JP3936800B2 - Bypass mixing water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a bypass pipe that bypasses the heat exchanger is connected between a water supply pipe and a hot water pipe connected to the heat exchanger, and the amount of water from the bypass pipe is controlled by a control valve provided at a connection portion with the hot water pipe. It is related with the bypass mixing type water heater which made it possible to control the inner cylinder exit temperature from a heat exchanger to the predetermined range by controlling.
[0002]
[Prior art]
In the above-mentioned bypass mixing type water heater, a control valve is provided at the water outlet from the bypass pipe to the outlet pipe, and the stroke of the control valve is the temperature after mixing the water from the bypass pipe with the hot water from the heat exchanger. By controlling the balance between a shape memory alloy spring as a thermally responsive member that changes the spring constant according to (hereinafter referred to as “mixing temperature”) and a bias spring arranged opposite to the shape memory alloy spring, to the instrument By adjusting the ratio of the flow rate of the bypass pipe to the total flow rate (bypass rate), the inner cylinder outlet temperature from the heat exchanger is brought to a boiling point from the lower limit temperature (for example 47 ° C) that does not generate drainage in the heat exchanger. It can be controlled within the range of the upper limit temperature (for example, 85 ° C.).
FIG. 3B shows a case where the set temperature is 50 ° C., and changes in the inner trunk outlet temperature T ₁ during hot water supply, the mixing temperature T ₂ sensed by the shape memory alloy spring, and the tapping temperature T ₃ from the appliance are shown. The shape memory alloy spring having an operation start temperature of 53 ° C. is used, and by this operation, the bypass rate is adjusted to be 10% at 53 ° C. or higher and 40% at 53 ° C. or lower. .
[0003]
[Problems to be solved by the invention]
In the graph of the figure, for example, when the flow rate in the appliance decreases due to, for example, a change in the opening of the faucet by the user (point a), the inner trunk outlet temperature T ₁ rises even if the bypass rate does not change, and the mixing temperature T ₂ raising the or tapping temperature T ₃ may become. For this reason, when the mixing temperature T ₂ reaches 53 ° C., the shape memory alloy spring reacts to interlock the control valve, and the bypass rate becomes 10%, so that the flow rate on the heat exchanger side increases. However, due to the piping length from the water supply pipe through the heat exchanger to the bypass pipe connection port of the hot water pipe, the inner cylinder outlet temperature T ₁ due to the increase in the flow rate can be reduced even if the bypass rate decreases immediately in conjunction with the control valve. Since a time lag occurs before the effect of the decrease appears, the mixing temperature T ₂ and the tapping temperature T ₃ rise even after the elapse of the point b, and are delayed from the vicinity of the point c where the effect of the decrease in the inner trunk outlet temperature T ₁ appears. Start to descend. Then, at the point d when the mixing temperature T ₂ drops to 53 ° C., the shape memory alloy spring is actuated to open the control valve and increase the bypass rate to 40%. The inner cylinder outlet temperature T ₁ is decreased and the inner cylinder outlet temperature T ₁ is increased. In this case, the mixing temperature T ₂ and the tapping temperature T ₃ are d points due to a delay in timing when the influence of the increase in the inner cylinder outlet temperature T ₁ due to the decrease in the flow rate appears. It continues to descend after the lapse of time, and falls below the set temperature at the point e.
Thereafter, as the inner trunk outlet temperature T ₁ rises, the mixing temperature T ₂ and the tapping temperature T ₃ are reversed and rise, and the control valve is closed again at 53 ° C. (point f), and the bypass rate becomes 10%. Even if it becomes like this, since the influence of the fall of the inner trunk outlet temperature T ₁ due to the increase in the flow rate is delayed similarly to the point b, the mixing temperature T ₂ and the tapping temperature T ₃ continue to rise and greatly exceed the set temperature. Then, after the inner trunk outlet temperature T ₁ starts to decrease due to the increase in flow rate, the mixing temperature T ₂ and the tapping temperature T ₃ begin to decrease with a delay.
As described above, the inner cylinder outlet temperature T ₁ once changes due to the flow rate change depending on the use situation or the like, and the shape memory alloy spring reacts to change the bypass rate unnecessarily, resulting in hunting of the tapping temperature T _3. It has become.
[0004]
Accordingly, an object of the invention described in claim 1 is to provide a bypass mixing type water heater that eliminates an unnecessary change in the bypass rate due to such a change in flow rate and enables stable hot water temperature control. Is.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is characterized in that an interlocking plate fixed to the end of the valve shaft is connected to the valve body of the control valve by connecting the valve shaft protruding into the tap pipe. The shape memory alloy spring and the coil spring arranged opposite to each other are clamped, and the valve body is interlocked with the operation of the shape memory alloy spring, while a stopper is provided around the valve shaft and orthogonal to the valve shaft. A motion control plate that is loosely formed in the shape and is urged to a contact position with the stopper is provided, and the motion control plate is related to contact with the stopper and a through hole that is closed at the contact position with the stopper. Open communication holes are formed, and when the valve body moves in the valve closing direction, the stopper moves away from the operation control plate to open the through hole, thereby allowing the valve shaft to follow the movement of the shape memory alloy spring. To quickly move the valve body in the valve closing direction while moving the valve body in the valve opening direction. By closing the through-hole with a stopper, the operation control plate is subjected to hot water resistance to delay the operation of the valve shaft with respect to the operation of the shape memory alloy spring, so that the valve body reaches a predetermined opening degree. It is characterized by being delayed .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an outline of a bypass mixing type water heater (hereinafter abbreviated as “water heater”). The water heater 1 supplies a water supply pipe 2 connected to a water supply and water guided from the water supply pipe 2 to a gas burner. 3 is provided with a heat exchanger 4 that is heated by 3 and a hot water outlet pipe 5 that delivers hot water heated by the heat exchanger 4. Further, the water supply pipe 2 is provided with a water amount sensor 6 for detecting the amount of water and a water incoming temperature sensor 7 for detecting the incoming water temperature, and the hot water outlet pipe 5 is provided with a hot water temperature sensor 8 for detecting the hot water temperature. It is connected to a controller (not shown). This controller is a proportional control valve (not shown) provided in the gas flow path to the gas burner 3 so that the hot water is discharged at a temperature set by the user based on detection signals obtained from the incoming water temperature sensor 7 and the outgoing water temperature sensor 8. Z)).
[0007]
A bypass pipe 9 that bypasses the heat exchanger 4 is connected between the water supply pipe 2 and the hot water pipe 5, and a valve unit 10 is formed at a connection portion between the bypass pipe 9 and the hot water pipe 5. Yes. The valve unit 10 forms a water passage 12 extending from a water outlet 13 from the bypass pipe 9 to a valve seat 14 opened in the hot water pipe 5 in a cylindrical unit body 11 that is slightly smaller than the hot water pipe 5. A valve body 15 capable of opening and closing the water passage 12 is disposed in the valve seat 14. Further, the valve body 15 is connected to a valve shaft 16 that penetrates the partition wall 17 that partitions the water passage 12 and extends below the unit body 11, and a disk-like interlocking plate 18 is fixed to the lower end of the valve shaft 16 in an orthogonal shape. is doing. Further, a shape memory alloy spring 20 as a thermally responsive member whose upper end is locked to the spring receiver 19 is located above the interlocking plate 18, and a lower end is locked to the spring receiver 21 below the interlocking plate 18. Bias springs 22, which are ordinary coil springs, are arranged, and the interlocking plate 18 is supported by the balance between the shape memory alloy spring 20 and the bias spring 22. In addition, a hot water inlet 23 is formed at the side of the shape memory alloy spring 20 in the unit main body 11, while a hot water outlet 24 is formed at the lower end of the unit main body 11, so that the hot water in the hot water outlet pipe 5 is united. It can pass through the body 11.
[0008]
On the other hand, an operation control plate 25 as a resistor is disposed below the partition wall 17 in the unit main body 11. As shown in FIG. 2, the operation control plate 25 has a disk shape slightly smaller than the inner diameter of the unit main body 11, and is loosely penetrated perpendicularly to the valve shaft 16 so as to partition the inside of the unit main body 11. The coil spring 26 is disposed between the lower end of the valve shaft 16 and the lower end of the valve shaft 16 is normally in contact with the stopper 27. Be regulated. Further, a plurality of through holes 28, 28... Are radially provided around the portion where the valve shaft 16 penetrates the operation control plate 25. The through holes 28, 28,... Are positioned and sized so as to be completely closed by the stopper 27 so as to be smaller than the area of the opposing stopper 27, that is, at the lower limit position of the operation control plate 25. Furthermore, a communication hole 29 is formed in an open state at a position where the contact portion with the stopper 27 is avoided in the operation control plate 25.
[0009]
In the water heater 1 configured as described above, the hot water heated by the heat exchanger 4 and fed into the hot water discharge pipe 5 is supplied from the bypass pipe 9 through the water passage 12 into the hot water discharge pipe 5. After being mixed, it enters the unit body 11 from the hot water inlet 23. Then, the shape memory alloy spring 20 changes the spring constant according to the mixing temperature, determines the stroke of the interlocking plate 18, that is, the valve shaft 16 at a position balanced with the bias spring 22 on the opposite side, and the valve by the valve body 15. The opening degree of the seat 14, that is, the bypass rate is determined. Here, the operation start temperature of the shape memory alloy spring 20 is set to 53 ° C., and when the mixing temperature becomes 53 ° C. or more, the shape memory alloy spring 20 expands and pushes down the valve body 15 together with the valve shaft 16. When the opening degree is made small or closed, the bypass rate is set to 10% or less, and when the mixing temperature falls below 53 ° C., the shape memory alloy spring 20 contracts and pushes up the valve body 15 together with the valve shaft 16, The opening degree of the seat 14 is increased and the bypass rate is set to 40% or more. In this way, the inner cylinder outlet temperature from the heat exchanger 4 can be adjusted to a range (for example, a range of 47 ° C. to 85 ° C.) that does not generate drain or boil.
The operation control plate 25 passes hot water from the stopper 27 and the operation control plate 25 through the through holes 28, 28,... Therefore, the valve shaft 16 and the operation control plate 25 are lowered following the extension of the shape memory alloy spring 20 to quickly close the valve seat 14. On the other hand, when the valve shaft 16 is pushed up, that is, when the valve shaft 16 is pushed up, the lower surfaces of the through holes 28, 28... Of the operation control plate 25 are closed by the stopper 27 and the upper and lower sides of the operation control plate 25 are communicated only by the communication hole 29. Even if the operation control plate 25 receives the resistance of hot water to delay the rise of the valve shaft 16 and starts to operate in conjunction with the shape memory alloy spring 20, it takes time to reach the predetermined valve opening position. The operation of the shape memory alloy spring 20 is delayed.
[0010]
The effect of delaying the completion of the operation to the predetermined opening by the operation control plate 25 will be described with reference to the graph of FIG. Similarly to the graph in FIG. 5B, the flow rate inside the appliance decreases at point a due to the change of the opening of the faucet by the user, etc., so that the inner trunk outlet temperature T ₁ rises with the bypass rate unchanged. When the mixing temperature T ₂ and the tapping temperature T ₃ (the mixing temperature T ₂ and the tapping temperature T ₃ change substantially in synchronism with each other, only the tapping temperature T ₃ is shown here), the operation start temperature (53 ° C.) is increased. The shape memory alloy spring 20 operates at the point b that reaches the value, and the valve body 15 quickly moves in the valve closing direction to change the bypass rate to 10%. Therefore, the flow rate to the heat exchanger 4 increases and the inner cylinder outlet temperature T ₁ starts to decrease. Also in this case, since the time delay occurs until the influence of the decrease in the inner trunk outlet temperature T ₁ due to the increase in the flow rate is transmitted to the shape memory alloy spring 20, the mixing temperature T ₂ and the tapping temperature T ₃ increase even after the point b has elapsed. The descent starts near the point c where the influence appears. Then, at the point d where the mixing temperature T ₂ drops to 53 ° C., the valve body 15 moves in the valve opening direction by the operation of the shape memory alloy spring 20 to increase the bypass rate to 40%. Since the valve element 15 is gradually opened by the resistance of the operation control plate 25, the flow rate to the heat exchanger 4 is gradually reduced. Therefore, the rising gradient after the inversion of the inner trunk outlet temperature T ₁ also becomes gentle. On the other hand, the hot water temperature T ₃ also falls gently, so that it does not drop until it falls below the set temperature, and the inner trunk outlet temperature T ₁ does not rise rapidly, so that the reverse rise of the hot water temperature T ₃ does not occur. Therefore, the mixing temperature T ₂ and the tapping temperature T ₃ are maintained at the set temperatures as they are. Further, the inner cylinder outlet temperature T ₁ is also stabilized within the boiling limit.
[0011]
Thus, according to the above embodiment, even if the change in the flow rate change, etc. usage occurs, by gradually opening the valve body 15 by the operation control panel 25, the inner cylinder outlet temperatures T ₁ and mixing A sudden change from the temperature T ₂ is eliminated, and there is no significant shift in the timing of the temperature change between the two, thereby preventing an unnecessary change in the bypass rate. Therefore, the hot water temperature T ₃ is stable, hunting does not occur, and a user-friendly water heater can be configured. Further, by adopting the operation control plate 25, it is possible to easily realize an operation delay in the valve opening direction.
[0012]
The movement speed of the operation control plate 25 can be adjusted as appropriate depending on the size of the communication hole 29. For example, a slide plate that can open or close the large communication hole stepwise or steplessly is provided. Another formed adjustment plate may be overlapped on the same axis, and the opening area may be adjusted by shifting the overlap of the through-holes by rotating the adjustment plate, so that the time required to open the valve can be easily changed.
[0013]
【The invention's effect】
According to the first aspect of the present invention, the operation control plate delays the arrival of the valve body of the control valve to the predetermined opening even if the usage state such as a flow rate change may occur. In addition, there is no sudden change between the inner cylinder outlet temperature and the mixing temperature, and there is no significant shift in the temperature change timing between the two, thereby preventing an unnecessary change in the bypass rate. Therefore, the hot water temperature is stable, hunting does not occur, and a user-friendly water heater can be configured. In particular, the operation delay of the valve body can be easily realized by adopting the operation control plate .
[Brief description of the drawings]
FIG. 1 is a schematic view of a bypass mixing type water heater.
FIG. 2 is an explanatory view of an operation control plate as viewed from below.
FIG. 3 (A) is a graph showing a temperature change in the instrument in the above embodiment.
(B) It is a graph which shows the temperature change in the instrument in the conventional water heater.
[Explanation of symbols]
1 .... Bypass mixing water heater, 2 .... Water supply pipe, 3 .... Gas burner, 4 .... Heat exchanger, 5 .... Hot outlet pipe, 9 .... Bypass pipe, 10 .... Valve unit, 11 .... Unit body , 12..Water passage, 14 .... Valve seat, 15 .... Valve body, 16 .... Valve shaft, 20 .... Shape memory alloy spring, 22 .... Bias spring, 25 ... Operation control plate, 29 ... Communication Hole.

Claims (1)

A heat exchanger provided with a burner, a water supply pipe for supplying water to the heat exchanger, and a hot water pipe for sending out hot water heated by the heat exchanger, while being provided between the water supply pipe and the hot water pipe A bypass pipe that bypasses the heat exchanger, and a control valve capable of controlling the amount of water from the bypass pipe at a connecting portion between the bypass pipe and the hot water pipe, and the temperature of the hot water in the hot water pipe A shape memory alloy spring that operates in response to the valve body of the control valve, and the amount of water from the bypass pipe to the tapping pipe can be adjusted by opening and closing control of the control valve by the shape memory alloy spring. Bypass mixing type water heater
A valve shaft protruding into the hot water discharge pipe is connected to the valve body, and an interlocking plate fixed to the end of the valve shaft is sandwiched between the shape memory alloy spring and the coil spring arranged opposite to each other. , While interlocking the valve body to the operation of the shape memory alloy spring,
A stopper is provided at an intermediate position of the valve shaft, and an operation control plate is provided which is oscillated perpendicularly to the valve shaft and biased to a contact position with the stopper. A through hole that is closed at the contact position with the stopper and a communication hole that is open regardless of the contact with the stopper are formed, respectively.
When the valve body is moved in the valve closing direction, the stopper is separated from the operation control plate to open the through hole, thereby causing the valve shaft to follow the operation of the shape memory alloy spring. While moving quickly in the valve closing direction, when the valve body moves in the valve opening direction, the through hole is closed by the stopper, so that the operation control plate is subjected to hot water resistance to operate the valve shaft. Is delayed with respect to the operation of the shape memory alloy spring, and the valve body is delayed from reaching a predetermined opening degree .

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