Fuel cell high-speed train waste heat utilization system and method thereof

Abstract

The invention belongs to the technical field of fuel cell application, and discloses a fuel cell high-speed train waste heat utilization system and a method thereof.The fuel cell high-speed train waste heat utilization system comprises a preheating water subsystem, a heating subsystem, an anti-freezing subsystem and a main heat dissipation subsystem; the water preheating subsystem preheats inlet water of a hot water supply device through a preheating heat exchanger by utilizing waste heat of a fuel cell, and hot water is provided for passengers; the heating subsystem heats air based on a heating radiator in a compartment through a heating heat exchanger by utilizing the waste heat of a fuel cell, and supplies heat to the compartment; the anti-freezing subsystem circulates preheated hot water to a clear water tank through a preheating heat exchanger by utilizing the waste heat of a fuel cell according to the needs in winter, so that a water filling nozzle is prevented from being frozen; and the residual heat of the fuel cell is borne by the main heat dissipation subsystem. The electric heating energy consumption of an existing hot water supply device is saved, the problems of compartment heating and water filling nozzle freezing prevention in winter are solved, the heat dissipation pressure and operation energy consumption of the high-power fuel cell are reduced, and the advantages of low cost and high efficiency are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fuel cell applications, in particular to a fuel cell high-speed train waste heat utilization system and method thereof. BACKGROUND

[0002] A hydrogen fuel cell is an energy conversion device that can continuously convert chemical energy into electrical energy through an electrochemical reaction as long as fuel (hydrogen) and oxidant (oxygen in air) are continuously supplied. The only emission during the process is water. It does not go through a heat engine process and is not limited by the "Carnot cycle" theory. The energy conversion efficiency of its electrochemical reaction is usually 40%-60%. If the waste heat generated by the reaction is recovered for combined heat and power, the total efficiency can even exceed 80% to 90%, which is much higher than that of internal combustion engines (usually 30% to 40%). Traditional trams or light rails require complex overhead contact systems and substation systems along the way, which have very high construction and maintenance costs. Fuel cell trains do not require overhead contact systems and can make full use of existing railways or newly built simple tracks, saving a large amount of infrastructure investment. A modern fuel cell tram can run more than 100 kilometers after a single hydrogen refueling, which is sufficient to meet the daily operation needs of most urban and regional lines. Fuel cell-powered urban rail vehicles are currently in the early stages of development both domestically and internationally.

[0003] Currently, there have been reports of fuel cell urban rail vehicles. For the utilization of fuel cell waste heat, a fuel cell waste heat utilization system and control method [CN119755697A] are proposed. To enable the generator to produce more electrical energy, a fuel cell waste heat utilization system and vehicle [CN117621766A] are proposed. To improve the temperature in the vehicle cabin in winter, a fuel cell vehicle thermal management system control method and vehicle [CN116176207A] are proposed. In summary, there are few ways to utilize fuel cell waste heat at present, and waste heat is not utilized for preheating water and preventing freezing of the water inlet in winter.

[0004] A fuel cell utilizes an electrochemical reaction to convert chemical energy into electrical energy. This reaction is an exothermic reaction that releases heat while generating electricity. Taking a fuel cell that uses hydrogen and oxygen as fuel and oxidant as an example, the heat released by the reaction is 484kJ / mol. If the fuel cell single-piece operating voltage is 0.75V (such as in the Barade HD6 system, the fuel cell single-piece operating voltage is basically at this level), the heat released by the fuel cell using hydrogen to generate electricity is basically equivalent to the power generated. That is, when the HD6 fuel cell system generates 150kW of electricity, the heat released is also close to 150kW, so the remaining heat must be released using a radiator to control the fuel cell to operate in an appropriate temperature range and ensure the working performance and safety of the fuel cell.

[0005] For fuel cell high-speed trains, heating and hot water systems are required to meet passenger comfort and water demand. In winter, the carriages require heating and passengers need hot water, with each carriage having a heat load of approximately 35kW. The waste heat from the fuel cells is sufficient for heating and preheating the carriages. Furthermore, the water inlet often freezes during winter water filling; utilizing the fuel cell's waste heat can prevent this. In other seasons, some of the fuel cell's waste heat is handled by the preheating system, with the remaining waste heat primarily handled by the main radiator. Currently, fuel cell vehicles often only have a main radiator; in winter, not only can the fuel cell's waste heat not be utilized, but a dedicated electric heater is needed to heat the carriages, and passenger hot water demand is high at this time. In summer, the ambient temperature is high, and the main radiator experiences high pressure, which the preheating system can handle. Moreover, compared to a traditional heating system, this system considers radiator heating for better comfort, and sharing the heating system with the air conditioning system increases energy consumption. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a waste heat utilization system and method for fuel cell high-speed trains, which effectively manages and utilizes the comprehensive heat from the fuel cell. While ensuring good heat dissipation and improving the performance of the fuel cell system, the system also considers comprehensive heat management. In winter, the waste heat from the fuel cell is used for heating the carriages, preheating water, and preventing the water inlet from freezing. In other seasons, the preheating system handles some of the waste heat, with the main radiator handling the heat dissipation. This achieves effective utilization of the heat from the entire vehicle system, energy saving, and improved system energy efficiency.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a fuel cell high-speed train waste heat utilization system, characterized in that it includes a fuel cell main heat dissipation subsystem, a heating subsystem, a preheating water subsystem, and an antifreeze subsystem; The main cooling subsystem includes a main cooling water pump MWP, a main radiator MR, and an electric three-way valve STV. The inlet of the main cooling water pump MWP is connected to the coolant outlet CO of the fuel cell stack FCS. The outlet pipeline of the main cooling water pump MWP is connected to the inlet of the electric three-way valve STV. The first outlet of the electric three-way valve STV is connected to the coolant inlet CI of the fuel cell stack FCS. The second outlet of the electric three-way valve STV is connected to the inlet of the main radiator MR via an electric valve SV1, and the outlet of the main radiator MR is connected to the coolant inlet CI of the fuel cell stack FCS. The heating subsystem includes a heating heat exchanger HE1, a heating circulation pump WP1, radiators HS, electric valves SV2 and SV4. The second outlet of the electric three-way valve STV is connected to the inlet of the primary side of the heating heat exchanger HE1 via the electric valve SV2, and the outlet of the primary side of the heating heat exchanger HE1 is connected to the coolant inlet CI of the fuel cell stack FCS. The radiators HS are connected to the secondary side of the heating heat exchanger HE1 via the heating circulation pump and the electric valve SV4. The preheating water subsystem includes a preheating heat exchanger HE2, a clean water tank WT1, an intermediate water tank WT2, a warm water tank WT3, an intermediate water tank variable speed pump WP2, a warm water tank variable speed pump WP3, an electric water heater WS, a washing subsystem EWH, and electric valves SV5, SV6, SV7, SV8, SV9, and SV10. The second outlet of the electric three-way valve STV is connected to the inlet of the primary side of the preheating heat exchanger HE2 via electric valve SV3, and the outlet of the primary side of the preheating heat exchanger HE2 is connected to the coolant inlet CI of the fuel cell stack FCS. The inlet pipe of the intermediate water tank variable speed pump WP2 is connected to the outlet of the clean water tank WT1, and the outlet pipe of the intermediate water tank variable speed pump WP2 is connected to the intermediate water tank WT1 via electric valve SV5. The water tank WT2 is connected to the water inlet. The water outlet of the intermediate water tank WT2 is connected to the inlet of the secondary side of the preheating heat exchanger HE2 via electric valve SV7. The outlet of the secondary side of the preheating heat exchanger HE2 is connected to the water inlet of the warm water tank WT3 via the warm water tank variable speed pump WP3. The water outlet of the warm water tank WT3 is connected to the inlet of the secondary side of the preheating heat exchanger HE2 via electric valve SV8. The water outlet of the warm water tank WT3 is connected to the water inlet of the electric water boiler WS via electric valve SV9, electric valve SV10 and filter F1. The cold water inlet of the washing subsystem EWH is connected to the water outlet of the intermediate water tank WT2 via electric valve SV6. The hot water inlet of the washing subsystem EWH is connected to the water outlet of the warm water tank WT3 via filter F2 and electric valves SV11 and SV9. In the antifreeze subsystem, the water inlet FO of the clean water tank is connected to the clean water tank WT1 via electric valve SV13, and the hot circulating water inlet of the clean water tank WT1 is connected to the outlet of the warm water tank WT3 via electric valves SV12 and SV9.

[0008] Furthermore, the system also includes: temperature sensors TT1 and TT2 are respectively installed at the coolant outlet CO and inlet CI of the fuel cell stack FCS; temperature sensor TT3 is installed on the secondary side of the heating heat exchanger; water level sensor WL1 is installed in the intermediate water tank WT2; temperature sensor TT4 is installed on the secondary side of the preheating heat exchanger; water level sensor WL2 and temperature sensor TT5 are installed in the warm water tank WT3; and a central controller is also provided. The signal terminals of each temperature sensor and water level sensor are connected to the central controller, which is also interconnected with the control terminals of each electric valve, the water pump control terminal, and the fan control terminal in the main radiator.

[0009] On the other hand, based on the aforementioned waste heat utilization system for fuel cell high-speed trains, this invention also provides a method for utilizing waste heat from fuel cell high-speed trains, comprising: opening or closing heat exchanger valves SV2 and / or SV3 according to different seasonal needs to operate or deactivate the heating subsystem or preheating water subsystem and antifreeze subsystem; in winter, the waste heat from the fuel cell stack FCS is used to heat the carriages and provide hot water through the heating subsystem, preheating water subsystem, and antifreeze subsystem, while preventing the water inlet from freezing during water injection; in summer, the main radiator MR dissipates heat from the fuel cell stack FCS, with the preheating water subsystem providing auxiliary heat dissipation; thus achieving comprehensive heat management of the fuel cell stack FCS and the heating subsystem, preheating water subsystem, and antifreeze subsystem. The preheating subsystem uses the waste heat from the fuel cell to preheat the incoming water of the hot water supply device through a preheating heat exchanger to provide hot water for passengers; the heating subsystem uses the waste heat from the fuel cell to heat the air in the carriage through the radiators in the carriage through a heating heat exchanger to provide heating for the carriage; the antifreeze subsystem circulates the preheated hot water to the clean water tank through the preheating heat exchanger as needed in winter to prevent the water inlet from freezing; the remaining waste heat from the fuel cell is handled by the main heat dissipation subsystem; each subsystem is automatically controlled by the central controller.

[0010] Furthermore, the control strategy under winter operating conditions is as follows: the main radiator valve SV1, the heating heat exchanger valve SV2, and the preheating heat exchanger valve SV3 are opened simultaneously; the temperature is detected by temperature sensors TT3 and TT4, and the opening degree of the heating heat exchanger valve SV2 and the preheating heat exchanger valve SV3 is controlled by the central controller so that the secondary side of the heating heat exchanger and the preheating heat exchanger reaches the preset temperature; after the opening degree of the heating heat exchanger valve SV2 and the preheating heat exchanger valve SV3 is set, the main radiator fan speed is controlled to keep the fuel cell stack FCS coolant inlet temperature within the preset temperature range.

[0011] Furthermore, the control strategy under summer operating conditions is as follows: the heating heat exchanger valve SV2 is closed, while the main radiator valve SV1 and the preheating heat exchanger valve SV3 are opened; the temperature is detected by the temperature sensor TT4, and the opening degree of the preheating heat exchanger valve SV3 is controlled by the central controller to ensure that the secondary side of the preheating heat exchanger reaches the preset temperature; after the opening degree of the preheating heat exchanger valve SV3 is set, the main radiator fan speed is controlled to ensure that the inlet temperature of the fuel cell stack FCS coolant is within the preset temperature range.

[0012] Furthermore, the control strategy of the heating subsystem is as follows: the temperature is detected by the temperature sensor inside the carriage, and the speed of valve SV4 and water pump WP1 is controlled by the central controller.

[0013] Furthermore, the control strategy of the preheating water subsystem is as follows: the clear water tank WT1 injects water into the intermediate water tank WT2 through the water pump WP2 and valve SV5. The intermediate water tank WT2 heats the water through the secondary side of the preheating heat exchanger HE2 via valve SV7, and then injects water into the warm water tank WT3 through the water pump WP3. When the water temperature in the warm water tank WT3 is insufficient, the speed of valve SV8 and water pump WP3 is controlled to start a small circulation until the water temperature in the warm water tank WT3 returns to the preset temperature range. When the electric water heater WS needs hot water, valves SV9 and S10 are opened to inject water into the electric water heater WS. When the washing subsystem EWH needs hot water, valves SV9 and SV11 are opened, and the output water temperature is controlled by the opening degree of valve SV6. Filters F1 and F2 filter the water. Valve SV5 and valve SV7 are controlled by the signals of water level sensors WL1 and WL2, respectively, through the central controller.

[0014] Furthermore, the control strategy of the antifreeze subsystem is as follows: when the train is filled with water in winter, in order to prevent the water inlet FO from freezing, valve SV12 is opened in advance to allow hot water to circulate to the clean water tank WT1. When filling with water, valve SV13 is opened first to allow some hot water to flow out to melt the ice in the water inlet FO.

[0015] The beneficial effects of adopting this technical solution are: This invention proposes a method for utilizing waste heat from fuel cell high-speed trains. The method adjusts the operating state of the fuel cell radiator assembly, consisting of the main radiator, heating heat exchanger, and preheating heat exchanger, according to the ambient temperature. This rationally and fully utilizes the waste heat from the fuel cell, achieving comprehensive utilization of the heat of the entire vehicle system and improving system energy efficiency. In winter, the heating heat exchanger, preheating heat exchanger, and main radiator work together to dissipate heat from the fuel cell. This improves heat dissipation capacity, reduces the power consumption and noise pollution of the main radiator, and the fuel cell waste heat can be directly used for heating the carriages and providing hot water. This fully utilizes the fuel cell waste heat without requiring an air conditioning system for heating, saving energy consumption of the existing hot water system. It also solves the problem of freezing the water inlet in winter and reduces the heat dissipation pressure, operating energy consumption, and cost of the fuel cell radiator. Attached Figure Description

[0016] Figure 1 This is a general topology diagram of a fuel cell high-speed train waste heat utilization system according to the present invention; Figure 2 The control flowchart of the heating subsystem and preheating water subsystem under winter conditions implemented in this invention Figure 3 This is a control flowchart for the preheating subsystem under other operating conditions in the implementation of this invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings.

[0018] In this embodiment, see Figure 1 As shown, the present invention proposes a waste heat utilization system for fuel cell high-speed trains, including a fuel cell main heat dissipation subsystem, a heating subsystem, a preheating water subsystem, and an antifreeze subsystem.

[0019] The main cooling subsystem includes a main cooling water pump MWP, a main radiator MR, and an electric three-way valve STV. The inlet of the main cooling water pump MWP is connected to the coolant outlet CO of the fuel cell stack FCS. The outlet pipeline of the main cooling water pump MWP is connected to the inlet of the electric three-way valve STV. The first outlet of the electric three-way valve STV is connected to the coolant inlet CI of the fuel cell stack FCS. The second outlet of the electric three-way valve STV is connected to the inlet of the main radiator MR via an electric valve SV1, and the outlet of the main radiator MR is connected to the coolant inlet CI of the fuel cell stack FCS.

[0020] The heating subsystem includes a heating heat exchanger HE1, a heating circulation pump WP1, radiators HS, electric valves SV2 and SV4. The second outlet of the electric three-way valve STV is connected to the inlet of the primary side of the heating heat exchanger HE1 via electric valve SV2, and the outlet of the primary side of the heating heat exchanger HE1 is connected to the coolant inlet CI of the fuel cell stack FCS. The radiators HS are connected to the secondary side of the heating heat exchanger HE1 via the heating circulation pump and electric valve SV4.

[0021] The preheating water subsystem includes a preheating heat exchanger HE2, a clean water tank WT1, an intermediate water tank WT2, a warm water tank WT3, an intermediate water tank variable speed pump WP2, a warm water tank variable speed pump WP3, an electric water heater WS, a washing subsystem EWH, and electric valves SV5, SV6, SV7, SV8, SV9, and SV10. The second outlet of the electric three-way valve STV is connected to the inlet of the primary side of the preheating heat exchanger HE2 via electric valve SV3, and the outlet of the primary side of the preheating heat exchanger HE2 is connected to the coolant inlet CI of the fuel cell stack FCS. The inlet pipe of the intermediate water tank variable speed pump WP2 is connected to the outlet of the clean water tank WT1, and the outlet pipe of the intermediate water tank variable speed pump WP2 is connected to the intermediate water tank WT1 via electric valve SV5. The water inlet of water tank WT2 is connected. The outlet of intermediate water tank WT2 is connected to the inlet of the secondary side of preheating heat exchanger HE2 via electric valve SV7. The outlet of the secondary side of preheating heat exchanger HE2 is connected to the inlet of warm water tank WT3 via warm water tank variable speed pump WP3. The outlet of warm water tank WT3 is connected to the inlet of the secondary side of preheating heat exchanger HE2 via electric valve SV8. The outlet of warm water tank WT3 is connected to the water inlet of electric water boiler WS via electric valve SV9, electric valve SV10 and filter F1. The cold water inlet of washing subsystem EWH is connected to the outlet of intermediate water tank WT2 via electric valve SV6. The hot water inlet of washing subsystem EWH is connected to the outlet of warm water tank WT3 via filter F2 and electric valves SV11 and SV9.

[0022] In the antifreeze subsystem, the water inlet FO of the clean water tank is connected to the clean water tank WT1 via electric valve SV13, and the hot circulating water inlet of the clean water tank WT1 is connected to the outlet of the warm water tank WT3 via electric valves SV12 and SV9.

[0023] Temperature sensors TT1 and TT2 are installed at the coolant outlet CO and inlet CI of the fuel cell stack FCS, respectively. Temperature sensor TT3 is installed on the secondary side of the heating heat exchanger. Water level sensor WL1 is installed in the intermediate water tank WT2. Temperature sensor TT4 is installed on the secondary side of the preheating heat exchanger. Water level sensor WL2 and temperature sensor TT5 are installed in the warm water tank WT3. A central controller is also provided. The signal terminals of each temperature sensor and water level sensor are connected to the central controller. The central controller is also interconnected with the control terminals of each electric valve, the water pump control terminal, and the fan control terminal in the main radiator.

[0024] The waste heat utilization central controller of this invention collects signals from sensors such as the fuel cell coolant outlet temperature sensor, fuel cell coolant inlet temperature sensor, secondary side temperature of the heating heat exchanger, ambient temperature sensor of the vehicle compartment, secondary side temperature of the preheating heat exchanger, water level sensor of the intermediate water tank, and temperature and water level sensor of the warm water tank. It is used to control the opening and closing of valve groups of electric three-way valve, heating heat exchanger valve, preheating heat exchanger valve, main radiator valve, heating subsystem valve, preheating water subsystem and antifreeze subsystem valve groups, as well as the start, stop and speed of the coolant circulation pump, intermediate water tank variable speed pump, warm water tank variable speed pump and main radiator fan.

[0025] Preferably, the main radiator employs an active cooling method with a fan, and it is recommended to use an intake airflow organization, where air first passes through the heat sink and then is exhausted by the cooling fan. The main radiator design must ensure its heat dissipation capacity to meet the heat dissipation requirements of the fuel cell under any operating conditions.

[0026] The heating radiators are preferably located under the seats on both sides of the carriage walls to provide heating and ensure comfort. The heating radiators and antifreeze subsystem operate only in winter conditions. In winter, the heating heat exchanger, preheating heat exchanger, and main radiator are in operation. The waste heat from the fuel cell can be directly used for heating the carriage, providing hot water for passengers, and preventing the water inlet from freezing. In conjunction with the fuel cell main radiator, it can provide efficient cooling for the fuel cell to ensure its optimal performance, while also providing effective heating for the carriage, achieving full utilization of heat.

[0027] The waste heat utilization device of the present invention consists of a heat exchanger, a heating subsystem, a preheating water subsystem, and an antifreeze subsystem. The heat exchanger is connected by pipes, and its connection topology is as follows: the coolant inlets and outlets of all heat exchangers are connected in parallel, or the heating subsystem, the preheating water subsystem, and the antifreeze subsystem are connected in parallel and then connected in parallel with the main radiator.

[0028] To facilitate the implementation of the aforementioned system, based on the same inventive concept, this invention also provides a method for utilizing waste heat from a fuel cell high-speed train, based on the aforementioned fuel cell high-speed train waste heat utilization system. This method includes: opening or closing heat exchanger valves SV2 and / or SV3 according to different seasonal needs to operate or deactivate the heating subsystem, preheating subsystem, and antifreeze subsystem; in winter, the waste heat from the fuel cell stack (FCS) is used to heat the carriages and provide hot water through the heating subsystem, preheating subsystem, and antifreeze subsystem, while preventing the water inlet from freezing during water injection; in summer, the main radiator MR dissipates heat from the fuel cell stack (FCS), with the preheating subsystem providing auxiliary heat dissipation; thus achieving comprehensive heat management of the fuel cell stack (FCS) and the heating, preheating, and antifreeze subsystems.

[0029] The preheating subsystem uses the waste heat from the fuel cell to preheat the incoming water of the hot water supply device through a preheating heat exchanger to provide hot water for passengers; the heating subsystem uses the waste heat from the fuel cell to heat the air in the carriage through the radiators in the carriage through a heating heat exchanger to provide heating for the carriage; the antifreeze subsystem circulates the preheated hot water to the clean water tank through the preheating heat exchanger as needed in winter to prevent the water inlet from freezing; the remaining waste heat from the fuel cell is handled by the main heat dissipation subsystem; each subsystem is automatically controlled by the central controller.

[0030] like Figure 2 As shown, the control strategy under winter operating conditions is as follows: the main radiator valve SV1, the heating heat exchanger valve SV2, and the preheating heat exchanger valve SV3 are opened simultaneously; the temperature is detected by temperature sensors TT3 and TT4, and the opening degree of the heating heat exchanger valve SV2 and the preheating heat exchanger valve SV3 is controlled by the central controller so that the secondary side of the heating heat exchanger and the preheating heat exchanger reaches the preset temperature; after the opening degree of the heating heat exchanger valve SV2 and the preheating heat exchanger valve SV3 is set, the main radiator fan speed is controlled so that the inlet temperature of the fuel cell stack FCS coolant is within the preset temperature range (55~63℃).

[0031] The control strategy under summer operating conditions is as follows: close the heating heat exchanger valve SV2, and simultaneously open the main radiator valve SV1 and the preheating heat exchanger valve SV3; the temperature is detected by the temperature sensor TT4, and the opening degree of the preheating heat exchanger valve SV3 is controlled by the central controller to make the secondary side of the preheating heat exchanger reach the preset temperature; after the opening degree of the preheating heat exchanger valve SV3 is set, the main radiator fan speed is controlled to make the inlet temperature of the fuel cell stack FCS coolant within the preset temperature range (55~63℃).

[0032] The control strategy of the heating subsystem is as follows: when the temperature inside the carriage is below 25°C, the valve SV4 is opened to its maximum. If the valve SV4 is already at its maximum opening, the water pump WP1 is controlled to increase the water flow until the temperature inside the carriage reaches 25°C. The valve SV4 and the water pump WP1 are then adjusted to stabilize the temperature inside the carriage at 25°C.

[0033] like Figure 3As shown, the control strategy of the preheating water subsystem is as follows: the clear water tank WT1 injects water into the intermediate water tank WT2 through the water pump WP2 and valve SV5. The intermediate water tank WT2 heats the water through the secondary side of the preheating heat exchanger HE2 through valve SV7, and then injects water into the warm water tank WT3 through the water pump WP3. When the water temperature in the warm water tank WT3 is lower than 40℃, the speed of valve SV8 and water pump WP3 is controlled to start a small circulation until the water temperature in the warm water tank WT3 recovers to about 40℃. When the electric water heater WS needs hot water, valves SV9 and S10 are opened to inject water into the electric water heater WS. When the washing subsystem EWH needs hot water, valves SV9 and SV11 are opened, and the output water temperature is controlled by the opening degree of valve SV6. Filters F1 and F2 filter the water. Valve SV5 and valve SV7 are controlled by the signals of water level sensors WL1 and WL2, respectively, through the central controller.

[0034] The control strategy of the antifreeze subsystem is as follows: In winter, when the train is filled with water, in order to prevent the water inlet FO from freezing, valve SV12 is opened in advance to allow hot water to circulate to the clean water tank WT1. When filling with water, valve SV13 is opened first to allow some hot water to flow out to melt the ice in the water inlet FO.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery system for fuel cell high-speed trains, characterized in that, This includes the fuel cell main heat dissipation subsystem, heating subsystem, preheating water subsystem, and antifreeze subsystem; The main cooling subsystem includes a main cooling water pump MWP, a main radiator MR, and an electric three-way valve STV. The inlet of the main cooling water pump MWP is connected to the coolant outlet CO of the fuel cell stack FCS. The outlet pipeline of the main cooling water pump MWP is connected to the inlet of the electric three-way valve STV. The first outlet of the electric three-way valve STV is connected to the coolant inlet CI of the fuel cell stack FCS. The second outlet of the electric three-way valve STV is connected to the inlet of the main radiator MR via an electric valve SV1, and the outlet of the main radiator MR is connected to the coolant inlet CI of the fuel cell stack FCS. The heating subsystem includes a heating heat exchanger HE1, a heating circulation pump WP1, radiators HS, electric valves SV2 and SV4. The second outlet of the electric three-way valve STV is connected to the inlet of the primary side of the heating heat exchanger HE1 via the electric valve SV2, and the outlet of the primary side of the heating heat exchanger HE1 is connected to the coolant inlet CI of the fuel cell stack FCS. The radiators HS are connected to the secondary side of the heating heat exchanger HE1 via the heating circulation pump and the electric valve SV4. The preheating water subsystem includes a preheating heat exchanger HE2, a clean water tank WT1, an intermediate water tank WT2, a warm water tank WT3, an intermediate water tank variable speed pump WP2, a warm water tank variable speed pump WP3, an electric water heater WS, a washing subsystem EWH, and electric valves SV5, SV6, SV7, SV8, SV9, and SV10. The second outlet of the electric three-way valve STV is connected to the inlet of the primary side of the preheating heat exchanger HE2 via electric valve SV3, and the outlet of the primary side of the preheating heat exchanger HE2 is connected to the coolant inlet CI of the fuel cell stack FCS. The inlet pipe of the intermediate water tank variable speed pump WP2 is connected to the outlet of the clean water tank WT1, and the outlet pipe of the intermediate water tank variable speed pump WP2 is connected to the intermediate water tank WT1 via electric valve SV5. The water tank WT2 is connected to the water inlet. The water outlet of the intermediate water tank WT2 is connected to the inlet of the secondary side of the preheating heat exchanger HE2 via electric valve SV7. The outlet of the secondary side of the preheating heat exchanger HE2 is connected to the water inlet of the warm water tank WT3 via the warm water tank variable speed pump WP3. The water outlet of the warm water tank WT3 is connected to the inlet of the secondary side of the preheating heat exchanger HE2 via electric valve SV8. The water outlet of the warm water tank WT3 is connected to the water inlet of the electric water boiler WS via electric valve SV9, electric valve SV10 and filter F1. The cold water inlet of the washing subsystem EWH is connected to the water outlet of the intermediate water tank WT2 via electric valve SV6. The hot water inlet of the washing subsystem EWH is connected to the water outlet of the warm water tank WT3 via filter F2 and electric valves SV11 and SV9. In the antifreeze subsystem, the water inlet FO of the clean water tank is connected to the clean water tank WT1 via electric valve SV13, and the hot circulating water inlet of the clean water tank WT1 is connected to the outlet of the warm water tank WT3 via electric valves SV12 and SV9.

2. The waste heat recovery system for fuel cell high-speed trains according to claim 1, characterized in that, Also includes: Temperature sensors TT1 and TT2 are installed at the coolant outlet CO and inlet CI of the fuel cell stack FCS, respectively. Temperature sensor TT3 is installed on the secondary side of the heating heat exchanger. Water level sensor WL1 is installed in the intermediate water tank WT2. Temperature sensor TT4 is installed on the secondary side of the preheating heat exchanger. Water level sensor WL2 and temperature sensor TT5 are installed in the warm water tank WT3. A central controller is also provided. The signal terminals of each temperature sensor and water level sensor are connected to the central controller. The central controller is also interconnected with the control terminals of each electric valve, the water pump control terminal, and the fan control terminal in the main radiator.

3. A method for utilizing waste heat from fuel cell high-speed trains, characterized in that, A waste heat utilization system for fuel cell high-speed trains based on claim 1 or 2 includes: opening or closing heat exchanger valves SV2 and / or SV3 to operate or deactivate the heating subsystem or preheating subsystem and antifreeze subsystem according to different seasonal needs; in winter, the waste heat from the fuel cell stack (FCS) is used to heat the carriages and provide hot water through the heating subsystem, preheating subsystem, and antifreeze subsystem, while preventing the water inlet from freezing during water filling; in summer, the main radiator MR dissipates heat from the fuel cell stack (FCS), with the preheating subsystem providing auxiliary heat dissipation; achieving comprehensive heat management of the fuel cell stack (FCS) and the heating subsystem, preheating subsystem, and antifreeze subsystem. The preheating subsystem uses the waste heat from the fuel cell to preheat the incoming water of the hot water supply device through a preheating heat exchanger to provide hot water for passengers; the heating subsystem uses the waste heat from the fuel cell to heat the air in the carriage through the radiators in the carriage through a heating heat exchanger to provide heating for the carriage; the antifreeze subsystem circulates the preheated hot water to the clean water tank through the preheating heat exchanger as needed in winter to prevent the water inlet from freezing; the remaining waste heat from the fuel cell is handled by the main heat dissipation subsystem; each subsystem is automatically controlled by the central controller.

4. The method for utilizing waste heat from a fuel cell high-speed train according to claim 3, characterized in that, The control strategy under winter operating conditions is as follows: simultaneously open the main radiator valve SV1, the heating heat exchanger valve SV2, and the preheating heat exchanger valve SV3; temperature is detected by temperature sensors TT3 and TT4, and the opening degree of the heating heat exchanger valve SV2 and the preheating heat exchanger valve SV3 is controlled by the central controller to ensure that the secondary side of the heating heat exchanger and the preheating heat exchanger reaches the preset temperature; after the opening degree of the heating heat exchanger valve SV2 and the preheating heat exchanger valve SV3 is set, the main radiator fan speed is controlled to ensure that the inlet temperature of the fuel cell stack FCS coolant is within the preset temperature range.

5. A method for utilizing waste heat from a fuel cell high-speed train according to claim 3, characterized in that, The control strategy under summer operating conditions is as follows: close the heating heat exchanger valve SV2, and simultaneously open the main radiator valve SV1 and the preheating heat exchanger valve SV3; the temperature is detected by the temperature sensor TT4, and the opening degree of the preheating heat exchanger valve SV3 is controlled by the central controller to make the secondary side of the preheating heat exchanger reach the preset temperature; after the opening degree of the preheating heat exchanger valve SV3 is set, the main radiator fan speed is controlled to keep the inlet temperature of the fuel cell stack FCS coolant within the preset temperature range.

6. A method for utilizing waste heat from a fuel cell high-speed train according to claim 3, characterized in that, The control strategy of the heating subsystem is as follows: the temperature is detected by the temperature sensor inside the carriage, and the speed of valve SV4 and water pump WP1 is controlled by the central controller.

7. A method for utilizing waste heat from a fuel cell high-speed train according to claim 3, characterized in that, The control strategy of the preheating water subsystem is as follows: the clear water tank WT1 injects water into the intermediate water tank WT2 through the water pump WP2 and valve SV5. The intermediate water tank WT2 heats the water through the secondary side of the preheating heat exchanger HE2 through valve SV7, and then injects water into the warm water tank WT3 through the water pump WP3. When the water temperature in the warm water tank WT3 is insufficient, the speed of valve SV8 and water pump WP3 is controlled to start a small circulation until the water temperature in the warm water tank WT3 returns to the preset temperature range. When the electric water heater WS needs hot water, valves SV9 and S10 are opened to inject water into the electric water heater WS. When the washing subsystem EWH needs hot water, valves SV9 and SV11 are opened, and the output water temperature is controlled by the opening degree of valve SV6. Filters F1 and F2 filter the water. Valve SV5 and valve SV7 are controlled by the signals of water level sensors WL1 and WL2, respectively, through the central controller.

8. A method for utilizing waste heat from a fuel cell high-speed train according to claim 3, characterized in that, The control strategy of the antifreeze subsystem is as follows: In winter, when the train is filled with water, in order to prevent the water inlet FO from freezing, valve SV12 is opened in advance to allow hot water to circulate to the clean water tank WT1. When filling with water, valve SV13 is opened first to allow some hot water to flow out to melt the ice in the water inlet FO.

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