Research On Control Strategy Of Radiant Floor Cooling System In Office Buildings

The radiant floor cooling system has better energy storage characteristics and thermal comfort,because of inert radiation terminal.The system can save investment and building space,because the pipeline system can be shared in summer and winter.Radiant floor heating system has been widely used in winter,and its application range is affected by the immature regulation mode in summer.Therefore,it is necessary to explore a comfortable and energy-saving regulation method of radiant floor cooling system,which is conducive to its promotion and application.This paper takes the radiant floor cooling system as the object,proposing intermittent operation and weather-forecast-based predictive controls.Using TRNSYS simulation software as the research tool,a typical air-conditioning system model of an office building in Jinan was established to analyze indoor temperature,humidity and energy consumption.By comparing the radiant floor air conditioning system and fan coil system,when the parameters of water supply are the same,the indoor temperature under fan coil is higher than the indoor temperature under the radiation end about 2 °C.The intermittent control of radiant floor cooling system was studied by controlling the running time of the system.The original operation plan of the system is that the direct supply system runs 24 hours continuously in the cooling season,and the displacement ventilation system runs from 8:00 to 18:00 on weekdays.Under the premise that indoor temperature and humidity meet the design specifications of air conditioning,two schemes can be provided.The first scheme is that the cooling system directly linked by buried pipes will operate in accordance with the original scheme,and the displacement ventilation system will be closed for 1 hour in advance,the second scheme is that the cooling system directly linked by buried pipes will be operated continuously during the working day,and the displacement ventilation system will be closed for 1 hour in advance.Two situations can be set according to the working time,one is that the total load of personnel is a fixed value,the other is that the total load of personnel changes with time.The intermittent regulation scheme is applied in these two cases.The study shows that the first scheme is suitable for working during holidays,with an energy saving rate of 3.3%.Plan 2 is applicable for no working during holidays,with an energy saving rate of 7.5%.Intermittent control scheme is more suitable for the situation that the total load changes with time.The air conditioning system is adjusted and controlled in advance by means of weather forecast.The prediction of outdoor meteorological parameters is the basis and premise of operation control.The main parameters affecting the load include temperature and solar radiation.By comparing the forecast meteorological data with the typical meteorological annual data,this paper studies the special weather in the forecast data,such as high temperature weather,cloudy and rainy weather,and also predicts the change of equipment and personnel load in the building.The research suggests that when predicting temperature is higher than typical meteorological data respectively 2 ~ 5°C and 9°C,should increase the water flow to maintain indoor temperature.When predicting temperature lower than the typical weather temperature of 2 ~ 6°C,need to reduce the water flow for energy saving in advance.When the change of equipment and personnel quantity leads to the change of indoor load reaching more than 15% comparing with the original load,it is necessary to increase or reduce the water supply flow to maintain indoor temperature and humidity to meet the standard,and achieve the purpose of reducing energy consumption.