Energy Consumption Analysis And Optimized Strategy Research Of Chilled Water Equipment In Variable Primary Flow Chilled Water System

Building energy saving is focused in china,various building energy-saving technology is also evolving.The energy consumption of air-conditioning system is an important part of the building energy consumption,as part of its energy-saving technology,variable primary flow chilled water system,which has the obvious energy saving effect has arise more attention.This paper introduces the constitution and technological requirement of variable primary flow chilled water system,and analyzes the summer energy consumption question of chilled water equipment in variable primary flow chilled water system from the design stage.According to project example, chilled water equipment optimization plan of variable primary flow chilled water system was given.The influence of water chiller energy consumption's partial load assignment strategy,number and capacity are analysed in the paper which bases on the building air conditioning dynamic load.Energy consumption equation of water chiller and the constraints are established,at the same time,the paper makes use of the genetic algorithm to optimize the energy consumption equation.Based on water pump's similar principle,obtains the water pump frequency conversion best governor deflection using the graphic method under the inferential reasoning different rotational speed chilled water pump's characteristic parameter,and establishes the actual pipe network characteristic curve equation,then gives the chilled water pump energy consumption equation of the several control modes.Taking an office building in Xi'an as an example,simulates the dynamic air conditioning load of this building with DeST-c which was invented by Tsinghua University,and uses the air-conditioning cooling load time frequency(CLTF ) to count the air-conditioning load.On this basis,analyses the energy consumption of different selected programs which are water chillers and freezers,draws the conclusion:Obtains water chiller selecting optimization plan two through the genetic algorithm toolbox, which conserves energy 13.9%,11.9%separately compared to commonly plan one (equal capacity of two pumps,when the load rate is greater than 50%,one as the main equipment,another auxiliary)and plan two(equal capacity of two pumps,when the load rate is greater than 50%,equal distribution);Chilled water pump is another key to saving energy in variable primary flow chilled water system,its energy saving rate are different along with the flow and the load rate,the summer energy consumption from low to high followed by constant differential temperature control,constant terminal differential pressure control and constant differential pressure control;Chilled water pump is another key to saving energy in variable primary flow chilled water system,its energy saving rate are different along with the flow and the load rate,the summer energy consumption from low to high followed by constant differential temperature control,constant terminal differential pressure control and constant differential pressure control;From the energy saving point of view,in variable primary flow chilled water system,constant differential temperature control and constant terminal differential pressure control should use a chilled water pump,but constant differential pressure control should adopt two chilled water pump(regulating number and frequency conversion).The chilled water equipment optimization plan which is given in the paper may provide the beneficial reference for designing of variable primary flow chilled water system in future.