Fuel cell cogeneration system

Abstract

The utility model discloses a fuel cell heat and power cogeneration system which comprises a fuel cell engine, the fuel cell engine comprises an electric pile, the electric pile is provided with a power generation electric energy output line and a cooling pipeline, the cooling pipeline is provided with a cooling water inlet and a cooling water outlet, and the power generation electric energy output line is sequentially provided with a DC / DC converter and a shunt. The shunt divides the circuit into two paths, one path is a low-voltage line, the other path is a high-voltage line, the low-voltage line is used for supplying power to electric parts in the fuel cell engine after voltage reduction, and the high-voltage line is used for being connected with a power grid or supplying power to a local load; the cooling water inlet and the cooling water outlet are respectively connected to an inlet and an outlet on one side of the plate heat exchanger; an inlet and an outlet in the other side of the plate heat exchanger are connected with a cold water inlet pipeline and a hot water outlet pipeline respectively, the cold water inlet pipeline is used for feeding cold water, and the hot water outlet pipeline is used for outputting hot water obtained after heat exchange. According to the utility model, the loss in electric power and heat energy production and transportation processes is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to fuel cell technical field, concretely relates to a fuel cell combined heat and power system. BACKGROUND

[0002] Fuel cells, as a kind of efficient, clean energy conversion device, have been widely concerned in recent years in electric vehicles, ships, unmanned aerial vehicles and other various traffic carriers and fixed power generation applications. Its basic principle is to convert the chemical energy of fuel into electrical energy through electrochemical reaction. However, the current market most fuel cell power generation devices mainly focus on the use of electrical energy, and lack effective treatment and utilization strategy for the heat energy generated, which limits the overall energy utilization rate of fuel cell system to some extent.

[0003] For example, the patent application with publication number CN11 6960399A discloses a megawatt hydrogen fuel cell distributed power generation system. This patent mainly describes the electrical energy utilization scheme of fuel cell engine in the power generation process, but does not involve the recovery of fuel cell engine cooling water heat and the treatment of tail water. In actual operation, when the fuel cell is running, hydrogen gas is input to the anode, hydrogen molecules are dissociated into hydrogen ions and electrons under the action of the positive electrode catalyst, and the electrons flow to the negative electrode through the external circuit. At the same time, oxygen is input to the negative electrode, and oxygen combines with electrons and hydrogen ions to generate water under the action of the catalyst and releases heat. This electrochemical reaction not only produces electrical energy, but also produces a large amount of heat energy, especially in the cooling liquid and tail water of the fuel cell, which contains a large amount of heat energy.

[0004] Cooling water is a key part of fuel cell system for maintaining the temperature stability of the stack. It maintains the fuel cell in an appropriate working temperature range by absorbing the heat generated by the stack. However, the traditional fuel cell power generation device usually only simply circulates the cooling water back to the system for heat dissipation, without effectively utilizing the heat energy contained therein. This waste of heat energy not only reduces the overall energy efficiency of the system, but also increases the burden and complexity of the cooling system.

[0005] On the other hand, the tail water of fuel cell is also an important source of heat energy. In the operation process of fuel cell, a large amount of water will be discharged in the form of tail water because the product of electrochemical reaction is water. This part of water not only contains the heat generated by fuel cell reaction, but also may contain unreacted hydrogen or other valuable substances. At present, the treatment of tail water by most fuel cell systems is limited to simple discharge, without further recovery and utilization, which also leads to waste of resources.

[0006] In view of the above problems, the industry has begun to explore how to effectively recover and utilize the heat energy generated by fuel cells. For example, Shanghai Electric Group Co., Ltd. has obtained a patent named "a fuel cell cogeneration system" (authorized announcement number CN220253283U), which proposes an innovative solution. The system adds a heat storage system to the traditional fuel cell system, and through the heat exchanger, the cooling liquid heat at the outlet is exchanged to the heat storage system for heat storage, and then heat is supplied to external equipment, greatly improving the comprehensive utilization rate of fuel cell energy.

[0007] In addition, for the treatment of tail water, some researchers have proposed a tail gas recovery device and its drainage method, which can accurately control the opening and closing time of the drainage valve, realize the recovery of heat in the tail water and the reuse of unreacted fuel, and further improve the overall energy efficiency of the fuel cell system.

[0008] In summary, the existing fuel cell power generation device has made significant progress in electric energy utilization, but there is still a lot of room for improvement in heat energy recovery and utilization. Through innovative technical means such as cogeneration systems, tail gas recovery devices, etc., the heat energy generated by fuel cells can be effectively recovered and utilized, improving the overall energy efficiency of the system and promoting the further development and application of fuel cell technology. In the future, with the continuous progress of technology and the gradual reduction of costs, the application prospect of fuel cell power generation devices in the energy field will be more extensive. Practical new type content

[0009] Based on the deficiencies in the prior art, the purpose of the present application is to provide a fuel cell cogeneration system that utilizes the simultaneous generation of electricity and heat by fuel cell engines to provide heat and electricity. The efficiency of the present application is the sum of the thermal efficiency of the fuel cell engine and the electrical efficiency of the fuel cell engine. As a distributed energy supply device, the present application reduces the loss of electricity and heat production and transportation.

[0010] To achieve the above purpose, the present application provides a fuel cell cogeneration system, which comprises a fuel cell engine, the fuel cell engine comprising an electric pile, the electric pile having an electric power output circuit (power device) and a cooling pipeline, the cooling pipeline having a cooling water inlet and a cooling water outlet, the electric power output circuit being provided with a DC / DC converter and a shunt in sequence, the shunt dividing the circuit into two paths, one path being a low-voltage circuit and the other path being a high-voltage circuit, the low-voltage circuit being used to supply power to the electrical components in the fuel cell engine after being stepped down, and the high-voltage circuit being used to connect to the power grid or supply power to local loads.

[0011] The cooling water inlet is connected with the first interface of the first three-way valve, the cooling water outlet is connected with the first interface of the second three-way valve, the second interface of the first three-way valve is connected with the second interface of the second three-way valve, and the third interface of the first three-way valve and the third interface of the second three-way valve are connected with the inlet and outlet of one side of the plate heat exchanger; the inlet and outlet of the other side of the plate heat exchanger are connected with the cold water inlet pipeline and the hot water outlet pipeline (heat exchange device) respectively, the cold water inlet pipeline is used for feeding cold water, and the hot water outlet pipeline is used for outputting hot water obtained after heat exchange.

[0012] Preferably, the low-voltage circuit is sequentially provided with a voltage reduction DC / DC converter and a battery, the voltage reduction DC / DC converter is used for voltage reduction, and the battery is used for storing electric energy and supplying power to the electric components in the fuel cell engine.

[0013] Further, the high-voltage circuit is sequentially provided with a busbar cabinet, a controller, a DC / AC converter and a transformer, and the high-voltage circuit is used for connecting a power grid or supplying power to local loads.

[0014] Further, one end of the cold water inlet pipeline away from the plate heat exchanger is used as a cold water supplementing end, and the cold water inlet pipeline is sequentially provided with a cold water stop valve, a Y-shaped filter, a cold water storage tank and a water pump from the cold water supplementing end to the end connected with the plate heat exchanger.

[0015] Further, one end of the cold water inlet pipeline away from the plate heat exchanger is used as a cold water supplementing end, and the cold water inlet pipeline is sequentially provided with a cold water stop valve, a Y-shaped filter, a cold water storage tank and a water pump from the cold water supplementing end to the end connected with the plate heat exchanger.

[0016] Further, the hydrogen inlet pipeline (hydrogen inlet device) for feeding hydrogen into the electric pile is further included, and the hydrogen inlet pipeline is sequentially provided with a hydrogen storage tank, a first filter and a flow meter from an upstream end to a downstream end, and one stop valve is arranged on each side of the first filter and each side of the flow meter.

[0017] As a preferred scheme of the utility model, a first fire stopping device is arranged between the first filter and the flow meter on the hydrogen inlet pipeline, and one stop valve is arranged on the side of the first fire stopping device close to the hydrogen inlet pipeline;

[0018] A second fire stopping device is further arranged downstream of the flow meter on the hydrogen inlet pipeline, and one stop valve is arranged on the side of the second fire stopping device close to the hydrogen inlet pipeline.

[0019] The fuel cell combined heat and power system further includes a nitrogen purging branch, one end of the nitrogen purging branch is connected with a section of the hydrogen inlet pipeline between the first filter and the first fire stopping device.

[0020] The nitrogen gas purging branch is sequentially provided with a nitrogen gas storage tank and a second filter from an upstream end to a downstream end, and a stop valve is arranged on each side of the second filter.

[0021] Preferably, the hydrogen gas inlet pipeline is connected with a bypass branch on both sides of the flow meter, and the bypass branch is provided with a bypass stop valve.

[0022] The bypass stop valve plays a protection role, and fuel can still be supplied to the fuel cell engine to make it stable stop when the flow meter fails.

[0023] The fuel cell heat and power cogeneration system has the following beneficial effects:

[0024] 1. Highly modular integration, which can expand the power supply capacity by parallel connection of devices;

[0025] 2. Can be used as a distributed functional device to reduce energy loss by arranging the use scene periphery;

[0026] 3. The terminal can flexibly select whether to use the heat energy of the fuel cell engine, thereby avoiding waste of water resources. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the fuel cell heat and power cogeneration system.

[0028] Figure 2 It is an internal schematic diagram of the hydrogen gas inlet device.

[0029] Figure 3 It is an internal schematic diagram of the power device.

[0030] Figure 4 It is an internal schematic diagram of the heat exchange device.

[0031] Marked in the figure: 01a-first three-way valve, 02a-radiator, 03a-second three-way valve, 04a-plate heat exchanger, 01b-cold water stop valve, 02b-Y filter, 03b-cold water storage tank, 04b-water pump, 05b-hot water storage tank, 06b-hot water stop valve, 01c-cooling water inlet, 02c-cooling water outlet, 01d-cold water water supply end, 02d-hot water water supply end, 11-DC / DC converter, 12-shunt, 121-voltage reducing DC / DC converter, 122-battery, 123-converging cabinet, 124-controller, 125-DC / AC converter, 126-transformer, 01-hydrogen gas storage tank, 02-first filter, 03-flow meter, 04-first flame arrestor, 05-second flame arrestor, 06-nitrogen gas storage tank, 07-second filter, 08-bypass stop valve, 09-pressure sensor, 10-temperature sensor. DETAILED DESCRIPTION

[0032] As shown in Figures 1-4 The utility model provides a kind of fuel cell cogeneration system, including fuel cell engine, fuel cell engine includes electric pile, electric pile has power generation electric energy output circuit and cooling pipeline, cooling pipeline has cooling water import 01c and cooling water export 02c, power generation electric energy output circuit is sequentially provided with: DC / DC converter 11 and shunt 12, shunt 12 is divided into two ways by circuit, one way is low-voltage circuit, another way is high-voltage circuit, low-voltage circuit is used to power supply to electric component in fuel cell engine after voltage reduction, high-voltage circuit is used to connect power grid or power supply to local load, by DC / DC converter and shunt, the electric energy generated by fuel cell engine is flexibly divided into low-voltage and high-voltage two ways;Low-voltage circuit is used to power supply to electric component in fuel cell engine, and high-voltage circuit can be used to connect power grid or power supply to local load, and this design meets different power demand, and improves the utilization rate of electric energy;

[0033] Cooling water import 01c connects the first interface of first three-way valve 01a, cooling water export 02c connects the first interface of second three-way valve 03a, and the second interface of first three-way valve 01a is connected with the second interface of second three-way valve 03a, and the third interface of first three-way valve 01a and the third interface of second three-way valve 03a are connected into the import and export of one side of plate heat exchanger 04a;The import and export of other side of plate heat exchanger 04a are connected with cold water inlet pipeline and hot water outlet pipeline respectively, and cold water inlet pipeline is used to import cold water, and hot water outlet pipeline is used to output hot water obtained after heat exchange.

[0034] By using the heat energy in cooling pipeline, the heat of cooling water is transferred to cold water through plate heat exchanger, so as to output hot water, and this cogeneration mode greatly improves the comprehensive utilization efficiency of energy, and realizes diversified utilization of energy.

[0035] In the Figure 3 embodiment of the utility model, low-voltage circuit is sequentially provided with voltage reduction DC / DC converter (DCL) 121 and battery 122, voltage reduction DC / DC converter 121 is used to reduce voltage, and battery 122 is used to store electric energy and power supply to electric component (such as sensor etc.) in fuel cell engine.

[0036] High-voltage circuit is sequentially provided with busbar cabinet 123, controller 124, DC / AC converter 125 and transformer 126, and high-voltage circuit is used to connect power grid or power supply to local load.

[0037] The cold water inlet pipeline is away from one end of the plate heat exchanger 04a as a cold water supplement end 01d, and the cold water inlet pipeline is sequentially provided with a cold water stop valve 01b, a Y-shaped filter 02b, a cold water storage tank 03b and a water pump 04b from the cold water supplement end 01d to one end of the plate heat exchanger 04a.

[0038] The hot water outlet pipeline is away from one end of the plate heat exchanger 04a as a hot water supply end 02d, and the hot water outlet pipeline is sequentially provided with a hot water storage tank 05b and a hot water stop valve 06b from one end of the plate heat exchanger 04a to the hot water supply end 02d.

[0039] The fuel cell heat and power cogeneration system further comprises a hydrogen inlet pipeline for feeding hydrogen into the hydrogen storage tank 01, the first filter 02 and the flow meter 03.

[0040] The various valves and filters on the cold water inlet pipeline and the hot water outlet pipeline can facilitate cleaning and maintenance of the system.

[0041] The hydrogen inlet pipeline is provided with a first fire barrier device 04 between the first filter 02 and the flow meter 03, and one stop valve is arranged on the side of the first fire barrier device 04 close to the hydrogen inlet pipeline.

[0042] The hydrogen inlet pipeline is further provided with a second fire barrier device 05 downstream of the flow meter 03, and one stop valve is arranged on the side of the second fire barrier device 05 close to the hydrogen inlet pipeline.

[0043] The fuel cell heat and power cogeneration system further comprises a nitrogen purge branch, and one end of the nitrogen purge branch is connected to a section of the hydrogen inlet pipeline between the first filter 02 and the first fire barrier device 04.

[0044] The nitrogen purge branch is sequentially provided with a nitrogen storage tank 06 and a second filter 07 from an upstream end to a downstream end, and one stop valve is arranged on each side of the second filter 07.

[0045] The hydrogen inlet pipeline is provided with multiple stop valves, fire barrier devices and a nitrogen purge branch, which can effectively prevent hydrogen leakage and fire hazards and improve the safety of the system.

[0046] As shown in Figure 2 A pressure sensor 09 is further arranged upstream of the first fire barrier device and the second fire barrier device and downstream of the second filter on the hydrogen inlet pipeline, so as to facilitate real-time monitoring of the pressure of the hydrogen inlet pipeline.

[0047] The hydrogen inlet pipeline is connected with bypass branches on both sides of the flow meter 03, and the bypass branches are provided with bypass stop valves 08.

[0048] The bypass branches connected with the hydrogen inlet pipeline on both sides of the flow meter and the bypass stop valves arranged on the bypass branches enable the system to continue to supply fuel to the fuel cell engine when the flow meter fails, thereby ensuring stable operation of the system and smoothness of the shutdown process.

[0049] In use, hydrogen passes through the hydrogen inlet pipeline and reaches the anode air inlet of the fuel cell engine; air passes through the air filter and reaches the cathode air inlet of the fuel cell engine; the cooling water of the fuel cell engine exchanges heat with external cooling water through the plate heat exchanger 04a, thereby providing hot water to the outside, i.e. water flows from the cooling water outlet 02c of the fuel cell engine, through the first three-way valve 01a, the plate heat exchanger 04a and the second three-way valve 03a, and back to the cooling water inlet 01c of the fuel cell engine, while the water of the cooling water supply end 01d flows through the cooling water stop valve 01b, the Y-type filter 02b, the cooling water storage tank 03b, the water pump 04b, the plate heat exchanger 04a, the hot water storage tank 05b and the hot water stop valve 06b and finally is supplied to the hot water supply end 02d, which constitutes a water circulation for the fuel cell engine to supply heat to the outside; or the fuel cell engine can directly exchange heat with the outside environment through a radiator. The electricity generated by the fuel cell engine respectively reaches the shunt 12 after passing through the DC / DC converter 11, one way reaches the step-down DC / DC converter 121, is stepped down to 24V low-voltage electricity and is stored in the battery 122 for use by sensors and other components of the fuel cell engine; the other way passes through the busbar cabinet 123, the controller 124, the DC / AC converter 125 and the transformer 126, and is converted into electricity that can be supplied to the power grid or used by local loads. The utility model reduces the loss in the production and transportation process of electricity and heat.

Claims

1. A fuel cell cogeneration system comprising a fuel cell engine including an electrical stack having an electrical power output line and a cooling circuit having a cooling water inlet and a cooling water outlet, characterized by, The power generation electric energy output circuit is sequentially provided with a DC / DC converter and a shunt, the shunt divides the circuit into two paths, one path is a low-voltage circuit, and the other path is a high-voltage circuit, the low-voltage circuit is used for supplying power to the electric components in the fuel cell engine after being stepped down, and the high-voltage circuit is used for connecting to a power grid or supplying power to a local load. The cooling water inlet is connected to a first interface of a first three-way valve, the cooling water outlet is connected to a first interface of a second three-way valve, a radiator is connected between a second interface of the first three-way valve and a second interface of the second three-way valve, and a third interface of the first three-way valve and a third interface of the second three-way valve are connected to an inlet and an outlet of one side of a plate heat exchanger; an inlet and an outlet of the other side of the plate heat exchanger are respectively connected to a cold water inlet pipeline and a hot water outlet pipeline, the cold water inlet pipeline is used for feeding cold water, and the hot water outlet pipeline is used for outputting hot water obtained after heat exchange.

2. The fuel cell cogeneration system of claim 1, wherein The low-voltage circuit is sequentially provided with a step-down DC / DC converter and a battery, the step-down DC / DC converter is used for stepping down voltage, and the battery is used for storing electric energy and supplying power to the electric components in the fuel cell engine.

3. The fuel cell cogeneration system of claim 1, wherein The high-voltage circuit is sequentially provided with a bus cabinet, a controller, a DC / AC converter and a transformer, and the high-voltage circuit is used for connecting to a power grid or supplying power to a local load.

4. The fuel cell cogeneration system of claim 1, wherein, An end of the cold water inlet pipeline away from the plate heat exchanger serves as a cold water feeding end, and the cold water inlet pipeline is sequentially provided with a cold water stop valve, a Y-shaped filter, a cold water storage tank and a water pump from the cold water feeding end to an end connected to the plate heat exchanger.

5. The fuel cell cogeneration system of claim 1 wherein, An end of the hot water outlet pipeline away from the plate heat exchanger serves as a hot water supply end, and the hot water outlet pipeline is sequentially provided with a hot water storage tank and a hot water stop valve from an end connected to the plate heat exchanger to the hot water supply end.

6. The fuel cell cogeneration system of claim 1 wherein, A hydrogen inlet pipeline for feeding hydrogen to the electric pile is further included, and the hydrogen inlet pipeline is sequentially provided with a hydrogen storage tank and a first filter from an upstream end to a downstream end, and two sides of the first filter and two sides of a flowmeter are respectively provided with a stop valve.

7. The fuel cell cogeneration system of claim 6 wherein, A first fire blocking device is arranged between the first filter and the flowmeter on the hydrogen inlet pipeline, and a stop valve is arranged on a side of the first fire blocking device close to the hydrogen inlet pipeline. A second fire blocking device is further arranged downstream of the flowmeter on the hydrogen inlet pipeline, and a stop valve is arranged on a side of the second fire blocking device close to the hydrogen inlet pipeline.

8. The fuel cell cogeneration system of claim 7 wherein, A nitrogen purging branch is further included, and one end of the nitrogen purging branch is connected to a section of the hydrogen inlet pipeline between the first filter and the first fire blocking device. The nitrogen purging branch is sequentially provided with a nitrogen storage tank and a second filter from an upstream end to a downstream end, and two sides of the second filter are respectively provided with a stop valve.

9. The fuel cell cogeneration system of claim 6 wherein, The hydrogen inlet pipeline is connected with bypass branches on two sides of the flowmeter, and the bypass branches are provided with bypass stop valves.

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