CN2852224Y

CN2852224Y - Heat radiation control circuit of fuel cell engine

Info

Publication number: CN2852224Y
Application number: CNU2005200473092U
Authority: CN
Inventors: 付明竹; 鲍军辉; 郭磊; 胡里清
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2005-12-08
Filing date: 2005-12-08
Publication date: 2006-12-27
Anticipated expiration: 2015-12-08

Abstract

The utility model relates to a heat radiation control circuit of fuel cell engines, which comprises a monolithic computer U1 for control signal output, a photoelectric coupler U2 for control signal amplification, a field effect tube V1, a temperature sensor U3 for temperature acquisition of a radiator fan M1 and a CAN bus interface circuit U4 for control command acceptance, wherein the radiator fan M1 is driven by the field effect tube V1 in the heat radiation control circuit, the monolithic computer U1 is connected to the input end of the field effect tube V1 through the photoelectric coupler U2 in the heat radiation control circuit, the radiator fan M1 is connected to and driven by the output end of the field effect tube V1, and the monolithic computer U1 is respectively connected with the temperature sensor U3 and the CAN bus interface circuit U4. The utility model has the characteristics of small size, light weight, fast switching speed, good high frequency characteristic, superior heat stability, etc. In addition, the radiator fan adopts stepless speed change to avoid temperature fluctuation impact exerted to fuel cells.

Description

Fuel cell engine heat dissipation control circuit

Technical Field

The utility model relates to a fuel cell especially relates to a fuel cell engine heat dissipation control circuit.

Background

A fuel cell is a device that can convert chemical energy generated when a fuel and an oxidant electrochemically react into electrical energy. The core component of the device is a Membrane Electrode (MEA), which consists of a proton exchange Membrane and two conductive porous diffusion materials (such as carbon paper) sandwiched between two surfaces of the Membrane, and finely dispersed catalysts (such as platinum) capable of initiating electrochemical reaction are uniformly distributed on the two side interfaces of the proton exchange Membrane contacting with the conductive materials. The electrons generated in the electrochemical reaction process are led out by conductive objects at two sides of the membrane electrode through an external circuit, thus forming a current loop.

At the anode end of the membrane electrode, fuel can permeate through a porous diffusion material (such as carbon paper) and undergo electrochemical reaction on the surface of a catalyst, electrons are lost to form positive ions, and the positive ions can pass through a proton exchange membrane through migration to reach the other end-cathode end of the membrane electrode. At the cathode end of the membrane electrode, a gas (e.g., air) containing an oxidant (e.g., oxygen) permeates through a porous diffusion material (e.g., carbon paper) and electrochemically reacts at the surface of the catalyst to give electrons that form negative ions that further combine with positive ions migrating from the anode end to form a reaction product.

In a proton exchange membrane fuel cell using hydrogen as fuel and air containing oxygen as oxidant (or pure oxygen as oxidant), the fuel hydrogen undergoes a catalytic electrochemical reaction in the anode region without electrons to form hydrogen positive ions (protons), and the electrochemical reaction equation is as follows: (ii) a Catalytic electrochemical reaction of oxygen in cathode region to obtain electronsAnd becomes negative ions which further combine with the positive hydrogen ions migrating from the anode side to form water as a reaction product. The electrochemical reaction equation is as follows: 。

the function of the proton exchange membrane in a fuel cell, in addition to serving to carry out the electrochemical reaction and to transport the protons produced in the exchange reaction, is to separate the gas flow containing the fuel hydrogen from the gas flow containing the oxidant (oxygen) so that they do not mix with each other and produce an explosive reaction.

In a typical pem fuel cell, the membrane electrode is generally placed between two conductive plates, and the two plates are both provided with channels, so the membrane electrode is also called as a current-guiding plate. The diversion grooves are arranged on the surface contacted with the membrane electrode and formed by die casting,stamping or mechanical milling and carving, and the number of the diversion grooves is more than one. The flow guide polar plate can be made of metal materials or graphite materials. The diversion trench on the diversion polar plate is used for respectively guiding fuel or oxidant into the anode region or the cathode region at two sides of the membrane electrode. In the structure of a single proton exchange membrane fuel cell, only one membrane electrode and two flow guide polar plates are arranged on two sides of the membrane electrode, one is used as the flow guide polar plate of anode fuel, and the other is used as the flow guide polar plate of cathode oxidant. The two flow guide polar plates are used as current collecting plates and mechanical supports at two sides of the membrane electrode. The diversion trench on the diversion polar plate is a channel for fuel or oxidant to enter the surface of the anode or the cathode, and is a water outlet channel for taking away water generated in the operation process of the battery.

In order to increase the power of the pem fuel cell, two or more single cells are connected together in a stacked or tiled manner to form a stack, or referred to as a cell stack. Such a battery pack is generally fastened together into one body by a front end plate, a rear end plate, and tie rods. In the battery pack, flow guide grooves, called bipolar plates, are arranged on both sides of a polar plate positioned between two proton exchange membranes. One side of the bipolar plate is used as an anode diversion surface of one membrane electrode, and the other side is used as a cathode diversion surface of the other adjacent membrane electrode. A typical battery pack also generally includes: 1) inlet and flow guide channels for fuel and oxidant gases. The fuel (such as hydrogen, methanol or hydrogen-rich gas obtained by reforming methanol, natural gas and gasoline) and oxidant (mainly oxygen or air) are uniformly distributed in the diversion trenches of the anode and cathode surfaces; 2) an inlet and an outlet for cooling fluid (such as water) and a flow guide channel. The cooling fluid is uniformly distributed in the cooling channels in each battery pack to absorb the reaction heat generated in the fuel cell and carry the reaction heat out of the battery pack for heat dissipation; 3) the outlets of the fuel and oxidant gases and the flow guide channel. The function of the device is to discharge the excessive fuel gas and oxidant which do not participate in the reaction, and simultaneously carry out the liquid or gaseous water generated by the reaction. The fuel inlet/outlet, the oxidant inlet/outlet, and the cooling fluid inlet/outlet are typically provided on one end plate or on both end plates of the fuel cell stack.

The proton exchange membrane fuel cell can be used as a power system of vehicles, ships and other vehicles and can also be manufactured into a movable or fixed power generation system.

In a fuel cell power generation system, conventional fuel cell engine cooling drives the start and stop of a cooling fan by closing and opening a relay contact. The control method has the advantages that the circuit board is large in size, the relay contacts are frequently contacted, the contacts are easy to oxidize to cause poor contact, the relay contacts are easy to generate sparks in the contact process, if hydrogen leaks, explosion can be caused, and the temperature of the engine water of the fuel cell controlled by the method is unstable and fluctuates.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to a heat dissipation control circuit for a fuel cell engine, which overcomes the above-mentioned drawbacks of the prior art.

The purpose of the utility model is realized like this: a heat dissipation control circuit of a fuel cell engine is characterized by comprising a single chip microcomputer U1 for outputting control signals, a photoelectric coupler U2 for amplifying the control signals, a field effect transistor V1, a temperature sensor U3 for acquiring the temperature of a heat dissipation fan M1 and a CAN bus interface circuit U4 for receiving control commands, wherein the circuit adopts a field effect transistor V1 to drive the heat dissipation fan M1, the single chip microcomputer U1 is connected with the input end of the field effect transistor V1 through the photoelectric coupler U2, the output end of the field effect transistor V1 is connected with and drives the heat dissipation fan M1, and the single chip microcomputer U1 is respectively connected with the temperature sensor U3 and the CAN bus interface circuit U4.

The control signal output by the singlechip U1 is a PWM (pulse width modulation) signal.

The field effect transistor V1 is a high-power MOSFET field effect transistor, and directly controls the current of the motor of the cooling fan M1 and realizes stepless speed regulation.

The motor of the heat radiation fan M1 obtains pulsating current.

The running speed of the motor of the cooling fan M1 CAN be controlled by commands from other command controllers on a CAN bus, and CAN also be directly controlled by a temperature sensor U3.

The chip of the single chip microcomputer (U1) adopts LPC2119ARM, and the chip is provided with a PWM pulse width modulation output signal.

The photoelectric coupler (U2) adopts a PC 817.

The utility model discloses owing to adopted above technical scheme, overcome prior art's defect. Compared with the prior art, the utility model discloses fuel cell engine heat dissipation controlling means adopts high-power field effect transistor drive radiator fan, and is small, light in weight, and switching speed is fast, high frequency characteristic is good, thermal stability is good, and main circuit work is at on-off state, and the conduction loss is little, and the device is efficient, and radiator fan infinitely variable avoids bringing the temperature fluctuation for fuel cell and assaults.

Drawings

Fig. 1 is a block diagram of a fuel cell engine heat dissipation control circuit of the present invention;

fig. 2 is a heat dissipation control circuit diagram of the fuel cell engine of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

Referring to fig. 2, fig. 2 is an embodiment of heat dissipation control in a 50kw fuel cell engine of the present invention. The single chip microcomputer U1 receives running speed signals of a motor of the cooling fan sent by other command controllers on a CAN bus through a CAN bus interface circuit U2, a PWM pulse width modulation signal is output to a photoelectric coupler U2 from a POT1 port, a transistor at the output end of the photoelectric coupler U2 transmits a pair of transistors of a collector to be grounded GND1, the pair of transistors of the collector to be grounded is connected with two branches, one branch is connected with a power supply +12V through a resistor R3, the other branch is connected with a grid electrode of a field effect tube V1, the source electrode of the field effect tube V1 is grounded, a resistor R2 is connected between the grid electrode and the source electrode, the drain electrode of the field effect tube V1 is connected with the negative electrode of a cooling fan motor M1, and. The diode V2 is connected in parallel at two ends of the cooling fan motor M1, the cathode of the diode V2 is connected with the power supply VCC, and the anode is connected with the drain of the field effect tube V1.

The singlechip U1 adopts LPC2119ARM with PWM pulse width modulation output signal, and the photoelectric coupler U2 adopts PC 817. The singlechip chip U1 drives the high-power field effect transistor V1 in an isolated way through the photoelectric coupler U2, and the field effect transistor V1 directly controls the current of a motor M1 of a heat radiation fan of a 50kw fuel cell engine so as to achieve the purpose of speed regulation. The operation speed of the motor of the cooling fan in the embodiment is operated by receiving commands of other command controllers on the CAN bus, and the temperature collector CAN be additionally arranged to directly control the temperature.

Claims

1. The fuel cell engine heat dissipation control circuit is characterized by comprising a single chip microcomputer (U1) for outputting control signals, a photoelectric coupler (U2) for amplifying the control signals, a field effect transistor (V1), a temperature sensor (U3) for collecting the temperature of a heat dissipation fan (M1), and a CAN bus interface circuit (U4) for receiving control commands, wherein the circuit adopts the field effect transistor (V1) to drive the heat dissipation fan (M1), the single chip microcomputer (U1) in the circuit is connected with the input end of the field effect transistor (V1) through the photoelectric coupler (U2), the output end of the field effect transistor (V1) is connected with the heat dissipation fan (M1), and the single chip microcomputer (U1) is connected with the temperature sensor (U3) and the CAN bus interface circuit (U4) respectively.

2. The fuel cell engine heat dissipation control circuit as recited in claim 1, wherein the control signal output by the single-chip microcomputer (U1) is a PWM pulse width modulation signal.

3. The fuel cell engine heat dissipation control circuit of claim 1, wherein the fet (V1) is a high power MOSFET fet that directly controls the current of the motor of the cooling fan (M1) and achieves stepless speed regulation.

4. The fuel cell engine heat dissipation control circuit as recited in claim 1, wherein the motor of the heat dissipation fan (M1) draws a pulsating current.

5. The fuel cell engine emissions control circuit of claim 1, wherein the operating speed of the motor of the radiator fan (M1) is controlled by commands from other command controllers on the CAN bus, or directly by a temperature sensor (U3).

6. The fuel cell engine heat rejection control circuit as set forth in claim 1 wherein said single chip microcomputer (U1) chip utilizes LPC2119ARM with PWM pulse width modulated output signal.

7. The fuel cell engine heat dissipation control circuit of claim 1, wherein the opto-coupler (U2) is PC 817.