JPH08121796A - Operating method for circulation type water heater - Google Patents

Abstract

PURPOSE: To reduce the bore of a hot water supply tube and to decrease a piping execution cost by forming the bore of the tube to the degree of furnishing normal hot water supply load, and coping with a high load area including the maximum hot water supply load by raising the supply hot water temperature from a hot water supply heat source equipment. CONSTITUTION: Since cold water corresponding to hot water supply volume is fed to a water supply tube 7a and a hot water return tube 5 when hot water is supplied from a hot water supply position 2, a controller 11 generates a hot water supply load by the flow rate output of a flow rate sensor 8 and detects the volume. The controller 11 sets the temperature of the hot water supplied from a hot water supply heat source equipment 1 in response to the flow rate output corresponding to the not water supply load. When the load is increased from the normal state and the output exceeds the set value, the controller 11 decides the generation of high load hot water supply, sets the hot water supply temperature of the equipment 1 to a high temperature (about 80 to 90 deg.C) to supply the hot water, increases the ratio of the cold water, and resultantly increases the hot water supply amount after mixing by a combination faucet 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a circulating water heater, which is often applied to medium to large-scale hot water supply systems.

[0002]

2. Description of the Related Art A hot water supply pipe from a hot water supply source to a hot water mixing tap at a hot water supply point, a hot water return pipe returning from a hot water supply point to a hot water supply source, a circulation pump, and a hot water mixing tap and a hot water supply source from a water supply source, respectively. In the circulation type hot water supply device that has a water supply pipe that reaches the upstream side of the Temperature (generally about 40 ℃)
I am going out of the bath.

Even in a medium to large-scale hot water supply system to which such a circulating hot water supply device is applied, the hot water supply load is very sporadic, and the maximum hot water supply load generation time ratio is the total operating time. Often less than 10%.

However, in the conventional circulating water heater,
Even in the case of the maximum hot water supply load where the generation time ratio is small, the diameter of the hot water supply pipe is set large so that the hot water of the set temperature can cover the load.

[0005]

The amount of heat released from the pipe is
Since the larger the diameter, the larger the diameter of the hot water supply pipe in order to cover the maximum hot water supply load with a small generation time ratio as in the past, the amount of wasteful heat dissipation from the pipe is large and the overall efficiency However, there is a problem that the pipe construction cost becomes high as well as the cost. Accordingly, an object of the present invention is to solve such a problem.

[0006]

In order to solve the above-mentioned problems, in the present invention, a hot water supply pipe from the hot water supply heat source device to a hot and cold water mixing tap at a hot water supply place and a hot water supply return pipe returning from the hot water supply place to the hot water supply heat source device. In the circulation type hot water supply device equipped with a circulating pump, and a hot water / water mixing tap from the hot water supply source and an upstream side of the hot water supply heat source device, the hot water supply temperature from the hot water supply heat source device is higher than the set hot water supply load. We propose an operating method in which the load is set to a temperature higher than the normal hot water supply temperature, and when the load is lower than the set hot water supply load, the normal hot water supply temperature is set higher than the normal hot water supply temperature from the hot and cold water mixing tap. .

In the present invention, it is proposed that the hot water supply load is detected by the flow rate of cold water passing through the water supply pipe from the water supply source to the upstream side of the hot water supply heat source machine.

Further, the present invention proposes that the hot and cold water mixing tap in the above structure is constituted by a thermostat type hot and cold water mixing tap.

[0009]

When the load is higher than the preset hot-water supply load, the hot-water supply temperature from the hot-water supply heat source device is set to a temperature higher than the normal hot-water supply temperature, so that the amount of heat supplied per unit flow rate can be increased. Therefore, the diameter of the hot water supply pipe for covering the maximum hot water supply load can be reduced.

If the hot and cold water mixing tap is constituted by a thermostat type hot and cold water mixing tap, the fluctuation of the hot water supply temperature under high load and normal load can be automatically absorbed to stabilize the hot water discharge temperature.

[0011]

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is a system diagram schematically showing an embodiment of a circulating hot water supply apparatus to which the present invention is applied. Reference numeral 1 is a hot water supply heat source machine,
It is preferable that the hot water supply heat source device 1 is configured by an instantaneous hot water supply heat source device that can change the temperature of the hot water to be supplied in a short time with respect to the hot water storage type hot water supply heat source device having a large amount of water. Reference numeral 2 is a hot water supply point, and the hot water supply point 2 is provided with a hot and cold water mixing plug 3. The hot and cold water mixing valve 3 is a thermostat type hot and cold water mixing valve in which an element that responds to temperature and pressure is built into a hot and cold water mixing valve, and the mixing ratio of hot water and cold water is automatically adjusted to a temperature set by a temperature control handle or the like. Is preferred.

Reference numeral 4 is a hot water supply pipe from the hot water supply heat source machine 1 to the hot water supply point, and reference numeral 5 is a hot water supply return pipe from the hot water supply location 2 to the hot water supply heat source machine 1, which are continuous and constitute a circulation path, A circulation pump 6 is installed in the hot water supply return pipe 5. Further, on the upstream side of the hot water supply heat source machine 1, on the downstream side of the circulation pump 6, a water supply pipe 7a leading to a water supply source such as water supply is joined, and a flow rate sensor 8 is installed in the water supply pipe 7a. In addition, a check valve and the like are installed on the downstream side of the circulation pump 6 of the hot water supply pipe 7a and the hot water supply return pipe 5, if necessary, but they are not shown. Hot water supply piping 4
Is connected to the hot water side of the hot and cold water mixing tap 3 of the hot water supply point 2 via the connection pipe 9, and the cold water side of the hot and cold water mixing tap 3 is connected to the water supply pipe 7b installed at the hot water supply point 2 from the water supply source. Connected through. Reference numeral 11 is a control device, and the control device 11 is configured to control the operations of the hot water supply heat source device 1, the circulation pump 6, and the like. In addition, in FIG. 1, only the hot and cold water mixing plug 3 is shown in the hot water supply portion 2, but a hot water outlet that directly discharges hot water passing through the hot water supply pipe 4 without mixing with water can be provided as needed. .

In the above structure, when hot water is being discharged from the hot water supply point 2, cold water corresponding to the amount of hot water discharged flows into the hot water supply return pipe 5 from the water supply pipe 7a.
1 indicates that the hot water supply load is generated by the flow rate output of the flow rate sensor 8,
The amount can be detected. Therefore, the control device 11
Is a hot water supply heat source device 1 according to the flow rate output corresponding to the hot water supply load.
Set the temperature of hot water supplied from.

That is, when the flow rate output is equal to or less than the set value (for example, about 70% of the flow rate with respect to the maximum load assumed in advance), the control device 11 determines that the load is a normal hot water supply, and the hot water supply of the hot water supply source 1 is performed. Hot water is supplied by setting the temperature to a normal temperature of 50 to 60 ° C. The hot water of about 50 to 60 ° C which reaches the hot water side of the hot and cold water mixing tap 3 of the hot water supply point 2 through the hot water supply pipe 4 is mixed with cold water supplied to the cold water side through the water supply pipe 7b, and is normally used. The temperature is adjusted to about ℃ and the hot water is discharged.

When the hot water supply load further increases from such a normal hot water supply load state, that is, when the amount of hot water discharged through the hot and cold water mixing plug 3 of the hot water supply point 2 further increases, the hot water supply pipe 4 having a fixed diameter is supplied. Since there is a limit to the amount of hot water that can flow, it will not be possible to cover the amount of hot water required.

Therefore, in the present invention, when the hot water supply load increases from the normal state and the flow rate output exceeds the set value, the control device 11 determines that high-load hot water supply has occurred, and the hot water supply heat source device 1
Hot water is supplied by setting the hot water supply temperature to 80-90 ℃.

When such hot water of high temperature is supplied to the hot water side of the hot and cold water mixing tap 3, the proportion of cold water for obtaining hot water of about 40 ° C. is increased, so that the hot water side of the hot and cold water mixing tap 3 is supplied. Hot and cold water mixing tap 3 without changing the amount of hot water supplied
The amount of hot water discharged after mixing can be increased. That is,
A high hot water supply load including the maximum hot water supply load can be covered.

When there is no load, that is, when hot water is not discharged from the hot water supply point, cold water does not flow into the hot water supply return pipe 5 from the hot water supply pipe 7a, and the flow rate sensor 8 does not output a flow rate. Therefore, the control device 11 determines that the current state is no load, and performs control when there is no load. That is, the controller 11 sets the temperature of the hot water supplied from the hot water supply heat source device 1 to about 50 to 60 ° C. as in the case of the normal hot water supply load described above, and operates the circulation pump 6 to circulate the hot water. Warm water is circulated in the route to perform heat retention operation. In the warm-keeping operation, the temperature of the hot water supplied from the hot water supply heat source device 1 can be set lower than the set temperature for the normal hot water supply load.

As described above, according to the present invention, the diameter of the hot water supply pipe is set so as to cover the normal hot water supply load, and a high load region including the maximum hot water supply load is handled by increasing the hot water supply temperature from the hot water supply heat source machine. Therefore, in comparison with the conventional one in which the diameter of the hot water supply is set so as to cover the maximum hot water supply load, the theoretical simple calculation can reduce the pipe diameter as shown below. That is, assuming that the hot water supply temperature from the hot water supply heat source device assumed when setting the diameter of the hot water supply pipe in the conventional one is 60 ° C, and the cold water temperature supplied to the cold water side of the hot and cold water mixing tap through the water supply pipe is 20 ° C. When the set temperatures of the high temperature in the present invention are 80 ° C. and 90 ° C., respectively, the pipe diameter can be reduced as follows. At 80 ℃ ... 67% of the conventional pipe diameter, that is, (60-20) /
When (80-20) = 0.67 90 ° C ... 57% of the conventional pipe diameter, that is, (60-20) /
(90-20) = 0.57

[0020]

As described above, according to the present invention, since the diameter of the hot water supply pipe can be reduced as compared with the conventional one, the piping construction cost can be reduced and the surface area of the pipe can be reduced. There is an effect that the heat radiation loss amount due to can be reduced.

[Brief description of drawings]

FIG. 1 is a system diagram schematically showing the configuration of an embodiment of a circulation type hot water supply device to which the present invention is applied.

[Explanation of symbols]

 1 hot water supply heat source device 2 hot water supply point 3 hot and cold water mixing tap 4 hot water supply pipe 5 hot water return pipe 6 circulation pump 7a, 7b water supply pipe 8 flow sensor 9, 10 connection pipe 11 control device

Claims (3)

[Claims] 1. A hot water supply pipe from a hot water supply heat source device to a hot and cold water mixing tap at a hot water supply point, a hot water supply return pipe returning from the hot water supply point to the hot water supply heat source device, a circulation pump, and a hot water and water mixing tap and a hot water supply heat source device from the water supply source, respectively. In the circulating hot water supply device having a water supply pipe leading to the upstream side of the hot water supply device, the hot water supply temperature from the hot water supply heat source device is set to a temperature higher than the normal hot water supply temperature when the load is higher than the set hot water supply load. When the load is lower than the specified hot water supply load, the normal hot water supply temperature higher than the normal hot water supply temperature from the hot and cold water mixing tap is set, and the circulating hot water supply device is operated. 2. The operating method of the circulating hot water supply device according to claim 1, wherein the hot water supply load is detected by a flow rate of cold water passing through a water supply pipe from a water supply source to an upstream side of the hot water heat source machine. 3. The method for operating a circulating hot water supply device according to claim 1, wherein the hot and cold water mixing tap is constituted by a thermostat type hot and cold water mixing tap.