Energy Efficiency Analysis Of Control Method Of Primary Pump Systems With Variable Flow Rate

As economy developing,the proportion of energy consumption of HVAC in total energyconsumption of building is rising.On the other hand,caused by the condition of ourcountry,our per capita resource is relatively insufficient. So trying to reduce the energy ofHVAC system is critical for sustainable economic development. At present,in our countrymost HVAC system keep working at constant flow rate condition.In other words,pumpsaways keep working at the design flow rate condition.However,for most of time HVACsystem working at part load condition,so that,that generates a large part of unnecessary energyconsumption.For this reason,many scholar begin to engage in primary pump system withvariable flow rate research.Besides,as frequency conversion technology and chillermanufacturing technology improving, primary pump system with variable flow rate used inEngineering practice is becoming available.In addition,for primary pump system with variableflow rate,how to control the speed of pump according to the load condition is an importantissue,which will directly affect the energy-saving effect of variable flow rate system.This essay sets up a constant flow rate test-bed and other test-beds corresponding to allkinds of control method by simulink software.By running simulation test-beds,this essay findsthat the COP of chiller of primary pump systems with variable flow rate, compared to theconstant flow system,does not decline obviously and total energy consumption does not rise alot yet.So it proves primary pump system with variable flow rate is available.In another hand,according to existing control method this thesis gives a new control method-Maximum valveopening control method. Moreover,by running simulation,this thesis finds the energy-savingeffect of maximum valve opening control method is the best,constant pressure of the endcontrol method is better,constant pressure of main pipe control method is good.And this thesisalso find the controlling accuracy of constant temperature control method is low and has somelimitation in practice. In this paper, a theoretical analysis of primary pump system withvariable flow rate is performed.It can be a reference for future research.