The automatic adjustment control method of hot water constant pressure control system setting

Abstract

The invention discloses an automatic setup adjustment and control method of a hot water constant pressure control system. The method comprises the following steps of: (1) state judgment, (2) information sampling state selection, (3) a systemic pressure judgment period, (4) a systemic pressure judgment interval, (5) a basic boundary condition of judgment, (6) a hot water constant pressure adjustment setup state, and (7) a hot water constant pressure setup pressure automatic adjustment value. The pressure of a system under a no water use condition is sampled; a system adjustment pressure setup value is optimized as 70% of a hot water pressure sampling value according to a relationship between a rotating speed and the pressure and an optimal operation pressure area (49-81% of a maximum pressure range) of the system; different water flow requirements of the system can be met; and the optimal operation area under a hot water supply condition can be met. The method avoids the situations thatthe system is in a critical constant pressure state all the time, the operation pressure is unstable, and a use effect is influenced.

Description

technical field [0001] The invention relates to an automatic adjustment control method for setting of a hot water constant pressure control system. Background technique [0002] When the water pump is working, there will be cavitation phenomenon. There are two main different situations as follows: [0003] Cavitation phenomenon: When the centrifugal pump is working, the vacuum pressure generated in the center of the impeller is too low, so that it is lower than the saturated vapor pressure of the liquid, and the sucked liquid vaporizes in a large amount in the vacuum area to generate bubbles. The liquid containing air bubbles condenses or ruptures rapidly after being squeezed into the high-pressure area. Due to the partial vacuum generated by the disappearance of the bubbles, the surrounding liquid flows to the center of the bubbles at a very high speed, which instantly produces a huge local impact force, causing impacts on the impeller and the pump casing, and damaging the...

AI Technical Summary

Problems solved by technology

[0021] According to the relationship between temperature and pressure in Table 1, it can be seen that with the change of temperature or pressure of hot water in the system, the effect of cavitation is different, and there is uncertainty in the change of temperature and pressure in the system, so the cavitation allowance is also Uncertain, it is more difficult to realize the constant pressure operation of the system in the hot water supply system that needs to achieve constant pressure water supply

Due to the influence of cavitation, the pressure set by the system may not be able to reach, which will cause the system users to use water, depending on the flow, the pressure will be different, which will affect the normal water use of users. When the cavitation is large, the water pump will reach the maximum. Under the condition of rated speed, the pressure set by the system still cannot be reached, which will make it impossible to judge whether the system is using water or no water, and the system will make a misjudgment, and it will not be possible to automatically enter the dormant shutdown state when the user stops using water, and the water pump will continue to run. After the water pump is running, the kinetic energy is converted into heat energy, and the water temperature in the pump will continue to rise. After a long time, the water will be too high and cause damage to the water pump.

When cavitation occurs, the hot water is pressurized. When the centrifugal water pump works at a constant pressure, the efficiency of the pump is affected, and it is difficult to reach the rated pressure set by the system. In addition, when the system has cavitation, if the system When there is no water, because the system cannot reach the set pressure, the system reaches the maximum speed through the speed adjustment, which not only increases the system noise, but also wastes energy, accelerates the aging of the system, and affects the life of the system

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