Invetigation On All Electrical Transport Refrigeration System

As rapid growth of Chinese economy,expectation on agricultural product quality starts to grow which stimulates an increasing need for cold chain market.Chinese transport refrigeration annual production increases from 40,000 ten years ago to a number of thousands of thousands now.As a major link of cold chain,transport refrigeration plays a very important role.However,Chinese market suffers from unequal standards,easy business entry threshold and market strategy which brings issues of unit energy efficiency and feasibility of evaluation.Direct drive(DD)refrigeration unit uses energy generated by engine and transforms into cooling capacity needed.Most units use on/off as temperature control logic which stops operation when target temperature reaches and restarts unit when target temperature is out of hysteresis range.This control compromises accuracy of temperature control.Electricity uses by the unit comes from vehicle,so energy loss due to control algorithm should be taken into consideration.Modification is made on an existing belt driven DD unit to all electric by using variable speed compressor/fan and EXV.To achieve higher energy efficiency with new designed algorithm.Through simulation,gain comparison results between baseline and electrical unit on performance and efficiency.Finally raise a way of evaluating unit annual efficiency and use this methodology on electrical and baseline system.The main research work and innovative points in the paper are listed as follows:1.Summarize of existing transport refrigeration technology and trend.An all-electric system is designed based on previous background research.The whole system using multiple variable electrical components is stemmed from belt driving system.2.Control logic of refrigeration system which includes compressor,EXV,condenser and evaporator is designed to allow system to adjust component output which can adapt different conditions and loads.3.Based on static simulation software,the transportation refrigeration system,including the above 4 main parts,is established.Comprehensive simulation is analyzed,aims to find the mutual coordination and improve the efficiency of the whole system configuration parameters and methods.4.National weather data is implemented to establish a methodology for annual COP evaluation which is used for a comparison between baseline and all-electric system.Efficiency improve percentage is gained by this method.Through simulation,unit design work and along with assembling is well guided.