JP2011226697A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater suppressing attachment of scale to the inner face of a pipe.SOLUTION: The water heater includes a heating source for heating water to obtain the water of high temperature, and a scale removing device 28 disposed on the way of a flow channel of the water of high temperature flowing out of the heating source. The scale removing device 28 has a scale precipitating member 29 having shape-memory effect for recovering the prescribed memorized shape at a temperature higher than the prescribed shape recovery temperature which is higher than the temperature of the water of high temperature flowing out of the heating source, a temperature rising means for rising the temperature of the scale precipitating member 29 to a temperature higher than the shape recovery temperature, and a scale accumulating part 35 for accumulating the scale S precipitated and attached to a surface of the scale precipitating member 29 when the temperature of the scale precipitating member 29 rises, and separating from the scale precipitating member 29 when the temperature rise stops and the scale precipitating member 29 deforms into the shape other than the memorized shape.

Description

  The present invention relates to a water heater provided with a scale removing device.

  In the water heater, the hardness component contained in the hot water is deposited and adhered to the inner surface of the pipe as a solid component such as calcium carbonate. Generally, such deposit deposits are called scales. There is a problem in that the scale is accumulated and the inner diameter of the piping is reduced, so that the hot water efficiency is deteriorated.

  Japanese Patent Application Laid-Open No. 11-153373 discloses a technique in which a shape memory plate is disposed on an ice making surface in an ice making machine, and the formed ice layer is peeled by changing the temperature to deform the shape memory plate. ing.

JP-A-11-153373

  The method for preventing the scale from adhering to the inner surface of the pipe of the water heater has not been sufficiently established, and the development of an effective method is desired.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a water heater that can suppress the adhesion of scale to the inner surface of a pipe.

  A water heater according to the present invention is a water heater provided with a heating source that heats water to form high-temperature water, and a scale removing device that is provided in the middle of a flow path of high-temperature water flowing out from the heating source, The scale removing device includes a scale depositing member having a shape memory effect that recovers to a predetermined memory shape when the temperature is higher than a predetermined shape recovery temperature that is higher than the temperature of the high-temperature water flowing out from the heating source, and the scale depositing member. A temperature raising means for raising the temperature of the material to a temperature equal to or higher than the shape recovery temperature, and when the scale depositing member is heated by the temperature raising means, it is deposited and adhered to the surface of the scale depositing member. And a scale accumulating unit that accumulates the scales separated from the scale depositing member when the temperature is stopped and the scale depositing member is deformed into a shape other than the memory shape.

  According to the present invention, the hardness component in the high-temperature water flowing out from the heating source can be efficiently removed, and the scale can be prevented from adhering to the inner surface of the pipe.

It is a circuit block diagram which shows Embodiment 1 of the water heater of this invention. It is sectional drawing of the scale removal apparatus in Embodiment 1 of this invention. It is sectional drawing of the scale removal apparatus in Embodiment 1 of this invention. It is sectional drawing of the scale removal apparatus in Embodiment 2 of this invention. It is sectional drawing of the scale removal apparatus in Embodiment 2 of this invention. It is sectional drawing of the scale removal apparatus in Embodiment 3 of this invention. It is sectional drawing of the scale removal apparatus in Embodiment 3 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a circuit configuration diagram showing Embodiment 1 of a water heater according to the present invention. FIG. 1 shows an example in which the present invention is applied to a heat pump hot water supply apparatus. The heat pump hot water supply apparatus according to the present embodiment includes a heat pump unit 1 and a tank unit 2. The heat pump unit 1 has a heat pump cycle configured by connecting a compressor 3, a radiator 4, an expansion valve 5 and an evaporator 6 in order by a pipe 7. The radiator 4 functions as a heating source that heats water with the high-temperature refrigerant compressed by the compressor 3 to form high-temperature water. The heat pump unit 1 preferably uses carbon dioxide, which is a natural refrigerant, as a refrigerant, and operates on a high pressure side in a state exceeding the critical pressure.

  The tank unit 2 includes a hot water storage tank 10 and a heat exchanger 11 for bathing. The hot water storage tank 10 is a stacked hot water storage tank in which high temperature water and low temperature water are separately stored in an upper layer and a lower layer. The inside of the hot water storage tank 10 is always maintained in a full water state by the upper layer high temperature water and the lower layer low temperature water.

  The hot water storage tank 10 is provided with a high temperature water outlet 101 and a high temperature water inlet 103 at the top, and a low temperature water inlet 102 and a low temperature water outlet 104 at the bottom. The low temperature water derived from the low temperature water outlet 104 at the lower part of the hot water storage tank 10 is sent to the radiator 4 of the heat pump unit 1 by the boiling water pump 19 through the pipe 20 and is heated by the radiator 4 to a high temperature. It becomes water. The high temperature water that has exited the radiator 4 passes through the pipe 21 and is returned to the hot water storage tank 10 from the high temperature water inlet 103 at the top of the hot water storage tank 10 and stored. A heating circulation circuit is configured by the water pump 19 for boiling, the pipe 20, the radiator 4 and the pipe 21. A scale removing device 28 to be described later is installed in the heat pump unit 1 in the middle of the pipe 21 through which the high-temperature water exiting the radiator 4 flows.

  The mixing valve 23 and the mixing valve 24 are set by the user by controlling the mixing ratio between the hot water discharged from the hot water outlet 101 and the low-temperature water supplied from a water source such as tap water (city water). It is configured to produce hot water at a hot water temperature. The hot water produced by the mixing valve 23 is supplied to the bathtub 15 through the water injection pipe 26, the bathtub return pipe 17, and the bathtub outlet pipe 18. The hot water produced by the mixing valve 24 is supplied to a hot water supply port 27 such as a faucet. When hot water in the hot water storage tank 10 is discharged from the upper high temperature water outlet 101, the same amount of low temperature water supplied from the water source is introduced into the hot water storage tank 10 from the lower low temperature water inlet 102.

  The heat exchanger 11 is a water-water heat exchanger in which a water flow is opposed to each other. A tank side inlet 111 and a bath side outlet 114 are provided in the upper part, and a tank side outlet 112 and a bath side inlet 113 are provided in the lower part. Yes. High temperature water is supplied to the tank side inlet 111 at the top of the heat exchanger 11 from the high temperature water outlet 101 at the top of the hot water storage tank 10 through the pipe 12. This high-temperature water exchanges heat with bathtub water in the heat exchanger 11 to become medium-temperature water, and is discharged from the lower tank side outlet 112. The discharged medium temperature water is returned to the hot water storage tank 10 through the pipe 14 by the tank-side water supply pump 13. Bath water from the bathtub 15 is supplied to the bath-side inlet 113 at the lower part of the heat exchanger 11 through the bathtub return pipe 17 by the bath-side water supply pump 16, and heat is exchanged by the heat exchanger 11 to be heated. . The heated bathtub water discharged from the upper bath-side outlet 114 is returned to the bathtub 15 through the bathtub outlet pipe 18.

  2 and 3 are cross-sectional views of scale removing device 28 according to Embodiment 1 of the present invention. FIG. 2 shows a state when the heat pump unit 1 is operated and high-temperature water from the radiator 4 is flowing in the pipe 21 (hereinafter referred to as “boiling operation”). The high-temperature water from the radiator 4 passes through the scale removing device 28 installed in the middle of the pipe 21. As shown in FIG. 2, the scale removing device 28 in the present embodiment includes a scale depositing member 29 installed inside a flow path 36 inserted in the middle of the pipe 21. The scale depositing member 29 is made of a material having a shape memory effect, and stores a predetermined memory shape. As a material having a shape memory effect, for example, a shape memory alloy such as a Ni—Ti alloy, a Cu—Zn—Al alloy, or a Fe—Mn—Si alloy can be used.

  The scale depositing member 29 in the present embodiment has a strip-like corrugated shape, and the elongated shape shown in FIG. 2 is a memory shape. After the scale depositing member 29 is deformed at a low temperature, when the temperature becomes equal to or higher than a predetermined shape recovery temperature (transformation temperature), the scale precipitation member 29 spontaneously recovers to the memory shape. The shape recovery temperature of the scale depositing member 29 is set to a temperature (for example, a temperature higher by about 5 degrees) than the temperature of the high-temperature water flowing out from the radiator 4 (for example, 65 ° C. to 90 ° C.). In the present embodiment, a plurality of scale deposition members 29 are installed side by side.

  In addition, the shape of the scale depositing member 29 is not limited to the corrugated shape as illustrated, and may be, for example, a coil shape. Further, the scale depositing member 29 may be constituted by a net-like member instead of a plate-like member.

  In the vicinity of the scale depositing member 29, a heater 30 is provided as a temperature raising means for raising the temperature of the scale depositing member 29. During the boiling operation, the scale depositing member 29 is heated to the shape recovery temperature or higher by the heater 30. The hardness component contained in the high-temperature water is more likely to precipitate as the temperature is higher. For this reason, as shown in FIG. 2, during the boiling operation, hardness components such as calcium carbonate and magnesium contained in the high-temperature water flowing through the flow path 36 are selectively deposited on the surface of the scale deposition member 29 having a high temperature. To form a scale S.

  Below the scale depositing member 29, a scale accumulating portion 35 that forms a space is provided, and the flow is stagnant in the scale accumulating portion 35. A support member 37 is installed at the entrance of the scale accumulating unit 35. The lower end portion of the scale depositing member 29 is supported by the support member 37. The support member 37 has a shape (for example, a lattice shape) having a gap through which the scale S peeled from the scale deposition member 29 can pass.

  A weight (weight) 31 as a deformation means for deforming the scale depositing member 29 is installed on the scale depositing member 29. The weight of the weight 31 is weaker than the shape recovery force exerted by the scale depositing member 29 when the weight becomes equal to or higher than the shape recovery temperature, and when the temperature is lower than the shape recovery temperature, the scale depositing member 29 is removed. It is set so that a force of a magnitude that can be deformed is applied to the scale depositing member 29. As described above, during the boiling operation, the scale depositing member 29 is heated to the shape recovery temperature or higher by the heater 30. For this reason, the shape recovery force of the scale precipitating member 29 overcomes the weight of the weight 31, and the scale precipitating member 29 retains the memory shape (extended shape).

  FIG. 3 shows a state after the boiling operation is stopped. When the boiling operation is stopped and the circulation of water in the heating circuit including the pipe 21 is stopped, the heating by the heater 30 is also stopped. Then, the temperature of the high temperature water in the flow path 36 gradually decreases, and the temperature of the scale depositing member 29 also gradually decreases. When the temperature of the scale depositing member 29 is lowered to a temperature lower than the shape recovery temperature, the scale depositing member 29 can withstand the weight of the weight 31 and retain the memory shape (the elongated shape), as shown in FIG. It becomes impossible to be pushed from above by the weight 31 and deformed into a bent shape. The scale S is peeled off from the surface of the scale depositing member 29 by a mechanical (physical) action due to this deformation. The peeled scale S sinks downward and accumulates at the bottom of the scale accumulating portion 35 through the gap between the support members 37.

  When the boiling operation is started from the state shown in FIG. 3 and the scale depositing member 29 is heated to the shape recovery temperature or higher by the heater 30, the shape recovery force of the scale depositing member 29 overcomes the weight of the weight 31; The scale depositing member 29 returns to the memory shape (extended shape) shown in FIG. Even when high-temperature water is flowing through the flow path 36 during the boiling operation, since the flow is stagnant inside the scale accumulating unit 35, the scale S after peeling that is accumulated at the bottom of the scale accumulating unit 35 is generated. There is no flow out to the pipe 21 on the downstream side of the scale removing device 28.

  According to the scale removing device 28 as described above, the hardness component contained in the high-temperature water flowing out from the radiator 4 can be efficiently removed. For this reason, it can suppress reliably that a scale adheres to inner surfaces, such as the piping 21 and the hot water storage tank 10. FIG.

  Further, according to the scale removing device 28 of the present embodiment, the scale depositing member 29 is automatically deformed by the weight of the weight 31 when the temperature of the scale depositing member 29 is lowered, and the scale S is peeled off. it can. Therefore, an actuator for deforming the scale depositing member 29 is unnecessary, the mechanism is simple, the operation is reliable, and the manufacturing cost is low.

  In the scale removing device 28, it is preferable to provide a coating layer made of a material (for example, PTFE: polytetrafluoroethylene) having a function of preventing adhesion of scale on the surface of the flow path 36, etc. It is preferable not to provide such a coating layer on the surface of the precipitation member 29. By covering the surface other than the scale depositing member 29 with the coating layer, the scale S can be deposited and adhered more selectively only on the surface of the scale depositing member 29. The covering layer is preferably provided also on the surfaces of the weight 31 and the support member 37 and the surface of the scale accumulating portion 35.

  In the present embodiment, the scale depositing member 29 is deformed by the weight of the weight 31 when the temperature of the scale depositing member 29 decreases. However, the memory shape at the time of high temperature (first memory shape) and Is stored in the scale depositing member 29 as a memory shape at a low temperature, and the scale depositing member 29 spontaneously deforms from the first memory shape to the second memory shape at a low temperature. Sometimes, the scale depositing member 29 may be configured to spontaneously deform from the second memory shape to the first memory shape. In such a configuration, a deformation means such as the weight 31 is not necessary.

Embodiment 2. FIG.
Next, the second embodiment of the present invention will be described with reference to FIG. 4 and FIG. 5. The description will focus on the differences from the first embodiment described above, and the same or corresponding parts will be denoted by the same reference numerals. The description is omitted.

  4 and 5 are cross-sectional views of the scale removing device 28 according to the second embodiment. FIG. 4 shows a state during the boiling operation. As shown in FIG. 4, in the scale removing device 28 of the present embodiment, a connecting member 38 is installed at the upper end portion of the scale depositing member 29. On the upper part of the connecting member 38, the lower ends of the same number of metal springs 32 as the scale depositing members 29 are fixed. The upper end of the spring 32 is fixed to the ceiling of the flow path 36. Each scale depositing member 29 and each spring 32 are electrically connected inside the connecting member 38. Of the four springs 32 in the figure, a current applying electric wire 34 as an energizing means is connected to the upper end of the leftmost spring 32 and the upper end of the rightmost spring 32. Further, the upper ends of the two springs 32 at the center are electrically connected to each other. Further, among the four scale depositing members 29 in the figure, the lower ends of the two left scale depositing members 29 are electrically connected, and the lower ends of the two right scale depositing members 29 are electrically connected. Connected. With such a configuration, when a current is applied by the current application wire 34, a current flows through the scale depositing member 29 and the spring 32. When the current flows, the scale depositing member 29 and the spring 32 themselves generate heat due to Joule heat, and the temperature is higher than the shape recovery temperature of the scale depositing member 29 and is, for example, 10 times higher than the temperature of the high-temperature water flowing out of the radiator 4. The temperature is raised to a high temperature.

  The hardness component in the high temperature water is selectively deposited on the surface of the scale depositing member 29 and the spring 32 having a high temperature, and adheres as the scale S. A coating layer such as PTFE is preferably provided on the inner surface of the scale removing device 28 other than the surfaces of the scale depositing member 29 and the spring 32. Thereby, the scale S can be more selectively attached to the surfaces of the scale depositing member 29 and the spring 32.

  The urging force of the spring 32 is a force weaker than the shape recovery force exhibited by the scale depositing member 29 when the temperature becomes equal to or higher than the shape recovery temperature, and deforms the scale depositing member 29 when the temperature is lower than the shape recovery temperature. It is set so that a force of such a magnitude that can be applied to the scale depositing member 29 is applied. During the boiling operation, the scale depositing member 29 is heated to the shape recovery temperature or higher, so that the shape recovery force of the scale depositing member 29 overcomes the biasing force of the spring 32. For this reason, the scale depositing member 29 retains a memory shape (extended shape). On the other hand, the spring 32 is in a compressed state.

  FIG. 5 shows a state after the boiling operation is stopped. When the boiling operation is stopped, the application of current by the current application wire 34 is also stopped. Thereby, the temperature of the scale depositing member 29 falls. When the temperature of the scale depositing member 29 is lowered to a temperature lower than the shape recovery temperature, the scale depositing member 29 can withstand the urging force of the spring 32 and retain the memory shape (elongated shape) as shown in FIG. It can no longer be performed and is pushed from above by the spring 32 and deformed into a bent shape. On the other hand, the spring 32 is deformed from a compressed state to an extended state. Due to the mechanical (physical) action caused by these deformations, the scale S is peeled off from the surfaces of the scale depositing member 29 and the spring 32. The peeled scale S sinks downward and accumulates at the bottom of the scale accumulating portion 35 through the gap between the support members 37.

  According to the second embodiment described above, the same effect as in the first embodiment described above can be obtained. Further, in the present embodiment, the scale depositing member 29 can be heated by heating the scale depositing member 29 directly by energizing the scale depositing member 29 and causing the scale depositing member 29 itself to generate heat. For this reason, it is possible to reliably raise the temperature of the scale depositing member 29 with less energy.

Embodiment 3 FIG.
Next, the third embodiment of the present invention will be described with reference to FIG. 6 and FIG. 7. The difference from the above-described embodiment will be mainly described, and the same parts or corresponding parts will be denoted by the same reference numerals. The description is omitted.

  As shown in FIGS. 6 and 7, in the present embodiment, the housing 40 is detachably attached to the members constituting the flow path 36 by, for example, bolts or the like. A scale accumulation portion 35 is formed by the housing 40. The scale accumulating unit 35 is provided with a metal mesh 33. The housing 40 is provided with a heater 39 capable of heating the metal mesh 33.

  During the boiling operation, the metal mesh 33 is heated to a temperature higher than the temperature of the high-temperature water flowing out from the radiator 4 by the heater 39. For this reason, the hardness component contained in the high-temperature water is preferentially deposited on the high-temperature metal mesh 33 and adheres as the scale S.

  When a large amount of scale S adheres to the metal mesh 33 due to long-term use, the metal mesh 33 can be replaced with a new one by removing the housing 40 as shown in FIG. Further, when the scale depositing member 29 (not shown) installed in the flow path 36 is configured to be detachable, the scale depositing member 29 can be exchanged by removing the housing 40.

  As described above, in the present embodiment, the hardness component can be removed by the metal mesh 33 installed in the scale accumulation unit 35. Instead of the metal mesh 33, a plate-like member or a cylindrical member may be used.

28 Scale removing device 29 Scale depositing member 30 Heater 31 Weight 32 Spring 33 Metal mesh 34 Current application wire 35 Scale accumulating portion 36 Flow path 39 Heater 40 Housing

Claims (7)

A water heater provided with a heating source for heating water to form high-temperature water, and a scale removing device provided in the middle of a flow path of high-temperature water flowing out from the heating source,
The scale removing device includes:
A scale depositing member having a shape memory effect that recovers to a predetermined memory shape when the temperature is higher than a predetermined shape recovery temperature that is higher than the temperature of the high-temperature water flowing out of the heating source;
A temperature raising means for raising the temperature of the scale deposition member to a temperature equal to or higher than the shape recovery temperature;
When the scale depositing member is heated by the temperature raising means, the scale depositing member is deposited and adhered to the surface of the scale depositing member, the temperature raising by the temperature raising means is stopped, and the scale depositing member is other than the memory shape. A scale accumulating unit for storing scales separated from the scale depositing member by deforming into the shape of
A water heater characterized by comprising:   When the temperature raising by the temperature raising means is stopped and the temperature of the scale depositing member becomes lower than the shape recovery temperature, the scale depositing member is forced to deform into a shape other than the memory shape. The hot water heater according to claim 1, further comprising deformation means for adding   The hot water heater according to claim 2, wherein the deforming means generates the force according to a weight of a weight.   The hot water heater according to claim 2, wherein the deformation means generates the force by a biasing force of a spring.   5. The water heater according to claim 1, wherein the temperature raising unit includes an energizing unit configured to energize the scale depositing member itself by energizing the scale depositing member. All or part of the surface of the water flow path in the scale removing device is provided with a coating layer made of a material having a function of preventing adhesion of the scale,
The hot water heater according to any one of claims 1 to 5, wherein the coating layer is not provided on a surface of the scale depositing member.   The hot water heater according to any one of claims 1 to 6, wherein one or both of the scale accumulating unit and the scale depositing member are detachable.

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