JP2009109189A - Storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage type water heater suppressing deterioration in energy efficiency while operating a relief valve in the same way as in the conventional art. <P>SOLUTION: In the storage type water heater for heating low temperature water in a hot water storage tank 2 and storing it as high temperature hot water, a bypass passage 41 is composed to connect an upper part to a lower part of the hot water storage tank 2, and a pressure releasing means 43 is connected to the bypass passage 41. In the bypass passage 41, a heat exchanging part 3 and a pump 12 are interposed for heating hot water inside a bath tub 4, and a reverse flow prevention means 47 is interposed in a higher position than the heat exchanging part 3 above the hot water storage tank 2. The reverse flow prevention means 47 is not opened by a differential pressure caused by convection from an upper part of the hot water storage tank 2 to the bottom part of the hot water storage tank 2 through the bypass passage 41, and is opened by differential pressure generated by drive of the pump 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hot water storage type water heater.

  FIG. 4 is a block diagram showing an embodiment of the hot water storage type hot water supply apparatus of the present invention, and the prior art will be described with reference to this figure. As shown in the figure, the hot water storage type hot water heater includes a heat pump unit 1 as an example of a heating unit, a hot water storage tank 2 for storing hot water heated by the heat pump unit 1, and hot water supplied from the hot water storage tank 2. A reheating heat exchanging unit 3 for exchanging heat with hot water in the bathtub 4 and a control device 10 are provided.

  One end of the pipe 31 is connected to the input side of the heat pump unit 1, and the other end of the pipe 31 is connected to the lower side of the hot water storage tank 2. On the other hand, one end of the pipe 32 is connected to the output side of the heat pump unit 1, and the other end of the pipe 32 is connected to the upper side of the hot water storage tank 2. A pump 11 is provided in the pipe 31, and hot water (or water) in the hot water storage tank 2 is circulated through the pipe 31, the heat pump unit 1, and the pipe 32 by the pump 11.

  A water supply pipe 33 is connected to the lower side of the hot water storage tank 2, and one end of the water supply pipe 34 is connected to the water supply pipe 33. The other end of the water supply pipe 34 is connected to one input of the mixing valve 25, and the other input of the mixing valve 25 is connected to the upper side of the hot water storage tank 2 via the hot water supply pipe 35.

  The upper side of the hot water storage tank 2 is connected to the primary side and the upper side of the heat exchange unit 3 via a pipe 36, and the lower side of the hot water storage tank 2 and the primary side and the lower side of the heat exchange unit 3 are connected to a pipe 37. Connected through. The pump 12 is provided in the pipe 37, and the hot water in the hot water storage tank 2 is circulated by the pump 12 through the pipe 36, the heat exchange unit 3, and the pipe 37.

  Further, the secondary side and the lower side of the heat exchange unit 3 and the circulation port 20 of the bathtub 4 are connected via a pipe 38, and the secondary side and the upper side of the heat exchange unit 3 and the circulation port 20 of the bathtub 4 are connected. Connection is made via a pipe 39. A pump 13 is provided in the pipe 38, and hot water in the bathtub 4 is circulated by the pump 13 through the pipe 38, the heat exchange unit 3, and the pipe 39. As hot water in the bathtub 4 circulates through the secondary side of the heat exchange unit 3, the hot water in the bathtub 4 is heated by heat exchange with the hot water supplied from the hot water storage tank 2.

  The pipe 38 is provided with a water level sensor 21 as an example of a hot water amount sensor for detecting the water level in the bathtub 4 and a temperature sensor 22 for detecting the hot water temperature in the bathtub 4.

  One end of the hot water supply pipe 40 is connected to the outlet of the mixing valve 25, and the other end of the hot water supply pipe 40 is connected to the pipe 39. The hot water supply pipe 40 is provided with a flow sensor 23 for detecting the amount of hot water and a temperature sensor 24 for detecting the temperature of the hot water. The water supply pipes 33 and 34, the mixing valve 25, and the hot water supply pipes 35 and 40 constitute a hot water supply unit. The hot water in the hot water storage tank 2 is pushed up by the water supplied from the water supply pipe 33, and the high-temperature water in the upper part of the hot water storage tank 2 is pushed out from the hot water supply pipe 35 to supply hot water.

  Although not shown, the heat pump unit 1 includes a refrigerant circuit in which a compressor, a condenser (water heater), an expansion unit, and an evaporator are connected in an annular shape, and the pump 11 uses heat generated by the condenser. Heat the circulated hot water. In this embodiment, the temperature of the high-temperature water supplied to the upper part in the hot water storage tank 2 by the heat pump unit 1 is set to 80 ° C.

  In such a water heater, a relief valve is provided at the top of the hot water storage tank 2 to prevent the hot water from expanding during the boiling operation and the internal pressure of the hot water storage tank 2 from increasing. In addition, an air vent valve for removing stored air is attached near the top of the hot water storage tank 2 (see, for example, Patent Documents 1 and 2).

JP 2001-267991 A Japanese Patent Laid-Open No. 08-219555

  By the way, when a relief valve is attached to the top of the hot water storage tank 2 as in the hot water heater, the hot water stored in the upper part of the hot water storage tank 2 is ejected to the outside by the operation of the relief valve. Become. And since hot water is jetted out and lost in this way, in the hot water storage tank 2, wasteful energy consumption is made, resulting in a decrease in energy efficiency during boiling.

  The present invention has been made to solve the above-described conventional drawbacks, and its object is to provide a hot water storage type hot water heater capable of suppressing a decrease in energy efficiency while operating a relief valve as in the conventional case. Is to provide.

Accordingly, the hot water storage type water heater of claim 1 is a hot water storage type hot water heater that heats low temperature water in the hot water storage tank 2 and stores it as high temperature hot water, and constitutes a bypass passage 41 that connects the upper and lower parts of the hot water storage tank 2. In addition, the pressure release means 43 is connected to the bypass passage 41, and the bypass passage 41 is provided with a heat exchange unit 3 and a pump 12 for heating hot water in the bathtub 4, and in the bypass passage 41, Further, a backflow prevention means 47 is provided on the upper side of the hot water storage tank 2 with respect to the heat exchange unit 3, and the backflow prevention means 47 passes from the upper part of the hot water storage tank 2 through the bypass path 41 to the bottom of the hot water storage tank 2. It is characterized in that the valve is not opened by the differential pressure caused by the convection leading to the valve, but is opened by the differential pressure generated by driving the pump 12 .

  2. The hot water storage type hot water supply apparatus according to claim 1, wherein when the pressure in the hot water storage tank 2 rises and the pressure release means 43 is activated during the boiling operation of the hot water in the hot water storage tank 2, the low temperature water in the bypass passage 41 is diffused to the outside. Is done. In this way, high-temperature hot water is not diffused as in the prior art, but low-temperature water is diffused, so that the dissipated heat can be suppressed and heat storage loss can be reduced.

Further, in the hot water storage type hot water heater, since the bypass passage 41 is also used as a configuration essential to the hot water storage type hot water heater, the equipment cost can be greatly reduced as compared with the case where the bypass passage 41 is completely configured. Is possible. Further, since the backflow prevention means 47 required at that time prevents natural convection through the high-temperature hot water bypass passage 41 in the hot water storage tank 2, it is possible to suppress the occurrence of energy loss in this respect as well. It is.

It is a circuit diagram which expands and shows the principal part in 1st Embodiment of the hot water storage type water heater of this invention. It is a circuit diagram which expands and shows the principal part in 2nd Embodiment of the hot water storage type water heater of this invention. It is a circuit diagram which expands and shows the principal part in 3rd Embodiment of the hot water storage type water heater of this invention. It is a whole circuit diagram in each said embodiment of the hot water storage type water heater of this invention.

  Next, specific embodiments of the hot water storage type water heater of the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a water circuit diagram showing an enlarged main part A in FIG. As shown in the figure, a bypass passage 41 connecting the upper and lower portions of the hot water storage tank 2 is configured, and a valve attachment port 42 is provided in the bypass passage 41 to connect a relief valve 43. Here, although the relief valve 43 constitutes the pressure release means, it should be understood that it constitutes a part of the valve attachment port 42. In this case, the bypass passage 41 is constituted by the pipes 36 and 37 connected to the heat exchange unit 3 and the internal passage 3 a of the heat exchange unit 3. More specifically, the bypass passage 41 includes an upper bypass passage 41a connected to the upper portion (top portion) of the hot water storage tank 2, a narrow portion 44, an air reservoir portion 45, a pipe 36, an internal passage 3a of the heat exchange portion 3, and a hot water storage tank. 2 and a pipe 37 connected to the lower part (bottom part). That is, the bypass passage 41 is provided with a high place located at a position higher than the top of the hot water storage tank 2, and this high place is used as an air reservoir 45, and a valve is provided in the vicinity thereof (slightly below the air reservoir). An attachment port 42 is provided. In this case, the valve attachment port 42 is arranged at a position higher than the top of the hot water storage tank 2. Further, between the air reservoir 45 and the upper bypass passage 41a, a narrow portion 44 having a flow passage area smaller than the flow passage area of other portions in the bypass passage 41 is formed.

  Here, the air reservoir 45 will be further described. In the air reservoir 45, when the initial tank is supplied with water, the inside of the pipe is close to the atmospheric pressure, but the air in the pipe exists in the X portion due to the flowing water dynamic pressure. Move to Y when water supply is complete. At this time, since the pressure is increased up to the pressure of the relief valve 43 at this time, the air volume is compressed, but it is necessary to retain air in the Y portion in this state. Therefore, in consideration of the ratio between the atmospheric pressure and the set pressure of the relief valve 43, it is preferable to set the volume of the X part to be not less than three times the volume of the Y part.

  The bypass passage 41 is provided with a first communication passage 46 that bypasses the narrow portion 44 and the air reservoir 45 and communicates the upper bypass passage 41a and the bypass passage 41 (passage 36). 46 is provided with a first check valve (first backflow prevention means) 47. The first check valve 47 does not open at the pressure difference due to convection from the upper part of the hot water storage tank 2 to the bottom of the hot water storage tank 2 through the upper bypass passage 41a and the bypass passage 41, and the pump 12 The valve is configured to open with a differential pressure generated by the driving. Here, the differential pressure due to convection is a pressure difference generated by the density difference between the hot water storage tank 2 and the bypass passage 41, and the water density difference is a maximum of 3.6% in the range of 0 to 90 ° C. Therefore, when the height of the hot water storage tank 2 is about 2 m, the water head pressure (0.72 kPa) is about 72 mm.

  Also, a second communication passage 48 that bypasses the front and rear of the first check valve 47 is provided, and a second communication passage 48 that allows air flow from the pressure release means 43 to the upper portion of the hot water storage tank 2 is provided. A check valve (second backflow prevention means) 49 is provided.

  In the hot water storage type water heater of the above embodiment, when the pressure in the hot water storage tank 2 rises and the relief valve 43 is activated during the boiling operation of the hot water in the hot water storage tank 2, the low temperature water in the bypass passage 41 is diffused to the outside. The In this way, high-temperature hot water is not diffused as in the prior art, but low-temperature water is diffused, so that the dissipated heat can be suppressed and heat storage loss can be reduced. As a result, specifically, the device efficiency can be improved by about 3% (specific gravity decrease from 15 ° C. to 85 ° C.). Further, since the staying air is also diffused to the outside together with the low-temperature water, it is not necessary to install an air venting device as in the prior art, and the equipment cost can be reduced. Moreover, since the narrow portion 44 is provided, it is possible to reliably suppress the diffusion of the high-temperature hot water, so that the device efficiency can be improved more reliably.

  Further, the bypass passage 41 is constituted by the pipes 36 and 37 connected to the heat exchanging section 3 and the internal passage 3a of the heat exchanging section 3, and the bypass passage 41 is also used as an indispensable structure for the hot water storage type hot water heater. Therefore, it is possible to significantly reduce the equipment cost as compared with the case where the bypass path 41 is configured separately. Further, the first check valve 47 required at that time prevents natural convection through the high-temperature hot water bypass passage 41 in the hot water storage tank 2. Therefore, it is possible to suppress the occurrence of energy loss also in this respect. Further, since the air from the pressure release means 43 is allowed to flow to the side opposite to the first check valve 47, that is, the hot water tank 2 side, a negative pressure is generated in the hot water tank 2 ( For example, in the case of downstairs hot water), intake performance can be improved and damage to the tank 2 can be prevented.

  FIG. 2 shows a second embodiment. This omits the installation of the second communication passage 48 and the second check valve 49 in the first embodiment. In the second embodiment, except for matters related to the negative pressure, substantially the same operational effects as those of the first embodiment can be obtained.

FIG. 3 shows a third embodiment. In the second embodiment, the narrow portion 44 and the air reservoir 45 are omitted, and the first communication passage 46 forms a part of the bypass passage 41. In this embodiment, although the air venting device 50 is necessary, except for the operational effects resulting from the narrowed portion 44 and the air reservoir 45, substantially the same operational effects as the second embodiment can be obtained. In the second to third embodiments, each part having the same function as that of the first embodiment is denoted by the same reference numeral as that of the first embodiment, and the description thereof is omitted.

  2 .. Hot water storage tank, 3 .. Heat exchange section, 4 .. Bathtub, 12 .. Pump, 41 .. Bypass passage, 42 .. Valve mounting port, 43 .. Relief valve (pressure release means), 44. Narrow part, 45 ... Air reservoir, 46 ... First communication passage, 47 ... First check valve (first backflow prevention means), 48 ... Second communication passage, 49 ... Second check valve (Second backflow prevention means)

Claims (1)

In a hot water storage type hot water heater that heats low temperature water in a hot water storage tank (2) and stores it as high temperature hot water, a bypass path (41) that connects the upper and lower parts of the hot water storage tank (2) is formed, and this bypass path (41 ) Is connected to the pressure release means (43), and further, the bypass (41) is provided with a heat exchange section (3) and a pump (12) for heating the hot water in the bathtub (4). At the same time, in the bypass passage (41), the backflow prevention means (47) is provided at a position on the upper side of the hot water storage tank (2) with respect to the heat exchange section (3), and the backflow prevention means (47) The differential pressure caused by driving the pump (12) does not open with the differential pressure caused by convection from the upper part of the hot water storage tank (2) through the bypass passage (41) to the bottom of the hot water storage tank (2). storage-type feed, characterized in that configured to open Machine.