JP2015194285A - Hot water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water supply device which has no drain piping, recovers sensible heat and latent heat from the combustion exhaust gas, and still can prevent leakage of a drain even after continuous usage for a long time.SOLUTION: An hot water supply device is a hot water supply device configured such that a second heat exchanger 26 recovers sensible heat from the combustion exhaust and a first heat exchanger 25 recovers latent heat from the combustion exhaust having exchanged heat with the second heat exchanger 26. The hot water supply device includes a by-pass pipe 6 which bypasses the first heat exchanger 25, a selector valve 61 which makes a switch to allow supplied water to flow through the first heat exchanger 25 or to flow through the by-pass pipe 6, and a control unit 7 which switches the selector valve 61 on the basis of the amount of a drain generating from the combustion exhaust having exchanged heat with the first heat exchanger 25.

Description

  The present invention relates to a hot water supply apparatus, and more particularly to a hot water supply apparatus that does not require a drain pipe.

  Patent Document 1 discloses a conventional hot water supply apparatus. The hot-water supply device described in Patent Document 1 (in Japanese Patent Application Laid-Open No. 2004-260688) includes a main heat exchanger that recovers sensible heat of combustion exhaust gas and a sub heat exchanger that recovers latent heat of combustion exhaust gas. The auxiliary heat exchanger is connected to the downstream side of the water supply pipe. The main heat exchanger is connected to the downstream side of the sub heat exchanger. A tapping pipe is connected to the downstream side of the main heat exchanger.

  The water supplied to the water supply pipe rises in temperature by exchanging heat with the combustion exhaust in the auxiliary heat exchanger, and further rises in temperature by exchanging heat with the combustion exhaust in the main heat exchanger. Water heated to a high temperature by the main heat exchanger is discharged through a discharge pipe.

  At this time, since the sensible heat is recovered by the main heat exchanger and the latent heat is recovered by the auxiliary heat exchanger, the combustion exhaust is condensed and changed into a drain.

  The water heater described in Patent Document 1 is provided with a drain evaporator below the auxiliary heat exchanger. The drain evaporator is configured to receive the drain generated by the auxiliary heat exchanger and be heated by the combustion exhaust. Thereby, the water heater described in Patent Document 1 has a structure in which a drain pipe for discharging the drain generated in the auxiliary heat exchanger to the outside of the apparatus is eliminated.

JP 2002-98413 A

  By the way, the water heater described in Patent Document 1 realizes a structure in which drain is evaporated by heating the drain evaporator, thereby eliminating drain piping. However, depending on the user, the water heater may be used continuously for a long time. In this case, the amount of drain generated from the auxiliary heat exchanger may exceed the amount of drain evaporation by the drain evaporator. is there. In this case, if the operation of the water heater is continued, the drain overflows from the drain evaporator, and as a result, there is a problem that the water leaks from the water heater.

  The present invention has been made in view of the above circumstances, and its object is to recover the sensible heat and latent heat of combustion exhaust and to continuously use it for a long time in a hot water supply apparatus that excludes a drain pipe. Even so, an object of the present invention is to provide a hot water supply device that can suppress drain leakage.

  The invention according to claim 1 of the present invention includes a supply pipe provided with a water supply port at an upstream end, a first heat exchanger connected to the supply pipe, and the first heat exchanger. A second heat exchanger connected to the downstream side of the first heat exchanger, a tapping pipe connected to the downstream side of the second heat exchanger and provided with a tapping outlet at the downstream end thereof, and the first heat exchanger A heat exchanger and a burner that exchanges heat with combustion exhaust, and recovers sensible heat of the combustion exhaust with the second heat exchanger, and with the first heat exchanger. A hot water supply apparatus configured to recover latent heat of combustion exhaust gas after heat exchange with the second heat exchanger, the hot water supply apparatus being provided between the supply pipe and the upstream side of the second heat exchanger. A bypass pipe that bypasses the first heat exchanger and water supplied to the water supply port, the first heat exchange A switching valve that switches between passing through the bypass pipe and bypassing the first heat exchanger through the bypass pipe, and switching the switching valve to a drain that is generated from the combustion exhaust heat-exchanged with the first heat exchanger. And a control device for switching based on the generation amount of the above.

  Thus, the invention according to claim 1 switches the switching valve based on the amount of drain generated. For this reason, when there is much drain generation amount, generation | occurrence | production of drain can be suppressed by bypassing a 1st heat exchanger about the supplied water. Moreover, when there is little generation | occurrence | production amount of drain, heat | fever can be effectively collect | recovered from combustion exhaust_gas | exhaustion by letting the supplied water pass a 1st heat exchanger. As a result, it is possible to suppress the leakage of drain even when the battery is continuously used for a long time while increasing the heat recovery rate as much as possible.

  According to a second aspect of the present invention, in the first aspect of the present invention, the drain receiver that receives drain generated from the combustion exhaust that has exchanged heat with the first heat exchanger, and the amount of drain accumulated in the drain receiver. A drain amount detector that detects the amount of drainage, and the control device bypasses the first heat exchanger through the bypass pipe when the drain amount detected by the drain amount detector reaches a predetermined amount. Switch the switching valve.

  Thus, in the invention according to claim 2, when the amount of drain accumulated in the drain receiver reaches a predetermined amount, the amount of drain generated is suppressed through the bypass pipe with the supplied water. For this reason, even if it is a case where it uses continuously for a long time, it can prevent that a drain overflows from a drain receptacle, and can suppress that a drain leaks.

  The invention according to claim 3 is the invention according to claim 2, further comprising a drain evaporator for evaporating the drain received by the drain receiver.

  For this reason, according to the invention which concerns on Claim 3, even if drain is received by a drain receptacle, the said drain can be evaporated and it can prevent that a drain overflows from a drain receptacle.

  According to a fourth aspect of the present invention, in the invention according to the third aspect, the drain evaporator includes a porous body that is provided in the drain receiver and sucks up the drain, and the porous body burns the burner. It is arranged in the exhaust passage.

  In the invention according to claim 4, since the porous body is disposed in the flow passage of the combustion exhaust, the drain sucked up by the porous body can be effectively evaporated. As a result, it is possible to prevent the drain from overflowing from the drain receiver.

  According to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, the drain evaporator includes a heater for vaporizing the drain accumulated in the drain receiver.

  For this reason, according to the invention which concerns on Claim 5, the evaporation of the drain collected by the drain receptacle can be accelerated | stimulated, As a result, it can prevent that a drain overflows from a drain receptacle.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, further comprising a temperature detector that detects the temperature of water in the first heat exchanger, and the control device includes: If the temperature value detected by the temperature detection unit exceeds a predetermined temperature in a state where the switching valve is switched so as to bypass the first heat exchanger through the bypass pipe, the first time The switching valve is switched so that the heat exchanger of 1 is passed.

  In the invention according to claim 6, when the water in the first heat exchanger continues to be heated and the water exceeds a predetermined temperature, the water in the supply pipe is circulated in the first heat exchanger. For this reason, it can prevent that the water in a 1st heat exchanger becomes an overheated state, and expands, and it can avoid that the inside of piping becomes an overpressure state.

  According to the hot water supply apparatus of the present invention, in a hot water supply apparatus that recovers sensible heat and latent heat of combustion exhaust and eliminates the drain piping, leakage of drain can be suppressed even when continuously used for a long time. .

It is sectional drawing of the water heater of this embodiment. It is a principal part expanded sectional view of the water heater of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a cross-sectional view of the hot water supply apparatus of the present embodiment. The hot water supply apparatus of the present embodiment incorporates two heat exchangers (first heat exchanger 25 and second heat exchanger 26), and not only sensible heat of combustion exhaust generated from the burner 24, It also recovers latent heat and efficiently generates hot water. On the other hand, when the latent heat is recovered, the combustion exhaust gas is condensed and changed into drainage. However, when the amount of drain generation increases, the hot water supply apparatus of this embodiment limits the recovery of latent heat and suppresses the amount of drain generation. To do. The hot water supply apparatus of this embodiment is a hot water heater that changes water into hot water and discharges the hot water to a faucet of a kitchen, a bathroom, or the like (hereinafter, the hot water supply apparatus of this embodiment is referred to as a hot water heater). As shown in FIG. 1, the water heater includes a housing 1, a combustion chamber 2, and a control device 7.

  The housing 1 is formed in a box shape. The housing | casing 1 forms the outline of a water heater. An air supply port 11 for taking outside air into the inside is provided at the lower portion of the housing 1. Further, an exhaust port 12 for exhausting the combustion exhaust generated by the burner 24 to the outside is provided in the upper part of the housing 1.

  The combustion chamber 2 is provided in the housing 1. The combustion chamber 2 generates hot water by heating water supplied from a water supply source. In the combustion chamber 2, an inflow port 21, an outflow port 22, and a flow passage 23 are provided. The inflow port 21 is provided in the lower part of the combustion chamber 2. The outlet 22 is provided in the upper part of the combustion chamber 2. The outflow port 22 leads to the exhaust port 12 of the housing 1. The flow passage 23 communicates the inflow port 21 and the outflow port 22. The combustion chamber 2 includes a burner 24, a first heat exchanger 25, a second heat exchanger 26, and a fan 27.

  The fan 27 is provided below the inflow port 21. The fan 27 supplies outside air (combustion primary air) to the burner 24. When the fan 27 is driven, air is taken into the housing 1 from the air supply port 11, and the taken-in air flows into the combustion chamber 2 through the inflow port 21. The fan 27 is electrically connected to the control device 7 and is driven and controlled by the control device 7.

  The burner 24 is accommodated in the combustion chamber 2. The burner 24 is supplied with a premixed gas and burns to generate combustion exhaust. The combustion exhaust gas flows along the flow passage 23 and is discharged through the outlet port 22. The premixed gas is generated by mixing the fuel gas and the primary air from the fan 27 before the burner 24 burns.

  A first heat exchanger 25 and a second heat exchanger 26 are arranged above the burner 24. The first heat exchanger 25 and the second heat exchanger 26 are provided in contact with the combustion exhaust generated from the burner 24.

  The first heat exchanger 25 is configured, for example, by providing heat dissipation fins on a meandering stainless steel tube. A supply pipe 28 is connected to the inlet of the first heat exchanger 25. A water supply port 32 is provided at the upstream end of the supply pipe 28. When water is supplied from the water supply port 32, the water flows into the first heat exchanger 25. A second heat exchanger 26 is connected to the downstream side of the first heat exchanger 25.

  The second heat exchanger 26 is provided below the first heat exchanger 25 and accommodated in the combustion chamber 2. The second heat exchanger 26 is connected to the first heat exchanger 25 through the connection pipe 30. The connection pipe 30 has an upstream end connected to the outlet of the first heat exchanger 25 and a downstream end connected to the inlet of the second heat exchanger 26.

  The second heat exchanger 26 is configured, for example, by providing heat dissipation fins on a meandering copper tube. A tapping pipe 31 is connected to the downstream end of the second heat exchanger 26. An open / close valve 29 is provided in the middle of the hot water discharge pipe 31, and the flow state of the water supplied to the water heater (that is, water discharge and water stoppage) is switched by opening / closing driving of the open / close valve 29. A hot water outlet 33 is provided at the downstream end of the hot water pipe 31.

  The hot water outlet 33 and the water supply port 32 of the supply pipe 28 are provided exposed from the lower end of the housing 1. A water supply pipe that communicates with a water supply source (for example, a water pipe) is connected to the water supply port 32. The hot water outlet 33 is connected to a hot water outlet such as a mixed water tap, for example.

  When the burner 24 burns with water supplied from the water supply port 32, the combustion exhaust generated by the burner 24 comes into contact with the second heat exchanger 26 and the combustion exhaust that has passed through the second heat exchanger 26. Comes into contact with the first heat exchanger 25. Then, the water flowing through the supply pipe 28 flows into the first heat exchanger 25, heat exchange with the combustion exhaust gas, and the temperature rises. Thereafter, the water whose temperature has risen flows into the second heat exchanger 26, exchanges heat with the combustion exhaust gas, and further rises in temperature. Then, the water that has passed through the second heat exchanger 26 is discharged from the hot water outlet 33.

  At this time, the sensible heat of the combustion exhaust is recovered by the second heat exchanger 26, and thereafter, the latent heat (latently, latent heat and sensible heat) is recovered by the first heat exchanger 25. As a result, the water heater can effectively heat the water supplied to the water supply port 32.

  When the latent heat is recovered by the first heat exchanger 25, the combustion exhaust is condensed and changed into a drain. Therefore, drain adheres to the first heat exchanger 25. This drain is received by a drain receiver 4 provided in the combustion chamber 2 as shown in FIG.

  The drain receiver 4 includes a water guiding portion 41 and a container portion 42. The water guide section 41 is disposed below the first heat exchanger 25. The water guide section 41 is inclined so as to be positioned downward toward the container section 42. The drain that has fallen on the water guide part 41 flows down according to the inclination and is collected in the container part 42.

  The container part 42 has a bottomed box shape opened upward. Drain generated by the first heat exchanger 25 is collected in the container part 42. The water heater is provided with a drain evaporator 5 that evaporates the drain received in the container part 42.

  The drain evaporator 5 evaporates the drain received by the drain receiver 4. The drain evaporator 5 includes a porous body 51. The upper end of the porous body 51 is in contact with or close to the upper end of the combustion chamber 2. Thereby, the porous body 51 is disposed in the flow passage 23. The porous body 51 is made of, for example, ceramic in which fine holes are formed over the entire surface. The porous body 51 sucks up the drain collected in the container part 42 by capillary action.

  Since the porous body 51 that has sucked up the drain of the container portion 42 is disposed in the flow passage 23, it is exposed to the combustion exhaust gas that has passed through the first heat exchanger 25. For this reason, the drain sucked up by the porous body 51 is vaporized by the combustion exhaust. Thereby, according to the drain evaporator 5 of this embodiment, the drain collected by the container part 42 can be evaporated.

  In addition to being able to effectively evaporate the drain, the water heater of the present embodiment has a function of suppressing the generation of drain, thereby preventing the drain from overflowing. The water heater of this embodiment switches whether the water flowing through the supply pipe 28 does not pass through the first heat exchanger 25 or passes through the first heat exchanger 25 based on the amount of drain. Can do.

  As shown in FIG. 1, the water heater has a bypass pipe 6 spanned between a connection pipe 30 and a supply pipe 28. The bypass pipe 6 is provided between the supply pipe 28 and the connection pipe 30. In other words, the bypass pipe 6 is provided between the supply pipe 28 and the upstream side of the second heat exchanger 26. When water passing through the supply pipe 28 flows through the bypass pipe 6, it bypasses the first heat exchanger 25 and flows into the second heat exchanger 26.

  The bypass pipe 6 is provided with a switching valve 61 for switching the flow path. The switching valve 61 switches the water supplied to the water supply port 32 to either the first heat exchanger 25 or to bypass the first heat exchanger 25 through the bypass pipe 6. The switching valve 61 of this embodiment is configured by a three-way valve. In addition, as the switching valve 61, you may switch a flow path using a some solenoid valve, for example. The switching valve 61 is electrically connected to the control device 7, and flow path switching control is performed by the control device 7.

  Further, the drain receiver 4 is provided with a drain amount detection unit 8 as shown in FIG. The drain amount detection unit 8 is fixed to the side wall of the container unit 42. The drain amount detection unit 8 is provided away from the bottom surface of the container unit 42 by a predetermined dimension. Thereby, the drain amount detection part 8 can detect it, when the liquid level of the drain collected by the container part 42 reaches a fixed water level. That is, the drain amount detection unit 8 can detect the amount of drain accumulated in the drain receiver 4. The drain amount detection unit 8 is electrically connected to the control device 7.

  The control device 7 switches the switching valve 61 when the detection signal is input from the drain amount detection unit 8. When the detection signal is input from the drain amount detection unit 8, the control device 7 switches the switching valve 61 so that water passing through the supply pipe 28 bypasses the first heat exchanger 25 through the bypass pipe 6. That is, when the drain amount detected by the drain amount detector 8 reaches a predetermined amount, the control device 7 switches the switching valve 61 so as to bypass the first heat exchanger 25 through the bypass pipe 6. Thereby, it is possible to prevent water having a low temperature from passing through the first heat exchanger 25. As a result, the recovery of latent heat can be suppressed and the generation of drain can be suppressed.

  By the way, when the operation is continued in a state where the low temperature water bypasses the first heat exchanger 25, the combustion exhaust continues to heat the first heat exchanger 25, and the water in the first heat exchanger 25 remains. Since it continues to be heated, it may overheat. In this case, the water in the 1st heat exchanger 25 will expand, and the pressure in piping will rise too much.

  In order to prevent this, the water heater of the present embodiment includes a pressurization preventing means. The pressurization preventing means includes a temperature detection unit (not shown) that detects the temperature of water in the first heat exchanger 25, the switching valve 61, and the control device 7.

  The temperature detection unit is configured by, for example, a temperature sensor inserted into the first heat exchanger 25. When the temperature detection unit detects the temperature of the water in the first heat exchanger 25, it outputs the temperature value to the control device 7.

  When the temperature value is input from the temperature detection unit, the control device 7 determines whether the temperature value is equal to or higher than a predetermined temperature. When determining that the temperature value is equal to or higher than the predetermined temperature, the control device 7 causes the switching valve 61 to pass through the first heat exchanger 25 for a certain time (for example, about 5 seconds) and the water passing through the supply pipe 28 passes through the first heat exchanger 25. The switching valve 61 is switched.

  Then, the water in the first heat exchanger 25 in an overheated state starts to flow and is sent to the second heat exchanger 26, whereby the pressure in the pipe is released.

  The pressurization preventing means is not limited to the above configuration, and may be configured by, for example, a pressure relief valve that is connected to the first heat exchanger 25 in communication.

  The water heater having such a configuration operates as follows.

  When the water supplied to the water supply port 32 flows through the first heat exchanger 25 and the second heat exchanger 26, the water in the heat exchangers 25 and 26 and the combustion exhaust generated from the burner 24 are used. Exchange heat. The water that has received heat from the combustion exhaust gas rises in temperature and is discharged from the hot water outlet 33.

  At this time, drain is generated in the first heat exchanger 25. The drain falls to the water guide part 41 and is collected in the container part 42. Most of the drain collected in the container 42 is sucked up by the porous body 51, but the drain that is not sucked up by the porous body 51 is stored in the container 42.

  The drain sucked up by the porous body 51 is evaporated by the combustion exhaust. The porous body 51 further sucks up the drain from the container portion 42 by the amount evaporated. When the evaporation amount (that is, the suction amount) of the drain sucked up by the porous body 51 is larger than the drain generation amount, the drain does not collect in the container part 42. On the other hand, when the evaporation amount of the drain sucked up by the porous body 51 is smaller than the generation amount of the drain, the drain amount of the container part 42 increases as the operation continues.

  In this case, when the liquid level of the drain in the container portion 42 rises and reaches a certain liquid level, the drain amount detection unit 8 detects the drain amount. Then, the control device 7 drives and controls the switching valve 61, and the water flowing through the supply pipe 28 flows so as to bypass the first heat exchanger 25 through the bypass pipe 6.

  Thereby, since low temperature water does not flow into the 1st heat exchanger 25, recovery of the latent heat of combustion exhaust by the 1st heat exchanger 25 is controlled. As a result, the generation of drain is suppressed, and the evaporation amount of drain sucked up by the porous body 51 becomes larger than the generation amount of drain.

  When the burner 24 continues to burn in this state, the drain liquid level in the container part 42 is lowered, and the drain liquid level is not detected by the drain amount detection unit 8. Then, the control device 7 switches the switching valve 61 so that the water flowing through the supply pipe 28 passes through the first heat exchanger 25. Thereby, the water heater is again in a state with a high heat recovery rate.

  As described above, the water heater (hot water supply apparatus) of the present embodiment includes the supply pipe 28, the first heat exchanger 25, the second heat exchanger 26, the tap water pipe 31, and the burner 24. It has. The supply pipe 28 is provided with a water supply port 32 at the upstream end. The first heat exchanger 25 is connected to the supply pipe 28. The second heat exchanger 26 is connected to the downstream side of the first heat exchanger 25. The tapping pipe 31 is connected to the downstream side of the second heat exchanger 26, and a tapping port 33 is provided at the downstream end thereof. The burner 24 performs heat exchange between the first heat exchanger 25 and the second heat exchanger 26 and the combustion exhaust gas. In this water heater, the sensible heat of the combustion exhaust is recovered by the second heat exchanger 26, and the latent heat of the combustion exhaust after heat exchange with the second heat exchanger 26 is recovered by the first heat exchanger 25. It is configured as follows. The water heater includes a bypass pipe 6, a switching valve 61, and a control device 7 that controls the switching valve 61. The bypass pipe 6 is provided between the supply pipe 28 and the upstream side of the second heat exchanger 26. The switching valve 61 switches whether the water supplied to the water supply port 32 passes through the first heat exchanger 25 or bypasses the first heat exchanger 25 through the bypass pipe 6. The control device 7 switches the switching valve 61 based on the amount of drain generated from the combustion exhaust gas heat-exchanged with the first heat exchanger 25.

  The water heater of this embodiment switches the switching valve 61 based on the amount of drain generation. For this reason, when there is much drain generation amount, generation | occurrence | production of drain can be suppressed by bypassing the 1st heat exchanger 25 about the supplied water. Further, when the amount of generated drain is small, heat can be effectively recovered from the combustion exhaust gas by passing the supplied water through the first heat exchanger 25. As a result, drainage can be prevented from leaking even when continuously used for a long time while increasing the heat recovery rate as much as possible.

  Further, the water heater of this embodiment includes a drain receiver 4 that receives drain generated from the combustion exhaust that has exchanged heat with the first heat exchanger 25, and a drain amount detection that detects the amount of drain accumulated in the drain receiver 4. Part 8. When the drain amount detected by the drain amount detection unit 8 reaches a predetermined amount, the control device 7 switches the switching valve 61 so as to bypass the first heat exchanger 25 through the bypass pipe 6.

  In the water heater of this embodiment, when the amount of drain accumulated in the drain receiver 4 reaches a predetermined amount, the amount of drain generated is suppressed. For this reason, according to the hot water heater of this embodiment, it is possible to prevent drain leakage even when it is continuously used for a long time.

  The water heater of the present embodiment further includes a drain evaporator 5 that evaporates the drain received by the drain receiver 4.

  For this reason, according to the water heater of this embodiment, even if drain is received by the drain receiver 4, the drain can be evaporated and the drain can be prevented from overflowing.

  In addition, the drain evaporator 5 of the present embodiment includes a porous body 51 that is provided on the drain receiver 4 and sucks up the drain. The porous body 51 is disposed in the flow passage 23 of the combustion exhaust of the burner 24.

  Thus, when the porous body 51 is disposed in the flow passage 23 of the combustion exhaust, the drain sucked up by the porous body 51 can be effectively evaporated. As a result, the drain accumulated in the drain receiver 4 can be effectively evaporated.

  In addition, the water heater of this embodiment further includes a temperature detection unit that detects the temperature of the water in the first heat exchanger 25. When the temperature value detected by the temperature detection unit exceeds a predetermined temperature in a state in which the switching valve 61 is switched so as to bypass the first heat exchanger 25 through the bypass pipe 6, the control device 7 performs a predetermined time. The switching valve 61 is switched so that the first heat exchanger 25 is passed.

  The water heater of this embodiment distribute | circulates the water in the supply pipe | tube 28 in the 1st heat exchanger 25, if the water in the 1st heat exchanger 25 continues heating. For this reason, it can prevent that the water in the 1st heat exchanger 25 becomes an overheated state, and expands, and it can avoid that the inside of piping becomes an overpressure state.

  In addition, the drain evaporation device 5 of the present embodiment promotes the evaporation of the drained water collected in the drain receiver 4 by providing the drain receiver 4 with the porous body 51. In addition, the drain receiver 4 You may heat with a heater. A heater is attached so that the container part 42 may be heated from the back side of the bottom face of the container part 42 of the drain receptacle 4, for example. Thereby, vaporization of the drain accumulated in the drain receiver 4 is further promoted.

  This heater may be additionally provided on the porous body 51 or may be provided in place of the porous body 51. That is, the drain evaporator 5 may include the porous body 51 and the heater, or only one of them.

  The hot water supply apparatus of the present embodiment is a so-called hot water heater. However, the “hot water supply apparatus” of the present invention includes the above-described hot water heater having a hot water supply function, floor heating using a hot water as a heat source, and a bathroom heating dryer. It may be a hot water heating heat source machine that also has a function of circulating hot water, or a bath water heater that also has a function of circulating hot water in a bathtub.

  Moreover, although the hot water heater of this embodiment switched supply of hot water and water stop by driving the on-off valve 29, the presence or absence of water in the water heater is detected without providing the on-off valve 29. A water flow sensor may be provided in the water heater, and the control device may control the combustion of the burner based on the detection signal of the water flow sensor. As a result, when the user opens and closes the hot water supply destination, the water flow sensor detects the flow of water in the water heater, and the combustion of the burner is controlled accordingly.

DESCRIPTION OF SYMBOLS 1 Housing | casing 11 Supply port 12 Exhaust port 2 Combustion chamber 21 Inlet 22 Outlet 23 Outflow path 24 Burner 25 1st heat exchanger 26 2nd heat exchanger 27 Fan 28 Supply pipe 29 On-off valve 30 Connection pipe 31 Hot water pipe 32 Supply port 33 Hot water outlet 4 Drain receiver 41 Water transfer part 42 Container part 5 Drain evaporation device 51 Porous body 6 Bypass pipe 61 Switching valve 7 Control device 8 Drain amount detection part

Claims (6)

A supply pipe provided with a water supply port at the upstream end; and
A first heat exchanger connected to the supply pipe;
A second heat exchanger connected downstream of the first heat exchanger;
A tapping pipe connected to the downstream side of the second heat exchanger, and having a tapping outlet at the downstream end thereof,
The first heat exchanger and the second heat exchanger, and a burner that performs heat exchange by combustion exhaust,
The sensible heat of the combustion exhaust is recovered by the second heat exchanger, and the latent heat of the combustion exhaust after heat exchange with the second heat exchanger is recovered by the first heat exchanger. A water heater,
A bypass pipe provided between the supply pipe and the upstream side of the second heat exchanger to bypass the first heat exchanger;
For the water supplied to the water supply port, a switching valve that switches between passing the first heat exchanger or bypassing the first heat exchanger through the bypass pipe;
A hot water supply apparatus comprising: a control device that switches the switching valve based on the amount of drain generated from the combustion exhaust that has exchanged heat with the first heat exchanger. A drain receiver for receiving drain generated from the combustion exhaust heat-exchanged with the first heat exchanger;
A drain amount detector for detecting the amount of drain accumulated in the drain receiver;
The control device switches the switching valve so as to bypass the first heat exchanger through the bypass pipe when the drain amount detected by the drain amount detection unit reaches a certain amount. Item 2. A hot water supply apparatus according to item 1. The hot water supply apparatus according to claim 2, further comprising a drain evaporation device that evaporates the drain received by the drain receiver. The said drain evaporation apparatus is provided with the porous body which is provided in the said drain receptacle, and sucks up a drain, The said porous body is arrange | positioned in the flow path of the combustion exhaust gas of the said burner. Water heater. The hot water supply device according to claim 3 or 4, wherein the drain evaporator includes a heater for vaporizing the drain accumulated in the drain receiver. A temperature detection unit for detecting the temperature of water in the first heat exchanger;
When the temperature value detected by the temperature detection unit exceeds a predetermined temperature in a state where the switching valve is switched so that water is bypassed to the first heat exchanger through the bypass pipe, The hot water supply device according to any one of claims 1 to 5, wherein the switching valve is switched so as to pass the first heat exchanger for a period of time.

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