Energy Saving Study Of Variable-frequency Regulating For Marine Air Conditioning

The operation loads of the air conditioning(AC)system on the ship are designed according to the worst operating condition,in order to ensure the safety and comfort of the vessels.Ship AC system for about 85%of the time running under partial load,its load only accounted for 60?80%of the rated load.Traditional ship AC system uses the constant speed and constant power operating mode,which causes a lot of energy waste.China as the world's first shipbuilding country,the ship's frequency conversion and energy saving technology has a huge market and bright prospects.This thesis based on the theory of ship AC heat load analysis,and is to research ships operating in the different time,different regions of AC system heat loads.The variation of the heat loads of ship AC system has been comprehensively analyzed.Taking Yu kun vessel as example,the analysis results show that the proportion of heat of fresh air in the loads of ships AC accounts for 46%,which is the biggest proportion in the load.The thermal loads of the system is obviously affected by the influence of ambient temperature,the average growth of 1?,and the system loads would increase 77 kW.In addition,The energy consumption of each component of the ship AC system is analyzed,and the mathematical model of each subsystem in steady state operation is established.Taking Yu Kun vessel as research object,the simulated results show that the maximum energy consumption in all subsystems of energy consumption is the refrigeration unit,which accounted for 65.68%.The chilled water system consumes least and accounted for 3.18%.After applying the frequency conversion control technology to the ship AC systems,the influence of variation of AC heat load on the performance of ship variable frequency AC system.Also,the influence of the performance of ship AC system of chilled water inlet temperature and cooling water inlet temperature from the angle of low energy consumption,high refrigeration has been analyzed.The simulated data show that when AC system heat load drop from 100%to 40%of designed rated load,the energy consumption of AC system can save 288 kW,and the saving ratio is 72.7%.When the chilled water inlet temperature is 6 ?,the AC systems consumes lowest energy,just is 394.3kW.When the chilled water inlet temperature drop from 30 ? to 25 ?,the system can save 49 kW energy,and the saving ratio is 12.7%.According to the research results,this thesis presents a variety of AC system frequency conversion transformation strategy,and taking Yu Kun vessel as an example,These have been calculated that the performance of ship AC system and transformation of the initial investment and saving funds and other economic indicators.The calculation results show that after applying the transformation scheme of the frequency conversion control technology,the saving rate is up to 30.2%.