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CN-122015294-A - Water heater water pump rotating speed control method, device and system

CN122015294ACN 122015294 ACN122015294 ACN 122015294ACN-122015294-A

Abstract

The application provides a water pump rotating speed control method, device and system for a water heater, and relates to the technical field of water heater control. The method is applied to a control main board, and comprises the steps of acquiring current water pump outlet pressure and current water pump rotating speed in real time after the water pump is started, reducing the current water pump rotating speed if the current water pump outlet pressure is lower than the current water pressure limit which corresponds to the current water pump rotating speed and generates cavitation noise until the latest current water pump outlet pressure is not lower than the current water pressure limit which corresponds to the latest current water pump rotating speed and generates cavitation noise, wherein the corresponding relation between the water pressure limit and the water pump rotating speed is positive correlation, and the change speed of the water pump outlet pressure along with the water pump rotating speed is smaller than the change speed of the water pressure limit along with the water pump rotating speed. The application can effectively reduce noise and cavitation when the water pressure suddenly drops in the water use peak period of the user.

Inventors

  • MA JIAYIN

Assignees

  • 广东万和新电气股份有限公司

Dates

Publication Date
20260512
Application Date
20260317

Claims (10)

  1. 1. The water pump rotating speed control method for the water heater is characterized by being applied to a control main board, and comprises the following steps: After the water pump is started, the current outlet pressure of the water pump and the current rotation speed of the water pump are obtained in real time; If the current water pump outlet pressure is lower than the current water pump rotation speed corresponding to the current water pump rotation speed which generates cavitation noise, reducing the current water pump rotation speed until the latest current water pump outlet pressure is not lower than the current water pump rotation speed corresponding to the latest current water pump rotation speed which generates cavitation noise; The corresponding relation between the lower water pressure limit and the rotation speed of the water pump is positive correlation, and the change speed of the outlet pressure of the water pump along with the rotation speed of the water pump is smaller than that of the lower water pressure limit along with the rotation speed of the water pump.
  2. 2. The method according to claim 1, wherein the method further comprises: Judging whether the current water pump outlet pressure is higher than a pressure recovery threshold value or not if the current water pump outlet pressure is not lower than a current water pressure limit which corresponds to the current water pump rotating speed and generates cavitation noise, wherein the pressure recovery threshold value is a preset pressure increment added to the current water pressure limit or a preset multiple of the current water pressure limit, and the preset multiple is larger than 1; If not, maintaining the current water pump rotating speed; and if so, adjusting the rotation speed of the water pump according to the magnitude relation between the current water pump outlet pressure and the set pressure interval.
  3. 3. The method according to claim 2, wherein the step of adjusting the rotational speed of the water pump according to the magnitude relation between the current water pump outlet pressure and the set pressure interval comprises: The method comprises the steps of setting the current water pump outlet pressure, setting the current water pump rotation speed, and maintaining the current water pump rotation speed if the current water pump outlet pressure is smaller than the lower limit value of the pressure range, and setting the current water pump rotation speed if the current water pump outlet pressure is smaller than the lower limit value of the pressure range.
  4. 4. The method of claim 2, wherein the set pressure interval has a lower limit of a specified pressure minus a first set pressure and an upper limit of the specified pressure plus a second set pressure; when the current working mode is a water pressurizing mode, the specified pressure is a third set pressure; and when the current working mode is not the water pressurizing mode, the specified pressure is the minimum value of a preset water pressure upper limit and a first pressure value, wherein the first pressure value is the sum of the starting water pressure and a fourth set pressure.
  5. 5. The method of claim 2, further comprising, prior to the step of adjusting the rotational speed of the water pump, based on the magnitude relationship between the current water pump outlet pressure and the set pressure interval: acquiring the current water pump power; Judging whether the current water pump power is smaller than or equal to a power threshold value; if not, reducing the current rotation speed of the water pump; If yes, continuing to execute the step of adjusting the rotation speed of the water pump according to the magnitude relation between the current outlet pressure of the water pump and the set pressure interval.
  6. 6. The method of claim 2, further comprising, prior to the step of adjusting the rotational speed of the water pump, based on the magnitude relationship between the current water pump outlet pressure and the set pressure interval: Acquiring the current demand load of the water heater; judging whether the current demand load is smaller than or equal to the maximum load; if not, reducing the current rotation speed of the water pump; If the current demand load is not less than or equal to a preset load, maintaining the current water pump rotating speed; and if the current demand load is smaller than or equal to a preset load, continuing to execute the step of adjusting the rotation speed of the water pump according to the magnitude relation between the current outlet pressure of the water pump and the set pressure interval.
  7. 7. The method of claim 6, further comprising, prior to the step of adjusting the rotational speed of the water pump, based on a magnitude relationship between the current water pump outlet pressure and a set pressure interval: judging whether the current water pump rotation speed reaches the maximum rotation speed or not; If yes, maintaining the current water pump rotating speed; if not, continuing to execute the step of adjusting the rotation speed of the water pump according to the magnitude relation between the current outlet pressure of the water pump and the set pressure interval.
  8. 8. The method of claim 1, wherein the water pump speed adjustment is performed in a stepwise adjustment or a continuous adjustment.
  9. 9. The water pump rotating speed control device for the water heater is characterized by being applied to a control main board, and comprises: the pressure rotating speed acquisition module is used for acquiring the current outlet pressure of the water pump and the current rotating speed of the water pump in real time after the water pump is started; the rotating speed adjusting module is used for reducing the current water pump rotating speed until the latest current water pump outlet pressure is not lower than the current water pump rotating speed corresponding to the current water pressure limit generating cavitation noise if the current water pump outlet pressure is lower than the current water pressure limit generating cavitation noise corresponding to the latest current water pump rotating speed; The corresponding relation between the lower water pressure limit and the rotation speed of the water pump is positive correlation, and the change speed of the outlet pressure of the water pump along with the rotation speed of the water pump is smaller than that of the lower water pressure limit along with the rotation speed of the water pump.
  10. 10. The water pump rotating speed control system of the water heater is characterized by comprising a water pump, a water pressure sensor and a control main board, wherein the water pump is arranged in the water heater, the water pressure sensor is arranged at an outlet of the water pump and is in communication connection with the control main board, the water pump is in communication connection with the control main board, the water pressure sensor is used for detecting the current outlet pressure of the water pump in real time after the water pump is started and sending the current outlet pressure of the water pump to the control main board, and the control main board is used for executing the method according to any one of claims 1-8.

Description

Water heater water pump rotating speed control method, device and system Technical Field The application relates to the technical field of water heater control, in particular to a water pump rotating speed control method, device and system of a water heater. Background In order to realize the zero cold water preheating function or the supercharging function, the existing gas water heater is internally provided with a water pump, and the water pump runs, so that hot water can be circulated to a water consumption point in advance, or enough flow is ensured during normal water consumption. When the water pump is running, the water heater typically controls the water pump to run at a fixed maximum power. In the water peak period, when the water pressure of a user fluctuates, the water pressure suddenly drops, and when the water pump operates at the maximum power, the inlet pressure of the water pump is lower than the saturated vapor pressure, bubbles are easy to generate and are broken, and obvious abnormal noise is formed. Disclosure of Invention The first technical problem to be solved by the invention is to provide a water pump rotating speed control method for a water heater, which can effectively reduce noise and cavitation. The second technical problem to be solved by the invention is to provide a water pump rotating speed control device of a water heater, which can effectively reduce noise and cavitation. The third technical problem to be solved by the invention is to provide a water pump rotating speed control system of a water heater, which can effectively reduce noise and cavitation. The first technical problem is solved by the following technical scheme: A water pump rotating speed control method of a water heater is applied to a control main board, and comprises the steps of acquiring current water pump outlet pressure and current water pump rotating speed in real time after the water pump is started, reducing the current water pump rotating speed until the latest current water pump outlet pressure is not lower than the current water pump rotating speed corresponding to the latest current water pump rotating speed and generating cavitation noise if the current water pump outlet pressure is lower than the current water pump rotating speed corresponding to the current water pump rotating speed, wherein the corresponding relation between the water pressure lower limit and the water pump rotating speed is positive correlation, and the change speed of the water pump outlet pressure along with the water pump rotating speed is smaller than the change speed of the water pressure lower limit along with the water pump rotating speed. Compared with the background technology, the water pump rotating speed control method for the water heater has the advantages that after the water pump is started, the current water pump outlet pressure and the current water pump rotating speed are obtained in real time, the current water pressure limit corresponding to cavitation noise can be determined through the current water pump rotating speed, then whether the water pump generates noise and cavitation phenomenon is judged and identified through judgment of the current water pump outlet pressure and the current water pressure limit, when the current water pump outlet pressure is lower than the current water pressure limit, the water pump is likely to generate noise and cavitation phenomenon, and because the corresponding relation between the water pressure limit and the water pump rotating speed is positive correlation, both the water pump outlet pressure and the water pressure limit can be reduced through reducing the current water pump rotating speed, the change speed of the water pump outlet pressure along with the water pump rotating speed is smaller than the change speed of the water pressure lower limit along with the water pump rotating speed, and in the process of reducing the current water pump rotating speed, the latest current water pump outlet pressure is not lower than the current water pressure limit corresponding to cavitation noise generation of the latest current water pump rotating speed, and therefore noise and cavitation phenomenon generation can be effectively reduced. In one embodiment, the method further comprises judging whether the current water pump outlet pressure is higher than a pressure recovery threshold value or not if the current water pump outlet pressure is not lower than a current water pump rotation speed corresponding to a current water pressure limit generating cavitation noise, wherein the pressure recovery threshold value is a preset pressure increment added to the current water pressure limit or a preset multiple of the current water pressure limit, the preset multiple is larger than 1, if not, the current water pump rotation speed is maintained, and if so, water pump rotation speed adjustment is carried out according to the magnitude relation between the current water pump outlet p