JP4925885B2 - Flow rate measurement method for piping system equipment - Google Patents

Description

  The present invention relates to a flow rate measurement method in a heat source supply system such as a district cooling and heating facility, and piping system equipment used as a heat source supply system such as a factory or a general building.

  Conventionally, a one-pump heat source facility 50 shown in FIG. 7 is known as a heat source supply system such as a district cooling and heating facility or a heat source supply system such as a factory or a general building.

  As shown in FIG. 7, the one-pump heat source facility 50 is heated or cooled by the first to third heat source devices 51 </ b> A to 51 </ b> C that heat or cool the heat medium and the heat source devices 51 </ b> A to 51 </ b> C. The heat medium pumps 52A to 52C for pumping the medium, the frequency controllers 53A to 53C for variably controlling the pump rotation frequency, and the heat medium pumps 52A to 52C are provided corresponding to the heat medium pumps 52A to 52C. After being fed to a feed header 54 that collects the pressure-fed heat medium and heat exchangers (air conditioners) 58, 58... Arranged in each part (room), the heat exchangers (air conditioners) 58, 58. A return header 55 that distributes the heat medium returned from the heat source devices 51A to 51C, a bypass 62 that connects the feed header 54 and the return header 55, a bypass valve 63 provided in the middle, and the feed F A differential pressure gauge 64 for measuring the pressure difference between the dust 54 and the return header 55, has a configuration in which a control device 60 for controlling and opening control of the bypass valve 63 of the heat source device 51A to 51C.

In such a one-pump heat source facility 50, the heat medium pumped by the heat medium pumps 52A to 52C is mixed in the feed header 54 and supplied to the heat exchanger 58 (air conditioner) via the main pipe 59 (outbound pipe line). Is done. And after heat exchange in the heat exchanger 58 (air conditioner), it returns to the return header 55 via a return water pipe, and is pumped and circulated again by the heat medium pumps 52A-52C (the following patent documents 1-3 etc.). reference).
JP 2000-18683 A JP 2004-184052 A JP 2004-245560 A

  However, in the conventional one-pump heat source equipment 50, as shown in FIG. 7, in order to measure the flow rate of the heat medium supplied from the feed header 54 to the heat exchanger side through the main pipe 59, the main pipe 59 is used. It was necessary to directly measure by installing a flow meter 65 such as an electromagnetic type, an ultrasonic type, or a Pitot tube type. At this time, when the flow meter 65 is installed in the existing heat source equipment, cutting or drilling of the main pipe 59 is required except for the ultrasonic flow meter. Further, with this processing operation, it is necessary to stop the supply of the heat medium to the main pipe 59 and to remove all the heat medium in the main pipe, which requires a lot of costs and days. For this reason, it is not easy to measure the flow rate supplied to the main pipe 59 in existing equipment with a flow meter other than the ultrasonic flow meter.

  In general, the flow meter has a higher equipment cost as the diameter of the pipe to be installed becomes larger. Therefore, there is a drawback that the equipment cost is increased to install the flow meter in a main pipe having a relatively large diameter. In addition, if a flow meter is installed in the main pipe with a large diameter and a large flow rate, depending on the type of flow meter, the resistance of the flow meter increases, and pump power is wasted. There were restrictions.

  Therefore, a main problem of the present invention is to provide a method for easily measuring a flow rate in a piping system facility without installing a flow meter in the main pipe.

In order to solve the above-mentioned problem, as the present invention according to claim 1, one or a plurality of heat source devices that cool or heat the heat medium, and a heat medium that is provided corresponding to each heat source device and that is cooled or heated are provided. A heat medium pump for pressure feeding, a frequency controller for variably controlling the pump rotation frequency, a feed header for collecting the heat medium from the heat source device, and a heat header from the feed header. The external load device to which the medium is supplied, the heat medium heat exchanged by the external load device is returned, and the return header distributed to each heat source device, the feed header portion or the vicinity thereof, and the return header portion or the vicinity thereof A bypass valve that adjusts the flow rate of the heat medium flowing through the bypass, and a control device that controls the operation of the heat medium pump and the opening degree of the bypass valve. In the piping system equipment of the system,
A bypass flow meter for measuring the flow rate of the heat medium flowing through the bypass, and a differential pressure meter for measuring a differential pressure between the feed header and the return header,
In the circulation system around the heat medium pump, the heat source device, the feed header, the bypass, and the return header, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each heat medium pump. Based on the above, an equation for calculating the pump flow rate Q using the pressure difference P between headers as a parameter at any pump operating frequency f is obtained,
By giving the calculation formula the differential pressure P between the headers measured by the differential pressure gauge and the operating frequency f of the heat medium pump, which is a set value for the frequency controller, the flow rate Q _{i of} each heat medium pump. together with respectively calculated by subtracting the flow rate Q _b of the from the total flow rate Q _P to the flow rate Q _i by summing the bypass flowmeter has measured the respective heating medium pump, a calculating means calculates the conveying flow of the heating medium A flow rate measuring method in a piping system facility is provided.

In the first aspect of the present invention, a bypass flow meter that measures the flow rate of the heat medium flowing through the bypass and a differential pressure meter that measures the differential pressure between the feed header and the return header are disposed, and the heat In the circulation system around the medium pump, heat source equipment, feed header, bypass, return header, for each heat medium pump, a relational expression between the header differential pressure P and the pump flow rate Q is obtained, and based on this relational expression, After obtaining a calculation formula of the pump flow rate Q using the pressure difference P between headers as a parameter at an arbitrary pump operating frequency f, the differential pressure P between headers measured by the differential pressure gauge is added to the calculation formula during actual operation. And the operating frequency f of the heat medium pump, which is a set value for the frequency controller, respectively, calculate the flow rate Q _i of each heat medium pump, and add the flow rate Q _i of each heat medium pump together. Whole stream Calculating a heat medium conveying flow by from Q _P subtracting the flow rate Q _b of the bypass flow meter was measured.

  Therefore, it is possible to measure the flow rate of the heat medium supplied from the feed header to the heat exchanger without installing a flow meter in the main pipe. Removal of the heating medium is not necessary. In addition, since the flow meter installed in the bypass only needs a relatively small diameter and a small flow rate, an inexpensive flow meter can be used, the equipment cost can be reduced, and resistance by the flow meter can be suppressed, so that it can contribute to energy saving of the pump. become.

  Further, in the case of the present invention, it is only necessary to install a flow meter in the bypass. Therefore, even in the case of post-construction, construction can be performed without closing the main pipe.

The present invention according to claim 2 includes a plurality of heat source devices that cool or heat the heat medium, a primary pump that is provided corresponding to each heat source device and that pumps the cooled or heated heat medium, and the heat source. A first feed header that collects the heat medium from the device, a plurality of secondary pumps that feed the heat medium from the first feed header, and a frequency that is provided corresponding to each secondary pump and that variably controls the pump rotation frequency A controller, a second feed header that collects the heat medium from the secondary pump, an external load device to which the heat medium is supplied from the second feed header, and a heat medium that has been heat-exchanged by the external load device are returned. A return header distributed to each heat source device, a first bypass and a first bypass valve connecting the first feed header and the second feed header, the first feed header section or its vicinity, and the return header section. Or nearby A second bypass connecting the bets, the piping system equipment 2 pump type and a control device for controlling the opening degree of the heat source device operating units control and operation control, and the first bypass valve of the secondary pump,
A bypass flow meter for measuring the flow rate of the heat medium flowing through the first bypass, and a differential pressure meter for measuring a differential pressure between the first feed header and the second feed header,
In advance, in the circulation system around the secondary pump, the second feed header, the first bypass, and the first feed header, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each secondary pump, Based on this relational expression, a formula for calculating the pump flow rate Q using the header differential pressure P as a parameter at any pump operating frequency f is obtained,
By giving the calculation formula the differential pressure P between the headers measured by the differential pressure gauge and the operating frequency f of the secondary pump which is a set value for the frequency controller, the flow rate Q _{i of} each secondary pump. together with respectively calculated by subtracting the flow rate Q _b of the flow rate Q _i from the total flow rate Q _P obtained by summing the bypass flowmeter has measured the respective secondary pump, and characterized by calculating the transport rate of the heating medium A flow rate measuring method in a piping system facility is provided.

  The invention according to claim 2 applies the present invention to a so-called secondary pump type heat source facility.

As a third aspect of the present invention, a plurality of pumps for pumping at least liquid are disposed between the first header and the second header, and a frequency for variably controlling the pump rotation frequency corresponding to each pump. A controller is provided, a bypass connecting the first header and the second header is provided, a bypass valve for adjusting a flow rate of the liquid flowing through the bypass is provided, and operation control of the pump and opening of the bypass valve are further provided. In the liquid transfer part of the piping system equipment provided with a control device that performs degree control,
A bypass flow meter for measuring a flow rate of liquid flowing through the bypass, and a differential pressure meter for measuring a differential pressure between the first header and the second header,
In the circulation system surrounding the first header, the heat medium pump, the second header and the bypass, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each heat medium pump in advance. Based on the above, a formula for calculating the pump flow rate Q using the inter-header differential pressure P as a parameter at any pump operating frequency f is obtained,
By giving the calculation formula the differential pressure P between the headers measured by the differential pressure gauge and the operating frequency f of the heat medium pump, which is a set value for the frequency controller, the flow rate Q _{i of} each heat medium pump. together with respectively calculated by subtracting the flow rate Q _b of the from the total flow rate Q _P to the flow rate Q _i by summing the bypass flowmeter has measured the respective heating medium pump, a calculating means calculates the conveying flow of the heating medium A flow rate measuring method in a piping system facility is provided.

  The invention according to claim 3 applies the present invention to piping system equipment in general.

  As described above in detail, according to the present invention, in the piping system facility, the flow rate can be easily measured without installing a flow meter in the main pipe.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[One-pump heat source equipment]
A 1-pump heat source facility 1A shown in FIG. 1 is provided corresponding to one or a plurality of heat source devices 2A to 2C for cooling or heating the heat medium and each heat source device 2A to 2C, and is cooled or heated. Heat medium pumps 3A to 3C for pressure-feeding the heat medium, frequency controllers 14A to 14C for variably controlling the pump rotation frequency, and heat medium from the heat source devices 2A to 2C. .., The external load devices 9, 9... To which the heat medium is supplied from the feed header 4, and the heat medium flowing through the external load device. The flow rate adjusting valve 11 for adjusting the flow rate and the heat medium exchanged by the external load devices 9, 9... Are returned, the return header 10 distributed to each of the heat source devices 2A to 2C, and the feed header portion 4 or its Near And the return header 10 or the vicinity thereof, the bypass valve 12 for adjusting the flow rate of the heat medium flowing through the bypass 13, the operation control of the heat medium pumps 3A to 3C, and the opening of the bypass valve 12 And a control device 8 that performs degree control.

Further, as measuring instruments, a bypass flow meter 17 for measuring the flow rate of the heat medium flowing through the bypass 13 and a differential pressure meter 16 for measuring the differential pressure between the feed header 4 and the return header 10 are provided. and are arranged header pressure difference P, based operation frequency f, the bypass flow rate Q _b, the flow rate calculation unit 20 for calculating a heat medium conveying flow.

[Measurement method of heat medium flow rate]
In measuring the heat medium flow rate, as shown in FIG. 2, in the circulation system around the heat medium pumps 3 </ b> A to 3 </ b> C, the heat source devices 2 </ b> A to 2 </ b> C, the feed header 4, the bypass 13, and the return header 10, For each of the medium pumps 3A to 3C, a relational expression between the header differential pressure P and the pump flow rate Q is obtained, and based on this relational expression, the header differential pressure P at any pump operating frequency f is used as a parameter. A calculation formula for the pump flow rate Qi is obtained and stored in the flow rate calculation device 20.

In the flow rate calculation device 20, the calculation formula includes the differential pressure P between the headers measured by the differential pressure gauge 16, and the operating frequency f of the heat medium pumps 3A to 3C, which is a set value for the frequency controller. by giving, to calculate the flow rate Q _i of each heat medium pump 3A~3C respectively, the flow rate Q _b of the from the total flow rate Q _P to the flow Q _i and the sum of respective heat transfer medium pump bypass flowmeter 17 is measured Is subtracted, the flow rate Q _M flowing through the main pipe 15 is calculated.

  The heat source devices 2A to 2C do not have to have the same specifications such as a flow rate range and a model, but are a plurality of the heat source devices having different specifications, and have different capacities corresponding to the specifications of the heat source devices. A heat medium pump may be provided.

This will be described in more detail below.
(Characteristic test of heat medium pump)
First, in the circulation system around the heat medium pumps 3A to 3C, the heat source devices 2A to 2C, the feed header 4, the bypass 13, and the return header 10, for each heat medium pump 3A to 3C, the inter-header differential pressure P and A relational expression with the pump flow rate Q is obtained.

  Specifically, in the actual machine, the supply path of the heat medium to the external load devices 9, 9... Is cut off by the manual valve 18 to form a flow path that circulates the bypass 13. While the 3C is operated at the rated frequency F (50 Hz or 60 Hz), the opening degree of the bypass valve 12 is changed (for example, 100% → 0% in an opening degree 10% step), and between the two headers by the differential pressure gauge 16 The differential pressure P and the flow rate Q of the heat medium flowing through the bypass 13 are measured by the bypass flow meter 17, and a relational expression between them is obtained experimentally. In FIG. 3, the PQ curve obtained by the said experiment is shown with the PQ curve in the case of a heat medium pump single-piece | unit. The PQ curve obtained by the experiment includes the heat source facilities 2A to 2C, the strainer, the check valve, the piping resistance, and the like.

The relational expression between the differential pressure P between the headers and the flow rate Q of the heat medium can be approximated as the following expression (1).

Since the above relational expression is based on the condition of operating at the rated frequency F (50 Hz or 60 Hz), the relational expression when the pump operating frequency is an arbitrary frequency f should be approximated as the following expression (2). Can do.

  By the way, the above method is an experimental method. If the PQ characteristic diagram of the pump, the PQ characteristic diagram of the heat source device, and the PQ characteristic diagram of the piping system are known in advance, ( By approximating the PQ characteristic diagram by (Equation (1)) by the PQ characteristic diagram of the pump (PQ characteristic diagram of the pump)-(Pressure drop by PQ characteristic diagram of heat source equipment and piping system) Can guide you.

(Calculation of flow rate Q _i of each heat medium pump)
In order to calculate the flow rate Q _i of each heat medium pump for the heat medium pumps 3A to 3C, the above equation (2) is solved for the flow rate Q of the heat medium, and is transformed into the following equation (3).

When pumps having different PQ characteristics exist in the same system, the operating frequency f _i , rated frequency F _{i of} each heat medium pump and the differential pressure P between the headers are calculated from the above equation (3) for all pumps. By substituting, the flow rate Q _i of each heat medium pump can be calculated.
(Calculation of the total flow rate _{Q P} of the refrigerant pump)
Next, from the flow rate Q _i of each heat medium pump calculated by the above equation (3), the total flow rate Q _P of the heat medium pump, that is, the flow rate of the heat medium flowing into the feed header 4 is calculated by the following equation (4). .

(Calculation of flow rate Q _M flowing through main pipe 15)
Finally, by correcting the flow rate _{Q b} of the bypass 13 from the total flow rate _{Q P,} determining the flow rate _{Q M} that is fed to the main pipe 15. That is, as shown in the following equation (5), the total flow rate Q _P that is pumped from the refrigerant pump 3A-3C, by subtracting the flow rate Q _b to be returned to the header 10 back through the bypass 13, the main pipe 15 The flow rate Q _M sent to the external load device 9, 9.

As described above, in the present invention, each heat is obtained from the set value of the operating frequency f to the frequency controller and the measured value of the differential pressure P between the headers by the differential pressure gauge 16 without installing a flow meter in the main pipe 15. each flow _{Q i} by medium pump 3A~3C can be calculated from their total flow rate _{Q P,} by subtracting the measured value _{Q b} of the bypass flow meter 17, it is possible to calculate the flow rate _{Q M} of easily main 15 .
(Verification test)
FIG. 4 shows a comparison between the calculated value of the flow rate of the main pipe 15 obtained by the flow rate measuring method according to the present invention and the actual value of the flow rate measured by installing a flow meter in the main pipe 15 under predetermined operating conditions. . As a result, the calculated value obtained by the flow measurement method according to the present invention accurately corresponds to the actual measurement value, and the effectiveness of the measurement method was proved.

[Two-pump heat source equipment]
A two-pump heat source facility 1B shown in FIG. 5 is provided corresponding to a plurality of heat source devices 2A to 2C for cooling or heating the heat medium and each of the heat source devices 2A to 2C, and the primary for pressure-feeding the heat medium. Pumps 3A to 3C, a first feed header 4A that collects the heat medium from the heat source devices 2A to 2C, secondary pumps 6A to 6C that feed the heat medium from the first feed header 4A, and these secondary pumps Inverters 7A to 7C for controlling the rotational speeds of 6A to 6C, the second feed header 4B to which the heat medium is fed from the secondary pumps 6A to 6C, and the air conditioner to which the heat medium is supplied from the second feed header 4B As well as the return header 10 that is returned to the heat source devices 2A to 2C, and the first feed header. 4A and the second feed header 4B The first bypass 11 and the first bypass valve 12 to be connected, the second bypass 19 that connects the first feed header portion 4A or the vicinity thereof and the return header portion 10 or the vicinity thereof, and the number of operating heat source devices 2A to 2C. And a control device 8 for performing control and operation control of the secondary pumps 6A to 6C (inverters 7A to 7C) and opening control of the first bypass valve 12.

A bypass flow meter 17 for measuring the flow rate of the heat medium flowing through the first bypass 11 and a differential pressure meter 16 for measuring the differential pressure between the first feed header 4A and the second feed header 4B are disposed; and header pressure difference P, based operation frequency f, the bypass flow rate Q _b, are disposed flow rate calculation unit 20 for calculating a heat medium conveying flow.

[Measurement method of heat medium flow rate]
When measuring the flow rate of the heat medium, the secondary pumps 6A to 6C, the second feed header 4B, the bypass 11, the first flow, with the flow path to the external load devices 9, 9. In the circulation system around the 1-feed header 4A, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each of the secondary pumps 6A to 6C. FIG. 6 shows the obtained PQ curve together with the PQ curve in the case of the heat medium pump alone. In addition, the PQ curve obtained by experiment contains a strainer, a check valve, piping resistance, and the like.

  Based on the relational expression, a calculation formula of the pump flow rate Qi using the inter-header differential pressure P as a parameter at an arbitrary pump operating frequency f is obtained.

In the flow rate calculation device 20, the calculation formula includes the differential pressure P between the headers measured by the differential pressure gauge 16, and the operating frequency f of the secondary pumps 6A to 6C, which is a set value for the frequency controller. by giving, to calculate each flow rate _{Q i} of each secondary pump 6A-6C, the bypass flow meter 17 has measured the total flow _{Q P} to the flow _{Q i} and the sum of respective secondary pump 6A-6C flow rate _{Q M} passing through the main pipe 15 is calculated by subtracting the flow rate _{Q b.}

  The specific calculation procedure is omitted because it has already been described in the above [1 pump type heat source equipment] column.

[Other examples]
(1) Although the example of application to the 1-pump system heat source facility and the 2-pump system heat source facility has been described in the above embodiment, the present invention provides a plurality of pumps that pump at least liquid between the first header and the second header. A pump is provided, a frequency controller for variably controlling the pump rotation frequency is provided corresponding to each pump, a bypass connecting the first header and the second header is provided, and a liquid flowing through the bypass The present invention can be applied to general piping system equipment provided with a bypass valve for adjusting the flow rate and further provided with a control device for controlling the operation of the pump and controlling the opening degree of the bypass valve.

It is a piping diagram showing 1A heat source equipment 1A. It is a flowchart of the flow measurement method of the present invention. It is a graph which shows the relationship (PQ curve) between the flow volume Q of the heat carrier in the real machine of 1 pump system heat source equipment 1, and the differential pressure P between headers. It is a graph which shows the relationship between the calculated value by a flow measurement method, and an actual value. It is a piping diagram showing 2 pump system heat source equipment 1B. It is a graph which shows the relationship (PQ curve) with the flow volume Q of the heat carrier in the real machine of 2 pump system heat source equipment 1B, and the differential pressure P between headers. It is a piping diagram which shows the conventional 1 pump system heat source equipment 50.

Explanation of symbols

  1A ... 1 pump system heat source equipment, 1B ... 2 pump system heat source equipment, 2A-2C ... heat source equipment, 3A-3C ... heat medium pump (primary pump), 4 ... feed header, 4A ... first feed header, 4B ... first 2-feed header, 6A-6C ... secondary pump, 7A-7C ... inverter, 8 ... control device, 10 ... return header, 11 ... first bypass, 12 ... bypass valve, 13 ... bypass, 14A-14C ... frequency controller , 16 ... differential pressure gauge, 17 ... bypass flow meter, 19 ... second bypass, 20 ... flow rate calculation device

Claims (3)

One or a plurality of heat source devices for cooling or heating the heat medium, provided corresponding to each heat source device, a heat medium pump for pumping the cooled or heated heat medium, and provided for each heat medium pump And a frequency controller that variably controls the pump rotation frequency, a feed header that collects the heat medium from the heat source device, an external load device that is supplied with the heat medium from the feed header, and heat exchange between the external load devices The returned heat medium is returned, the return header distributed to each heat source device, the bypass connecting the feed header section or its vicinity and the return header section or the vicinity thereof, and the flow rate of the heat medium flowing through the bypass are adjusted. 1-pump system piping system comprising a bypass valve for controlling the operation of the heat medium pump and an opening control of the bypass valve,
A bypass flow meter for measuring the flow rate of the heat medium flowing through the bypass, and a differential pressure meter for measuring a differential pressure between the feed header and the return header,
In the circulation system around the heat medium pump, the heat source device, the feed header, the bypass, and the return header, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each heat medium pump. Based on the above, an equation for calculating the pump flow rate Q using the pressure difference P between headers as a parameter at any pump operating frequency f is obtained,
By giving the calculation formula the differential pressure P between the headers measured by the differential pressure gauge and the operating frequency f of the heat medium pump, which is a set value for the frequency controller, the flow rate Q _{i of} each heat medium pump. together with respectively calculated by subtracting the flow rate Q _b of the from the total flow rate Q _P to the flow rate Q _i by summing the bypass flowmeter has measured the respective heating medium pump, a calculating means calculates the conveying flow of the heating medium Flow measurement method for piping system equipment. A plurality of heat source devices that cool or heat the heat medium, a primary pump that is provided corresponding to each heat source device and that pumps the cooled or heated heat medium, and a heat pump that collects the heat medium from the heat source device. A one-feed header, a plurality of secondary pumps that feed the heat medium from the first feed header, a frequency controller that is provided corresponding to each secondary pump, and that variably controls the pump rotation frequency, and the secondary pump The second feed header that collects the heat medium, the external load device to which the heat medium is supplied from the second feed header, and the heat medium heat-exchanged by the external load device are returned and distributed to each heat source device A return header, a first bypass and a first bypass valve that connect the first feed header and the second feed header, and a second bypass that connects the first feed header portion or its vicinity and the return header portion or its vicinity. And before In piping system equipment 2 pump type and a control device for controlling the opening degree of the heat source device operating units control and operation control, and the first bypass valve of the secondary pump,
A bypass flow meter for measuring the flow rate of the heat medium flowing through the first bypass, and a differential pressure meter for measuring a differential pressure between the first feed header and the second feed header,
In advance, in the circulation system around the secondary pump, the second feed header, the first bypass, and the first feed header, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each secondary pump, Based on this relational expression, a formula for calculating the pump flow rate Q using the header differential pressure P as a parameter at any pump operating frequency f is obtained,
By giving the calculation formula the differential pressure P between the headers measured by the differential pressure gauge and the operating frequency f of the secondary pump which is a set value for the frequency controller, the flow rate Q _{i of} each secondary pump. together with respectively calculated by subtracting the flow rate Q _b of the flow rate Q _i from the total flow rate Q _P obtained by summing the bypass flowmeter has measured the respective secondary pump, and characterized by calculating the transport rate of the heating medium Flow measurement method for piping system equipment. A plurality of pumps for pumping at least liquid are disposed between the first header and the second header, and a frequency controller for variably controlling the pump rotation frequency corresponding to each pump is provided. A bypass connecting the header and the second header is provided, a bypass valve for adjusting the flow rate of the liquid flowing through the bypass is provided, and a control device for controlling the operation of the pump and the opening degree of the bypass valve is provided. In the liquid transfer section of the piping system equipment
A bypass flow meter for measuring a flow rate of liquid flowing through the bypass, and a differential pressure meter for measuring a differential pressure between the first header and the second header,
In the circulation system surrounding the first header, the heat medium pump, the second header and the bypass, a relational expression between the header differential pressure P and the pump flow rate Q is obtained for each heat medium pump in advance. Based on the above, a formula for calculating the pump flow rate Q using the inter-header differential pressure P as a parameter at any pump operating frequency f is obtained,
By giving the calculation formula the differential pressure P between the headers measured by the differential pressure gauge and the operating frequency f of the heat medium pump, which is a set value for the frequency controller, the flow rate Q _{i of} each heat medium pump. together with respectively calculated by subtracting the flow rate Q _b of the from the total flow rate Q _P to the flow rate Q _i by summing the bypass flowmeter has measured the respective heating medium pump, a calculating means calculates the conveying flow of the heating medium Flow measurement method for piping system equipment.

Images