Using the degree of superheat to judge whether the opening degree of the integrated test system of the power battery is appropriate, and using a thermometer to measure the difference between the temperature of the return pipe and the evaporating temperature (ie, the actual superheat) and the standard superheat (between 5-8 ° C) Check to see if the adjustment is appropriate. Using the suction pressure of the compressor as the saturation pressure in the evaporator, the table looks for an approximate evaporation temperature.
The temperature of the return pipe was measured with a thermometer, and compared with the evaporation temperature, it was between 5-8 ° C in the normal range. The inspiratory pressure value and the return air tube temperature must be read at the same time, otherwise the calculated actual superheat is not accurate.
If you feel that the degree of superheat is too small, you can turn the adjusting screw clockwise (that is, increase the spring force and reduce the opening degree of the thermal expansion valve) to reduce the flow rate; otherwise, if the degree of superheat is too large, the liquid supply is provided. Insufficient, the adjustment screw can be rotated in the opposite direction (counterclockwise) to increase the flow rate. Because the thermal expansion valve temperature sensing system in the actual work has a certain thermal inertia, the signal transmission hysteresis is formed, and the operation is basically stable before the next adjustment can be made.
It is judged whether the adjustment is proper by the shape change of the thermal expansion valve of the power battery integration test system. If the expansion valve body is completely frosted, it indicates that the flow rate is too small, and should be adjusted; if the adjustment is large, the frost shape does not change. If the expansion valve orifice is partially blocked, it should be cleaned; if the expansion valve body only has frost on the outlet side, indicating that the flow rate is too large, it should be adjusted small;
If the outlet side and the lower part of the expansion valve body are frosted at 45 °C, the inlet side should not be frosted, indicating that the adjustment is accurate and appropriate; if the expansion valve body only has frost on the inlet side, it indicates that the filter part at the inlet of the valve body is blocked and should be cleaned. If the expansion valve body is completely frost-free, it indicates no flow, the refrigerant may leak or the shut-off valve in the pipeline is not opened or the expansion valve is sensitive. The capillary leaks or the expansion valve orifice is blocked or the filter at the inlet of the valve body. Part of the blockage should be cleaned.
It is judged whether the adjustment is appropriate by the shape change of the frost at the suction pipe of the compressor of the power battery integration test system. If the ash is connected to the suction shutoff valve, it indicates that the flow rate is too large, and should be adjusted small; if the hoar frost is not To the suction pipe, the flow rate is too small and should be increased. In addition, it is judged whether the adjustment is appropriate by the magnitude of the pressure value on the low pressure side; whether the adjustment size is appropriate according to the uniform and complete condition of the evaporator coil frosting; under normal circumstances, the expansion valve is very quiet when working, if the emission is more obvious The sound of the wire indicates that the refrigerant in the system is insufficient. During the adjustment, it is not allowed to take rapid adjustment of the ups and downs, so that the refrigeration system is unstable and the control is not well controlled.
In addition to the above, the selection of the power battery integrated test system requires a corresponding after-sales service to provide technical support for the operation of the power battery integrated test system.