Comparison Of Frequency Conversion Constant Pressure Water Supply And Non Negative Pressure Water Supply

Comparison of frequency conversion constant pressure water supply and non negative pressure water supply

1、 The difference between the two devices is mainly in the operation principle

The biggest difference seen from the appearance of variable frequency constant pressure water supply and non negative pressure water supply is that the frequency conversion constant pressure water supply needs to be equipped with a large water tank, and the non negative pressure water supply equipment only has a small steady flow tank.

1) Variable frequency constant pressure water supply needs water tank to store water. The water supply unit pumps water from the tank to supply water to the users.

2) There is no negative pressure water supply equipment and no water tank. The water supply system has a steady flow tank, which can store a small amount of water.

In the equipment selection, the pressure calculation of non negative pressure equipment needs to subtract the water pressure of tap water, so the pump selection head is lower. In operation, the low-level water supply, no negative pressure equipment, can make use of the water supply network pressure water supply, no need to start the pump.

However, no matter what the situation is, the constant voltage frequency conversion equipment needs to start the water pump to supply water. In case of water cut-off, no negative pressure equipment will stop water supply. Frequency conversion constant pressure water supply can effectively provide 2 days according to the specification because there is water tank for water storage.

2、 The cost of use and operation is different

The cost of variable frequency constant pressure water supply equipment is lower than that of non negative pressure water supply equipment, but the later maintenance cost of frequency conversion constant pressure water supply equipment is high, such as cleaning water tank.

In terms of use, there are also differences in the following aspects:

1. Health. Frequency conversion water supply equipment first needs to inject municipal water into the water tank for storage and then pump it out through the pump, resulting in secondary pollution; while the non negative pressure water supply equipment is directly connected with the municipal pipe network, completely isolated from the external environment, without secondary pollution.

2. Energy saving. Frequency conversion water supply completely wastes the pressure of municipal pipe network. The non negative pressure water supply is directly connected to the municipal pipeline, and the original pressure of municipal pipe network is used to pressurize water supply.

3. Floor area. Frequency conversion water supply equipment should be equipped with water tank according to the number of users, occupying a large area, while the non negative pressure water supply equipment has high integration and saves land.

3、 Differences in pipe network stability

In terms of stability, the two kinds of equipment have their own advantages and disadvantages. According to these two situations, the first case is that the municipal pipe network stops water, and the users who use frequency conversion water supply equipment can continue to use the water in the water tank, while the users without negative pressure water supply equipment directly have no water available. The second case is power failure. If there is a power failure, users using frequency conversion water supply equipment will have no water available, while users using non negative pressure water supply equipment can rely on the original pressure of municipal pipe network, and the water supply of low floor users will not be affected.

Summary

• 1. When the municipal water supply pressure is stable and the water quantity is sufficient, the non negative pressure variable frequency water supply can give full play to its advantages, and it is superior to the ordinary frequency conversion constant pressure water supply in the energy saving effect; the equipment cost is also lower than the ordinary frequency conversion constant pressure water supply.
  

• 2.When the pressure of municipal water supply is unstable and the water quantity is insufficient, the water tank needs to be added as the standby water source for the non negative pressure variable frequency water supply equipment, and the equipment cost is higher than that of the ordinary frequency conversion constant pressure water supply equipment; the energy saving effect is not obvious。