Research On Several Issues About Actual Application Of Radiant Cooling Air-conditioning System

Calculation model of moisture load of traditional air-conditioning system is usedin radiant cooling system recently. However, radiant cooling system is sensitive toindoor moisture load. When the inexact calculation model is used, it will lead tocondensation if the moisture load is estimated smaller relatively and to increase theunnecessary energy consumption of fresh air handling unit if larger. In this article, asuitable calculation model of moisture load for radiant cooling system was given andapplied to actual cases analysis by a lot of investigation and experiments. Conclusionswere given as follows:1. Staff moisture load, plants moisture load and invading air moisture load werebasic composition of office building radiant cooling system moisture load. It wasinvading air moisture load in the peak period of the external door opening thatbrought the maximum risk of condensation to radiation cooling terminal. Infiltrationair moisture load could be neglected in the calculation radiant cooling system ofmoisture load, because it brought little influence to the inlet parameters of fresh airhandling unit. The moisture absorption and release of each indoor surface which hadonly function of peak load shifting had no effect on total moisture load in anair-conditioning period.2. The calculation model of moisture load for radiant cooling system given in thisarticle could reflect the composition and size of office building indoor moisture load.The error between model and actual test was controlled within reasonable limits. Themodel had certain guidance to the equipment collection of fresh air handling unit.In addition, the article discussed controlled parameters and running controlstrategy of radiant cooling system from the perspective of the coordination of air andwater system. Main conclusions were as follows:1. The control strategy of anti-condensation need to combine with design andconstruction. It was embodied in two aspects of Great idea and Small detail. Mainidea was regulation of water-side which to prevent radiant cooling terminal fromcondensation and air-side to make indoor dew point to return and staying normalvalue. 2. Spot investigations showed that it was necessary to regulate the sensible loadundertook by air and water system. According to the result of calculation, air-systemhad the ability of regulating indoor sensible load about±15~20%.3. The running control strategy was suitable for fixed and variable frequencyconditions of the water-system in the cases. And its advantage was more obvious inthe two ends and the hottest period of air-conditioning season.