JPH03164650A - Hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To obtain a stable output hot water temperature by providing a flow rate control valve in a hot water supply tube, controlling to open or close the valve, and so eliminating variation in the output hot water temperature as to obviate an abrupt large flow rate change. CONSTITUTION:An output hot water tube 5 is connected to a hot water supply tube 10, and a plurality of hot water supply cocks 11a-11c and another drain flow rate control valve 12 from the cocks are provided in the tube 10. The valve 12 is controlled to be opened or closed by a controller 13, and the controller 13 detects the rate of flow rate change based on a flow rate signal from a flow rate sensor 7 of a hot water supplying apparatus 1 to control the valve 12. If it detects a flow rate decrease, it opens the vale 12 to drain, and to so regulate the flow rate Q in the tube to be held at a flow rate Q0 before the reduction, then to gradually throttle the valve 12, thereby smoothing the reduction rate of the flow rate Q so that combustion control can sufficiently follow up the flow rate reduction rate to reduce the flow rate Q in the state that the output hot water temperature is stabilized, and eventually to fully close the valve 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water heater capable of stabilizing the temperature of hot water.

[Prior art]

In conventional general water heaters, when hot water is supplied to multiple channels, as shown in FIG. +Cs was simply communicated.

In such a water heater, a plurality of channels CIt
If any of the cylinders (for example, ci) are closed while hot water is being tapped into Cz+ C3, the flow rate will decrease and a sudden large change in flow rate will occur, and combustion control will be performed in response to the change in flow rate, that is, the decrease in flow rate. This was done to stabilize the hot water temperature.

[Problems to be Solved by the Invention] In the above-mentioned conventional hot water supply device that discharges hot water into a plurality of taps, combustion occurs in response to a large flow rate change, that is, a decrease in flow rate, that occurs when one of the taps is closed during hot water dispensing with a plurality of taps. However, due to the delay in gas control, the reduction in combustion amount in response to the decrease in flow rate is delayed, and the amount of combustion is lower than the amount required to maintain the hot water outlet temperature at a predetermined temperature in response to the decreased flow rate. In addition to this, the can body itself has a heat capacity, so even if the combustion rate decreases in response to the flow rate, the hot water exit temperature becomes high and it is difficult to maintain the hot water exit temperature at an appropriate temperature. There was a problem in that the temperature of the tapped water became higher than a predetermined value, resulting in overshoot (see Fig. 5).

An object of the present invention is to solve the above-mentioned problems and provide a hot water supply device that can maintain a stable hot water temperature without changing the hot water temperature even when a large change in flow rate (reduction in flow rate) occurs due to closing of the cooker, etc. It is to be.

[Means to solve the problem]

In order to achieve the above object, the water heater of the present invention provides a flow control valve (for drainage) separate from the drain in the hot water supply pipe, and controls the opening and closing of the flow control valve with a controller, so that the hot water supply pipe suddenly enters the water supply pipe. It does not cause large changes in the flow rate, that is, it eliminates changes in the hot water temperature by increasing the amount of hot water from the water heater.

[Function] In the hot water supply apparatus of the present invention configured as described above, when a certain cooker is closed while hot water is being discharged from a plurality of cookers, the flow rate in the hot water supply pipe decreases three times. The controller detects this and opens the flow control valve and drains water from the hot water pipe, returning the flow rate in the hot water pipe to the state before the flow rate change, then gradually narrowing the flow control valve and finally opening it fully. By doing so, a sudden large change in the amount of 2 Jt does not occur in the hot water supply piping, so that the amount of hot water output from the water heater does not change significantly, and the hot water temperature does not change.

〔Example] Embodiments of the present invention will be described based on the drawings.

The water heater 1 has a heat exchanger 3 heated by a burner 2, and the heat exchanger 3 is connected to a water supply pipe 4 and a hot water outlet pipe 5.

A water supply temperature sensor 6 and a flow rate sensor 7 are installed in the water supply pipe 4, and a hot water outlet temperature sensor 8 and a hot water temperature regulating valve 9 are installed in the hot water outlet pipe 5.

The hot water outlet pipe 5 is connected to a hot water supply pipe 10, and a plurality of hot water supply pipes (three in this embodiment) are connected to the hot water supply pipe 10.
A, 11b, 11c, and a drainage flow rate control valve 12 separate from the valve are provided.

The opening and closing of the iit control valve 12 is controlled by a controller 13, and the controller 13 detects the rate of change in flow rate (around j) based on the flow rate signal from the flow rate sensor 7 of the water heater l, and opens and closes the flow control valve 12. It controls the

Now, when the flow M'm is detected as low, the flow rate control valve 12 is opened to drain water, the flow rate Q in the hot water supply pipe is adjusted to maintain the flow rate Q0 before the reduction, and then the flow rate control valve 12 is opened. The rate of decrease in the flow rate Q is gradually reduced, the combustion control is able to sufficiently follow the rate of decrease in the flow rate, the flow rate Q is decreased while the outlet temperature is stabilized, and finally the flow rate control valve 12 is fully closed. That is.

Figure 2 shows the flow rate change and the hot water temperature. Line I shows the hot water temperature.
At the time b) is closed, it suddenly decreases greatly and remains constant thereafter.

However, when a decrease in the flow rate is detected at time t1 and the flow rate control valve 12 is opened, the flow rate Q of the hot water supply pipe 10 decreases slightly and then recovers, as shown by the line
lb is temporarily restored to the flow rate Q before closing.

Next, the flow rate control valve 12 is gradually throttled, and the flow rate Q of the hot water supply pipe 10 is gradually decreased at a speed that allows the combustion control to sufficiently follow the rate of decrease in the flow rate, and finally the flow rate control valve 12 is gradually reduced.
fully closed and open (lla, 1lc)
) is made to match the flow rate Q of the hot water supply pipe 10.

By the above-described operation, the temperature of the hot water is kept substantially constant.

The above flow rate control operation will be explained with reference to the flowchart l' in FIG. and determines whether the rate of change in flow rate dQ/dt exceeds a predetermined value α.

The rate of flow rate change dQ/dt is less than or equal to the predetermined value α (dQ/d
In the case of t≦α), the flow rate is not controlled because the flow rate change is within a range in which the outlet temperature can be maintained at a preset value by controlling the fuel tA amount #.

The rate of flow rate change caused by the closure of Curtain llb dQ/
If dt exceeds the predetermined value α (dQ/d t >α), the flow IQ before the flow rate change occurs (that is, before closing the column Ilb) is stored.

Next, the flow rate If control valve 12 is rapidly fully opened, and the hot water supply pipe 10
The flow rate Q of is increased to be approximately equal to the flow rate Q0 before closing the column Ilb.

The flow rate Q of the hot water supply pipe 10 and the flow rate before the flow rate change (i.e., the flow rate Q)
The flow rate control valve 12 is kept fully open until both flow rates Q and Q become substantially equal.

When the flow rate Q of the hot water supply pipe 10 and the flow rate Q0 before the flow rate change become approximately equal (Q!=:Q,), the flow rate Q of the hot water supply pipe 10 gradually decreases at a speed that can be sufficiently followed by the combustion control. The flow rate control valve 12 is closed at a slow speed until the flow rate control valve 12 is fully closed.

In order to close the flow control valve 12 at a slow speed,
Combustion control can sufficiently follow the rate of change in flow rate to maintain the tapping temperature at a preset value.

When the flow rate control valve 12 is fully closed, the flow rate Q of the hot water supply piping 10 becomes equal to the sum of the amounts of hot water coming out of the hot water pipes lla and llc in use, and the system is in a standby state for the next change in flow rate.

Note that the flow control valve 12 and the controller 13 are connected to the water heater 1.
It may also be installed by incorporating it inside.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

When a large change in flow rate (reduction in flow rate) occurs due to the closing of the drain, etc., by controlling the opening and closing of the drainage flow control valve using the controller, a stable hot water temperature can be maintained without changing the hot water temperature. .

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a water heater according to an embodiment of the present invention, FIG. 2 is a graph showing fluctuations in hot water temperature and flow rate, FIG. 3 is a flowchart, and FIG. 4 is a conventional water heater FIG. 5 is a graph showing the fluctuations in the outlet temperature and flow rate. 1... Water heater, 2... Burner, 3... Heat exchanger, 4... Water supply pipe 5... Hot water outlet pipe, 6... Water supply temperature sensor, 7...
Flow rate sensor, 8... Hot water temperature sensor, 9... Hot water temperature adjustment valve, 10... Hot water supply piping, 11a, llb, llc
---Call (for hot water supply), 12...Flow control valve (for drainage), 13...Controller.

Claims (1)

[Claims] (1) A hot water supply device characterized in that a flow rate control valve is provided in the hot water supply piping, and by controlling the opening and closing of the flow rate control valve, sudden large changes in flow rate are prevented and changes in outlet temperature are eliminated.