JPH06137678A - Hot water feeding device - Google Patents

Abstract

PURPOSE:To improve a hot water feeding characteristic during an intermittent use of a large amount of hot water at a shower and the like in response to a capability of a hot water feeding device in which hot water of high temperature heated by a heat exchanger is mixed with water so as to feed hot water and to improve a convenience in use of the device. CONSTITUTION:There are provided a fed water temperature sensing device 1 arranged in a water passage W extending to a heat exchanger 3, a water amount sensing device 2 for sensing an operation state, a water amount control device 7, and a water amount control means 16 for sensing a stopped operation in response to a signal got from the water amount sensing device 2, sensing a starting of operation in response to a signal from the water amount sensing device 2 within a predetermined time and adjusting a water amount with a water amount control device 7 for a specified period of time in response to a water feeding temperature got by a water feeding temperature sensing device 1 when an outlet temperature sensing device 5 detects a lower hot water feeding temperature than the set temperatures of temperature switches 19, 20 and 21. Then, even if the water feeding temperature is low, a pre-cooling during a re-operation can be made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater having improved hot water outlet temperature characteristics when it is restarted after being stopped.

[0002]

2. Description of the Related Art In recent years, hot water heaters have improved hot water outlet temperature characteristics upon reuse. The conventional water heater will be described below. A conventional water heater of this type has a structure as shown in FIG. Water passes from the water inlet through the water inlet temperature detecting device 1 provided in the water passage W and is divided into two paths downstream thereof, and the water in one of the water passages W passes through the water amount detecting device 2 to generate heat in the heat exchanger 3. Absorb. The water in the other bypass passage S that bypasses the heat exchanger 3 passes through the on-off valve 6, merges with the hot water from the hot water outlet M, passes through the hot water outlet temperature detecting device 5, and is discharged from the faucet. In this way, the hot water heated by the heat exchanger 3 and the water flowing through the bypass passage S were mixed to obtain a large amount of hot water according to the capacity of the water heater. In the figure, 8 is a main solenoid valve of the gas supply passage, 9 is a downstream valve of the main solenoid valve 8, a proportional valve that changes the amount of fuel supplied to the gas burner 10 according to the load, 11 is a fan that sends combustion air to the gas burner 10. Is.

[0003]

However, in the water heater having such a structure, as shown in 1 of FIG.
When the hot water heated in the heat exchanger 3 is not fully exhausted after the operation is stopped, if the open / close valve 6 is closed, the hot water in the heat exchanger 3 causes so-called post-boiling. H becomes large. Then, as a means for solving such a problem, it is easily conceivable to open the on-off valve 6 while the hot water heated by the heat exchanger 3 is exhausted after the operation is stopped. According to this means, so-called post-boiling H due to the hot water in the heat exchanger 3 becomes small when the hot water in the heat exchanger 3 is not cooled as shown in 2 of FIG. Heat exchanger 3 as shown
When the high temperature hot water heated in
Grows larger. This phenomenon has a problem that the lower the water temperature is, the larger the precooling D becomes, and the hot water supply characteristics are deteriorated during intermittent use such as in a shower.

The present invention solves the above-mentioned conventional problems, and provides a convenient water heater having excellent hot water supply characteristics during intermittent use by reducing after-boiling during re-operation, especially pre-cooling. The purpose is to

[0005]

In order to achieve this object, a water heater according to the present invention is provided with a water temperature detector for detecting a water temperature provided in a water passage to a heat exchanger and a water amount for detecting an operating state. A detection device, a water amount control device that controls the amount of hot water supplied, a bypass passage that is provided in parallel with the heat exchanger in the water passages before and after the heat exchanger via an on-off valve that controls the amount of water passage, and an outlet that detects the hot water temperature. A temperature detection device and an operation stop is detected by a signal of the water amount detection device, and an operation start is detected by a signal of the water amount detection device within a predetermined time from this, and,
When the outlet temperature detecting device detects a temperature equal to or lower than the set temperature, the water amount controlling device is provided with control means for restricting the amount of water for a certain period of time according to the water entering temperature detected by the inlet water temperature detecting device.

[0006]

According to the present invention, when the operation is restarted within a predetermined time after the operation of the means is stopped, the water temperature is controlled by the control means for squeezing the water quantity by the water quantity control device for a certain time according to the water temperature detected by the water temperature detection device. Even if the temperature is low, the pre-cooling at the time of re-operation can be made small, and a water heater with excellent usability with excellent hot water supply characteristics during intermittent use such as a shower can be provided.

[0007]

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

FIG. 1 shows an embodiment of the present invention, in which water passes through a water inlet temperature detecting device 1 from a water inlet and is divided into two paths downstream thereof, and the water in one of the water passages W passes through a water amount detecting device 2. As described above, heat is absorbed by the heat exchanger 3 and passes through the hot water outlet temperature detecting device 4 in the hot water outlet M. The water in the other bypass passage S that bypasses the heat exchanger 3 passes through the on-off valve 6, joins the hot water from the hot water passage M of the heat exchanger 3, and controls the outlet temperature detection device 5 and the hot water supply amount. Hot water is discharged from the faucet through 7. The original solenoid valve 8 that opens and closes the gas passage from the gas inlet,
The combustion air is supplied through a proportional valve 9 that controls the gas supply amount according to the load, and the combustion air is supplied by a fan 11 and mixed with the preceding gas and burned by a burner 10.

The operation start of the water heater is input by the operation switch 18 of the external input device 17, the set temperature is input by the temperature switches 19, 20, 21 of the external input device 17, and the tap water temperature of the appliance is set in the tap water passage M. It is converted into an electric signal by the outlet temperature detection device 5 provided, and the output signal thereof is input to the control device 12. Similarly, the incoming water temperature is converted into an electrical signal by the incoming water temperature detecting device 1 provided in the water passage W, and the incoming water amount is converted into an electrical signal by the water amount detecting device 2 provided in the water passage W, and the output signal thereof is controlled. Input to the device 12.

The control device 12 includes an external input device 17, an incoming water temperature detecting device 1, a water amount detecting device 2, and an outlet temperature detecting device 5.
Of the combustion amount and water amount of the burner 10 according to the input signal of the burner 10 and the signals of the combustion amount determination means and water amount determination means 13 drive the original solenoid valve 8, the proportional valve 9, and the fan 11. Combustion amount control means 14, on-off valve control means 15 for driving the on-off valve 6 of the water passage S by the input signal of the hot water temperature detection device 4, and the water amount control for a certain period of time according to the input signal of the inflow water temperature detection device 1. Water amount control means 16 for controlling the amount of hot water supplied from the water heater by squeezing the device 7.
It consists of and.

FIG. 2 shows an example of a specific circuit of the control device 12. The control device 11 is composed of a microcomputer 24 and peripheral devices. The microcomputer 24 shown here is a so-called one-chip microcomputer having a CPU, a ROM, a RAM, and an input / output unit. The incoming water temperature detecting device 1, the water amount detecting device 2, the outgoing hot water temperature detecting device 4, and the outlet temperature detecting device 5 are the analog multiplexer 2
2. The microcomputer 2 via the A / D converter 23
4 and is used to send each input signal. On the other hand, an electric signal is sent from the output section of the microcomputer 24 to the original solenoid valve 8, the proportional valve 9 and the fan 11 via the D / A converter 25.

Next, an example of a sequence diagram of the processes S1 to S17 of this water heater is shown in FIG. In S1, the operation switch 18 of the external input device 17 is turned "ON", and the set temperature is input by the temperature switches 19, 20, 21. When the faucet is opened in S2 and water flows into the water passage and the amount of water detected by the water amount detecting device 2 becomes equal to or more than the amount of added water, the opening / closing valve 6 of the bypass S is opened in S3, and the ignition sequence is started in S4. In S5, the combustion amount and the water amount of the burner 10 are determined based on the set temperature of the external input device 17, the input signal of the incoming water temperature detecting device 1, and the input signal of the water amount detecting device 2, and in S6 and S7, the input signal of the hot water temperature detecting device 5 and the outside The combustion amount and the water amount of the burner 9 are adjusted so that the input signals of the set temperature of the input device 17 are the same. When the amount of water detected by the water amount detecting device 2 becomes less than or equal to the amount of fire extinguishing water in S8, the combustion of the burner 10 is stopped in S9, and S10
The on-off valve 6 of the water passage S is closed at step S5, and when 5 minutes have elapsed since the combustion of the burner 10 was stopped at step S17, the process returns to step S2. If the water amount detected by the water amount detecting device 2 becomes equal to or more than the ignition water amount within 5 minutes within a predetermined time after the combustion of the burner 10 is stopped in S11, S12
The ignition sequence is entered with, and the incoming water temperature detection device 1 is entered with S13.
In accordance with the water input temperature, the water amount control means 16 forcibly reduces the water amount by the water amount control device 7, and in S14 the burner 10 receives the input signals from the external input device 16, the water input temperature detection device 1, and the water amount detection device 2. Determine the amount of combustion. If the hot water outlet temperature of the heat exchanger 3 is equal to or higher than a predetermined temperature in response to the input signal of the hot water outlet temperature detecting device 4 in S15, the open / close valve 6 of the bypass passage S is opened in S16. If the hot water outlet temperature of the heat exchanger 3 is lower than or equal to a predetermined temperature, the heat exchanger 3 is heated by the burner 10. If the hot water outlet temperature of the heat exchanger 3 is higher than or equal to the predetermined temperature, the open / close valve 6 of the bypass passage S is S16. Is opened and the process returns to S6.

According to such a sequence, when the hot water discharge temperature of the heat exchanger 3 is equal to or higher than the predetermined temperature when the operation is restarted within the predetermined time after the operation is stopped, the open / close valve 6 of the bypass passage S is opened. The hot water supply temperature of 4 in FIG. 5 is available. When the hot water outlet temperature of the heat exchanger 3 is low, the hot water supply temperature 5 in FIG. 5 can be obtained by opening the on-off valve 6 after the heat exchanger 3 is heated without opening it. Although this characteristic changes depending on the incoming water temperature, the precooling can be prevented by cooling the amount of water with the water amount control device 7 according to the incoming water temperature.
Can be maintained at. In this way, after-boiling and pre-cooling are reduced at any water temperature at the time of re-operation, and a hot water heater with excellent hot water supply characteristics during intermittent use such as a shower is provided.

[0014]

As described above, in the water heater of the present invention, the opening / closing valve is effectively opened / closed according to the hot water outlet temperature of the heat exchanger, and the water amount is reduced by the water amount control device according to the incoming water temperature. Further, after-boiling due to high-temperature hot water in the heat exchanger and low water temperature and pre-cooling due to excessive cooling water from the bypass passage are reduced, the hot water supply characteristics during intermittent use are excellent, and a user-friendly effect is provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a water heater according to the present invention.

[Figure 2] Circuit diagram

FIG. 3 is a sequence diagram of the same.

FIG. 4 is a configuration diagram of a conventional water heater.

[Figure 5] Hot water supply characteristic diagram

[Explanation of symbols]

 1 Water temperature detector 2 Water amount detector 3 Heat exchanger 4 Hot water temperature detector 6 Open / close valve 7 Water amount controller 12 Controller

Claims (1)

[Claims] 1. A water inlet temperature detecting device for detecting a water inlet temperature provided in a water passageway to the heat exchanger, a water amount detecting device for detecting an operating state, a water amount control device for controlling a hot water supply amount, and a front and rear heat exchangers. A bypass passage that is provided in the water passage in parallel with the heat exchanger via an on-off valve that controls the water flow rate, and an outlet that is provided in the water passage downstream of the confluence of this bypass passage to detect the hot water supply temperature. A temperature detecting device and a signal from the water amount detecting device detect an operation stop, a signal from the water amount detecting device detects an operation start within a predetermined time, and the hot water supply temperature detected by the outlet temperature detecting device is higher than the set temperature. A water heater provided with control means for squeezing the amount of water by the water amount control device for a certain period of time according to the water input temperature detected by the water temperature detection device when the water temperature is low.