A Calculation Method of Theoretical Water Inflow of Secondary Water Supply Tank

Abstract

The invention discloses a method for calculating the theoretical water inflow of a secondary water supply tank. The average outflow and maximum outflow of water in different time periods on working days or rest days; 3. Calculate the theoretical water retention of the water tank at the beginning of different time periods in a working day or rest day; 4. On working days or rest days At the beginning of each time period of a day, calculate the theoretical water inflow of the water tank in different time periods of the day on working days or rest days based on the theoretical water retention, real-time water retention and the maximum water storage capacity of the water tank. The invention can accurately control the residence time of the tap water in the water tank under the premise of meeting the requirement of water use, and effectively reduce the risk of exceeding the standard of microbial indicators caused by the excessive residence time of the tap water in the water tank.

Description

technical field [0001] The invention relates to the field of secondary water supply of urban water supply pipe network systems, in particular to a method for calculating the theoretical inflow of water in a secondary water supply tank. Background technique [0002] Secondary water supply refers to the form of water supply in which urban public water supply is stored, pressurized, and then supplied to users through pipelines. The drinking water (hereinafter referred to as tap water) in the secondary water supply and storage equipment (hereinafter referred to as the water tank) is extracted by a water pump or automatically flows in from the urban water supply pipe network system. The inlet flow of the water tank refers to the flow of tap water at the inlet of the water tank at a certain moment; the outlet flow of the water tank refers to the flow of tap water at the outlet of the water tank at a certain moment; the inflow of the water tank refers to the volume of tap water flo...

AI Technical Summary

Problems solved by technology

The most common problem of secondary water supply is that the tap water stays in the water tank for too long, which causes the concentration of residual chlorine in the tap water of the tank to decay to a very low level, which cannot effectively kill the microorganisms in the water, causing the microorganisms in the tap water in the tank to rapidly Microbiological indicators exceeding the standard due to growth

[0005] 1) This technology does not distinguish between working days and rest days when statistically analyzing the characteristics of water use. In practice, the water use characteristics of working days and rest days are completely different. For some places, such as schools and office buildings, the Water consumption is much higher than that on rest days, especially during the time period of 6:00-20:00. The average water consumption on working days is several times (3-5 times) the average water consumption on rest days. Statistical analysis is carried out on daily and working days. If the obtained average water consumption is used for water supply control on rest days, it will be obviously too large, which will lead to excessive water storage and completely lose the effect of controlling water supply. Using the resulting average water consumption for water supply control The water supply control on weekdays is relatively small, which may easily lead to insufficient water storage

[0006] 2) The final calculation result of this technology is the inlet flow. It is intended to control the residence time of tap water in the water tank by controlling the inlet flow. However, it is difficult to accurately control the inlet flow in practice, which limits the practical application of this technology.

[0007] 3) This technology does not consider the problem of the invalid volume of the water tank. Since some deposits will gradually remain at the bottom of the water tank, in order to prevent these deposits from flowing out to the user with the outlet pipe of the water tank, the outlet pipe is deliberately closed when installing the outlet pipe of the water tank. Raise it to a certain height from the bottom of the water tank. Usually, the vertical distance between the lower edge of the water outlet pipe and the bottom of the water tank is 10-20cm. Therefore, the water stored below the lower edge of the water outlet pipe of the water tank will not be able to flow out with the water outlet pipe. This part cannot be used. dead volume

In addition, for a water tank that uses a water pump to control the water outlet, if the outlet pipe is empty, the water pump will be damaged due to dry pumping. In order to prevent the outlet pipe from being empty, the liquid level should not be lower than the upper edge of the outlet pipe. In this case, the invalid volume will be larger. However, this technology does not take into account the ineffective volume of the water tank when calculating the theoretical water retention. According to this control of water supply, there will be a technical problem that the water storage is insufficient to meet the actual water demand.

[0008] 4) Each water tank is designed with an overflow pipe. The height between the overflow pipe and the bottom of the water tank is the maximum liquid level of the water tank. When the liquid level of the water tank reaches the maximum liquid level, if you continue to add water, the tap water will It will flow out from the overflow pipe. This technology does not consider the treatment method when the liquid level of the water tank reaches the highest level when the water is supplied to the water tank, so once this happens, tap water will be wasted

[0009] 5) This technology adopts an average division of time periods, which loses the flexibility of water supply management. In practice, it is necessary to divide the time periods shorter during peak water consumption periods to ensure sufficient water storage. Also refer to the division rules of the time period as in the peak water consumption period, it will often happen that the water supply needs to be shut down within a short time after the water supply is started, and the frequent startup and shutdown of the water pump will reduce the service life of the pump

[0010] 6) This technology does not consider the processing method when data is missing when statistically calculating the characteristics of water use. In practice, data missing may occasionally occur, such as sudden power failure, cleaning of water tanks, equipment maintenance or equipment failure, etc. If there is data missing, it will still Using the data of this day to calculate the characteristics of water use, the calculation results will be inaccurate or even seriously distorted

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