Design of Cold and Heat Source for Central Air Conditioning of a Commercial Center in Shanghai

    This paper is mainly for a commercial center in Shanghai cold and heat source of the program design。 The current air-conditioning cold and heat source technology presents an increasingly persified trend, energy use, variety and utilization efficiency are greatly improved, building air-conditioning system, cold and heat source is more and more important。 According to the design specifications and engineering design procedures required by this specialty, the design and selection of the cold and heat source of the central air conditioning of the commercial center are carried out according to the problems faced by the cold and heat source in the design of the current air conditioning cold and heat source。 In-depth study of the entire design process with economic and safe energy as its principle to the comfort of the indoor environment for the purpose of the design。

    Large-scale construction of cold and heat source system design is generally three stages, namely, program design, preliminary design and construction design。 In the design of the program, according to the construction project content and scale, the initial consideration of the cold and hot program, a rough estimate of cold, heat load and chiller group and other issues, calculate the chillers and auxiliary equipment layout required area, cooling tower layout required Area, to determine the cold water room, cooling towers, storage tank location and construction area。 In the design stage, the design content is mainly based on the design description, and the design scheme, design feature and system form are discussed in the form of text description, and the general plan of the program design is appropriate。 Specific steps In order to understand and familiar with the requirements of the indoor environment in the design task book, we need the necessary site survey to understand the external conditions, find out the supply parameters such as cold and heat source, water supply and drainage pipe, energy and so on, Familiar with the design task book on the cold and heat requirements, control the relevant standards, according to the building size and grade to determine the indoor design parameters and hot and cold load estimates; design range according to the requirements of the design requirements, according to the design basis Meteorological data, load calculation of the basic data, process data, water and electricity and other energy supply of fuel, design specifications, engineering design information, the construction unit put forward the basic recommendations and requirements to explain; cold and hot source system program parameters Calculation and general drawing should be based on the professional to provide the building categories, building plans and other technical parameters and information, and in accordance with the country's current cold and heat source design standards, norms and other program design。 The design diagram includes the flow chart of the cold and heat source system, the layout of the equipment piping plan, the main equipment and the pipeline, which can clearly show the whole project of the cold source and the heat source system。

    The design of the main use of closed centrifugal chillers, constant flow of hot and cold water pumps, plate water - water heat exchangers and other equipment combined design。 This is because。 Commercial building design Air conditioning system is to maintain the appropriate room temperature and humidity, so that customers feel comfortable when entering the building comfortable environment; in addition to the indoor environment to prevent the deterioration of the quality of goods; while the comfortable environment to the staff a good working environment。 The cold load of the building is calculated by the method of cold load calculation, including the building's envelope structure, human body heat dissipation, fresh air volume, equipment, lighting equipment and so on。 According to the results of the load calculation to determine the program, the drawing on the drawing of the enthalpy diagram and marked the status of each room, the calculation of the state point under the relevant data for equipment selection。 There are relevant design manuals to place the room equipment and system equipment, and the location of the water pipes and ducts。 According to the location of the duct and the water pipe, the size of the hydraulic calculation to ensure that the system is running properly。 Hydraulic calculation is based on Hongye equipment design HVAC software in the drawings of the water pipe duct to extract the calculation, according to the different diameter, pipe length and so on to calculate and get the most unfavorable loop。 Followed by the choice of cold and heat source equipment, according to the load of cold and heat source to choose the cold and heat source program and cold and heat source selection calculation。 Finally, a variety of auxiliary equipment selection and model selection。