Study On The Calculation Method Of Intermittent Heating Load

With the development of the economy and the improvement of living level, people's requirement for the indoor thermal environment becomes higher and higher. Heating regions enlarge southwards, most of which are in the hot summer and cold winter zone. Some public buildings are not used in the whole day and the using time has periodicity. The intermittent heating is usually used. But there are a few of contents and no provision about the calculation of the intermittent heating load in handbooks of the heating and air conditioning design. Considering the problems above, the paper analyses the effects on the intermittent heating load,which are caused by building envelope,air changes and heating mode in different zones, gives the calculation method of the intermittent heating.By taking the residential building and the office building in the hot summer and cold winter zone,the cold zone and the severe cold zone as the research object, building models are built. At first, effects caused by building envelope,air changes and heating mode in different zones are calcuilated by DeST and Designbuilder; and temperature changes and characteristics of heating load in bottom,standard and top floor rooms are analyzed; and the same parameters of southward and northward rooms are calculated. Then differences of simulation between DesignBuilder and DeST are analyzed and possible reasons are found.At last, annual cumulative heating load of the continuous heating and the intermittent heating are analyzed, then the initial investment and life cycle cost are also calculated.According to the research, the simulation results between DesignBuilder and DeST are basically identical. When building thermal requirements are satisfied, the intermittent heating additional factor for the residential building is 2%~15% in the hot summer and cold winter zone, 14% in the cold zone and more than 50% in the severe cold zone; for office building the additional factor is 10%~20% in the hot summer and cold winter zone, 25% in the cold zone and 30% in severe cold zone.All research results in this paper play a guiding role for the design of heating system in the engineering.