System composition and working principle The automobile air conditioning road test system consists of temperature sensor, humidity sensor, wind speed sensor, flow sensor, pressure and temperature integration sensor, compressor speed sensor, solar radiation intensity sensor, multi-channel inspection instrument, frequency-voltage Converter, RS485-RS232 converter, RS232-USB converter, notebook computer, power supply device and other components. Temperature sensor, which converts the temperature inside and outside the car into electrical signals into the multi-channel inspection instrument. H1 ~ h3 is a humidity sensor, which converts indoor and outdoor humidity into electrical signals into the multi-channel inspection instrument. The wind speed sensor w1 is used to measure the wind speed of the evaporator; the wind speed sensor w2 converts the oncoming wind speed of the condenser into an electric signal and sends it to the multi-channel inspection instrument. q is a flow sensor, which converts the flow of refrigerant into an electrical signal and sends it to a multi-channel inspection instrument. P1 ~ p4 pressure and temperature integration sensor, which will convert the pressure and temperature of the high pressure side and low pressure side of the refrigerant into electrical signals into the multi-channel inspection instrument. r is a rotational speed sensor, which converts the rotational speed of the compressor into a frequency signal, and converts the frequency signal into a voltage signal through a frequency-voltage converter and sends it to a multi-channel inspection apparatus. i is a solar radiation intensity sensor, which converts the intensity of solar radiation into an electrical signal and sends it to a multi-channel inspection instrument. The multi-channel inspection instrument will process, calculate, and amplify the multi-channel signals transmitted by the above sensors, and then send the signals directly to the display for display. The other channel passes through the RS485 interface, RS485-RS232 converter and RS232-USB converter in the instrument. Go to the laptop. In the computer, the measured parameters are recorded, displayed and processed in real time through the configuration software. The real-time curves and historical curves are plotted, stored and printed. Road test process and data collection in the test The road test of the automobile air-conditioning system is usually performed in summer when the air temperature is higher than 35°C, and it is best to use the highest solar radiation intensity in the day from 1:00 pm to 3 pm : 00 this time. The test road should try to choose road sections that are straight, no slope, no sharp bends, traffic to and from roads with few pedestrians to ensure the accuracy and safety of the test. During the test, the test vehicle was first placed in the sun and sufficiently preheated to maintain a stable thermal load. Then start the vehicle and make it run at a constant speed of 20km/h. After the vehicle speed reaches the requirement, turn on the air conditioner to maximize the evaporator wind speed, and start the computer to run the configuration software. The software will automatically test the data tested during the test. Collecting, and real-time display, recording on the computer, draw the corresponding real-time curve and history curve, each speed is generally 20 ~ 30min test. After the 20 km/h isokinetic test is completed, the constant speed test of 50 km/h and 80 km/h can be performed continuously, and finally the idle test of 20 to 30 min is performed. You can also set the test content and test conditions, such as increasing the climbing test, traffic jam test, etc., as needed. Performance calculations on the refrigerant side In order to analyze and study the thermal cycling of automotive air conditioning systems and the calculation of cooling capacity, the most common method is to find several critical status points related to the refrigeration cycle on the pressure-enthalpy diagram and then perform Calculations. ZHONGSHAN LAVI HARDWARE PRODUCTS CO., LIMITED , https://www.lavihareware.com