Method for controlling number of pumps, device for controlling number of pumps, pump system, heat source system, and program

Abstract

A method for controlling number of pumps includes a process of increasing or decreasing the number of operating pumps based on a flow rate of a heat medium that is forcibly fed to a load ( 40 ) by a plurality of pumps connected in parallel or a heat load required by the load and a frequency command value commanded to each pump in operation among the plurality of pumps.

1 - 11 . (canceled) 
     
     
         12 . A method for controlling number of pumps, comprising:
 a process of acquiring a number-of-pumps determination flow rate value indicating a flow rate of a heat medium forcibly fed to a load from a measurement value of a discharge flow rate by the pumps in operation among a plurality of pumps, and   a process of increasing or decreasing a number of operating pumps based on the flow rate of the heat medium that is forcibly fed to the load by the plurality of pumps connected in parallel or a heat load required by the load and a frequency command value commanded to each pump in operation among the plurality of pumps,   wherein, in the process of increasing or decreasing the number of operating pumps, the number of operating pumps is increased when the number-of-pumps determination flow rate value is equal to or larger than a predetermined threshold value Gα, and the frequency command value commanded to each pump is equal to or larger than a predetermined threshold value Fα, and the number of operating pumps is decreased when the number-of-pumps determination flow rate value is equal to or smaller than a predetermined threshold value Gβ, and the frequency command value commanded to each pump is equal to or smaller than a predetermined threshold value Fβ.   
     
     
         13 . A method for controlling number of pumps, comprising:
 a process of calculating a heat load required by a load, and   a process of increasing or decreasing a number of operating pumps based on a flow rate of a heat medium that is forcibly fed to the load by the plurality of pumps connected in parallel or the heat load required by the load and a frequency command value commanded to each pump in operation among the plurality of pumps,   wherein, in the process of increasing or decreasing the number of operating pumps, the number of operating pumps is increased when the heat load is equal to or larger than a predetermined threshold value Lα, and the frequency command value commanded to each pump is equal to or larger than a predetermined threshold value Fα, and the number of operating pumps is decreased when the heat load is equal to or smaller than a predetermined threshold value Lβ, and the frequency command value commanded to each pump is equal to or smaller than a predetermined threshold value Fβ.   
     
     
         14 . The method for controlling number of pumps according to  claim 12 ,
 wherein, in the process of increasing or decreasing the number of operating pumps, a pump head of the pump is further compared with an increase permission pump head serving as a threshold value for increasing the number of pumps or a decrease permission pump head serving as a threshold value for decreasing the number of pumps, the number of operating pumps is increased only when the increase permission pump head is smaller than the pump head, and the number of operating pumps is decreased only when the decrease permission pump head is larger than the pump head.   
     
     
         15 . The method for controlling number of pumps according to  claim 14 , further comprising:
 a process of obtaining the increase permission pump head by calculating the pump head when a frequency of the pump is operated at the predetermined threshold value Fβ from the pump head calculated based on the discharge flow rate of the pump after the number of operating pumps is increased and a predetermined correlation of the pump head for the discharge flow rate of the pump and obtaining the decrease permission pump head by calculating the pump head when the frequency of the pump is operated at the predetermined threshold value Fα from the pump head calculated based on the discharge flow rate of the pump after the number of operating pumps is decreased and the predetermined correlation.   
     
     
         16 . The method for controlling number of pumps according to  claim 12 , further comprising:
 a process of acquiring a frequency command value after the number of operating pumps is increased and a frequency command value after the number of operating pumps is decreased based on a predetermined correlation between the pump head and the discharge flow rate of the pump at a predetermined frequency of the pump in operation under a condition that the pump head after the number of operating pumps is increased or decreased to be equal to a current pump head,   wherein, in the process of increasing or decreasing the number of operating pumps, the number of operating pumps is further increased only when the frequency command value after the number of operating pumps is increased is larger than the threshold value Fβ, and the number of operating pumps is decreased only when the frequency command value after the number of operating pumps is decreased is smaller than the threshold value Fα.   
     
     
         17 . The method for controlling number of pumps according to  claim 12 , further comprising:
 a process of acquiring a pump efficiency after the number of operating pumps is increased, a pump efficiency after the number of operating pumps is decreased, and a current pump efficiency based on a predetermined correlation between the discharge flow rate and the pump efficiency at the predetermined frequency of the pump in operation,   wherein, in the process of increasing or decreasing the number of operating pumps, the number of operating pumps is further increased only when the pump efficiency after the number of operating pumps is increased is equal to or larger than the current pump efficiency, and the number of operating pumps is decreased only when the pump efficiency after the number of operating pumps is decreased is equal to or larger than the current pump efficiency.   
     
     
         18 . A device for controlling number of pumps, comprising:
 a number-of-pumps determination flow rate value acquiring unit configured to acquire a number-of-pumps determination flow rate value indicating a flow rate of a heat medium forcibly fed to a load from a measurement value of a discharge flow rate by the pumps in operation among a plurality of pumps, and   a number-of-pumps control unit configured to increase or decrease the number of operating pumps that are connected in parallel to forcibly feed the heat medium to the load based on the flow rate of the heat medium forcibly fed to the load or a heat load required by the load and a frequency command value commanded to each pump in operation among the plurality of pumps,   wherein, the number-of-pumps control unit is configured so that the number of operating pumps is increased when the number-of-pumps determination flow rate value is equal to or larger than a predetermined threshold value Gα, and the frequency command value commanded to each pump is equal to or larger than a predetermined threshold value Fα, and the number of operating pumps is decreased when the number-of-pumps determination flow rate value is equal to or smaller than a predetermined threshold value Gβ, and the frequency command value commanded to each pump is equal to or smaller than a predetermined threshold value Fβ.   
     
     
         19 . A pump system, comprising:
 a plurality of pumps connected in parallel; and   the device for controlling number of pumps according to  claim 18 ,   wherein the number of operating pumps is changed so that the pump head per pump and the flow rate measurement value are not changed.   
     
     
         20 . A heat source system, comprising:
 a load;   a plurality of heat source machines configured to forcibly feed a heat medium and connected in parallel;   a secondary pump configured to further forcibly feed the heat medium forcibly fed from the plurality of heat source machines connected in parallel to the load; and   the device for controlling number of pumps according to  claim 18 .   
     
     
         21 . A non-transitory computer-readable storage medium storing a program causing a computer of a device for controlling number of pumps to function as:
 a number-of-pumps determination flow rate value acquiring unit configured to acquire a number-of-pumps determination flow rate value indicating a flow rate of a heat medium forcibly fed to a load from a measurement value of a discharge flow rate by the pumps in operation among a plurality of pumps, and   a unit configured to increase or decrease the number of operating pumps based on the flow rate of the heat medium that is forcibly fed to the load by the plurality of pumps connected in parallel or a heat load required by the load and a frequency command value commanded to each pump in operation among the plurality of pumps   wherein, the unit configured to increase or decrease the number of operating pumps is configured so that the number of operating pumps is increased when the number-of-pumps determination flow rate value is equal to or larger than a predetermined threshold value Gα, and the frequency command value commanded to each pump is equal to or larger than a predetermined threshold value Fα, and the number of operating pumps is decreased when the number-of-pumps determination flow rate value is equal to or smaller than a predetermined threshold value Gβ, and the frequency command value commanded to each pump is equal to or smaller than a predetermined threshold value Fβ.   
     
     
         22 . The method for controlling number of pumps according to  claim 13 ,
 wherein, in the process of increasing or decreasing the number of operating pumps, a pump head of the pump is further compared with an increase permission pump head serving as a threshold value for increasing the number of pumps or a decrease permission pump head serving as a threshold value for decreasing the number of pumps, the number of operating pumps is increased only when the increase permission pump head is smaller than the pump head, and the number of operating pumps is decreased only when the decrease permission pump head is larger than the pump head.   
     
     
         23 . The method for controlling number of pumps according to  claim 22 , further comprising:
 a process of obtaining the increase permission pump head by calculating the pump head when a frequency of the pump is operated at the predetermined threshold value Fβ from the pump head calculated based on the discharge flow rate of the pump after the number of operating pumps is increased and a predetermined correlation of the pump head for the discharge flow rate of the pump and obtaining the decrease permission pump head by calculating the pump head when the frequency of the pump is operated at the predetermined threshold value Fα from the pump head calculated based on the discharge flow rate of the pump after the number of operating pumps is decreased and the predetermined correlation.   
     
     
         24 . The method for controlling number of pumps according to  claim 13 , further comprising:
 a process of acquiring a frequency command value after the number of operating pumps is increased and a frequency command value after the number of operating pumps is decreased based on a predetermined correlation between the pump head and the discharge flow rate of the pump at a predetermined frequency of the pump in operation under a condition that the pump head after the number of operating pumps is increased or decreased to be equal to a current pump head,   wherein, in the process of increasing or decreasing the number of operating pumps, the number of operating pumps is further increased only when the frequency command value after the number of operating pumps is increased is larger than the threshold value Fβ, and the number of operating pumps is decreased only when the frequency command value after the number of operating pumps is decreased is smaller than the threshold value Fα.   
     
     
         25 . The method for controlling number of pumps according to  claim 13 , further comprising:
 a process of acquiring a pump efficiency after the number of operating pumps is increased, a pump efficiency after the number of operating pumps is decreased, and a current pump efficiency based on a predetermined correlation between the discharge flow rate and the pump efficiency at the predetermined frequency of the pump in operation,   wherein, in the process of increasing or decreasing the number of operating pumps, the number of operating pumps is further increased only when the pump efficiency after the number of operating pumps is increased is equal to or larger than the current pump efficiency, and the number of operating pumps is decreased only when the pump efficiency after the number of operating pumps is decreased is equal to or larger than the current pump efficiency.