Performance test system for cooling system of rail transit power converter

Abstract

The invention relates to the field of heat dissipation of rail transit power converters, in particular to a performance test system for a cooling system of a rail transit power converter, and a flow meter is connected to a water return pipe of a main pipeline of the cooling system and water outlets of branch pipelines; the thermometers are respectively connected to pipelines of the water inlet and the water outlet of the heat exchanger and branch pipelines of the water inlet and the water outlet of each power module; the differential pressure gauge is connected to the pipelines of the water inlet and the water outlet of the heat exchanger, the pipelines of the water inlet and the water outlet of the water pump and the pipelines of the water inlets and the water outlets of the power modules; the adjusting valve is connected to the main pipeline between the water inlet of the water pump and the water outlet of the heat exchanger. The system can realize the flow test of the main pipeline and each branch pipeline; when the cooling system operates under any working condition, the flow resistance curve of the water pump, the heat exchanger, the water cooling substrate and other components can be obtained by changing the flow of the pipeline; the heat loss of the converter and each component can be obtained by testing the temperature difference of the cooling medium of each component.

Description

Technical Field

[0001] The invention relates to the field of heat dissipation of rail transit power converters, and in particular to a performance testing system for a cooling system of a rail transit power converter. Background Art

[0002] In recent years, rail transit equipment is in a period of rapid development, and high-power power converters are widely used. Traction converters are an important part of AC transmission systems. The power modules in the converters (including IGBTs, diodes and other electronic devices) will generate a certain amount of heat. If the heat cannot be dissipated in a timely and effective manner, the efficiency of the power modules will be greatly reduced, and even the electronic devices will be damaged, making the converter unable to work properly. The converter cooling system dissipates the heat to the outside through the coolant flowing into the heat exchanger.

[0003] In recent years, product designers have conducted thermal design and analysis on the inverter cooling system. According to the structural characteristics of the inverter, through fluid mechanics simulation and calculation, they have conducted technical research on the pressure and flow of water cooling pipelines, the pressure and flow of air duct flow fields, and the flow distribution of branch pipelines. It is necessary to verify the consistency between the test results and the simulation calculation values.

[0004] When the cooling system of the rail transit power converter is tested for flow, the flow meter is connected to the cooling pipeline in the converter and the radiator pipeline in the cooling tower to form a closed cooling system. The converter water pump is started to drive the liquid flow in the cooling pipeline, and the volume flow of the cooling system liquid is tested by the flow meter; the specific situation is as follows: 1) Power converter and cooling system: The converter converts the single-phase AC power on the secondary side of the traction transformer into three-phase AC power with adjustable voltage and frequency. The main components of the cooling system include: water-cooled baseplate of the power module, water pump, cooling pipeline, etc. The heat generated by the power electronic devices in the power module is exchanged through the coolant in the water-cooled baseplate. The water pump serves as the circulating power for water cooling, and the coolant flows into the cooling tower through the cooling pipeline for heat exchange.

[0005] 2) Cooling tower: contains cooling fan and heat exchanger. The heat exchanger is forced to cool by the cooling fan above it.

[0006] 3) Flow meter: It consists of a flow sensor and a display instrument that receives pulse signals. It is used to measure the volume flow and total flow of low-viscosity fluids in closed pipes. It is connected through flanges, and there are sealing gaskets between the flanges to ensure the sealing of each interface.

[0007] The above cooling system flow rate test method has the following problems: 1) It is impossible to obtain the flow resistance curve and temperature difference of the water pump, heat exchanger and water-cooled base plate under any operating conditions in the converter cooling system.

[0008] 2) It is impossible to obtain the flow rate of each branch pipe in the cooling system and the flow distribution relationship between the main pipe and the branch pipe. Summary of the invention

[0009] In order to fully test whether the total pipeline flow and branch pipeline flow distribution of the cooling system meet the thermal performance requirements of the converter, the present invention proposes a performance testing system for a rail transit power converter cooling system, which can realize the flow test of the main pipeline and each branch pipeline; when the cooling system operates under any working conditions, the flow resistance curves of components such as water pumps, heat exchangers and water-cooled substrates can be obtained by changing the pipeline flow; and the heat loss of the converter and each component can be obtained by testing the temperature difference of the cooling medium of each component.

[0010] The present invention is implemented by adopting the following technical scheme: for a rail transit power converter cooling system performance test system, a first flow meter is connected to the return pipe of the cooling system main pipeline, and the remaining flow meters are connected to the outlets of each branch pipeline; the temperature probes of the first differential temperature gauge are respectively connected to the pipelines of the water inlet and outlet of the heat exchanger; the temperature probes of the remaining differential temperature gauges are respectively connected to the branch pipelines of the water inlet and outlet of each power module; the first differential pressure gauge is connected to the pipelines of the water inlet and outlet of the heat exchanger, and the fifth differential pressure gauge is connected to the pipelines of the water inlet and outlet of the water pump; the remaining differential pressure gauges are respectively connected to the pipelines of the water inlet and outlet of each power module; and the regulating valve is connected to the main pipeline between the water pump inlet and the water outlet of the heat exchanger.

[0011] The above-mentioned performance test system for the cooling system of the rail transit power converter drives the coolant to circulate, and the valve is adjusted to change the operating conditions of the cooling system. The pressure drop and flow value of the water pump, heat exchanger and power module are measured by the differential pressure gauge and flow meter to obtain the flow resistance curve of each component and the resistance loss on the converter cooling pipeline; the flow distribution relationship between the main pipeline and the branch pipeline is obtained through the tested flow value; When the power converter is running, the heat generated by the power electronic devices in the power module flows into the heat exchanger through the coolant in the water-cooled base plate for heat exchange. The heat loss of the converter and the power module can be obtained through the tested temperature difference table; When the pressure head provided by the water pump is balanced with the pressure head required by the pipeline, the flow rate provided by the water pump is determined, the working characteristics of the water pump in the converter cooling pipeline system can be obtained, and the relationship between the cooling pipeline system curve and the water pump characteristic curve can be obtained.

[0012] The above-mentioned performance test system for the cooling system of the rail transit power converter can test the flow value, pressure drop and temperature difference of the water pump, heat exchanger and power module of the cooling system at any working condition and at the same time by adjusting the valve.

[0013] In the above-mentioned performance test system for the cooling system of the rail transit power converter, when the flow meter is connected to the pipeline, the two ends of the flow meter are respectively connected to the straight pipeline of the flow meter outlet and the straight pipeline of the flow meter inlet through flanges, and the straight pipeline of the flow meter outlet and the straight pipeline of the flow meter inlet are also connected to corrugated flexible pipelines.

[0014] In the above-mentioned rail transit power converter cooling system performance test system, when the fifth differential pressure gauge is connected to the water pump, the two ends of the fifth differential pressure gauge are respectively connected through a flexible water pipe and a water pump water inlet quick connector and a water pump water outlet quick connector.

[0015] In the above-mentioned rail transit power converter cooling system performance test system, when the differential pressure gauge is connected to the power module, the differential pressure gauge is fixed to the frame of the power module through a fixed bracket, and the two ends of the second differential pressure gauge are respectively connected to the water-cooled base plate of the power module through a flexible water pipe, a right-angle elbow quick-connect connector.

[0016] The beneficial effects brought by the technical solution of the present invention are: (1) The flow, pressure drop and temperature difference of the water pump, heat exchanger and power module of the cooling system can be tested at any time under any operating conditions; (2) Through the measured flow rate and pressure drop, the working characteristics of the water pump in the converter cooling pipeline system can be obtained, and the relationship between the cooling pipeline system curve and the water pump characteristic curve can be obtained; the resistance loss on the converter cooling pipeline can be obtained; (3) The flow distribution relationship between the main pipeline and the branch pipeline under any working conditions can be obtained; (4) The flow resistance curves of water pumps, heat exchangers and power modules under any working conditions can be obtained; (5) The heat loss of the converter and power module can be obtained by testing the temperature difference of the cooling medium; (6) The system can achieve quick connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the cooling system performance test system.

[0018] Figure 2 Connect cooling system pipes and flow meters.

[0019] Figure 3 This is a schematic diagram of the water pump inlet and outlet pressure measurement.

[0020] Figure 4 This is a schematic diagram of the regulating valve connection.

[0021] Figure 5 Schematic diagram of power module inlet and outlet pressure measurement.

[0022] Figure 6This is the fitting curve of the water pump flow resistance, where fit2 is the second-order fitting curve and fit3 is the third-order fitting curve.

[0023] Figure 7 This is the power module flow resistance fitting curve.

[0024] In the figure: 1-first flow meter, 2-second flow meter, 3-third flow meter, 4-fourth flow meter, 5-first differential pressure gauge, 6-second differential pressure gauge, 7-third differential pressure gauge, 8-fourth differential pressure gauge, 9-fifth differential pressure gauge, 10-first temperature differential gauge, 11-second temperature differential gauge, 12-third temperature differential gauge, 13-fourth temperature differential gauge, 14-regulating valve, 15-straight pipe at water outlet of flow meter, 16-straight pipe at water inlet of flow meter, 17-corrugated flexible pipe, 18-flexible water pipe, 19-quick connector at water inlet of water pump, 20-quick connector at water outlet of water pump, 21-quick connector at right angle elbow, 22-water cooling base plate, 23-fixed bracket. DETAILED DESCRIPTION

[0025] According to the structural characteristics and working principle of the power converter cooling system, the present invention designs a cooling system performance test system ( Figure 1 ).

[0026] a) Working Principle The water pump in the cooling system drives the coolant to circulate in the direction of the liquid flow. The first flow meter 1 displays the total flow of the main pipeline, and the second flow meter 2, the third flow meter 3, and the fourth flow meter 4 display the flow of each branch pipeline (i.e., the power module).

[0027] The first differential pressure gauge 5 shows the pressure drop of the heat exchanger inlet and outlet, the second differential pressure gauge 6, the third differential pressure gauge 7, and the fourth differential pressure gauge 8 show the pressure drop of the inlet and outlet of each branch pipeline, and the fifth differential pressure gauge 9 shows the pressure drop of the water pump inlet and outlet. The first differential temperature gauge 10 shows the temperature difference of the heat exchanger inlet and outlet, and the second differential temperature gauge 11, the third differential temperature gauge 12, and the fourth differential temperature gauge 13 show the temperature difference of the inlet and outlet of each branch pipeline (i.e., the power module). The regulating valve 14 can change the flow change and pressure drop change of the water pump, heat exchanger, and power module.

[0028] b) Connection method The regulating valve 14 is connected in series to the main pipe between the water inlet of the water pump and the water outlet of the heat exchanger through a flange; the regulating valve 14 can be controlled manually or automatically.

[0029] The first differential pressure gauge 5 is connected to the pipelines of the water inlet and outlet of the heat exchanger; the second differential pressure gauge 6, the third differential pressure gauge 7, and the fourth differential pressure gauge 8 are respectively connected to the pipelines of the water inlet and outlet of the three power modules; the fifth differential pressure gauge 9 is connected to the pipelines of the water inlet and outlet of the water pump, and straight-through quick-connect connectors are installed on the pipelines, which are connected through high-pressure resistant hoses; the parameters of the differential pressure gauge are determined according to the pipeline pressure range, and can be displayed directly or through signal transmission.

[0030] The first flow meter 1 is connected in series to the return pipe of the main pipeline through a flange, that is, the water inlet of the heat exchanger; the second flow meter 2, the third flow meter 3, and the fourth flow meter 4 are connected in series to the outlets of each branch pipeline, that is, the outlet of the power module; the flow meter type and technical parameters can be determined according to the pipeline structure, fluid type and measurement range, and the temperature probe of the first thermometer 10 is respectively connected to the pipelines of the water inlet and outlet of the heat exchanger; the temperature probes of the second thermometer 11, the third thermometer 12, and the fourth thermometer 13 are respectively connected to the branch pipelines of the water inlet and outlet of the three power modules. The type and technical parameters of the thermometer are determined according to the installation structure, cooling medium, and temperature range.

[0031] c) Test methods The water pump drives the coolant to circulate, and the valve 14 is adjusted to change the operating conditions of the cooling system. The pressure drop and flow value of the water pump, heat exchanger and power module are measured by the differential pressure gauge and flow meter. The flow resistance curve of each component can be obtained. The resistance loss on the converter cooling pipeline can be obtained.

[0032] The flow distribution relationship between the main pipeline and the branch pipeline is obtained through the tested flow value.

[0033] When the power converter is running, the heat generated by the power electronic devices in the power module flows into the heat exchanger through the coolant in the water-cooled base plate for heat exchange. The heat loss of the converter and the power module can be obtained through the tested temperature difference meter.

[0034] The point where the water pump works in the cooling system mainly depends on the performance of the connected cooling pipeline. When the pressure head provided by the water pump is balanced with the pressure head required by the pipeline, the flow rate provided by the water pump is determined. The working characteristics of the water pump in this converter cooling pipeline system can be obtained. The relationship between the cooling pipeline system curve and the water pump characteristic curve can be obtained. Example

[0035] Flow meter connection Figure 2 As shown, taking the first flow meter 1 as an example, the two ends of the first flow meter 1 are respectively connected to the flow meter outlet straight pipe 15 and the flow meter inlet straight pipe 16 through flanges, and the flow meter outlet straight pipe 15 and the flow meter inlet straight pipe 16 are also connected to the corrugated flexible pipe 17.

[0036] Differential pressure gauge connection Figure 3 As shown, taking the fifth differential pressure gauge 9 as an example, both ends of the fifth differential pressure gauge 9 are connected by a flexible water pipe 18 and a water pump water inlet quick connector 19 and a water pump water outlet quick connector 20 respectively.

[0037] Regulating valve connection Figure 4 shown.

[0038] Power module pressure measurement such as Figure 5 As shown, taking the second differential pressure gauge 6 as an example, the second differential pressure gauge 6 is fixed to the frame of the power module through a fixing bracket 23, and the two ends of the second differential pressure gauge 6 are respectively connected through a flexible water pipe 18, a right-angle elbow quick-connect connector 21 and a water-cooled base plate 22 of the power module.

[0039] Water pump flow resistance curve fitting The pump flow resistance curve is fitted according to the main line flow and pump pressure drop test results.

[0040] Table 1 Water pump inlet and outlet pressure test data

[0041] Power module flow resistance curve fitting The power module flow resistance curve is fitted according to the branch pipeline flow and power module pressure drop test results.

[0042] Table 2 Power module inlet and outlet pressure test data

Claims

1. A performance test system for cooling system of rail transit power converter, characterized by: The first flow meter (1) is connected to the return pipe of the cooling system main pipeline, and the remaining flow meters are connected to the outlets of the branch pipelines; the temperature probes of the first differential temperature gauge (10) are respectively connected to the pipelines of the water inlet and outlet of the heat exchanger; the temperature probes of the remaining differential temperature gauges are respectively connected to the branch pipelines of the water inlet and outlet of each power module; the first differential pressure gauge (5) is connected to the pipelines of the water inlet and outlet of the heat exchanger, and the fifth differential pressure gauge (9) is connected to the pipelines of the water inlet and outlet of the water pump; the remaining differential pressure gauges are respectively connected to the pipelines of the water inlet and outlet of each power module; and the regulating valve (14) is connected to the main pipeline between the water pump inlet and the water outlet of the heat exchanger.

2. The performance test system for cooling system of rail transit power converter according to claim 1, characterized in that: The water pump drives the coolant to circulate, and the valve (14) is adjusted to change the operating conditions of the cooling system. The pressure drop and flow value of the water pump, the heat exchanger and the power module are measured by a differential pressure gauge and a flow meter to obtain the flow resistance curve of each component and the resistance loss on the converter cooling pipeline; the flow distribution relationship between the main pipeline and the branch pipeline is obtained through the tested flow value; When the power converter is running, the heat generated by the power electronic devices in the power module flows into the heat exchanger through the coolant in the water-cooled base plate for heat exchange. The heat loss of the converter and the power module can be obtained through the tested temperature difference table; When the pressure head provided by the water pump is balanced with the pressure head required by the pipeline, the flow rate provided by the water pump is determined, the working characteristics of the water pump in the converter cooling pipeline system can be obtained, and the relationship between the cooling pipeline system curve and the water pump characteristic curve can be obtained.

3. The performance test system for cooling system of rail transit power converter according to claim 2 is characterized in that: By adjusting the valve (14), the flow value, pressure drop and temperature difference of the water pump, heat exchanger and power module of the cooling system can be tested at any operating condition and at the same time.

4. The performance test system for rail transit power converter cooling system according to claim 1 or 2, characterized in that: When the flow meter is connected to the pipeline, the two ends of the flow meter are respectively connected to the flow meter water outlet straight pipeline (15) and the flow meter water inlet straight pipeline (16) through flanges, and the flow meter water outlet straight pipeline (15) and the flow meter water inlet straight pipeline (16) are also connected to the corrugated flexible pipeline (17).

5. The performance test system for rail transit power converter cooling system according to claim 1 or 2, characterized in that: When the fifth differential pressure gauge (9) is connected to the water pump, the two ends of the fifth differential pressure gauge (9) are connected respectively through the flexible water pipe (18) and the water pump water inlet quick plug connector (19) and the water pump water outlet quick plug connector (20).

6. The performance test system for cooling system of rail transit power converter according to claim 1 or 2, characterized in that: When the differential pressure gauge is connected to the power module, the differential pressure gauge is fixed to the frame of the power module via a fixing bracket (23), and both ends of the differential pressure gauge are respectively connected to the water-cooled base plate (22) of the power module via a flexible water pipe (18), a right-angle elbow quick-connect connector (21).

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