Scheme Determination And Economic Analysis Of Ice Storage System In An Office Building

The peak-to-valley load difference of the power grid is getting bigger and bigger,and the load pressure of the urban power grid is becoming bigger and bigger during the peak period.The air-conditioning electric load has accounted for 40%of the total electric load.The air-conditioning load peak and the electric load peak have the same changing characteristics.In order to alleviate the energy crisis,ice storage technology came into being.The energy pressure in our country also needs to be alleviated urgently.The ice storage air-conditioning system is widely used in some types of buildings due to its characteristics of balancing peak and valley electric loads as well as reducing the operating costs.The development process of the technology and the actual application technology status has been described in this article.The characteristics of ice storage technology have been analyzed also.Research shows that the ice storage system not only has the characteristics of balancing the grid load,but also has the advantages of wide application range,good economic benefits,and reducing the installed capacity of the equipment refrigeration host.Therefore,under the premise of peak and valley electricity prices,the ice storage system has been applied to an office building in Qingdao in this article.At the same time,the existing problems of ice storage technology were analyzed,the operation strategy analysis suitable for this project was formulated,and the ice storage system connected in series upstream of the main engine was adopted.Simulate the dynamic load of an office building in Qingdao by using annual load calculation and energy consumption analysis software V5.0 of Hongye.The office has the building area of 37696 m~2,which with the hourly cooling load crest value of the building is 3482 k W.The cumulative total cooling load for the whole day on the design day is 35552 k Wh.The design daily cooling load index of this office building is 92.3 W/m~2.on the basis of load analysis,the present paper analyzed several key issues that need to be paid attention to when calculating the air conditioning load when the ice storage system is used as the air conditioning cold source,that is,the load value and time at peak time,the contrast between peak load and low load,and the hours of typical design daily load distribution,and the calculation method to determine the equipment capacity.In order to ensure the reasonable operation of the ice storage system,the hourly operation strategy of the system under different air conditioning load rates have been analyzes,and uses this as a basis to determine the control operation mode of the system.The content also covered calculating the annual operating costs and initial investment costs with different ice storage rates(25%,30%,32%,36%,38%),as well as the corresponding curves together.Through the comparison with conventional electric refrigeration schemes,the static method is used to analyze the investment payback period corresponding to the ice storage rate under different operating strategies.The economic analysis of the system has also been carried out.It is concluded that the use of ice storage scheme is feasible in this case project.The use of ice storage system brings certain economic benefits.The corresponding ice storage rate with the shortest investment payback period is 30%,Compared with conventional electric refrigeration system,the investment payback period is 5.57 years and save operating costs by 29.3%/year.