A hydrothermal system for a fuel cell

Abstract

The application discloses a hydrothermal system of a fuel cell, which comprises a liquid circulation loop, a water pump, a first radiator, a second radiator, a heater, an intercooler, a three-way valve and a four-way valve, and the first radiator, the second radiator and the heater are connected in parallel to the liquid circulation loop. The liquid circulation loop further comprises a bypass connected in parallel to the first radiator, the second radiator and the heater. The three-way valve comprises one inlet end and two outlet ends, and the four-way valve comprises two inlet ends and two outlet ends. The inlet end of the three-way valve and one inlet end of the four-way valve are connected to an outlet after the electric pile of the liquid circulation loop, the other inlet end of the four-way valve is connected to the intercooler, and the four outlet ends formed by the three-way valve and the four-way valve are connected to the first radiator, the second radiator, the heater and the bypass one by one. The application can meet the temperature adjustment requirements of the fuel cell under various working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell technology, and in particular to a water and heat system of a fuel cell. BACKGROUND

[0002] Fuel cell has multiple operating conditions, when its temperature is low, it needs to be warmed up, when its temperature is high, it needs to be cooled. The control of fuel cell temperature is realized by water and heat system. A water and heat system in the prior art has a parallel path with the heating element when performing normal warming work, so that part of the liquid is not heated, and the warming speed is slow. Moreover, the control mode of the water and heat system in the prior art is relatively single, usually only one warming and one cooling mode, which is difficult to meet the temperature regulation requirements of multiple different conditions.

[0003] Therefore, the prior art needs to be improved. SUMMARY

[0004] In order to overcome the defects of the prior art, the present application provides a water and heat system of a fuel cell, which has high warming efficiency and multiple operating modes to meet the temperature regulation requirements of multiple different conditions.

[0005] The present application is realized by the following technical scheme: a water and heat system of a fuel cell, comprising a liquid circulation loop, the liquid circulation loop passes through the stack of the fuel cell to adjust the temperature of the stack, a water pump, a first radiator, a second radiator, a heater, an intercooler, a three-way valve and a four-way valve are connected to the liquid circulation loop, the first radiator, the second radiator and the heater are connected in parallel to the liquid circulation loop, the liquid circulation loop further comprises a bypass connected in parallel to the first radiator, the second radiator and the heater, the three-way valve comprises one inlet end and two outlet ends, the four-way valve comprises two inlet ends and two outlet ends, the inlet end of the three-way valve and one inlet end of the four-way valve are connected to the outlet of the liquid circulation loop after the stack, the other inlet end of the four-way valve is connected to the intercooler, and the four outlet ends formed by the three-way valve and the four-way valve are connected to the first radiator, the second radiator, the heater and the bypass one by one.

[0006] Optionally, the three-way valve is an electronic throttle valve, the first radiator is connected to one outlet end of the three-way valve, and the second radiator is connected to one outlet end of the four-way valve.

[0007] Optionally, the heat dissipation capacity of the first radiator is greater than that of the second radiator.

[0008] Optionally, the first radiator is a front-mounted radiator, and the second radiator is a side-mounted radiator.

[0009] Optionally, the first radiator and the heater are connected to two outlet ends of the three-way valve one by one, and the second radiator and the bypass are connected to two outlet ends of the four-way valve one by one.

[0010] Optionally, the on-off and opening size of the two outlet ends of the three-way valve are controllably associated, the on-off and opening size of the two outlet ends of the four-way valve are controllably associated, and the on-off and opening relationship between the three-way valve and the four-way valve is controllably independent.

[0011] Optionally, the liquid circulation loop further comprises a deionizer connected in parallel with the intercooler, and the inlet ends of the intercooler and the deionizer are connected to the inlet of the liquid circulation loop before entering the stack, and the outlet ends of the intercooler and the deionizer are connected to one inlet end of the four-way valve.

[0012] Optionally, the four-way valve comprises a single valve component with four ports, or a single valve component with more than four ports and four ports connected to the liquid circulation loop, or a combined valve component formed by connecting two three-way valves.

[0013] Optionally, first to third temperature sensors are arranged on the liquid circulation loop, the first temperature sensor is connected to the outlet after the first radiator and the second radiator are connected in parallel, the second temperature sensor is connected to the inlet of the liquid circulation loop before entering the stack, and the third temperature sensor is connected to the outlet of the liquid circulation loop after leaving the stack.

[0014] Optionally, the water heat system further comprises a waste heat utilization branch, the front end of the waste heat utilization branch is connected to the outlet of the liquid circulation loop after leaving the stack, and the rear end is connected to the water pump.

[0015] The water heat system of the fuel cell provided by the application is provided with two radiators, and the first radiator, the second radiator, the heater and the bypass are connected in parallel in the liquid circulation loop through the arrangement of the three-way valve and the four-way valve, so that the water heat system can meet the operation modes of cold start warm-up, normal warm-up, transition stage, low heat dissipation demand and high heat dissipation demand, and meet the temperature regulation demand under various working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the system diagram of the water heat system of the fuel cell.

[0017] The reference signs are as follows: 1 - stack; 2 - water pump; 3 - first radiator; 4 - second radiator; 5 - heater; 6 - intercooler; 7 - deionizer; 8 - three-way valve; 9 - four-way valve; 91 - bypass; 10 - water tank. DETAILED DESCRIPTION

[0018] In order to make the technical features, objectives and effects of the present application more clearly understood, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0020] As shown in FIG. 1, Figure 1 The present application provides a hydrothermal system of a fuel cell, which comprises a liquid circulation loop passing through a stack 1 of the fuel cell to regulate the temperature of the stack 1. A water pump 2, a first radiator 3, a second radiator 4, a heater 5, an intercooler 6, a three-way valve 8 and a four-way valve 9 are connected to the liquid circulation loop. The first radiator 3, the second radiator 4 and the heater 5 are connected in parallel to the liquid circulation loop. The liquid circulation loop further comprises a bypass 91 connected in parallel to the first radiator 3, the second radiator 4 and the heater 5. The three-way valve 8 comprises one inlet end (port f as shown in the figure) and two outlet ends (ports a and b as shown in the figure), and the four-way valve 9 comprises two inlet ends (ports f and c as shown in the figure) and two outlet ends (ports e and d as shown in the figure). The inlet end of the three-way valve 8 and one inlet end of the four-way valve 9 are respectively connected to the outlet of the liquid circulation loop after the stack 1, and the other inlet end of the four-way valve 9 is connected to the intercooler 6. The four outlet ends formed by the three-way valve 8 and the four-way valve 9 are respectively connected to the first radiator 3, the second radiator 4, the heater 5 and the bypass 91. In this way, the first radiator 3, the second radiator 4, the heater 5 and the intercooler 6 are connected to the liquid circulation loop through the three-way valve 8 and / or the four-way valve 9, and form relatively independent first radiator branch, second radiator branch, heater branch and intercooler branch. By controlling the opening and closing and the opening degree of each port of the three-way valve 8 and the four-way valve 9, the connection of different branches to the liquid circulation loop can be realized to adapt to different working conditions.

[0021] As shown in FIG. 2, Figure 1 The three-way valve 8 is an electronic throttle valve ETV, the first radiator 3 is connected to one outlet end of the three-way valve 8, and the second radiator 4 is connected to one outlet end of the four-way valve 9. Figure 1In the illustrated embodiment, the first radiator 3 is connected to port b of the three-way valve 8, and the second radiator 4 is connected to port d of the four-way valve 9. Since the three-way valve 8 and the four-way valve 9 are two relatively independent valves, the connection of the two radiators to these two independent valves ensures that the connection and opening degree of the first radiator 3 and the second radiator 4 do not affect each other. The user can choose to connect one of them to the circulation loop or both of them to the circulation loop simultaneously, depending on the actual working conditions.

[0022] Optionally, the heat dissipation capacity of the first radiator 3 is greater than that of the second radiator 4. The first radiator 3 is a front-mounted radiator, and the second radiator 4 is a side-mounted radiator.

[0023] Please continue reading. Figure 1 As shown, the first radiator 3 and the heater 5 are connected one-to-one to the two outlet ends of the three-way valve 8. Figure 1 In the illustrated embodiment, the first radiator 3 is connected to port b of the three-way valve 8, and the heater 5 is connected to port a of the three-way valve 8. The on / off state and opening size of the two outlets of the three-way valve 8 are correlated and adjustable. The connection of the heater 5 and the connection of the first radiator 3 are often inversely related; that is, when the liquid circulation loop needs to be connected to the heater 5 for heating, the first radiator 3 is often not needed for heat dissipation; conversely, when the first radiator 3 is needed for heat dissipation, the heater 5 is often not needed. Therefore, by connecting the first radiator 3 and the heater 5 to the two outlets of the same three-way valve 8, the inherent opening relationship of the three-way valve 8 allows for coordinated control of whether the first radiator 3 and the heater 5 are connected and the size of their connection opening, which simplifies the control logic and increases the stability of the system operation. In one embodiment, the heater 5 is a PTC heater.

[0024] Furthermore, the second radiator 4 and the bypass passage 91 are connected one-to-one to the two outlet ends, namely port d and port e, of the four-way valve 9. The bypass passage 91 is mainly used to form a loop when needed, and the second radiator 4 is used to dissipate heat from the liquid circulation loop together with the first radiator 3 when there is a high demand for heat dissipation. The on / off state and opening size of the two outlet ends of the four-way valve 9 are controlled in a correlated and adjustable manner. The on / off state and opening degree relationship between the three-way valve 8 and the four-way valve 9 are individually adjustable and controllable.

[0025] Please continue reading. Figure 1 As shown, the liquid circulation loop also includes a deionizer 7 connected in parallel with the intercooler 6. The inlet ends of the intercooler 6 and the deionizer 7 are connected to the inlet of the liquid circulation loop before entering the fuel cell stack 1, and the outlet ends of the intercooler 6 and the deionizer 7 are connected to one inlet end of the four-way valve 9. Figure 1The c-port is shown in FIG. 1. The intercooler 6 is used to introduce the heat exchanged with the compressed air into the water-heat system to realize energy utilization. The deionizer 7 is used to remove the ions in the liquid in the liquid circulation loop to avoid adversely affecting the chemical reaction on the stack 1.

[0026] It should be noted that the four-way valve 9 includes a single valve component with four ports, or a single valve component with more than four ports and four of which are connected to the liquid circulation loop, or a combined valve component connected by two three-way valves. That is, the four-way valve 9 has at least four ports, which includes the case of using a five-way, six-way, etc. as a four-way valve.

[0027] Further, the liquid circulation loop is provided with first, second and third temperature sensors T30, T32, T33. The first temperature sensor T30 is connected to the outlet after the first radiator 3 and the second radiator 4 are connected in parallel, the second temperature sensor T32 is connected to the inlet before the liquid circulation loop enters the stack 1, and the third temperature sensor T33 is connected to the outlet after the liquid circulation loop exits the stack 1. The operating conditions of the fuel cell are determined by the temperatures detected by the first, second and third temperature sensors T30, T32, T33.

[0028] Further, the water-heat system further includes a waste heat utilization branch (not shown in the figure), the front end of which is connected to the outlet after the liquid circulation loop exits the stack 1, and the rear end is connected to the water pump 2. The water-heat system further includes a water tank 10 and an exhaust passage for exhausting the gas in the liquid circulation loop to the water tank 10.

[0029] Please continue to see Figure 1 The control method of the water-heat system of the fuel cell is as follows, according to the temperature value detected by the temperature sensor, it is determined that the fuel cell is in a cold start condition, a normal warm-up condition or a high heat dissipation condition; wherein, the temperature sensor can be one of the first to third temperature sensors T30, T32, T33, or a combination of two or three of them.

[0030] If it is in a cold start condition, the heater branch is connected to the liquid circulation loop, and the first heat dissipation branch, the second heat dissipation branch and the intercooler branch are disconnected from the circulation loop; if it is in a normal warm-up condition, the heater branch and the intercooler branch are connected to the liquid circulation loop, and the first heat dissipation branch and the second heat dissipation branch are disconnected from the circulation loop; if it is in a high heat dissipation condition, the first heat dissipation branch, the second heat dissipation branch and the intercooler branch are connected to the liquid circulation loop, and the heater branch is disconnected from the circulation loop.

[0031] In the high heat dissipation working condition, the first heat dissipation branch communicates with the liquid circulation loop with the maximum opening area, and the opening area of the second heat dissipation branch gradually increases.

[0032] The control method further comprises judging whether the fuel cell is in the transition stage working condition from the normal warming-up working condition to the high heat dissipation working condition according to the temperature value detected by the temperature sensor; if in the transition stage working condition, keeping the intercooler branch communicating with the liquid circulation loop, gradually increasing the opening area of the first heat dissipation branch communicating with the liquid circulation loop, and gradually decreasing the opening area of the heater branch communicating with the liquid circulation loop. Further, the control method further comprises gradually increasing the opening area of the second heat dissipation branch communicating with the liquid circulation loop from closed to open if in the transition stage working condition.

[0033] The judgment of the above working conditions is mainly based on the detected temperature, and specifically, the control method comprises presetting a cold start working condition temperature T1, a normal warming-up working condition temperature T2, a transition stage working condition temperature T3 and a high heat dissipation working condition temperature T4, wherein T1 < T2 < T3 < T4; when the temperature value T0 detected by the temperature sensor satisfies T0 < T1, it is judged that the fuel cell is in the cold start working condition; when the temperature value T0 detected by the temperature sensor satisfies T1 < T0 < T2, it is judged that the fuel cell is in the normal warming-up working condition; when the temperature value T0 detected by the temperature sensor satisfies T2 < T0 < T3, it is judged that the fuel cell is in the transition stage working condition; and when the temperature value T0 detected by the temperature sensor satisfies T3 < T0 < T4, it is judged that the fuel cell is in the high heat dissipation working condition.

[0034] The fuel cell further has a shutdown stage working condition, and the control method comprises: if the fuel cell is in the shutdown stage working condition, the first heat dissipation branch, the second heat dissipation branch and the intercooler branch communicate with the liquid circulation loop, and the heater branch and the bypass branch are in a disconnected state with the circulation loop.

[0035] The specific operation process of the fuel cell system will be described below Figure 1 The specific operation process of the fuel cell system will be described below

[0036] When the temperature detected by the interval temperature sensor is less than 2℃, it is judged that the fuel cell is in the cold start working condition, at this time, the f port and the a port of the three-way valve are controlled to be opened, the b port of the three-way valve and the g port, the c port, the d port and the e port of the four-way valve are kept closed, at this time, the liquid circulation loop is composed of the water pump, the stack, the three-way valve and the heater, so as to perform cold start heating on the stack.

[0037] When the temperature detected by the interval temperature sensor is greater than 2°C and less than 50°C, it is determined that the fuel cell is in a normal warm-up condition, at which time the f port and the a port of the three-way valve and the g port, the c port and the e port of the four-way valve are controlled to be open, the b port of the three-way valve and the d port of the four-way valve are controlled to be closed, at which time the liquid circulation loop includes a loop formed by the water pump, the stack, the three-way valve and the heater, a loop formed by the water pump, the stack, the three-way valve and the first radiator, a loop formed by the water pump, the stack, the four-way valve and the bypass path, and a loop formed by the water pump, the intercooler and the deionizer, the four-way valve and the bypass path, so as to normally warm up the stack.

[0038] When the temperature detected by the interval temperature sensor is greater than 50°C and less than a target water temperature (e.g., 80°C), it is determined that the fuel cell is in a transition stage condition, which can be divided into a pre-transition stage and a post-transition stage. In the pre-transition stage, for example, when the temperature is greater than 50°C and less than 55°C, the f port, the a port and the b port of the three-way valve are controlled to be open, the b port is controlled to have a small opening degree, the g port, the c port and the e port of the four-way valve are controlled to be open, and the d port of the four-way valve is controlled to be closed, at which time the liquid circulation loop includes a loop formed by the water pump, the stack, the three-way valve and the heater, a loop formed by the water pump, the stack, the three-way valve and the first radiator, a loop formed by the water pump, the stack, the four-way valve and the bypass path, and a loop formed by the water pump, the intercooler and the deionizer, the four-way valve and the bypass path. In the post-transition stage, at which time there is a low heat dissipation requirement, the f port, the a port and the b port of the three-way valve are controlled to be open, the g port, the c port, the d port and the e port of the four-way valve are controlled to be open, and the d port is controlled to have a small opening degree, at which time the liquid circulation loop includes a loop formed by the water pump, the stack, the three-way valve and the heater, a loop formed by the water pump, the stack, the three-way valve and the first radiator, a loop formed by the water pump, the stack, the four-way valve and the bypass path, a loop formed by the water pump, the intercooler and the deionizer, the four-way valve and the bypass path and / or the second radiator, and a loop formed by the water pump, the stack, the four-way valve and the second radiator.

[0039] When the fuel cell has a high heat dissipation requirement, for example, when the temperature is close to the target water temperature, the a port of the three-way valve is controlled to be closed, the f port and the b port of the three-way valve are controlled to be open, the g port, the c port, the d port and the e port of the four-way valve are controlled to be open, at which time the liquid circulation loop includes a loop formed by the water pump, the stack, the three-way valve and the first radiator, a loop formed by the water pump, the stack, the four-way valve and the bypass path, a loop formed by the water pump, the intercooler and the deionizer, the four-way valve and the bypass path, and a loop formed by the water pump, the stack, the four-way valve and the second radiator.

[0040] When the fuel cell is shut down, to prevent the temperature of the stack from being too high, the a port of the three-way valve is controlled to be closed, the f port and the b port of the three-way valve are controlled to be opened, the g port, the c port and the d port of the four-way valve are controlled to be opened, the e port of the four-way valve is controlled to be closed, at this time, the liquid circulation loop includes a loop formed by the water pump, the stack, the three-way valve and the first radiator, a loop formed by the water pump, the intercooler and the deionizer, the four-way valve and the second radiator, and a loop formed by the water pump, the stack, the four-way valve and the second radiator.

[0041] It should be noted that the above various working conditions are divided according to the approximate running working conditions of the fuel cell from starting to normal running and then to shutdown, the division of each working condition is not mutually exclusive, the control logic between adjacent working conditions is smoothly transitioned, and there can be overlap between adjacent working conditions.

[0042] It can be known from the above description that the water and heat system of the fuel cell provided by the application is provided with two radiators, and the first radiator, the second radiator, the heater and the bypass are connected in parallel in the water and heat system formed by the three-way valve and the four-way valve, which can meet the running modes of cold start warm-up, normal warm-up, transition stage, low heat dissipation requirement, high heat dissipation requirement and other working conditions, so as to meet the temperature regulation requirements under various working conditions.

[0043] The application is described by several specific embodiments, and those skilled in the art should understand that various transformations and equivalent substitutions can be made to the application without departing from the scope of the application. In addition, various modifications can be made to the application for specific situations or specific conditions without departing from the scope of the application. Therefore, the application is not limited to the disclosed specific embodiments, but should include all the embodiments falling within the scope of the claims of the application.

Claims

1. A hydrothermal system of a fuel cell comprising a liquid circulation loop that passes through an electric pile of the fuel cell to adjust the temperature of the electric pile, characterized by, The liquid circulation loop is connected with a water pump, a first radiator, a second radiator, a heater, an intercooler, a three-way valve and a four-way valve, the first radiator, the second radiator and the heater are connected in parallel to the liquid circulation loop, the liquid circulation loop further comprises a bypass connected in parallel to the first radiator, the second radiator and the heater, the three-way valve comprises one inlet end and two outlet ends, the four-way valve comprises two inlet ends and two outlet ends, the inlet end of the three-way valve and one inlet end of the four-way valve are respectively connected to the outlet of the liquid circulation loop after the electric pile, the other inlet end of the four-way valve is connected to the intercooler, and the four outlet ends formed by the three-way valve and the four-way valve are respectively connected to the first radiator, the second radiator, the heater and the bypass. The heat dissipation capacity of the first radiator is greater than that of the second radiator, the first radiator and the heater are respectively connected to the two outlet ends of the three-way valve, the second radiator and the bypass are respectively connected to the two outlet ends of the four-way valve, the on-off and opening size of the two outlet ends of the three-way valve are associated with adjustable control, the on-off and opening size of the two outlet ends of the four-way valve are associated with adjustable control, and the on-off and opening degree relationship between the three-way valve and the four-way valve is independently adjustable control.

2. The water thermal system of a fuel cell as claimed in claim 1, wherein The three-way valve is an electronic throttle valve.

3. The water thermal system of a fuel cell as claimed in claim 2, wherein The first radiator is a front-mounted radiator, and the second radiator is a side-mounted radiator.

4. The water thermal system of a fuel cell as claimed in claim 1, wherein The liquid circulation loop further comprises a deionizer connected in parallel to the intercooler, and the inlet ends of the intercooler and the deionizer are connected to the inlet of the liquid circulation loop before the electric pile, and the outlet ends of the intercooler and the deionizer are connected to one inlet end of the four-way valve.

5. The water thermal system of a fuel cell as claimed in claim 1, wherein The four-way valve comprises a single valve component with four ports, or a single valve component with more than four ports, and four ports connected to the liquid circulation loop, or a combined valve component formed by connecting two three-way valves.

6. The water thermal system of a fuel cell as claimed in any one of claims 1 to 5, wherein The liquid circulation loop is provided with first to third temperature sensors, the first temperature sensor is connected to the outlet after the first radiator and the second radiator are connected in parallel, the second temperature sensor is connected to the inlet of the liquid circulation loop before the electric pile, and the third temperature sensor is connected to the outlet of the liquid circulation loop after the electric pile.

7. The water thermal system of a fuel cell as claimed in claim 1, wherein The water heating system further comprises a waste heat utilization branch, and the front end of the waste heat utilization branch is connected to the outlet of the liquid circulation loop after the electric pile, and the rear end is connected to the water pump.

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