CN115000452B - Fuel cell-based combined heat and power system and operation method - Google Patents

Abstract

The invention relates to a combined cooling heating power system based on a fuel cell and an operation method, wherein the system comprises a fuel cell system, an ORC system, a waste heat exchanger, an absorption refrigeration system and a control system; the fuel cell system is used for generating power, the cooling liquid of the fuel cell system is used for providing heat sources for the ORC system, the waste heat exchanger and the absorption refrigeration system respectively, the ORC system can provide additional electric energy and a first part of heat energy, the waste heat exchanger can provide a second part of heat energy, the absorption refrigeration system can provide cold energy, and the cooling liquid after heat release flows back to the cooling system of the fuel cell system to form circulation; the control system is used for distributing the cooling liquid supplied to the ORC system, the waste heat exchanger and the absorption refrigeration system according to the operation load of the fuel cell system and the user demand, and controlling the heat supply mode to supply heat in a coordinated manner through the first part of heat energy and the second part of heat energy or supply heat independently through the second part of heat energy. The invention improves the energy utilization efficiency of the system.

Description

Fuel cell-based combined heat and power system and operation method

Technical Field

The present invention relates to the technical field of fuel cell waste heat utilization, in particular to a fuel cell-based combined heat, cooling and power system and an operation method.

Background technique

Hydrogen fuel cells generate electricity through chemical reactions, with small installation scale, less waste emissions, and higher power generation efficiency than traditional generator sets. Commonly used fuel cell types, such as proton exchange membrane fuel cells and solid oxide fuel cells, can generate electricity with an efficiency of up to 40-60%, and their overall efficiency of combined heat and power generation is above 85%.

In the existing technology, the waste heat utilization method and operation mode of the fuel cell cooling and heating power system are relatively simple and cannot meet the diverse needs of the user side. Therefore, it is necessary to optimize the waste heat utilization method from the perspective of system structure optimization to further improve the system energy utilization efficiency.

Summary of the invention

In view of the deficiencies in the prior art, the present invention provides a combined heating, cooling and power system based on a fuel cell and an operation method thereof, the purpose of which is to improve the energy utilization efficiency of the system.

The technical solution adopted by the present invention is as follows:

The present invention provides a combined cooling, heating and power system based on a fuel cell, comprising a fuel cell system, an ORC system, a waste heat exchanger, an absorption refrigeration system and a control system;

The fuel cell system is used to generate electricity, and the coolant of the cooling system of the fuel cell system provides heat sources for the ORC system, the waste heat exchanger and the absorption refrigeration system respectively. The ORC system is driven by the heat source to provide additional electrical energy and a first part of heat energy, the waste heat exchanger can provide a second part of heat energy, and the absorption refrigeration system is driven by the heat source to provide cold energy. The coolant after releasing heat flows back to the cooling system of the fuel cell system to form a cycle;

The control system is used to distribute the coolant supplied to the ORC system, the waste heat exchanger and the absorption refrigeration system according to the operating load of the fuel cell system and user needs, and control the heating mode to provide heating through the first part of heat energy and the second part of heat energy in coordination, or to provide heating through the second part of heat energy alone.

Further technical solutions are:

The heating pipeline includes a heating return pipe and a heating outlet pipe respectively connected to the user side;

The heating return pipe is connected to the water side inlet of the ORC system condenser, the water side outlet of the ORC system condenser is connected to the cold medium side inlet of the waste heat exchanger, and the cold medium side outlet of the waste heat exchanger is connected to the heating water outlet pipe to form a heating loop.

A heating peak-shaving device is also connected in series on the heating water outlet pipe.

The cooling pipeline includes a cooling return pipe and a cooling outlet pipe respectively connected to the user side;

The cooling water return pipe is connected to the water side inlet of the refrigeration system evaporator of the absorption refrigeration system, and the water side outlet of the refrigeration system evaporator is connected to the cooling water outlet pipe to form a cooling circuit.

A cooling peak-shaving device is also connected in series on the cooling water outlet pipe.

The cooling system of the fuel cell system includes a supply pipe and a return pipe for the coolant;

The outlet of the liquid supply pipe is respectively connected to the heat source inlet of the ORC system evaporator, the heat medium side inlet of the waste heat exchanger, and the heat source inlet of the generator of the absorption refrigeration system of the ORC system, and control valves are respectively provided on the connecting pipelines. The heat source outlet of the ORC system evaporator, the heat medium side outlet of the waste heat exchanger, and the heat source outlet of the generator are respectively connected to the inlet of the return pipe to form a coolant loop.

The battery output circuit of the fuel cell system is connected to the power supply circuit through an inverter. The power supply circuit is used to connect to the user side and is provided with a voltage regulating device.

The ORC output circuit of the ORC system is connected to the power supply circuit.

The present invention also provides an operation method of the fuel cell-based combined heat and power system, comprising:

The fuel cell system operates to provide electricity to users;

When the user issues a heating request, the control system determines the operating load of the fuel cell system, and under the premise that the operating load of the fuel cell system is met, according to the heating request temperature, the coolant supply of the waste heat exchanger is turned on, and the coolant supply of the ORC system and the absorption refrigeration system is cut off, and the heating mode is switched to heat the user alone through the second part of the heat energy provided by the waste heat exchanger, or the coolant supply of the waste heat exchanger and the ORC system is turned on, and the coolant supply of the absorption refrigeration system is cut off, and the heating mode is switched to heat the user through the first part of the heat energy and the second part of the heat energy in coordination;

When the user issues a cooling request, the control system determines the operating load of the fuel cell system, and on the premise that the operating load of the fuel cell system is met, the coolant supply of the absorption refrigeration system is turned on, and the coolant supply of the ORC system and the waste heat exchanger is cut off at the same time, to provide cooling for the user; on this basis, the user issues a heating request again, and on the premise that the operating load of the fuel cell system is met, the coolant supply of the waste heat exchanger is turned on according to the heating request temperature, and the heating mode is to provide heating to the user alone through the second part of heat energy, or to turn on the coolant supply of the waste heat exchanger and the ORC system, and the heating mode is to provide heating to the user through the first part of heat energy and the second part of heat energy in coordination;

When the user sends a request for cooling and heating at the same time, the control system determines the operating load of the fuel cell system. On the premise that the operating load of the fuel cell system is met, the coolant supply to the ORC system, waste heat exchanger and absorption refrigeration system is started at the same time to achieve combined cooling, heating and power.

The beneficial effects of the present invention are as follows:

In addition to being used for direct heating or hot water supply, the fuel cell waste heat of the present invention can be combined with an organic Rankine cycle (ORC) or an absorption refrigeration system to form a composite fuel cell combined heat and power system to obtain additional electrical energy or cooling capacity, thereby achieving the flexible operation of using waste heat to provide additional power generation, cooling, and heating effects, and improving the flexibility and efficiency of fuel cell system applications.

The present invention also optimizes the waste heat utilization method. The return water of the heating system can first enter the ORC system condenser for primary heating, and then enter the waste heat exchanger for secondary heating, thereby realizing the cascade utilization of the waste heat of the fuel cell and further improving the energy efficiency of the system.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the system structure of the present invention.

FIG. 2 is a schematic diagram of the structure of a fuel cell system of the present invention.

FIG. 3 is a schematic diagram of the ORC system structure of the present invention.

FIG. 4 is a schematic structural diagram of an absorption refrigeration system of the present invention.

In the figure: 1. fuel cell system; 2. ORC system; 3. waste heat exchanger; 4. absorption refrigeration system; 5. valve five; 6. valve six; 7. valve seven; 8. inverter; 9. voltage regulator; 10. heating peak-shaving device; 11. cooling peak-shaving device;

101, fuel cell; 102, circulation pump; 201, ORC system evaporator; 202, expander; 203, generator; 204, ORC system condenser; 205, working fluid pump;

401, generator; 402, refrigeration system condenser; 403, refrigerant throttle valve; 404, refrigeration system evaporator; 405, absorber; 406, solution pump; 407, solution throttle valve;

1001. Air inlet pipe; 1002. Air outlet pipe; 1003. Hydrogen inlet pipe; 1004. Hydrogen outlet pipe; 1005. Drain pipe; 1006. Liquid supply pipe; 1007. Liquid return pipe; 1008. Battery output circuit; 1009. ORC output circuit; 1010. Power supply circuit; 1011. Heating return pipe; 1012. Heating outlet pipe; 1013. Cooling return pipe; 1014. Cooling outlet pipe.

Detailed ways

The specific implementation of the present invention is described below with reference to the accompanying drawings.

As shown in FIG1 , the fuel cell-based combined cooling, heating and power system of this embodiment includes a fuel cell system 1, an ORC system 2, a waste heat exchanger 3, an absorption refrigeration system 4 and a control system;

The fuel cell system 1 is used for power generation. The coolant of the cooling system of the fuel cell system 1 provides heat sources for the ORC system 2, the waste heat exchanger 3 and the absorption refrigeration system 4 respectively. The ORC system 2 is driven by the heat source to provide additional electrical energy and a first part of heat energy. The waste heat exchanger 3 can provide a second part of heat energy. The absorption refrigeration system 4 is driven by the heat source to provide cold energy. The coolant after releasing heat flows back to the cooling system of the fuel cell system 1 to form a cycle.

The control system is used to distribute the coolant supplied to the ORC system 2, the waste heat exchanger 3 and the absorption refrigeration system 4 according to the operating load of the fuel cell system 1 and user needs, and control the heating mode to provide heating through the first part of the heat energy and the second part of the heat energy, or to provide heating through the second part of the heat energy alone.

The heating pipeline includes a heating return pipe 1011 and a heating outlet pipe 1012 respectively connected to the user side;

As shown in Figures 1 and 2, the heating return water pipe 1011 is connected to the water side inlet of the ORC system condenser 204, the water side outlet of the ORC system condenser 204 is connected to the cold medium side inlet of the waste heat exchanger 3, and the cold medium side outlet of the waste heat exchanger 3 is connected to the heating water outlet pipe 1012 to form a heating loop.

Specifically, a heating peak-shaving device 10 is also connected in series to the heating water outlet pipe 1012 .

The hot water return water on the user side enters the ORC system condenser 204 through the heating return pipe 1011 to absorb its condensation heat, achieving the first stage of temperature rise, and then enters the waste heat exchanger 3 to exchange heat with the coolant to achieve the second stage of temperature rise, and then is transported to the user side through the heating outlet pipe 1012.

The heat peak-shaving device 10 is specifically a boiler or an electric heat pump unit, which can meet the user's heating demand when the load of the fuel cell system 1 is low.

Among them, as shown in Figure 1, the cooling pipeline includes a cooling return pipe 1013 and a cooling outlet pipe 1014 respectively connected to the user side; the cooling return pipe 1013 is connected to the water side inlet of the refrigeration system evaporator 404 of the absorption refrigeration system 4, and the water side outlet of the refrigeration system evaporator 404 is connected to the cooling outlet pipe 1014 to form a cooling circuit.

Specifically, a cooling peak-shaving device 11 is also connected in series to the cooling water outlet pipe 1014 .

The cold water return from the user side enters the refrigeration system evaporator 404 through the cooling water return pipe 1013 to be cooled, and then is transported to the user side through the cooling water outlet pipe 1014.

The cooling peak-shaving device 11 is specifically an electric refrigeration unit, which can meet the cooling demand of the user when the load of the fuel cell system 1 is low.

As shown in FIG. 1 , the cooling system of the fuel cell system 1 includes a supply pipe 1006 and a return pipe 1007 for the coolant; the outlet of the supply pipe 1006 is respectively connected to the heat source inlet of the ORC system evaporator 201 of the ORC system 2, the heat medium side inlet of the waste heat exchanger 3, and the heat source inlet of the generator 401 of the absorption refrigeration system 4, and control valves are respectively provided on the connecting pipelines, and the heat source outlet of the ORC system evaporator 201, the heat medium side outlet of the waste heat exchanger 3, and the heat source outlet of the generator 401 are respectively connected to the inlet of the return pipe 1007 to form a coolant loop.

Specifically, a circulation pump 102 is provided on the liquid supply pipe 1006 .

The battery output circuit 1008 of the fuel cell system 1 is connected to the power supply circuit 1010 through the inverter 8. The power supply circuit 1010 is used to connect to the user side. The power supply circuit 1010 is provided with a voltage regulating device 9.

The ORC output circuit 1009 of the ORC system 2 is connected to the power supply circuit 1010 .

Specifically, the fuel cell system 1, ORC system 2 and absorption refrigeration system 4 used in this embodiment are all conventional systems. The ORC system is an organic Rankine cycle system, the ORC system 2 is a single-stage or multi-stage system, and the absorption refrigeration system 4 is a single-stage or multi-stage, single-effect or multi-effect absorption refrigeration system.

As shown in FIG2 , the fuel cell system 1 includes a fuel cell 101, an air inlet pipe 1001, an air outlet pipe 1002, a hydrogen inlet pipe 1003, a hydrogen outlet pipe 1004, and a drain pipe 1005. The working process is as follows:

Air enters the fuel cell through the air inlet pipe 1001, and hydrogen enters the fuel cell through the hydrogen inlet pipe 1003. The air and oxygen entering the fuel cell undergo an electrochemical reaction according to the reaction formula _2H2 + _O2 → _2H2O +electricity+heat. The oxygen in the reaction formula is the oxygen contained in the air, and the temperature of the electrochemical reaction process is about 150°C (taking the reaction temperature of a high-temperature proton exchange membrane fuel cell as an example). The air that does not participate in the reaction is discharged from the air outlet pipe 1002, the hydrogen that does not participate in the reaction is discharged from the hydrogen outlet pipe 1004, the water generated by the reaction is discharged from the drain pipe 1005, the heat generated by the reaction is cooled by the fuel cell cooling system, and the electricity generated by the reaction is output by the battery output circuit 1008 to achieve a power generation effect.

As shown in FIG3 , the ORC system 2 includes an ORC system evaporator 201, an expander 202, a generator 203, an ORC system condenser 204, and a working fluid pump 205. The working process is:

In the ORC system evaporator 201, the coolant from the liquid supply pipe 1006 is used as a driving heat source to heat the high-pressure liquid working medium of the ORC system evaporator 201. The high-pressure liquid working medium absorbs heat and evaporates, becoming a high-pressure gaseous working medium and entering the expander 202. In the expander 202, the high-pressure gaseous working medium expands and does work, and transmits the mechanical work to the generator 203. The generator 203 converts the mechanical energy of the expander 202 into electrical energy, and the generated electrical energy is output by the ORC output circuit 1009 to achieve the purpose of power generation. After the high-pressure gaseous working medium works, the pressure is reduced and becomes a low-pressure gaseous working medium, which enters the ORC system condenser 204.

The function of the ORC system condenser 204 is to condense the low-pressure gaseous working medium into a liquid working medium so that it can be pressurized by the working medium pump 205 and then returned to the ORC system evaporator 201. The gaseous working medium releases a large amount of latent heat to the water in the heating return pipe 1011 during the condensation process, so the water temperature in the heating return pipe 1011 cannot be too high, otherwise it will inhibit the condensation process of the gaseous working medium, thereby reducing the power generation efficiency of the ORC system. Therefore, the outlet water temperature of the ORC system condenser 204 needs to be controlled.

Referring to FIG. 1 , in the waste heat exchanger 3 , the coolant from the fuel cell 101 is used as a heat source to further heat the hot water from the ORC system condenser 204 , and the water temperature of the heating return pipe 1011 is adjusted according to actual needs to achieve water supply temperature regulation.

Referring to FIG4 , the absorption refrigeration system 4 comprises a generator 401, a refrigeration system condenser 402, a refrigerant throttle valve 403, a refrigeration system evaporator 404, an absorber 405, a solution pump 406, and a solution throttle valve 407. The working process is:

In the generator 401, the coolant from the liquid supply pipe 1006 is used as a driving heat source to heat the dilute solution in the generator 401, causing the refrigerant components in the solution to evaporate and form a high-temperature gaseous refrigerant. The concentration of the dilute solution increases and becomes a concentrated solution, which enters the absorber 405 after throttling and reducing the pressure by the solution throttle valve 407, and the evaporated high-temperature gaseous refrigerant enters the refrigeration system condenser 402. In the refrigeration system condenser 402, the high-temperature gaseous refrigerant releases latent heat to the cooling water of the refrigeration system condenser 402, and the high-temperature gaseous refrigerant becomes a liquid refrigerant, which enters the absorption refrigeration system evaporator 404 after throttling and reducing the pressure by the refrigerant throttle valve 403. The cooling water of the refrigeration system condenser 402 absorbs the latent heat, and the temperature rises, and the heat is released to the outside of the system through the external heat dissipation device.

In the evaporator 404 of the refrigeration system, due to the negative pressure inside, the liquid refrigerant reaches saturation and evaporates at about 5°C. During the evaporation process, the liquid refrigerant absorbs the heat of the water in the cooling return pipe 1013, becomes a gaseous refrigerant, and then enters the absorber 405. The water in the cooling return pipe 1013 releases heat, the temperature drops, and returns to the cooling terminal device through the cooling outlet pipe 1014 to achieve the purpose of cooling.

In the absorber 405, the concentrated solution from the generator 401 absorbs the gaseous refrigerant from the evaporator 404 of the refrigeration system, and the concentration is reduced. At the same time, the concentrated solution releases heat to the cooling water of the absorber 405, and then is pressurized by the solution pump 406 and returned to the generator 401. After the cooling water of the absorber 405 absorbs the heat, it releases the heat to the outside of the system through the external heat dissipation device.

The operating method of the fuel cell combined heat and power system of this embodiment includes:

The fuel cell system 1 operates to provide power to the user;

When the user issues a heating request, the control system determines the operating load of the fuel cell system 1, and on the premise that the operating load of the fuel cell system 1 is met, the coolant supply of the waste heat exchanger 3 is turned on, and the coolant supply of the ORC system 2 and the absorption refrigeration system 4 is cut off, and the heating mode is switched to heat the user alone through the second part of the heat energy provided by the waste heat exchanger 3, or the coolant supply of the waste heat exchanger 3 and the ORC system 2 is turned on, and the coolant supply of the absorption refrigeration system 4 is cut off, and the heating mode is switched to heat the user through the first part of the heat energy and the second part of the heat energy in coordination;

Specifically, when the fuel cell system 1 is running at a low load, the coolant supply of the waste heat exchanger 3 is turned on, and the coolant supply of the ORC system 2 and the absorption refrigeration system 4 is cut off at the same time, and the heating mode is switched to heat the user separately through the second part of the heat energy provided by the waste heat exchanger 3;

Specifically, when the fuel cell system 1 is running at high load, the coolant supply to the waste heat exchanger 3 and the ORC system 2 is turned on, and the coolant supply to the absorption refrigeration system 4 is cut off, and the heating mode is switched to heat the user by synergistically using the first part of the heat energy and the second part of the heat energy;

When the user issues a cooling request, the control system determines the operating load of the fuel cell system 1, and on the premise that the operating load of the fuel cell system 1 is met, starts the coolant supply of the absorption refrigeration system 4, and cuts off the coolant supply of the ORC system 2 and the waste heat exchanger 3, so as to provide cooling for the user; on this basis, the user issues a heating request again, and on the premise that the operating load of the fuel cell system 1 is met, starts the coolant supply of the waste heat exchanger 3, and the heating mode is to heat the user alone through the second part of the heat energy, or starts the coolant supply of the waste heat exchanger 3 and the ORC system 2, and the heating mode is to heat the user through the first part of the heat energy and the second part of the heat energy;

When the user sends a request for cooling and heating at the same time, the control system determines the operating load of the fuel cell system 1, and on the premise that the operating load of the fuel cell system 1 is met, simultaneously starts the coolant supply of the ORC system 2, the waste heat exchanger 3 and the absorption refrigeration system 4 to realize combined cooling, heating and power.

Specifically, according to actual needs, the flow direction of the coolant can be selected by turning on and off valve five 5, valve six 6, and valve seven 7 to achieve flexible use of the waste heat of the fuel cell. Specific examples are as follows:

The valve six 6 is opened, the valve five 5 and the valve seven 7 are closed, and the coolant enters the waste heat exchanger 3. The coolant can achieve a heating effect through the waste heat exchanger 3. Combined with the power generation effect of the fuel cell 101, a first cogeneration operation state is provided.

The valve five 5 and the valve six 6 are opened, the valve seven 7 is closed, and the coolant enters the ORC system 2 and the waste heat exchanger 3. Through the ORC system 2, the power generation effect and the heating effect are achieved; through the waste heat exchanger 3, the coolant can achieve the effect of regulating the water supply temperature of the heating system. Combined with the power generation effect of the fuel cell 101, a second cogeneration operation state is provided.

The valve seven 7 is opened, the valve five 5 and the valve six 6 are closed, and the coolant enters the absorption refrigeration system 4. The cooling effect is achieved through the absorption refrigeration system 4. Combined with the power generation effect of the fuel cell 101, a first cooling and power cogeneration operation state is provided.

In the first cogeneration operation state, if there is excess coolant, the valve 6 is opened again to allow part of the coolant to enter the waste heat exchanger 3. Combining the power generation effect of the fuel cell 101, the cooling effect of the absorption refrigeration system 4 and the heating effect of the waste heat exchanger 3, the first cogeneration operation state is provided.

Valve five 5, valve six 6 and valve seven 7 are all opened, and the coolant enters the ORC system 2, the waste heat exchanger 3 and the absorption refrigeration system 4. The ORC system 2 achieves power generation and heating effects; the waste heat exchanger 3 achieves the effect of regulating the water supply temperature of the heating system; and the absorption refrigeration system 4 achieves cooling effects. Combined with the power generation effect of the fuel cell 101, a second combined heat and power operation state is provided.

Those skilled in the art can understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (6)

1. The operation method based on the fuel cell combined cooling heating and power system is characterized in that the fuel cell combined cooling heating and power system comprises a fuel cell system (1), an ORC system (2), a waste heat exchanger (3), an absorption refrigeration system (4) and a control system;

The fuel cell system (1) is used for generating electricity, the cooling liquid of the cooling system of the fuel cell system (1) respectively provides heat sources for the ORC system (2), the waste heat exchanger (3) and the absorption refrigeration system (4), the ORC system (2) can provide additional electric energy and first part of heat energy by being driven by the heat sources, the waste heat exchanger (3) can provide second part of heat energy, the absorption refrigeration system (4) can provide cold energy by being driven by the heat sources, and the cooling liquid after heat release flows back to the cooling system of the fuel cell system (1) to form circulation;

The control system is used for distributing cooling liquid supplied to the ORC system (2), the waste heat exchanger (3) and the absorption refrigeration system (4) according to the operation load of the fuel cell system (1) and the user demand, and controlling a heat supply mode to supply heat in a coordinated manner through the first part of heat energy and the second part of heat energy or supply heat independently through the second part of heat energy;

The pipeline for heat supply comprises a heat supply water return pipe (1011) and a heat supply water outlet pipe (1012) which are respectively connected with the user side; the heat supply return pipe (1011) is connected with a water side inlet of the ORC system condenser (204), a water side outlet of the ORC system condenser (204) is connected with a cold medium side inlet of the waste heat exchanger (3), and a cold medium side outlet of the waste heat exchanger (3) is connected with a heat supply outlet pipe (1012) to form a heat supply loop;

the cooling system of the fuel cell system (1) includes a liquid supply pipe (1006) and a liquid return pipe (1007) for the cooling liquid; the outlet of the liquid supply pipe (1006) is respectively connected with the heat source inlet of the ORC system evaporator (201) of the ORC system (2), the heat medium side inlet of the waste heat exchanger (3) and the heat source inlet of the generator (401) of the absorption refrigeration system (4), the connecting pipes are respectively provided with control valves, and the heat source outlet of the ORC system evaporator (201), the heat medium side outlet of the waste heat exchanger (3) and the heat source outlet of the generator (401) are respectively connected with the inlet of the liquid return pipe (1007) to form a cooling liquid loop;

The absorption refrigeration system (4) comprises a generator (401), a refrigeration system condenser (402), a refrigerant throttle valve (403), a refrigeration system evaporator (404), an absorber (405), a solution pump (406) and a solution throttle valve (407);

In the generator (401), the cooling liquid from the liquid supply pipe (1006) is used as a driving heat source to heat the dilute solution in the generator (401) so as to evaporate the refrigerant component in the solution and form high-temperature gaseous refrigerant;

The concentration of the dilute solution is increased to become concentrated solution, the concentrated solution enters an absorber (405) after being throttled and depressurized by a solution throttle valve (407), and the vaporized high-temperature gaseous refrigerant enters a condenser (402) of the refrigeration system;

In the refrigerating system condenser (402), the high-temperature gaseous refrigerant releases latent heat to cooling water of the refrigerating system condenser (402), and the high-temperature gaseous refrigerant is changed into liquid refrigerant, throttled and depressurized by a refrigerant throttle valve (403) and then enters an absorption refrigerating system evaporator (404);

The cooling water of the condenser (402) of the refrigeration system absorbs latent heat and then the temperature rises, and the heat is released to the outside of the system through an external heat radiating device;

the operation method comprises the following steps:

The fuel cell system (1) operates to supply power to a user;

When a user sends a heat supply request, the control system judges the operation load of the fuel cell system (1), and on the premise of meeting the operation load of the fuel cell system (1), according to the heat supply request temperature, the cooling liquid supply of the waste heat exchanger (3) is started, meanwhile, the cooling liquid supply of the ORC system (2) and the absorption refrigeration system (4) is cut off, the heat supply mode is switched to supply heat for the user independently through the second part of heat energy provided by the waste heat exchanger (3), or the cooling liquid supply of the waste heat exchanger (3) and the ORC system (2) is started, meanwhile, the cooling liquid supply of the absorption refrigeration system (4) is cut off, and the heat supply mode is switched to supply heat for the user through the cooperation of the first part of heat energy and the second part of heat energy;

When a user sends a cooling request, the control system judges the operation load of the fuel cell system (1), and on the premise of meeting the operation load of the fuel cell system (1), the cooling liquid supply of the absorption refrigeration system (4) is started, and meanwhile, the cooling liquid supply of the ORC system (2) and the waste heat exchanger (3) is cut off to cool the user; on the basis, a user sends a heat supply request, and on the premise of meeting the operating load of the fuel cell system (1), according to the heat supply request temperature, the cooling liquid supply of the waste heat exchanger (3) is started, the heat supply mode is to supply heat to the user independently through the second part of heat energy, or the cooling liquid supply of the waste heat exchanger (3) and the ORC system (2) is started, and the heat supply mode is to supply heat to the user through the cooperation of the first part of heat energy and the second part of heat energy;

When a user sends a cooling and heating request at the same time, the control system judges the operation load of the fuel cell system (1), and on the premise of meeting the operation load of the fuel cell system (1), the ORC system (2), the waste heat exchanger (3) and the cooling liquid supply of the absorption refrigeration system (4) are started at the same time, so that the combined cooling, heating and power supply is realized.

2. The method of operation according to claim 1, wherein a heating peak shaver (10) is connected in series to the heating outlet pipe (1012).

3. The operating method according to claim 1, characterized in that the cold supply line comprises a cold supply return pipe (1013) and a cold supply outlet pipe (1014) which are connected to the user side, respectively;

The cold supply return pipe (1013) is connected with a water side inlet of a refrigerating system evaporator (404) of the absorption refrigerating system (4), and a water side outlet of the refrigerating system evaporator (404) is connected with the cold supply outlet pipe (1014) to form a cold supply loop.

4. A method of operation according to claim 3, wherein the cold supply outlet pipe (1014) is further connected in series with a cold supply peak shaver (11).

5. The operating method according to claim 1, characterized in that the battery output circuit (1008) of the fuel cell system (1) is connected via an inverter (8) to a supply circuit (1010), the supply circuit (1010) being intended for connection to a user side, the supply circuit (1010) being provided with a voltage regulating device (9).

6. The operating method according to claim 5, characterized in that the ORC output circuit (1009) of the ORC system (2) is connected to a supply circuit (1010).