Data source: Beijing York Air Conditioning Maintenance http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3745369.
This automatic control system consists of temperature sensors, temperature controllers, electric three-way control valves that regulate the amount of cold water (in summer) or hot water (in winter) entering the air surface cooler, or electric control dampers that adjust the volume of fresh air, exhaust air, and primary return air. During the control process in the automatic control system, when the dew point temperature after the spray cooler deviates from the set value, the temperature sensor sends a dew point temperature deviation signal to the temperature controller. After calculation and amplification by the controller, an output instruction signal is generated to control the electric three-way valve in summer or winter, adjusting the amount (or temperature) of cold water (in summer) or hot water (in winter) entering the surface heat exchanger.
During the transitional season, the electric control damper adjusts the ratio of fresh air to return air while spraying circulating water, keeping the dew point temperature after the spray chamber constant, thereby achieving the purpose of controlling indoor relative humidity. The automatic control of the fixed dew point primary return air conditioning system is composed of two parts: room temperature control and indoor air relative humidity control.
Room Temperature Control: The room temperature control system consists of temperature sensors and temperature controllers placed within the controlled room. Through a selector, it controls the three-way (or straight-through) regulating valve of the air heater, achieving the purpose of controlling room temperature and supply air temperature.
Indoor Air Relative Humidity Control:
The indoor air relative humidity control system consists of temperature sensors (dew point temperature) placed after the spray chamber, temperature controllers, and through a selector, separately controlling the three-way regulating valve for spray water temperature, as well as the control dampers for fresh air, exhaust air, and primary return air, etc., as executive control mechanisms. This maintains the stability of the dew point temperature to achieve the purpose of stabilizing indoor air relative humidity.
How does York air conditioning adjust the dew point control of spray coil cooling?