Performance analysis and economic evaluation of valley power phase change cold storage air conditioning system applied to a large commercial supermarket

Taking the air conditioning and refrigeration project of a commercial supermarket in Shenzhen as an example,combined with the peak-to-valley electricity price difference,the performance analysis and economic evaluation are conducted on the application of hydrated salt phase change cold storage technology in the large-scale comfortable commercial field.This project utilizes the backup refrigeration unit in the existing refrigeration room as the cold source,and the phase change cold storage unit uses valley power to store cold at night,and supplies the cold energy to the air conditioning and refrigeration system of the commercial supermarket during the day to meet the cooling needs of users.In this paper,the experimental data of cold storage/discharge temperature,cold storage capacity and power consumption of the valley power phase change cold storage system are systematically tested and analysed for 14 days.The results show that compared with the original refrigeration system,using the valley power phase change cold storage system as the cold source,the refrigeration unit coefficient of performance (COP) and system energy efficiency ratio (EER) in night are significantly improved.The payback period of the project is 5.35 years,and with the gradual widening of the peak-to-valley electricity price difference,when the peak-to-valley electricity price difference is not less than 1.06 yuan/(kWh),the payback period of the system can decrease to less than 4 years.It is feasible to apply hydrated salt phase change cold storage technology combined with valley power/curtailment power to the field of large-scale comfortable commercial air conditioning.