Recently, the 2023 annual central enterprise responsible person for business performance assessment A-level enterprise list officially released on the official website of the State Council State-owned Assets Supervision and Administration Commission (SASAC), a total of 49 central enterprises on the list.

On July 31, 2024, the General Meeting of the Editorial and Review Committee of HVAC and the 16th Working Meeting were held in Xi'an, with 76 members of the Editorial Committee attending.

Life is a journey of chasing dreams, and role models are the bright lights in the journey, illuminating the road ahead and giving the strength to move forward. The “focus on youth role models, promote the spirit of youth” of the original intention to open the “To Youth” column. In this issue, we invited Tao Xinwei, the industry design master (full name “2023 First China Pharmaceutical Engineering Design Association China Pharmaceutical Industry Engineering Design Master”), to share his work experience and his message to young engineers.

The Trane CenTraVac™ centrifugal chiller, for example, is one of the more reliable, efficient, low-emission and relatively quiet centrifugal chillers on the market today.

Air conditioning fan coil circulating cold (hot) air system, generally installed in the corridor within the decorative ceiling, and is divided into organized return air system and unorganized (using the ceiling space) return air system.

First, the refrigeration system pressure and temperature detection

(1) Refrigeration system pressure concept

Refrigeration system in operation can be divided into two parts of high and low pressure; high-pressure section from the compressor exhaust port to the throttle valve, this section is known as high-pressure; compressor suction port pressure is called suction pressure, suction pressure is close to the evaporating pressure, the difference between the two is the flow resistance of the pipeline; the pressure loss is generally limited to 0.018Mpa or less. Refrigeration system evaporating pressure and condensing pressure are in the compressor suction and discharge port detection. That is usually called the compressor suction and discharge pressure.