CN106711477A - Cooling circulation process for fuel cell - Google Patents

Abstract

The invention discloses a cooling cycle process for fuel cells, which belongs to the technical field of fuel cell engineering design. The present invention is used for the cooling circulation process of fuel cells, using a first circulation loop and a second circulation loop arranged in parallel, the first circulation loop is provided with a heat source liquid cooling device; the second circulation loop is provided with a heat exchanger heat device. The cooling circulation process for the fuel cell of the present invention is beneficial to recycle the heat energy of the fuel cell, and has high energy conversion efficiency.

Description

A cooling cycle process for fuel cells

technical field

The invention belongs to the technical field of fuel cell engineering design, and in particular relates to a cooling cycle process for fuel cells.

Background technique

With the further development of industrial society, environmental problems have become increasingly prominent, and environmentally friendly hydrogen energy storage technology has received more and more attention. Hydrogen energy storage technology includes the production, storage, transportation and use of hydrogen. The most critical link in its industrial chain is fuel cell technology. Fuel cell technology has entered the initial stage of industrialization under the research of scientific and technical personnel all over the world.

The traditional fuel cell module only includes the fuel cell stack, the cooling medium transmission unit, the hydrogen transmission unit, the air transmission unit, and the fuel cell power control unit. The conversion efficiency is low.

Those skilled in the art have been devoting themselves to finding a process that has a stack heat recovery unit so as to recycle the heat energy of the fuel cell and improve the energy conversion efficiency. For this reason, Chinese patent document CN 101587962A discloses a proton exchange membrane fuel cell cooling system, which system includes a sensing mechanism, a control module, an actuator and a cooling mechanism, wherein the output end of the sensing mechanism is connected with the input end of the control module to Transmitting sensing signals, the output end of the control module is connected to the input end of the actuator, the output end of the actuator is connected to the input end of the cooling mechanism, and the output end of the cooling mechanism is connected to the input end of the sensing mechanism.

The system can transmit the temperature values of the inlet and outlet ports of the coolant to the control module in real time through the setting of the temperature sensor. The control module judges and selects the cooling route according to the real-time data, and controls the opening direction of the three-way valve through the actuator. The system realizes the control of the first-level error fluctuation of the temperature, and the system partially realizes the improvement of the energy conversion efficiency of the fuel cell through the control of the temperature error fluctuation, but it is only analyzed from the perspective of fuel cell temperature control and cannot be analyzed according to the outlet The temperature classification of the cooling liquid selects the cooling circulation loop for energy recovery, and the energy conversion efficiency is not ideal.

Contents of the invention

For this reason, the present invention aims at the technical defect that the fuel cell module of the prior art cannot be selected according to the temperature classification of the outlet coolant of the fuel cell, and the energy conversion efficiency of the cooling cycle loop is not ideal, thereby providing a cooling cycle for the fuel cell craft.

In order to solve the problems of the technologies described above, the technical scheme adopted in the present invention is as follows:

A cooling cycle process for fuel cells, using

It includes a first circulation loop and a second circulation loop arranged in parallel, a heat source liquid cooling device is arranged on the first circulation loop; a heat exchange device is arranged on the second circulation loop.

Proceed as follows:

(1) Make the heat source liquid at the outlet of the fuel cell pass into the cooling circulation loop through the second circulation pump;

(2) Make the heat source liquid output by the cooling circulation loop flow through the second liquid storage tank, and further flow into the fuel cell.

A cooling device is also provided on the second circulation loop.

Also includes,

(1) Setting the first temperature threshold M1,

(2) When the temperature of the coolant flowing out of the fuel cell is lower than M1, the coolant returns to the fuel cell through the first circulation loop;

(3) When the temperature of the coolant flowing out of the fuel cell is greater than M1, the coolant returns to the fuel cell through the second circulation loop.

A second temperature threshold M2 is also set, wherein M1 is smaller than M2;

When the temperature of the coolant flowing out of the fuel cell is between M1 and M2, the coolant is cooled by the heat exchange device and then returned to the fuel cell;

When the temperature of the cooling liquid flowing out of the fuel cell is greater than M2, the cooling liquid returns to the fuel cell after being cooled by the heat exchange device and the heat dissipation device.

A circuit selection device is also included for controlling the coolant flowing out of the fuel cell to enter the first circulation loop or the second circulation loop.

The second circulation loop is also provided with a first liquid storage tank for receiving heat from the heat exchange device.

A first circulation pump is provided between the heat exchange device and the first liquid storage tank.

The heat exchange device is a plate heat exchanger, and a heat source liquid channel is arranged in the heat exchanger, and a cooling circulating liquid channel is arranged on the periphery of the heat source liquid channel, so that the cooling circulating liquid flows into the First heat reservoir.

A second liquid storage tank connected to the fuel cell is also included;

the first circulation loop and the second circulation loop join at the inlet of the second liquid storage tank;

The circuit selection device is connected with the fuel cell through the second circulation pump.

The circuit selection device is a thermostat, and the heat dissipation device is a radiator.

The fuel cell heat source liquid outlet, the first liquid storage tank and the fuel cell heat source liquid inlet are respectively provided with a first temperature sensor, a second temperature sensor, a third temperature sensor, and the first temperature sensor A temperature detection device and a signal transmission device are installed inside to detect the outlet temperature and transmit it to the second circulation pump, thermostat, heat exchanger and radiator.

The fuel cell is selected from proton exchange membrane fuel cell, direct methanol fuel cell, phosphoric acid fuel cell, molten carbonate fuel cell or high temperature solid oxide fuel cell.

The fuel cell in the present invention includes but not limited to one or more combination of proton exchange membrane fuel cell, direct methanol fuel cell, phosphoric acid fuel cell, molten carbonate fuel cell or high temperature solid oxide fuel cell.

Compared with the prior art, the present invention has the following advantages:

1. The cooling circulation process for fuel cells provided by the present invention includes a first circulation loop and a second circulation loop. The first circulation loop has a heat source liquid cooling device for cooling a lower temperature heat source liquid. The second circulation loop The secondary circulation loop has a heat exchange device to cool the heat source liquid with a slightly higher temperature.

2. The second circulation loop used in the fuel cell cooling circulation process provided by the present invention is further provided with a first liquid storage tank for receiving the heat exported by the heat exchange device. The cooling circulation loop process can convert the heat in the output heat source in the fuel cell to achieve the purpose of reuse, and the energy conversion efficiency is high.

3. The first circulation loop described in the cooling circulation process for fuel cells provided by the present invention is equipped with a heat source liquid purification treatment device to cool and treat the cooling circulation liquid when the heat source liquid outlet temperature T1 of the fuel cell is lower than M1, or It is a small amount of cooling circulating fluid, which can realize the rapid start-up of the fuel cell, and during operation, there will be impurities after the heat source liquid circulates for a period of time. The heat source liquid cooling device can purify impurities and cool the heat source liquid. When the heat source liquid is water, this The device is the deionization column.

4. The second circulation loop described in the cooling circulation process for fuel cells provided by the present invention can cool and treat the cooling circulation liquid when the heat source liquid outlet temperature T1 of the fuel cell is higher than M1 and lower than M2 at the same time, or a large amount of cooling circulating fluid. The heat generated by the fuel cell is utilized.

5. The heat exchange device described in the cooling circulation process for fuel cells provided by the present invention is a plate heat exchanger, and a heat source channel is arranged in the heat exchanger, and a cooling circulation liquid channel is arranged on the periphery of the heat source channel , the cooling circulating fluid flows into the second hot cooling fluid tank through the first circulating pump. It is used to cool down the hot liquid in the heat source channel and bring heat into the first liquid storage tank.

6. The heat dissipation device and the heat exchange device set in the second circulation loop described in the cooling cycle process for fuel cells provided by the present invention work together to cool the fuel cell when the heat source liquid outlet temperature T1 is higher than M2 heat source liquid, or a large amount of heat source liquid. It can ensure the maximum utilization of heat energy at the working temperature of the fuel cell.

7. A first circulation pump is provided between the heat exchange device and the second heat coolant tank in the second circulation loop in the cooling circulation process for fuel cells provided by the present invention, for rapid The cooling circulating fluid is pumped into the first reservoir.

8. In the cooling circulation process for fuel cells provided by the present invention, a temperature detection device and a signal transmission device are provided in the temperature sensor T1 to detect the outlet temperature and transmit it to the second circulation pump, thermostat, and heat exchanger And the radiator, so as to realize the control of the cooling cycle of the system.

9. The cooling circulation process for fuel cells provided by the present invention improves the purity of the heat source liquid without affecting the temperature control by setting the heat source liquid cooling device, and prolongs the life of the fuel cell.

10. The cooling circulation process provided by the present invention can ensure the stable operation of the fuel cell, so that the service life of the fuel cell can be increased from 5000h to 10000h-20000h.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

Fig. 1 is the system diagram of the cooling cycle circuit of the present invention;

The reference signs are as follows:

1-thermostat, 2-heat source liquid purification treatment device, 3-heat exchanger, 4-first liquid storage tank, 5-radiator, 6-first circulation pump, 7-second liquid storage tank, 8- The second circulating pump, 9-fuel cell, 10-the first temperature sensor, 11-the second temperature sensor, 12-the third temperature sensor.

detailed description

The present invention will be described below in conjunction with the accompanying drawings. The following examples are provided in order to further understand the present invention better, are not limited to the best implementation mode, and do not limit the content and protection scope of the present invention, anyone under the inspiration of the present invention or use the present invention Any product identical or similar to the present invention obtained by combining features of other prior art falls within the protection scope of the present invention.

If no specific experimental steps or conditions are indicated in the examples, it can be carried out according to the operation or conditions of the conventional experimental steps described in the literature in this field. The reagents or instruments used, whose manufacturers are not indicated, are all commercially available conventional reagent products.

Explanation: In the present invention, the temperature displayed by the first temperature sensor is T1, that is, the outlet temperature of the heat source liquid of the fuel cell, the temperature displayed by the second temperature sensor is T2, and the temperature displayed by the third temperature sensor is T3. And there are two temperature thresholds, M1 and M2 respectively, M1 is the fuel cell low temperature alarm temperature point; M2 is the fuel cell high temperature alarm temperature point.

When the cooling circulation loop for the fuel cell provided by the present invention is in operation,

When T1<M1, the second circulating pump starts and runs at the lowest speed, the first circulating pump does not start, and the circulating heat source liquid enters the first circulating cooling circuit through the thermostat, which can realize the battery heating up as soon as possible and maintain the quality of the heat source liquid ;

When M1<T1≤M2, the heat source liquid passes through the second circulation loop, the radiator does not start, and only heat exchange is performed through the heat exchanger, and the second liquid storage tank is circulated according to the fuel cell heat source liquid inlet temperature T3 and heat exchange The temperature T2 of the heat source liquid adjusts the speed of the second circulation pump and the first circulation pump to ensure that the temperature T3 is within the allowable range of the fuel cell;

When T1>M2, the heat source liquid passes through the second circulation loop to control the temperature of the heat source liquid, and after passing through the heat exchanger of the second circulation loop, the radiator is activated to further force the heat dissipation of the circulating heat source liquid, and according to the fuel cell heat source liquid inlet The temperature T3 and the temperature of the heat source liquid in the second liquid storage tank of the heat exchange cycle regulate the speed of the second circulation pump and the first circulation pump to ensure that the temperature T3 is within the allowable range of the fuel cell.

The specific values of M1 and M2 can be selected according to the actual situation of the fuel cell in the actual process.

The fuel cell in the present invention includes but not limited to one or more combination of proton exchange membrane fuel cell, direct methanol fuel cell, phosphoric acid fuel cell, molten carbonate fuel cell or high temperature solid oxide fuel cell.

Example 1 The stationary proton exchange membrane fuel cell adopting the cooling circulation process of the present invention

This embodiment uses a 10kW water-cooled proton exchange membrane fuel cell stack with 120 single cells.

In this embodiment, the fuel cell low temperature alarm temperature point and the fuel cell high temperature alarm temperature point are 50° C. and 65° C. respectively.

First, the gas line is purged with nitrogen. Then supply hydrogen and air to the poles of the fuel cell respectively, and start the fuel cell and its auxiliary machines (including the circulation pump). Next, the temperature T1 of the water outlet of the fuel cell, the temperature T2 of the heat exchange circulating water, and the temperature T3 of the water inlet of the fuel cell are detected. When the temperature T1 is lower than 50° C., the second circulation pump is started, and the first circulation pump and the fan of the radiator are not started. When the temperature T1 is higher than 50° C. and lower than 65° C., the first circulation pump is started, but the radiator is not started. As the temperature T1 gradually increases, the speed of the first circulation pump gradually increases. When the temperature T1 is higher than 65°C, start the first circulation pump and start the radiator, and when the temperature T1 is lower than 61°C, turn off the radiator.

Example 2 Direct Methanol Fuel Cell Using the Cooling Circulation Process of the Present Invention

This embodiment uses a 5kW water-cooled direct methanol fuel cell stack with 60 single cells.

First, the gas line is purged with nitrogen. Then supply methanol and air to the two poles of the fuel cell, and start the fuel cell and its auxiliary machines (including the circulation pump). Next, the temperature T1 of the water outlet of the fuel cell, the temperature T2 of the heat exchange circulating water, and the temperature T3 of the water inlet of the fuel cell are detected. When the temperature T1 is lower than 120° C., the second circulation pump and the ion column are started, and the first circulation pump and the fan of the radiator are not started. When the temperature T1 is higher than 120° C. and lower than 135° C., the first circulation pump is activated, but the radiator is not activated. As the temperature T1 gradually increases, the speed of the first circulation pump gradually increases. When the temperature T1 is higher than 135°C, start the first circulation pump and start the radiator, and when the temperature T1 is lower than 130°C, turn off the radiator.

Example 3 High temperature solid oxide fuel cell using the cooling cycle process of the present invention

This embodiment uses a 30kW high temperature solid oxide fuel cell stack with 350 single cells.

First, the gas line is purged with nitrogen. Then supply hydrogen and air to the poles of the fuel cell respectively, and start the fuel cell and its auxiliary machines (including the circulation pump). Next, the temperature T1 of the water outlet of the fuel cell, the temperature T2 of the heat exchange circulating water, and the temperature T3 of the water inlet of the fuel cell are detected. When the temperature T1 is lower than 800° C., the second circulation pump is started, and the first circulation pump and the fan of the radiator are not started. When the temperature T1 is higher than 800° C. and lower than 830° C., the first circulation pump is activated, but the radiator is not activated. As the temperature T1 gradually increases, the speed of the first circulation pump gradually increases. When the temperature T1 is higher than 830°C, start the first circulation pump and start the radiator, and when the temperature T1 is lower than 820°C, turn off the radiator.

test case

Verification of the effect of the fuel cell using the cooling cycle process of the present invention in Examples 1-5

Comparative example 1 is a proton exchange membrane fuel cell using the cooling system disclosed in Chinese patent document CN 101587962A; Comparative example 2 is a common fuel cell in the prior art

Example Stability of operation Battery Life energy conversion rate 1 Stablize 30000 85% 2 Stablize 20000 80% 3 Stablize 15000 98% Comparative example 1 Stablize 8000h 60% Comparative example 2 unstable 5000h 45%

Example 4. Cooling circulation loop for fuel cells

This implementation provides a cooling cycle for fuel cells. As shown in FIG. 1, the cooling cycle for fuel cells 9 provided by the present invention includes a first cycle and a second cycle arranged in parallel, so A heat source liquid cooling device 2 is arranged on the first circulation loop; a heat exchange device is arranged on the second circulation loop. This technical solution can select to start the first circulation loop or the second circulation loop according to the temperature of the heat source liquid output in the fuel cell, and the heat exchange device can convert the heat in the heat source output in the fuel cell to achieve the purpose of reuse, energy High conversion efficiency.

A cooling device is also provided on the second circulation loop. The heat dissipation device and the heat exchange device work together to cool down the heat source liquid when the outlet temperature T1 of the heat source liquid of the fuel cell 9 is higher than M2 , or a large amount of heat source liquid.

The heat source liquid cooling device 2 can cool the cooling circulating fluid when the heat source liquid outlet temperature T1 of the fuel cell is lower than M1, or a small amount of cooling circulating fluid, which can realize the rapid start of the fuel cell; and during operation, the heat source liquid circulates After a period of time, there will be impurities, and the heat source liquid cooling device 2 plays the role of purification again. In the present invention, when the heat source liquid is water, this device is a deionization column.

It also includes a circuit selection device, which is used to control the coolant flowing out of the fuel cell to enter the first circulation loop or the second circulation loop, and the first liquid storage tank 4 is used to receive the heat derived from the heat exchange device, so as to conduct it out for preparation When necessary, the second circulation loop can cool the heat source liquid when the heat source liquid outlet temperature T1 of the fuel cell 9 is higher than M1 and lower than M2 at the same time, or a large amount of heat source liquid.

A first circulating pump 6 is provided between the heat exchange device and the first liquid storage tank, and is used for pumping cooling circulating fluid into the first liquid storage tank 4 rapidly. The heat exchange device is a plate heat exchanger 3, the heat source liquid channel is arranged in the heat exchanger 3, and the cooling circulating liquid channel is arranged on the periphery of the heat source liquid channel, so that the cooling circulating liquid passes through the first circulating pump 6 into the first storage tank 4. It is used to cool down the hot liquid in the heat source liquid channel and bring heat into the first liquid storage tank 4 .

It also includes a second liquid storage tank 7 connected to the fuel cell;

The first circulation loop and the second circulation loop merge at the inlet of the second liquid storage tank 7;

The circuit selection device is connected to the fuel cell 9 through the second circulating pump 8 .

The circuit selection device is a thermostat 1 , and the heat dissipation device is a radiator 5 .

The outlet of the heat source liquid of the fuel cell 9, the inside of the first liquid storage tank 4 and the inlet of the fuel cell heat source liquid are respectively provided with a first temperature sensor 10, a second temperature sensor 11, and a third temperature sensor 12. The first temperature sensor 10 is provided with a temperature detection device and a signal transmission device for detecting the outlet temperature and transmitting it to the second circulating pump 8 , the thermostat 1 , the heat exchanger 3 and the radiator 5 .

The cooling circulation circuit of the fuel cell 9 of the present invention improves the purity of the heat source liquid without affecting the temperature control by adding the heat source liquid cooling device 2 and prolongs the service life of the fuel cell.

In the second circulation loop in this embodiment, most of the circulating heat source liquid passes through the plate heat exchanger 3 and the blast radiator 5 and then returns to the second liquid storage tank 7, that is, most of the circulating heat source liquid passes through nodes 1- Node 4～Node 5～Node 3 reaches the second liquid storage tank 7, and the radiator 5 is activated; a small part of the circulating heat source liquid reaches the second liquid storage tank 7 through Node 1～Node 4～Node 5～Node 3, and the radiator is not activated 5. A very small part of the circulating heat source liquid reaches the second liquid storage tank 7 through nodes 1-node 2-node 3.

The cooling circulation loop of the present invention can increase the service life of the fuel cell 9 from 5000h to 10000h-30000h on the basis of being applied to the fuel cell 9 to ensure the stable operation of the fuel cell 9 .

Apparently the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing The technical solutions described in the embodiments are modified, or equivalent replacements are made to some of the technical features. It is not necessary and impossible to exhaustively list all the implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (12)

1. A cooling cycle process for fuel cells, characterized in that, using It includes a first circulation loop and a second circulation loop arranged in parallel, a heat source liquid cooling device is arranged on the first circulation loop; a heat exchange device is arranged on the second circulation loop. 2. cooling circulation process according to claim 1, is characterized in that, carries out as follows: (1) Make the heat source liquid at the outlet of the fuel cell pass into the cooling circulation loop through the second circulation pump; (2) Make the heat source liquid output by the cooling circulation loop flow through the second liquid storage tank, and further flow into the fuel cell. 3. The cooling circulation process according to claim 2, characterized in that, a cooling device is further arranged on the second circulation loop. 4. cooling cycle process according to claim 3, is characterized in that, also comprises, (1) Setting the first temperature threshold M1, (2) When the temperature of the coolant flowing out of the fuel cell is lower than M1, the coolant returns to the fuel cell through the first circulation loop; (3) When the temperature of the coolant flowing out of the fuel cell is greater than M1, the coolant returns to the fuel cell through the second circulation loop. 5. The method for cooling the fuel cell according to claim 4, characterized in that a second temperature threshold M2 is also set, wherein M1 is smaller than M2; When the temperature of the coolant flowing out of the fuel cell is between M1 and M2, the coolant is cooled by the heat exchange device and then returned to the fuel cell; When the temperature of the cooling liquid flowing out of the fuel cell is greater than M2, the cooling liquid returns to the fuel cell after being cooled by the heat exchange device and the heat dissipation device. 6. The cooling cycle process according to claim 5, further comprising a circuit selection device for controlling the cooling liquid flowing out of the fuel cell into the first circulation loop or the second circulation loop. 7 . The cooling circulation process according to claim 6 , wherein a first liquid storage tank for receiving heat from the heat exchange device is further provided on the second circulation loop. 7 . 8. The cooling circulation process according to claim 7, wherein a first circulation pump is provided between the heat exchange device and the first liquid storage tank. 9. The cooling cycle process according to claim 8, characterized in that, the heat exchange device is a plate heat exchanger, a heat source liquid passage is arranged in the heat exchanger, and a cooling device is arranged around the heat source liquid passage. A circulation fluid channel, so that the cooling circulation fluid flows into the first heat storage tank through the first circulation pump. 10. cooling cycle process according to claim 9, is characterized in that, A second liquid storage tank connected to the fuel cell is also included; the first circulation loop and the second circulation loop join at the inlet of the second liquid storage tank; The circuit selection device is connected with the fuel cell through the second circulation pump. 11. The cooling cycle process according to claim 10, characterized in that, the circuit selection device is a thermostat, and the heat dissipation device is a radiator. 12. The cooling cycle process according to claim 11, characterized in that, at the outlet of the fuel cell heat source liquid, in the first liquid storage tank and at the inlet of the fuel cell heat source liquid, first temperature sensors are correspondingly provided , the second temperature sensor, the third temperature sensor, the first temperature sensor is equipped with a temperature detection device and a signal transmission device for detecting the outlet temperature and transmitting it to the second circulation pump, thermostat, heat exchanger and radiator .