The diaphragm air pressure tank is an energy storage device composed of a steel shell and a rubber diaphragm liner. The rubber diaphragm completely separates the water chamber and the air chamber. When the pressure of the outside is filled into the liner of the diaphragm air pressure water tank, it is sealed The air in the tank is compressed. According to Boyle’s law of gas, the volume of the compressed gas becomes smaller and the pressure rises to store energy. The expansion of the compressed gas can force the water in the rubber diaphragm out of the tank.
1Scope of application:edit
Diaphragm air pressure tanks are widely used in central air conditioning circulating water stabilization, distilled water supply expansion system, heating system circulating water replenishment stabilization, fire water supply system replenishment stabilization, frequency conversion water stabilization, boiler water replenishment, air pressure water supply and other occasions.
2Performance characteristics:edit
1. The internal diaphragm structure of the tank ensures that the water does not contact the tank wall, so there is no rust inside the tank wall, no condensation on the outside, and the service life is greatly extended.
2. The rubber diaphragm can relax more than 200,000 times, and can be used for a long time after being inflated.
3. It can effectively smooth the pressure fluctuations in the water system and reduce the start and stop frequency of the water pump.
4. The diaphragm is a food-grade natural rubber diaphragm that can be used in drinking water systems.
3Selection calculation:edit
We know that whether it is a differential pressure type or a variable frequency water supply unit, a diaphragm air pressure tank must be selected to solve the phenomenon of frequent restarts of the water pump. So, how to choose the volume of the pressure tank and the pressure level of the pressure tank? The volume of the pressure tank must be selected on a basis, otherwise it will still not solve the problem of frequent pump restarts. The capacity of the pressure tank must be selected according to the pump flow, head and start frequency to select the pressure level of the pressure tank.
1. Volume calculation
Generally, the relationship between the number of starts per hour and the power of the pump is as follows:
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Motor power (Kw)
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Below 5.5Kw
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5.5-7.5Kw
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7.5-22Kw
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22-55Kw
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Number of starts (times/hour)
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30
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20
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12
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8
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1. The effective volume Vesp calculation formula is as follows:
Vesp=16.5×Q/n, where Q is the flow rate of the pump and n is the number of starts per hour
2. Calculate the effective capacity coefficient according to the start and stop characteristics of the pump
Z=(Pi+1.033)/(Pf+1.033)
Among them, Z is the effective flow coefficient, that is, the ratio of the effective capacity utilization rate of the pressure tank under the condition of the known starting and stopping pressure of the water pump.
Pi is the starting pressure of the water pump = actual head + pipeline loss + pressure required by the system
Pf is the stop pressure of the pump = generally Pi+(1-2)kg/cm2
3. Calculate the actual capacity of the pressure tank according to Vesp and Z
Vt=Vesp/Z
Two, pressure level selection
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The pressure level of the pressure tank used for general domestic water supply is divided into 1.0Mpa, 1.6Mpa and 2.5Mpa
According to the pressure range value of the actually selected water pump, the pressure tank is correctly matched, and the pressure level of the pressure tank must be greater than the pressure value of the water pump.
