Xining Caojiapu Airport Expansion Project in Qinghai: Multi-Stage Indirect Evaporative Cooling High-Temperature Water Chiller Unit Project Project Overview

This airport expansion project is a key airport construction initiative planned for the "14th Five-Year Plan" period in Qinghai Province. Upon completion, it will become a major aviation hub in the eastern part of the Qinghai-Tibet Plateau, with an expected annual passenger throughput exceeding one million. The project includes the expansion of the terminal building, a comprehensive transportation center (GTC), and supporting facilities. Given the region’s summer characteristics of "high temperature and low humidity," the cold source system design must meet the core requirements of "high efficiency and energy savings, stability and reliability, and green low-carbon emissions." Aolan evaporative cooling products can replace mechanical air conditioning in dry regions, achieving an energy saving rate of over 70%.

Solution Implementation

This design employs nine Aolan multi-stage indirect evaporative high-temperature water chiller units, installed on the west side of the GTC parking building, to provide chilled water as the cold source for the refrigeration station. The cold source system of the station includes multi-stage indirect evaporative water chiller units and a water thermal energy storage system (serving as a backup cold source), catering to the airport terminal building and the comprehensive transportation center (GTC).

To ensure water quality in the cooling supply system, the air conditioning system and the indirect evaporative high-temperature water chiller units exchange heat indirectly via plate heat exchangers. The multi-stage indirect evaporative high-temperature water chiller units are equipped with built-in circulation pumps and plate heat exchangers, as well as water quality detection and treatment devices, to minimize scaling issues in the units and heat exchangers.

The cooling supply system of this refrigeration station provides three types of cold source parameters to meet the needs of different end-use equipment:

• 1.Low-temperature parameter: 7/12°C, supplied by the thermal energy storage water tank;

• 2.Medium-temperature parameter: 16/21°C, supplied by the evaporative cooling high-temperature water chiller units;

• 3.Under extreme weather conditions, a combined cooling supply mode of thermal energy storage and evaporative cooling is adopted;

• 4.High-temperature parameter: 21/26°C, achieved through the cascaded utilization of medium-temperature return water, further increasing the inlet water temperature and efficiency of the evaporative cooling units.

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Performance Demonstration

The project commenced operation in 2025. After system debugging and optimization, the equipment has been running stably. Through "technology adaptability + intelligent control," the Aolan multi-stage indirect evaporative cooling high-temperature water chiller units have successfully addressed the multiple challenges of climate, load, and environmental protection in the expansion project of this Qinghai airport. This provides an "efficient, low-carbon, and reliable" innovative solution for the cold source systems of large public buildings in high-altitude, arid regions.