Ideas and measures to improve energy station energy efficiency and system energy efficiency-Part 2

The basic situation of the case project and the principle of system construction:

This paper takes the energy station in the terminal area of an airport as an example to discuss the strategies and practices for improving the energy efficiency of the energy station based on the principle of overall energy conservation of the system.

2.1 Basic information of the case project

According to the planning and the use characteristics of each building, the burden scope of the energy station includes the terminal building, the traffic transfer center and the aviation city business. It also provides a backup cooling source for the operation of the process air conditioner in the computer room of the command building. The total energy supply area is 1.02 million m2. The main service objects of the energy station are terminal buildings and traffic transfer centers. As large-scale transportation buildings, they have high security requirements and have some distinctive features: air and water transmission and distribution distances are long, air-conditioning terminals are mainly a large number of all-air systems, long operating hours, and a large energy consumption base. This places higher demands on the efficient operation of HVAC systems.

2.2 Clarify the energy consumption characteristics of service objects

Through the investigation of the actual energy consumption of air-conditioning systems in several terminal buildings, the sub-item energy consumption data of air-conditioning systems are obtained. The energy consumption of cold source preparation and the energy consumption of air-conditioning terminal transportation account for the largest proportion, and the two account for about 80% of the total energy consumption of the air-conditioning system. In the system construction, we should focus on improving the energy utilization efficiency of the source side and reducing the transmission energy consumption of the wind system.

2.3 Build a system that matches the energy consumption characteristics

A reasonable system construction includes three progressive levels: system form, determination and optimization of key system parameters, selection of equipment quantity and capacity allocation.

The case project adopted two measures to reduce the energy consumption of the wind system:

(1) According to load characteristics and usage requirements, ground radiation and radiant ceilings are used in areas with low probability of functional transformation in the later stage, and water is used instead of air to transport cold and heat, so as to improve the energy efficiency of unit cold (heat) delivery.

(2) According to the use requirements and space characteristics of the terminal building, a considerable number of all-air systems are required. These all-air systems use large temperature difference to supply air to reduce the air supply volume, so as to reduce the energy consumption of the air system transmission and distribution.

Two cold sources of different grades are installed on the source side, the high-temperature cold source and the normal-temperature cold source. The normal-temperature cold source is used to meet the large temperature difference requirements of air treatment, and the application of the high-temperature cold source can greatly improve the production efficiency of the cold source. In the system setting, the application range of high-temperature cold sources should be expanded as much as possible. Except that the sensible heat end of the air-conditioning system with independent temperature and humidity control uses high-temperature cold sources, all air-conditioning units of the all-air system use double coils to treat the air with heat and humidity. The coil supplies high-temperature cold water to realize the utilization of high-temperature cold source, and the secondary coil supplies normal-temperature cold water to realize large temperature difference air supply.

By Sammi