The constant temperature and humidity test chamber is how to achieve the temperature, cooling, humidification, humidity reduction?
The constant temperature and humidity chamber has the function of heating, cooling, humidifying and lowering humidity, so it accurately simulates the complex low temperature, high temperature, high temperature and high humidity, low temperature and low humidity environment of nature. Usually plastic, electronics, food, clothing, vehicles, metal, chemical, building materials and many other industries use constant temperature and humidity chambers to test the ability of products to withstand high temperature, low temperature and humidity; laboratories and research institutes can use constant temperature and humidity test chambers to test and design new products. So constant temperature and humidity chamber is how to achieve these 4 functions?
In order to explain how this works more clearly and understandably, we will divide it into two parts
一、Temperature and humidity system system
Refrigeration system is one of the key components of the constant temperature and humidity test chamber, is the entire design of the difficult point, the quality of its design directly affects the performance of the test chamber. My company commonly used refrigeration method is mechanical refrigeration, that is, steam compressor refrigeration; the use of mature refrigeration technology to ensure stable refrigeration performance, according to the user of constant temperature and humidity test chamber low temperature degree requirements of different, can be taken respectively single-stage refrigeration, double-stage refrigeration and complex stacked refrigeration. Its refrigeration principle is the same.
Refrigeration system by the compressor, condenser, throttling device, evaporator four major components. Compressor is the heart of the refrigeration system, it inhaled low temperature and low pressure gas, into high temperature and high pressure gas, through the condensation into a liquid to release heat, through the fan to take away the heat, so the test chamber below is the reason for the hot air, and then through the throttling into low pressure liquid, followed by the evaporator into low temperature and low pressure gas and then back to the compressor; refrigerant in the evaporator to absorb heat to complete the gasification process re and absorb heat, this process Continuously cycle, constantly heat exchange with the surrounding media will be heat to the surrounding media, to achieve the purpose of cooling, complete the constant temperature and humidity test chamber cooling process.
Heating principle is very simple, nickel-chromium alloy stainless steel tube heater with voltage at both ends, you can make it heated through the controller, and then through the hot air circulation to bring the heat to the box, so that the constant temperature and humidity test chamber heating.
Constant temperature and humidity test chamber humidification method is generally used steam humidification method, that is, low pressure steam directly into the test space humidification. This humidification method humidification capacity, fast, humidification control sensitive, especially in cooling can easily achieve forced humidification.
Constant temperature and humidity test chamber dehumidification there are two ways: mechanical refrigeration dehumidification and dry dehumidification. Mechanical refrigeration dehumidification principle is to cool the air to the dew point temperature below, so that greater than the saturation moisture content of water vapour condensation precipitation, so as to reduce the humidity. Dryer dehumidification is the use of air pumps will be constant temperature and humidity test chamber air pumped out, and dry air injection, while the wet air sent into the recyclable drying chamber for drying, dry and sent into the test chamber, so repeatedly cycle for dehumidification. Now most constant temperature and humidity test chamber using mechanical refrigeration dehumidification method, and dry dehumidification method, can make the dew point temperature to 0 ℃ below. Suitable for occasions with extraordinary requirements, but the price is more expensive.
So how do these functions smoothly follow our requirements to achieve low temperature, high temperature, high temperature and high humidity, low temperature and low humidity environment, here we can not do without the following described temperature and humidity regulation sensor
二 、Regulation sensors for temperature and humidity
1, constant temperature and humidity test chamber temperature adjustment sensor: constant temperature and humidity chamber temperature adjustment adjustment is through the built-in temperature sensor, data collection, by the temperature controller (micro information processor) regulation, connected to the air heating unit to achieve an increase in temperature, or adjust the refrigeration solenoid valve to reduce the temperature inside the chamber, in order to achieve the required temperature control.
2, constant temperature and humidity test chamber humidity adjustment sensor; the same, constant temperature and humidity chamber humidity adjustment is through the body temperature sensor, data collection, humidity controller (micro information processor) regulation, connected to the water tank heating elements, through the evaporation of water in the tank to achieve an increase in humidity or adjust the refrigeration solenoid valve to achieve the role of moisture, in order to achieve the required humidity control.