JP5295257B2 - Heat recovery device for fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system that produces electric energy by an electrochemical reaction of hydrogen and oxygen, and more specifically, effectively generates heat generated by various power generation components including a fuel cell stack. The present invention relates to a heat recovery device of a fuel cell system that recovers and supplies hot water or heated circulating water.

  A fuel cell is a power generation device that generates electrical energy through a hydrogen oxidation reaction and an oxygen reduction reaction. This fuel cell is classified into a polymer electrolyte fuel cell (Polymer Electrolyte Fuel Cell), a direct oxidation fuel cell (Direct Oxidation Fuel Cell), and the like.

Among these, a polymer electrolyte fuel cell is a fuel cell that uses a polymer membrane having hydrogen ion exchange characteristics as an electrolyte, and induces an electrochemical reaction using a fuel containing hydrogen and air containing oxygen. To generate electrical energy. A fuel cell system using such a polymer electrolyte fuel cell generally has the following structure.
In other words, if the fuel cell system is roughly divided, the fuel cell power generation unit for generating electric energy and the waste heat generated in such a fuel cell power generation unit are recovered and there is a heat demand. It can be divided into a heat recovery device to be supplied to the place.

  The fuel cell power generation unit reforms fuel cell stacks that generate direct current (DC) power through an electrochemical reaction between hydrogen and oxygen, and hydrocarbon-based power generation materials such as natural gas (LNG) or liquefied petroleum gas (LPG). A fuel processing device that supplies reformed gas rich in hydrogen to the fuel cell stack, an air supply device that supplies oxygen required by the fuel cell stack, and direct current power generated in the fuel cell stack is converted to alternating current power Power converters, various peripheral devices (BOP: Balance of Plants) necessary for starting, stopping, and maintaining the power generation state of the components, and a controller.

  The heat recovery device of the fuel cell system is roughly configured as follows, with reference to the matters known in Korean Patent Registration Nos. 01845959 and 0740542. That is, the heat recovery device of the fuel cell system according to the prior art supplies a heat storage tank that stores the waste heat recovered from the fuel cell power generation unit, and supplies the waste heat stored in such a heat storage tank to the hot water or the heating circulating water. Means.

  In particular, the heat recovery device of the fuel cell system is configured to recover waste heat generated from various system components such as the fuel cell stack and the fuel processing device in the fuel cell power generation unit. At this time, the fuel cell stack in the fuel cell power generation unit must be maintained at a constant temperature in order to generate electric energy more stably, and the fuel processing apparatus also does not generate thermal imbalance. Heat recovery must be performed efficiently. That is, it is desirable that the components such as the fuel cell stack and the fuel processing apparatus are subjected to heat recovery corresponding to the degree of heat generation.

  However, the heat recovery device of the conventional fuel cell system is configured to recover heat while sequentially passing through the components of the fuel cell power generation unit such as the fuel cell stack and the fuel processing device. There is a problem that heat exchange is not performed in accordance with the element. Accordingly, in the heat recovery device of the fuel cell system according to the conventional technology, the power generation efficiency and durability of the fuel cell system are lowered due to the uneven temperature of the fuel cell stack or the thermal imbalance of the fuel processing device.

  As described above, the present invention has been proposed to solve the problems of the prior art, and the heat recovery device of the fuel cell system according to the embodiment of the present invention is a component of the fuel cell system. By recovering the waste heat generated in the fuel cell individually, it is possible to effectively recover the waste heat without being affected by changes in the surrounding environment of the fuel cell system and changes in the internal temperature of the heat storage tank. An object of the present invention is to provide a heat recovery device for a fuel cell system.

  In addition, the heat recovery apparatus of the fuel cell system according to the embodiment of the present invention can improve the waste heat utilization rate in the heat storage tank by improving the heat recovery circulation structure and the discharge structure in the heat storage tank. The object is to provide a heat recovery device for the system.

  A heat recovery device of a fuel cell system according to an embodiment of the present invention is installed separately from a first heat exchanger that recovers waste heat generated in a fuel cell stack and the first heat exchanger, and is a fuel processing device or system. A second heat exchanger that recovers waste heat generated in the piping; and a heat exchange material is supplied to each of the first heat exchanger and the second heat exchanger, the heat exchange material is recovered, and the heat exchange is performed. It includes a heat storage tank that supplies waste heat contained in the substance to the outside by external heat demand.

One first pipe through passage is connected from the heat storage tank, and the first pipe passage branches into a second pipe passage and a third pipe passage prior to the first heat exchanger and the second heat exchanger, respectively. The second pipe passage is connected to the heat storage tank via the first heat exchanger, and the third pipe passage is connected to the first heat exchange material via the second heat exchanger. The heat exchanger is formed so as to flow into the heat exchanger or to be collected in the heat storage tank without passing through the first heat exchanger.

A fourth piping passage is connected to the first piping passage so that the heat exchange material joins via another route. An air-cooled radiator is installed in the fourth pipe passage, and the first pipe passage or the fourth pipe as the direction of travel of the heat exchange material is provided in the first pipe passage at a point branched to the fourth pipe passage . A first three-way valve that selects one of the pipe passages is installed.

The second pipe passage is measured by a first check valve for causing the heat exchange material to flow in one direction, a first temperature sensor for measuring the temperature of the heat exchange material recovered in the heat storage tank, and the first temperature sensor. In addition, a first pump for adjusting a flow amount of the heat exchange material supplied to the first heat exchanger according to a temperature of the heat exchange material collected in the heat storage tank is installed. The third pipe passage is measured by a second check valve that allows the heat exchange material to flow in one direction, a second temperature sensor that measures the temperature of the heat exchange material recovered in the heat storage tank, and the second temperature sensor. In addition, a second pump for adjusting a flow amount of the heat exchange material supplied to the second heat exchanger according to a temperature of the heat exchange material collected in the heat storage tank is installed.

The heat storage tank receives the supply of the heat exchange material from the outside, and stores the heat exchange material after passing through the first heat exchanger and the second heat exchanger.

The inside of the storage tank is installed first heat exchange passages, the consumption for supplying water flowing into the first heat exchange passages, are warm through heat exchange with the heat exchange material, the heat storage tank Supplied outside.

Inside the heat storage tank is installed a second heat exchange passages, the air-heating circulation water in the second heat exchange passages, it is warm through heat exchange with the heat exchange material, the outside of the heat storage tank To be supplied.

  The heat recovery device of the fuel cell system is configured to generate heat by the third heat exchanger that exchanges heat while passing the waste heat-containing material discharged from the heat storage tank, and an external control signal, so that the third heat Further included is a first auxiliary burner for supplying heat to the exchanger.

The heat recovery device of the fuel cell system may further include a temperature control valve that mixes the consumption supply water that has passed through the third heat exchanger and the temperature adjustment water supplied from the outside.

The temperature control valve is a tempering valve type in which the supply water for consumption and the temperature adjustment water are mixed using a temperature sensing operation element alloy.

The heat recovery device of the fuel cell system is supplied to the outside so that the circulating water for heating that has passed through the third heat exchanger plays a role of heating, and the circulating water for heating is recovered again in the heat storage tank It consists of a piping structure. A second three-way valve is installed on a piping path through which the circulating water for heating is collected in the heat storage tank, and the circulating water for heating is supplied to the heat storage tank by selective operation of the second three-way valve. It flows in or is supplied to the outside again through a bypass path.

The heat recovery device of the fuel cell system is configured to generate heat by the fourth heat exchanger that exchanges heat while the consumption water discharged from the heat storage tank passes, and an external control signal, so that the fourth heat A second auxiliary burner for supplying heat to the exchanger can be further included. And the heat recovery device of the fuel cell system is installed separately from the fourth heat exchanger, and a fifth heat exchanger for exchanging heat while passing the circulating water for heating discharged from the heat storage tank, And a third auxiliary burner that generates heat according to an external control signal and supplies 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 water is supplied as the heat exchange material, and the water supply pipe is coupled with the measurement data of the water level sensor to adjust the water supply amount. Valve is installed.

  A safety valve for lowering the internal pressure of the heat storage tank by the heat exchange material below a set overpressure condition is installed at the upper part of the heat storage tank.

  A drain valve for discharging the heat exchange material to the outside as needed is installed at the lower part of the heat storage tank.

  Fuel cell systems vary in the degree of heat generation depending on changes in the surrounding environment (mostly changes in ambient temperature) and the process of starting and stopping the system. At this time, the heat recovery device of the fuel cell system according to the embodiment of the present invention individually recovers the waste heat generated in the fuel cell stack and the waste heat generated in other components such as the fuel processing device. Configure. That is, the heat recovery apparatus of the fuel cell system according to the embodiment of the present invention has an advantage that heat recovery efficiency is increased because heat recovery can be performed individually corresponding to each component. As a result, the thermal imbalance among the internal components is eliminated in the fuel cell system, and electric power can be stably produced with higher power generation efficiency than the conventional technology.

  Further, the heat recovery apparatus of the fuel cell system according to the embodiment of the present invention has an advantage that the waste heat utilization rate in the heat storage tank is improved by improving the heat recovery circulation structure and the discharge structure in the heat storage tank.

  In addition, the heat recovery apparatus of the fuel cell system according to the embodiment of the present invention uses an auxiliary heat source device such as an auxiliary burner that additionally provides a heat source in an optimal state, so that it can The fuel consumption is reduced and the economic utility is improved.

It is the schematic of the heat recovery apparatus of the fuel cell system by the reference example of this invention. 1 is a schematic view of a heat recovery device of a fuel cell system according to a first embodiment of the present invention. It is the schematic of the heat recovery apparatus of the fuel cell system by 2nd Example of this invention. It is the schematic of the heat recovery apparatus of the fuel cell system by 3rd Example of this invention. It is the schematic of the heat recovery apparatus of the fuel cell system by 4th Example of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the embodiments. The present invention can be embodied in various different forms and is not limited to the embodiments described herein.

FIG. 1 is a schematic view of a heat recovery device of a fuel cell system according to a reference example of the present invention.

  As shown in FIG. 1, the heat recovery device 100 of the fuel cell system includes waste heat generated in the fuel cell stack and other waste heat generated in other components such as a fuel processing device or system piping. Are separately collected, and the waste heat collected in the heat storage tank 130 is stored.

  Heat generated in the fuel cell system is roughly classified into two types. That is, in the fuel cell stack 110, hydrogen and oxygen are electrochemically reacted to produce electric power, and heat is also generated. The heat of the fuel cell stack 110 is mainly less than 80 ° C. and occupies about 70% to 80% of the total waste heat recovered. And other components, such as fuel processor 120 or system piping, also generate heat during their operation, but account for 20% to 30% of the total recovered waste heat.

  Therefore, the heat recovery device 100 of the fuel cell system adjusts the circulation supply amount of the heat exchange material corresponding to the most suitable condition according to the degree of heat generation in the components such as the fuel cell stack 110 or the fuel processing device 120. The processing capacity of the heat exchanger can be selected and used. As a result, the fuel cell stack 110 is maintained at the set temperature, the power generation efficiency can be improved, and the fuel processing device 120 can also operate stably without thermal imbalance.

  The heat storage tank 130 collects waste heat generated in the fuel cell stack 110 or the fuel processing device 120 and stores it as warm water or heating water. And the thermal storage tank 130 supplies warm water or heating water to the exterior by the external heat demand. At this time, the heat storage tank 130 is supplied with water as a heat exchange material in order to recover waste heat, and again supplies such heat exchange material to the first heat exchanger 140 and the second heat exchanger 150, respectively. .

  The first heat exchanger 140 is installed so as to be connected to the fuel cell stack 110, and is configured such that waste heat generated in the fuel cell stack 110 is heat-exchanged with a heat exchange material. Then, waste heat generated in the fuel cell stack 110 is included in the heat exchange material, and such heat exchange material is recovered in the heat storage tank 130.

  The second heat exchanger 150 is installed separately from the first heat exchanger 140. The second heat exchanger 150 is installed so as to be connected to other components of the fuel cell system such as the fuel processor 120 so that the waste heat generated in the fuel processor 120 is exchanged with the heat exchange material. Configured. If it does so, the waste heat which generate | occur | produces in the fuel processing apparatus 120 will be contained in the heat exchange material, and such a heat exchange material will be collect | recovered by the heat storage tank 130. FIG.

  At this time, the heat recovery apparatus 100 of the fuel cell system includes a piping passage for flowing the heat exchange material 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 piping passage 164 is connected from the inlet port 131 of the heat storage tank 130, but the first heat exchanger 140 and the second heat exchanger 150 are first connected. One piping passage 164 is branched into a second piping passage 144 and a third piping passage 154, respectively. The second piping passage 144 is connected to the first heat exchanger 140, and the third piping passage 154 is connected to the second heat exchanger 150. The first pump 141 is installed in the second pipe passage 144 so that the heat exchange material is supplied in a set flow amount, and the heat exchange material is also supplied in the third pipe passage 154 in a set flow amount. As a result, the second pump 151 is installed.

  The heat recovery apparatus 100 of the fuel cell system installs temperature sensors 242 and 252 in piping passages for recovering the heat exchange material in the heat storage tank 130, respectively. The temperature sensors 242 and 252 measure the temperature of the heat exchange material, and the measured temperature determines the flow rate of the heat exchange material independently by the first pump 141 and the second pump 151. Used as control data.

  As shown in FIG. 1, the path for collecting the heat exchange material from the second heat exchanger 150 to the heat storage tank 130 is connected to the second piping passage 144 and the heat that has passed through the second heat exchanger 150. The exchange material may flow into the first heat exchanger 140. The path for collecting the heat exchange material from the second heat exchanger 150 to the heat storage tank 130 may be formed separately from the path for collecting the heat exchange material from the first heat exchanger 140 to the heat storage tank 130 as another structure.

  A fourth piping passage 165 is connected to the first piping passage 164 so that the heat exchange materials join together via other paths. An air-cooled heat radiator 160 is installed in the fourth pipe passage 165, and the first pipe passage 164 at a point branched to the fourth pipe passage 165 selectively changes the traveling direction of the heat exchange material. 1 A three-way valve 161 is installed. That is, when the external heat demand (use of warm water or heating water) is low as in the summer, the flow path of the heat exchange material is changed to the first three-way valve 161, and the air-cooled radiator 160 changes the heat exchange material to the heat exchange material. Allow the contained heat to be dissipated.

  In addition, the heat storage tank 130 is formed with a plurality of ports for allowing the heat exchange material to flow in and out. The plurality of ports are waste heat in the inlet port 131 through which water, which is a heat exchange material, flows into the first heat exchanger 140 or the second heat exchanger 150, and in the first heat exchanger 140 or the second heat exchanger 150. It includes an outlet port 132 through which the heat exchange material that has been recovered flows into the heat storage tank 130. The inlet port 131 is generally located at the lower part of the heat storage tank 130, and the outlet port 132 is located at a point corresponding to the upper side relative to the inlet port 131. The plurality of ports further include a water supply port that receives supply of water as a heat exchange material from the outside, a hot water discharge port that discharges hot water or heating water according to external heat demand, and a heating water discharge port. The water supply port is generally located at the lower part of the heat storage tank 130, and the hot water discharge port and the heating water discharge port are relatively located at a point corresponding to the upper side of the water supply port.

  As a result, the heat recovery device 100 of the fuel cell system is maintained within a range in which the temperature difference of the heat exchange material is set between the upper part and the lower part of the heat storage tank 130, and the heat exchange material including waste heat is heated or heated. Can be utilized as.

FIG. 2 is a schematic view of a heat recovery apparatus of the fuel cell system according to the first embodiment of the present invention.

As shown in FIG. 2, the heat recovery apparatus 200 of the fuel cell system according to the first embodiment has a first check valve 243 and a second check valve 243 as compared with the heat recovery apparatus 100 of the fuel cell system shown in FIG. There is a feature further including a check valve 253. That is, the first check valve 243 and the second check valve 253 are components that prevent the heat exchange material from flowing back to the heat storage tank 130 in the process of flowing.

  Since the first check valve 243 is positioned downstream of the first pump 241 when the flow direction of the heat exchange material is based on the second piping passage 244, the first heat valve does not flow back into the heat storage tank 130 and the first heat It flows only in the direction of the exchanger 240. The second check valve 253 is also located downstream of the second pump 251 when the flow direction of the heat exchange material is based on the third piping passage 254, so that the heat exchange material does not flow back to the heat storage tank 130 and flows through the second check valve 253. 2 Flows only in the heat exchanger 250 direction.

  However, although both the first check valve 243 and the second check valve 253 are shown in FIG. 2, only one of them may be installed as necessary. The other components of the heat recovery apparatus 200 of the fuel cell system perform the same functions corresponding to the components of the heat recovery apparatus 100 of the fuel cell system shown in FIG. Omitted.

FIG. 3 is a schematic view of a heat recovery device of a fuel cell system according to a second embodiment of the present invention.

As shown in FIG. 3, the heat recovery apparatus 300 of the fuel cell system according to the second embodiment is heated or heated according to external heat demand as compared with the heat recovery apparatus 200 of the fuel cell system shown in FIG. It further includes a component for supplying water to the outside and collecting it again.

  The heat storage tank 330 receives supply of water as a heat exchange material from the outside, circulates the heat exchange material to the first heat exchanger 340 and the second heat exchanger 350, and stores the heat exchange material as a waste heat-containing material. That is, the waste heat-containing material is stored in the heat storage tank 330 in a state where water, which is a heat exchange material, circulates through the first heat exchanger 340 and the second heat exchanger 350 and includes waste heat. .

  The hot water is configured in a closed circuit so that it is not mixed with waste heat-containing materials for hygiene purposes, for use by people for washing or washing. That is, the hot water is supplied with heat through the first heat exchange passage 333 having a closed circuit configuration inside the heat storage tank 330. The water that flows in through the first water supply port 334 is heat-exchanged with the waste heat-containing material stored in the heat storage tank 330 while passing through the first heat exchange passage 333. Thus, the water passing through the first heat exchange passage 333 is converted into hot water having a certain temperature or higher, and supplied to the outside where there is a heat demand through the hot water discharge port 335.

  The heating water is discharged through the heating water discharge port 337 located at the upper part of the heat storage tank 330 and flows again into the heat storage tank 330 through the heating water inflow port 338 located at the lower part of the heat storage tank 330. At this time, since the heating water may contain pollutants in the process of circulating through the external heating water piping depending on the utility environment installed in the fuel cell system, it is mixed with the waste heat-containing substance of the heat storage tank 330 in the same manner as the hot water. Alternatively, other closed circuits may be configured. That is, the heating water is also supplied with heat through the second heat exchange passage 339 having a closed circuit configuration inside the heat storage tank 330. Thus, the heat recovery device 300 of the fuel cell system is configured such that the heating water is recirculated.

  The heat recovery apparatus 300 of the fuel cell system uses the waste heat-containing material as heating water without providing the second heat exchange passage 339 separately as necessary. Then, the water flowing in through the second water supply port 336 includes waste heat through heat exchange in the first heat exchanger 340 and the second heat exchanger 350 as a heat exchange material, and such waste heat-containing material Circulates as heating water through the heating water discharge port 337 and the heating water inflow port 338.

  The heating water is in a state where the temperature is lowered when it flows into the heat storage tank 330 again, but rises to the set temperature again through heat exchange in the first heat exchanger 340 and the second heat exchanger 350.

  The heat recovery device 300 of the fuel cell system has a feature that the auxiliary heat source device 370 is provided so that the hot water and the heating water discharged from the heat storage tank 330 can rise again to a set temperature or higher. The auxiliary heat source device 370 includes a third heat exchanger 371 and a first auxiliary burner 372. The third heat exchanger 371 is installed on each discharge path of hot water and heating water, and is configured to exchange heat with the hot water or heating water, respectively. The first auxiliary burner 372 is heated by an external control signal to provide heat required by the third heat exchanger 371.

  The heat recovery apparatus 300 of the fuel cell system further includes a temperature adjustment valve 373 that mixes hot water and cold water so that the heat recovery apparatus 300 is suitable for people to use. The temperature control valve 373 receives hot water that has passed through the third heat exchanger 371 and cold water supplied from the outside, and is discharged in a state where the hot water and cold water are mixed with each other. The temperature control valve 373 is a tempering valve type that uses a temperature sensing operation element alloy, and can always supply hot water in a certain temperature range without requiring power consumption.

  The heat recovery apparatus 300 of the fuel cell system has a piping structure in which the heating water is recovered in the heat storage tank 330 as mentioned above. At this time, the 3rd pump 374 is installed in the piping path which supplies heating water from the heat storage tank 330 to the 3rd heat exchanger 371, and the heating water of the set flow volume flows. A second three-way valve 375 is installed in the piping path where the heating water is collected in the heat storage tank 330. The second three-way valve 375 determines the heating water temperature of the heat storage tank 330 as a reference, and allows the recovered heating water to flow into the heat storage tank 330 or bypass the heat storage tank 330 (by-pass) path. Cycle through again.

  As described above, when the heat recovery device 300 of the fuel cell system recovers waste heat generated in the fuel cell stack 310 or the fuel processing device 320, the heat exchange material is discharged from the lower portion of the heat storage tank 330 and the heat storage tank 330 is recovered. It is constructed so as to flow into the upper part. The heat recovery device 300 of the fuel cell system is configured such that the heating water is discharged from the upper part of the heat storage tank 330 and flows into the lower part of the heat storage tank 330 when the heating water is circulated. As a result, the heat exchange material (or heating water) is kept constant within a range in which the temperature difference between the upper part and the lower part of the heat storage tank 330 is set, and the utilization rate of waste heat is improved.

  However, if the heat recovery apparatus 300 of the fuel cell system is not in a state where the waste heat is stored beyond the limit that can be withstood by the heat storage tank 330, the temperature difference of the heat exchange material (or heating water) in the heat storage tank 330 is as follows. It is desirable to maintain the street. That is, the temperature difference of the heat exchange material is preferably maintained within the range of 8 ° C.-12 ° C. between the inlet port 331 and the outlet port 332 of the heat storage tank 330, and based on that, the first heat exchanger 340 and Each processing capacity of the second heat exchanger 350 is determined. The temperature difference of the heat exchange material (or heating water) is preferably maintained so that the upper and lower temperatures in the heat storage tank 330 are in the range of 8 ° C. to 40 ° C. Based on this, the first heat exchanger 340 and the second heat The flow rate of the heat exchange material in the exchanger 350 is determined.

  The other components of the heat recovery apparatus 300 of the fuel cell system perform the same functions corresponding to the components of the heat recovery apparatus 200 of the fuel cell system shown in FIG. Omitted.

FIG. 4 is a schematic view of a heat recovery apparatus of a fuel cell system according to a third embodiment of the present invention.

  As shown in FIG. 4, the heat recovery device 400 of the fuel cell system includes a safety valve 480, a drain valve 481, and a water level sensor compared to the heat recovery device 200 of the fuel cell system shown in FIG. 3. 482 and a solenoid valve 483 are further included.

  That is, the safety valve 480 operates when the internal pressure of the heat storage tank 430 by the heat exchange material is equal to or higher than the set overpressure condition in the upper part of the heat storage tank 430, and reduces the internal pressure of the heat storage tank 430. is there.

  The drain valve 481 is installed in the lower part of the heat storage tank 430. Such a drain valve 481 can discharge | emit the heat exchange material accommodated in the inside of the thermal storage tank 430 as needed by automatic control or manual operation.

  The water level sensor 482 is installed inside or outside the heat storage tank 430 so as to measure the water level of the heat exchange material filled in the heat storage tank 430.

  The solenoid valve 483 adjusts the amount of water supplied into the heat storage tank 430 in conjunction with the measurement data of the water level sensor 482. That is, a water supply pipe is connected to the first water supply port 435 so that water, which is a heat exchange material, is supplied from the outside, and a solenoid valve 483 is installed in such a water supply pipe, thereby providing water. The supply amount can be adjusted at any time as needed.

  The other components of the heat recovery apparatus 400 of the fuel cell system perform the same functions corresponding to the components of the heat recovery apparatus 300 of the fuel cell system shown in FIG. Omitted.

FIG. 5 is a schematic view of a heat recovery apparatus of a fuel cell system according to a fourth embodiment of the present invention.

  As shown in FIG. 5, in the heat recovery apparatus 500 of the fuel cell system, the auxiliary heat source device 570 corresponds to hot water and heating water, respectively, compared to the heat recovery apparatus 400 of the fuel cell system shown in FIG. There are two features that are installed separately.

  The auxiliary heat source device 570 supplies heat to the fourth heat exchanger 571 by heat generation by the fourth heat exchanger 571 that exchanges heat while the hot water discharged from the heat storage tank 530 passes and an external control signal. A second auxiliary burner 572 is provided. And the auxiliary heat source device 570 is installed separately from the 4th heat exchanger 571, the 5th heat exchanger 576 by which the heating water discharged | emitted from the heat storage tank 530 passes, and an external control signal And a third auxiliary burner 577 for supplying heat to the fifth heat exchanger 576.

  The heat recovery apparatus 500 of the fuel cell system can selectively additionally heat the hot water or the heating water by configuring the auxiliary heat source device 570 in this way. That is, the auxiliary heat source 570 uses the fourth heat exchanger 571 and the second auxiliary burner 572 for heating hot water when the heat demand is low as in the summer, and when the heat demand is high as in the winter. The fifth heat exchanger 576 and the third auxiliary burner 577 are used together for heating water heating. Accordingly, the second auxiliary burner 572 and the third auxiliary burner 577 are selectively used corresponding to hot water and heating water, so that the amount of fuel consumed by the auxiliary heat source 570 is saved.

  The other components of the heat recovery apparatus 500 of the fuel cell system perform the same functions corresponding to the components of the heat recovery apparatus 400 of the fuel cell system shown in FIG. Omitted.

  In other words, the preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and various modifications may be made within the scope of the claims, the detailed description of the invention, and the attached drawings. This is also within the scope of the present invention.

110, 210, 310, 410, 510: Fuel cell stack 120, 220, 320, 420, 520: Fuel processor 130, 230, 330, 430, 530: Heat storage tank 140, 240, 340, 440, 540: First Heat exchangers 150, 250, 350, 450, 550: second heat exchangers 160, 260, 360, 460, 560: air-cooled radiators 170, 270, 370, 470, 570: auxiliary heat source

Claims (12)

A first heat exchanger for recovering waste heat generated in the fuel cell stack;
A second heat exchanger installed separately from the first heat exchanger and recovering waste heat generated in the fuel processor or system piping; and heat in the first heat exchanger and the second heat exchanger, respectively. A heat storage tank for supplying an exchange material, recovering the heat exchange material, and supplying waste heat contained in the heat exchange material to the outside according to an external heat demand;
A first piping passage is connected to the heat storage tank , and the first piping passage is branched into a second piping passage and a third piping passage, respectively, prior to the first heat exchanger and the second heat exchanger. The second piping passage is connected to the heat storage tank via the first heat exchanger, and the third piping passage is connected to the first heat exchanger via the second heat exchanger. Formed to flow into the exchanger or to be collected in the heat storage tank without going through the first heat exchanger,
A fourth pipe passage is connected to the first pipe passage such that the heat exchange material joins via another path;
An air-cooled radiator is installed in the fourth pipe passage, and the first pipe passage or the fourth pipe as the direction of travel of the heat exchange material is provided in the first pipe passage at a point branched to the fourth pipe passage . A first three-way valve that selects one of the pipe passages is installed;
The second first temperature sensor in the pipe passage for measuring a first check valve for flowing the heat exchange material in one direction, the temperature of the heat exchange material is recovered to the heat storage tank, and measured by the first temperature sensor the first pump is installed, each to adjust the flow amount of the heat exchange material to be supplied to the first heat exchanger in accordance with the temperature of the heat exchange material is recovered to the heat storage tank, which is,
The third second temperature sensor in the pipe passage for measuring a second check valve for flowing the heat exchange material in one direction, the temperature of the heat exchange material is recovered to the heat storage tank, and measured by the second temperature sensor second pump to adjust the flow amount of the heat exchange material to be supplied to the heat exchanger and the second heat exchanger in accordance with the temperature of the material to be recovered to the heat storage tank that is are installed respectively, a fuel cell system Heat recovery equipment. 2. The fuel according to claim 1, wherein the heat storage tank receives the supply of the heat exchange material from the outside and stores the heat exchange material after passing the first heat exchanger and the second heat exchanger. Battery system heat recovery device. The inside of the storage tank is installed first heat exchange passages, the consumption for supplying water flowing into the first heat exchange passages, are warm through heat exchange with the heat exchange material, the heat storage tank The heat recovery device for a fuel cell system according to claim 2, wherein the heat recovery device is supplied to the hot water supply path from the fuel cell system. Inside the heat storage tank is installed a second heat exchange passages, the air-heating circulation water passing through the second heat exchange passages is being heated through heat exchange with the heat exchange material, the heat storage tank The heat recovery device for a fuel cell system according to claim 3, wherein the heat recovery device is supplied to the heating water supply path from the fuel cell system. A third heat exchanger for exchanging heat while passing the supply water for consumption or the circulating water for heating discharged from the heat storage tank; and an exothermic operation by an external control signal, to the third heat exchanger The heat recovery device for a fuel cell system according to claim 4, further comprising: a first auxiliary burner for supplying heat. The heat of the fuel cell system according to claim 5, further comprising: a temperature control valve in which the consumption supply water that has passed through the third heat exchanger and temperature adjustment water supplied from the outside flow in and are mixed. Recovery device. The heat recovery device of a fuel cell system according to claim 6, wherein the temperature control valve is a tempering valve type that mixes the consumption water supply and the temperature adjustment water using a temperature sensing operating element alloy. The circulating water for heating that has passed through the third heat exchanger is supplied to the outside so as to play a role of heating, and the circulating water for heating is recovered to the heat storage tank again.
A second three-way valve is installed on a piping path through which the circulating water for heating is collected in the heat storage tank, and the circulating water for heating is supplied to the heat storage tank by selective operation of the second three-way valve. The heat recovery device of the fuel cell system according to claim 5, wherein the heat recovery device is supplied to the outside through a by-pass path. A fourth heat exchanger that exchanges heat while passing the supply water for consumption discharged from the heat storage tank; and a second heat exchanger that generates heat by an external control signal and supplies heat to the fourth heat exchanger. An auxiliary burner;
A fifth heat exchanger that is installed separately from the fourth heat exchanger and exchanges heat while passing the circulating water for heating discharged from the heat storage tank; and an exothermic operation by an external control signal; The heat recovery apparatus for a fuel cell system according to claim 4, further comprising: a third auxiliary burner for supplying 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 water is supplied as the heat exchange material, and the water supply pipe is connected to the water supply pipe. 2. The heat recovery apparatus for a fuel cell system according to claim 1, wherein a solenoid valve for adjusting a supply amount of water as the heat exchange material is installed in conjunction with measurement data of the water level sensor.   2. The heat recovery apparatus for a fuel cell system according to claim 1, wherein a safety valve for lowering an internal pressure of the heat storage tank by the heat exchange material to a set overpressure condition or less is installed at an upper part of the heat storage tank.   2. The heat recovery apparatus for a fuel cell system according to claim 1, wherein a drain valve for discharging the heat exchange material to the outside as needed is installed at a lower portion of the heat storage tank.

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