JPH11211122A - Hot water circulated heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent empty bathtub heating by connecting a bypass pipe in an upstream pipe of a flow rate sensor from a downstream pipe of a heat exchanger heated by a heating device, providing a shut-off valve on the bypass pipe, and opening the shut-off valve when an output value of the flow rate sensor is a specified value or less. SOLUTION: Circulating hot water is controlled by a hot water temperature sensor 8, heaters 3 and 4, and a main controller 20, and supplied to a hot water heating terminal 12 through a feed pipe 10. The circulating hot water with the temperature thereof being lowered returns to a heat exchanger 5 through a return pipe 13, a hot water return pipe 14, an expansion tank 16, and a hot water circulating pump 7, and heated again by the heat exchanger 5. In the case a hot water heating terminal valve 11 is closed, and a flow rate sensor 18 outputs a value which is a set value or less, a shut-off valve 19 in a bypass line 15 connected to an upstream pipe of the flow rate sensor 18 is closed by the main controller 20. As a result, the hot water temperature sensor 8 secures a hot water flow rate for detecting a hot water temperature correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of using water as a heat medium.
The present invention relates to a hot water heating device that is heated and circulated for heating and other purposes.

[0002]

2. Description of the Related Art Heretofore, in this type, a bypass pipe in a hot water circulation circuit of a hot water heating apparatus has no shutoff valve and is always "open". FIG. 3 shows an example of a conventional gas hot water heating apparatus.

That is, the hot water pressurized by the hot water circulation pump 7 is heated by the heat exchanger 5, and performs a heating function at the hot water heating terminal 12 via the hot water outgoing pipe 9 and the hot water transporting outgoing pipe 10. The hot water whose temperature has been lowered by
The hot water returns to the expansion tank 16 via the hot water return pipe 14, and is pressurized again by the hot water circulation pump 7 to form a circulation circuit.

The main controller 17 controls a gas amount controller 3 and a gas combustion section 4 as heating devices based on an output signal of a hot water temperature sensor 8. At this time, reference numeral 15 denotes a bypass pipe, which exits the hot water outflow pipe 9 and is connected to the hot water return pipe 14.

[0005] Even if the hot water heating terminal valve 11 is closed, the hot water circulation flow rate is always ensured, and the output of the hot water temperature sensor 8 causes the gas combustion unit 4 to operate without any trouble and continue operation. it can.

[0006]

In this hot water heating apparatus, the output of the hot water circulating pump 7 is sometimes not efficiently operated because the bypass pipe 15 is always "open", that is, fixed. There is.

That is, when the hot water heating terminal valve 11 is open, a circulating hot water flow always exists, and the bypass pipe 15
There is no need to secure the hot water circulation flow rate. In other words, it is a wasteful flow that does not perform the work of heating with hot water.

Further, when there are multiple hot water heating terminals 12, even a little more pump head is required, but by stopping the useless flow, more heating terminals can be operated.

The present invention aims at energy saving and high performance in such a hot water heating apparatus.

[0010]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a shut-off valve in a bypass pipe and performs "open" and "close" control at a predetermined timing to effectively operate a hot water circulation pump. Can drive.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a heat exchanger for heating water, a heating device for heating the heat exchanger, and a temperature sensor for detecting hot water temperature. In the downstream line, a hot water circulating pump, an expansion tank having a function of releasing air from the circulating water are provided, and a return line to the expansion tank is provided with a flow rate sensor. A controller connects a bypass line to the upstream line of the sensor, and provides a shut-off valve in the bypass line, and controls the shut-off valve to be "open" when the output value of the flow sensor is equal to or less than a predetermined value. It is what constituted.

When the output value of the flow rate sensor is equal to or less than a predetermined value, that is, when the hot water heating terminal valve is "closed", the closing valve of the bypass pipe is controlled to be "open", so that the heating device is operated. The phenomenon in which the circulating flow rate is lost despite the operation, that is, the so-called "dry firing" is eliminated, and the operation can be continued.

Conversely, when the output value of the flow rate sensor is equal to or more than a predetermined value, the closing valve of the bypass pipe is closed so that unnecessary flow of circulating hot water is eliminated, so that a hot water heating terminal of more systems can be provided. You will be able to connect.

According to a second aspect of the present invention, when the detected value of the hot water temperature sensor is equal to or less than a predetermined value from the start of the operation and is within a predetermined time from the start of the operation, the close valve is controlled to be "open". The controller is configured as described above.

[0015] By closing the bypass pipe closing valve at the start of operation and normally closing, the wasteful flow of the circulating hot water is eliminated, thereby reducing the output of the hot water circulating pump and saving power. Alternatively, effective operation such as multi-system hot water heating terminals can be performed.

On the other hand, at the start of operation, the closed valve is opened, and the amount of internal circulation is increased, so that the circulating water inside the apparatus can be heated in a short time, and the startup time of the heating operation is increased. Can be shortened.

According to a third aspect of the present invention, the output of the hot water circulating pump is made variable and the closing valve is opened.
In this case, a controller is configured to control the pump output to be minimum.

At this time, when the output value of the flow rate sensor is equal to or less than a predetermined value, that is, when the hot water heating terminal valve is "closed", the closing valve of the bypass line is controlled to "open" and the hot water circulation pump is controlled. By minimizing the output, operation can be connected without any trouble while saving energy and reducing noise.

[0019]

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

(Embodiment 1) FIG. 1 is a configuration diagram of a gas hot water heating apparatus according to Embodiment 1 of the present invention.

In the drawing, 1 is an exterior body, 2 is an air supply port for gas combustion air, 3 is a gas amount controller, 4 is a gas combustion section, and 3 and 4 constitute a heater. 5 is a heat exchanger, 6 is an exhaust gas exhaust gas outlet, 7 is a hot water circulation pump, 8 is a hot water temperature sensor, 9 is a hot water outgoing pipe, 10 is a hot water carrying outgoing pipe, 11
Is a hot water heating terminal valve, 12 is a hot water heating terminal device, 13 is a transport return pipe, 14 is a hot water return pipe, 16 is an expansion tank that absorbs air from the circulating water and absorbs expansion and contraction, 15 is a bypass pipe,
19 is a shut-off valve, 18 is a flow sensor, and 20 is a main controller.

The main controller 20 controls the flow rate of the output of the flow rate sensor 18 to a predetermined value or less, for example, the minimum flow rate for the hot water temperature sensor 8 to accurately detect the hot water temperature, and generally, the flow rate to the bypass pipe 15. When the pressure falls below the value set in (normally 2-3 liters / minute), the closing valve 19 is opened.
Is configured to be controlled.

The operation and operation of the hot water heating apparatus configured as described above will be described.

The circulating hot water is supplied to the hot water outlet pipe 9 at 80 ° C. so that the temperature of the hot water temperature sensor 8, the heaters 3, 4 and the main controller 20 are controlled.
, And is conveyed to the hot water heating terminal 12 via the conveyer pipe 10. Then, the circulating hot water whose temperature has been lowered by performing the heating function flows through the hot water return pipe 14 and the expansion tank 16 via the transport return pipe 13, is pressurized by the hot water circulation pump 7, returns to the heat exchanger 5, and is heated again. It is operated continuously by doing.

At this time, when the hot water heating terminal valve 11 is closed, the flow sensor 18 outputs a value lower than the set value. Then, the main controller 20 operates and the closing valve 19 becomes “open”,
The hot water flow rate at which the hot water temperature sensor 8 can accurately detect the hot water temperature can be secured, and the operation of the apparatus can be continued without any trouble.

On the other hand, when the flow rate sensor 18 outputs a flow rate equal to or higher than the set flow rate, that is, when the hot water heating terminal valve 11
When "open", even if there is no flow in the bypass pipe 15, the hot water temperature sensor 8 can accurately detect the hot water temperature, so that the operation can be continued without any trouble even if the closing valve 19 is closed.

By operating the shut-off valve 19 closed, even if the hot water circulation pump 7 has the same output, more hot water heating terminals 12 can be connected and operated, and energy saving and high performance as a hot water heating apparatus can be achieved. Can be achieved.

(Embodiment 2) The only difference from Embodiment 1 is the configuration of the main controller. That is, the hot water temperature sensor 18
If the detected value is less than or equal to a predetermined value and within a predetermined time from the start of operation, the closing valve 19 is controlled to be "open".

Next, the operation and action will be described. Generally, this kind of gas hot water heating apparatus has circulating water inside the apparatus like the expansion tank 16. Therefore, it takes a considerable time to start up from a state where the equipment is cold as at the start of operation to a temperature of 80 ° C. where the circulating hot water performs a heating action.

Therefore, by opening the shut-off valve 19 unconditionally at the beginning of the operation, the internal circulation amount is increased, the output of the heating devices 3 and 4 is increased, and the internal temperature of the device is quickly raised. As a result, high-temperature water can be quickly supplied to the hot-water heating terminal 12 as well.

When the predetermined temperature is reached, the shut-off valve 19 is closed to eliminate wasteful flow of circulating hot water, thereby reducing the output of the hot water circulating pump and saving power. If the outputs are the same, effective operation such as multi-system hot water heating terminals 12 can be performed.

Here, the detection value of the hot water temperature sensor 18 is set to be equal to or less than a predetermined value and within a predetermined time from the start of the operation.
The same effect can be expected even if is closed.

(Embodiment 3) The difference from Embodiment 1 is that the output of the hot water circulating pump 7 is made variable and a controller is configured to control the pump output to a minimum when the closing valve 19 is "open". It is in.

That is, by minimizing the output of the hot water circulation pump 7 in addition to the same operation and operation as in the first embodiment, the power consumption of the pump can be greatly reduced. FIG. 2 shows an example of the characteristics of a general pump of this type.

In FIG. 2, A, B, and C denote the maximum output and C by changing the voltage or the like applied to the pump, thereby changing the rotation speed, the hot water circulation amount (Q) and the pressure (P). Indicates the minimum output. The current consumed at each output is indicated by a and c.

When this is applied to this embodiment, the closing valve 1
When 9 is "open", a controller is configured to apply a voltage or the like indicated by the C characteristic, and otherwise, a voltage or the like indicated by the A characteristic is applied. As an effect, the power consumption of the pump can be significantly reduced without hindering operation.

In general, this kind of hot water heating apparatus operates even when the heating operation is not performed, in order to prevent freezing of the apparatus when the outside air temperature in winter decreases. At this time, according to this embodiment, energy saving and noise reduction can be achieved without any trouble in driving, and the effect is very large.

[0038]

As described above, according to the present invention, a shutoff valve is provided in a bypass pipe, and the valve is opened and closed at a predetermined timing.
By switching the output of the hot water circulation pump together with the control, the hot water circulation pump can be effectively operated, and there is an advantageous effect that operation is not hindered, and energy saving and noise reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a hot water heating device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram of a hot water circulation pump of a hot water heating device according to a third embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional hot water heating apparatus.

[Explanation of symbols]

 5 Heat Exchanger 7 Hot Water Circulation Pump 9 Hot Water Outgoing Pipe 14 Hot Water Return Pipe 15 Bypass Pipe 18 Flow Rate Sensor 19 Closing Valve 20 Main Controller

Claims (3)

[Claims] 1. A heat exchanger for heating water is provided, and a heating device for heating the heat exchanger and a temperature sensor for detecting hot water temperature are provided in a downstream pipe of the heat exchanger, and circulated by a hot water circulation pump. An expansion tank having a function of extracting air from the circulating water is provided, and a flow sensor is provided in a return line to the expansion tank, and from a downstream line of the heat exchanger to an upstream line of the flow sensor. Connecting a bypass line, and providing a shut-off valve in the bypass line,
A hot water heating apparatus provided with a controller for controlling the closing valve to be "open" when an output value of the flow rate sensor is equal to or less than a predetermined value. 2. The control device according to claim 1, wherein the controller controls the closing valve to be opened when the detected value of the temperature sensor is equal to or less than a predetermined value from the start of operation and within a predetermined time from the start of operation. 2. The hot water heating apparatus according to 1. 3. The hot water heating apparatus according to claim 1, wherein the controller makes the output of the hot water circulating pump variable and controls the output of the hot water circulating pump to be minimum when the shut-off valve is “open”.