Application Study On Control System Of Temperature And Humidity In Coordinate Measuring Machine Laboratory

The coordinate measuring machine has a strict demand on the lab environment,such as temperature,humidity.According to the integration of process and control,a deep analysis and study has been carried out to this problem,the equipment selection,commissioning and operation have been completed,a satisfactory results obtained.Based on energy balance and thermodynamic principle,the reasons for the failure of temperature control of previous design are investigated,and the detailed heat dissipation for main apparatuses and personnel are provided.According to the specific condition of this application,the number and positions for air outlets and air inlets are allocated properly,furthermore a comprehensive simulation for temperature distribution is conducted to verify the process design.The difficulty for the temperature control in the lab is due to the big space and large lag,in addition,temperature uniform distribution in space is required.The control problem is taken into account when the process is designed.The previous control is examined and new control strategies are proposed: two water pipe systems are used,and their flowrates do not interrupt each other.Division plate is placed at the middle of water tank,thus the tank is divided into two parts,namely A side and B side.For the A side,the inlet water temperature of water cooling unit will be maintained at 11℃ via electric heating,thus making sure that the water cooling unit be at full load state and the outlet water temperature is controlled at 6℃;then the 6 ℃ water at B side is transported to the surface cooler of airconditioning box by its water pump,and the return water is pumped to the A side of water tank.A whole set of control system software is has been developed which possesses complete functions for industrial application,including start-up,operation,shut-down,monitoring of operation states and parameters,access to historical data,alarming,interlock protection,friendly operation interface.The whole system has been put into operation,it has been shown that the system is stable and reliable,every control requirement,e,g,temperature and humidity,is well satisfied.