Central Air Conditioning Engineering Design for an Office Building in Shenyang

Abstract

Located in Shenyang (Cold Zone C), this office building is a high-rise structure consisting of 1 basement floor and 9 above-ground floors, with a total height of 48.15 meters and a building area of 28,616.2 m². It serves as an enterprise office building. The design aims to maintain an indoor temperature of 26 ℃ (60% relative humidity) in summer and 18 ℃ (50% relative humidity) in winter. Using Tianzheng HVAC calculations, the total cooling load is determined to be 1,501.09 kW (with an index of 113.32 W/m²), and the total heating load is 1,454.72 kW (with an index of 109.8 W/m²). System scheme: The ventilation system utilizes fresh air ducts to transport fresh air. Offices and similar spaces employ fan coil units combined with an independent fresh air system (with square diffusers for air supply from above and return air from below, and single-layer louvered return air outlets). Lobbies, ball game rooms, and similar spaces utilize an all-air system (with swirl air outlets for air supply and single-layer louvered return air outlets for return air). The water system in this design employs a closed, return-flow, two-pipe, primary pump system. The cold source equipment is selected as two water-cooled screw chillers (LS850H), while the heat source is connected to the municipal heat network (110/60℃) and exchanges heat through a BR0.2 heat exchanger. Equipment selection includes: chilled water pump ISG-125-200B, cooling water pump IS100-65-315C, and hot water pump IS100-65-315; the pressure maintaining and water replenishing equipment adopts a pressure tank V2-500-460 and a water replenishing pump ISG40-250; the water treatment equipment includes a softened water tank FRP-1.6, a DH-1 type softened water processor, etc. Energy conservation and protection: Equipment is equipped with soft hoses and shock absorbers for noise and vibration reduction; pipelines are insulated with foam rubber or centrifugal glass wool, and air ducts are protected against corrosion with epoxy zinc-rich primer and polyurethane topcoat. Condensate water pipes are protected against corrosion with PVC plastic pipes.