Abstract: The air conditioning scheme design of VAV system in petrochemical central laboratory is special (highly risky) and difficult. In this paper, the suitable VAV air conditioning schemes for central lab are analyzed, and the methods for simplifying VAV air conditioning scheme are also given. After that, the indoor environment automatic control scheme, control effect and energy consumption of several kinds of main air conditioning schemes are emphatically analyzed. At last, the optimized two automatic control ways, i.e., centralized and decentralized control and constant value and servo control, are put forward, and an optimized air conditioning scheme with independent air supply and air conditioning system, namely the centralized air supply and air conditioning scheme with double ducts, are proposed, which can be used for reference by designers of similar air conditioning schemes.

Key words: VAV, air conditioning scheme, indoor environments, automatic control