JPS63247549A - Hot water supply system - Google Patents

Abstract

PURPOSE:To reduce the overshoot of hot water temperature by parallell-connecting two water heaters, disposing a circulation pump in the return pipe, disposing a water flow rate sensor upstream of the joint of the supply pipe and the return pipe, and disposing a flow rate regulator in the water line of one of the water heaters. CONSTITUTION:When a hot water tap 6 is opened, water is fed through a supply pipe 4 and detected by a water flow sensor 15. If a warming circulation operation is under way at this time, the electric supply to an electric heater 10 and a circulation pump 9 is suspended, and, upon detecting a water flow greater than the minimum operating flow rate by a water flow rate sensor 22 in a first water heater 2, the heating is started. A flow rate regulator 13 disposed in a bypass pipe 12 is controlled to a target temperature which is set by a remote controller. Then, hot water heated by the first water heater is mixed with water supplied through the bypass pipe 12, and the mixed hot water at the set temperature is delivered by regulating the flow rate based on the detected temperature by a temperature sensor 14. When the flow rate detected by the flow rate sensor 15 becomes greater than the set flow rate, a flow rate regulator 35 is opened to cause water to be supplied to a second water heater 3 as well to heat up to a temperature higher than is set by the remote controller. Therefore, the overshoot of hot water temperature can be reduced.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a water heater.

(Conventional technology) Conventionally, hot water in the pipe leading from the water heater to the hot water faucet becomes cold water due to heat radiation, and in view of the problem that cold water is discharged for a while even when the hot water faucet is opened, hot water does not come out easily. , a system has been proposed in which a circulation path is formed between a water heater and a hot water faucet to maintain heat and circulate the water.

For example, in Japanese Patent Application Laid-Open No. 60-'233445, the water temperature and circulation flow rate in the circulation path are detected, the amount of heat required to heat the water to the set temperature is calculated, and the water heater is intermittently combusted. This is shown here.

(Problem to be solved by the invention) However, with this conventional type, the amount of heat required during heat retention circulation is much smaller than that during normal hot water supply, so if the water heater is large and has a high capacity, combustion will occur. A slight error in time causes the circulating water temperature to overshoot with respect to the set temperature, making it extremely difficult to control the hot water temperature during heat retention circulation.

On the other hand, if a small, low-capacity water heater is used, there is a problem in that a large amount of hot water cannot be expected to be produced when hot water is supplied.

The present invention solves the above-mentioned conventional problems, and enables large quantities of hot water to be dispensed using two water heaters during hot water supply, and allows combustion of only one water heater during heat retention circulation, thereby reducing overshoot in water temperature. The aim is to provide a water heater that can

(Means for solving the problems) In order to achieve the above object, the present invention provides the following (4)
It has been completed. In other words, two water heaters are connected in parallel, connected to a hot water supply tap via a common outgoing pipe, and a return pipe is connected from the outgoing pipe near the hot water tap to the middle of the water supply pipe common to the two water heaters. are connected to form a circulation path consisting of a water heater, outgoing pipe, return pipe, etc. in parallel, a circulation pump is installed in the return pipe, and a water flow sensor is installed upstream of the connection with the return pipe in the water supply pipe. and at least one of the two water heaters is provided with a flow regulator having an electric driving means in its water passage, and when the water flow sensor does not detect a flow rate, the flow regulator is set to a fully closed position. Like to be driven.

(Function) When hot water is not being supplied, the flow rate regulator is in the fully closed position and the
Since the passageway of one water heater is closed, the hot water is only available from the other one! It circulates through the llI vessel.

When the water temperature is lower than the set temperature by a certain value or more, the water is heated by combustion in the water heater.

When the hot water tap is opened, the water flow sensor detects the start of water supply, stops the circulation pump, and the water heater heats the supplied water to the set temperature and dispenses hot water. When the amount of hot water supplied is large, that is, when the flow rate detected by the water flow sensor exceeds a predetermined flow rate, the flow rate regulator is opened.
Run water through the water heater.

In other words, when hot water is being supplied, it is possible to produce a large amount of hot water using two water heaters connected in parallel, and when hot water is not being supplied, the r-p circulates through one water heater, so the amount of combustion during thermal circulation is small. It can reduce overshoot of water temperature. Moreover, since it is sufficient to circulate the water at the minimum operating water flow rate of one water heater, the amount of circulating water can be reduced and heat radiation loss can be reduced.

(Example) In Fig. 1, (1) is the main body of the water heater, and ? s1
It has a built-in water heater (2) and a second water heater (3). The first and second water heaters (2) and (3) are connected in parallel and are supplied with water from a common water supply pipe (4). (5) is an outgoing pipe that leads to the hot water tap (6), and (7) is a return pipe that connects from the hot water tap (6) to the water supply pipe (4), and the return pipe (7) has a check valve. (8), a circulation pump (9), and a hot water storage tank Oυ equipped with an electric heater aa. (L2) is a bypass pipe that branches off from the middle of the water supply pipe (4) and connects to the outgoing pipe (5), and is a flow rate regulating pipe equipped with an electric drive means.
They have rape 03. A4 is a temperature detector provided downstream from the confluence of the outgoing pipe (5) and the bypass pipe (b). (A) is a water flow sensor installed downstream of the branching point with the bypass pipe (□□□) of the water supply pipe (4) and upstream of the junction with the return pipe (7), and Qf9.αη are each It is a check valve.

In this embodiment, the first and second water heaters (a, (
a+ is the water flow layer and temperature detected by the water flow rate sensor ■, (to) and temperature sensor □□□ installed on the water inlet side of the heat exchanger wan, ct1), and the set temperature tv (not shown) of the remote controller, respectively. TB) and the heater, and burner Q◆
, (c) The amount of combustion is controlled. In addition, each of the water heaters (2) and (3) is equipped with a flow rate regulator (E) and (TO), and the set temperature (Ta2) of each water heater (2) and (3) is set so that the maximum capacity for controlling the hot water temperature by the amount of combustion is not exceeded. )
, (Ta2), the water flow rate is automatically adjusted. However, as shown in Figure 2, the second water heater (3
) is controlled to the fully closed position when the detected flow rate of the water sensor α is below the predetermined flow rate 2, and when the flow rate is above the predetermined flow rate, the flow rate regulator (7) is controlled to the fully closed position according to the set temperature (Ta2) of the water heater as described above. controlled by.

The operation of the water heater having such a configuration will be explained. When the operation switch (not shown) is turned on for the first time, if the hot water tap (6) is closed, water will not be supplied from the water supply pipe (4), so the water flow sensor α will not detect any flow. In this case, the electric heater αq is powered on and the circulation pump (9) is energized. The flow rate regulator (7) is configured so that the detected flow rate of the water flow sensor σG is a predetermined flow rate (for example, 5 l/min).
) In the following cases, it is controlled to the fully open position, so
Hot water flows only to the first water heater (2). So, it consists of a first water heater (2), an outgoing pipe (5), a return pipe (7), etc.? ″r
Hot water is circulated in the i-ring circuit, and the temperature of the circulating water is detected by a temperature sensor α4 installed in the middle of the outgoing pipe (5). The detected temperature is lower than the set temperature (TS) of the remote controller, and the temperature deviation is the first
If the deviation (for example, 15 degrees) or more, the burner J of the first water heater (2) is fired. Therefore, the circulating hot water Q is heated by the electric heater CIQ and the first water heater (2). As a result, when the deviation between the temperature detected by the temperature detector H and the set 1 degree is less than the second deviation (for example, l 2 deg), the combustion of the burner 2 is stopped, and the electric heater α
Heat only with Q.

When the temperature detector α4 detects a temperature equal to or higher than the set temperature of 1 degree (TS), the power supply to the electric heater (10) is stopped.

Further, if a temperature higher than the set temperature q (Ts) continues to be detected for a certain period of time, the circulation pump (9) is also stopped. Also, the deviation between the first detected temperature and the set temperature (TS) is the first deviation (15 de
g,), burner Q1 does not burn,
Heating is performed only with the electric heater αQ, and the set temperature (T
When detecting the humidity above S), heating by the electric heater UC> is stopped, and when the humidity exceeds the set humidity (TS) for a certain period of time, the circulation pump (9) starts exuding water. In addition, if the first detected temperature is already higher than the set temperature (TS), the electricity to the electric heater αQ is stopped, and the constant-open set temperature (T
S) If the above condition continues to be detected, the circulation pump will also stop.

Now, the hot water in the circulation circuit will eventually cool down due to natural cooling, but the temperature detector α will detect the set temperature (TS).
When the temperature drops by more than a certain degree (for example, 3 degrees), the heat retention cycle starts. That is, the electric heater α is energized and the circulation pump +91 is energized, and the operation is resumed as described above.

Next, the action during hot water supply will be explained. When the hot water tap (6) is opened, water is supplied from the water supply pipe (4) and the water quality sensor Q5 detects this, and if the hot water circulation operation is in progress, the electric heater is activated and the circulation pump (9) is sent. energization is stopped. 1st
The water volume sensor (1) of the water heater (2) is at the minimum operating water ffl
(2l/min) or more is detected, heating is started. Here, the set temperature (TS2) of the first water heater (2) is:
The temperature is set higher than the set temperature W (T S ) of the remote controller. That is, TS2-TS-11)C, and () is set in advance according to the flow rate of the total water sensor 4. On the other hand, Bypass 'Z! 12) 4: The provided flow rate regulator a3 is controlled with the set temperature (TS) of the remote controller as the target. Thus, the high temperature (TS2) hot water heated by the first water heater (2) and the water supplied from the bypass pipe (12) are mixed, and the water is heated based on the temperature detected by the temperature sensor α. The flow regulator port adjusts the water flow to the set temperature (
TS) mixed hot water is supplied.

When supplying a large amount of hot water, that is, when the flow rate of the water flow sensor αQ exceeds the predetermined flow rate (57/m1n), the flow rate regulator (to), which was controlled to the fully closed position, is opened and the second hot water S unit (3 ). Like the first water heater (2J), the second water heater (3) is also heated to a set temperature (TS3) higher than the gamma setting on the remote control.The first and second water heaters ( 21. The hot water heated in (3) is passed through the bypass pipe (12)
When the water comes out, it is mixed and hot water is supplied.

When the hot water tap (6) is closed, the water flow sensor 4 detects this and returns to the initial state. That is, when power is turned on to the electric heater Oq, the circulation pump (9) is energized and the temperature of the circulating water is detected, and as a result, if necessary, a warming operation is performed.

(Effects of the Invention) The present invention has the following excellent effects.In other words, when supplying hot water, it is possible to supply a small amount of hot water by burning only one water heater, and to use two water heaters. It is possible to supply a large amount of hot water, and since only one water heater can be burned during thermal circulation, the amount of combustion is small, reducing overshoot of water temperature, and the circulation flow rate can be reduced, which reduces heat loss. .

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of essential parts of the embodiment. (1)...Water heater body (2)...First water heater (3)...Second water heater (4)...Water supply pipe (5)...Outgoing pipe ( 6) ... Water tap (7) ... Projection pipe (9) ... Circulation pump q9 ... Water sensor Patent Shujin Co., Ltd. Noritz Representative Toshibe Ota

Claims (1)

[Claims] Two water heaters are connected in parallel, connected to the hot water tap via a common outgoing pipe, and a return pipe is connected from the outgoing pipe near the hot water tap to the middle of the common water supply pipe to the two water heaters. A circulation pump is provided in the middle of the return pipe, a water flow sensor is provided upstream of the connection with the return pipe in the water supply pipe, and at least one of the two water heaters is equipped with a water flow sensor. 1. A hot water supply apparatus, characterized in that a flow rate regulator having an electric drive means is provided in a water passage, and the flow rate regulator is driven to a fully closed position when the water flow sensor does not detect a flow rate.