(1) The chilled water supply and return pipes of central air conditioners are generally equipped with pressure differential bypass valves.
(2) The principle is to sense the water pressure at both ends of the supply and return water through the pressure difference controller, and then calculate the difference based on the measured pressure, and then the pressure difference controller calculates the difference based on the calculated pressure. The difference is compared with the preset value to determine the output mode to control the valve to increase or decrease the opening, thereby adjusting the water volume to achieve the purpose of balancing the water pressure of the host system.
(3) Design basis for the size of the bypass pipe: The empirical value of the size of the bypass pipe is calculated as 1/3 of the main pipe, rounded up to the commonly used pipe diameter.
Extended information:
The self-operated self-operated differential pressure control valve is an alternative product to the electric differential pressure control valve. Its advantage is that it does not require external power and relies on the pressure of the system itself, which effectively improves the operating safety factor. It is safer and more reliable than the traditional electric differential pressure control valve, and solves the problem of the electric differential pressure control valve's reliance on electricity and circuit problems that may cause the unit The probability of damage is reduced, and the self-operated self-pressure difference control valve is easy to install and saves costs.
The purpose of the self-operated self-operated differential pressure control valve:
The self-operated self-operated differential pressure control valve is used for the protection of cold (heat) source units. Installed on the bypass pipe between the collector and the water distributor. When the user side is partially operating or operating with variable transport volume, the system flow becomes smaller, resulting in an increase in the pressure difference. When the pressure difference exceeds the set value, the valve automatically opens, and the partial The flow rate passes here to ensure that the unit flow rate is not less than the limit.
The self-operated self-pressure differential control valve is used in central heating systems to ensure that the cooling equipment in a certain area is not overpressured or empty. For example, if a system has a large height difference and no system is divided into high and low zones, if the pressure is set at the high level, the heat dissipation equipment at the low level may burst; if the pressure is set at the low level, the heat dissipation equipment at the high level will be emptied.
In this case, if the heat source is low, you can add a booster pump to the branch water pipe entering the high zone, and add a pressure difference valve to the return pipe to increase the pressure in the high zone and then reduce it to the return water in the low zone. Pressure; if the heat source is at a high place, the water supply pipe in the low area can be installed with a pressure difference valve, and a booster pump can be added to the return water, so that the circulating water with reduced pressure through the valve can return to the system.
Baidu Encyclopedia ?——Central air conditioning (air conditioning system)