JP2007297936A - Water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the situation where that a plurality of pumps constructing a system reaches the end of their service life simultaneously when the operation time of each pump is equalized in a water supply system using the plurality of pumps. <P>SOLUTION: In the water supply device provided with the plurality of pumps and a control device controlling operation of the pumps, accumulated operation time of each pump is stored and a pump to be operated at next time is selected to make accumulated operation time of each pump in a predetermined staircase shape. Accumulated operation time of each pump is stored and a plurality of pump groups comprising one or a plurality of pumps are established, and a pump to be operated at next time is selected to make average accumulated operation time of each pump group in a predetermined staircase shape. A process selecting the pump to be operated at next time to make accumulated operation time in the predetermined staircase shape is performed a period Tb which is equal to or shorter than a period Ta in the fixed period Ta. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a system for supplying water using a plurality of pumps.

Conventional technology

More and more systems that use multiple pumps to supply water have been used. Many of these are equipped with a small flow rate stop function that stops the pump when there is no load, and adopts a system that switches the pump to be operated next time each time the pump is stopped. The purpose of this is to prevent the water in the stop pump from being spoiled and to equalize the operating time of each pump, thereby prolonging the entire life of the system. In addition, as disclosed in JP 2000-45982, a system for controlling the operation time of each pump to be uniform has been proposed.
JP2000-45982

  In a water supply system using a plurality of pumps, in order to increase the reliability of the system, a plurality of pumps are used for the purpose of continuing water supply even if any of the pumps fails. The conventional technology aims to extend the life of the entire system by equalizing the operation time of each pump, but in this case, there is a risk that multiple pumps constituting the system will reach the end of their life simultaneously. .

  Therefore, in the present invention, in a water supply apparatus including a plurality of pumps as illustrated in FIG. 1 and a control device that controls the operation of the pumps, the accumulated operation time of each pump is stored, and the accumulated operation time of each pump is stored. By controlling the operation of each pump so that it is distributed in a staircase pattern based on the accumulated operation time distribution command as shown in FIG. 2, the period until the life of each pump is shifted, and the reliability of the entire system It is intended to improve the performance.

  In addition, the present invention provides a water supply apparatus having a plurality of pumps and a control device that controls the operation of the pumps, stores an accumulated operation time of each pump, and includes a pump group composed of one or a plurality of pumps. By setting a plurality of pumps and selecting the pump to be operated next time so that the average accumulated operation time of each pump group has a predetermined stepwise distribution, it is intended to achieve the same purpose as described in the previous section It is.

  For example, in a system that uses four pumps with components that will reach the design life in 10000 hours, when the first pump reaches 10000 hours, the operation time of the other pumps is 9000 hours, 8000 hours, 7000 hours, respectively. If the time can be adjusted, a plurality of pumps will not have the design life at the same time. Further, when the number of pumps in the system is large, it is also effective to configure a group for each of a plurality of pumps and distribute the accumulated operation time for each group as shown in FIG.

  When the pump operation control method according to the present invention is used, the lifetime of each pump constituting the pump system can be shifted in stages, and the reliability of the entire system can be improved. Furthermore, by adjusting the operating time interval between each pump, it is possible to set the period until the pump reaches the design life, which is effective for planning the time for equipment repair, and in stages over multiple years. Since it is possible to refurbish, it is also effective in terms of renovation budget procurement.

  An embodiment in the system having four pumps shown in FIG. 1 is shown below. First, the basic operation will be described. While the pump is stopped, the pressure is maintained by the pressure tank. When water is used and the discharge pressure drops, one pump is started. When the amount of water used increases and one pump runs out of water, it starts following the next pump. If the amount of water used is reduced and the flow rate is sufficient even if one pump is stopped, one pump is stopped. In this way, water is supplied while increasing or decreasing the simultaneous operation pump according to the amount of water used. If the amount of water used is reduced and a small flow rate is detected during operation with one pump, the last operating pump stops and the system enters a standby state.

In a general system, the starting priority of the pump is controlled to be the lowest when the pump is stopped. Thereby, the operation time of each pump is kept relatively uniform. In the system invented this time, the pump to be operated next time is managed by the next operation pump management array shown in FIG.
The activation priority becomes higher as it goes higher in the array.

  A basic operation related to the arrangement will be described. When the discharge pressure drops and the pump activation request is established, the activation priority is 1st = the next pump in the next operation pump management array is activated. At this time, the contents of the array are shifted forward one by one, and the pump having the second startup priority becomes the next startup priority first. Note that operating pumps are not stored in this array. When the pump is stopped, the stopped pump is added at the end of this array.

  The processing of the present invention will be described below. In the present invention, when a pump is added to the next operation pump management matrix due to a pump stop or the like, the next operation pump management array is rearranged according to the flow shown in FIG. Adjust based on the distribution command.

  The above process will be described in detail. First, in STEP1, for all pumps stored in the next-running pump management matrix, the total operation time T1 of the reference unit (here, No. 1) × the ratio Rn of the own unit and the integration of the own unit The difference ΔTn from the operation time Tn is calculated by ΔTn = T1 · Rn_Tn. Here, Tn is the accumulated operation time of each pump (subscript n is the pump number), and Rn is the ratio of the accumulated operation time of each pump based on the accumulated operation time distribution command to the reference unit.

  In STEP2, the next operation pump management matrix is rearranged in descending order of ΔTn. In STEP3, evaluate whether the reference unit is stored in the next-run pump management array. When the reference machine is stored in the next-time operation pump management array, the maximum value ΔTmax of ΔTn is compared with the reference time Ts (for example, 10 hours, 100 hours, etc.) in STEP4. When ΔTn ≦ Ts, the reference unit is stored at the head of the next operation pump management matrix in STEP5.

  By the above process, the accumulated operation time can be always changed according to the accumulated operation time distribution command. In addition, only with the above processing, a pump with a high priority is frequently operated, and a pump with a low priority is not operated so much. Therefore, there is a risk that water in the pump with a low priority is spoiled. Therefore, the adjustment of the operation time by the above processing is performed only for a certain period within a certain period, such as performing only a certain period within one day, for example, 18 hours, and normally performing pump rotation for the remaining period, for example, 6 hours. It is desirable to make it.

  As another embodiment of the present invention, the reference time to be compared with ΔTmax may be variable by setting instead of a fixed value, or may be a ratio (for example, 3%) with respect to the accumulated operation time of the reference unit. The example which rearranged the next operation | use pump arrangement | sequence according to the flow shown in FIG. 3 using the concrete numerical value was shown in FIG. 5, FIG.

  Since the present invention is configured as described above, the system for controlling the operation of a plurality of pumps in a place where the demand for water supply such as commercial buildings and high-rise apartments is constantly changing is in a good condition for pump operation and hygiene. This is effective for improving the reliability of the system when it is used continuously for a long period of time.

1 is a schematic view of a system having a plurality of pumps embodying the present invention. In the embodiment of FIG. 1, an accumulated operation time distribution command according to the present invention is shown. In the present invention, a processing step when a pump is added to the next-time operation pump management array is shown. The next operation pump management arrangement is shown. An example of transition of array storage is shown. Examples of various conditions relating to the processing of FIG. The integrated operation time distribution command in Example 2 of this announcement is shown.

Explanation of symbols

CTRL control
P1-P4 pump
PT pressure sensor
HD discharge joint piping
HS suction joint piping
AT pressure tank
GVT, GV11 to GV42 Gate valve
CV1 to CV4 check valve

Claims (3)

In a water supply apparatus having a plurality of pumps and a control device that controls the operation of the pumps, the accumulated operation time of each pump is stored so that the accumulated operation time of each pump has a predetermined stepwise distribution. A water supply device characterized by selecting a pump to be operated next time. In a water supply device that has a plurality of pumps and a control device that controls the operation of the pumps, memorize the accumulated operation time of each pump, set multiple pump groups consisting of one or more pumps, A water supply apparatus, wherein a pump to be operated next time is selected so that an average accumulated operation time of a pump group has a predetermined stepwise distribution. The process of selecting a pump to be operated next time so that the accumulated operation time has a preset distribution is performed only for Tb within a certain period Ta, which is a period equal to or less than Ta. The water supply apparatus as described in.

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