the form of heat, can reduce transformer efficiency, resulting in a reduction of load capacity and service. Examples of transformer losses affected by heat and load which can be metered are: copper loss, hysteresis loss, eddy current loss, iron loss, no-load loss, and impedance loss. In addition, heat from transformer losses can degrade the insulation of the transformer, thus reducing the life of the transformer. Heat losses can similarly occur in the generator, thereby reducing the efficiency of the generator and reducing the life of the generator.

[0008] It is prudent to manage transformer and generator losses by preventing overheating. Known systems address the overheat problem of power transformer by using fans or other cooling mechanisms such as cooling oil baths. These systems commonly utilize external sources of energy, and therefore, can reduce efficiency and increase operating costs. Accordingly, a need remains for an efficient system for controlling the internal temperature of the transformer and/or generator.

SUMMARY OF THE INVENTION

[0009] The present invention provides a cooling system for controlling the internal temperature of the components of a power manufacturing system. In one embodiment the cooling system is adapted to cool a power transformer. The cooling system includes a heat exchanger defining a first interior space and a second interior space. The first interior space is in a thermal exchange relationship with the second interior space and the first interior space is in fluid communication with the power transformer. A refrigeration system is in fluid communication with the second interior space and provides a chillant to the second interior space. The chillant circulates through and between the second interior space and the refrigeration system. A transformer cooling fluid circulates through and between the first interior space and the power transformer. An energy source is operably coupled to the refrigeration system and supplies heat energy to energize the refrigeration system. The energy source includes an air breathing heat engine (ABHE) or a steam turbine. During operation of the cooling system, thermal energy is absorbed by the transformer cooling fluid in the power transformer to thereby cool the power transformer. In the heat exchanger thermal energy is removed from the transformer cooling fluid in the first interior space and is absorbed by the chillant in the second interior space to thereby cool the transformer cooling fluid.

[0010] In another embodiment, the present invention provides a cooling system for improving the efficiency of the manufacture and distribution of electricity. The cooling system includes a power transformer, a refrigeration system, a heat dissipation device, a refrigeration circuit through which a chillant circulates, a transformer cooling circuit through which a transformer cooling fluid circulates, and a heat energy generating component. The heat dissipation device includes a heat exchanger defining a first interior space and a second interior space. The first interior space is in thermal exchange with the second interior space. The refrigeration circuit is operably coupled to the refrigeration system and the second interior space, wherein during operation of the cooling system heat is removed from the chillant in the refrigeration system and heat is added to the chillant in the heat exchanger. The transformer cooling circuit is operably coupled to the power transformer and the first interior space, wherein during operation of the cooling system heat is absorbed by the transformer cooling fluid in the power transformer and heat is transferred from the transformer cooling fluid to the chillant in the heat exchanger. The heat generating component generates heat energy and the refrigeration system utilizes the heat energy to energize a process for circulating and removing heat from the chillant.

[0011] The present invention also provides a method for controlling the internal temperature of one or more components of a system for generating and distributing electricity. The method includes the steps of circulating a transformer cooling fluid through a transformer cooling circuit, the transformer cooling circuit having operably coupled thereto a power transformer and a heat exchanger, whereby heat is absorbed by the transformer cooling fluid in the power transformer and heat is extracted from the transformer cooling fluid in the heat exchanger; and circulating a chillant through a refrigeration circuit, the refrigeration circuit having operably coupled thereto the heat exchanger and a refrigeration system, whereby heat is extracted from the chillant in the refrigeration system and heat is absorbed by the chillant in the heat exchanger.

[0012] One advantage of the invention is that it provides the method for cooling the inner working of a transformer for all atmospheric and load conditions while other directed chillant is conditioning the ambient air stream to the ABHE which magnifies the amount of electrical energy for retail by 20-30% when ambient temperatures are around 95° F. (35° C.) compared to the through-put for turbine ISO or transformer nameplate rating. The chillant provides the means to protect the transformer against the damage of temperature rise due to the heat gain in the inherent losses.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0014] FIG. 1 is a diagram showing an embodiment of a power transformer cooling system according to one embodiment of the present invention;

[0015] FIG. 2 is a diagram of a power transformer cooling system according to another embodiment of the present invention, wherein the energy source is an ABHE;

[0016] FIG. 3 is a diagram of a power transformer cooling system according to yet another embodiment of the present invention, wherein the energy source is a steam turbine; and

[0017] FIG. 4 is a diagram of a power transformer/generator cooling system according to another embodiment of the present invention.

[0018] Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize the teachings.

[0020] Referring now to FIGS. 1 and 2, cooling system 10 for improving the efficiency of the manufacture and distribution of electricity is illustrated. Cooling system 10 generally includes power transformer 20, heat exchanger 31, and refrigeration system 60. Power transformer 20 may be any conventional transformer used to step up or step down the voltage electrical power. Power transformer 20 generates heat through transformation losses such as heat due to resistance flow of current, heat due to hysteresis, heat due to eddy currents, and heat due to no-load. The efficiency of transformer 20 can be calculated in terms of energy units (kilowatt hour, Kwh):

Efficiency=Output/Input=Output (Kwh)/[Output (Kwh)+Heat loss (Kwh)]

[0021] The voltage regulation of transformer 20 is the percentage change in the output voltage from no-load to full-load. [% Regulation=(no-load voltage−load voltage)×100/load voltage)]. Ideally, there should be no change in the transformer's output voltage from no-load to full-load. In such a case, the voltage regulation is 0%. To get the best performance out of a transformer, it is necessary to have the lowest possible voltage regulation.

[0022] Power transformer 20 may be any commercially available transformer, such as any one of the common classes of transformers listed in TABLE 1. 1

TABLE 1
The most common classes of transformer
THE MOST COMMON CLASSES OF TRANSFORMER
CLASSCOOLING METHOD
OAOUTSIDE-AIRSELF-COOLED (BY CONVECTION)
OA/FAOUTSIDE-AIR/FAN-AIRSELF-COOLED OR FAN COOLED
OA/FA/FAOUTSIDE-AIR W/2 FAN COOLING SETSSELF-COOLED/FAN COOLED
OA/FA/FOAOUTSIDE-AIR/FAN-AIR/FORCED (PUMPED) OILSELF-COOLED, FAN COOLED PUMPED OIL
FOAFORCED OIL/FAN COOLEDPUMPED OIL WITH FANS
AAAIR-AIR DRY TYPE (OR CAST INSULATION)SELF COOLED (BY CONVECTION)
AA/FAAIR-AIR/FAN-AIR IN DRY TYPESELF-COOLED WITH FANS

[0023] Power transformer 20 may have various built-in overload capabilities, and existing cooling method as shown in TABLE 1. The existing cooling method requires a supply of external energy. For example, a cooling fan requires a connection to an outside electrical source. The existing cooling method may be replaced or complemented by system 10 of the present invention.

[0024] Turning back to FIGS. 1 and 2, heat exchanger 31 has a shell-and-tube design including elongated tube 29 defining first interior space 32, and hollow coil 33 disposed within first interior space 32. Although heat exchanger 31 is illustrated as having a shell-and-tube design, it should be understood that heat exchanger 31 may be of any known heat exchanger design including, for example, a dual heat transfer coil having a tube within tube construction. Tube 29 defines tube inlet 36 and tube outlet 37, each of which are in fluid communication with first interior space 32. Hollow coil 33 extends along the length of tube 29 and defines second interior space (not shown). Coil 33 also defines inlet coil connection 41 at one end and outlet coil connection 40 at the opposite end, each of which communicate with second interior space (not shown).

[0025] Cooling system 10 further includes a transformer cooling circuit 26 through which a transformer cooling fluid circulates. Transformer cooling fluid may be any fluid capable of absorbing the heat of power transformer 20. Suitable transformer cooling fluids include oil, such as dielectric oils. Transformer cooling circuit 26 includes medium line 24, which fluidly connects power transformer 20 to heat exchanger 31. More specifically, medium line 24 includes first end 34 fluidly connected to power transformer 20, and second end 35 fluidly connected via tube inlet 36 to interior space 32 of tube 29. Transformer cooling circuit 26 also includes medium return line 25, which fluidly connects power transformer 20 to heat exchanger 31. Medium return line 25 includes a first end 43 in fluid communication with interior space 32 of heat exchanger 31 through tube outlet 37, and second end 44 in fluid communication with power transformer 20.

[0026] Cooling system 10 also includes a refrigeration circuit 27 through which a chillant circulates. The chillant may be any conventional chillant or refrigerant useful in refrigeration systems, especially those chillants useful in absorption chillers, such as those described in U.S. Pat. No. 4,936,109. Refrigeration circuit 27 includes first chillant line 52 and first chillant return line 53, each of which communicate fluid between heat exchanger 31 and refrigeration system 60. First chillant line 52 has first end 55, operably connected to and in fluid communication with refrigeration system 60, and second end 54 connected to and in fluid communication with second interior space of hollow coil 33 via inlet coil connection 41. First chillant return line 53 has first end 57 connected to and in fluid communication with second interior space of hollow coil 33 via outlet coil connection 40, and second end 56 operably connected to and in fluid communication with refrigeration system 60.

[0027] Refrigeration system 60 may be any suitable absorption chiller or refrigeration generator available in the market. Examples of absorption chillers and refrigeration generators that can be used in cooling system 10 are described in U.S. Pat. No. 4,936,109, the disclosure of which is hereby fully incorporated by reference. Generally, an absorption chiller or a refrigeration generator employs heat energy from an energy source to energize a staged process of concentration, condensation, evaporation and absorption to provide a chillant for cooling purposes. The chillant may be in a fluid form, such as water, gas, oil, or mixture thereof.

[0028] As depicted in FIGS. 1 and 2, in operation, refrigeration system 60 produces a cool chillant that is transferred through first chillant line 52 and into second interior space of hollow coil 33 via inlet coil connection 41. The initial temperature of this cool chillant may be about 50° F. (10° C.). At the same time, transformer cooling fluid circulates through power transformer 20, during which heat energy from transformer losses is absorbed by the transformer cooling fluid in power transformer 20. As a result, power transformer 20 is cooled and the transformer cooling fluid is heated.

[0029] The heated transformer cooling fluid flows from power transformer 20 through medium line 24 to heat exchanger 31. At heat exchanger 31 the transformer cooling fluid enters interior space 32 of tube 29 through tube inlet 36. While in tube 29, heat energy is transferred from transformer cooling fluid to the cool chillant in second interior space of hollow coil 33 by a heat transfer process, such as conduction, convection and radiation. This heat transfer (heat exchange) results in cooling the transformer cooling fluid and heating the chillant. As a result of the heat exchange, the temperature of heated chillant may reach a about 80° F. (29.4° C.). The resulting cool transformer cooling fluid then exits tube 29 via tube outlet 37 and enters medium return line 25, which returns the cool transformer cooling fluid back to power transformer 20 for further cooling transformer 20 and the process (circulation) is repeated. Meanwhile, the heated chillant exits hollow coil 33 through outlet coil connection 40 and is returned via chillant return line 53 to refrigeration system 60 wherein the chillant is cooled and recirculated through refrigeration circuit 27.

[0030] It should also be understood that heat exchanger 31 may have any design capable of placing the chillant and cooling fluid in heat exchange with one another. In addition, heat exchanger 31 may be adapted so that the chillant flows through the first interior space 32 of tube 29 and the cooling fluid flows through coil 33.

[0031] In another embodiment of the present invention illustrated in FIGS. 1 and 2, first end 34 of first medium line 24 is connected to power transformer 20 through valve 50, which is adapted to permit the flow of transformer cooling fluid through medium line 24 when the internal temperature of power transformer 20 reaches a predetermined temperature, and restrict the flow when the internal temperature of power transformer 20 drops below the predetermined temperature. When the temperature of heated medium reaches a pre-determined temperature, valve 50 opens to release heated medium into medium line 24.

[0032] In another embodiment of the present invention, shown particularly in FIG. 2, the energy source for refrigeration system 60 of cooling system 10 is an air breathing heat engine (ABHE) 70, such as that disclosed in U.S. Pat. No. 6,082,094, which is hereby incorporated by reference. ABHE 70 generally includes air conditioner 72, combustion turbine 100, and waste heat recovery unit 111. Air conditioner 72 defines air conditioner area 75 and includes air intake vents 73, which communicate air to air condition area 75. Disposed within air condition area 75 is air conditioning coil 74 and sensible cooling coil 78. Air conditioning coil 74 and sensible cooling coil 78 are in fluid communication with, and receive cool chillant from, refrigeration system 60 via second refrigeration circuit 80.

[0033] Second refrigeration circuit 80 includes second chillant feed line 82, which is fluidly joined at one end to chillant line 52 of first refrigeration circuit 27, thereby fluidly communicating with refrigeration system 60. The opposite end of second chillant feed line 82 is split into chillant feed sub-lines 82a, 82b, which are fluidly connected to the inlet ends of air conditioning coil 74 and sensible cooling coil 78, respectively. Second refrigeration circuit 80 also includes second chillant return line 83, which is fluidly connected at one end to chillant return line 53 of first refrigeration circuit 27, thereby fluidly communicating with refrigeration system 60. The opposite end of second chillant return line 83 is split into chillant return sub-lines 83a, 83b, which are fluidly connected to the outlet ends of air conditioning coil 74 and sensible cooling coil 78, respectively. Air conditioner 72 may also include de-misters 77 disposed within air conditioning area 75 for removing additional moisture from the air in air conditioning area 75.

[0034] In an alternative embodiment (not shown), second chillant line 82 may be in direct communication with refrigeration system 60, without first joining first chillant line 52. Similarly, second chillant return line 83 may be in direct communication with refrigeration system 60, without first joining first chillant return line 53. In this specific embodiment, second chillant line 82 extends directly from refrigeration system 60. Likewise, second chillant return line 83 extends directly to refrigeration system 60.

[0035] Combustion turbine 100 includes intake port 101, turbine 102, and exhaust port 108. Intake port 101 is in fluid communication with air conditioning area 75 to receive conditioned intake air. Turbine 102 is in fluid communication with intake port 101 and exhaust port 108. Turbine 102 is operably coupled to shaft 103, which, in turn, is operably coupled to generator 106. Waste heat recovery unit 111 includes exhaust port 110, which is fluidly coupled to exhaust port 108 to receive exhaust gas produced by combustion turbine 100.

[0036] Waste heat recovery unit 111 also includes exhaust stack or flue 109 and a post combustion heat exchanger 112, which is in heat exchange with the interior of exhaust stack 109. Heat exchanger 112 may include any number of heat exchange coils. As shown in FIG. 3, heat exchanger 112 has a top coil 114 and bottom coil 115. Each of top and bottom coils 114, 115 are fluidly coupled to refrigeration system 60 via an energy recovery circuit 117 through which a working fluid is circulated. The working fluid may be any fluid capable of absorbing and releasing energy. In one embodiment, the chillant flowing in the first and second refrigeration circuits serves as the working fluid. Energy recovery circuit 117 includes chillant supply line 116 and chillant return line 118, each of which are operably coupled at one end to refrigeration system 60. The opposite end of chillant supply line 116 splits into sub-lines 116a, 116b, which are fluidly coupled to the inlet end of top and bottom heat exchange coils 114, 115, respectively. The opposite end of chillant return line 118 splits into sub-lines 118a, 118b, which are fluidly coupled to the outlet ends of top and bottom heat exchange coils 114, 115, respectively.

[0037] In operation, air is drawn into conditioning area 75 through air intake vents 73 and flows through air conditioning coil 74, whereby heat energy in the air is transferred by a heat exchange process to the chillant contained in air conditioning coil 74, thereby cooling and conditioning the air. The conditioned air then passes de-misters 77 whereby moisture is removed from the air to further condition the air. The conditioned air then flows through sensible cooling coil 78, whereby additional heat energy is transferred from the air to the chillant in sensible cooling coil 78, thereby further cooling the air and heating the chillant. The heated chillant from conditioning coil 74 and sensible cooling coil 78 flows to second return chillant line 83 via sub-lines 83a, 83b, respectively. Second return chillant line 83 transfers the chillant to return line 52 which, in turn, returns the chillant to refrigeration system 60. Refrigeration system 60 cools the chillant and circulates cool chillant through second refrigeration circuit 80. In one example, chillant 62 has a temperature of 42° F. (5.6° C.) when it is supplied to sensible cooling coil 78 and air conditioning coil 74, whereas, heated chillant returning to refrigeration system 60 may have a temperature of 52° F. (11° C.).

[0038] Meanwhile, conditioned air from air conditioning area 75 flows through intake port 101 to turbine 102 where it is mixed with injected fuel and is ignited resulting in a combustion force that drives shaft 103. The rotation of shaft 103 actuates generator 106 to produce electricity. The combustion of the fuel and air produces a hot exhaust gas containing energy in the form of the heat of combustion. The hot exhaust gas, produced as a result of the combustion, is discharged from turbine 102 via exhaust port 108 and enters waste heat recovery unit 111 via exhaust port 110. In waste heat recovery unit 111, the hot exhaust gas flows up exhaust stack or flue 113, wherein it enters into heat exchange with combustion heat exchanger 112 positioned within flue 113. The exhaust gas flows through bottom chillant coil 115 and top chillant coil 114, wherein the heat energy contained in the exhaust gas is absorbed by the working fluid in top chillant coil 114 and bottom chillant coil 115.

[0039] Heat energy from exhaust gas 107 in waste recovery unit 111 is captured in the working fluid or chillant within top chillant coil 114 and bottom chillant coil 115. The resulting heated working fluid exits top and bottom coils 114, 115 via sub-lines 118a, 118b, respectively. The heated working fluid then flows through chillant return line 118 to refrigeration system 60. The heat energy stored in the working fluid is used by refrigeration system 60 to produce cool chillant, as described above and in U.S. Pat. No. 4,936,109.

[0040] In a specific embodiment of the present invention (not shown), the air breathing heat engine may further include an acoustic enclosure, as described in U.S. Pat. No. 6,082,094, the disclosure of which is herein incorporated by reference. Refrigeration system 60 may supply chillant for ventilating the acoustic enclosure via appropriate chillant supply line connection (not shown) or through an additional heat exchanger placed within the acoustic enclosure, or as described in U.S. Pat. No. 6,082,094.

[0041] In another embodiment shown in FIG. 3, refrigeration system 60 is powered by steam turbine system 120, which is connected to and in fluid communication with refrigeration 60 via an energy recovery circuit 217. Refrigeration system 60 is connected to power transformer 20 in the same fashion, as shown in FIG. 1. Generally, steam turbine system 120 releases heat energy in the form of hot water, which is transferred to refrigeration system 60 for use in the production of cool chillant.

[0042] Steam turbine system 120 may be any known steam turbine. For example, as depicted in FIG. 3, steam turbine system 120 includes steam turbine engine 121 and steam condenser 122 in communication with turbine engine 121. Turbine engine 121 includes shaft 125 connected to power generator 126, or other machine or equipment that is operable using power from an engine. Steam turbine engine 121 receives condensate and/or steam from a source, which can be a boiler of a compatible capacity. The condensed steam enters steam turbine 121 through steam inlet pipe 128 and expands in turbine engine 123, with an output of power driving shaft 125 to actuate power generator 126. After complete expansion, the expanded steam flows to steam condenser 122 from turbine engine 123 through an appropriate exhaust steam casing (not shown), and is condensed to hot water having a temperature of about 210° F. (98.9° C.). Expanded steam or hot water can be returned to the steam source or the boiler through return pipe 129. Hot water containing heat energy, may also flow through first hot water pipe 132 from condenser 122 to refrigeration system 60. Refrigeration system 60 uses the heat energy for the production of chillant for cooling power transformer 20 (see FIG. 1).

[0043] Additional hot water or working fluid may flow from condenser 122 through second hot water pipe 134 to hot water heater 140, which is connected to steam turbine 121. It is also possible to have excess steam from turbine engine 123 to flow through steam pipe 136 to supply heat to hot water heater 140. Hot water flowing through refrigeration system 60, wherein a portion of heat is extracted from hot water for the production of chillant, may be returned to hot water heater 140 through third hot water pipe 142. Output hot water 150 from hot water heater 140 can be distributed for various heating purposes.

[0044] In a specific embodiment (not shown), condenser may contain a heat exchanger that can capture heat energy from condensing the steam. The captured heat energy can then be transferred to refrigeration system 60, similar to what has been discussed above as relating to the ABHE.

[0045] Further, it is possible to combine the embodiments shown in FIGS. 2 and 3, so that both steam turbine 121 and air breathing heat engine 100 are components of the same system. Both turbine 121 and air breathing heat engine 100 may produce heat energy that together can be supplied to refrigeration system 60. In addition, if air breathing heat engine 100 produces excess heat, the heat energy may be used to heat the water in the connected hot water heater 140. For particular applications and circumstances, the amount of generated heat apportioned to refrigeration system and hot water heater 140 may be adjusted.

[0046] In yet another embodiment, the cooling system may be adapted to cool the generator in addition to, or instead of, the power transformer. Turning to FIG. 4, for example, cooling system 10 is adapted to cool generator 106 in addition to power transformer 20 (FIG. 2). Cooling system 10 includes generator heat exchanger 172, generator refrigeration circuit 170 through which the chillant circulates, and generator cooling circuit 180 through which a generator cooling fluid circulates. Generator cooling fluid may be any fluid capable of absorbing and releasing heat, such as known refrigerants, water, oil, and gas. Generator heat exchanger 172 is similar to heat exchanger 31 (FIGS. 1 and 2) and includes tube 174 defining first interior path 175, and hollow coil 176 disposed within first interior path 175 and defining a second interior path (not shown). Generator refrigeration circuit 170 fluidly connects refrigeration system 60 to generator heat exchanger 172 and includes chillant feed line 178 and chillant return line 179. Chillant feed line 178 is fluidly coupled at one end to chillant line 52, which fluidly connects line 178 to refrigeration system 60. The opposite end of chillant feed line 178 is fluidly coupled to the inlet end of the second interior path of hollow coil 176. Chillant return line 179 is fluidly coupled to the outlet end of the second interior path of hollow coil 176. The opposite end is fluidly coupled to return line 53 which fluidly connects to refrigeration system 60. Generator cooling circuit 180 fluidly connects generator 106 to generator heat exchanger 172 and includes cooling fluid feed line 182 and cooling fluid return line 184. Cooling fluid feed line 182 is fluidly coupled to generator 106 at one end and to the inlet of first interior path 175 of tube 174 at the opposite end.

[0047] In operation, refrigeration system 60 supplies cool chillant to chillant feed line 178 via chillant line 52. The cool chillant flows through feed line 178 and enters the second interior path of hollow coil 176. In the meantime, generator cooling fluid flowing in generator 106 absorbs the heat of generator 106 to thereby cool generator 106 and heat the generator cooling fluid. The heated generator cooling fluid exits generator 106 and enters fluid feed line 182. The heated cooling fluid flows through feed line 182 to generator heat exchanger 172 where it enters first interior path 175 of tube 174. In heat exchanger 172 heat is transferred from the cooling fluid in first interior path 175 of tube 174 to the chillant in hollow coil 17, thereby cooling the cooling fluid and heating the chillant. The resulting heated chillant exits tube 174 and flows via return line 179 to chillant return line 53. The heated chillant then flows via return line 53 to refrigeration system 60 where the heat of the chillant is removed to provide cool chillant, and the process is repeated. Meanwhile, the cooled cooling fluid exits tube 174 and enters fluid return line 184, which returns the cooled cooling fluid to generator 106. The cooled cooling fluid absorbs additional heat from generator 106 and the process is repeated.

[0048] As in the case with the power transformer 20, a valve (not shown) may be operably coupled to generator cooling circuit 180 to control the flow of cooling fluid in response to the temperature of the generator 106 and/or cooling fluid in generator 106.

[0049] In another embodiment (not shown), the generator may be cooled directly by chillant thereby eliminating the need for the generator heat exchanger and generator cooling fluid. In this embodiment, chillant would circulate through and directly between the refrigeration system and the generator.

[0050] It should also be understood that heat exchanger 172 may have any design capable of placing the chillant and cooling fluid in heat exchange with one another. In addition, heat exchanger 172 may be adapted so that the chillant flows through the first interior path 175 of tube 174 and the cooling fluid flows through coil 176.

[0051] It is one advantage of the present invention to protect power transformer 20 and/or the generator by keeping power transformer 20 at a suitable temperature, regardless of the ambient temperature. It is another advantage of the present invention to use one on-line refrigeration system 60 to produce chillant for cooling different components of a power generation system. Refrigeration system 60 takes advantage of heat energy that is released from internal sources within the system, and minimizes external energy requirements.

[0052] While the present invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.