JP2611017B2 - Instant water heater hot water supply mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a hot water supply mechanism of an instantaneous water heater.

[Prior art]

Conventionally, the temperature of tap water from an instantaneous water heater is adjusted by changing the combustion amount of a burner for heating a heat exchanger. Although the combustion range of the burner is designed to be as wide as possible by using a plurality of burners, there is a limit. When the maximum combustion amount is increased, the minimum combustion amount is also increased.

[Problems to be solved by the invention]

With such an instantaneous water heater, it is difficult to obtain an appropriate temperature (for example, about 35 ° C.) hot water with a small flow rate when the temperature of clean water is high in summer. Further, in such adjustment of the tap water temperature, in intermittent use at relatively short time intervals, high-temperature tap water (overshoot) due to post-boiling in the heat exchanger.
And inconvenience such as cold water mixing (undershoot) due to ignition delay of the heat exchanger heating burner, and it takes a considerable time until the tapping temperature is stabilized. Therefore, the present invention provides a hot water supply mechanism of an instantaneous water heater that stabilizes a hot water supply amount and a hot water temperature while expanding a hot water supply control range, such as being able to supply a low temperature and a small amount of hot water even when the hot water temperature is high. Aim.

[Means for Solving the Problems]

The hot water supply mechanism of the instantaneous water heater according to the present invention includes a hot water path (1) including a heat exchanger, as illustrated in FIGS.
A water path provided in parallel with the hot water path (5);
After diverting the water to be heated to the hot water path and the water path, the hot water supply mechanism of the instantaneous water heater that mixes the hot water obtained by heating the hot water path and the water from the water path to output hot water. A burner (12) for burning the fuel gas to heat the heat exchanger; and a flow rate of hot water in the hot water path and water in the water path at a junction of the hot water path and the water path. A valve element to be changed (8) is connected to the valve element and supported so as to be able to move forward and backward, and moves the valve element forward and backward by a heat-responsive element (7) which expands or contracts by detecting the temperature of the hot water at the junction. ,
And an actuating body (11) operating a bias spring to open the water path side, a return spring (20) for applying a return force opposing the bias spring to the valve body, An operating mechanism (9) for moving the valve body forward and backward, and a merging path (6) for merging the hot water and the water passing through the valve body, the hot water from the hot water path side and the water from the water path side are provided. A mixing valve (4) that mixes the hot water and the water by changing the flow ratio between the hot water side and the water side by moving the valve body back and forth by the thermoresponsive element that expands or contracts at the temperature of the mixed hot water. ), A first temperature sensor (15a) for detecting a hot water temperature on the hot water path side, a second temperature sensor (15b) for detecting a hot water temperature on a merging flow path side of the mixing valve, A hot water temperature setting device (14) that sets the hot water temperature, and the hot water temperature set by this hot water temperature setting device Correspondingly it performs combustion control by supplying the combustion gas to the burner so that the hot water temperature is to be detected is higher than the set temperature in the first temperature sensor,
Then, a control means (controller 13) for controlling the operation mechanism to adjust the position of the valve body so that the hot water temperature detected by the second temperature sensor becomes the set hot water temperature, After performing the burner combustion control so that the hot water temperature on the hot water path side becomes higher than the set temperature in accordance with the hot water temperature detected by the first temperature sensor, the burner is controlled based on the hot water temperature detected by the second temperature sensor. Along with controlling the supply amount of the combustion gas, the valve element is moved by expansion or contraction of the heat-responsive element due to a mixed hot water temperature of hot water from the hot water path side and water from the water path side, and The hot water supply of the set hot water temperature is performed by changing a flow rate ratio with the water.

[Operation]

The hot water supply mechanism of this instantaneous water heater is obtained by dividing the supply water to be heated into a hot water path including a heat exchanger and a water path provided in parallel with the hot water path, and then heating the hot water path. Hot water is supplied by mixing with water from a hot water channel. The hot water temperature is set by the hot water setting device, and based on the hot water temperature detected by the first temperature sensor, the control means controls the hot water temperature on the hot water system side to be higher than the set hot water temperature. As a control for obtaining the hot water temperature, the supply of combustion gas to the burner is controlled, and the position of the valve element of the mixing valve is adjusted. By the way, the mixing valve is a valve element that changes the flow ratio of hot water in the hot water path and water in the water path at the junction of the hot water path and the water path. A valve body is moved by a heat-responsive element that expands or contracts by detecting the temperature of the hot water on the road side, and the biasing spring acts to open the water path side. It includes a return spring for applying a return force, an operation mechanism for controlling the valve element through the operation element, and a merging flow path for joining hot water and water passing through the valve element. Therefore, after the position of the valve element is set by the control means, the thermo-responsive element detects the temperature of the hot water discharged from the junction, and as a result, the valve element moves forward and backward independently, and the flow rate ratio between the hot water and the water decreases. Be changed. As described above, the tapping control is performed by stepwise control based on burner combustion control, advance / retreat control of the mixing valve by the operating mechanism, and movement control of the valve element by the heat sensitivity of the thermoresponsive element.
Even when the minimum combustion amount of the burner is relatively large, hot water can be supplied at a low flow rate with a small flow rate. Also, in intermittent use at relatively short time intervals, the hot water in the hot water path has high-temperature hot water (overshoot) due to post-boiling in the heat exchanger.
Even if there is cold water mixing (undershoot) due to ignition delay of the burner or the like, it is not transmitted to the hot water in the combined flow path. As a result, a stable tapping water is obtained. Further, the burner controls the hot water temperature to a predetermined temperature higher than the set temperature based on the hot water temperature detected by the first temperature sensor in the hot water path and the set temperature of the hot water temperature setting device. Since the feedback control is performed so as to maintain the set temperature based on the hot water temperature detected by the second temperature sensor of the road, the tapping temperature can be stabilized. By controlling the supply of the combustion gas to the burner in accordance with the temperature of the hot water detected by the second temperature sensor, the temperature of the hot water on the hot water path can be controlled in accordance with the temperature of the hot water. Hot water temperature can be obtained.

【Example】

Hereinafter, the present invention will be described with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment of a hot water supply mechanism for an instantaneous water heater according to the present invention. Reference numeral 1 denotes a hot water path that passes through the heat exchanger 3 of the water heater 2. Water that branches in parallel with the hot water path 1 on the upstream side of the heat exchanger 3 and joins via the mixing valve 4 on the downstream side A path 5 is provided. As shown in FIGS. 2 (a) and 2 (b), the mixing valve 4 moves the valve body 8 by the heat responsive element 7 provided in the merging flow path 6 so that the water path 5 and the hot water path 1 An operation mechanism 9 such as an electric operation mechanism for setting the position of the thermally responsive element 7 and for changing the flow rate ratio is provided. Thermal response element 7
In this configuration, for example, wax is sealed and thermally expanded, and the direction of movement of the valve element 8 due to expansion is such that the amount of hot water in the hot water path 1 is reduced and the amount of water in the water path 5 is increased. The position of the thermal responsive element 7 is adjusted by an operating body 11 via a bias spring 10. The operating body 11 is operated by an operating mechanism 9 such as an electric operating mechanism as described above, and It is configured to move in the direction. FIG. 2A shows a state in which the amount of hot water in the hot water path 1 is large. In this state, when the wax expands and the thermally responsive element 7 thermally expands as shown in FIG. 2 (b), the valve body 8 is moved downward to reduce the amount of hot water in the hot water path 1, When the temperature of the hot water in the combined flow path 6 is decreased by increasing the amount of water in the flow path 5, and when the temperature of the hot water is decreased and the thermoresponsive element 7 contracts, the valve 8 is moved upward to reduce the amount of water in the water path 5. At the same time, by increasing the amount of hot water in the hot water path 1 and raising the temperature of the hot water in the junction flow path 6, the temperature of the hot water flowing through the junction flow path can be controlled. When the thermal response element 7 is displaced downward by the operating mechanism 9, the set temperature can be lowered, and when it is displaced upward, the set temperature can be raised. 12 is a burner for heating the heat exchanger 3, 13 is a controller,
Reference numeral 14 denotes a tapping temperature setting device, and reference numerals 15a and 15b denote temperature sensors such as a thermistor provided on the downstream side of the heat exchanger 3 in the hot water path 1 and the merging flow path 6, respectively.
Is based on the hot water temperature detected by the temperature sensor 15a of the hot water path 1 of the burner 12 and the set temperature of the hot water temperature setting device 14, and sets the hot water temperature to a predetermined temperature higher than the set temperature, for example, 20 ° C. higher than the set temperature. After performing the combustion control of the burner 12 so as to increase the temperature, feedback control is performed so as to maintain the set temperature based on the hot water temperature detected by the temperature sensor 15b of the combined flow path 6. The controller 13 controls the combustion amount of the burner 12 as described above, and also operates the operating mechanism 9 to set the position on the thermally responsive element 7. In the drawing, reference numeral 16 denotes a flow switch, 17 denotes a water amount control valve, 18 denotes a check valve, 19 denotes a tap hole, and 20 denotes a return spring.

【The invention's effect】

As described above, according to the present invention, the following effects can be obtained. a.The hot water whose temperature has been raised in the heat exchanger can be cooled by tap water and discharged from the tap, so that even when the minimum burner of the burner is relatively large, low-temperature hot water can be supplied. Even when the temperature of clean water is high, it is easy to obtain hot water of a suitable temperature (for example, about 35 ° C.) with a small flow rate. b. In intermittent use at relatively short time intervals, hot water in the hot water path may include high temperature hot water (overshoot) due to post-boiling in the heat exchanger or cold water due to ignition delay of the burner for heating the heat exchanger. Even if there is mixing (undershoot), the tapping temperature can be maintained at a constant temperature without being transmitted to the hot water in the combined flow path through the mixing valve, and a stable hot water supply can be realized. c.After adjusting the supply amount of the combustion gas to the burner according to the set hot water temperature, adjust the position of the valve body of the mixing valve, and adjust the position of the valve body by the action of the thermally responsive element based on the outlet water temperature. As a result, the flow ratio of hot water and water is adjusted to the hot water temperature,
A stable tap water temperature can be obtained. d. Based on detection of tapping temperature by the second temperature sensor,
By controlling the supply amount of the combustion gas to the burner, the stabilization of the hot water temperature can be improved.

[Brief description of the drawings]

FIG. 1 is a system explanatory view showing an embodiment of a hot water supply mechanism of an instantaneous water heater according to the present invention, FIG. 2 (a) is a sectional view showing a configuration of an embodiment of a mixing valve, and FIG. It is sectional drawing which showed operation | movement of the valve. DESCRIPTION OF SYMBOLS 1 ... Hot water path 2 ... Water heater 3 ... Heat exchanger 4 ... Mixing valve 5 ... Water path 6 ... Combined flow path 7 ... Thermal response element 8 ... Valve element 9 ... Operating mechanism 10 ... … Bias spring 11 …………………………………………………………………………………………………………………………………………………………. 20 ... Return spring

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Noritaka Morinaka 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (56) References JP-A-63-213747 (JP, A) JP-A-62 JP-A-2848956 (JP, A) JP-A-58-205043 (JP, A) JP-A-1-148558 (JP, U) JP-A-63-175378 (JP, U) JP-B-1-32899 (JP, B2) ) JP-B-63-20620 (JP, B2)

Claims (1)

(57) [Claims] 1. A hot water path provided with a heat exchanger, and a water path provided in parallel with the hot water path, and the hot water path is divided into the hot water path and the water path. A hot water supply mechanism of an instantaneous water heater that mixes hot water obtained by the heating of the above with water from the water path to discharge hot water, wherein the burner burns fuel gas to heat the heat exchanger; A valve body for changing a flow rate ratio between the hot water of the hot water path and the water of the water path at a junction of the water path and the water path; The valve body is moved forward and backward by a heat-responsive element that expands or contracts by detecting the temperature of the hot water, and the biasing spring acts on the bias spring to open the water path side. A return spring for applying an opposing return force, through the working body An operating mechanism for moving the valve body forward and backward, a merging path for merging the hot water and the water passing through the valve body, and a mixed hot water temperature of the hot water from the hot water path side and the water from the water path side; A mixing valve that mixes the hot water and the water by changing the flow rate ratio between the hot water side and the water side by moving the valve body forward and backward by the heat-responsive element that expands or contracts; A first temperature sensor for detecting a hot water temperature; a second temperature sensor for detecting a hot water temperature on a merging flow path side of the mixing valve; a hot water temperature setting device for setting a hot water temperature in the merging flow path; The combustion control is performed by supplying combustion gas to the burner so that the hot water temperature detected by the first temperature sensor according to the set hot water temperature of the setter becomes higher than the set temperature. The operating mechanism is controlled according to the temperature of the hot water to adjust the position of the valve body. Control means for performing the combustion control of the burner so that the hot water temperature on the hot water path side becomes higher than the set hot water temperature according to the hot water temperature detected by the first temperature sensor, and then the second temperature The amount of combustion gas supplied to the burner is controlled based on the detected hot water temperature of the sensor, and the expansion or contraction of the heat responsive element due to the mixed hot water temperature of hot water from the hot water path side and water from the water path side. Wherein the valve element is moved to change the flow rate ratio between the hot water and the water so that the hot water is supplied at the set hot water temperature.