JPS5816092B2 - Heat supply circulation device - Google Patents

Description

Detailed Description of the Invention The present invention provides a heat supply circulation system in which a cold heat source unit and a terminal unit are connected via separate piping. This provides a means to enable remote automatic control of the source itself.

Conventionally, in heat supply circulation devices such as cold/hot water type Centsil air conditioners, remote control from a terminal device is controlled by each terminal device, pressure feeder,
All electrical wiring was done between the heat source equipment and the main equipment.

In this method, a. It is necessary to have an on/off switch for remote control built into each terminal. b. It is necessary to conduct electrical wiring between each terminal and the main unit such as a heat source device. There are problems such as the need for a low-voltage electric circuit, which has the following drawbacks: (d) remote individual control becomes expensive; and (e) construction is troublesome.

The present invention eliminates the drawbacks of the prior art.

As a configuration for that purpose, the present invention separates the cold heat source device and the terminal and connects them with piping, and uses a pressure sending device such as a circulation pump to transfer the hot fluid to 5.
: * A heat supply circulation device for IJ circulation is provided, a check valve is provided near the pressure feeder, and the pressure difference between the discharge side of the pressure feeder including the check valve and the suction side or atmospheric pressure is detected. , a differential pressure switch is provided that turns ON when it drops to a first set value PL, and turns OFF when it exceeds a second set value PH, detects the circulation flow rate of the thermal fluid in the circulation path, and turns OFF the differential pressure switch. A flow rate switch is provided whose OFF operation flow rate Q1 is set to a lower value than the circulating flow rate Q2, and the pressure feeding machine is started by turning on the differential pressure switch, and the pressure feeding machine is stopped by turning the flow rate switch OFF. It is equipped with an electric circuit.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system diagram of a hot water heating system as an example for explaining the overall configuration of the present invention, in which a heat source device 1 and each terminal device 2a, 2b, 2c are connected by piping via a circulation pump 3. It forms a heat supply circulation circuit.

This heat supply circuit has a switch 5 that detects the internal pressure of the circuit.
In response, the pressurizing pump 6 is operated, and the check valve 7 is opened from the water tank 4.
A water supply device 8 that replenishes circulating water to the heat supply circuit through a safety valve circuit 9 that opens when the internal pressure of the circuit becomes higher than a set value due to thermal expansion etc. is connected to It regulates internal pressure.

Further, each of the terminals 2a, 2b, and 2c of this device is provided with a circulation path opening/closing valve 10, respectively.

This opening/closing valve 10 may be operated manually, or as shown in the terminal 2a, the fan 1
An electric valve 10a that operates in conjunction with 2 may also be used.

On the other hand, a check valve 13 is provided near the circulation pump 3, and a differential pressure switch 14 that detects the differential pressure across the circulation pump 30, including the check valve 13, and a flow rate switch 15 that detects the circulation flow rate are equipped. .

Next, the electrical control circuit diagrams shown in Figures 2 and 3 and the
The operating principle will be explained using a custom-made diagram of the state of circulation flow rate and differential pressure shown in the figure.

From state A in which all the circulation path on-off valves 10 of each terminal device are opened and the circulation pump 3 and heat source device 1 are operating, the number of operating terminal devices is gradually reduced to state B in which only one terminal device is in operation. , check valve 13 and terminal device circulation on/off valve 1
The pressure difference between the piping route 17 between 0 and the other route 18 becomes large.

This pressure difference is detected by the differential pressure switch 14, and the differential pressure switch 14 is already turned OFF at the state operating point A when the OFF operation set pressure PH of the differential pressure switch 14 is reached.

This differential pressure switch 14 is connected to the input side 25 of the thermotimer 16.
By connecting the output side circuit 26 in series with the electric circuit of the circulation pump 3 as shown in FIG. 2, a delayed operation is created to start and stop the circulation pump.

When the operating state B continues for a while, the delay operation of the thermo timer 16 ends, and eventually the electric circuit to the circulation pump 3 is turned off.
do.

However, the flow rate switch 15 is connected to the output circuit 26 of the thermotimer 16.

The flow rate switch 15 is provided in the electric circuit of the circulation pump 3 in the column, and the circulation pump continues to operate when the flow rate switch 15 is turned on.

Next, when the flow path opening/closing valve 10 of the last one terminal unit is closed, the flow rate switch 15 detects that the circulation flow rate has reached Ql at the position of the state operating point opening, and the electric circuit of the circulation pump 3 is activated. Turn OFF and stop it.

The check valve 13 functions to maintain the differential pressure between the pipes 17 and 18 at a pressure difference greater than or equal to the first set value PL, which is the ON pressure of the differential pressure switch 14, and the circulation pump 3 is stopped.

However, if the hot water is cooled or there is a leak from a shutoff valve, etc., the differential pressure decreases and reaches the state point C, which is the ON pressure of the differential pressure switch 14, the first set value PL, and the pressurization stops. The circulation pump 14 is started only for the purpose that the differential pressure switch 1
It stops again at state point 2 where it reaches the second set value PH which is the OFF pressure of 4.

In the case of a leak, the operation points C and 2 will be repeated, so care must be taken to prevent leaks from the shutoff valve, etc.

The delay operation circuit such as the thermo-timer mentioned above contributes to reducing the degree of turning on and stopping of the circulation pump 30 caused by the differential pressure switch 14.

When activated, when any one of the circulation path on-off valves 10 of the terminal is opened, pressure is released from the high pressure side of the piping path 17 to the piping path 18 side, the differential pressure decreases, and the differential pressure switch is activated. 14 is ONL and the circulation pump 3 is started.

In this case, the above-mentioned circulation operation state B is reached, but before the flow rate reaches the flow rate Q1 that turns off the flow rate switch 15, the differential pressure switch 14 senses the differential pressure PH that turns off the differential pressure switch 14, causing chattering. However, this chattering can be prevented by the delay operation of the front thermo timer 16.

In this way, the circulation pump can be started smoothly from any terminal.

Reference numeral 22 indicates a ladder to the branch, and 23 indicates a heat exchanger of the terminal.

Further, as shown in Fig. 3, the flow rate switch can be made of a double switch 15' or the like, and devices other than the circulation pump, such as the combustion control device 19, can be automatically started and stopped in conjunction with the opening/closing operation of the flow rate switch. .

24 indicates a power source.

Since the capacity of the terminal unit is controlled by the on-off valve of the terminal unit, in order to reduce fluctuations in the circulation flow rate of other terminal units due to the on-off valve operation, a bypass passage 20 is provided that links the discharge side and suction side of the circulation pump. The bypass passage 20 is interposed between the bypass passages 20 and the OFF operating pressure Po is applied to the OFF operation pressure Po of the differential pressure switch 14.
A constant pressure valve 21 set to a value higher than the F operating pressure PH may be provided.

A diagram of the circulating operation state at that time is shown in FIG.

As can be seen from the above configuration description, the present invention brings about the following effects.

(I) Unlike in the past, there is no need for any troublesome electrical wiring in the current system, and arbitrary individual remote operation from each terminal is possible.

(IT) Since all circulation paths to terminals that are not in use are closed, there is no wasteful heat loss from piping, making it energy efficient and economical.

(IIT) By using the differential pressure fluctuation before and after the pressure feeder including the check valve as the start signal for the pressure feeder such as a circulation pump, the fluctuation factor in which the internal pressure of the circulation circuit itself changes overall due to thermal expansion, etc. is eliminated. , it is possible to detect the output of only the pumping machine,
It can be used to change any set pressure using water supply equipment, etc.

(TV) By using a flow rate switch as the stop signal for a pressure feeder such as a circulation pump, the stop limit flow rate can be set to a lower flow rate than when starting and stopping is controlled using only a differential pressure switch, and the intermittent operation region can be reduced. .

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a hot water heating system showing an embodiment of the present invention, Fig. 2 is an electrical control circuit diagram, Fig. 3 is an electrical circuit diagram of another embodiment, and Fig. 4 is a differential pressure and circulation flow rate. Characteristic diagram of
FIG. 5 is a state characteristic diagram when a bypass circuit is also provided. 1...Cold heat source machine (heat source machine), 2a, 2b, 2c
,... Terminal unit, 3... Pressure feeder (circulation pump), 10a... Open/close valve, 13... Check valve, 14...・Differential pressure switch, 15...
・Flow rate switch, 20...Bypass passage.

Claims (1)

[Claims] 1. A cold heat source device and a terminal device are separated and connected via piping, and a heat supply circulation device is provided that forcibly circulates hot fluid using a pressure feeder such as a circulation pump, and a check valve is provided near the pressure feeder to prevent this reverse flow. Detects the differential pressure between the discharge side of the pressure feeder including the stop valve and the suction side or atmospheric pressure, and when it decreases to the first set value PL, ONL,
A differential pressure switch is provided that turns off when the pressure exceeds a second set value PH, detects the circulating flow rate of the thermal fluid in the circulation path, and sets the value to a value lower than that of the circulation flow path Q2 when the differential pressure switch is turned off.
A flow rate switch is provided to set the OFF operation flow rate Q1, and an electric path is provided to start the pumping machine when the differential pressure switch is turned on, and to stop the pumping machine when the flow rate switch turns OFF. Supply circulation device.