There are many classification methods for air conditioning water systems. According to the layout and working principle of the pipelines, they can generally be summarized into the following main types:
According to the principle, it can be divided into: closed cycle and open cycle;
According to the number of supply and return water pipes It is divided into: two-pipe, three-pipe and four-pipe;
is divided into: same program and different program according to the flow relationship of supply and return water in the pipeline;
can be divided into: fixed water volume and variable water volume according to the adjustment method.
1, closed circulation system
definition: a system in which the piping system is not in contact with the atmosphere, and an expansion tank is installed at the highest point of the system and has exhaust and drainage devices. When the air conditioning system uses fan coil , inducer and water-cooled surface cooler for cooling, the cold water system should use a closed system. Closed systems should be used in high-rise buildings.
2. Open circulation system
definition: There is a water storage tank (or pool) between the pipelines to vent to the atmosphere. A system in which the pipes are connected to the atmosphere when returning water by gravity. When the air conditioning system uses a spray chamber to cool the air, an open system should be used.
3. Two-pipe water system
definition: The cooling system and the heating system use the same water supply pipe and return pipe , only a system with two water pipes, one supply and one return.
4, three-pipe water system
definition: three water pipes are set up: cooling pipeline, heating pipeline, and heat exchange equipment pipeline; the cold water and hot water return pipes are shared.
5, four-pipe water system
definition: The cold water and hot water system has completely separate water supply pipes and return pipes, which can meet the requirements of a high-quality air-conditioned environment.
6, the same programming system
definition: the length of the pipes passing through each parallel loop is basically the same, and the resistance is similar; if the resistance loss through each meter of pipeline is close to the same, the resistance of the pipe network can be balanced without adjustment. The advantages of the same program system are that the hydraulic stability of the system is good, the water distribution between each equipment is balanced, and the adjustment is convenient.
7, different program system
definition: the pipe lengths passing through each parallel loop are different, and the resistance of the pipelines is different; the corresponding regulating valve needs to be added to each parallel pipe network to adjust the balance of the water network. Advantages of the offset system: The offset system is simple, consumes less pipe materials, and is less difficult to construct.
8, fixed water volume system
definition: the circulating water volume in the system is a fixed value, and the supply and return water temperatures are changed to adapt to changes in the room load. Each air-conditioning terminal device of this system is regulated by an electric three-way regulating valve controlled by the thermostat located in the air-conditioned room.
9, variable water volume system
definition: a system that keeps the water supply temperature within a certain range and changes the water supply volume when the load changes. Each air-conditioning terminal device of this system is adjusted by the electric two-way regulating valve controlled by the thermostat located in the air-conditioned room.
