What are the similarities and differences between high and low temperature alternating heat and humidity test chambers and high and low temperature test chambers in Dongguan?
High and low temperature alternating heat and humidity test chambers and high and low temperature test chambers, the performance of these two devices is basically the same, but the control methods are different. The purpose is to pre-treat the product and the contents through repeated cycles of temperature from normal temperature to low temperature to high temperature, and then carry out routine tests to check that the products are in different circulation environments. Different changes in humidity, after simulating various climates or extreme climates, the ability of the product to withstand various environments.
The difference between the high and low temperature alternating heat and humidity test chamber and the high and low temperature test chamber is mainly in the control part. The control part of the high and low temperature test chamber is mainly controlled by the digital display instrument, and the high and low temperature alternating heat and humidity test chamber is controlled by the programmable controller. The digital display instruments are generally controlled manually. The commands that can be executed are generally single, and the programmable controller is fully automatic. You can set the parameters to be set and the number of tests in advance, and then set them according to the settings. The program works. Their cabinet structure is basically the same, and the technical parameters are the same.
The principle of high and low temperature alternating heat and humidity test chamber:
The high and low temperature alternating heat and humidity test chamber is composed of a refrigeration system, a heating system, a control system, a temperature system air circulation system, and a sensor system, and the above systems belong to two major aspects of electrical and mechanical refrigeration. The following is a preliminary description of the working principle and working process of several major systems.
1. Humidity system: The humidity system is divided into two subsystems: humidification and dehumidification.
2. Control system: The control system is the core of the comprehensive test chamber, which determines the important parameters such as the heating rate and accuracy of the test chamber.
3. Heating system: The heating system of the test box is relatively simple compared to the refrigeration system. It mainly consists of high-power electric resistance wire. Because the heating rate required by the test box is large, the heating system of the test box has relatively large power, and the bottom plate of the test box is also provided with a heater.
4. Refrigeration system: The refrigeration system is one of the key parts of the integrated high and low temperature alternating heat and humidity test chamber. Generally speaking, the refrigeration modes of the high and low temperature alternating heat and humidity test chambers are mechanical refrigeration and auxiliary liquid nitrogen refrigeration, and mechanical refrigeration uses vapor compression refrigeration, which mainly consists of a compressor, a condenser, a throttle mechanism and an evaporator.
6. Air circulation system: The air circulation system generally consists of a centrifugal fan and a motor that drives its operation. It provides a circulation of air inside the test chamber.
7. Sensor system: The sensors in the test chamber are mainly temperature and humidity sensors.
High-low temperature alternating heat and humidity test chamber system capacity and fault analysis?
High and low temperature alternating heat and humidity test chamber is an essential test equipment for aviation, automobile, home appliance, scientific research and other fields. It is used to test and determine the temperature environment changes of electric, electronic and other products and materials for high temperature, low temperature, damp heat or constant test. After the parameters and performance. Then, how is the internal temperature and humidity of the high and low temperature alternating heat and humidity test chamber controlled?
First, heating capacity
1. The heating device is the key link for controlling the heating of the high and low temperature alternating heat and humidity test chamber.
2. It is the controller that outputs the voltage to the relay when it receives the temperature rise command. About 3-12 VDC is added to the solid state relay; its AC terminal is equivalent to the wire connection; the contactor is also attracted at the same time. The voltage causes it to heat up, and the heat is brought to the tank by the circulating fan to heat the high and low temperature alternating heat and humidity test chamber.
3. The temperature reaches your set value quickly; the controller is adjusted by switching on the solid state relay.
4. We adjust the heat output on the screen in the high and low temperature alternating heat and humidity test chamber to adjust the heat output; this is the temperature control above 89 degrees, how to control the temperature stability below 89 degrees? The constant temperature and humidity test chamber is based on the heat output of the solid state relay on one side; the other is cooled by the compressor refrigeration cycle to achieve dynamic balance; the temperature is constant.
Second, cooling capacity
1. The important part of the high and low temperature alternating heat and humidity test chamber is the important parameter for judging the performance of a constant temperature and humidity machine. It consists of four components: compressor, condenser, throttling device and evaporator.
2. The compressor is the heart of the refrigeration system. It inhales low-temperature and low-pressure gas, turns into high-temperature and high-pressure gas, releases heat by condensing into liquid, and removes heat through the fan. Therefore, the temperature of the constant temperature and humidity machine is caused by hot air, and then by throttling The low-pressure liquid passes through the evaporator to become a low-temperature low-pressure gas and finally returns to the compressor; the refrigerant absorbs heat in the evaporator to complete the gasification process and absorbs heat, thereby achieving the purpose of cooling, and completing the cooling process of the constant temperature and humidity machine.
Third, the humidification capacity
Fourth, the ability to reduce humidity
The dehumidification system is also completed by the refrigeration system, and the evaporator is placed in the constant temperature and humidity test chamber; in the relatively cold, high-humidity alternating heat and humidity test chamber, the high-humidity gas will see the cold object condense into a liquid; thus repeating the high-humidity gas of the tank It will be rare to achieve the purpose of reducing humidity.
5. What are the fault analysis of the hot and humid test of the high and low temperature alternating heat and humidity test chamber?
The most common fault - humidification system
In the damp heat test, the actual humidity will reach 100% or the actual humidity will differ greatly from the target humidity?
Analysis: It may be caused by the drying of the gauze on the wet bulb sensor. Then check whether there is water shortage in the sink of the wet bulb sensor. The water level in the water tank is automatically controlled by a water level controller. Check whether the water supply system of the water level controller is normally supplied with water. Whether the water level controller works normally. Another possibility is that the wet gauze is hardened due to the long use time or the purity of the water supply, so that the gauze becomes hard and the gauze can not absorb moisture and is dry. The above phenomenon can be eliminated by replacing or cleaning the gauze.
The actual humidity and the target humidity are very different, and the value is much lower?
Analysis: Mainly the high and low temperature alternating heat and humidity test chamber humidification system does not work, check the water supply system of the humidification system, whether there is a certain amount of water in the water supply system, control whether the water level control of the humidifying boiler water level is normal, and whether the water level in the humidifying boiler is normal.
Automatic Bale Opener,Nonwoven Bale Opener,Bale Opener Machine,Mixing Bale Opener
Changshu Tianli Nonwoven Equipment Co., Ltd. , https://www.tianli-machinery.com