JPH0249480Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention is designed to proportionally increase or decrease the amount of gas supplied to the gas burner that heats the heat exchanger in accordance with the increase or decrease in the amount of water flowing through the heat exchanger. Regarding gas water heaters.

[Prior art]

In this type of gas water heater, the amount of gas supplied increases or decreases in proportion to the amount of water flowing through the heat exchanger, so even if the amount of water flowing changes, the hot water temperature remains almost constant. And the adjustment of the hot water temperature can be done by, for example,
As shown in Japanese Patent No. 61-72923, the ratio between the amount of water flowing to the heat exchanger and the amount of gas supplied is changed using a temperature control valve provided in conjunction with a diaphragm device that operates the gas valve.

[Problem that the invention attempts to solve]

In such conventional technology, when the ratio of the gas supply amount is decreased to lower the hot water temperature, the temperature of the heat exchanger decreases, so that moisture in the combustion gas condenses on the surface of the heat exchanger and drips as condensate. drop down. This kind of drain dissolves the sulfur oxides and nitrogen oxides in the combustion gas and becomes strongly acidic, so there is a problem that it corrodes the inside of heat exchangers and gas water heaters, reducing their durability. . Additionally, since it takes a certain amount of time for the water supply to pass through the heat exchanger, there is a problem that even if the ratio of water flow to gas supply is changed using the temperature control valve, the hot water temperature does not change immediately, resulting in a time delay. be.

As a means to solve these problems, the ratio of water flow and gas supply is kept constant, and the water heated by the heat exchanger is always hot water at a high temperature, and this is mixed with cold water by a mixing valve to reach the desired set temperature. One possible solution is to obtain hot water from the area. however,
In such technology, the range of temperature rise in the feed water heated by the heat exchanger is constant, so if the feed water temperature changes, the temperature of the hot water sent out from the heat exchanger also changes, and the temperature of the hot water sent out from the heat exchanger also changes. If the flow rate of water exceeds the maximum flow rate corresponding to the maximum capacity of the gas burner, insufficient heating will occur and the temperature of the hot water from the heat exchanger will drop, and in either case, the temperature of hot water from the gas water heater cannot be accurately controlled. The problem is that it disappears. In addition, the maximum flow rate will be large when the water supply temperature is high and small when the water supply temperature is low, so if you set the maximum flow rate for the former case, the maximum flow rate will be used when the water supply temperature becomes low. If you do this, the temperature of the hot water from the heat exchanger will drop, and if you set the maximum flow rate for the latter case, the gas burner will not be able to reach its maximum capacity even if the water flow rate is set to the maximum flow rate if the water supply temperature rises. First, there is the problem of not being able to demonstrate the maximum potential. The present invention attempts to solve these problems.

[Means for solving problems]

For this purpose, the gas water heater according to the present invention is provided in a water supply passage 10 communicating with a heat exchanger 16 heated by a gas burner 24, as shown in the attached drawings, and is arranged in a water supply passage 10 that communicates with a heat exchanger 16 heated by a gas burner 24. Diaphragm device 40 with a displacing diaphragm 41
In the gas water heater, the water supply passage 10 is provided with a gas valve 25 that is linked to the diaphragm 41 and increases or decreases the amount of gas supplied to the gas burner 24 according to the water flow rate. A water supply temperature compensation valve 48 that reduces the amount of displacement of the water as the temperature of the water supply increases so that hot water at a substantially constant high temperature is always obtained by the heat exchanger 16 regardless of the temperature of the water supply; The amount of water flowing to the exchanger 16 is the same as that of the gas burner 24.
A constant flow valve 60 is provided to limit the flow rate from exceeding the maximum flow rate corresponding to the maximum capacity of the water supply passage 10, and this constant flow valve is slidable in the axial direction into a fitting hole 10a formed on the inner surface of the water supply passage 10. a sliding tube 62 having an inward flange portion 62a that is fitted into the sliding tube and has an opening 62b in the center; a tapered member 65 forming a variable throttle portion 61 between the opening and the opening, and a thermally responsive member 66 located within the water supply passage 10; The structure is such that when the water supply passage 10 is biased and positioned upstream and moved downstream, the passage area of the variable throttle section 61 is reduced. It is characterized in that it is connected to the thermally responsive member 66 and is configured to move in the axial direction as the temperature of the thermally responsive member increases, thereby increasing the passage area of the variable throttle portion 61.

[Effect]

When the amount of water passing through the heat exchanger 16 is small, the sliding tube 62 of the constant flow valve 60 and the tapered member 65
Either one of them is biased and positioned by a spring 63, and the passage area of the variable throttle section 61 has a value corresponding to the water supply temperature. When the water flow reaches a predetermined maximum flow rate, either the sliding tube 62 or the tapered member 65 moves downstream against the spring 63 due to the pressure difference generated before and after the water flow at the maximum flow rate. This reduces the passage area of the variable restrictor 61, prevents the flow rate from exceeding the maximum flow rate, and prevents the temperature of the hot water from the heat exchanger 16 from dropping below a predetermined high temperature.

In a state where the feed water temperature is low, the feed water temperature compensation valve 48 increases the amount of gas supply by increasing the amount of displacement of the diaphragm 41 with respect to the amount of water flow, and the heat exchanger 16 heats the feed water to a certain high temperature. The constant flow valve 60 reduces the passage area of the variable restrictor 61 between the sliding tube 62 and the tapered member 65 by the action of the thermally responsive member 66, and sets the maximum flow rate of water flow to a small value. In this state,
When the water flow rate increases and reaches the maximum flow rate set to the small value, the constant flow valve 60 prevents a further increase in the water flow rate, and at the same time, the gas burner 24 reaches its maximum capacity. When the feed water temperature rises, the feed water temperature compensation valve 48 reduces the gas supply amount relative to the water flow rate, reduces the heating amount of the heat exchanger 16 by the increase in the feed water temperature, and heats the feed water to the same constant high temperature as described above. On the other hand, the constant flow valve 60
The passage area of the variable throttle section 61 is increased by the action of the thermally responsive member 66, and the maximum flow rate of water flow is set to a large value. In this state, if the amount of water flowing increases and reaches the maximum flow rate set to the large value, a further increase in the amount of water flowing is prevented as described above, and at the same time, the gas burner 24 reaches its maximum capacity.

[Effect of idea]

As described above, according to the present invention, even if the water supply temperature changes, hot water at a constant high temperature can always be obtained from the heat exchanger over the entire range of water flow to the heat exchanger. The temperature of hot water discharged from the tank can be accurately controlled at all times. Moreover, regardless of the temperature of the water supply, the gas burner reaches its maximum capacity at the same time as the amount of water flowing to the heat exchanger reaches the set maximum flow rate, so the gas burner can always demonstrate its maximum capacity.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the accompanying drawings.

As shown in the drawing, a diaphragm device 40 is provided in the middle of the water supply path 10 to the heat exchanger 16 heated by the gas burner 24, and this diaphragm device 40 connects the gas supply path 20 to the gas burner 24.
The opening degree of the gas valve 25 provided in the heat exchanger 16 is continuously changed according to the amount of water flowing to the heat exchanger 16.

The gas passage 20 consists of a pipe line 21, a gas introduction pipe 22, and a nozzle pipe 23, which are formed in the gas passage housing 32.
A gas valve 25 is provided inside. gas valve 25
has a valve seat 26 formed on the inner wall of the pipe line 21 and a valve body 27 that is biased by a spring 28. Normally, the opening/closing portion 27b of the valve body 27 is in contact with the valve seat 26 to open the gas valve 25. However, if the opening/closing part 27b moves to the left in the drawing against the spring 28, the opening/closing part 27b will first move away from the valve seat 26 and the gas valve 25 will be at its minimum opening, and then as it moves further to the left, the proportional part 27a will move further to the left. The opening area between the valve seat 26 and the valve seat 26 is increased, thereby increasing the opening degree of the gas valve 25 and increasing the amount of gas supplied to the gas burner 24.

The water supply passage 10 has a front half 11 on the upstream side and a rear half 1 on the downstream side with the diaphragm device 40 as the boundary.
2 and a bypass 13, each part 11, 1
2 and 13 are both primary chambers 42 of the diaphragm device.
It is opened to The front half 11 is formed by a water supply channel housing 30 and a water supply pipe 33 that are fixed to each other, and the rear half 12 and the bypass 13 are formed by a water supply channel housing 30 and a connecting pipe 14.

The space formed between the water supply channel housing 30 and the cover 31 fixed thereto is connected to both members 30, 31.
A primary chamber 42 is created by a diaphragm 41 held between
The diaphragm 4 is separated into a secondary chamber 43 and a secondary chamber 43.
1 and both chambers 42 and 43 constitute the main part of the diaphragm device 40. The secondary chamber 43 is the communication path 4
7 to the negative pressure generating part of the bench lily 46 provided in the rear half 12 of the water supply passage 10, and as described above, each part 1 of the water supply passage 10 is connected to the primary chamber 42 as described above.
One end of 1, 12, 13 is opened, and a tapered projecting member 44 fixed to the center of the diaphragm 41 is inserted into an annular member 44a provided at the opening of the bypass 13, and a diaphragm is formed between the two members 44, 44a. Part 4
5, and the rear half 12 of the water supply passage 10 is provided with a water supply temperature compensation valve 48 which is operated by a built-in thermally responsive member. The amount of water flowing to the heat exchanger 16 is distributed between the rear half 12 of the water supply passage 10 and the bypass 13 at a ratio according to the resistance of the water supply temperature compensation valve 48 and the throttle section 45, and is determined by the flow rate distributed to the rear half 12. The negative pressure generated in the bench lily 46 is transferred to the secondary chamber 4.
3 to produce an actuating force on the diaphragm 41 to the left in the drawing, and this actuating force is transmitted to the valve body 27 of the gas valve 25 by the rod 49 and the valve stem 29. If the flow rate is small, the operating force is also small, so the diaphragm 41 is not displaced and the gas valve 25 is closed. However, if the flow rate increases to a predetermined minimum flow rate (consistent with Qo described later), the diaphragm 41 resists the spring 28. and moves the valve body 27 to the left to open the gas valve 25 to the minimum opening degree and supply the minimum amount of gas necessary for stable combustion of the gas burner 24. The minimum flow rate of the water flow rate is determined so that boiling does not occur in the heat exchanger 16 when heated by combustion of this minimum amount of gas. If the amount of water flowing further increases, the diaphragm 41 deflects the spring 28 and is displaced, moving the valve body 27 and increasing the opening degree of the gas valve 25. Due to the above action, the gas burner 24
The amount of gas supplied to the heat exchanger 16 is approximately proportional to the amount of water flowing to the heat exchanger 16. Therefore, the ratio of the amount of water flow and the amount of gas supplied is set so that the temperature of the hot water supplied from the heat exchanger 16 to the mixing valve 50, which will be described later, is always at a predetermined high temperature.

The feed water temperature compensating valve 48 decreases its opening as the feed water temperature rises, lowering the distribution ratio of the amount of water flowing to the heat exchanger 16 to the rear half 12, and decreasing the opening of the gas valve 25. If the feed water temperature decreases, the opening degree of the gas valve 25 is corrected to increase, and as a result, if the feed water temperature decreases, the temperature rise of the feed water heated by the heat exchanger 16 increases. In this way, the temperature of the hot water supplied from the heat exchanger 16 to the mixing valve 50 is compensated for so as not to change. This allows the temperature of hot water discharged from the gas water heater to be accurately controlled at all times.

The supply water temperature compensation valve 48 is not limited to that of this embodiment, and the junction part of the bypass 13 with the connecting pipe 14 is provided between the bench lily 46 and the supply water temperature compensation valve 48 as shown by the chain line 13a, and the supply water temperature compensation valve 48 is The same effect can be achieved by configuring the temperature compensation valve 48 so that the degree of opening increases as the temperature of the water supply increases.

Next, the mixing valve 50 will be explained. A housing 51 of the mixing valve 50 has a mixing chamber 52 formed therein,
The mixing chamber 52 has a hot water inlet 53 that communicates with the heat exchanger 16, a cold water inlet 54 that communicates with the water supply pipe 33 on the upstream side of the diaphragm device 40 via an automatic valve 70 (described later), and an outlet that communicates with the hot water supply pipe 17. Sprue 55
is opened. A hot water valve seat 52a formed at the opening of the hot water inlet 53 and a cold water valve seat 52b formed at the opening of the cold water inlet 54 are arranged concentrically and facing each other. A valve shaft 57 is provided in the valve shaft 57 . A pair of valve bodies 56a and 56b are fixed to the valve shaft 57 with a gap in the axial direction, and are driven forward and backward in the axial direction by a servo motor 58. The servo motor 58 is controlled by a control device (not shown), and when the hot water temperature detected by a thermistor (not shown) etc. provided in the hot water supply pipe 17 is lower than the hot water temperature arbitrarily set by the user. , the valve stem 57 is moved back (moved downward in FIG. 1) to separate the valve body 56a and the hot water valve seat 5.
At the same time, the passage area between the valve body 5 and the valve body 5 is increased.
6b and the cold water valve seat 52b to increase the inflow ratio of hot water from the heat exchanger 16, thereby increasing the temperature of hot water sent from the hot water outlet 55 to the hot water supply pipe 17, and If the detected hot water temperature is higher than the set hot water temperature, the valve shaft 57 is advanced in the opposite direction to the above, and the water supply pipe 33 is opened.
The temperature of the hot water sent to the hot water supply pipe 17 is lowered by increasing the inflow ratio of cold water from the hot water supply pipe 17. The amount of hot water dispensed is changed by the user opening and closing a hot water tap (not shown) provided at the end of the hot water pipe 17.

The automatic valve 70 provided between the cold water inlet 54 of the mixing valve 50 and the water supply pipe 33 is movably supported by a valve seat member 71 having a valve port 72 and a support member 74 fixed to the valve seat member 71, and is configured to supply cold water by a spring 75. Consisting of a valve member 73 that is biased by a valve seat member 71 from the inlet 54 side and normally closes the valve port 72, the valve seat member 71
A bypass hole 76 is provided in the. When water is flowing through the heat exchanger 16, the automatic valve 7
A pressure difference occurs on both sides of the automatic valve 70 due to the resistance of the water supply passage 10 from the front side of the constant flow valve 60 to the rear side of the mixing valve 50, which will be described later.
works. That is, when the amount of water flowing into the heat exchanger 16 is less than the minimum flow rate (Qo, described later) required to maintain the minimum opening degree of the gas valve 25 necessary for stable combustion in the gas burner 24, the valve member 73 is activated by the spring 75. When the valve member 73 is energized to close the valve port 72 and the water flow rate exceeds the minimum flow rate Qo, the valve member 73 resists the spring 75 and closes the valve port 72 due to the increase in the pressure difference.
It operates to open 2. Note that even when the valve port 72 is closed, both sides of the automatic valve 70 are communicated through the thin bypass hole 76. Note that the automatic valve 70 is not limited to the structure of the above embodiment.
For example, it may be configured to close when the amount of water flowing to the heat exchanger 16 becomes equal to or less than the minimum flow rate Qo by linking with the displacement of the diaphragm 41.

A constant flow valve 60 is provided in a portion of the front half 11 of the water supply passage 10 that is formed inside the water supply channel housing 30 . The constant flow valve 60 includes a sliding tube 62 that is slidably fitted into a fitting hole 10a formed in the water supply channel housing 30 and urged upstream by a spring 63, and a sliding tube 62 that is supported concentrically with the sliding tube 62 and has a tapered shape. A tapered member 65 is provided, the tip of which is inserted into an opening 62b at the center of the inward flange portion 62a of the sliding tube 62 to form a variable throttle portion 61 between the opening 62b and the opening 62b. The root portion of the tapered member 65 is slidably supported by a guide tube 69 fixed to the water supply channel housing 30, and is biased upstream by a spring 68 interposed between the guide tube 69 and the tip thereof. It is in contact with an actuating portion 66a at the tip of a thermally responsive member 66 supported in the water supply passage 10 concentrically with the matching hole 10a. The thermally responsive member 66 is attached to the water supply channel housing 30
It is supported by a support disk 67 clipped therein, which has a communication hole through which the water supply to the heat exchanger 16 passes, and which also has a stopper of the sliding tube 62 biased by a spring 63. is forming. When the amount of water flowing into the heat exchanger 16 reaches the maximum flow rate corresponding to the maximum opening of the gas valve 25, that is, the maximum capacity of the gas burner 24, the sliding tube 62 is activated by the spring 63 due to the pressure difference generated before and after the inward flange portion 62a. The variable throttle section 61 moves downstream against the
This prevents the water flow rate from exceeding the maximum flow rate so that the hot water supplied to the hot water inlet 53 of the mixing valve 50 is always maintained at a predetermined high temperature.

Heat exchanger 16 corresponding to the maximum opening degree of gas valve 25
The maximum flow rate to the heat exchanger 16 varies depending on the temperature of the water supply, and if the maximum flow rate by the constant flow valve 60 is set based on a state where the temperature of the water supply is high, the value will be relatively large. If the maximum flow rate of water is passed, the maximum capacity of the gas burner 24 will be exceeded, so the temperature of the hot water supplied from the heat exchanger 16 to the hot water inlet 53 of the mixing valve 50 will be lower than a predetermined high temperature. Conversely, if the maximum flow rate is set based on a state where the water supply temperature is low, the value will be relatively small, and if the water supply temperature rises, the water flow rate will reach the maximum flow rate before the gas burner 24 reaches its maximum capacity. , gas burner 24
unable to demonstrate their maximum potential. In this embodiment, if the water supply temperature rises, the heat sensitive member 6
Since the actuating portion 66a at the tip of the sliding tube 62 extends and moves the tapered member 65 backward (moves downward in FIG. 1), the inward flange portion 62a of the sliding tube 62 and the tapered member 6
The opening area of the variable diaphragm section 61 between 5 and 5 is large,
This characteristic is suitable when the maximum flow rate setting is large and the supply water temperature is high. Also, if the water supply temperature decreases, the tapered member 65 moves forward, so the variable throttle part 61
The opening area is small, the set value of the maximum flow rate is small, and the characteristics are suitable when the water supply temperature is low.
In either case, as soon as the amount of water flowing to the heat exchanger 16 reaches the set maximum flow rate, the gas burner 24
reaches its maximum capacity, so the maximum capacity of the gas burner 24 is always exhibited.

[Brief explanation of drawings]

The drawing is a structural diagram of an embodiment of the gas water heater according to the present invention. Explanation of symbols, 10... Water supply passage, 10a... Fitting hole, 16... Heat exchanger, 24... Gas burner,
25...Gas valve, 40...Diaphragm device, 4
1...Diaphragm, 48...Water supply temperature compensation valve,
60... Constant flow valve, 61... Variable throttle, 62...
Sliding tube, 62a...Inward flange portion, 62b...
Opening, 63...spring, 65...tapered member, 66...thermally responsive member.

Claims (1)

[Scope of utility model registration request] A diaphragm device having a diaphragm installed in a water supply passage communicating with a heat exchanger heated by a gas burner and displaced according to the amount of water flowing to the heat exchanger; In a gas water heater equipped with a gas valve that increases or decreases the amount of gas supplied, the water supply passage is configured to reduce the amount of displacement of the diaphragm with respect to the amount of water flowing in accordance with a rise in the temperature of the water supply, regardless of the temperature of the water supply. First, there is a water supply temperature compensation valve that allows the heat exchanger to always provide hot water at a substantially constant high temperature, and a restriction that restricts the amount of water flowing to the heat exchanger from exceeding a maximum flow rate corresponding to the maximum capacity of the gas burner. A constant flow valve is provided, and the constant flow valve is fitted into a fitting hole formed on the inner surface along the water supply passage so as to be slidable in the axial direction, and has an inward flange portion with an opening in the center. a moving cylinder, a tapered member that is provided so as to be movable in the axial direction concentrically with the sliding cylinder, and a portion of which is inserted into the opening to form a variable throttle portion between the sliding cylinder and the water supply passage; one of the sliding tube and the tapered member is positioned by being biased toward the upstream side of the water supply passage by a spring, and when moved downstream, the sliding tube and the tapered member are positioned in the passage of the variable throttle section. The other of the sliding tube and the tapered member is connected to the thermally responsive member and moves in the axial direction as the temperature of the thermally responsive member increases to increase the passage area of the variable throttle portion. A gas water heater characterized by being configured as follows.