Research On Application Of Ground-Sink Direct Cooling And Heat Pump Complex System

As social economy rapidly developed,individuals have increasingly higher demand on comfort.Being a new air conditioning terminal,pipe radiation system has properties of high comfort and energy conservation.Nevertheless,existing standards and technical manuals do not have parameter selection table of pipe system,and selection in engineering process is depend on experience.Consequently,project planner could not exactly set capability of heat exchange of pipe,so lead to overheating or undercooling condition in room,which reduce thermal comfort and increase energy loss.In this paper,after detailed analysis of heat transfer,I found critical factors of heat transfer of floor pipe radiation heating and research relationship of them.Firstly,basing on principle of heat transfer and software,CFD was used to simulate room with floor pipe radiation heating,and then model accuracy was verified by constructing and testing pipe heating and cooling laboratory.After that,I used proofed model in univariate analysis concerned supply water temperature,in-pipe water velocity,pipe pitch,thickness of filler layer,thickness of structure layer,and material of structure layer,then draw qualitative and quantitative relationship of them with heat transfer per unit of pipe system.Research found that recommended supply water temperature range is 32-38?,in-pipe water velocity range is 0.05-0.2m/s,and pipe pitch is 20mm-40 mm,under which circumstance heat transfer would become more ideally.Followed by multivariate analysis of heat transfer per unit of pipe system using Matlab,I figured quantitative connection between multi-factors and heat transfer of pipe,and arrive at parameter selection table of floor pipe radiation heating system as well as the selection process.