KR102278267B1 - Energy recycling apparatus and method using groundwater of fuel cell system - Google Patents

Abstract

The present invention relates to an energy recycling apparatus and method using groundwater of a fuel cell system, in which the high-temperature hot water (energy) generated from the heat generated by a stack (power generation unit) of the fuel cell system is recovered and recycled by an integrated high-temperature recovery heat exchanger, thereby reducing a size of an entire system, eliminating the limitation of an installation space, reducing fuel costs due to reheating of a boiler. In addition, when hot water is not used, the system uses groundwater to cool the recovered hot water and supply back to the stack of the fuel cell system, so that the energy can recycled and operated without disposing of hot water. Accordingly, one or more fuel cell systems can be installed and interlocked with a high temperature recovery heat exchanger, a cooling heat exchanger, a hot water storage tank (or built-in heat exchange pipe), and a cooling water tank, which are disposed adjacent to each other. And, the heat exchangers, which are individually installed in the fuel cell system, can be installed in an integrated way, thereby reducing a size of the entire fuel cell system, recovering the heat generated by the fuel cell system (hot water) at high temperature, utilizing hot water, and saving boiler facility installation costs and fuel costs.

Description

Energy recycling apparatus and method using groundwater of fuel cell system

The present invention relates to an energy recycling device and method using groundwater in a fuel cell system, and in particular, by recovering hot water (energy) generated by heat generated from a stack (power generation unit) of a fuel cell system with an integrated high-temperature recovery heat exchanger. By recycling, the size of the entire system is reduced to eliminate the limitation of installation space, and the fuel cost due to reheating of the boiler is reduced. When the use of hot water (hot water) is low, it cools the recovered hot water using groundwater to restore the fuel cell system. It relates to an energy recycling apparatus and method using groundwater of a fuel cell system that allows energy to be recycled and operated without disposing of hot water by supplying it to a power generator (stack).

In general, a fuel cell system is a device for generating electrical energy using a fuel cell, and converts chemical energy of fuel into electrical energy using an electrochemical reaction. Such a fuel cell system reforms fuel into hydrogen gas in a desired state, sends it to a stack (power generation unit), introduces oxygen in the atmosphere, generates electricity through an electrochemical reaction, and generates heat.

The fuel cell system consists of a reforming unit that reforms fuel such as city gas into hydrogen, a stack (power generation unit) that produces electricity by an electrochemical reaction between reformed hydrogen and oxygen, and oxygen to lower the concentration of carbon monoxide generated during the reforming process. An air supply device for supplying the reforming unit and oxygen required to the stack unit, an exhaust system for exhausting the gas generated from the reforming unit to the outside air, water supplied to the steam reforming reaction process of the reforming unit and cooling water to maintain a constant temperature of the stack unit It is composed of a water tank for storage, an inverter that converts the power produced by the fuel cell stack into alternating current, and a number of peripheral devices (Balance of Plants) that perform start/stop/power generation status maintenance operation/control functions of the system.

As a prior art, the "fuel cell cogeneration system" of Korean Patent Publication No. 10-0807875 has been disclosed.

1 is a conceptual diagram of a product of a conventional fuel cell system, and shows a case in which the product of the prior art No. 10-0807875 is implemented. FIG. 2 is a conceptual diagram illustrating a case in which a plurality of fuel cell systems 10 are configured as a product application diagram of FIG. 1 .

Here, reference numeral 10 denotes a fuel cell system, 20 a reforming unit, 22 an air supply device, 24 an exhaust device, 30 a stack unit, 40 a water tank, and 42 a heat exchanger. Here, the reforming unit 20 , the stack unit 30 , and the heat exchanger 40 are all installed inside the fuel cell system 10 .

In addition, reference numeral 50 denotes a boiler, 52 denotes an auxiliary burner installed inside the boiler 50, 60 denotes a hot water storage tank, and 70 denotes a radiator. In FIG. 2, reference numeral 62 denotes a low-temperature water tank, 64 denotes a boiler hot water supply tank, 66 denotes a pressure reducing valve, and 68 denotes a pressurization pump.

According to this prior art (Registration Patent No. 10-0807875), the reforming unit 20 for reforming fuel inside the case of the fuel cell system 10, and the stack unit generating power by the electrochemical reaction of hydrogen and oxygen ( 30), an air supply device for supplying oxygen to the fuel cell system 10 through supply air, and a water tank having a heat exchanger 42 that performs a cooling function to maintain a constant temperature of the stack unit 30 ( 40), and a number of peripheral devices (Balance of Plants, BOP) (not shown in the drawing) that perform start/stop/power generation state maintenance operation/control functions of the system, and the like.

The water tank 40 for storing the waste heat recovered through the heat exchanger 42 as hot water is connected to a cooling water circulation pipe, and the exhaust passage connected to the exhaust device 24 for discharging the waste gas generated in the reforming process is provided with water. By combining the cylindrical heat exchanger 42 connected to the tank 40, it is possible to recover the heat of the waste gas.

In addition, when a plurality of fuel cell systems 10 are installed, the hot water storage tank 60 of FIG. 1 may be divided into a low temperature water tank 62 and a boiler hot water supply tank 64 as shown in FIG. 2 . In addition, an auxiliary burner 52 is installed inside the boiler 50 to additionally heat and supply hot water to the boiler hot water supply tank 64 of FIG. 2 , and an exhaust pipe for discharging waste gas generated from the auxiliary burner 52 . The heat of the waste gas can be recovered by coupling the cylindrical heat exchanger 42 of the water tank 40 to the furnace.

In addition, on the outside of the case of the fuel cell system 10 , a low-temperature water tank 62 , which is an auxiliary water tank connected in communication with a pipe for circulating hot water and a water tank 40 inside the case of the fuel cell system 10 , and boiler hot water supply The tank 64 is installed and the flow of hot water is controlled to recover the heat of the fuel cell system.

However, this prior art has the following problems.

That is, by configuring the heat exchanger 42 and the water tank 40 inside the case of one or more fuel cell systems 10 , the external size of the fuel cell system must be increased, and the manufacturing cost is increased.

In addition, heat generated in the stack unit 30 of the fuel cell system 10 is recovered, stored in the water tank 40, and then supplied as the cooling water of the stack unit 30, which is below the supplyable temperature of the cooling water. In order to store it as a furnace, the capacity must be large considering the season when hot water is used less. For this reason, about 1/2 of the size of the fuel cell system 10 is the size of the water tank 30 , and when several fuel cell systems 10 are installed, a large installation area is required.

In addition, the stack unit 30 of the fuel cell system 10 may be formed of a polymer electrolyte type. The polymer electrolyte stack unit 30 is mainly used for buildings or houses. In the case of such a polymer electrolyte type, the operating temperature is 25 ~ 80 °C, and the stack unit 30 is cooled to maintain a constant temperature to increase the power generation efficiency and maintain the performance for a long time. Here, the heat recovery method of the stack unit 30 supplies the water stored in the water tank 40 to the stack unit with a circulation pump, and the supplied water recovers the heat from the stack unit and circulates it to the water tank 40, and the fuel cell system The method of storing the water in the hot water storage tank 60 after recovering heat through the heat exchanger 42 built in the water tank 40 is used.

Since the water tank 40 supplied with the cooling water of the stack unit 30 cannot store water above the temperature that can be supplied as the cooling water of the stack unit 30, the temperature for recovering the heat is usually as low as 38 to 42°C. Therefore, in order to use hot water, it is used as hot water by second heating with the boiler 50.

In buildings and seasons that use less hot water, hot water is discharged to the stack unit 30 to lower the hot water temperature of the water tank 40 to a temperature that can cool the stack unit 30, and low-temperature make-up water is supplied to the water tank. As the cooling water is supplied to the stack unit 30 by lowering the temperature of the water supplied to the 40 , there is a limitation in that the hot water cannot be recycled and must be discharged. Typically, the temperature of the stack unit 30 is maintained at a constant temperature of 60 to 70°C, and the cooling water supply temperature of the stack unit 30 is supplied at 38 to 42°C.

In addition, the pressure of water supplied to the water tank 40 is proportional to the pressure used in the pipe of the building. Therefore, the stack unit 30 cannot withstand the pressure of the building piping of the water tank 40, so a pressure reducing valve 66 is installed at the inlet of the make-up water, and when the pressure is low, the hot water of the building cannot be supplied and additionally installed. It must be supplied to the building by increasing the pressure with one pressurizing pump (68). However, if the pressure is not lowered by using hot water, the pressure of the hot water supply pipe increases as a whole, and frequent failure of the pressure reducing valve 66 occurs. There is a problem in that the pressure of the cooling water is supplied, and thus the stack portion is damaged due to the high pressure of the cooling water.

The problems of the prior art will be described in more detail as follows.

First, after recovering heat from the heat of the stack part 30 of the fuel cell system 10 through the heat exchanger 42 built into the water tank 40 , the water inside the fuel cell system 10 . The structure is stored in the tank 40 and supplied with the cooling water of the stack unit 30. Since the heat cannot be recovered above the temperature that can be supplied as the cooling water, the recovery temperature is usually low to 38 ~ 42 ℃, and the recovered heat is discharged. Alternatively, secondary heating (55 to 60° C.) with the boiler 50 is used as hot water, so additional installation of a boiler is required.

Second, hot water is always generated during power generation of the fuel cell system. In buildings with little hot water usage and in the season when hot water usage is low, hot water recovered from heat recovery (Heat Recovery) must be discharged and supplied with low-temperature make-up water, so hot water is recycled. There is a problem of not being able to do it and releasing it.

Third, the fuel cell system 10 is a high-efficiency power generation system of 85 to 95% when including electricity generated during power generation and heat recovery, but a polymer electrolyte type (PEMFC) used for buildings or houses generates power. The efficiency is 35 to 38%, and the thermal efficiency is 50 to 55% higher than the power generation efficiency, and as described above, there is a disadvantage in that the economic efficiency is lowered due to the insufficient method of utilizing heat (hot water).

Fourth, the pressure of water supplied to the water tank 40 inside the fuel cell system 10 is the pressure used for the pipe of the building. As such, the water having the pressure of the building pipe passes through the water tank 40 to the stack unit ( When supplied to 30), the stack unit 30 may be damaged by pressure, so a pressure reducing valve 66 is installed at the inlet of the make-up water to reduce the pressure (usually 1 to 3 Kg/m2) that the stack unit 30 can withstand. had to supply Therefore, after the pressure of the make-up water is reduced (1 ~ 3Kg/m2), the heat of the stack unit 30 is recovered, and then the pressure must be increased by the pressurization pump 68 to supply the hot water of the building. Recently built buildings install the fuel cell system 10 in the underground machine room, and the natural head pressure of the building is high (about 5 ~ 10 Kg/m2), so the reduced pressure cannot be used as hot water in the building. The pressure is increased with the pump 68 and supplied to the building to use the hot water. However, if the hot water recovered from the exhaust heat is pressurized with the pressure pump 68 to supply the hot water supply pipe of the building, a high-pressure natural head pressure is always applied in the hot water supply pipe of the building, and for this reason, the hot water supply pipe of the building The pressure must be higher than the pressure applied inside. At this time, the hot water is used intermittently and intensively by the consumer, and if the consumer does not use it, the pressure of the overall piping system rises as much as the pressurized pump 68 is used, and the pressure reducing valve 66 malfunctions, and the pressure reducing valve 66. Due to the failure of the high-pressure make-up water, a phenomenon occurs in which the expensive stack part 30 is damaged. Equipment and switchboards necessary for a building are located on the basement floor and installed, but in order to prevent damage and failure of the fuel cell system, problems arise such as restrictions on the installation site that must be installed on the roof, where the natural head pressure is low.

In addition, the general fuel cell system and prior art have a disadvantage in that they cannot respond to the government's policies to promote the supply of new and renewable energy and the hydrogen economy in terms of industrial structure. For example, for buildings, it is necessary to increase the capacity of the fuel cell system and install it. In the current product, all equipment is built inside the case of the fuel cell system, so the external size of the fuel cell system is large, and a number of fuel cell systems are installed. When used, the components are duplicated for each product. Due to this, the product manufacturing cost increases, and in order to utilize heat (hot water) in the fuel cell system, the hot water storage tank that stores heat outside the fuel cell system, and the temperature of the hot water up to the temperature at which the heat from the fuel cell system can be used as hot water. There is a problem in that double costs occur because a boiler for reheating, a pump and piping for circulation, and a control unit are required.

Republic of Korea Patent No. 10-0807875

Therefore, the present invention has been proposed to solve the problems occurring in the general fuel cell system and the prior art as described above, and the high-temperature hot water (energy) generated in the stack (power generation unit) of a plurality of fuel cell systems is integrated into a high-temperature circuit. The purpose of providing an energy recycling device and method using the groundwater of a fuel cell system is to reduce the size of the entire system by recycling it with a receiving heat exchanger, thereby solving the limitation of the installation space and reducing the fuel cost due to the reheating of the boiler. There is this.

Another object of the present invention is to recycle energy without disposing of hot water by cooling the hot water recovered using groundwater and supplying it to the power generation unit (stack) of the fuel cell system when the utilization of hot water (hot water) in the fuel cell system is low. To provide an energy recycling device and method using the groundwater of a fuel cell system to be operated.

Another object of the present invention is to use the groundwater (leachate) generated in the basement as a coolant when the basement is dug deep for construction, thereby reducing the cost of disposing of groundwater and recycling the groundwater as energy. An object of the present invention is to provide an energy recycling device and method using groundwater in the system.

In order to achieve the above object, the "energy recycling apparatus using groundwater of a fuel cell system" according to the present invention includes one or more fuel cell systems that generate electric power by an electrochemical reaction of hydrogen and oxygen; a flow rate sensor for detecting a flow rate of hot water recovered from the stack portion of the one or more fuel cell systems; a high-temperature recovery heat exchanger for integrally recovering the high-temperature hot water output from the one or more fuel cell systems as energy; a hot water storage tank for storing the hot water recovered through the high temperature recovery heat exchanger and supplying the stored hot water as hot water; a cooling heat exchanger for supplying low-temperature water to the one or more fuel cell systems as a cooling water by secondary heat-exchanging water that has undergone primary heat exchange through the high-temperature recovery heat exchanger; a first circulation pump for supplying high-temperature hot water recovery water to recover high-temperature hot water from the high-temperature recovery heat exchanger; a cooling water tank for storing groundwater as cooling water for heat exchange supplied to the cooling heat exchanger; a second circulation pump supplying the cooling water stored in the cooling water tank to the cooling heat exchanger; an underground water tank supplying groundwater to the cooling water tank as cooling water; a third circulation pump for supplying the groundwater stored in the groundwater tank to the cooling water tank as a cooling water; a first temperature sensor for measuring the hot water temperature of the hot water storage tank; a second temperature sensor for measuring a temperature of the coolant supplied from the cooling heat exchanger to the fuel cell system; a third temperature sensor for measuring the temperature of the cooling water stored in the cooling water tank; It characterized in that it comprises a control unit for controlling the start and stop of the first to third circulation pumps based on the flow rate value detected by the flow rate sensor and the temperature value measured by the first to third temperature sensors, respectively. .

In the fuel cell system, a reforming unit for reforming fuel into hydrogen, a stack unit for generating electric power by an electrochemical reaction of hydrogen and oxygen reformed in the reforming unit, and the concentration of carbon monoxide generated during the reforming process in the reforming unit An air supply device for supplying oxygen to the reforming unit to lower it and supplying oxygen required to the stack unit, an exhaust device for exhausting the gas generated in the reforming unit to the outside air, water supplied to the steam reforming reaction process of the reforming unit, and A water tank that stores cooling water that maintains the temperature of the stack portion at a constant temperature, an upper portion is opened so that the pressure of the water inside becomes atmospheric pressure, and an inverter that converts power produced by the fuel cell stack of the stack portion into AC ,

In the above, the hot water storage tank is characterized in that a diffuser for forming a stratification for partitioning a hot layer and a low temperature layer of hot water is provided inside the tank.

The high-temperature hot water discharged from the fuel cell system is recycled as cooling water through the high-temperature recovery heat exchanger and the cooling heat exchanger in sequence, and is re-supplied to the fuel cell system to prevent energy waste by preventing hot water discharge. .

In the above, the cooling water tank includes a water level detection sensor for detecting the level of groundwater stored as cooling water,

When the water level detected by the water level detection sensor is equal to or higher than a preset level, the controller activates a fourth circulation pump that discharges the groundwater stored in the cooling water tank to the ground sewer, and discharges the ground water stored in the cooling water tank to the ground sewer. characterized in that

In order to achieve the above object, the "energy recycling method using groundwater of a fuel cell system" according to the present invention,

(a) When at least one fuel cell system is in operation in the control unit and hot water discharged from the fuel cell system is sensed through the flow rate sensor, the second temperature sensor TS-2 is used to re-supply to the fuel cell system Measuring the cooling water temperature (T2); (b) If the coolant temperature (T2) measured by the control unit is equal to or greater than a first preset value for controlling the start of the first circulation pump, the first circulation pump is started to recover the water stored in the hot water storage tank at a high temperature circulating in a heat exchanger; (c) measuring the hot water temperature (T1) of the hot water storage tank using the first temperature sensor in the control unit, and comparing the hot water temperature (T1) with the cooling water temperature (T2); (d) the controller stops the second circulation pump when the hot water temperature T1 is higher than the cooling water temperature T2 or the cooling water temperature is less than a second set value preset to control the start of the second circulation pump making; (e) in the controller, when the hot water temperature T1 is lower than the cooling water temperature T2 or the cooling water temperature is equal to or higher than the second set value, the second circulation pump is started to convert the groundwater stored in the cooling water tank into the cooling water. circulating in a heat exchanger for cooling; (f) measuring the cooling water temperature (T3) of the cooling water tank using a third temperature sensor in the control unit; (g) supplying the groundwater stored in the groundwater tank to the cooling water tank as cooling water by starting a third circulation pump when the cooling water temperature T3 measured by the control unit is equal to or greater than a third preset value; (h) if the cooling water temperature (T2) in the control unit is equal to or greater than the second set value and the cooling water temperature (T2) is higher than the cooling water temperature (T3), the third circulation pump is maintained to start, and the cooling water temperature ( and stopping the third circulation pump when T2) is less than the second set value and the cooling water temperature T2 is lower than the cooling water temperature T3.

In addition, the "energy recycling method using the groundwater of a fuel cell system" according to the present invention,

(i) the control unit measures the water level (WL) of the cooling water tank, and if the measured cooling water level is less than a preset level, the third circulation pump is started to store the groundwater stored in the groundwater tank as a cooling water in the cooling water tank and discharging the coolant stored in the coolant tank to a ground sewer by activating a fourth circulation pump when the coolant level is higher than or equal to the set level.

According to the present invention, at least one fuel cell system is installed, and a heat exchanger for high temperature recovery, a heat exchanger for cooling, a hot water storage tank (or built-in heat exchange pipe), a cooling water tank, and a refrigerator (condenser, evaporator) are arranged adjacent to each other. By interlocking with the fuel cell system, the size of the entire fuel cell system can be reduced by integrating heat exchangers installed individually in the fuel cell system, and heat (hot water) generated from the fuel cell system can be recovered at a high temperature to provide hot water supply. By using it as a water channel, it is possible to reduce the facility installation cost and fuel cost of the boiler.

In addition, in buildings that use less hot water and in the season when hot water is used less, the cost of discharging heat generated from the fuel cell system can be cooled with cooling water using groundwater and recycled to the fuel cell system, thereby saving energy. There is a positive effect (the electricity cost for cooling is reduced compared to the water and sewage charges due to discharge).

In addition, the underground water generated during basement construction is not immediately discharged into the underground sewer, but is stored as cooling water and used to cool the high-temperature hot water recovered from the fuel cell system, thereby recovering heat by using tap water as cooling water. It has the effect of reducing the cost of discharging hot water to a sewer pipe and reducing the cost of generating cooling water by using groundwater as cooling water.

In addition, from an industrial structural point of view, only essential parts such as the reforming unit, stack unit, inverter, and control device necessary for fuel cell system operation are composed inside the fuel cell system case, and external components such as a water tank are integrated to provide external components. By implementing it, there is an effect of reducing the manufacturing cost of the fuel cell system and making the product smaller in size.

In addition, from a technical point of view, in the case of the polymer electrolyte type, which is a type mainly used for buildings or houses, the operating temperature is 25 ~ 80℃, and the stack part uses a catalyst in the separator with a thickness of nanoparticles, and hydrogen during power generation. Reaction heat is generated as the oxidation and reduction actions are repeatedly and continuously carried out through the chemical reaction of oxygen and oxygen. Accordingly, in the present invention, a cooling unit for maintaining a constant temperature by circulating water is provided in the stack unit, and the temperature of the water supplied to the cooling unit is supplied to a temperature that can be cooled (38 ~ 42 ℃) or less to keep the temperature of the stack unit constant ( Usually 60 ~ 70 ℃), it is possible to increase the power generation efficiency by generating power. In addition, when a high temperature is supplied to the stack part, the efficiency decreases and performance cannot be maintained for a long time due to the phenomenon that the platinum catalyst is ionized at a high temperature or separated from the separator. It is possible to maintain a constant temperature of the stack portion, and since the pressure of water is not reduced by the pressure reducing valve, there is no need to use a pressurization pump, etc., so that damage of the stack portion due to high pressure can be prevented.

That is, in the present invention, since the water tank inside the fuel cell system case is manufactured in an open structure and does not reduce the pressure of water by using a pressure reducing valve, there is no need for a pressurization pump, and the fuel cell system is capable of reducing the pressure of hot water and municipal water in a building. Since it is operated separately, no pressure is applied to the stack, damage to the fuel cell system can be fundamentally prevented.

In addition, the fuel cell system requires water in the steam reforming method not only to supply cooling water to the stack but also to the reforming unit. According to the present invention, water is supplied to the stack unit and the reforming unit at atmospheric pressure from the open type water tank for cooling, so that various water pressures of high-rise buildings There is also the advantage that it can be applied irrespective of the

In addition, the heat generated in the fuel cell system stack unit is primarily recovered as a heat exchanger for high-temperature recovery, and the temperature of the hot water circulated in the lower layer of the hot water storage tank in the building where the consumer uses a small amount of hot water and in the season when the amount of hot water consumption is small. The temperature is higher than the temperature to be supplied as cooling water to the stack part of the fuel cell system because heat exchange is not performed due to the high temperature. At this time, it is possible to maintain the performance and efficiency of the stack part and extend the durability life by supplying the fuel cell system array to the cooling heat exchanger with cooling water using groundwater to cool the high-temperature hot water to the stack part and supply it to the stack part at a stable temperature. There are also advantages.

In addition, heat generated in the fuel cell system stack is recovered with a high-temperature recovery heat exchanger, introduced into the upper part of the hot water storage tank to form a thermal layer, and the hot water is stored at a temperature (55 to 60) that can be used immediately as hot water. ℃), so that hot water can be used without additional heating of the boiler, there is no need to install a boiler, so there are various effects that can save boiler facility costs, reduce boiler fuel costs, and increase the utilization of heat in the fuel cell system.

1 is a product configuration diagram of a conventional fuel cell system;
FIG. 2 is an application view of a case in which a plurality of fuel cell systems are configured as a product application diagram of FIG. 1;
3 is a block diagram of a fuel cell system according to a preferred embodiment of the present invention;
4 is a configuration diagram of an embodiment of an energy recycling device using groundwater of a fuel cell system to which FIG. 3 is applied;
5 is a flowchart illustrating an energy recycling method of a fuel cell system according to a preferred embodiment of the present invention.

Hereinafter, an apparatus and method for recycling energy using groundwater in a fuel cell system according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The terms or words used in the present invention described below should not be construed as being limited to conventional or dictionary meanings, and the inventor may appropriately define the concept of terms in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, so various equivalents and It should be understood that there may be variations.

First, the present invention installs at least one fuel cell system in which a reforming unit, a stack unit (power generation unit), an air supply device, an exhaust device, an inverter, a water tank, and a plurality of peripheral devices (BOP) are accommodated in a case, and , by connecting heat exchangers for high temperature recovery, cooling heat exchangers, hot water storage tanks, cooling water tanks, pumps, and pipes arranged adjacent to each other and installing heat exchangers installed individually for each fuel cell system in an integrated manner, cost reduction and case size has been reduced

In addition, hot water (heat) generated from the fuel cell system can be recovered at a high temperature so that it can be used as hot water, thereby reducing fuel costs for boilers. After discharging the waste, it uses groundwater without supply of tap water to efficiently cool the waste heat and recycle it to the fuel cell system, thereby maintaining high performance, extending the lifespan and improving economic feasibility.

In addition, the underground water generated during basement construction is not immediately discharged into the ground sewer, but is stored as cooling water and used to cool the high-temperature hot water recovered from the fuel cell system, thereby recovering heat by using tap water as cooling water. The cost of discharging hot water to the sewage system was reduced, and the cost of generating a separate cooling water by using groundwater as cooling water was also reduced.

A more detailed explanation of this is as follows.

3 is a block diagram of a fuel cell system 100 according to an embodiment of the present invention, and is a reforming unit 110 , an air supply unit 130 , an exhaust unit 140 , and a stack unit (power generation unit) 120 . , a water tank 150 and an inverter 160 may be included.

The reformer 110 reforms fuel (eg, city gas, etc.) into hydrogen in the fuel cell system 100 that generates electric power by an electrochemical reaction between hydrogen and oxygen.

The power generation unit, the stack unit 120 , generates electric power by an electrochemical reaction between hydrogen and oxygen reformed in the reforming unit 110 .

The air supply device 130 supplies oxygen to the reformer 110 in order to lower the concentration of carbon monoxide generated during the reforming process in the reformer 110 , and supplies oxygen required to the stack unit 120 .

The exhaust device 140 exhausts the gas generated in the reforming unit 110 to the outside air.

The water tank 150 supplies and stores water supplied to the steam reforming process of the reforming unit 110 and cooling water that maintains the temperature of the stack unit 120 at a constant temperature, and the upper part is opened so that the pressure of water inside is to atmospheric pressure.

The inverter 160 converts power generated in the fuel cell stack of the stack unit 120 into AC.

The installation structure and operation method of the fuel cell system 100 will be briefly described as follows.

First, the water tank 150 inside the case of the fuel cell system 100 is of an open type and has a small cross-sectional area and a long structure, so that the water level in the pump P that circulates from the water tank 150 to the stack unit 120 is Since there is no shortage, idling of the pump P is prevented, and the pressure of the water tank 150 is maintained at atmospheric pressure even when the high make-up water pressure of the building is not reached.

Second, the high-temperature hot water generated by the heat recovered from the stack unit 120 of one or more fuel cell systems 100 is first passed through a heat exchanger 210 for high-temperature recovery, which will be described later, in a pipe bundled with heat, Second, through the cooling heat exchanger 220 , heat is emitted to a temperature at which the cooling water can be re-supplied to the stack unit 120 of the fuel cell system 100 to the water tank 150 of each fuel cell system 100 . supply As a result, the heat (hot water) discharged from the fuel cell system is cooled to an appropriate temperature and recycled, thereby preventing energy waste. Here, the heat generated after power generation in the fuel cell system (hot water) is called “energy”.

4 is a block diagram of an energy rehabilitation apparatus using groundwater of the fuel cell system to which FIG. 3 is applied.

A flow rate sensor (A) that detects a flow rate flowing through a pipe integrating the high-temperature hot water recovered from the stack unit 120 of one or more fuel cell systems (100 - 100+N), the fuel cell system (100 - 100) The high temperature recovery heat exchanger 210 that integrates and recovers the high temperature hot water discharged from the internal water tank 150 of +N as energy, and stores the high temperature hot water recovered through the high temperature recovery heat exchanger 210, , the hot water storage tank 310 for supplying the stored hot water as hot water supply water, and the second heat exchange of water that has undergone primary heat exchange through the high temperature recovery heat exchanger 210 to exchange low temperature water with the one or more The cooling heat exchanger 220 for supplying cooling water to the fuel cell system 100 - 100+N, and a first circulation pump for supplying high-temperature hot water recovery water to recover the high-temperature hot water from the high-temperature recovery heat exchanger 210 (P-1), a cooling water tank 410 for storing groundwater as cooling water for heat exchange supplied to the cooling heat exchanger 220, and cooling water stored in the cooling water tank 410 to the cooling heat exchanger 220 A second circulation pump (P-2) for supplying, a groundwater tank 420 for supplying groundwater to the cooling water tank 410 as cooling water, and groundwater stored in the groundwater tank 420 as cooling water to the cooling water tank 410 The fuel cell system 100 in the third circulation pump P-3 to supply, the first temperature sensor TS-1 measuring the hot water temperature of the hot water storage tank 310, and the cooling heat exchanger 220 - 100+N) a second temperature sensor (TS-2) for measuring the temperature of the cooling water supplied, a third temperature sensor (TS-3) for measuring the temperature of the cooling water stored in the cooling water tank (410), the flow rate Based on the flow rate value detected by the detection sensor (A) and the temperature value measured by the first to third temperature sensors (TS-1 - TS3), the first to third circulation pumps (P-1 - P-) 3) includes a control unit 500 for controlling the start and stop.

The hot water storage tank 310 is provided with a diffuser for forming a stratification that partitions a hot layer and a low temperature layer of hot water inside the tank.

The cooling water tank 410 includes a water level detection sensor 411 that detects a water level of groundwater stored as cooling water, and the control unit 500 sets the water level detected by the water level detection sensor 411 to a preset level. If this is the case, the fourth circulation pump P-4 that discharges the underground water stored in the cooling water tank 410 to the ground sewer is activated to discharge the ground water stored in the cooling water tank 410 to the ground sewer.

The fuel cell system 100 - 100+N applied to FIG. 4 is the same as the configuration of the fuel cell system 100 shown in FIG. 3, and the operation is also the same.

The operation of the energy recycling device using the groundwater of the fuel cell system according to the present invention configured as described above will be described in detail as follows.

The capacity of the hot water storage tank 310 installed outside the fuel cell system is determined and installed in consideration of the installed capacity of the fuel cell system (100 - 100+N) and the hot water supply load of the building. The hot water storage tank 310 is manufactured in a cylindrical vertical shape, and the upper part is provided with a hot water storage part based on the middle part, and the lower part is a low temperature hot water storage part. In the direction, at the end of the pipe connected to the lower part, a diffuser is installed in the lower direction to achieve a temperature stratification.

Here, since the configuration and operation of each fuel cell system 100 - 100+N are the same, only one fuel cell system (eg, 100) will be described as an example.

The heat (hot water) generated in the stack unit 120 of the fuel cell system 100 is recovered at a high temperature by starting the first circulation pump (P-1) of the low temperature water located at the lower side of the hot water storage tank 310 . The heat is primarily recovered by circulation through the heat exchanger 210 and stored in the upper high temperature part of the hot water storage tank 310 to be used as hot water.

If the temperature that can be used as the coolant of the fuel cell system 100 is higher than the temperature that can be used as the coolant of the fuel cell system 100 even after the first heat recovery from the high temperature recovery heat exchanger 210 (determined based on the temperature of the second temperature sensor TS-2), the controller The cooling water at the lower side of the cooling water tank 410 is circulated to the cooling heat exchanger 220 by the second circulation pump P-2 under the control of 500 to recover heat again. By this operation, the water supplied to the stack unit 120 of the fuel cell system 100 is supplied to the water tank 150 in the case of the fuel cell system 100 as water at a stable temperature that can be used as cooling water.

The cooling water tank 410 is installed by determining the capacity and specification in consideration of the capacity of the fuel cell system 100 installed at least one or more, the load of hot water supply in the building, and the amount of hot water used according to the season. The cooling water tank 410 is installed at a close distance to the cooling heat exchanger 220, and according to the set value of the cooling water tank 410 and the attached third temperature sensor TS-3, the third circulation pump P-3 control the operation of

In addition, the cooling water stored in the cooling water tank 410 uses groundwater obtained through basement construction. Groundwater generated during basement construction is stored in the groundwater tank 420 . By storing the groundwater generated in the underground layer in the groundwater tank 420 instead of using it immediately, the filth of the groundwater that is the leachate can be filtered and used in the groundwater tank 420 to some extent. If necessary, by filtering out foreign substances using a filter or the like, it is also possible to prevent a failure of equipment such as a motor due to clogging of pipes and the like due to foreign substances. There is no problem with the system even if the groundwater generated from the basement construction is directly used without using a filter or the like.

A water level detection sensor 411 for measuring the level of the cooling water, which is groundwater, is built in the cooling water tank 410 to detect the level of the groundwater in the cooling water tank 410 in real time. The detected coolant level information is transmitted to the controller 500, and the controller 500 compares the delivered coolant level with a set level, and when the coolant level is higher than or equal to the set level, the fourth circulation pump (P-4) to discharge the cooling water (underground water) stored in the cooling water tank 410 to the sewage on the ground. Accordingly, an appropriate amount of groundwater is stored in the cooling water tank 410 .

In recent downtown buildings, high-rise buildings are being built by applying a high floor area ratio to a narrow space due to reasons such as population density. For this reason, in proportion to the height of the building above the ground, the basement is dug deep and a parking lot and a machine room are installed to use the basement floor effectively. At this time, if the basement is dug deep, groundwater (leachate) is generated in the basement.

In addition, in the metropolitan area, due to the intersection of subway and high-speed train lines, the depth of subway and high-speed train stations and tracks is gradually dug underground, and groundwater (leachate) is generated in the basement.

For this reason, the outer wall in contact with the soil and sand in the basement must be reinforced a lot to withstand the earth pressure, and the groundwater on the soil side must be introduced into the building from the lowest part of the basement floor to safely support the building.

Currently, the groundwater (leachate) generated from the soil and sand is introduced into the building from the lowest part of the building, stored in the groundwater inflow tank, and discharged to the ground sewer with a pump.

Also, in the Cheonggyecheon section, which is a part of Seoul, groundwater is stored in an inflow tank and discharged upstream of the Cheonggyecheon by a pump to be used as a park for the convenience of citizens. are stocked in

Here, according to the city's water and sewerage rates, 400 won per cubic meter of discharged underground water is incurred.

Therefore, in the present invention, as described above, the underground water generated during the construction of the basement is not immediately discharged into the sewer above the ground, but is utilized as a cooling water to recover the energy of the fuel cell system 100 .

That is, the groundwater, which is the cooling water stored in the cooling water tank 410 , circulates the cooling heat exchanger 220 through the second circulation pump P-2 and is recovered to the cooling water tank 410 again. At this time, the cooling heat exchange The hot water (array) of the fuel cell system 100, which has undergone primary heat exchange in the high-temperature recovery heat exchanger 210 in the unit 220, is exchanged with the groundwater to lower the temperature to an appropriate temperature for use in the fuel cell system 100. It is supplied to the fuel cell system 100 .

The temperature of the groundwater varies depending on the depth and season, but in general, the water temperature is maintained at 10 - 18 ℃ at about 50 - 100 m underground during the four seasons.

As such, the groundwater treatment cost can be reduced by recycling the groundwater generated during the basement construction for the purpose of recovering the energy of the fuel cell system by using it as cooling water instead of directly discharging it to the sewage system above the ground. Electric energy wasted for discharging, dissipating, and cooling the tap water used for this purpose can also be saved.

In addition, a supply nozzle (N-1) for supplying make-up water to the lower portion of the hot water storage tank 310, a high-temperature recovery heat exchanger 220 and a first circulation pump (P-1) at a position slightly lower than the middle of the tank Heat generated in the stack unit 120 of the fuel cell system 100 is recovered from the supply nozzle (N-3) supplied to the On the uppermost layer of the supply nozzle (N-4) and the hot water storage tank 310 for introducing high temperature into the hot water storage tank 310, the arrangement of the fuel cell system 100 can be directly used as hot water (55 ~ 60 ℃). ) is attached to the supply nozzle (N-2) for supplying.

In addition, a first circulation pump (P-1) is installed in the pipe connected to the heat exchanger 210 for high temperature recovery from the lower side of the hot water storage tank 310, and heat is transferred by flowing the heat exchanger 210 for high temperature recovery. The recovered hot water is introduced into the upper part of the hot water storage tank 310, and a diffuser is provided on the pipe inside the tank connected to the lower part of the tank in the lower side direction, and the pipe inside the tank connected to the upper part of the tank has a diffuser in the upper direction. make up

In addition, a second circulation pump (P-2) is installed in the pipe connected to the cooling heat exchanger 220 from the lower side of the cooling water tank 410, and the heat is recovered by flowing the cooling heat exchanger 220. The cooling water flows into the upper portion of the cooling water tank 410 . As a result, heat is emitted to the water tank 150 of the fuel cell system 100 to a temperature that can be supplied to the cooling water of the stack unit 120 , and cooling water at a stable temperature is supplied.

5 is a flowchart illustrating an energy recycling method using groundwater in a fuel cell system according to an embodiment of the present invention.

As shown in this figure, in the method for recycling energy using groundwater of a fuel cell system according to the present invention, (a) at least one fuel cell system (100 - 100+N) is in operation in the control unit 500 and a flow rate sensor ( When hot water discharged from the fuel cell system 100 - 100+N is detected through A), the second temperature sensor TS-2 is used to re-supply to the fuel cell system 100 - 100+N. Steps (S101 - S104) of measuring the cooling water temperature (T2), (b) the cooling water temperature (T2) measured by the control unit (500) is set in advance to control the start of the first circulation pump (P-1) If it is equal to or greater than 1 set value, starting the first circulation pump (P-1) to circulate the water stored in the hot water storage tank 310 to the high temperature recovery heat exchanger 210 (S105 - S106), (c) the above The control unit 500 measures the hot water temperature T1 of the hot water storage tank 310 using the first temperature sensor TS-1, and compares the hot water temperature T1 with the cooling water temperature T2 (S108). , S110), (d) in the controller 500, the hot water temperature (T1) is higher than the cooling water temperature (T2) or the cooling water temperature (T2) to control the start of the second circulation pump (P-2) Step (S109) of stopping the second circulation pump (P-2) if it is less than a second set value preset for this purpose (S109), (e) the hot water temperature (T1) in the control unit 500 is lower than the cooling water temperature (T2) Or, when the cooling water temperature T2 is equal to or greater than the second set value, the second circulation pump P-2 is activated to circulate the groundwater stored in the cooling water tank 410 to the cooling heat exchanger 220 as cooling water. Steps (S111), (f) measuring the coolant temperature T3 of the coolant tank 410 using the third temperature sensor TS-3 in the controller 500 (S112), (g) the controller If the coolant temperature T3 measured in 500 is equal to or greater than the third preset value, the third circulation pump P-3 is started to convert the groundwater stored in the groundwater tank 420 into the coolant tank ( 410) in the steps (S113 - S114), (h) when the cooling water temperature T2 in the control unit 500 is equal to or greater than the second set value and the cooling water temperature T2 is higher than the cooling water temperature T3 Maintaining the start of the third circulation pump P-3, and when the coolant temperature T2 is less than the second set value and the coolant temperature T2 is lower than the coolant temperature T3, the third circulation and stopping the pump (P-3) (S118 - S119).

In addition, in the "energy recycling method using groundwater of a fuel cell system" according to the present invention, (i) the control unit 500 measures the water level (WL) of the cooling water tank 410, and the measured cooling water level is If it is less than the preset level, the third circulation pump (P-3) is activated to store the groundwater stored in the groundwater tank 420 as the cooling water in the cooling water tank 410, and if the cooling water level is above the set level, the fourth It may include a step (S115 - S117) of starting the circulation pump (P-4) and discharging the coolant stored in the coolant tank (410) to the ground sewer.

The energy recycling method using the groundwater of the fuel cell system according to an embodiment of the present invention configured as described above will be described in detail as follows.

First, in a situation where the fuel cell system 100 does not operate, the first to fourth circulation pumps P-1 to P-4 are stopped (S102), and when power generation is started by the operation of the fuel cell system 100 , (S101), the control unit 500 controls the circulation of water through the flow rate sensor (A) that detects the circulation of water in the pipe bundled with the high-temperature hot water recovered from the stack unit 120 of one or more fuel cell systems 100 . Detect (S103). At this time, when the circulation of water is sensed, the first circulation pump P-1 is started and the high temperature arrangement of the stack unit 120 of the fuel cell system 100 is transferred to the high temperature recovery heat exchanger 210 and the cooling heat exchanger 220 . ), the low-temperature water that has released heat is moved to the water tank 150 built in the fuel cell system 100 . The low-temperature water stored in the water tank 150 is circulated to the stack unit 120 of the fuel cell system 100 by the circulation pump P to supply cooling water at a stable temperature. The low-temperature water in the middle lower portion of the hot water storage tank 310 is circulated to the high-temperature recovery heat exchanger 210 to recover the high-temperature heat from the stack unit 120 of the fuel cell system 100, and the hot water storage tank 310 It is stored and used as hot water. When it is detected that there is no water circulation in the flow rate sensor (A) attached to the pipe connected to the heat exchanger 210 for high temperature recovery of the heat generated in one or more fuel cell systems 100 , the first circulation pump P-1 ) stops.

Next, the coolant temperature T2 supplied to the fuel cell system 100 is measured (S104), and the measured coolant temperature T2 is used in advance to control the start of the first circulation pump P-1. If it is greater than or equal to the first set value, the first circulation pump (P-1) is started (S105 - S106).

Next, the hot water temperature T1 measured by the first temperature sensor TS-1 installed in the hot water storage tank 310 and the second temperature sensor TS-2 attached to the pipe supplied to the water tank 150 The cooling water temperature T2 is compared (S107, S108, S110). At this time, if the hot water temperature (T1) is higher than the cooling water temperature (T2) or the cooling water temperature (T2) is less than the second set temperature (normally 38 ~ 42 ℃), move to step S109 to the second circulation pump (P-2) to stop On the other hand, if the coolant temperature T2 is higher than the hot water temperature T1 or the coolant temperature T2 is equal to or higher than the second set temperature, the second circulation pump P-2 connected to the cooling heat exchanger 220 is started. The low-temperature water in the cooling water tank 310 is passed through the cooling heat exchanger 220 to cool the heat recovered from the fuel cell system 100 to the water tank 150 inside the fuel cell system 100. supply (S111).

Next, when the temperature value T3 of the third temperature sensor TS-3 attached to the cooling water tank 410 is equal to or greater than the third set temperature (normally 30 to 35° C.), the cooling water tank 410 and the underground water tank 420 ) to start the third circulation pump (P-3) connected between ) and stored in the cooling water tank 410 (S112 - S114).

Next, the cooling water temperature T3 of the third temperature sensor TS-3 of the cooling water tank 410 and the temperature value T2 of the second temperature sensor TS-2 attached to the pipe supplied to the water tank 150 ), when the temperature value of the third temperature sensor (TS-3) of the cooling water tank 410 is small or the water is cooled to a set temperature (usually 15 ~ 20 ℃), the third circulation pump (P-3) to stop (S118 - S119).

In addition, the temperature T1 of the first temperature sensor TS-1 installed in the hot water storage tank 310 and the temperature T2 of the second temperature sensor TS-2 attached to the pipe supplied to the water tank 150 ), or when the temperature value (T2) of the second temperature sensor (TS-2) is the set temperature (normally 38 ~ 42 ℃), the first circulation pump (P) connected to the high temperature recovery heat exchanger 210 -1) stops the start.

On the other hand, the water level (WL) of the cooling water tank 410 is measured, and if the measured cooling water level is less than a preset level, the third circulation pump P-3 is started to convert the groundwater stored in the groundwater tank 420 into cooling water. is stored in the coolant tank 410, and when the coolant level is above the set level, the fourth circulation pump P-4 is activated to discharge the coolant stored in the coolant tank 410 to the ground sewer (S115). - S117).

As described above, the present invention installs one or more fuel cell systems in which a reformer, a stack, an air supply device, an inverter, a water tank, and a plurality of peripheral devices (BOP) are accommodated inside the case, and the high temperature is adjacent to the mutual fuel cell system. By connecting a heat exchanger for recovery, a heat exchanger for cooling, a hot water storage tank (or a hot water storage tank with a built-in heat exchange pipe), a cooling water tank, a pump, and a pipe, the heat exchanger installed individually for each fuel cell system is integrated. Cost reduction and system size can be reduced.

In addition, since hot water generated in the fuel cell system can be recovered at a high temperature, it can be used as hot water, thereby reducing the fuel cost of the boiler due to secondary heating.

In addition, the hot water generated by one or more fuel cell systems is continuously operated without discharging in buildings with low hot water consumption and in seasons with low hot water consumption by using underground water, cooling water tanks, and cooling heat exchangers in an array in which one or more fuel cell systems are installed. By generating power, the efficiency of the fuel cell system is increased.

In particular, the underground water generated during basement construction is not immediately discharged into the underground sewer system, but is stored as cooling water and used to cool the high-temperature hot water recovered from the fuel cell system, thereby recovering heat by using tap water as a cooling water. It is possible to reduce the cost of discharging hot water to the sewer, and to reduce the cost of generating a separate cooling water by using groundwater as cooling water.

Although the invention made by the present inventor has been described in detail according to the above embodiment, the present invention is not limited to the above embodiment, and it is common knowledge in the art that various changes can be made without departing from the gist of the present invention. self-evident to those who have

100 - 100+N: fuel cell system
110: reforming unit
120: stack unit
130: exhaust device
140: air supply
150: water tank
160: inverter
210: heat exchanger for high temperature recovery
220: heat exchanger for cooling
310: hot water storage tank
410: coolant tank
420: groundwater tank

Claims (6)

one or more fuel cell systems that generate electric power by an electrochemical reaction of hydrogen and oxygen; a flow rate sensor for detecting a flow rate of hot water recovered from the stack portion of the one or more fuel cell systems; a high-temperature recovery heat exchanger for integrally recovering the high-temperature hot water output from the one or more fuel cell systems as energy; a hot water storage tank for storing the hot water recovered through the high temperature recovery heat exchanger and supplying the stored hot water as hot water; a cooling heat exchanger for supplying low-temperature water to the one or more fuel cell systems as a cooling water by secondary heat-exchanging water that has undergone primary heat exchange through the high-temperature recovery heat exchanger; a first circulation pump for supplying high-temperature hot water recovery water to recover high-temperature hot water from the high-temperature recovery heat exchanger; a cooling water tank for storing groundwater as cooling water for heat exchange supplied to the cooling heat exchanger; a second circulation pump supplying the cooling water stored in the cooling water tank to the cooling heat exchanger; a groundwater tank storing groundwater and supplying the groundwater stored in the cooling water tank as cooling water; a third circulation pump for supplying the groundwater stored in the groundwater tank to the cooling water tank as a cooling water; a first temperature sensor for measuring the hot water temperature of the hot water storage tank; a second temperature sensor for measuring a temperature of the coolant supplied from the cooling heat exchanger to the fuel cell system; a third temperature sensor for measuring the temperature of the cooling water stored in the cooling water tank; and a control unit for controlling starting and stopping of the first to third circulation pumps based on the flow rate value detected by the flow rate sensor and the temperature value measured by the first to third temperature sensors, respectively,
The control unit is
When at least one fuel cell system is in operation and hot water discharged from the fuel cell system is sensed through the flow rate sensor, the temperature T2 of the cooling water supplied back to the fuel cell system is measured using the second temperature sensor. and, when the measured cooling water temperature T2 is equal to or greater than a first set value preset to control the start of the first circulation pump, the first circulation pump is started and the water stored in the hot water storage tank is circulated to the heat exchanger for high temperature recovery. and measure the hot water temperature (T1) of the hot water storage tank using the first temperature sensor, compare the hot water temperature (T1) and the cooling water temperature (T2), and the hot water temperature (T1) is the cooling water temperature (T2) ) or the cooling water temperature is less than a second set value preset to control the start of the second circulation pump, the second circulation pump is stopped, and the hot water temperature (T1) is lower than the cooling water temperature (T2) or When the cooling water temperature is equal to or greater than the second set value, the second circulation pump is started to circulate the groundwater stored in the cooling water tank to the cooling heat exchanger as cooling water, and the cooling water temperature of the cooling water tank (T3) using the third temperature sensor. ), and if the measured coolant temperature (T3) is equal to or greater than the third preset value, the third circulation pump is started to supply the groundwater stored in the groundwater tank to the coolant tank as coolant, and the coolant temperature (T2) is If the second set value or more and the cooling water temperature T2 is higher than the cooling water temperature T3, the third circulation pump is maintained, and the cooling water temperature T2 is less than the second set value and the cooling water temperature When (T2) is lower than the coolant temperature (T3), the third circulation pump is stopped, the water level (WL) of the coolant tank is measured, and if the measured coolant level is less than a preset level, the third circulation pump to store the groundwater stored in the groundwater tank as cooling water in the cooling water tank, and when the cooling water level is above the set level, the fourth circulation pump is activated to discharge the cooling water stored in the cooling water tank to the ground sewer. doing An energy recycling device using groundwater from a fuel cell system.
The method according to claim 1, The fuel cell system is a reforming unit for reforming fuel into hydrogen, a stack unit for generating electric power by an electrochemical reaction of hydrogen and oxygen reformed in the reforming unit, carbon monoxide generated in the reforming process in the reforming unit An air supply device for supplying oxygen to the reforming unit and supplying oxygen required to the stack unit in order to lower the concentration of an exhaust unit exhausting the gas generated in the reforming unit to the outside air, and supplying to the steam reforming reaction process of the reforming unit A water tank that stores water and cooling water that maintains the temperature of the stack part at a constant temperature, the upper part is opened so that the pressure of the water inside becomes atmospheric pressure, and an inverter that converts electric power produced by the fuel cell stack of the stack part into alternating current including,
The hot water storage tank is an energy recycling device using groundwater of a fuel cell system, characterized in that a diffuser for forming a stratification for partitioning a high temperature layer and a low temperature layer of hot water is provided in the tank.
The method according to claim 1, wherein the high-temperature hot water discharged from the fuel cell system is recycled as cooling water through the heat exchanger for high-temperature recovery and the heat exchanger for cooling in sequence, and re-supplied to the fuel cell system to prevent energy waste by preventing the discharge of hot water. An energy recycling device using groundwater of a fuel cell system.
The method according to claim 1, wherein the cooling water tank comprises a water level detection sensor for detecting the level of the groundwater stored as cooling water,
When the water level detected by the water level detection sensor is equal to or higher than a preset level, the controller activates a fourth circulation pump that discharges the groundwater stored in the cooling water tank to the ground sewer, and discharges the ground water stored in the cooling water tank to the ground sewer An energy recycling device using groundwater of a fuel cell system, characterized in that
A method of recycling energy of a fuel cell system using the energy recycling device using the groundwater of the fuel cell system according to any one of claims 1 to 4,
(a) When at least one fuel cell system is in operation in the control unit and hot water discharged from the fuel cell system is sensed through the flow rate sensor, the second temperature sensor TS-2 is used to re-supply to the fuel cell system Measuring the cooling water temperature (T2);
(b) If the coolant temperature (T2) measured by the control unit is equal to or greater than a first preset value for controlling the start of the first circulation pump, the first circulation pump is started to recover the water stored in the hot water storage tank at a high temperature circulating in a heat exchanger;
(c) measuring the hot water temperature (T1) of the hot water storage tank using the first temperature sensor in the control unit, and comparing the hot water temperature (T1) with the cooling water temperature (T2);
(d) the controller stops the second circulation pump when the hot water temperature T1 is higher than the cooling water temperature T2 or the cooling water temperature is less than a second set value preset to control the start of the second circulation pump making;
(e) in the controller, when the hot water temperature T1 is lower than the cooling water temperature T2 or the cooling water temperature is equal to or higher than the second set value, the second circulation pump is started to convert the groundwater stored in the cooling water tank into the cooling water. circulating in a heat exchanger for cooling;
(f) measuring the cooling water temperature (T3) of the cooling water tank using a third temperature sensor in the control unit;
(g) supplying the groundwater stored in the groundwater tank to the cooling water tank as cooling water by starting a third circulation pump when the cooling water temperature T3 measured by the control unit is equal to or greater than a third preset value; and
(h) if the cooling water temperature (T2) in the control unit is equal to or greater than the second set value and the cooling water temperature (T2) is higher than the cooling water temperature (T3), the third circulation pump is maintained to start, and the cooling water temperature ( and stopping the third circulation pump when T2) is less than the second set value and the cooling water temperature T2 is lower than the cooling water temperature T3. recycling method.
The method according to claim 5, (i) The control unit measures the water level (WL) of the cooling water tank, and if the measured cooling water level is less than a preset level, the third circulation pump is started to convert the groundwater stored in the groundwater tank into the cooling water. Storing the coolant in a coolant tank, and activating a fourth circulation pump when the coolant level is higher than or equal to the set level to discharge the coolant stored in the coolant tank to the groundwater of the fuel cell system, further comprising: Energy recycling method.

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