The air conditioning load of large shopping malls is mainly divided into heat transfer load of envelope structure, heating value of lighting inside shopping malls, personnel load and fresh air load. Large shopping malls have large building area, large internal space and large shape coefficient; Moreover, at present, many large-scale shopping malls use large-area glass curtain walls, which leads to huge load transfer through the envelope structure; There are many kinds of goods in shopping malls, and there are many partitions and counters to display goods, which leads to an increase in lighting for commodity display. Coupled with the daily lighting in shopping malls, the energy consumption and the load brought by lighting in shopping malls also increase. The flow of people in large shopping malls is very large, and the density of people changes greatly with time. Generally, the flow of people reaches the maximum in the afternoon and evening, which makes the heat and humidity load of people in shopping malls larger, and the heat and humidity load varies greatly at different times.
At present, in large shopping malls, there are several ways to choose refrigeration units: 1. Scheme 2 of water chiller+electric boiler. Scheme 3 of ice storage+gas boiler. Scheme 4 of steam lithium bromide refrigerator+steam hot water heat exchanger. Scheme 5 of direct-fired lithium bromide refrigerator. The scheme of screw air-cooled chiller+air source heat pump is actually selected according to the convenience and economy of various cold and heat sources.
Most air handling systems adopt all-air handling system (low-speed air duct centralized air supply system). Various air handling systems such as fan coil unit+fresh air unit system and independent ceiling air cabinet are compared, and it is concluded that the all-air handling system is the best choice. The system has an independent air-conditioning room, where fresh air and return air are treated centrally and then sent to each partition through air ducts; The air volume of the system is large, the section size of the air duct is large, and the total length of the air duct is long; However, the air pressure drop is large, and the required fan power is large; The area of air-conditioning machine room is relatively large, accounting for 4.5%~6.5% of the whole air-conditioning area.
At present, in the air conditioning system of most large shopping malls, energy consumption is very large whether using the above refrigeration units or air handling systems.