The Introduction And Research Of Primary Pump Distributed Variable Flow System

Energy consumption of HVAC in China is about50%~70%of building energyconsumption every year, therefore saving energy consumption of air conditioning system is avery important content of building energy efficiency. In the large central air conditioningsystem, chilled water pump energy consumption accounted for about25%~30%of the entireair conditioning system energy consumption, therefore reducing the energy consumption forwater system is very necessary. So the research and application of primary pump variableflow system and secondary pump variable flow system of central air conditioning system isgradually popularized. But when the difference of different loop’s resistance is big, the twosystems have their own drawbacks. Primary pump variable water flow system in order tosatisfy the available pressure of the most unfavorable circuit, the speed of variable frequencypump is usually controlled by the constant terminal differential pressure control of the mostunfavorable circuit, this makes the available pressure of near-end users is much larger than thefar-end users, can only rely on the increasing of valve resistance to consume this part ofpressure head and results in waste. We can arrange secondary pump by different subareas tosolve the problem of the big difference of different loop’s resistance when Primary-Secondarypump variable flow system is applied, but due to the inherent drawbacks ofPrimary-secondary pump system, Which is in order to maintain the refrigerator’chilled waterflow constant, so primary and secondary pump should be arranged respectively, this causesthe initial investment of Primary-secondary pump system is much bigger than primary pumpvariable flow system. Refrigerating station takes up a large area. Pump efficiency is low andenergy consumption is high.“Low temperature differential syndrome” results in the decreaseof refrigerator’efficiency. so we introduce a new concept of Primary pump distributedvariable flow system, it means removing the primary pump based on Primary-Secondarypump distributed variable flow system. The new system will not only absorb the advantagesof primary pump variable flow system and Primary-Secondary pump distributed variable flowsystem, avoid the drawbacks of The new system will not only absorb the advantages ofprimary pump variable flow system and Primary-Secondary pump distributed variable flow system.This text shows the feasibility of Primary pump distributed variable flow system byintroducing xi ’an government main building engineering design and analysising the keypoints of Primary pump distributed variable flow system. Then use DeST-c software tosimulate the dynamic load of Xian Yang history museum, the economy Comparison wasmade by Primary pump distributed variable flow system and primary pump variable flowsystem of Xianyang history museum. We not only conclude that nergy saving effect isremarkable and relatively investment recovery period is short of Primary pump distributedvariable flow system of Xianyang history museum, How much loop resistance differenceis suitable for pump distributed system. At last,we summarize the problem which needs to befurther studied and advantages and disadvantages of Primary pump distributed variable flowsystem.