KR20090103729A - System and method for controlling water feeding pressure - Google Patents

Abstract

PURPOSE: A system and method for controlling the water supply pressure are provided to control the supply pressure of the hot or cold water generated with a heat source unit. CONSTITUTION: A system for controlling the water supply pressure comprises followings. Heat sources(1) generate the cold and hot water. Load devices(12) are located between a supply water conduit(9) of cold and hot water and a water returning conduit(10). A control device(11) controls the supply pressure of cold and hot water. The control device includes a valve differential pressure obtaining member, a minimum differential pressure detecting member, and a water supply pressure setting member. The water supply pressure setting member sets up the water supply pressure in order to higher than the pre-set minimum differential pressure value set by minimum differential pressure detecting member.

Description

Hydraulic pressure control system and hydraulic pressure control method {SYSTEM AND METHOD FOR CONTROLLING WATER FEEDING PRESSURE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure control system and a hydraulic pressure control method for controlling the hydraulic pressure of cold / hot water generated by a heat source machine to a load device (such as a fan coil unit or an air conditioner).

Conventionally, as one of the water pressure control which controls the water pressure of the cold / hot water generated by the heat source to the load device, for example, in the system shown in Patent Literature 1, a plurality of cold and hot water from the heat source is provided between the water supply line and the return line. The differential pressure between the input side and the output side of the load device positioned at the terminal is measured as the terminal differential pressure among the load devices, and the water pressure of the hot and cold water from the heat source device to the load device is set based on the measured terminal differential pressure.

According to the system shown in this patent document 1, when the water supply pressure of cold / hot water from a heat source machine to a load apparatus is changed based on the differential pressure (terminal differential pressure) between the input side and the output side of the load apparatus located in the terminal, and the terminal differential pressure is small. The water supply pressure of cold and hot water becomes high, and when the terminal differential pressure is large, the water supply pressure of cold and hot water falls.

For example, when the load device is an air conditioner, the water supply pressure of cold / hot water from the heat source device to the air conditioner is maintained so that the differential pressure (terminal air conditioner differential pressure) between the input side and the output side of the air conditioner (terminal air conditioner) located at the end is maintained at 1.0 kg / cm 2. This is controlled. Thereby, it becomes possible to reduce the conveyance power of cold / hot water to an air conditioner, and can realize energy saving.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2005-299980

However, according to the conventional water pressure control method described above, since the end air conditioner differential pressure is maintained at, for example, 1.0 kg / cm 2, the following problems arise when the end air conditioner is low load. The problem will be described below.

The air conditioner includes a cold / hot water coil and a valve for adjusting the flow rate of cold / hot water to the cold / hot water coil. In this air conditioner, at maximum load, a differential pressure of, for example, 1.0 kg / cm 2 is required. In this case, at the maximum load of the air conditioner, a differential pressure of 0.3 kg / cm 2 is applied to the valve, and a differential pressure of 0.7 kg / cm 2 is applied to the cold / hot water coil.

On the other hand, when the load of the air conditioner is small, the resistance of the valve is high, and a differential pressure of about 1.0 kg / cm 2 is applied to the valve in the vicinity of the total closing of the valve. That is, the valve is sufficient if a differential pressure of 0.3 kg / cm 2 is sufficient. However, when the terminal air conditioner is at a low load, a differential pressure of approximately 1.0 kg / cm 2 is applied, resulting in a loss of energy.

In addition, it is conceivable to control the water supply pressure so that a differential pressure of 0.3 kg / cm 2 is always applied to the valve of the terminal air conditioner. However, in such a control method, when the load demand from the other air conditioner increases at the time of the low end air conditioner. The pressure difference in the air conditioner is insufficient, resulting in a problem that the design flow rate cannot be maintained.

The present invention has been made to solve such a problem, and its object is to provide a low load without causing a problem that a differential pressure of another load device having a large load demand is insufficient at the time of low load of the terminal load device. The present invention provides a hydraulic pressure control system and a hydraulic pressure control method capable of saving energy in a secondary pump of a city.

In order to achieve this object, the present invention provides a heat source for generating cold and hot water, a plurality of load devices provided between a water supply line and a return line of cold and hot water from the heat source device, and the transmission of cold and hot water from the heat source device to these load devices. In a water pressure control system including a control device for controlling the water pressure, a differential pressure measurement for measuring the differential pressure between the inlet side and the outlet side of the valve for adjusting the flow rate of the hot and cold water flowing through the load device to each load device. A means for obtaining a valve differential pressure obtaining means for acquiring a valve differential pressure measured by the differential pressure measuring means of each load device and a minimum differential pressure for extracting a minimum differential pressure from the valve differential pressure acquired by the valve differential pressure obtaining means in the control device. The heat source unit such that the extraction means and the minimum differential pressure extracted by the minimum differential pressure extraction means are equal to or more than a predetermined value. The water supply pressure setting means which sets the water supply pressure of cold / hot water from a load apparatus to a load apparatus was provided.

In the present invention, each load device measures the differential pressure between the inlet side and the outlet side of the valve for adjusting the flow rate of the hot and cold water flowing through its load device as the valve differential pressure. For example, assuming that the load device is an air conditioner, and the air conditioner is provided with a valve for adjusting the flow rate of the hot and cold water to the cold / hot water coil, and the differential pressure measuring means is provided as the existing means, the differential pressure measuring means The differential pressure between the inlet side and the outlet side of the valve measured by is sent to the control device as the valve differential pressure.

The control device acquires the valve differential pressure sent from each load device, extracts the minimum differential pressure from the obtained valve differential pressure, and transfers the cold and hot water from the heat source device to the load device so that the extracted minimum differential pressure becomes equal to or more than a predetermined value. Set the water pressure.

In this case, for example, when the load device at the end is a low load, and the load demand from other load devices is large, and the valve differential pressure of the load device becomes the minimum differential pressure, the minimum differential pressure is a predetermined value (for example, 0.3 kg / cm 2). The water supply pressure of cold / hot water from the heat source device to the load device is set to be equal to or greater than).

Therefore, when the load request from another load device becomes large at the time of low load of the terminal load device, there is no problem that the design flow rate cannot be maintained because the differential pressure in the load device is insufficient. In addition, the differential pressure applied to the valve of the terminal load device is as small as possible while ensuring the differential pressure in the other load device in which the load demand is increased. Thereby, the energy saving of the secondary pump at the time of low load is attained, without causing the problem that the differential pressure of another load device with a big load demand is insufficient at the time of the low load of the terminal load device.

It is also possible to realize the present invention as a hydraulic pressure control method, not as a hydraulic pressure control system. In the water pressure control method, a heat source generating cold and hot water, a plurality of load devices provided between the water supply line and the return line of cold and hot water from the heat source machine, and the water supply pressure of the cold and hot water from the heat source machine to these load devices are controlled. A system including a control device, comprising: a differential pressure measurement step of measuring a differential pressure between an inlet side and an outlet side of a valve for adjusting the flow rate of cold / hot water flowing through the load apparatus for each load apparatus as a valve differential pressure; A valve differential pressure acquisition step of acquiring the valve differential pressure of each measured load device, a minimum differential pressure extraction step of extracting a minimum differential pressure from the valve differential pressure acquired by the valve differential pressure acquisition step, and a minimum extracted by this minimum differential pressure extraction step Set the water supply pressure of cold / hot water from the heat source device to the load device so that the differential pressure becomes equal to or more than a predetermined value. Provides a set pressure transmitting step.

According to the present invention, the valve differential pressure of each measured load device is acquired, the minimum differential pressure is extracted from the obtained valve differential pressure, and the cold and hot water from the heat source device to the load device is set such that the minimum differential pressure is equal to or more than a predetermined value. Since the water supply pressure is set, for example, when the load device at the end is a low load, the load demand from other load devices is large, and the valve differential pressure of the load device becomes the minimum differential pressure, the minimum differential pressure is not less than a predetermined value. The water supply pressure of cold / hot water from the heat source device to the load device is set as much as possible. Energy saving of the secondary pump can be achieved.

1 is an instrumentation diagram showing a configuration of an embodiment of a water pressure control system according to the present invention.

2 is a diagram showing an outline of an internal configuration of a load device in this hydraulic pressure control system.

3 is a flowchart for explaining a hydraulic pressure control function of the control device in the hydraulic pressure control system.

4 is a functional block diagram of a main part of a control device in this hydraulic pressure control system.

<Code description>

1 (1-1 to 1-3)... Heat source machine

2 (2-1 to 2-3). Primary pump

3-1, 3-2... Watering header

4… Return header

5... Bypass pipeline

6 (6-1 to 6-3)... Secondary pump

6-1a to 6-3a... inverter

7... Bypass pipeline

8… Bypass valve

9... Water supply line

10... A return pipe

11... controller

12 (12-1 to 12-3)... Load appliance

12A... Cold and hot water coil

12B... Pan

L… Supply passage of cold and hot water

V (V1 to V3)... valve

S1... Measure

13... Pressure sensor

11A... Valve differential pressure acquisition part

11B. Differential pressure extraction

11C... Water pressure setting part

11D... Water pressure controller

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on drawing. 1 is an instrumentation diagram showing a configuration of an embodiment of a water pressure control system according to the present invention.

This water pressure control system is described for heat sources (1-1 to 1-3) and heat sources (1-1 to 1-3) for generating cold and hot water such as cold and hot water generators, heat pumps, refrigerators and boilers. Primary pumps 2-1 to 2-3, water feed headers 3-1, 3-2, return header 4, water feed header 3-1, and return header provided as 4) the first bypass conduit 5 provided between the secondary pumps 6-1 to 6-3 provided between the water supply header 3-1 and the water supply header 3-2, and the water supply header ( 2nd bypass line 7 provided between 3-1) and feed water header 3-2, the bypass valve 8 provided in the bypass line 7, the water supply line 9, and the return line (10) and a control device (11), and a load device (12-1 to 12-3) such as a fan coil unit or an air conditioner is provided in parallel between the water supply line (9) and the return line (10). have.

In this water pressure control system, the cold / hot water, which is pressurized by the primary pumps 2-1 to 2-3 and added to the heat amount by the heat source devices 1-1 to 1-3, is supplied to the water supply header 3-1. It is sent, it is further conveyed by the secondary pumps 6-1 to 6-3, and is supplied to the water supply line 9 through the water supply header 3-2, and load apparatuses 12-1 to 12-3. Through the return pipe 10, the return header 4 is reached, and is again pumped by the primary pumps 2-1 to 2-3 to circulate the above path.

In the circulation path of the cold and hot water, the pressure of the cold and hot water discharged from the water supply header 3-2 is supplied to the water supply line 9 from the heat source devices 1-1 to 1-3 to the load devices 12-1 to 12-3. The pressure sensor 13 measured as the measured value PSpv of the water supply pressure of cold / hot water of a furnace is provided. In addition, the secondary pumps 6-1 to 6-3 are provided with inverters 6-1a to 6-3a for adjusting the rotation speed of the pumps, and the load devices 12-1 to 12-3. The valves V1 to V3 for adjusting the flow rate of the hot and cold water flowing through the load devices 12-1 to 12-3 are provided.

The outline of the internal structure of the load apparatus 12 (12-1 to 12-3) is shown in FIG. The load device 12 includes a cold / hot water coil 12A and a fan 12B, and a valve V is provided in the supply passage L of cold / hot water to the cold / hot water coil 12A.

The valve V is an existing means for measuring the physical quantity required for adjusting the opening degree of the valve V, and flow rate measuring means for measuring the flow rate of the cold water flowing through the valve V and the inlet of the valve V. Measuring means S1 serving as a differential pressure measuring means for measuring the differential pressure between the side and the outlet side is provided. In this embodiment, the flow rate of the cold water measured by this measuring means S1 is used as the load device flow rate Q, and the differential pressure between the inlet side and the outlet side is sent to the control device 11 as the valve differential pressure ΔPV. I'm trying to.

The transmission of the load device flow rate Q and the valve differential pressure ΔPV from the load device 12 to the control device 11 may be wireless or wired.

The control apparatus 11 is implemented by the hardware which consists of a processor and a memory | storage device, and the program which cooperates with these hardware and implements various functions as a control apparatus, and has a water pressure control function as a function peculiar to this embodiment. Hereinafter, the water pressure control function which the control apparatus 11 has is demonstrated according to the flowchart shown in FIG.

The control device 11 acquires and stores the load device flow rates Q1 to Q3 and the valve differential pressures? PV1 to? PV3 from the load devices 12-1 to 12-3 (step S101). The minimum differential pressure ΔPVmin having the smallest value is extracted from the obtained valve differential pressures ΔPV1 to ΔPV3 (step S102).

Next, the control apparatus 11 considers this extracted minimum differential pressure (DELTA) PVmin as a differential pressure of a control object, and transmits it so that this differential pressure of this control object may be predetermined value (0.3 kg / cm <2> in this example). The set value PSsp of the water pressure is determined (step S103).

And the control apparatus 11 makes the secondary pump (so that the measured value PSpv of the water pressure from the pressure sensor 13 become the set value PSsp based on this determined water pressure setting value PSsp). Adjust the rotation speed of 6-1 to 6-3). At this time, even if the rotation speed of the secondary pumps 6-1 to 6-3 is a lower limit value, when the measured value PSpv of the water pressure does not reach the set value PSsp, By adjusting the opening degree, the measured value PSpv of the water pressure is set to the set value PSsp (step S104).

Here, for example, the load device 12-1 at the end is a low load, the load demand from the other load device 12-2 is large, and the valve differential pressure ΔPV2 of the load device 12-2 is the minimum differential pressure. Think about this case. In this case, the control device 11 extracts the valve differential pressure ΔPV2 of the load device 12-2 as the minimum differential pressure ΔPVmin, and sets the water pressure so that the minimum differential pressure ΔPVmin becomes 0.3 kg / cm 2. (PSsp) is determined.

Therefore, even when the load request from the load device 12-2 increases at the time of low load of the terminal load device 12-1, the differential pressure in the load device 12-2 is insufficient, so that the design flow rate The problem of not being able to maintain it does not arise. In addition, the differential pressure applied to the valve V1 of the terminal load device 12-1 is as small as possible while ensuring the differential pressure in the load device 12-2 in which the load request is increased.

Accordingly, the secondary pump at low load (without causing a problem that the differential pressure of the other load device 12-2 having a large load request is insufficient at the time of low load of the terminal load device 12-1) Energy saving of 6) is planned.

The functional block diagram of the principal part of the control apparatus 11 is shown in FIG. The control apparatus 11 includes 11 A of valve differential pressure acquisition parts, the minimum differential pressure extraction part 11B, the hydraulic pressure setting part 11C, and the hydraulic pressure control part 11D.

The valve differential pressure acquisition unit 11A acquires valve differential pressures? PV1 to? PV3 from the load devices 12-1 to 12-3. The minimum differential pressure extraction unit 11B extracts the minimum differential pressure ΔPVmin from the valve differential pressures ΔPV1 to ΔPV3 acquired by the valve differential pressure acquisition unit 11A.

The water pressure setting unit 11C determines the water pressure setting value PSsp such that the minimum differential pressure ΔPVmin extracted by the minimum differential pressure extraction unit 11B is 0.3 kg / cm 2 or more.

The water pressure control unit 11D adjusts the rotation speed of the secondary pumps 6-1 to 6-3 so that the measured value PSpv of the water pressure from the pressure sensor 13 becomes the set value PSsp, The opening degree of the bypass valve 8 is adjusted.

This valve differential pressure acquisition part 11A, the minimum differential pressure extraction part 11B, the hydraulic pressure setting part 11C, and the hydraulic pressure control part 11D are implement | achieved as a processing function of the control apparatus 11. As shown in FIG.

In addition, in the above-described embodiment, the example in which the cold / hot water coil is provided in the load device 12 has been described. However, the load device may be a load device in which only one of the cold water coil and the hot water coil is provided. That is, it is possible to apply similarly to the system which circulates only cold water and the system which circulates only hot water. In addition, the system may be provided separately from the cold water coil and the hot water coil.

In addition, in the above-mentioned embodiment, in order to simplify description, the example which used three heat source machines and three load apparatuses was demonstrated, The quantity of heat source machines, a load apparatus, etc. is not limited to the above-mentioned quantity, but is suitably Can be set freely.

Claims (2)

A control unit for controlling the heat supply pressure for generating cold and hot water, a plurality of load devices provided between the water supply line and the return line for the cold and hot water from the heat source device, and the water supply pressure for the cold and hot water from the heat source device to these load devices. In a hydraulic pressure control system including a device, Each of the load device, And a differential pressure measuring means for measuring the differential pressure between the inlet side and the outlet side of the valve for adjusting the flow rate of the hot and cold water flowing through the own load device as the valve differential pressure, The control device, Valve differential pressure acquiring means for acquiring the valve differential pressure measured by the differential pressure measuring means of each load device; A minimum differential pressure extraction means for extracting a minimum differential pressure from the valve differential pressure acquired by the valve differential pressure acquisition means; A water pressure setting means for setting a water pressure of cold / hot water from the heat source device to the load device such that the minimum differential pressure extracted by the minimum differential pressure extraction means is equal to or greater than a predetermined value. system. In a system including a heat source for generating cold and hot water, a plurality of load devices provided between the water supply line and the return line of cold and hot water from the heat source device, and a control device for controlling the water supply pressure of cold and hot water from the heat source device to these load devices. In the hydraulic pressure control method applied, A differential pressure measurement step of measuring, as a valve differential pressure, a differential pressure between the inlet side and the outlet side of the valve for adjusting the flow rate of cold / hot water flowing through the load apparatus for each of the load apparatuses; A valve differential pressure acquisition step of acquiring valve differential pressures of the respective load devices measured by the differential pressure measurement step; A minimum differential pressure extraction step of extracting the minimum differential pressure from the valve differential pressure acquired by the valve differential pressure acquisition step; Water pressure setting which extracts the minimum differential pressure from the valve differential pressure extracted by this minimum differential pressure extraction step, and sets the hydraulic pressure of cold / hot water from the heat source device to the load device so that the minimum differential pressure becomes equal to or more than a predetermined value. Hydraulic pressure control method comprising the step.