A single battery test fixture with temperature zone setting and a test method thereof

Abstract

The present invention belongs to the field of fuel cell testing technology, and discloses a single cell test fixture with temperature partitioning and a test method thereof, the purpose of which is to measure the current, resistance, air pressure, humidity and other data of each monitoring partition for a conventional partition test board according to the actual characteristics of uneven temperature distribution on the surface of a single cell inside a fuel cell stack, and provide temperature partitioning conditions. The detection partition and the temperature control partition can be the same or different. The present invention provides more in-depth technical support for the development of fuel cells.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel cell testing, and in particular, relates to a single cell fixture with actively controlled temperature partitioning and a testing method thereof. Background Art

[0002] A hydrogen proton exchange membrane fuel cell is formed by stacking multiple single cells, the head and tail single cells are then connected to a current collecting plate, an insulating plate, and an end plate, and are connected into a stack through fixings such as screws or cable ties between the two end plates.

[0003] Under specific stable operating conditions, the total current of each single cell is the same, but the voltage of the single cell at different positions is different, and the efficiency and temperature distribution of each plate are also different.

[0004] For different single cells, their positions in the battery stack affect the average temperature of their single plates. This is particularly serious because the first and last plates are only adjacent to a heating environment on one side, and the other side is the side of the current collector with a lower temperature. As a result, it is common to see that at least one end of the first and last plates is cold, and water vapor condenses to cause water droplets to block the flow channel. In order to reduce the low temperature effect of the first and last plates, it is usually adopted to add plates that do not pass cooling fluid, which can be called fake batteries, or adopt temperature compensation structures on the end plates.

[0005] For a specific single cell, its planar temperature distribution is affected by the flow direction of the cooling fluid, the change in the temperature of the cooling fluid, the change in the reaction intensity and efficiency of the reaction zone, etc., and the temperature at each point on the plane is also different.

[0006] These differences make the temperature distribution of each point on the plane of a fuel cell particularly complex and affect the reaction characteristics of each point, such as the current, voltage, humidity, etc. of the partition detection. The existing plane partition detection of single cells can be divided into a single cell fixture form and a form inserted into the fuel cell stack.

[0007] For example, CN112903790B, CN103245920B, CN109860669B, CN112229537B. These technologies generally do not use a simulated battery stack environment for single-cell testing, that is, they use an environment in which the temperature distribution on both sides of the membrane electrode MEA is only controlled by a single temperature of the fixture, and at most the two sides are independently controlled. When inserted into the battery stack, especially the printed circuit board technology, the interference to the battery stack can be reduced, and the data detected on the voltage, current, temperature, air pressure, humidity, etc. on the specific single-cell plane inside the battery stack, and the contour curves obtained by the simulation technology have well revealed the differences in the plane of the relevant data.

[0008] However, when testing a single battery assembled separately, the existing method of temperature and current partition detection technology usually does not consider the impact of the fixture on temperature mentioned above, where the temperature control of the fixture is often designed and manufactured according to a uniform consideration. Testing under certain conditions, especially due to low voltage and high current, requires a relatively large thickness of the collector plate, and the plate is usually made of metal copper, which has good thermal conductivity and large heat capacity. As a result, the temperature of the position relative to the reaction zone on the plane of the collector plate is more uniform than the temperature of the actual reaction heat generation zone, resulting in a large difference between the actual operating conditions and the apparent test conditions.

[0009] When testing at the stack scale, the thickness of the insert plate is different from that of the conventional plate at least at the manifold position. Therefore, interference introduced by heat transfer cooling and the gas conditions of the single cell entering the stack may lead to different conditions. Due to the complex operating conditions of the stack, it is difficult to repeat specific tests, which is a passive detection. Summary of the invention

[0010] In view of the drawbacks of the prior art, the present invention provides a single-cell test fixture with a temperature partition setting and a test method thereof, which form operating and test conditions that simulate temperature distribution control. The fixture and its cooler establish temperature-corrected and controllable partitions for the single cell, providing a temperature-controllable environment for the partition detector in the detected area.

[0011] In terms of the specifications of the single-cell test, the actual operating characteristics of the uneven temperature distribution inside the battery stack are simulated, and the temperature conditions of the partitions can be set manually to measure the current, resistance, air pressure, humidity and other data of each monitoring partition. The detection partition and the temperature control partition can be the same or different, and the temperature setting also includes unconventional, higher temperatures that exceed the temperature of the reaction zone itself. The present invention provides more in-depth technical support for the development of fuel cells and can effectively solve the technical problems mentioned in the background technology.

[0012] The technical solution adopted by the present invention is as follows:

[0013] A single-cell test fixture with a temperature zoning setting, wherein the fixture has a cooler placement groove on the inner side of the single cell, the cooler is fixed in the fixture through the cooler placement groove, a heat insulation layer is provided on the contact surface between the cooler and the fixture, a zoning detector is provided outside the fixture, the zoning detector is in contact with the single cell to be tested, a coolant inlet main pipe and a coolant outlet main pipe are introduced from the outside of the fixture, a coolant inlet distribution pipe is connected between the fixture and the coolant inlet main pipe, a coolant outlet collection pipe is connected between the fixture and the coolant outlet main pipe, the cooler is provided with two cooler liquid pipe quick plugs serving as coolant inlet and outlet, respectively, which are selected as coolant inlet and outlet ends according to experimental needs, respectively, a coolant inlet end of the cooler liquid pipe quick plug is connected to the coolant inlet distribution pipe, and a coolant outlet end of the cooler liquid pipe quick plug is connected to the coolant outlet collection pipe.

[0014] Furthermore, there are multiple coolant inlet main pipes and multiple coolant outlet main pipes, and there are multiple coolant inlet distribution pipes and multiple coolant outlet collecting pipes.

[0015] Furthermore, multiple coolers can be connected between the coolant inlet distribution pipe and the coolant outlet collection pipe, and the flow of coolant in the fixture can be completed by parallel independent control or return series connection between the multiple coolers, that is, the combined structure between the multiple coolers can be divided into two types: parallel independent control structure and return series structure.

[0016] Furthermore, the parallel independent control structure includes: each cooler is provided with a cooler liquid pipe quick plug at both ends, the cooler liquid pipe quick plug at one end is connected to the coolant inlet distribution pipe, several coolant inlet distribution pipes are connected to the coolant inlet main pipe, the cooler liquid pipe quick plug at the other end is connected to the coolant outlet collection pipe, and the coolant outlet collection pipe is connected to the coolant outlet main pipe.

[0017] Furthermore, the return series structure includes: each cooler is provided with a connecting pipe between coolers at one end, and an independent coolant outlet pipe or an independent coolant inlet pipe is provided at the other end, and the independent coolant outlet pipe and the independent coolant inlet pipe are alternately arranged.

[0018] Furthermore, the cooler placement groove also has a cooler pipe outlet hole perpendicular to the fixture plate surface, and the cooler pipe outlet hole is used for the cooler liquid pipe quick plug to pass through the fixture plate surface, and the cooler liquid pipe quick plug is used to connect the coolant connecting pipe outside the plate surface.

[0019] Furthermore, the cooler is a rectangular heat-conducting metal shell.

[0020] A single-cell testing method with a temperature zoning setting, each cooler is independently controlled or controlled in series. When independently controlled, the coolers sandwiched between the single cell and the fixture have the same temperature condition for the inflow of coolant. The coolant enters from the coolant inlet main pipe, and enters the cooler along each coolant inlet distribution pipe through the cooler liquid pipe quick plug at one end, and then flows into the coolant outlet collection pipe through the cooler liquid pipe quick plug at the other end, and finally flows out through the coolant outlet main pipe. The temperature difference between each coolant inlet distribution pipe and the coolant outlet collection pipe is within 1°C, preferably within 0.5°C, and more preferably within 0.2°C.

[0021] When the series control is adopted, the connecting pipes between the multiple coolers provide the selected series flow between each cooler, wherein the independent coolant inlet main pipe A and the independent coolant outlet main pipe A, the independent coolant inlet main pipe B and the independent coolant outlet main pipe B, the independent coolant inlet main pipe C and the independent coolant outlet main pipe C respectively form a loop, and control the inlet temperature and flow rate of each of them respectively to cause the difference in cooling conditions, and provide the detection partitions with different temperatures, so that the influence test of the local supercooling condensation water blockage and the overheating dry film can be established. The temperature difference between the independent coolant inlet main pipe A and the independent coolant outlet main pipe A, the independent coolant inlet main pipe B and the independent coolant outlet main pipe B, the independent coolant inlet main pipe C and the independent coolant outlet main pipe C is within 1°C, preferably within 0.5°C, and more preferably within 0.2°C.

[0022] The present invention has the following advantages:

[0023] (1) Providing active temperature control operating background support for single-cell testing can easily examine the impact of different temperature distribution characteristics on various performance of the battery stack, so as to optimize and improve the performance of the battery stack, and more conveniently find operating failure conditions caused by uneven temperature distribution or cooling.

[0024] (2) Specifically, by adjusting the local temperature, local condensation and flooding, as well as dry film, are selectively created to study the impact of specific areas and the overall impact. Actual simulations are performed on the simulation results to verify the modified calculation models, which is particularly suitable for the early research and various stages of production research in technology development. It also provides new conditions for theoretical research and obtains corrections to theoretical basic data.

[0025] (3) The test changes are convenient, intuitive, and effective. They can be performed at the single-cell level, with low experimental costs, little influence from interference factors, and good repeatability. In particular, they can provide active changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a top view schematic diagram of a single cell fixture and a temperature-controlled liquid pipeline;

[0027] Figure 2 It is a basic structural diagram of a single cooler;

[0028] Figure 3 It is a schematic diagram of the cooler placement slot structure on the end plate;

[0029] Figure 4 is a side view schematic diagram of the connection between the single cell fixture and the temperature control liquid pipeline;

[0030] Figure 5 It is a schematic diagram of the independent control structure of the parallel cooler in the short direction of the plate;

[0031] Figure 6It is a schematic diagram of the series structure of the short-direction foldback cooler of the plate;

[0032] Figure 7 It is a schematic diagram of the symmetrical connection of the matrix fluid series cooling structure;

[0033] Figure 8 It is a schematic diagram of the asymmetric connection of the matrix fluid series cooling structure.

[0034] Among them, 1. single battery; 2. fixture; 3. coolant inlet main pipe; 4. coolant inlet distribution pipe; 5. coolant outlet collection pipe; 6. coolant outlet main pipe; 7. cooler; 8. cooler liquid pipe quick plug; 9. cooler placement slot; 10. cooler pipe outlet hole; 11. partition detector; 12. independent coolant inlet main pipe A; 13. independent coolant inlet main pipe B; 14. independent coolant inlet main pipe C; 15. independent coolant outlet main pipe A; 16. independent coolant outlet main pipe B; 17. independent coolant outlet main pipe C; 18. multiple connecting pipe groups A connected in series; 19. multiple connecting pipe groups B connected in series; 20. connecting pipes between coolers. DETAILED DESCRIPTION

[0035] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0036] The present invention provides active temperature management conditions, and specific test units, such as temperature, pressure, current and other testing technologies, are known technologies in the art and do not belong to the present invention, so they are not introduced in detail.

[0037] The "coolant" used in the present invention is a conventional general name, referring to a liquid that actually has temperature exchange and stabilization effects, including temperature lowering and temperature raising effects, and does not simply mean cooling an object.

[0038] Example 1

[0039] See also Figures 1 to 4 ,in Figure 1 , Figure 4 This is a basic structural diagram of the present invention. The clamp generally uses a press or bolts to encapsulate the single cell structure, which belongs to conventional known technology. The encapsulation is not described in detail in the figure. The coolant flow control and the inlet and outlet have temperature detection, which are not marked in the figure to simplify the diagram.

[0040] The single cell 1 to be tested is located in the fixture 2, which is a conventional device for fixing the single cell 1 and its partition detector 11. The partition detector 11 is located between the single cell 1 and the cooler 7, and is located on both sides or one side of the single cell 1, that is, the partition detector 11 can be set on one side or on both sides at the same time. The present invention is described according to the simultaneous setting on both sides.

[0041] The cooler 7 is a rectangular heat-conducting metal shell with two cooler liquid pipe quick plugs 8 serving as the inlet and outlet of the coolant. The inner side of the fixture 2 facing the single cell 1 has a cooler placement groove 9 on the fixture, which fixes the cooler 7 in the fixture 2, and the contact surface between the cooler 7 and the fixture 2 has a heat insulation layer. The cooler placement groove 9 also has a cooler pipe through hole 10 perpendicular to the plate surface of the fixture 2, and the cooler pipe through hole 10 is used for the cooler liquid pipe quick plug 8 to pass through the plate surface of the fixture 2, and the cooler liquid pipe quick plug 8 is connected to the coolant connection pipe outside the plate surface.

[0042] The coolant inlet pipe 3 and the coolant outlet pipe 6 are introduced from the outside of the fixture 2, the coolant inlet distribution pipe 4 is connected between the fixture 2 and the coolant inlet pipe 3, and the coolant outlet collection pipe 5 is connected between the fixture 2 and the coolant outlet pipe 6. Multiple coolers 7 can be connected between the coolant inlet distribution pipe 4 and the coolant outlet collection pipe 5. The coolers 7 are located on both sides of the single cell 1 and between the two plates of the fixture 2, and complete the flow of the coolant in the fixture 2 in an independent control or series manner.

[0043] There can be multiple coolant inlet main pipes 3 and coolant outlet main pipes 6 , respectively, and there can be multiple coolant inlet distribution pipes 4 and coolant outlet collecting pipes 5 , respectively.

[0044] Each cooler 7 has two cooler liquid pipe quick connectors 8, which serve as a coolant inlet connection point and a coolant outlet connection point respectively. The connection sequence and direction between different coolers 7 can be changed. The sequence brings about different temperatures in the direction of the coolant flow, resulting in different cooling conditions for the specific corresponding partitions of the single battery 1. This artificial change in cooling distribution can obtain the temperature setting on the plane of the single battery 1.

[0045] When using independent matrix partition control of cooling, each flow rate can be controlled to exceed the conventional cooling flow rate to stabilize the temperature of each partition. The temperature difference between the cooling inlet and outlet of the conventional stack is generally within 5°C, and the present invention is set to the conventional or different data.

[0046] Example 2

[0047] The present invention can select the coolers 7 to be connected in series or controlled independently.

[0048] When independent control is adopted, the difference between the inlet and outlet temperatures is within 1°C, preferably within 0.5°C, and more preferably within 0.2°C. That is, the practical measure is to stabilize the inlet temperature and increase the flow rate in parallel to establish temperature stability and repeatability in the area where the cooler is located.

[0049] When the series connection is adopted, it is preferred to imitate the coolant flow mode of the specific application, such as co-current or counter-current with hydrogen, or serpentine series connection, and its outflow temperature imitates the coolant outlet temperature of the application. This method can reduce the amount of temperature control fluid in the coolant temperature control device, and can reduce the investment cost of the peripheral fluid temperature and flow control equipment. One method of controlling temperature and flow is to control the flow of each coolant inlet main pipe 3 when controlling the temperature of each coolant inlet main pipe 3 to detect the temperature of each coolant outlet main pipe 6; the second method is to control the temperature of each coolant outlet main pipe 6 to detect the flow of the coolant inlet main pipe 3.

[0050] In the above series connection and independent temperature control, the detection of the single cell detector device is normally used. According to the occurrence of the single cell local current or voltage, humidity and other detection contents of the single cell detector device exceeding the control range, the overheating, overcooling, super current density output and other operations can be stopped. According to the purpose of the experiment, destructive experiments can also be carried out purposefully, that is, overheating, overcooling, super current density output, reverse polarity and other operations, to increase the experimental range and obtain data that is difficult to obtain under conventional experimental conditions.

[0051] Example 3

[0052] See also Figure 5 , parallel flow cooling structure in the short direction of the plate, showing the top view of the upper related connections of the single-sided fixture.

[0053] The cooler 7 sandwiched between the single cell 1 and the fixture 2 has the same inflow coolant conditions, i.e. the same temperature and unidirectional parallel cooling flow, producing simulated operating conditions with such a cooling layout. A corresponding similar fluid layout with coolant connected on the opposite side of the long side of the single cell and perpendicular to the fuel and oxidant flow fields can be simulated.

[0054] Example 4

[0055] See also Figure 6 , showing a top view of the upper connections of a single-sided fixture.

[0056] For the detection environment where fuel and oxidant enter and exit at the long end of a rectangular single cell, multiple independent examples with different inlet coolant temperatures and flow rate controls are provided. A connecting pipe 17 between multiple coolers 7 provides a selected cross-flow between the coolers 7. Among them, an independent coolant inlet main pipe A12 and an independent coolant outlet main pipe A15, an independent coolant inlet main pipe B13 and an independent coolant outlet main pipe B16, an independent coolant inlet main pipe C14 and an independent coolant outlet main pipe C17 respectively form circuits, and respectively control their inlet temperatures and flow rates to create differences in cooling conditions, provide detection zones at different temperatures, so as to establish tests on the effects of cooling local over-condensed water blockage and overheated dry film. The temperature difference between each inlet and outlet is within 1 °C, preferably within 0.5 °C, more preferably within 0.2 °C. That is, the actual measure is to stabilize the inlet temperature and increase the flow rate in parallel to establish temperature stability and repeatability in the area where this cooler is located.

[0057] Example 5

[0058] See Figure 7 , showing a top view structural diagram of the upper relevant connection of a unilateral fixture.

[0059] The same coolers 7 have an arrangement layout that is centrosymmetric about the long axis center and the short axis center of the single cell 1 plane in a matrix form. A plurality of serially connected connecting pipe groups A18 continuously between adjacent coolers 7 are used for end-to-end connection, and series cooling connections are independently formed in the four single cell plane regions formed by the two axes. This connection method is symmetric and uses the same coolant to cool the single cell 1. The flow connection in this example provides temperature change conditions, forming a layout where the cooling liquid in one of the regions s12, s11, s21, s22 gradually increases in temperature, and the other three regions are similar.

[0060] Example 6

[0061] See Figure 8 , showing a top view structural diagram of the upper relevant connection of a unilateral fixture.

[0062] Different from Example 3, the hardware structure is the same, only the multiple serially connected connecting pipe groups A18 and the multiple serially connected connecting pipe groups B19 are asymmetric, forming an adjusted and variable temperature layout.

[0063] As an example, for the purpose of forming a slightly lower regional temperature, that is, the temperature is s32 < s42 < s31 < s42. According to specific operating conditions, this temperature causes purposeful regulation of temperature, humidity, water precipitation, etc. to varying degrees in each relevant reaction zone, so that various corresponding data can be detected by the partition detector 11 and used for in-depth analysis of battery technology.

[0064] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A single cell test fixture with temperature zone setting, characterized in that: The fixture (2) has a cooler placement groove (9) on the inner side of the single battery (1), and the cooler (7) is fixed in the fixture (2) through the cooler placement groove (9). The contact surface between the cooler (7) and the fixture (2) has a heat insulation layer. The fixture (2) is provided with a partition detector (11) outside, and the partition detector (11) is in contact with the single battery (1) to be tested. A coolant inlet main pipe (3) and a coolant outlet main pipe (6) are introduced from the outside of the fixture (2). A coolant inlet distribution pipe (4) is connected between the fixture (2) and the coolant inlet main pipe (3), and a coolant outlet collection pipe (5) is connected between the fixture (2) and the coolant outlet main pipe (6). The cooler (7) is provided with two cooler liquid pipe quick plugs (8) serving as coolant inlets and outlets, respectively. One end of the coolant inlet of the cooler liquid pipe quick plug (8) is connected to the coolant inlet distribution pipe (4), and one end of the coolant outlet of the cooler liquid pipe quick plug (8) is connected to the coolant outlet collection pipe (5). A plurality of coolers (7) are connected between the coolant inlet distribution pipe (4) and the coolant outlet collection pipe (5), and the coolants flow in the fixture in a parallel independent control or return series manner between the plurality of coolers; The parallel independent control structure comprises: each cooler (7) is provided with a cooler liquid pipe quick plug (8) at both ends, the cooler liquid pipe quick plug (8) at one end is connected to the coolant inlet distribution pipe (4), a plurality of coolant inlet distribution pipes (4) are connected to the coolant inlet main pipe (3), the cooler liquid pipe quick plug (8) at the other end is connected to the coolant outlet collection pipe (5), and the coolant outlet collection pipe (5) is connected to the coolant outlet main pipe (6); The return series structure comprises: each cooler (7) is provided with a cooler connecting pipe (20) at one end, and an independent coolant outlet pipe or an independent coolant inlet pipe is provided at the other end, and the independent coolant outlet pipe and the independent coolant inlet pipe are alternately arranged; The coolers (7) can be connected in series or controlled individually.

2. A single-cell test fixture with temperature zone setting as claimed in claim 1, characterized in that: There are multiple cooling liquid inlet main pipes (3) and multiple cooling liquid outlet main pipes (6), and there are multiple cooling liquid inlet distribution pipes (4) and multiple cooling liquid outlet collecting pipes (5).

3. A single-cell test fixture with temperature zone setting as claimed in claim 1, characterized in that: The cooler placement groove (9) has a cooler pipe outlet hole (10) perpendicular to the plate surface of the fixture (2).

4. A single-cell test fixture with temperature zone setting as claimed in claim 1, characterized in that: The cooler (7) is a rectangular heat-conducting metal shell.

5. A single cell testing method with temperature zone setting, characterized in that: Each cooler (7) is controlled independently or in series; When independent control is adopted, the cooler (7) sandwiched between the single battery (1) and the fixture (2) has the same temperature condition for the inflow of coolant. The coolant enters from the coolant inlet main pipe (3), respectively along each coolant inlet distribution pipe (4) through the cooler liquid pipe quick plug (8) at one end to enter the cooler (7), then flows into the coolant outlet collection pipe (5) through the cooler liquid pipe quick plug (8) at the other end, and finally flows out through the coolant outlet main pipe (6); When the series control is adopted, the connecting pipe (20) between the multiple coolers provides a selected series flow between each cooler (7), wherein the independent cooling liquid inlet main pipe A (12) and the independent cooling liquid outlet main pipe A (15), the independent cooling liquid inlet main pipe B (13) and the independent cooling liquid outlet main pipe B (16), and the independent cooling liquid inlet main pipe C (14) and the independent cooling liquid outlet main pipe C (17) respectively form a loop to control their respective inlet temperatures and flows; The coolers (7) can be connected in series or controlled individually.

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