Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D20/00—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00
  • F28D20/0034—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 using liquid heat storage material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
  • H01M8/04067—Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins
  • H01M8/04074—Heat exchange unit structures specially adapted for fuel cell
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D20/00—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00
  • F28D2020/006—Heat storage systems not otherwise provided for
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2250/00—Fuel cells for particular applications; Specific features of fuel cell system
  • H01M2250/40—Combination of fuel cells with other energy production systems
  • H01M2250/405—Cogeneration of heat or hot water
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02B90/10—Applications of fuel cells in buildings
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/14—Thermal energy storage
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/30—Hydrogen technology
  • Y02E60/50—Fuel cells

Definitions

• the present invention relates to a fuel cell system generating electrical energy by an electrochemical reaction of hydrogen and oxygen, and more particularly, to a heat recovery apparatus of a fuel cell system, which supplies heat generated from various electric power generation elements including a fuel cell stack to hot water or to heating circulating water by effectively recovering the heat.
• a fuel cell is an electric power generation apparatus that generates electrical energy by an oxidation reaction of hydrogen and a reduction reaction of oxygen.
• the fuel cell is classified into types such as a polymer electrolyte membrane fuel cell and a direct methanol fuel cell.
• the polymer electrolyte membrane fuel cell is a fuel cell using a polymer membrane, having hydrogen ion exchange characteristics, as an electrolyte and generates electrical energy by inducing an electrochemical reaction by means of fuel containing hydrogen and air containing oxygen.
• a fuel cell system using the polymer electrolyte fuel cell has the following schematic structure. That is, the fuel cell system may include a fuel cell power generating apparatus for generating the electrical energy and a heat recovery apparatus for supplying waste heat generated from the fuel cell power generating apparatus to a site where heat is in demand by recovering the waste heat as constituent members.
• the fuel cell power generating apparatus includes a fuel cell stack for generating DC power by the electrochemical reaction of hydrogen and oxygen, a reformer for supplying reformed gas having sufficient hydrogen to the fuel cell stack by reforming a hydrocarbon-based power generation material such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG), an air supply device for supplying oxygen required in the fuel cell stack, a power converter that converts the DC power generated by the fuel cell stack into AC power, and various BOPs (Balance of Plants) and controllers that are required for starting and stopping the constituent members and maintaining power generation.
• a hydrocarbon-based power generation material such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG)
• LNG liquefied natural gas
• LPG liquefied petroleum gas
• the heat recovery apparatus of the fuel cell system has the following schematic configuration by referring to information disclosed in Korean Patent Nos. 0418459 and 0740542. That is, the heat recovery apparatus of the fuel cell system according to the related art includes a heat storage tank for storing waste heat recovered from the fuel cell power generating apparatus and a device for supplying the waste heat stored in the heat storage tank to hot water or to heating circulating water.
• the heat recovery apparatus of the fuel cell system is configured to recover waste heat generated from various system constituent members such as the fuel cell stack and the fuel treatment device in the fuel cell power generating apparatus.
• the fuel cell stack should be maintained at a predetermined temperature in order to more stably generate the electrical energy, and the fuel treatment device should be subjected to efficient heat recovery in order to prevent a thermal imbalance from occurring. That is, it is preferable that the constituent members such as the fuel cell stack and the fuel treatment device are subjected to the heat recovery according to each heat generation amount.
• the heat recovery apparatus of the fuel cell system according to the related art recovers the heat while sequentially passing through the constituent members of the fuel cell power generating apparatus, such as the fuel cell stack and the fuel treatment device, it is difficult that the heat is exchanged suitably for each constituent member.
• the heat recovery apparatus of the fuel cell system according to the related art causes the power generation efficiency and durability of the fuel cell system to deteriorate due to temperature non-uniformity of the fuel cell stack or a thermal imbalance of the fuel treatment device as the case may be.
• an object of the present invention is to provide a heat recovery apparatus of a fuel cell system that is capable of effectively recovering waste heat generated from constituent members of the fuel cell system without being influenced by a change of a surrounding environment of the fuel cell system and a change of internal temperature of a heat storage tank by separately recovering the waste heat.
• another object of the present invention is to provide a heat recovery apparatus of a fuel cell system that improves a utilization factor of the waste heat in a heat storage tank by enhancing a heat recovery circulating structure and an exhaust structure in the heat storage tank.
• a heat recovery apparatus of a fuel cell system includes: a first heat exchanger that recovers waste heat generated from a fuel cell stack; a second heat exchanger installed independently from the first heat exchanger, which recovers waste heat generated from a fuel treatment device or system pipes; and a heat storage tank supplying heat exchange material to the first heat exchanger and the second heat exchanger and recovers the heat exchange material to supply waste heat included in the heat exchange material to the outside in accordance with an external heat demand.
• One first pipe passage is connected from the heat storage tank, the first pipe passage is branched into a second pipe passage and a third pipe passage prior to the first heat exchanger and the second heat exchanger, and the second pipe passage and the third pipe passage are connected to the first heat exchanger and the second heat exchanger, respectively.
• a fourth pipe passage is connected to the first pipe passage so that the heat exchange material may join the first pipe passage via another route.
• An air-cooled radiator is installed in the fourth pipe passage and a first 3-way valve for selectively changing the flowing direction of the heat exchange material is installed in one portion of the first pipe passage, which is branched to the fourth pipe passage.
• a first check valve and a first pump that allow the heat exchange material to flow in one direction are installed in the second pipe passage.
• a second check valve and a second pump that allow the heat exchange material to flow in one direction are installed in the third pipe passage.
• the heat storage tank receives the heat exchange material from the outside, circulates the heat exchange material in the first heat exchanger and the second heat exchanger, and stores the heat exchange material as a waste heat containing material.
• a first heat exchange passage is installed in the heat storage tank, and water introduced into the first heat exchange passage is converted into hot water by exchanging heat with the waste heat contained material and is supplied to the outside of the heat storage tank.
• a second heat exchange passage is installed in the heat storage tank, and water introduced into the second heat exchange passage is converted into heating water by exchanging the heat with the waste heat contained material and is supplied to the outside of the heat storage tank.
• the heat recovery apparatus of the fuel cell system further includes a third heat exchanger that exchanges the heat with hot water or the heating water discharged from the heat storage tank, and a first auxiliary burner that generates heat depending on an external control signal to supply the heat to the third heat exchanger.
• the heat recovery apparatus of the fuel cell system further includes a temperature control valve in to where the hot water passing through the third heat exchanger and cool water supplied from the outside are introduced and mixed with each other.
• the temperature control valve is a tempering valve type valve that mixes the hot water with the cool water by using a temperature sensing operating element alloy.
• the heat recovery apparatus of the fuel cell system has a pipe structure in which the heating water passing the third heat exchanger is supplied to the outside so as to serve to perform a heating function and the heating water is again recovered to the heat storage tank.
• a second 3-way valve is installed on a pipe route through which the heating water is recovered to the heat storage tank, thereby allowing the heating water to be introduced into the heat storage tank or supplied to the outside through a bypass route by selectively operating the second 3-way valve.
• the heat recovery apparatus of the fuel cell system may further include a fourth heat exchanger that exchanges the heat with the hot water discharged from the heat storage tank, and a second auxiliary burner that supplies the heat to the fourth heat exchanger by generating the heat depending on the external control signal.
• the heat recovery apparatus of the fuel cell system may further include a fifth heat exchanger that is installed independently from the fourth heat exchanger and exchanges the heat with the heating water discharged from the heat storage tank, and a third auxiliary burner that generates the heat depending on the external control signal to supply the heat to the fifth heat exchanger.
• a water level sensor for measuring the water level of the heat exchange material is installed in the heat storage tank.
• a water supply pipe is connected to the heat storage tank so that the water as the heat exchange material is supplied to the heat storage tank, and a solenoid valve for adjusting the supply quantity of the water in synchronization with the measurement data of the water level sensor is installed in the water supply pipe.
• a safety valve for decreasing the internal pressure of the heat storage tank generated by the heat exchange material to a pressure less than a predetermined overpressure condition is installed in an upper part of the heat storage tank.
• a drain valve for discharging the heat exchange material to the outside as necessary is installed in a lower part of the heat storage tank.
• ADVANTAGEOUS EFFECTS In a fuel cell system, a heat generation quantity depends on a change of a surrounding environment (generally, a change of a surrounding temperature), and starting, operating, and stopping processes of the system.
• waste heat generated from a fuel cell stack and waste heat generated from other constituent members such as a fuel treatment device, and the like are independently recovered. That is, the heat recovery apparatus of the fuel cell system according to an exemplary embodiment of the present invention can recover heat while independently corresponding to the constituent members, thereby improving heat recovery efficiency.
• the heat recovery apparatus of the fuel cell system can improve a waste heat using ratio in the heat storage tank by enhancing a heat recovery and circulation structure and a heat discharge structure in the heat storage tank.
• a heat recovery apparatus of a fuel cell system according to an exemplary embodiment of the present invention can reduce fuel consumption and increase economical benefits in comparison with the related art by using an auxiliary heat source machine such as an auxiliary burner additionally providing a heat source in an optimum state. DESCRIPTION OF DRAWINGS
• FIG. 1 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a first exemplary embodiment of the present invention.
• FIG. 2 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a second exemplary embodiment of the present invention.
• FIG. 3 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a third exemplary embodiment of the present invention.
• FIG. 4 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a fourth exemplary embodiment of the present invention.
• FIG. 5 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a fifth exemplary embodiment of the present invention.
• Fuel treatment device 120, 220, 320, 420, 520 Fuel treatment device
• Second heat exchanger 160, 260, 360, 460, 560 Air-cooled radiator
• FIG. 1 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a first exemplary embodiment of the present invention.
• a heat recovery apparatus 100 of a fuel cell system stores waste heat recovered in a heat storage tank 130 by separately recovering waste heat generated from a fuel cell stack and waste heat generated from other constituent members such as a fuel treatment device or system pipes.
• Heat generated from the inside of the fuel cell system is generally classified into two types. That is, a fuel cell stack 110 generates heat while generating electric power by an electrochemical reaction of hydrogen and oxygen.
• the heat of the fuel cell stack 110 is generally lower than 8O 0 C and constitutes approximately 70 to 80% of entire recovered waste heat.
• Other constituent members such as a fuel treatment device 120 or the system pipes also generate heat during operation, which constitutes 20 to 30% of the entire recovered waste heat.
• the heat recovery apparatus 100 of the fuel cell system may adjust a circulation supply amount of a heat exchange material that corresponds to the most suitable condition or select a processing capacity of a heat exchanger in accordance with a heat generation amount in the constituent member such as the fuel cell stack 110 or the fuel treatment device 120. Therefore, the fuel cell stack 110 may have improved power generation efficiency while it is maintained at a predetermined temperature and the fuel treatment device 120 may also stably operate without thermal imbalance.
• the heat storage tank 130 recovers the waste heat generated from the fuel cell stack 110 or the fuel treatment device 120 to store the waste heat in hot water or heating water.
• the heat storage tank 130 supplies the hot water or heating water to the outside in accordance with an external heat demand.
• the heat storage tank 130 receives water as the heat exchange material to recover the waste heat and supplies the heat exchange material to a first heat exchanger 140 and a second heat exchanger 150 again.
• the first heat exchanger 140 is connected to the fuel cell stack 110 and is configured to allow the waste heat generated from the fuel cell stack 110 to exchange the heat with the heat exchange material. As a result, the waste heat generated from the fuel cell stack 110 is included in the heat exchange material. The heat exchange material is recovered to the heat storage tank 130.
• the second heat exchanger 150 is installed independently from the first heat exchanger 140.
• the second heat exchanger 150 is connected to other constituent members of the fuel cell system, such as the fuel treatment device 120.
• the waste heat generated from the fuel treatment device 120 is configured to exchange the heat with the heat exchange material. As a result, the waste heat generated from the fuel treatment device 120 is included in the heat exchange material.
• the heat exchange material is recovered to the heat storage tank 130.
• the heat recovery apparatus 100 of the fuel cell system includes a pipe passage for allowing the heat exchange material to flow from the heat storage tank 130 to the first heat exchanger 140 or the second heat exchanger 150 as follows. That is, in the heat recovery apparatus 100 of the fuel cell system, one first pipe passage 164 is connected from an inlet port 131 of the heat storage tank 130, but the first pipe passage 164 is branched into a second pipe passage 144 and a third pipe passage 154 prior to the first heat exchanger 140 and the second heat exchanger 150.
• the second pipe passage 144 is connected to the first heat exchanger 140 and the third pipe passage 154 is connected to the second heat exchanger 150.
• a first pump 141 is installed in the second pipe passage 144 so that the heat exchange material is supplied at a predetermined flow rate.
• a second pump 151 is installed in the third pipe passage 154 so that the heat exchange material is supplied at the predetermined flow rate.
• temperature sensors 242 and 252 are installed in the pipe passages through which the heat exchange material is recovered to the heat storage tank 130, respectively.
• the temperature sensors 242 and 252 measure the temperature of the heat exchange material. The measured temperature is utilized as control data for determining the flow rate of the heat exchange material in the first pump 141 and the second pump 151 independently.
• a route for recovering the heat exchange material from the second heat exchanger 150 to the heat storage tank 130 is connected to the second pipe passage 144 to allow the heat exchange material passing through the second heat exchanger 150 to flow into the first heat exchanger 140, as shown in FIG. 1.
• a route for recovering the heat exchange material from the second heat exchanger 150 to the heat storage tank 130 has another structure and may be formed independently from the route for recovering the heat exchange material from the first heat exchanger 140 to the heat storage tank 130.
• a fourth pipe passage 165 is connected to the first pipe passage 164 so that the heat exchange material may join the first pipe passage 164 via another route.
• An air-cooled radiator 160 is installed in the fourth pipe passage 165.
• a first 3-way valve 161 for selectively changing the flow direction of the heat exchange material is installed in one portion of the first pipe passage 164, which is branched to the fourth pipe passage 165. That is, in the case when the external heat demand (the usage of hot water or heating water) is low in the summer season, the flow route of the heat exchange material is changed at a first 3-way valve 161 , thereby causing the heat of the heat exchange material to be emitted from the air-cooled radiator 160.
• a plurality of ports for introducing or discharging the heat exchange material are formed in the heat storage tank 130.
• the plurality of ports include the inlet port 131 that allows the water that is the heat exchange material to flow into the first heat exchanger 140 or the second heat exchanger 150 and an outlet port 132 that allows the heat exchange material recovering the waste heat from the first heat exchanger 140 or the second heat exchanger 150 to flow in the heat storage tank 130.
• the inlet port 131 is generally positioned below the heat storage tank 130 and the outlet port 132 is positioned relatively above the inlet port 131.
• the plurality of ports further include a water supply port that receives the water as the heat exchange material from the outside, and a hot water discharge port or a heating water discharge port that discharges the hot water or the heating water in accordance with the external heat demand.
• the water supply port is generally positioned below the heat storage tank 130, and the hot water discharge port and the heating water discharge port are positioned relatively above the water supply port. Therefore, in the heat recovery apparatus 100 of the fuel cell system, a difference in temperature between the heat exchange material in the upper part and the lower part of the heat storage tank 130 is maintained within a predetermined range, and the heating exchange material containing the waste heat may be utilized as the hot water or the heating water.
• FIG. 2 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a second exemplary embodiment of the present invention.
• a heat recovery apparatus 200 of a fuel cell system further includes a first check valve 243 and a second check valve 253 in comparison with the heat recovery apparatus 100 of the fuel cell system shown in FIG. 1. That is, the first check valve 243 and the second check valve 253 are constituent members for preventing a heat exchange material from flowing backward to the heat storage tank 130 during when the heat exchange material flows.
• the first check valve 243 is positioned downstream of a first pump 241 in a second pipe passage 244 on the basis of the flow direction of the heat exchange material, thereby allowing the heat exchange material to flow only toward a first heat exchanger 240 without flowing backward to the heat storage tank 130.
• the first check valve 253 is also positioned downstream of a second pump 251 in a third pipe passage 254 on the basis of the flow direction of the heat exchange material, thereby allowing the heat exchange material to flow only toward a second heat exchanger 250 without flowing backward to the heat storage tank 130.
• first check valve 243 and the second check valve 253 are together shown in FIG. 2, any one of the two valves 243 and 253 may be installed as necessary.
• Other constituent members of the heat recovery apparatus 200 of the fuel cell system correspond to and perform the same functions as the constituent members of the heat recovery apparatus 100 of the fuel cell system shown in FIG. 1. Therefore, the description thereof will be omitted.
• FIG. 3 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a third exemplary embodiment of the present invention.
• a heat recovery apparatus 300 of a fuel cell system according to a third exemplary embodiment of the present invention further includes constituent members for supplying hot water or heating water to the outside or recovering the hot water or the heating water in accordance with an external heat demand in comparison with the heat recovery apparatus 200 of the fuel cell system shown in FIG. 2.
• a heat storage tank 330 receives water as a heat exchange material from the outside and circulates the heat exchange material in a first heat exchanger 340 and a second heat exchanger 350. Thereafter, the heat storage tank 330 stores the heat exchange material as a waste heat containing material. That is, the water, which is the heat exchange material, is circulated in the first heat exchanger 340 and the second heat exchanger 350, and is stored in the heat storage tank 330 containing the waste heat, whereby the waste heat containing material is acquired. Since hot water is used for washing-up and cleansing, a closed-circuit is configured in order to prevent the hot water from being mixed with the waste heat containing material for sanitation management.
• the hot water receives heat through a first heat exchange passage 333 that is a closed-circuit configuration in the heat storage tank 330.
• Water introduced through a first water supply port 334 exchanges heat with the waste heat containing material stored in the heat storage tank 330 while passing through the first heat exchange passage 333.
• the water passing through the first heat exchange passage 333 is converted into hot water of a predetermined temperature or higher and is supplied to the outside having a heat demand through a hot water discharge port 335.
• the heating water is discharged through a heating water discharge port 337 positioned above the heat storage tank 330 and is again introduced into the heat storage tank 330 through a heating water introduction port 338 positioned below the heat storage tank 330.
• the heating water may contain contamination material from circulating through an external heating water pipe in accordance with a utility environment installed in the fuel cell system, another closed-circuit may be configured in order to prevent the heating water from being mixed with the waste heat containing material of the heat storage tank 330, like with the hot water. That is, the heating water also receives the heat through a second heat exchange passage 339 that is a closed-circuit configuration in the heat storage tank 330.
• the heat recovery apparatus 300 of the fuel cell system is configured to allow the heating water to be recirculated.
• the heat recovery apparatus 300 of the fuel cell system may utilize the waste heat containing material as the heating water without the second heat exchange passage 339 as necessary. Therefore, the water introduced through the second water supply port 336, as the heat exchange material, contains the waste heat by heat exchange in the first heat exchanger 340 and the second heat exchanger 350.
• the waste heat containing material, as the heating water circulates through the heating water discharge port 337 and the heating water introduction port 338.
• the temperature of the heating water is low in the case when the heating water is introduced into the heat storage tank 330 again, the temperature of the heating water may increase up to a predetermined temperature again by the heat exchange in the first heat exchanger 340 and the second heat exchanger 350.
• the heat recovery apparatus 300 of the fuel cell system includes an auxiliary heat source machine 370 so that the temperatures of the hot water and the heating water discharged from the heat storage tank 330 can reincrease up to the predetermined temperature or higher.
• the auxiliary heat source 370 includes a third heat exchanger 371 and a first auxiliary burner 372.
• the third heat exchanger 371 is installed on discharge routes of the hot water and the heating water, and is configured to exchange the heat with the hot water or the heating water.
• the first auxiliary burner 372 generates the heat in accordance with an external control signal and provides heat required by the third heat exchanger 371.
• the heat recovery apparatus 300 of the fuel cell system further includes a temperature control valve 373 that mixes the hot water and cool water to be suitable for using the water.
• the hot water passing through the third heat exchanger 371 and the cool water supplied from the outside are introduced into the temperature control valve 373.
• the hot water and the cool water are discharged from the temperature control valve 373 with the hot water and the cool water mixed with each other.
• the temperature control valve 373 a tempering valve type using a temperature sensing operating element alloy, may always supply hot water of a predetermined temperature range without requiring power consumption.
• the heat recovery apparatus 300 of the fuel cell system has a pipe structure in which the heating water is recovered to the heat storage tank 330.
• a third pump 374 is installed on a pipe route through which the heating water is supplied from the heat storage tank 330 to the third heat exchange tank 371 , thereby allowing heating water having a predetermined flow rate to flow.
• a second 3-way valve 375 is installed on a pipe route through which the heating water is recovered to the heat storage tank 330. The second 3-way valve 375 allows the recovered heating water to be introduced into heat storage tank 330 or to be recirculated through a bypass route without passing through the heat storage tank 330 on the basis of the temperature of the heating water in the heat storage tank 330.
• the heat recovery apparatus 300 of the fuel cell system is configured to allow the heat exchange material to be discharged from a lower part of the heat storage tank 330 and introduced into an upper part of the heat storage tank 330 at the time of recovering the waste heated generated from a fuel cell stack 310 or a fuel treatment device 320.
• the heat recovery apparatus 300 of the fuel cell system is configured to allow the heating water to be discharged from the upper part of the heat storage tank 330 and to be introduced into the lower part of the heat storage tank 330 at the time of circulating the heating water. Therefore, a difference in temperature between the heat exchange material (or heating water) in the upper and lower part of the heat storage tank 330 is constantly maintained within a predetermined range, whereby the utilization factor of the waste heat is improved.
• the difference in temperature between the heat exchange material (or heating water) in the heat storage tanks 330 is maintained as follows. That is, it is preferable that the difference in temperature of the heat exchange material is maintained within the range of 8 0 C to 12 0 C between the inlet port 331 and the outlet port 332 of the heat storage tank 330.
• the processing capacity of each of the first heat exchanger 340 and the second heat exchanger 350 is determined depending on the difference.
• FIG. 4 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a fourth exemplary embodiment of the present invention.
• a heat recovery apparatus 400 of a fuel cell system further includes a safety valve 480, a drain valve 481 , a water level sensor 482, and a solenoid valve 483 in comparison with the heat recovery apparatus of the fuel cell system shown in FIG. 3.
• the safety valve 480 actuates in the case when the internal pressure of a heat storage tank 430 by a heat exchange material in an upper part of the heat storage tank 430 is more than a predetermined overpressure condition to decrease the internal pressure of the heat storage tank 430.
• the drain valve 481 is installed below the heat storage tank 430. The drain valve 481 allows the heat exchange material stored in the heat storage tank 430 to be discharged by automatic control or manual manipulation as necessary.
• the water level sensor 482 is installed inside or outside the heat storage tank 430 to measure the level of the heat exchange material stored in the heat storage tank 430.
• the solenoid valve 483 adjusts the supply quantity of water supplied to the inside of the heat storage tank 430 in synchronization with the measurement data of the water level sensor 482. That is, a water supply pipe is connected to a first water supply port 435 so that water, which is the heat exchange material, is supplied to the first water supply port 435 from the outside.
• FIG. 5 is a schematic diagram of a heat recovery apparatus of a fuel cell system according to a fifth exemplary embodiment of the present invention.
• a heat recovery apparatus 500 of a fuel cell system includes an auxiliary heat source machine 570, separated into two corresponding to hot water and heating water respectively, in comparison with the heat recovery apparatus 400 of the fuel cell system shown in FIG. 4.
• the auxiliary heat source machine 570 includes a fourth heat exchanger
• the auxiliary heat source machine 570 further includes a fifth heat exchanger 571 that is installed independently from the fourth heat exchanger 571 and exchanges the heat with the heating water discharged from the heat storage tank 530 and a third auxiliary burner 577 that generates the heat depending on the external control signal to supply the heat to the fifth heat exchanger 576.
• the heat recovery apparatus 500 of the fuel cell system includes dual auxiliary heat source machines 570 to selectively heat the hot water or the heating water.
• the auxiliary heat source machine 570 uses the fourth heat exchanger 571 and the second auxiliary burner 572 for heating the hot water in the case when a heat demand is low in the summer season and uses the fifth heat exchanger 576 and the third auxiliary burner 577 for heating the heating water in the case when the heat demand is high in the winter season. Therefore, the second auxiliary burner 572 and the third auxiliary burner 577 are selectively used in correspondence with the hot water and the heating water, whereby it is possible to save the fuel consumption of the auxiliary heat source machine 570.
• Other constituent members of the heat recovery apparatus 500 of the fuel cell system correspond to and perform the same functions as the constituent members of the heat recovery apparatus 400 of the fuel cell system shown in FIG. 4. Therefore, the description thereof will be omitted.

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• 2007
  • 2007-10-19 KR KR1020070105501A patent/KR100911055B1/ko active IP Right Grant
• 2008
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