Hot water supply device

Abstract

To provide a water heater which has few construction failure, excellent workability, and an instantaneous hot water function.SOLUTION: A casing 10 of a water heater 1 includes: an instantaneous hot water liquid-liquid heat exchanger 313: hot water supply side heating means 30; heating side heating means 40; a water supply passage 90 and a hot water supply passage 100 connected to the hot water supply side heating means 30; an instantaneous hot water circulation passage 300 which is connected to the hot water supply passage 100, and in which hot water / water circulates while the hot water supply is stopped; an instantaneous hot water circulation pump 311 for circulating hot water / water in the instantaneous hot water circulation passage 300; a heating branch circulation passage 270 which is connected to the heating side heating means 40, and in which a heating medium circulates; a heating circulation pump 211 which allows the heating medium to circulate in the heating branch circulation passage 270; the instantaneous hot water liquid-liquid heat exchanger 313 for heating the hot water / water circulating in the instantaneous hot water circulation passage 300 by the heating medium circulating in the heating branch circulation passage 270; and a hot water supply passage check valve 107. In the vicinity of a bottom plate 11 of the casing 10, an instantaneous hot water return passage check valve 320 and instantaneous hot water drain plugs 321, 322 are provided.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a water supply device having an instant hot water function.

Background Art

[0002] Conventionally, there has been proposed a hot water supply system having an instant hot water function, which includes a hot water heater that heats hot and cold water to a predetermined temperature, a circulation device that circulates the hot and cold water in a circulation path constructed between a downstream portion of a hot water supply pipe and the hot water heater, an expansion tank that absorbs volume expansion of the hot and cold water in the circulation path, a main water supply pipe that introduces water from a water supply pipe to the hot water heater, a main hot water supply pipe that leads the hot and cold water from the hot water heater to the hot water supply pipe through a hot water outlet pipe connected to a heat exchanger, and a main return pipe that guides the hot and cold water from the downstream portion of the hot water supply pipe to the circulation device (for example, Patent Document 1).

[0003] In the hot water supply system described in Patent Document 1 above, since a circulation device and the like are retrofitted to the hot water heater, a circulation device composed of unit members in which element members such as a water passage pipe, a circulation pump, and a pressure relief valve are incorporated in a housing is disposed outside the hot water heater and is connected to the hot water heater and the expansion tank by piping.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the hot water supply device as described above, it is necessary to prevent backflow of the hot and cold water circulating in the circulation path into the water supply pipe. Further, in a hot water supply device in which a hot water filling path for filling a bathtub is connected to the hot water outlet pipe, it is necessary to prevent backflow of the hot and cold water circulating in the circulation path into the hot water filling path. For this reason, a check valve is provided in the water passage pipe on the downstream side of the circulation pump in the circulation device of Patent Document 1.

[0006] However, in a hot water supply system such as that of Patent Document 1, a plurality of devices must be connected to the hot water heater at the installation site, and construction defects such as incorrect connection directions and poor connections are likely to occur. Further, when using a non-self-priming circulation pump, it is necessary to fill the circulation path with so-called priming water in advance during construction or the like. Therefore, it is necessary to provide a drain cock in the circulation path and open the drain cock during the trial operation to bleed air from the circulation path. However, the circulation path may be arranged for several tens of meters. Therefore, if the drain cock is installed in the circulation path far from the hot water supply device, the operator must travel back and forth between the hot water supply device and the drain cock, resulting in poor workability.

[0007] The present invention solves the above problems, and an object of the present invention is to provide a hot water supply device having an instant hot water function with few construction defects and excellent workability.

Means for Solving the Problems

[0008] According to the present invention, inside the casing, a hot water supply side heating means, a heating side heating means, a water supply path connected to the hot water supply side heating means, a hot water supply path connected to the hot water supply side heating means, a heating circulation path connected to the heating side heating means through which the heat medium circulates, a heating circulation pump for circulating the heat medium in the heating circulation path, an instant hot water circulation path connected to the hot water supply path through which hot water circulates during hot water supply stoppage, an instant hot water liquid-to-liquid heat exchanger for heating the hot water circulating in the instant hot water circulation path with the heat medium circulating in the heating circulation path, an instant hot water circulation pump provided in the instant hot water return path of the instant hot water circulation path for sending hot water to the instant hot water liquid-to-liquid heat exchanger and circulating the hot water in the instant hot water circulation path, a water filling path branching from the hot water supply path upstream of the connection portion of the instant hot water forward path of the instant hot water circulation path for sending the hot water heated by the instant hot water liquid-to-liquid heat exchanger to the hot water supply path, a hot water supply path check valve provided in the hot water supply path upstream of the connection portion of the instant hot water forward path and downstream of the connection portion of the water filling path, and having, near the bottom plate of the casing, An instantaneous hot water return check valve installed in the instantaneous hot water return path upstream of the instantaneous hot water circulation pump, and an instantaneous hot water drain cock installed in the instantaneous hot water return path near the instantaneous hot water return check valve, are provided in the hot water supply device.

[0009] According to the above hot water supply device, an instantaneous hot water circulation pump for performing instantaneous hot water operation, an instantaneous hot water liquid-liquid heat exchanger, a check valve in the hot water supply path, etc. are housed in the casing, and the instantaneous hot water return check valve is provided near the bottom plate of the casing. Therefore, the connection process at the installation site can be reduced. Further, according to the above hot water supply device, since the instantaneous hot water drain cock is disposed near the instantaneous hot water return check valve, when bleeding air from the instantaneous hot water circulation path during construction or the like, the instantaneous hot water drain cock can be opened in front of the hot water supply device. Thereby, construction defects can be reduced and workability can be improved.

[0010] Preferably, in the above hot water supply device, the instantaneous hot water drain cock has an instantaneous hot water first drain cock installed in the instantaneous hot water return path upstream of the instantaneous hot water return check valve, and an instantaneous hot water second drain cock installed in the instantaneous hot water return path downstream of the instantaneous hot water return check valve and upstream of the instantaneous hot water circulation pump.

[0011] When bleeding air from the instantaneous hot water circulation path, water flows into the instantaneous hot water circulation path in a direction that is easy to go around with low flow path resistance. Therefore, depending on the arrangement of the water element members provided in the instantaneous hot water circulation path, water may be easier to go around from the instantaneous hot water supply path side than from the instantaneous hot water return path side. Therefore, if a drain cock is provided only on the downstream side of the instantaneous hot water return check valve, the flow of water is blocked by the instantaneous hot water return check valve, and air cannot be bled from the entire instantaneous hot water circulation path, and a long time is required for the work. However, according to the above hot water supply device, by opening the instantaneous hot water first and second drain cocks, water can be made to flow into the instantaneous hot water circulation path from both the instantaneous hot water return path and the instantaneous hot water supply path. Thereby, even when the instantaneous hot water return check valve is arranged in the instantaneous hot water return path and water is easy to go around from the instantaneous hot water supply path side, air can be smoothly bled from the instantaneous hot water circulation path, and workability can be further improved.

Effect of the Invention

[0012] As described above, according to the present invention, it is possible to provide a water supply device having an instant hot water function with less construction defects and excellent workability.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, as an example, a case where the water supply device according to the embodiment of the present invention is applied to a water supply device that executes a water supply operation for supplying hot and cold water to a water supply terminal such as a calan provided in a bathroom or a kitchen, a water filling operation for filling a bathtub with hot water, a heating operation for circulating and supplying hot and cold water to a warm water heating terminal (such as a floor heating device or a warm air heating device), a reheating operation for heating the bath water in the bathtub, and an instant hot water operation for circulating and heating hot and cold water during the stop of the water supply operation will be described.

[0015] FIG. 1 is a schematic configuration diagram showing an example of a water heater according to an embodiment of the present invention. The water heater 1 is installed, for example, in a pipe shaft of an apartment building, and a can body 20 having two heating means is disposed in a casing 10 that communicates with the outside through an air supply port and an exhaust port 7 (not shown). The casing 10 includes a casing main body 10a having a front opening (see FIG. 2) and a cover (not shown) that closes the front opening of the casing main body 10a. In the present embodiment, the front opening side is defined as the front side, the side opposite to the front opening side is defined as the back side, the depth direction when the water heater 1 is viewed from the front side is defined as the front-rear direction, the width direction is defined as the left-right direction, and the height direction is defined as the up-down direction. The inside of the can body 20 is partitioned by a partition portion 21 and is composed of a hot water supply side heating means 30 and a heating / reheating side heating means 40.

[0016] The hot water supply side heating means 30 includes, in order from the bottom, a hot water supply side burner unit 33, a first heat exchanger 31 on the hot water supply side, and a second heat exchanger 32 on the hot water supply side. The first heat exchanger 31 on the hot water supply side recovers sensible heat from the combustion exhaust gas discharged from the hot water supply side burner unit 33, and the second heat exchanger 32 on the hot water supply side recovers latent heat from the combustion exhaust gas discharged from the hot water supply side burner unit 33.

[0017] The hot water supply side heating means 30 includes, as fluid flow paths, a water supply path 90 that communicates with the water supply and is connected to the upstream end of the second heat exchanger 32 on the hot water supply side, and a connection that connects the downstream end of the second heat exchanger 32 on the hot water supply side and the upstream end of the first heat exchanger 31 on the hot water supply side. A path 95, a hot water supply path 100 that communicates with a hot water supply terminal P1 such as a faucet and is connected to the downstream end of the first heat exchanger 31 on the hot water supply side, and a hot water bypass path 105 that bypasses the water supply path 90 and the hot water supply path 100. With this configuration, the water supplied from the water supply to the water supply path 90 is heat-exchanged and heated by the second heat exchanger 32 on the hot water supply side and the first heat exchanger 31 on the hot water supply side by the combustion exhaust gas discharged from the hot water supply side burner unit 33, and the heated hot water is supplied to the hot water supply terminal P1 through the hot water supply path 100. A water supply connection port and a hot water supply connection port for connecting the water supply path 90 and the hot water supply path 100 are provided in the bottom plate 11 (see FIG. 2) of the casing main body 10a.

[0018] In the water supply passage 90, in order from the upstream side, there are provided a water volume sensor 91 for detecting the flow rate of the water flowing through the water supply passage 90, a water supply temperature sensor 92 for detecting the temperature of the water flowing through the water supply passage 90, a water volume servo 93 for changing the opening degree of the water supply passage 90, and a bypass servo 94 for changing the opening degree of a hot water supply bypass passage 105 that communicates the water supply passage 90 and the hot water supply passage 100. These water element members are arranged between the hot water supply side heating means 30 and the instant hot water circulation pump 311 as described later. The flow rate of the water detected by the water volume sensor 91 and the temperature of the water detected by the water supply temperature sensor 92 are output to a control circuit C1 described later. A water outlet passage 96 for guiding the water from the water supply to the hot water supply terminal P1 is branched and connected to the water supply passage 90 on the upstream side of the water volume sensor 91.

[0019] A part of the instant hot water circulation path 300 extends outside the casing 10. The instant hot water circulation path 300 branches from the hot water supply passage 100 outside the casing 10 and has an instant hot water return path 301 for sending hot water to the instant hot water liquid-to-liquid heat exchanger 313 inside the casing 10, and an instant hot water forward path 302 that is branched and connected to the hot water supply passage 100 on the downstream side of the hot water supply bypass passage 105 inside the casing 10 and sends hot water from the instant hot water liquid-to-liquid heat exchanger 313 to the hot water supply passage 100. An instant hot water return connection port for connecting the instant hot water return path 301 is opened on the bottom plate 11 of the casing main body 10a. In the instant hot water return path 301 arranged inside the casing 10, there are provided an instant hot water volume sensor 310, a non-self-priming instant hot water circulation pump 311, an instant hot water temperature sensor 312, and an instant hot water liquid-to-liquid heat exchanger 313. Further, in the instant hot water return path 302 arranged outside the casing 10, there are provided a gas-liquid separator 314, an expansion tank 315, and an overpressure relief valve 316. The flow rate of the hot water detected by the instant hot water volume sensor 310 and the temperature of the hot water detected by the instant hot water temperature sensor 312 are output to a control circuit C1 described later. Note that the non-self-priming pump is smaller than the self-priming pump, and the space inside the casing 10 can be saved.

[0020] In the immediate hot water return path 301 near the lower stream side of the immediate hot water return connection port on the bottom plate 11 of the casing body 10a, in order from the upstream side, an immediate hot water first drain plug 321, an immediate hot water return path check valve 320 that allows the water flow from the immediate hot water return path 301 to the immediate hot water forward path 302 and blocks the backflow from the immediate hot water forward path 302 to the immediate hot water return path 301, and an immediate hot water second drain plug 322 are interposed. Therefore, when the immediate hot water circulation pump 311 is operated in a state where the immediate hot water circulation path 300 is filled with water, the direction in which the hot water flows from the immediate hot water return path 301 to the immediate hot water forward path 302 becomes the forward direction. The immediate hot water first and second drain plugs 321, 322 are each configured to be manually openable and closable. Note that the immediate hot water return path check valve 320 and the immediate hot water first and second drain plugs 321, 322 may be provided near the upper stream side of the immediate hot water return connection port in the casing body 10a.

[0021] The immediate hot water liquid-to-liquid heat exchanger 313 is composed of a plate type heat exchanger in which a planar flow path through which the hot water in the immediate hot water circulation path 300 flows and a planar flow path through which the hot water in the heating branch circulation path 270 branched from the connection return path 206 of the heating circulation path described later flows are laminated. In the immediate hot water liquid-to-liquid heat exchanger 313, heat exchange (liquid-liquid heat exchange) is performed between the hot water flowing in the immediate hot water circulation path 300 and the hot water flowing in the heating branch circulation path 270, and the hot water flowing in the immediate hot water circulation path 300 is heated.

[0022] In the hot water supply path 100, in order from the upstream side, a heat exchange temperature sensor 101 that detects the temperature of the hot water discharged from the hot water supply side first heat exchanger 31 and a hot water discharge temperature sensor 103 that detects the temperature of the hot water supplied downstream of the confluence point with the hot water supply bypass path 105 are provided. The temperatures of the hot water detected by these temperature sensors 101, 103 are output to a control circuit C1 described later.

[0023] Below the hot water supply side burner unit 33, a blower fan 70 is provided. By the operation of the blower fan 70, the air inhaled into the casing 10 is supplied as combustion air to the hot water supply side burner unit 33 and the heating side burner unit 43 described later, and the combustion exhaust gas discharged from the hot water supply side burner unit 33 and the heating side burner unit 43 is discharged from the exhaust port 7. Note that a blower fan may also be provided below the heating side burner unit 43 to supply combustion air to the hot water supply side burner unit 33 and the heating side burner unit 43 individually.

[0024] The hot water supply side burner unit 33 is composed of three hot water supply side burner blocks 33a, 33b, and 33c each having a plurality of burners. Each hot water supply side burner block 33a, 33b, and 33c is connected to a hot water supply side gas branch path 52 branched from a gas supply path (not shown). The gas supply path is provided with an original solenoid valve 51 for opening and closing the gas supply path. The hot water supply side gas branch path 52 is provided with a hot water supply side gas proportional valve 53 for changing the opening degree of the hot water supply side gas branch path 52, and hot water supply side switching valves 54a, 54b, and 54c for individually switching the supply and cutoff of fuel gas to the hot water supply side burner blocks 33a, 33b, and 33c.

[0025] On the downstream side of the connection part of the hot water supply bypass passage 105 and on the upstream side of the connection part of the instant hot water forward passage 302, a hot water filling passage 250 is branched and connected to the hot water supply passage 100. Also, on the upstream side of the connection part of the instant hot water forward passage 302 and on the downstream side of the connection part of the hot water filling passage 250, a hot water supply passage check valve 107 is interposed in the hot water supply passage 100 to allow the water flow from the hot water supply side heating means 30 to the hot water supply terminal P1 and the instant hot water return passage 301 and prevent the backflow to the hot water supply side heating means 30 and the hot water filling passage 250. Therefore, it is possible to prevent the backflow of hot water to the hot water supply side heating means 30, the hot water supply bypass passage 105, and the hot water filling passage 250 on the upstream side of the hot water supply passage check valve 107 from the instant hot water circulation passage 300. Thereby, even if internal leakage occurs in the instant hot water liquid-to-liquid heat exchanger 313 and the contaminated hot water flowing in the heating branch circulation passage 270 flows into the instant hot water circulation passage 300, it is possible to prevent the contamination of the water supply. Also, since the hot water circulating in the instant hot water circulation passage 300 does not flow back into the hot water filling passage 250, even when high-temperature hot water is circulated during the instant hot water operation, it is possible to prevent the rise in the hot water filling temperature. Further, even when leakage occurs in the hot water supply terminal P1 of the mixing faucet and the water from the water supply passage 90 flows into the hot water supply passage 100 through the mixing faucet, the water does not flow back to the hot water outlet temperature sensor 103, so it is possible to prevent the poor temperature control in the hot water supply operation and the hot water filling operation. Note that, in order to prevent the backflow of hot water to the water supply, a check valve may be further provided in the water supply passage 90 on the upstream side of the connection part of the hot water supply bypass passage 105.

[0026] The hot water filling passage 250 communicates with a bath return passage 251 connected to the bathtub P2. The bath return passage 251, together with the bath forward passage 252, constitutes a bath circulation passage between the bathtub P2 and the bath liquid-to-liquid heat exchanger 221. A bath connection port for connecting these bath return passage 251 and bath forward passage 252 is opened in the bottom plate 11 of the casing main body 10a.

[0027] In the hot water filling path 250, in order from the upstream side, there are provided a hot water filling solenoid valve 261 for opening and closing the hot water filling path 250, a check valve 263 for preventing the backflow of hot water from the hot water filling path 250 to the hot water supply path 100, and a hot water filling water flow sensor 262 for detecting the flow rate of the hot water supplied from the hot water supply path 100 to the hot water filling path 250. The flow rate of the hot water detected by the hot water filling water flow sensor 262 is output to a control circuit C1 described later.

[0028] In the bath return path 251, there are provided a bath return temperature sensor 225 for detecting the temperature of the hot water flowing into the bath return path 251 from the bathtub P2, a bath circulation pump 224 for circulating the hot water in the bathtub P2 through the bath forward path 252 and the bath return path 251, a water level sensor 223 for detecting the water level of the hot water in the bathtub P2, and a bath water flow switch 222 for detecting that hot water with a predetermined flow rate or more is flowing in the bath return path 251. Further, in the bath forward path 252, there is provided a bath forward temperature sensor 226 for detecting the temperature of the hot water flowing out of the bath liquid-to-liquid heat exchanger 221 to the bathtub P2. The flow rate and temperature of the bath water detected by these sensors are output to a control circuit C1 described later. By operating the bath circulation pump 224, bath water circulates in a bath circulation path connecting the bathtub P2 and the bath liquid-to-liquid heat exchanger 221.

[0029] In the heating and reheating side heating means 40, in order from the bottom, there are arranged a heating side burner unit 43, a first heating side heat exchanger 41, and a second heating side heat exchanger 42. The first heating side heat exchanger 41 recovers sensible heat from the combustion exhaust discharged from the heating side burner unit 43, and the second heating side heat exchanger 42 recovers latent heat from the combustion exhaust discharged from the heating side burner unit 43.

[0030] The heating and post - combustion side heating means 40 includes, as fluid flow paths, a heating return path 200 connected to the upstream end of the second heat exchanger 42 on the heating side, a heating supply path 210 connected to the downstream end of the first heat exchanger 41 on the heating side, a communication supply path 205 and a communication return path 206 that connect the downstream end of the second heat exchanger 42 on the heating side and the upstream end of the first heat exchanger 41 on the heating side with the cistern 201 interposed therebetween, a bath branch path 240 that branches from the heating supply path 210 and is connected to the heating return path 200, and a heating branch circulation path 270 that branches from the communication return path 206 and is connected to the bath branch path 240. Therefore, in the present embodiment, a heating circulation path is constituted by these fluid flow paths.

[0031] Although not shown, a makeup water path that branches from the water supply path 90 and replenishes water to the cistern 201 is connected to the cistern 201. A makeup water solenoid valve 203 is provided at the connection portion between the cistern 201 and the makeup water path. By opening the makeup water solenoid valve 203, the water introduced from the water supply to the water supply path 90 is supplied to the cistern 201.

[0032] The heating supply path 210 is connected to a high - temperature heating terminal (such as a warm - air heater) P3. A heating circulation pump 211 for circulating hot water between the high - temperature heating terminal P3 and the heating and post - combustion side heating means 40 is provided in the communication return path 206. Further, a low - temperature branch path 216 branches from an intermediate portion on the downstream side of the heating circulation pump 211 in the communication return path 206 and is connected to a thermostatic valve header 212 for connecting a low - temperature heating terminal (such as a floor heater) P4. Also, the heating branch circulation path 270 branches from a position more downstream than the low - temperature branch path 216 in the communication return path 206. In the heating branch circulation path 270, an instantaneous hot water flow rate control valve 271 for changing the opening degree of the heating branch circulation path 270 and the above - mentioned instantaneous hot water - to - liquid heat exchanger 313 are interposed.

[0033] The return path 200 for the heating system has a heating return path 217 connected to it for returning the hot water from the low-temperature heating terminal P4. With this configuration, by operating the heating circulation pump 211, the hot water flowing through the heating return path 200 is heat-exchanged and heated by the combustion exhaust gas discharged from the heating-side burner unit 43 in the heating-side second heat exchanger 42 and the heating-side first heat exchanger 41. The heated hot water (heat medium) is circulated and supplied from the heating supply path 210 to each heating terminal P3, P4, the bath liquid-to-liquid heat exchanger 221, and the instant hot water liquid-to-liquid heat exchanger 313. On the bottom plate 11 of the casing body 10a, there are heating connection ports for connecting these heating return path 200, heating supply path 210, low-temperature branch path 216, and heating return path 217.

[0034] The heating supply path 210 is provided with a heating high-temperature temperature sensor 213 for detecting the temperature of the hot water discharged from the heating-side first heat exchanger 41, and the communication supply path 206 is provided with a heating low-temperature temperature sensor 215 for detecting the temperature of the hot water supplied from the cistern 201 to the low-temperature branch path 216. The temperatures of the hot water detected by these temperature sensors 213, 215 are output to the control circuit C1 described later.

[0035] The heating-side burner unit 43 is composed of two burner blocks 43a, 43b each having a plurality of burners, and each burner block 43a, 43b is connected to a heating-side gas branch path 60 branched from the gas supply path. The heating-side gas branch path 60 is provided with a heating-side gas proportional valve 61 for changing the opening degree of the heating-side gas branch path 60, and heating-side switching valves 62a, 62b for individually switching the supply and cutoff of the fuel gas to the burner blocks 43a, 43b. Therefore, by selectively opening and closing the heating-side switching valves 62a, 62b, the heating-side burner unit 43 can be switched to any one of the capacity stages with different combustion amount ranges.

[0036] Branching off from the hot water supply forward path 210 and in the middle of the bathtub branch path 240 connected to the hot water supply return path 200, the above-described bathtub liquid-to-liquid heat exchanger 221 is provided. The bathtub liquid-to-liquid heat exchanger 221 is composed of a plate-type heat exchanger in which a planar flow path through which bathtub water from the bathtub return path 251 flows and a planar flow path through which hot water from the hot water supply forward path 210 flows are laminated. In the bathtub liquid-to-liquid heat exchanger 221, heat exchange (liquid-liquid heat exchange) is performed between the hot water flowing in the bathtub forward path 252 and the hot water flowing in the bathtub branch path 240, and the hot water flowing in the bathtub forward path 252 is heated. In the bathtub branch path 240, a supplementary heating flow control valve 220 for changing the opening degree of the bathtub branch path 240 is provided. If it is manufactured from plates of the same configuration except that the number of plates laminating the instant hot water liquid-to-liquid heat exchanger 313 and the bathtub liquid-to-liquid heat exchanger 221 is different, cost reduction can be achieved.

[0037] Inside the can body 20, a drain receiver 16 is provided to receive the strongly acidic drain generated on the surfaces of the hot water supply side second heat exchanger 32 and the heating side second heat exchanger 42. Although not shown, at the bottom of the drain receiver 16, a drain outlet pipe for guiding the above drain to the drain neutralizer 17 is connected. Also, inside the drain neutralizer 17, a drain neutralizing agent is loaded, and the drain collected in the drain neutralizer 17 through the drain outlet pipe is neutralized by the drain neutralizing agent. A drain pump 37 for forcibly discharging the neutralized water of the drain collected in the drain neutralizer 17 to the outside is connected to the drain neutralizer 17.

[0038] A control circuit C1 incorporated in a casing 10 is connected by wire or wirelessly to a remote controller (not shown) provided in a kitchen, a bathroom, or the like. The user can operate the remote controller to set the hot water supply temperature in the hot water supply operation, the hot water filling temperature in the hot water filling operation, the heating temperature in the heating operation, the reheating temperature in the reheating operation, and the like. Also, the operator can operate the remote controller during construction or the like to execute a trial operation and make settings according to the installation location. Although not shown, the control circuit C1 is connected through electrical wiring to a fan motor of a blower fan 70, an original solenoid valve 51, a hot water supply side gas proportional valve 53, hot water supply side switching valves 54a, 54b, 54c, a heating side gas proportional valve 61, heating side switching valves 62a, 62b, an ignition electrode that generates a spark discharge near each flame hole of a hot water supply side burner unit 33 and a heating side burner unit 43, a flame detection sensor that detects ignition of the hot water supply side burner unit 33 and the heating side burner unit 43, a water volume sensor 91, a hot water temperature sensor 92, a water volume servo 93, a bypass servo 94, a make-up water solenoid valve 203, a hot water filling solenoid valve 261, a hot water filling water volume sensor 262, a reheating flow control valve 220, a heating circulation pump 211, a thermostatic valve 212, a bath water flow switch 222, a water level sensor 223, a bath circulation pump 224, a water level electrode of a cistern 201, a heat exchanger temperature sensor 101, a hot water outlet temperature sensor 103, a heating high temperature temperature sensor 213, a heating low temperature temperature sensor 215, a bath return temperature sensor 225, a bath supply temperature sensor 226, an instant hot water circulation pump 311, an instant hot water volume sensor 310, an instant hot water flow control valve 271, an instant hot water temperature sensor 312, and a drain pump 37.

[0039] The control circuit C1 includes a CPU, a memory, an interface circuit, etc. (not shown), and is constituted by one circuit board 5 below in the casing 10 (see Fig. 2). The control circuit C1 functions to control the overall operation of the water heater 1 by the CPU executing the control program of the water heater 1 stored in the memory. Therefore, the hot water supply operation, the heating operation, the water filling operation, the reheating operation, and the instant hot water operation can be controlled by one circuit board 5, and the space in the casing 10 can be saved. Also, since there is no need to connect the circuit board of the circulation device manufactured as a separate unit to provide the instant hot water function as in the prior art and the circuit board in the casing 10, construction mistakes when connecting the circuit boards can be prevented. Further, regardless of the presence or absence of the instant hot water function, the hot water supply operation and the heating operation have a common configuration, so the common circuit board 5 can be used for both the water heater with the instant hot water function and the water heater without the instant hot water function. Thereby, the productivity of the circuit board 5 can be improved.

[0040] Fig. 2 is an external view showing an example of the water heater according to the present embodiment, Fig. 3 is a perspective view of the main part seen from the front side, Fig. 4 is a perspective view of the main part seen from the back side, and Fig. 5 is a perspective view of the main part showing a part of the bottom surface. Note that, to avoid complication, some elements are omitted in these drawings.

[0041] The hot water supply device 1 includes a substantially rectangular box-shaped casing body 10a having a front opening, and a cover (not shown). A can body 20 in which hot water supply side heating means 30 and heating / supplementary heating side heating means 40 are housed is disposed above the casing body 10a. The can body 20 is composed of, in order from the bottom, a combustion chamber 2 in which the above-described hot water supply side burner unit 33 and heating side burner unit 43 are housed, a first heat exchange chamber 3 in which the hot water supply side first heat exchanger 31 and heating side first heat exchanger 41 are housed, and a second heat exchange chamber 4 in which the hot water supply side second heat exchanger 32 and heating side second heat exchanger 42 are housed, which are laminated. A blower fan 70 is connected to the opening below the combustion chamber 2. Also, when viewed from the front, the downstream end of the water supply path 90 and the upstream end of the connecting path 95 are connected to the right region of the second heat exchange chamber 4, and the upstream end of the hot water supply path 100 and the downstream end of the connecting path 95 are connected to the right region of the first heat exchange chamber 3. Although not shown, the downstream end of the heating return path 200 and the upstream end of the communication forward path 205 are connected to the left region of the second heat exchange chamber 4, and the upstream end of the heating forward path 210 and the downstream end of the communication return path 206 are connected to the left region of the first heat exchange chamber 3.

[0042] On the upper surface of the bottom plate 11 of the casing body 10a, an immediate hot water circulation pump 311, a drain pump 37, and a bath circulation pump 224 are fixedly connected by fixing screws in order from the right side. Near the left end of the upper surface of the bottom plate 11, a heating circulation pump 211 is fixedly connected via a fixing member.

[0043] Although not shown, a plurality of the above-described connection ports are opened in the bottom plate 11 of the casing body 10a. The water supply path 90 and the hot water supply path 100 extend downward from the can body 20. The lower ends of the pipes of the water supply path 90 and the hot water supply path 100 and the lower end of the pipe of the immediate hot water return path 301 disposed in the casing 10 are respectively connected to a water supply connection port, a hot water supply connection port, and an immediate hot water return connection port opened in the bottom plate 11 of the casing body 10a. A hot water supply check valve 107 is provided in the hot water supply path 100 above the connection portion of the immediate hot water forward path 302 near the bottom plate 11.

[0044] As shown in Fig. 5, various connection parts for connecting pipes outside the casing 10 are provided on the lower surface of the bottom plate 11 of the casing body 10a. Specifically, a direct hot water return connection part 401 to which the pipe of the direct hot water return path 301 is connected is provided in front of the right region of the lower surface of the bottom plate 11, and a water supply connection part 402 and a hot water supply connection part 403 to which the pipes of the water supply path 90 and the hot water supply path 100 are connected are provided behind the right region of the lower surface of the bottom plate 11. Further, a gas connection part 404 to which the pipe of the gas supply path is connected is provided in front of the left and right central regions of the lower surface of the bottom plate 11, and a bath connection part 405 to which the pipes of the bath return path 251 and the bath forward path 252 are connected is provided behind the left and right central regions of the lower surface of the bottom plate 11. Although not shown, a heating connection part to which a pipe such as the heating return path 200 is connected is provided in the left region of the lower surface of the bottom plate 11.

[0045] The direct hot water return connection part 401 provided adjacent to the lower side of the bottom plate 11 is configured by integrating the above-described direct hot water return path check valve 320 and the first and second direct hot water drain plugs 321, 322. Therefore, these drain plugs 321, 322 can be easily opened and closed from below the water heater 1.

[0046] Water element members such as the above-described water volume sensor 91 and bypass servo 94 are interposed in the water supply path 90. These water element members are disposed below the can body 20 and above the direct hot water circulation pump 311. Further, a flat substantially rectangular direct hot water liquid-to-liquid heat exchanger 313 is disposed in a standing state below the can body 20 and at the rear central portion so that the thickness direction is in the front-rear direction. Further, a flat substantially rectangular bath liquid-to-liquid heat exchanger 221 is disposed horizontally above the direct hot water liquid-to-liquid heat exchanger 313 below the can body 20 so that the thickness direction is in the vertical direction.

[0047] A cistern 201 is disposed on the left side of the can body 20 in the casing body 10a. The above-described drain neutralizer 17 is disposed in the front lower left in the casing body 10a. The circuit board 5 constituting the above-described control circuit C1 is disposed in the front lower right in the casing body 10a.

[0048] According to the present embodiment, since the instant hot water circulation pump 311, the instant hot water-to-liquid heat exchanger 313, etc. for performing instant hot water operation are housed in the casing 10, there is no need to connect a circulation device of a separate unit to the water heater at the installation site as in the prior art. Therefore, the connection process at the installation site can be reduced, and construction defects can be reliably reduced.

[0049] Also, according to the present embodiment, the check valve 107 for the hot water supply path to prevent the backflow of hot water to the water supply or the hot water filling path 250 is disposed in the casing 10, and the instant hot water return path check valve 320 is disposed near the bottom plate 11 of the casing main body 10a. Therefore, it is possible to prevent connection in the wrong connection direction at the installation site, and construction defects can be reliably reduced. Further, since the hot water supply path check valve 107 is provided in the hot water supply path 100 in the casing 10, a common pipe can be used for both a water heater having an instant hot water function and a water heater without an instant hot water function. Also, the check valve provided in the water supply path 90 can be omitted.

[0050] Also, according to the present embodiment, since the instant hot water first and second drain plugs 321 and 322 are disposed near the bottom plate 11, when bleeding air from the instant hot water circulation path 300 during construction or the like, the operator can perform the work in front of the water heater 1.

[0051] Also, when bleeding air from the instant hot water circulation path 300, water flows into the instant hot water circulation path 300 in a direction that is easy to flow around and has low flow resistance. Therefore, when a water element member such as a gas-liquid separator 314 is provided in the instant hot water return path 301, water can flow around more easily from the instant hot water forward path 302 side than from the instant hot water return path 301 side. Therefore, if a drain plug is provided only on the downstream side of the instant hot water return path check valve 320, the flow of water is blocked by the instant hot water return path check valve 320, and air cannot be bled from the entire instant hot water circulation path 300, and the work takes a long time. However, according to the present embodiment, if the instant hot water first and second drain plugs 321 and 322 are opened during construction or the like, water can be made to flow into the instant hot water circulation path 300 from both pipelines of the instant hot water return path 301 and the instant hot water forward path 302 by the water supply pressure. Thereby, even when the instant hot water return path check valve 320 is arranged in the instant hot water return path 301 and water can flow around easily from the instant hot water forward path 302 side, air can be bled from the instant hot water circulation path 300 smoothly, and workability can be further improved.

[0052] Also, according to the present embodiment, since the instant hot water circulation pump 311, the instant hot water liquid-to-liquid heat exchanger 313, etc. are housed in the casing 10, the devices arranged outside the hot water supply device 1 can be reduced. Thereby, even when an instant hot water function is added to a hot water supply device having a hot water supply function and a heating function, the hot water supply device 1 can be installed in a narrow accommodation space, and the difficulty of construction can be reduced.

[0053] Also, according to the present embodiment, since the hot water flowing through the instant hot water circulation path 300 is heated by the hot water flowing through the heating branch circulation path 270 that forms a part of the heating circulation path, it is not necessary to operate the hot water supply side heating means 30 with high capacity to execute the instant hot water operation, and the instant hot water operation can be executed efficiently. Note that an antifreeze liquid may be used as the heat medium for heating.

[0054] Also, according to the present embodiment, the instant hot water-to-liquid heat exchanger 313 and the bath water-to-liquid heat exchanger 221 are composed of plate heat exchangers. Even in the water heater 1 having not only a hot water supply function and a heating function but also a bath reheating function, the instant hot water circulation pump 311 and the instant hot water-to-liquid heat exchanger 313 can be accommodated in the casing 10, and the construction difficulty can be reduced.

Explanation of Signs

[0055] 1 Water heater 10 Casing 11 Bottom plate 30 Hot water supply side heating means 40 Heating / reheating side heating means 90 Water supply line 100 Hot water supply line 107 Hot water supply line check valve 300 Instant hot water circulation line 301 Instant hot water return line 302 Instant hot water supply line 311 Instant hot water circulation pump 313 Instant hot water-to-liquid heat exchanger 320 Instant hot water return line check valve 321 First instant hot water drain plug 322 Second instant hot water drain plug

Claims

1. Inside the casing, a hot water supply side heating means, a heating side heating means, a part of the water supply path connected to the hot water supply side heating means, a part of the hot water supply path connected to the hot water supply side heating means, a part of the heating circulation path connected to the heating side heating means through which the heat medium circulates, a heating circulation pump for circulating the heat medium in the heating circulation path, a part of the instant hot water circulation path connected to the hot water supply path through which the hot water and water circulate during hot water supply stop, an instant hot water - liquid heat exchanger for heating the hot water and water circulating in the instant hot water circulation path with the heat medium circulating in the heating circulation path, an instant hot water circulation pump provided in the instant hot water return path of the instant hot water circulation path for sending the hot water and water to the instant hot water - liquid heat exchanger and circulating the hot water and water in the instant hot water circulation path, a water filling path branching from the hot water supply path upstream of the connection part of the instant hot water forward path of the instant hot water circulation path for sending the hot water heated by the instant hot water - liquid heat exchanger to the hot water supply path, a hot water supply path check valve provided in the hot water supply path upstream of the connection part of the instant hot water forward path and downstream of the connection part of the water filling path, Near the bottom plate of the casing, an instant hot water return path check valve provided in the instant hot water return path upstream of the instant hot water circulation pump, an instant hot water drain plug provided in the instant hot water return path near the instant hot water return path check valve, a hot water supply device having the same.

2. In the hot water supply device according to Claim 1, the instant hot water drain plug has an instant hot water first drain plug provided in the instant hot water return path upstream of the instant hot water return path check valve and an instant hot water second drain plug provided in the instant hot water return path downstream of the instant hot water return path check valve and upstream of the instant hot water circulation pump, a hot water supply device having the same.

Images