JP3932228B2 - Bypass mixing water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention connects a bypass pipe that bypasses the heat exchanger between a water supply pipe and a hot water pipe connected to the heat exchanger, and adjusts the amount of water passing through the bypass pipe to thereby remove the hot water from the heat exchanger. The present invention relates to a bypass mixing type water heater that can adjust the temperature of the hot water (heat exchange outlet temperature) to a certain temperature range without the possibility of drain generation and boiling.
[0002]
[Prior art]
In the bypass mixing type water heater, a heat responsive member such as a shape memory alloy spring is provided on the water supply pipe side or the hot water discharge pipe side to control the operation of a control valve that determines the amount of water flow (bypass rate) to the bypass pipe. It is known that drain and boiling can be prevented by changing the bypass rate according to the incoming water temperature, the outgoing hot water temperature, etc. The applicant has already provided an effective form for preventing such hunting because an unnecessary change in the rate occurs and the hot water temperature hunts. Specifically, as shown in FIG. 6, in the bypass mixing type water heater 50, a heat exchanger 52 including a burner 51 is connected with a water supply pipe 53 and a hot water discharge pipe 54, and the water supply pipe 53 and the hot water supply hot water 52. A bypass pipe 55 that bypasses the heat exchanger 52 is connected to the pipe 54. And at the connection part of the water supply pipe 53 and the bypass pipe 55, the control valve 56 which can control the water flow amount to the bypass pipe 55, the shape memory alloy spring 57 as a heat responsive member which changes a load with temperature, An opposing bias spring 58 is provided to control the stroke of the control valve 56 based on the incoming water temperature.
[0003]
On the other hand, the connecting portion of the bypass pipe 55 to the hot water pipe 54 is branched into the first passage 59 and the second passage 60 having a smaller opening area, and the hot water pipe 54 has openings 62 and 63 corresponding to the respective passages. And a sleeve 61 as a second control valve formed so as to be slidable. The sleeve 61 is supported by an upstream shape memory alloy spring 64 and a downstream bias spring 65. By forming a bypass 66 that allows water from the opening 62 to flow in from the upstream of the shape memory alloy spring 64, the shape memory alloy spring 64 is operated at a predetermined temperature so that only the first passage 59 is provided in the sleeve 61 in the low temperature range. In the high temperature range, the sleeve 61 is given a stroke that opens only the second passage 60. According to this, it is possible to adjust the bypass rate to be 41 ° C. or higher at a portion where drainage is likely to occur at the temperature in the heat exchanger, and to maintain 85 ° C. or lower without fear of boiling at the time of high temperature hot water. Since the sensed temperature of the shape memory alloy spring 64 has hysteresis between the mixing temperature and the heat exchange outlet temperature, the operation of the sleeve 61 is minimized, and an unnecessary change in the bypass rate due to the flow rate change is achieved. It is prevented and the hot water discharge characteristic is improved.
[0004]
[Problems to be solved by the invention]
The above-described structure is such that the sleeve 61 slides in the hot water outlet pipe 54, so that the sleeve 61 is likely to be fixed and poorly slid. In addition, it is difficult to accurately match the overlap of the openings 62 and 63 of the sleeve 61 with the first and second passages 59 and 60, and the shift becomes large due to the secular change of the spring load, so that proper passage switching is not performed. There is a fear. Further, the reliability of the seal with the bypass pipe 55 side by the sleeve 61 is low.
[0005]
Therefore, the invention described in claim 1 provides the two control valves and the thermally responsive member on the water inlet side and the hot water side as described above, and the second heat by switching the passage from the bypass pipe particularly on the hot water side. The purpose of the present invention is to provide a bypass mixing type water heater that can smoothly and surely switch the passage in a sensed temperature of the response member, and that is excellent in sealing performance and durability. .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a cylindrical body communicating with the bypass pipe is provided in the hot water discharge pipe along the hot water discharge pipe, and an opening on the upstream side of the cylindrical body is provided. The first valve seat is provided at the downstream opening, the second control valve is accommodated in the cylindrical body, and the first valve seat is disposed between the first valve seat and the second control valve. The second passage is formed between the second valve seat and the second control valve, respectively, while the second heat responsive member is located upstream of the second valve seat outside the cylindrical body. It is arranged on the side and connected to the second control valve.
In addition to the object of the first aspect, the second aspect of the invention provides the second control valve with a cylinder in order to satisfactorily mix the water flowing from the first passage of the cylindrical body with the hot water in the tapping pipe. A guide body is provided in a row so that the water flowing from the first passage is brought into contact with the upstream side of the shape body to flow radially into the hot water discharge pipe.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described 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 the controller 9. The controller 9 is a proportional control valve (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. Well-known hot water temperature control is performed such as controlling the opening degree (not shown).
[0008]
A bypass pipe 10 that bypasses the heat exchanger 4 is connected between the water supply pipe 2 and the hot water discharge pipe 5, and a water governor 11 is provided at a connection portion between the water supply pipe 2 and the bypass pipe 10. The water governor 11 fixes a cup-shaped fixed valve body 14 opened on the upstream side to one side (right side in FIG. 1) of a governor body 13 partitioned into two by a partition wall 12 so that the fixed valve cannot move. A movable valve body 15 is slidably provided on the inner wall of the fixed valve body 14 via a seal member 16 inside the body 14 so that the opening degree of the valve seat 17 formed on the fixed valve body 14 can be adjusted. A coil spring 18 is provided between the fixed valve body 14 and the movable valve body 15 to urge the movable valve body 15 upstream. Reference numeral 19 denotes a stopper ring that regulates the slide position of the movable valve body 15.
On the other hand, on the other side (left side in FIG. 1) of the partition wall 12 in the governor body 13, a passage 20 for water flowing into the water supply pipe 2 is formed, and the valve shaft 21 moves in the axial direction in the passage 20. A variable flow rate needle 23 is provided at the lower end of the valve shaft 21 and can adjust the opening degree of the passage 20 with the valve seat 22. The upper end of the valve shaft 21 protrudes into the bypass pipe 10 through a partition wall 24 that further divides the other side of the partition wall 12, and the valve seat 25 formed in the bypass pipe 10 is opened at the tip thereof. A bypass throttle valve 26 is provided as a control valve capable of adjusting the water flow rate to the bypass pipe 10 by adjusting the degree.
[0009]
The valve shaft 21 is provided with a shape memory alloy spring 27 as a thermally responsive member between the partition wall 24 and the flow rate variable needle 23, and the shape memory alloy spring 27 is disposed upstream of the flow rate variable needle 23. Opposing bias springs 28 are packaged. That is, when the temperature of water entering the water supply pipe 2 increases, the load of the shape memory alloy spring 27 increases, and the valve shaft 21 is pushed down so that the bypass throttle valve 26 opens the passage to the bypass pipe 10 and at the same time the variable flow rate needle 23 It moves in the direction of opening the passage 20.
Further, the partition wall 12 and the fixed valve body 14 are provided with a communication hole 29 that guides water passing through the passage 20 to the internal space of the fixed valve body 14, and the fixed valve body 14 heats water in the fixed valve body 14. Openings 30, 30 for sending out to the exchanger 4 side are provided in the partition wall 12, and openings 31 for sending a part of the water sent out from the openings 30, 30 from the upstream side of the bypass throttle valve 26 to the bypass pipe 10 are provided. .
[0010]
On the other hand, a tubular body 32 that is slightly smaller than the hot water pipe 5 is supported along the hot water pipe 5 through the tubular connecting portion 33 and connected to the bypass pipe 10 in the hot water pipe 5. The bypass pipe 10 is connected to the portion 33 so that water from the bypass pipe 10 flows into the hot water discharge pipe 5 through the continuous portion 33 and the cylindrical body 32.
In the cylindrical body 32, a first valve seat 34 is formed at the upstream opening, and a second valve seat 36 is formed by the valve seat body 35 fitted into the downstream opening. A valve shaft 37 as a second control valve is accommodated coaxially with the cylindrical body 32 so as to be movable in the axial direction, and a first passage 38 formed between the valve shaft 37 and the first valve seat 34 can be opened and closed. The first valve body 39 and the second valve body 41 capable of opening and closing the second passage 40 formed between the second valve seat 36 are formed. Here, at the position of the valve shaft 37 where the first valve body 39 closes the first valve seat 34, the second valve body 41 moves away from the second valve seat 36 and opens the second passage 40, and the second valve body At the position of the valve shaft 37 where 41 closes the second valve seat 36, the first valve body 39 is away from the first valve seat 34 and opens the first passage 38. The opening areas of both passages are set so that the first passage 38 side becomes larger.
[0011]
Further, a cup-shaped guide body 42 with an opening facing downward is connected to the upper end of the valve shaft 37 so as to cover the upstream side of the cylindrical body 32. Are formed with openings 43, 43,. In addition, a shape memory alloy spring 45 as a second thermally responsive member that changes the load according to the sensed temperature is provided between the edge on the opening side of the guide body 42 and the stepped portion 44 on the outer periphery of the cylindrical body 32. It arrange | positions with the appearance packaged by the cylindrical body 32 upstream from the channel | path 40. As shown in FIG.
On the other hand, a spring receiver 46 is fixed inside the cylindrical body 32, and a bias spring 48, which is a normal coil spring, is disposed between the spring receiver 46 and a flange 47 provided continuously with the second valve body 41. Thus, the valve shaft 37 is biased in the direction in which the second valve element 41 closes the second valve seat 36.
[0012]
As shown in the graph of FIG. 2, the shape memory alloy spring 45 has a constant load as long as the sensed temperature does not exceed 57 ° C., and the stroke of the valve shaft 37 is balanced with the bias spring 48 as shown in FIG. The open position of the passage 38 is maintained. When the detected temperature exceeds 57 ° C., the load is increased to push up the valve shaft 37, and the load is made constant at 60 ° C. due to the balance with the bias spring 48. By this operation, the first valve seat 34 is closed and the second passage 40 is opened as shown in FIG. As described above, by switching the first and second passages 38 and 40 in accordance with the stroke of the valve shaft 37, the first passage 38 is closed after the valve shaft 37 is pushed up by sensing 57 ° C. or more. Since only the two passages 40 are opened, the water from the bypass pipe 10 merges from the cylindrical body 32 through the second passage 40 as it is into the outlet pipe 5 from the downstream of the shape memory alloy spring 45, so that the shape memory The alloy spring 45 senses the heat exchange outlet temperature. On the other hand, when the temperature is less than 57 ° C., the second passage 40 is closed and only the upstream first passage 38 is opened, so that water from the bypass pipe 10 passes through the first passage 38 and the opening 43 of the guide body 42. The shape memory alloy spring 45 senses the mixing temperature because it passes through the shape memory alloy spring 45 and merges into the tapping pipe 5.
[0013]
In the water heater 1 configured as described above, the water introduced into the water supply pipe 2 first passes between the valve seat 22 in the governor body 13 and the flow rate variable needle 23 through the communication hole 29 to the fixed valve body. 14, the water in the fixed valve body 14 passes through the passage between the movable valve body 15 and the valve seat 17, and from the openings 30 and 30 of the fixed valve body 14 to the heat exchanger 4 side and the bypass pipe 10 side, respectively. Flowing. At this time, the opening of the passage 20 is changed by sensing the temperature of the water flowing through the passage 20 and changing the load of the shape memory alloy spring 27 and determining the stroke of the valve shaft 21 in balance with the bias spring 28. Accordingly, the opening between the movable valve body 15 and the valve seat 17 is also changed, and the total amount of water flowing through the water governor 11 is adjusted. At the same time, since the opening between the bypass throttle valve 26 and the valve seat 25 is also changed, the amount of water flowing into the bypass pipe 10 is thereby determined. In this embodiment, the total water amount changes from 7.27 liters / minute to 13.3 liters / minute with respect to the change of the incoming water temperature from 5 ° C. to 30 ° C., and the bypass rate is 29.2% to 45.2. % Will change.
[0014]
On the side of the hot water pipe 5, when the hot water temperature is 38 ° C. to 50 ° C., the shape memory alloy spring 45 that senses the mixing temperature in the state of FIG. 1 does not operate, and the valve shaft 37 is as shown in FIG. The bypass rate is set in the range of 29.2% to 45.2% as described above by controlling the bypass throttle valve 26 on the water governor 11 side. As a result, as shown in the graph of FIG. 4 (the number at the left end of each graph indicates the tapping temperature, and the upper left indicates the water flow path of the heat absorption pipe in the heat exchanger 4), the change in the incoming water temperature is 5 ° C to 30 ° C. Regardless, the temperature after the heat exchange temperature T _A between the endothermic tubes D-E where drain is likely to be generated can be maintained at the drain limit of 41.4 ° C. or higher. Furthermore, the thermal交出port temperature T _B exceeds the 57 ° C., the shape memory alloy spring 45 for sensing the mixing temperature, when the low temperature range of hot water temperature is 57 ° C. or less, the shape memory alloy spring 45 operates There is nothing.
[0015]
When the tapping temperature is 60 ° C. or higher, the heat exchange outlet temperature T _B is 85 ° C., which is the boiling limit, as shown in the graph of FIG. 4 when the bypass rate is set only by the bypass throttle valve 26 on the water governor 11 side. In the vicinity of or exceeding this, when the sensed temperature exceeds 57 ° C., the shape memory alloy spring 45 on the tapping side operates, and the valve shaft 37 only has the second passage 40 having a small opening area as shown in FIG. Since it moves to the open position and the amount of water flow through the bypass pipe 10 is reduced, the bypass rate is set within a small range of 11.0% to 11.9% as shown in the graph b of FIG. Thus heat交出port temperature T _B, as shown in the figure, varies in the range of tapping temperature 60 ° C. At 66.8 ℃ ~64.0 ℃, the tapping temperature 70 ℃ 78.0 ℃ ~75.4 ℃ In either case, the boiling limit of 85 ° C. or lower can be maintained. Further, if the high temperature range of not lower than 60 ° C. hot water temperature is, since the heat交出port temperature T _B is always sensed temperature 57 ° C. above the temperature of the shape memory alloy spring 45, the heat交出port temperature T _B directly where The sensing shape memory alloy spring 45 does not operate.
[0016]
As described above, in the above-described embodiment, it is possible to maintain the heat exchanger 4 at an appropriate temperature that does not cause draining and boiling by controlling the appropriate bypass rate. In particular, here, the water passage from the bypass pipe 10 to the tapping pipe 5 is branched, and the shape memory alloy spring 45 has a mixing temperature at a tapping temperature of 38 ° C. to 50 ° C., and a heat exchange outlet higher than 60 ° C. Since the valve shaft 37 switches the first and second passages 38 and 40 so that the temperature is sensed and the sensed temperature of the shape memory alloy spring 45 has hysteresis, the operation start temperature of the shape memory alloy spring 45 is changed. Can be set to a relatively high value of 57 ° C., and once the passage is switched, the valve shaft 37 is almost fixed and the operation is minimized. Therefore, even if the flow rate in the appliance changes due to changes in the opening of the faucet, etc., the heat exchange outlet temperature and mixing temperature may fluctuate, preventing unnecessary changes in the bypass rate and stabilizing the tapping temperature. Because hunting does not occur, a convenient water heater can be obtained.
[0017]
Here, since the normal valve structure in which the upper and lower first and second valve seats 34 and 36 are opened and closed by the valve shaft 37 moving in the cylindrical body 32 is adopted, the valve shaft 37 moves smoothly. In addition, the opening and closing of each passage by the valve shaft 37 can be switched reliably, resulting in a switching structure with excellent sealing performance and durability. In addition, since the shape memory alloy spring 45 is externally mounted on the cylindrical body 32, the mixing temperature after mixing can be sensed as a whole, and accurate thermal response is possible.
Furthermore, since the first passage 38 is opposed to the flow of hot water in the hot water discharge pipe 5 and is brought into contact with the guide body 42, water is allowed to flow radially from the cylindrical body 32 through the openings 43, 43. The water flowing from the first passage 38 and the hot water in the tap pipe 5 can be mixed well.
[0018]
In the above embodiment, the first valve body 39 and the second valve body 41 of the valve shaft 37 are both positioned in the cylindrical body 32, and the first and second passages 38, 40 are formed from the inside of the cylindrical body 32. The valve shaft 37 is lengthened and the first valve body 39 and the second valve body 41 are provided outside the cylindrical body 32, and both passages are opened and closed by the stroke of the valve shaft 37 from above and below. You may do it. In this case, the direction in which the load of the shape memory alloy spring and the bias spring is applied is also reversed.
In the above embodiment, the guide body 42 is provided on the valve shaft 37 separately from the first valve body 39. However, if the first valve body is moved outside the cylindrical body as described above, A structure that is integrated with the guide body by extending a flange on the single valve body is also conceivable. Furthermore, in the above embodiment, two valve bodies are provided on the valve shaft. However, if the distance between the first valve seat and the second valve seat can be shortened or the stroke of the valve shaft can be made long, the single valve body can be moved up and down. The valve seat can be opened and closed.
[0019]
【The invention's effect】
According to the first aspect of the present invention, the first passage and the second passage are provided between the first and second valve seats and the second control valve, which are formed in the upper and lower openings by providing the cylindrical body in the outlet pipe. And the second heat responsive member connected to the second control valve outside the cylindrical body, the effect of switching between the first and second passages, that is, the operation of the second heat responsive member. In addition to the effect that the start temperature can be set relatively high and its operation is minimized, and an easy-to-use water heater is obtained that suppresses hunting of the hot water temperature even for flow rate changes in the appliance. A normal valve structure in which the upper and lower first and second valve seats are opened and closed by the second control valve, so that each passage can be opened and closed smoothly and reliably, and a switching structure with excellent sealing and durability is realized. it can. Further, since the second thermal response member is provided outside the cylindrical body, the mixing temperature after mixing can be sensed as a whole, and accurate thermal response is possible.
According to the second aspect of the present invention, in addition to the effect of the first aspect, water flowing from the first passage is brought into contact with the second control valve on the upstream side of the cylindrical body, and flows out radially into the tap pipe. By providing the guide body to be continuously provided, the water from the first passage and the hot water of the tapping pipe can be mixed well.
[Brief description of the drawings]
FIG. 1 is a schematic view of a bypass mixing type water heater (on the side of a hot water, an open state of a first passage 38).
FIG. 2 is a graph showing the relationship between the temperature and load of the shape memory alloy spring 45;
FIG. 3 is a schematic view of a bypass mixing type water heater (on the hot water side, the second passage 40 is opened).
FIG. 4 is a graph showing the relationship between the incoming water temperature, the heat exchange outlet temperature, and the bypass rate.
FIG. 5 is a graph showing the relationship between the incoming water temperature, the heat exchange outlet temperature, and the bypass rate.
FIG. 6 is a schematic view of a bypass mixing type water heater according to the prior application of the present applicant.
[Explanation of symbols]
1 .... Bypass mixing type water heater, 2 .... Water supply pipe, 3 .... Gas burner, 4 .... Heat exchanger, 5 .... Hot water pipe, 8 .... Hot water temperature sensor, 9 .... Controller, 10 .... Bypass pipe , 11 .. Water governor, 14 .. Fixed valve body, 15 .. Movable valve body, 21, 37 .. Valve shaft, 23 .. Variable flow needle, 26 .. Bypass throttle valve, 27, 45. Alloy springs 28, 48... Bias springs 32.. Cylindrical body 34.. First valve seat 36 36 Second seat 38 38 First passage 39 First valve body 40 .. Second passage 41.. Second valve body 42.. Guide body

Claims (2)

A heat exchanger provided with a burner that varies the amount of combustion according to the required amount of heat; a water supply pipe that supplies water to the heat exchanger; and a hot water discharge pipe that delivers hot water from the heat exchanger, the water supply pipe A bypass pipe that bypasses the heat exchanger, and a control valve capable of controlling the amount of water flow to the bypass pipe at a connection portion between the bypass pipe and the water supply pipe, A heat responsive member that operates according to the temperature of water entering the water supply pipe and interlocks the control valve is provided, and a first passage that opens the connection portion between the bypass pipe and the hot water pipe to the upstream side and the second passage. A second control valve capable of opening and closing each of the first passage and the second passage; and a second control valve that operates according to a temperature. A second heat responsive member to be interlocked, and at a predetermined temperature of the second heat responsive member. By the operation, only the first passage is opened to the second control valve in the low temperature region than the predetermined temperature, and only the second passage is opened to the second control valve in the high temperature region than the predetermined temperature. By the operation control of the first and second control valves by the second heat responsive member, a bypass mixing type water heater capable of adjusting the amount of water flow to the bypass pipe,
A tubular body communicating with the bypass pipe is provided in the hot water pipe along the hot water pipe, and a first valve seat is provided at the upstream opening of the tubular body, and a second valve seat is provided at the downstream opening. Providing the second control valve in the cylindrical body, and connecting the first passage between the first valve seat and the second control valve between the second valve seat and the second control valve. Each of the second passages is formed therebetween, and the second thermally responsive member is disposed on the upstream side of the second valve seat outside the cylindrical body and connected to the second control valve. Bypass mixing type water heater. The bypass mixing type water heater according to claim 1, wherein a guide body is provided continuously with the second control valve so that water flowing from the first passage is brought into contact with the second control valve on the upstream side to flow radially into the hot water discharge pipe.

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