Operational Characteristics Study Of Capillary Radiation Ceiling And Dedicated Outdoor Air System

The comfort and energy-saving effect of radiant air conditioning has been confirmed by the domestic and foreign research results. However, due to the regional climatic influences, in the popularization and application process there are also some problems existing, such as the problem of condensation, the problem that cooling and heating capacity is insufficiently, the problem of response of radiation air conditioning room temperature is slow. In order to find a suitable method to avoid and solve the problems of radiation air conditioning, give full play to the comfort and energy-saving advantages of the radiant air conditioning, based on the heat transfer mechanism of radiation air conditioning, and combined with experimental test method and CFD numerical simulation method, this paper researched the capillary radiation ceiling and dedicated outdoor air system.First, according to the characteristics of the experimental room building, the room air conditioning and cooling load calculation, determine the capillary radiation board, fresh air units, and the equipment of cold and heat source.Through establishment of capillary capillary radiation ceiling three-dimensional fluid-solid coupling model, analyse the heat transfer effect of capillary radiation ceiling by using the CFD numerical simulation method. Study the temperature of water supply, the flow rate of water supply, the indoor temperature impact on the capacity of capillary radiation ceiling. Furthermore, an air conditioned room numerical simulation model with the mannequin been builded. The distribution of indoor temperature, humidity and wind speed of radiation ceiling and dedicated outdoor air system been studied. The simulation results shoW that the average body surface temperature is highter than the indoor air temperature, the maximum temperature is in the head. In radiant cooling condition, the head temperature reached about 37 ℃, while in radiant heating condition, the head temperature reached about 36.2℃.Using experimental method to test the capillary ceiling radiation and independent air system and indoor thermal environment, come to the interior ceiling, wall, indoor air temperature response characteristic, and capillary condensation of moisture. The test results show that when radiation cooling ceiling alone and seting the Water temperature to16℃, the capillary wall condensation appear a large number of condensation of moisture, setting capillary water temperature to 18℃, the capillary wall appear a small amount of condensation of moisture, when radiation ceiling and dedicated outdoor air cooling, the capillary wall does not appear condensation of moisture.Optimized the control hardware configuration of the capillary radiation ceiling and dedicated outdoor air system, designed radiant air conditioning system monitoring interface. Develop a reasonable control strategy, designed to achieve a real-time monitoring program and interface of the indoor temperature, humidity, water temperature and other parameters when capillary ceiling radiation and independent air system system during operation.Using heat transfer knowledge, carried out the mathematical model ceiling radiation heat transfer process, analysis of the genetic algorithm to optimize PID parameters and fuzzy PID control algorithm theory, and applied them to optimal control of capillary radiation ceiling and dedicated outdoor air system. The simulation results show that, when seting the parameters value of the PID controller to, Kp = 4.94, Ki = 0.15, Kd = 0.08, adjustment time of fuzzy PID control system dropped from 620 s to 560 s compared to conventional PID control, While the fuzzy PID get a superior dynamic characteristic on the effect of interference signal.