Hydrogen circulating pump and fuel cell system
By using inverter heating and heating components in the hydrogen circulation pump to directly heat the impeller freezing in low-temperature environments, the rapid start of the hydrogen circulation pump is achieved, and the stable operation of the fuel cell system under low temperature conditions is ensured.
Patent Information
- Application Number
- CN202421102143.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-05-20
AI Technical Summary
In a low temperature environment, the impeller of the hydrogen circulation pump is prone to freeze, resulting in failure in starting, and the prior art is difficult to start stably under low temperature conditions.
By introducing an inverter into a hydrogen circulation pump, an alternating current of a certain frequency and amplitude is applied to generate heat and break ice, and a heating assembly is installed on the pump head, direct heating is performed using a resistive heating element or a Peltier heating element. Ensure that the pump head and impeller can start quickly at low temperatures.
The rapid and safe start of the hydrogen circulation pump in a low-temperature environment is achieved, which avoids startup failures caused by freezing and ensures the normal operation of the fuel cell system.
Smart Images
Figure CN222228900U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to fuel cell technology, and in particular to a hydrogen circulation pump in a fuel cell system. Background Art
[0002] The hydrogen circulation pump is used to circulate hydrogen at the anode end of the hydrogen fuel cell. Its function is to pressurize and transport the unreacted hydrogen at the outlet of the fuel cell stack to the inlet of the fuel cell stack for recovery, so as to fully reuse the hydrogen. Usually, the hydrogen circulation pump has a motor and a pump head. The motor is associated with the impeller in the pump head through the motor shaft, so that the rotation of the motor shaft drives the impeller to rotate, thereby circulating the hydrogen.
[0003] However, in the current fuel cell engine's anode loop, liquid water is an unavoidable medium based on the fuel cell reaction process. Thus, when the vehicle is in a low-temperature environment, especially after the engine is shut down in winter, for example, when the ambient test temperature is below 0°C, the impeller in the pump head of the hydrogen circulation pump may be frozen, resulting in the failure of the hydrogen circulation pump to start.
[0004] Therefore, it is necessary to provide a hydrogen circulation pump that can be stably started even in a low temperature environment. Utility Model Content
[0005] The present application aims to provide a hydrogen circulation pump that can be stably started even in a low temperature environment.
[0006] To achieve the above-mentioned purpose, the present application provides a hydrogen circulation pump for use in a fuel cell system, comprising: a motor having a stator and a rotor rotatable relative to the stator and a motor shaft associated with the rotor, wherein the rotation of the rotor drives the motor shaft to rotate when power is supplied; and a pump head connected to the motor, wherein the pump head has a pump housing defining a pump chamber, wherein a rotating component is accommodated in the pump chamber, wherein a rotating shaft of the rotating component is associated with the motor shaft, wherein the rotation of the motor shaft drives the rotating shaft of the rotating component to rotate, thereby transporting hydrogen from a pump inlet to a pump outlet, wherein the hydrogen circulation pump further comprises a heating assembly mounted on the pump head; and an inverter electrically connected to the motor to apply an alternating current having a certain frequency and amplitude to the motor, wherein the inverter has a controller for controlling the frequency and amplitude.
[0007] Optionally, the heating assembly comprises a heater and an electrical connection for providing electrical power to the heater.
[0008] Optionally, the heater is a resistance heating element, and the electrical connector is electrically connected to the inverter, and the inverter controls the heating power of the resistance heating element.
[0009] Optionally, the heater is a Peltier heating element, and the electrical connector is electrically connected to the inverter, and the inverter controls the heating power of the Peltier heating element.
[0010] Optionally, a switch for selectively connecting and disconnecting the heating component is provided between the electrical connector of the heating component and the inverter.
[0011] Optionally, the heating component is a heating element that contains a heated medium.
[0012] Optionally, the heating component is a heat exchanger in a heat exchange system.
[0013] Optionally, the pump housing of the pump head has a double-wall structure, and the heatable medium is accommodated in a gap between double walls of the double-wall structure.
[0014] Optionally, the hydrogen circulation pump further comprises a temperature detection device disposed on the pump head, and the controller controls the frequency and amplitude of the alternating current applied to the motor by the inverter based on the ambient temperature and the temperature at the pump head detected by the temperature detection device.
[0015] The present application also relates to a fuel cell system, which includes the hydrogen circulation pump as described above.
[0016] According to the present application, when the hydrogen circulation pump of the fuel cell system is frozen, an inverter is used to continuously apply an alternating current of a certain frequency and amplitude to the motor of the hydrogen circulation pump, so that the stator and the rotor are heated, and the heat is transferred to the pump head housing and the impeller to melt the ice. Moreover, as the rotor vibrates, the ice will be broken and the melting will be accelerated. On the other hand, when necessary, the inverter can be switched to simultaneously power and control the heater provided on the pump head to directly heat the pump head, thereby ensuring that the hydrogen circulation pump can be started quickly and safely even in a low temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other aspects of the present application will be more clearly understood in conjunction with the accompanying drawings. It should be noted that the drawings are only schematic and are not drawn to scale. In the drawings:
[0018] Figure 1 Schematically shows a side view of a hydrogen circulation pump according to the present application;
[0019] Figure 2 Schematically shows an end view of a hydrogen circulation pump according to the present application as viewed from the pump head;
[0020] Figure 3 A side view of a hydrogen circulation pump according to the present application is schematically shown, wherein the motor and the heating assembly are both connected to an inverter;
[0021] Figure 4 shows a waveform diagram of the AC current applied to the motor of the hydrogen circulation pump;
[0022] Figure 5 A magnetic field diagram showing the stator and rotor in the motor of the hydrogen circulation pump when an alternating current is applied;
[0023] Figure 6 A diagram showing the alternating torque generated by the stator and rotor in the motor of the hydrogen circulation pump when an alternating current is applied. DETAILED DESCRIPTION
[0024] The preferred embodiments of the present application are described in detail below in conjunction with examples. It should be understood by those skilled in the art that these embodiments are not intended to limit the present application in any way, and the features in the various embodiments may be combined with each other. In different drawings, the same components are represented by the same reference numerals, and for the sake of brevity, some components are omitted, but this does not mean that other components are excluded. It should be understood that the size, proportional relationship and number of components of the various components in the drawings are not intended to limit the present application.
[0025] As mentioned above, liquid water is an unavoidable medium in the anode path of current fuel cell engines. Therefore, after the engine is shut down in a low temperature environment, for example, when the ambient test temperature is below 0°C, the impeller of the hydrogen circulation pump may be frozen, resulting in failure to start the hydrogen circulation pump. To this end, the embodiments of the present application are all based on how to heat up or de-ice the impeller of the hydrogen circulation pump.
[0026] In the following description of the present application, the hydrogen circulation pump will be described by taking an impeller pump as an example. However, the hydrogen circulation pump of the present application is not limited to this, and may also be other types of pumps, such as gear pumps, Roots pumps, and other various positive displacement pumps that transport gaseous media based on changes in the volume of the pump chamber. The objects to be heated will also be the pump housing and the rotating shaft and rotating parts inside the housing, namely the pump rotor, such as gears and Roots rotors.
[0027] Figure 1A hydrogen circulation pump 100 for a fuel cell system according to the present application is shown, the hydrogen circulation pump 100 includes a motor 1 for providing a rotational torque for a rotating member of the hydrogen circulation pump, such as an impeller, the motor 1 having a stator, a rotor rotatable relative to the stator, and a motor shaft (not shown in the figure) rotating with the rotor, the hydrogen circulation pump 100 also includes a pump head 2 associated with the motor 1, the pump head 2 includes a pump housing 21 defining a pump cavity and an impeller (not shown in the figure) accommodated in the pump housing 21, the shaft of the impeller and the motor shaft can be used as an integral shaft, or the motor shaft and the impeller shaft can be coupled by a coupling, so that the rotation of the motor shaft is transmitted to the impeller shaft, and the impeller in the pump head 2 is driven to rotate by the motor 1, and then hydrogen is transported from the hydrogen inlet 22 of the pump head 2 to the hydrogen outlet 23, completing the hydrogen transportation process. In the accompanying drawings, the internal structures of the motor 1 and the pump head 2 are not shown, and they can be conventional structures in hydrogen circulation pumps known in the art, and are not described in detail here.
[0028] Figure 2 FIG. 2 shows an end view of the hydrogen circulation pump 100 in the present application as viewed from the pump head 2. The pump head 2 has a pump housing 21, and an end cover 24 is provided on the pump housing 21. Figure 2 The end cap 24 is shown as a circular end cap 24, which can be detachably attached to the pump housing 21 to cover the pump chamber. A heating assembly 25 is arranged on the end cap 24, and the heating assembly 25 includes a heater 27 and an electrical connection 26 connected to the heater 27 to supply power to the heater 27.
[0029] The heater 27 may be a Peltier heater, which may be bonded to the end cap 24 by a thermally conductive adhesive.
[0030] Alternatively, the heater 27 may be an electric heating element, for example comprising a resistance coil, which may be fixed to the end cap 27 by a mechanical connection such as welding or threading.
[0031] The heater 27 in the figure is circular, but can be set to other shapes as needed, such as rectangular, etc., which can be compatible with the shape of the pump housing 21.
[0032] Optionally, the heating component 25 may also be a heat exchange element in a cooling / heating circuit including a medium, which transfers heat to the end cover 24 through the flow of the heated medium.
[0033] Although Figure 2 What is shown is that the heater 27 is attached to the end surface of the end cover 24, but the present application is not limited to this. Instead, it can be set at other positions of the pump housing 21 of the pump head 2, for example, or a heating coil can be wound around the entire pump housing 21 to heat the entire pump head 2.
[0034] In addition, a part or the whole of the pump housing 21 may be configured as a double-wall structure, wherein the gap between the double walls can be used for the circulation of the heated medium to heat the pump head 2 .
[0035] Figure 3 2 shows a hydrogen circulation pump 100 according to the present application connected to an inverter 3 .
[0036] The inverter 3 has an electrical connector 32 , the motor 1 of the hydrogen circulation pump 100 has a controller 11 , and the controller 11 also has an electrical connector 12 . The electrical connector 12 of the motor 1 is electrically connected to the electrical connector 32 of the inverter 3 via a cable 31 .
[0037] The electrical connector 26 of the heating component 25 can also be electrically connected to a cable 31 arranged between the motor 1 and the inverter 3 through a cable 28, and a switch 29 is arranged therebetween to control the power supply and power off of the heater 27, and the heating power of the heater 27 can also be adjusted through the inverter 3, thereby adjusting the temperature of the pump head 2.
[0038] Of course, the cable 28 may also be directly connected to the electrical connector 32 of the inverter 3 and the control unit of the inverter 3 .
[0039] Various types of temperature sensors may also be provided on the pump head 2 to detect the temperature of the pump head 2 , thereby controlling the opening of the switch 29 and adjusting the heating power of the heater 27 or controlling the heating time thereof based on the temperature of the pump head 2 .
[0040] The following describes in detail the process of heating and deicing the pump head 2 of the hydrogen circulation pump by the heating component 5 of the inverter 3.
[0041] like Figure 3 As shown, the inverter 3 can apply an alternating current of a certain frequency and amplitude to the motor 1 of the hydrogen circulation pump through the cable 31, for example, Figure 4 The AC current of the frequency and amplitude shown in can be applied to the motor 1, and the frequency and amplitude can be set specifically as needed. In this way, when the vehicle is in a low temperature environment and the impeller in the pump head 2 of the hydrogen circulation pump is frozen, the AC current is continuously applied to the motor 1 through the inverter 3, and the stator and rotor of the motor 1 will be as follows under the action of the AC current. Figure 5 As shown in the figure, a rotating stator magnetic field is formed, so that the stator of the motor forms a magnetic field on the rotor as shown in the figure. Figure 6 The alternating torque shown in the figure, the process of continuously applying alternating current will produce two effects.
[0042] On the one hand, under the action of alternating current, the stator and rotor of the electron will heat up. For example, the heating process of the stator is as follows:
[0043] Copper loss: P cu =I 2 R, where I is the effective value of the AC battery and R is the line resistance
[0044] Iron loss: P Fe =σ h f 2 +σ e (fB) 2
[0045] And the heating process of the rotor is as follows:
[0046] Iron loss: P Fe =σ h f 2 +σ e (fB) 2
[0047] where σ h and σ e Iron loss coefficient
[0048] The heat generated by the stator and the rotor will be transferred along the motor shaft from the stator and the rotor to the impeller shaft and then to the impeller. In addition, the heat will be directly conducted from the motor housing 1 to the pump housing 21 of the pump head 2. Under such heat transfer, the impeller inside the pump head 2 and the pump housing 21 will be heated, so that the frozen part will slowly melt.
[0049] On the other hand, since the stator of the motor forms a Figure 6 The alternating torque shown causes the rotor to vibrate, thereby driving the motor shaft and the impeller shaft to vibrate, and ultimately breaking the ice on the frozen part.
[0050] Therefore, under the dual effects of heat transfer and ice-breaking effect caused by vibration, the ice inside the pump head 2 can be melted quickly.
[0051] In addition, the inverter 3 can control and adjust the size and duration of the AC battery applied to the motor 1 as needed. For example, the frequency and amplitude of the AC current and the duration of the current application can be controlled based on the detection value of the temperature sensor set on the pump head 2.
[0052] On the other hand, in addition to the above process, direct heating of the end cover 24 and the pump housing 21 by the heater 27 will transfer heat to the interior of the pump head 2, thereby quickly heating the impeller and impeller shaft in the pump head 2. This heating process is combined with the action of the inverter 3 on the motor 1 to more quickly achieve the de-icing process of the hydrogen circulation pump.
[0053] The following is a summary of the working process of the present application. When the fuel cell engine is in a low temperature environment, causing the impeller of the hydrogen circulation pump 100 to be frozen, on the one hand, the inverter 3 continuously applies an alternating current of a certain frequency and amplitude to the motor of the hydrogen circulation pump 100, so that the stator and the rotor are heated, and the heat is transferred to the pump head housing and the impeller to melt the ice. Moreover, as the rotor vibrates, the ice will also be broken and the melting will be accelerated. On the other hand, when necessary, the inverter 3 can be switched to simultaneously power and control the heater 27 provided on the pump head 2 to directly heat the pump head 2.
[0054] The application of AC current by the inverter 3 to the motor 1 and the switching on of the heater 27 by the inverter 3 can be performed selectively or simultaneously as needed, depending on the deicing speed required by the hydrogen circulation pump and the ambient temperature of the vehicle.
[0055] The present application has been described in detail above in conjunction with specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and do not constitute a limitation to the present application. For those skilled in the art, various modifications or changes can be made to the present application without departing from the spirit of the present application, and these modifications or changes do not depart from the scope of the present application.
Claims
1. A hydrogen circulation pump for a fuel cell system, characterized in that: include: A motor having a stator and a rotor rotatable relative to the stator and a motor shaft associated with the rotor, wherein the rotation of the rotor drives the motor shaft to rotate when power is supplied; as well as A pump head connected to the motor, the pump head having a pump housing defining a pump chamber, the pump chamber accommodating a rotating component, the rotating shaft of the rotating component being associated with the motor shaft, the rotation of the motor shaft driving the rotating shaft of the rotating component to rotate, and hydrogen is transported from the pump inlet to the pump outlet, The hydrogen circulation pump further comprises a heating component mounted on the pump head; and An inverter is electrically connected to the motor to apply an alternating current with a certain frequency and amplitude to the motor, and the inverter has a controller for controlling the frequency and amplitude.
2. The hydrogen circulation pump according to claim 1, characterized in that: The heating assembly includes a heater and an electrical connection for providing power to the heater.
3. The hydrogen circulation pump according to claim 2, characterized in that: The heater is a resistance heating element, and the electrical connector is electrically connected to the inverter, and the inverter controls the heating power of the resistance heating element.
4. The hydrogen circulation pump according to claim 2, characterized in that: The heater is a Peltier heating element, and the electrical connector is electrically connected to the inverter, and the inverter controls the heating power of the Peltier heating element.
5. The hydrogen circulation pump according to claim 3 or 4, characterized in that: A switching switch for selectively connecting and disconnecting the heating component is provided between the electrical connector of the heating component and the inverter.
6. The hydrogen circulation pump according to claim 1, characterized in that: The heating assembly is a heating element that contains a heated medium.
7. The hydrogen circulation pump according to claim 4, characterized in that: The heating component is a heat exchanger in a heat exchange system.
8. The hydrogen circulation pump according to claim 1, characterized in that: The pump housing of the pump head has a double-wall structure, and a heatable medium is accommodated in a gap between double walls of the double-wall structure.
9. The hydrogen circulation pump according to claim 1, characterized in that: It also includes a temperature detection device disposed on the pump head, and the controller controls the frequency and amplitude of the alternating current applied to the motor by the inverter based on the ambient temperature and the temperature at the pump head detected by the temperature detection device.
10. A fuel cell system, characterized in that: The fuel cell system comprises a hydrogen circulation pump according to any one of claims 1 to 9.