High-precision constant temperature and humidity air conditioner is a precision air conditioner that uses intelligent control to keep the temperature and relative humidity in the room within the upper and lower deviation range. It is equipped with humidification components, heating components, refrigeration components, air supply system, control system and other parts.
Four functions of high-precision constant temperature and humidity air conditioner:
The control principle of high-precision constant temperature and humidity air conditioner is very simple. The common one is to automatically operate the relevant components according to the difference between the current temperature and humidity and the set temperature and humidity. However, this control has three major disadvantages:
1. Waste of energy
For example, when the air-conditioned room is first put into use, its temperature is far from the set value. At this time, whether it is a water system air conditioner or a fluorine system air conditioner, its related components are maximized, so that the air supply temperature is too low (in summer) or too high (in winter), and then it is necessary to compensate by cooling or heating to put the temperature in the appropriate range. This process is extremely energy-consuming on the one hand; on the other hand, it may also cause discomfort to the human body; on the other hand, it may also cause damage to instruments, equipment, furniture and even building decoration.
2. Reduce the air comfort in the room

For example, if the indoor temperature sensor detects that the indoor temperature has risen, the controller issues a command to increase the opening of the cold water valve. After that, the cold water flow into the coil will increase, lower its surface temperature, and lower the temperature of the air passing through the coil. This will take a certain amount of time. Then, the lowered air will be transmitted to the room to mix with the indoor air and lower the temperature of the temperature sensor. This will take longer. When the temperature sensor detects the lowered temperature and needs to reduce the valve opening, the coil is full of low-temperature cold water, which continues to lower the indoor temperature, which will cause the room to be overcooled. A similar situation will occur during heating, causing the room to be overheated.
High-precision constant temperature and humidity air conditioning chilled water system
3. Large indoor temperature fluctuations
The huge thermal inertia and time lag of conventional control methods cause large indoor temperature fluctuations. From overcooling + heating compensation, after a short period of stability, overheating occurs due to heating lag, and cooling starts to offset. This cycle is a vicious cycle of continuous temperature fluctuations.
So, how to achieve high-precision constant temperature and humidity air conditioning control? Through the above analysis, we believe that the use of high and low limit control of supply air temperature and humidity is an effective method. Take necessary measures to limit the supply air temperature to an appropriate range. When the indoor real-time temperature (sometimes replaced by return air temperature) T1 is low (in winter), the output signal of the controller will control the heating valve to a certain maximum opening degree so that the supply air temperature does not exceed the preset upper limit temperature. In summer, when the indoor real-time temperature is very high, the output signal of the controller will control the cooling valve to a certain maximum opening degree so that the supply air temperature does not fall below a preset lower limit value.
Since the temperature sensor is close to the outlet of the cooler and heater, possible changes in the system state can be detected in advance. At this time, if the controller is controlled by its detection signal at a strength of one-tenth of the indoor temperature signal, it means that once the cold water valve or heating valve is driven by the controller to increase the opening degree, it will quickly receive an instruction from the controller to make it slightly converge due to the rapid response of the supply air temperature sensor T2. For example, according to the signal detected by sensor T1, the opening degree of the cooling valve should be increased to 50%. After the cold water flow is increased, the supply air temperature sensor T2 quickly detects the temperature drop, and then uses its predetermined control force to make the cooling valve move in the direction of closing the valve through the controller, so that it is slightly closed, that is, the opening degree is not 50%, but may be 45% or less. In this way, the control effect can be greatly improved, and the indoor temperature fluctuation amplitude can be greatly reduced.