Hot water supply device

Abstract

To detect an open failure of a check valve for backflow prevention of low temperature water.SOLUTION: A mixing valve 340 outputs hot water in which high temperature water from a high temperature water pipeline 119a and low temperature water from a low temperature water pipeline 111 are mixed to a hot water tapping pipeline 121. At the low temperature water pipeline 111, a check valve 55 which has a checking function for inhibiting a flow from the mixing valve 340 toward a water supply end 101 is interposed and connected. A temperature detector 510 is arranged in a path of low temperature water between the water supply end 101 and the check valve 55. When a detection temperature by the temperature detector 510 rises above a reference temperature set according to the temperature of the low temperature water introduced into the water supply end 101, an open failure is detected in which the checking function of the check valve 55 is lost.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hot water supply system, and more particularly to a hot water supply device that mixes hot water and cold water to supply hot water.

Background Art

[0002] A hot water supply system that controls the hot water outlet temperature with a mixing valve for hot water and cold water is known. For example, Japanese Patent No. 4264081 (Patent Document 1) describes a storage type hot water supply device having a configuration in which hot water in the hot water outlet pipe and cold water in the water supply pipe are mixed by a hot water supply mixing valve and output to the hot water supply pipe.

[0003] In Patent Document 1, a check valve for allowing the flow of hot and cold water only in the direction toward the hot water supply mixing valve is provided in the water supply pipe. Further, as a failure determination function of the check valve, it is described that a blockage failure of the check valve is detected using the flow rate detection value of the hot water supply pipe under the condition that the hot water supply mixing valve is fully opened with cold water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generally, the check valve function of a check valve is generally realized by the operation of a mechanical structure in response to the application of a water supply pressure, rather than by electronic control by a controller. For this reason, it is difficult to simply detect an open failure in which the check valve function is lost by directly monitoring the operating state of the check valve.

[0006] On the other hand, Patent Document 1 does not disclose or suggest the detection of an open failure of a check valve arranged in a water supply pipe.

[0007] The present invention has been made to solve such problems, and an object thereof is to realize a detection function for an open failure of a check valve disposed in a pipe that guides low-temperature water to a mixing valve in a hot water supply apparatus having a configuration including a mixing valve for high-temperature water and low-temperature water.

Means for Solving the Problems

[0008] According to an aspect of the present invention, a hot water supply apparatus is provided. The hot water supply apparatus includes a high-temperature water pipe that supplies high-temperature water, a low-temperature water pipe that supplies low-temperature water from a water supply end, a hot water outlet pipe that is connected to a hot water outlet end, a mixing valve, a control device, a check valve, and a temperature detector. The mixing valve has a first port connected to the high-temperature water pipe, a second port connected to the low-temperature water pipe, and a third port connected to the hot water outlet pipe. The control device controls a mixing ratio of the hot water flowing from the first port to the third port and the hot water flowing from the second port to the third port according to the opening degree of the mixing valve. The check valve is inserted and connected to the low-temperature water pipe and has a check function of preventing the flow from the second port toward the water supply end. The temperature detector is disposed in a path of the low-temperature water between the water supply end and the check valve. The control device includes a failure diagnosis unit. The failure diagnosis unit detects an open failure in which the check function of the check valve is lost when the detected temperature by the temperature detector rises above a reference temperature set according to the temperature of the low-temperature water introduced into the water supply end.

Effects of the Invention

[0009] According to the present invention, in a hot water supply apparatus having a configuration including a mixing valve for high-temperature water and low-temperature water, an open failure of a check valve disposed in a pipe that guides low-temperature water to the mixing valve can be detected using a temperature detection value on the upstream side of the check valve.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

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Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

[0012] (Configuration Example of the Water Heater) FIG. 1 is a block diagram for explaining a configuration example of the water heater according to the present embodiment.

[0013] Referring to FIG. 1, the water heater 10 according to the present embodiment is shown as a hot - water storage and supply device including a hot - water storage tank 150 stored in a housing 25. As will be described later, high - temperature water heated by a heat - generating mechanism (not shown) provided outside the water heater 10 is stored in the hot - water storage tank 150. Typically, the heat - generating mechanism can be constituted by a heat - generating mechanism that generates waste heat such as a fuel cell or an engine generator, or a heat pump device.

[0014] The hot water supply device 10 further includes a water supply end 101, a hot water outlet end 102, connection ends 103 to 110 to the outside, an auxiliary heat source machine (BU heat source machine) 200, heat exchangers 210 and 220, a heating tank 230, a heating pump 240, and circulation pumps 310 and 315. The water supply end 101, the hot water outlet end 102, and the connection ends 103 to 110 are configured to be able to connect pipes from the outside of the housing 25.

[0015] FIG. 2 shows a conceptual diagram for explaining the connection relationship between the hot water supply device 10 and other external devices.

[0016] Referring to FIGS. 1 and 2, the water supply end 101 is connected to a water supply pipe 81 that supplies low-temperature water. The hot water outlet end 102 is connected to a hot water supply pipe 80. A hot water tap 15 is connected to the hot water supply pipe 80. When the hot water tap 15 is operated (opened), the appropriately heated hot water output from the hot water supply device 10 to the hot water outlet end 102 is supplied to the hot water tap 15 via the hot water supply pipe 80. The fuel gas pipe 82 supplies the fuel gas burned by the auxiliary heat source machine 200 to the hot water supply device 10.

[0017] The connection end 105 is connected to both the heating device 14a and the bathroom heating and drying machine 14b. The connection end 106 is connected to the heating device 14a, and the connection end 107 is connected to the bathroom heating and drying machine 14b. By the operation of the heating pump 240, a first heating circulation path passing through the heating device 14a and a second heating circulation path passing through the bathroom heating and drying machine 14b can be formed. The second heating circulation path extends from the connection end 105, passes through the heating tank 230, the heating pump 240, the secondary side (not shown) of the heat exchanger 210, and the connection end 107, and reaches the bathroom heating and drying machine 14b. Therefore, high-temperature water heated by the heat exchanger 210 is supplied to the bathroom heating and drying machine 14b.

[0018] On the other hand, the first heating circulation path extends from the connection end 105, passes through the heating tank 230, the heating pump 240, and the connection end 106, and reaches the heating device 14a. Therefore, the high-temperature water supplied to the heating device 14a is not directly heated by the heat exchanger 210 inside the hot water supply device 10.

[0019] That is, by sharing the heat exchanger 210, it is possible to form a circulation path of high-temperature water (heat medium) that serves as a heat source for heating during the operation of the heating device 14a and during the operation of the bathroom heating and drying machine 14b. In the following, the operations of the heating device 14a and the bathroom heating and drying machine 14b are also collectively referred to as heating operations. The heating operation includes cases where both the heating device 14a and the bathroom heating and drying machine 14b are operated.

[0020] Similarly, the connection ends 108 and 109 are connected to the bathtub 13. By the operation of a pump (not shown) built into the water supply device 10, the bathtub water input from the connection end 108 to the water supply device 10 can form a circulation path of the bathtub water that returns to the bathtub 13 via the connection end 109 after passing through the secondary side (not shown) of the heat exchanger 220. Thereby, the reheating operation in the bathtub 13 can be realized. Further, the connection end 110 is connected to the drain pipe 85.

[0021] The remote controller 30 is an input device for operating the water supply device 10, which is arranged in the kitchen, bathroom, etc. The remote controller 30 includes a display unit 31 for outputting information in a manner visible to the user, an operation switch 32 for operating the on / off of the operation of the water supply device 10, an operation unit 33 for receiving input setting operations by the user, etc., and a speaker 34. The display unit 31 is typically composed of a liquid crystal panel and is configured to be able to display various information in a manner visible to the user. The operation unit 33 is typically composed of push buttons or touch buttons and is configured to be able to receive setting operations of the water supply device 10 typified by the set water supply temperature. The speaker 34 outputs sounds, melodies, alarm sounds, etc. that can be recognized by the user aurally.

[0022] Referring to FIG. 1 again, the water supply device 10 further includes a controller 20, pipes 111 to 114, 116 to 119, 119a, 119b, 121, 124 to 126, 130, 132, on-off valves 215, 225, a three-way valve 320, a heat storage switching valve 330, a mixing valve 340, a proportional valve 350, a pouring on-off valve 360, a flow rate adjustment valve 370, and a hot water storage switching valve 380.

[0023] The three-way valve 320, the mixing valve 340, the proportional valve 350, the flow control valve 370, and the hot water storage switching valve 380 each have a stepping motor 321, 341, 351, 371, and 381. By driving the stepping motors 321, 341, 351, 371, and 381 according to control commands from the controller 20, the opening degrees of the three-way valve 320, the mixing valve 340, the proportional valve 350, the flow control valve 370, and the hot water storage switching valve 380 are controlled respectively.

[0024] The first end of the pipe 111 is connected to the water supply end 101 to receive the supply of low-temperature water. The second end of the pipe 111 is connected to the low-temperature side port of the mixing valve 340. Hereinafter, the pipe 111 is also referred to as the low-temperature water pipe 111. A check valve 55 for preventing the backflow of low-temperature water is inserted and connected to the low-temperature water pipe 111. That is, the check valve 55 has a check function of blocking the flow from the mixing valve 340 (low-temperature side port) to the water supply end 101 side.

[0025] The pipe 112 is connected between the low-temperature water pipe 111 and the heat storage switching valve 330. A check valve 56 for preventing the backflow of low-temperature water from the pipe 112 to the low-temperature water pipe 111 is inserted and connected to the pipe 112.

[0026] The first end of the pipe 114 is connected to the primary side paths (not shown) of the heat exchangers 210 and 220 via the on-off valves 215 and 225 respectively. The second end of the pipe 114 is connected to the three-way valve 320. The pipe 113 connects between the heat storage switching valve 330 and the bottom of the hot water storage tank 150. The pipe 116 is connected between the heat storage switching valve 330 and the pipe 114.

[0027] The heat storage switching valve 330 selectively forms one of the tank water inlet path between the pipes 112 and 113, the circulation side path between the pipes 112 and 116, and the tank water inlet and drainage path between the pipes 113 and 116 according to the control command from the controller 20.

[0028] When the heat storage switching valve 330 forms the tank water inlet path, cold water is introduced into the hot water storage tank 150 via the pipes 111 to 113 by the water supply pressure of the water supply pipe 81 (Figure 2) until the hot water storage tank 150 is full.

[0029] The upper part of the hot water storage tank 150 is connected to the pipes 125 and 130. The pipe 130 is connected to the pipe 119a described later. The pipe 125 is connected to the pipe 124 leading to the connection end 103 with a heat generating mechanism (not shown) via the hot water storage switching valve 380. A pipe 126 leading to the connection end 104 with a heat generating mechanism (not shown) is further connected to the bottom of the hot water storage tank 150. A plurality of temperature sensors 151 to 156 are arranged at different parts of the hot water storage tank 150.

[0030] The hot water storage switching valve 380 selectively forms a bypass path that bypasses the hot water storage tank 150 and connects the pipes 124 and 126, and a hot water storage path that connects the pipes 124 and 125 according to the opening degree control by the controller 20 using the stepping motor 381 as a drive source. Temperature sensors 560 and 565 are respectively provided in the pipes 124 and 126.

[0031] By the operation of the circulation pump 315, a heating circulation path can be formed in which the cold water in the hot water storage tank 150 is output to the heat generating mechanism via the connection end 104 and introduced from the connection end 103 as high-temperature water heated by the heat generating mechanism. The circulation pump 315 can also be arranged outside the housing 25 (for example, inside the heat generating mechanism).

[0032] When the hot water storage switching valve 380 forms the hot water storage path during the operation of the circulation pump 315, the high-temperature water heated by the heat generating mechanism is introduced into the hot water storage tank 150. As a result, the temperature in the hot water storage tank 150 rises from the upper part. On the other hand, when the hot water storage switching valve 380 forms the bypass path, the high-temperature water output from the connection end 104 is reheated by the heat generating mechanism without being introduced into the hot water storage tank 150. For example, based on the detected temperature by the temperature sensor 560 (the input temperature from the connection end 103), the bypass path can be formed by the hot water storage switching valve 380 at low temperatures.

[0033] On the other hand, when it is detected by the detected temperatures of the temperature sensors 151 to 156 and 565 that the heating of the high-temperature water in the hot water storage tank 150 is completed, the formation of the heating circulation path is stopped by stopping the circulation pump 315. Thus, in the water supply device 10, with an external heat generating mechanism as the "main heat source", the high-temperature water heated by the main heat source is accumulated in the hot water storage tank 150 and used for water supply.

[0034] The pipe 117 is connected between the three-way valve 320 and the suction port 311a of the circulation pump 310. The three-way valve 320 is further connected to the pipe 130 from the upper part of the hot water storage tank 150 by a pipe 132 provided with a check valve 322.

[0035] The three-way valve 320 controls the flow rate ratio between the path P1 from the pipe 132 to the suction port 311a of the circulation pump 310 and the path P2 from the pipe 114 to the suction port 311a of the circulation pump 310 in accordance with the opening degree control by the controller 20 having the stepping motor 321 as a drive source. By controlling the opening degree of the three-way valve 320, the flow rate ratio can be controlled between 0 and 100 (%), so that both the state where only the path P1 or the path P2 is formed and the state where both the paths P1 and P2 are formed can be realized. Hereinafter, the path P1 is also referred to as the "tank output path", and the path P2 is also referred to as the "circulation path".

[0036] The pipe 118 is connected to the discharge port 311b of the circulation pump 310 and the input end 201a of the auxiliary heat source machine 200. A flow rate sensor 420 is arranged in the pipe 118. The flow rate sensor 420 can detect the passing flow rate of the auxiliary heat source machine 200. The output end 201b of the auxiliary heat source machine 200 is connected to the pipe 119.

[0037] During operation, the auxiliary heat source unit 200 heats the fluid (hot water) introduced from the pipe 118 to the input end 201a using the combustion heat of fuel, and outputs high-temperature water from the output end 201b to the pipe 119. A temperature sensor 550 for detecting the input temperature to the auxiliary heat source unit 200 is arranged in the pipe 118. A temperature sensor 555 for detecting the output temperature from the auxiliary heat source unit 200 is arranged in the pipe 119. The auxiliary heat source unit 200 corresponds to an embodiment of the "heat source unit".

[0038] The pipe 119 branches at the node Nb into a pipe 119a leading to the high-temperature side port of the mixing valve 340 and a pipe 119b leading to the primary sides (not shown) of the heat exchangers 210 and 220.

[0039] During the heating operation, by operating the circulation pump 310 and opening the on-off valve 215, a "high-temperature water circulation path" including the auxiliary heat source unit 200, the pipes 119, 119b, the heat exchanger 210, the pipes 114, 117, the circulation pump 310, and the pipe 118 can be formed. Thereby, when the auxiliary heat source unit 200 is operating, the fluid (heating heat medium) in the circulation path formed between the heating device 14a and / or the bathroom heating and drying machine 14b and the heat exchanger 210 (secondary side) can be heated by the high-temperature water from the auxiliary heat source unit 200.

[0040] Similarly, during the post-combustion operation, by operating the auxiliary heat source unit 200 and opening the on-off valve 225 along with the operation of the circulation pump 310, a high-temperature water circulation path including the auxiliary heat source unit 200, the pipes 119, 119b, the heat exchanger 220, the pipes 114, 117, the circulation pump 310, and the pipe 118 can be formed. Thereby, the bath water flowing through the circulation path between the heat exchanger 220 (secondary side) and the bathtub 13 can be heated by the high-temperature water from the auxiliary heat source unit 200. The temperature sensor 590 can detect the temperature of the high-temperature water after passing through the heat exchangers 210 and 220 (primary side).

[0041] On the other hand, when both the on-off valves 215 and 225 are closed, the high-temperature water circulation path via the pipe 119b is not formed.

[0042] The pipe 119a is connected to the pipe 130 from the hot water storage tank 150 at the node Nc located downstream of the node Nb. Further, a proportional valve 350 is disposed between the node Nb and the node Nc included in the circulation path formed when the circulation pump 310 operates. The opening degree of the proportional valve 350 is controlled by the controller 20 using the stepping motor 351 as a drive source.

[0043] By controlling the opening degree of the proportional valve 350, the flow rate of the high-temperature water output for hot water supply from the pipe 119 via the pipe 119a to the mixing valve 340 can be controlled. Hereinafter, the pipe 119a is also referred to as the high-temperature water pipe 119a.

[0044] In particular, in a state where the on-off valves 215 and / or 225 are open, the ratio between the flow rate (for hot water supply) to the mixing valve 340 via the high-temperature water pipe 119a and the flow rate (for heating / reheating) to the circulation path including the pipe 119b of the high-temperature water from the auxiliary heat source machine 200 can be controlled by the opening degree of the proportional valve 350. Note that it is also possible to set the proportional valve 350 to be fully closed (opening degree = 0) and use the entire amount of the high-temperature water from the auxiliary heat source machine 200 for heating / reheating.

[0045] The output end of the mixing valve 340 is connected to the pipe 121 leading to the hot water outlet end 102. Hereinafter, the pipe 121 is also referred to as the hot water outlet pipe 121. Thereby, the mixing valve 340 mixes the high-temperature water at the high-temperature side port connected to the high-temperature water pipe 119a and the low-temperature water at the low-temperature side port connected to the low-temperature water pipe 111, and outputs the mixture to the output port connected to the hot water outlet pipe 121. The high-temperature side port corresponds to the "first port", the low-temperature side port corresponds to the "second port", and the output port corresponds to the "third port".

[0046] The opening degree of the mixing valve 340 is controlled by the controller 20 using the stepping motor 341 as the drive source. By controlling the opening degree of the mixing valve 340, the flow state between the high-temperature side port (high-temperature water pipe 119a) and the low-temperature side port (low-temperature water pipe 111) and the output port (hot water pipe 121), that is, the mixing ratio of the high-temperature water and the low-temperature water is controlled. Specifically, the mixing valve 340 is controlled to any one of a fully closed state in which only the low-temperature side port communicates with the output port (0% high-temperature water), a fully open state in which only the high-temperature side port communicates with the output port (100% high-temperature water), and an intermediate opening degree in which both the low-temperature side port and the high-temperature side port communicate with the output port. The intermediate opening degree includes a plurality of opening degrees with different mixing ratios in a range where the ratio of the high-temperature water is greater than 0(%) and less than 100(%).

[0047] A temperature sensor 510 for detecting the temperature of the low-temperature water is arranged in the low-temperature water pipe 111. The temperature sensor 510 is arranged on the upstream side of the check valve 55 (the water supply end 101 side), that is, between the check valve 55 and the water supply end 101. In particular, by arranging the temperature sensor 510 upstream of the node Nx where the low-temperature water pipe 111 and the pipe 112 branch, the temperature of the low-temperature water introduced into the mixing valve 340 and the temperature of the low-temperature water introduced into the hot water storage tank 150 via the heat storage switching valve 330 (tank water inlet path) and the pipes 112, 113 can both be detected by one temperature sensor 510.

[0048] A temperature sensor 520 for detecting the hot water temperature is arranged in the hot water pipe 121 on the downstream side of the mixing valve 340. Further, in addition to the above-mentioned temperature sensor 555, a temperature sensor 530 is arranged in the high-temperature water pipe 119a. The temperature sensor 530 is arranged to detect the temperature of the high-temperature water input to the mixing valve 340.

[0049] The mixing ratio of the low-temperature water by the mixing valve 340 can be controlled based on the detected temperatures by the temperature sensors 510, 520, 530, for example. Thereby, the output temperature from the mixing valve 340 to the hot water pipe 121 (that is, the hot water temperature) can be controlled to the set temperature by the user.

[0050] Furthermore, it is preferable that a high-temperature avoidance solenoid valve 365 is arranged between the low-temperature water pipe 111 and the vicinity of the mixing valve 340 of the hot water outlet pipe 121. When the high-temperature avoidance solenoid valve 365 detects an over-high hot water outlet temperature detected by the temperature sensor 520, it is opened by the controller 20.

[0051] A flow sensor 430 and a flow control valve 370 are arranged in the hot water outlet pipe 121. The flow sensor 430 can detect the hot water outlet flow rate through the hot water outlet pipe 121. Also, according to the opening degree control by the controller 20 using the stepping motor 371 as a drive source, the flow control valve 370 can throttle the hot water outlet flow rate. For example, when the hot water outlet temperature does not rise, a significant decrease in the hot water outlet temperature can be suppressed by controlling the flow control valve 370. In addition, it is also possible to further arrange a temperature sensor 525 in the middle of the hot water outlet pipe 121 for control purposes of preventing freezing.

[0052] A pouring hot water pipe 301 leading to the connection end 109 branches from the hot water outlet pipe 121. A pouring hot water on-off valve 360 and a flow sensor 410 are arranged in the pouring hot water pipe 301. The pouring hot water on-off valve 360 is composed of a solenoid valve and is opened and closed according to a control command from the controller 20. By opening the pouring hot water on-off valve 360, the hot water controlled to the hot water supply set temperature output to the pipe 121 can be used for filling the bathtub 13 (Fig. 2). Furthermore, the amount of hot water supplied to the bathtub 13 can be calculated by integrating the detected values of the flow sensor 410.

[0053] A temperature sensor 580 and a pressure relief valve 390 are further arranged in the pipe 116. The pressure relief valve 390 can prevent the occurrence of overpressure in the circulation path of the high-temperature water from the auxiliary heat source machine 200.

[0054] Also, by opening the valve 110x provided at the connection end 110, the stored water in the hot water storage tank 150 can be forcibly discharged from the connection end 110 to the drain pipe 85 (Fig. 2).

[0055] In this way, the water heater 10 can perform a hot water supply operation including pouring hot water into the bathtub 13 by either hot water supply using the hot water accumulated in the hot water storage tank 150 (hereinafter also referred to as "tank hot water supply") or hot water supply using the hot water from the auxiliary heat source machine 200 during operation (hereinafter also referred to as "BU hot water supply"). That is, in the present embodiment, "hot water supply" includes both tank hot water supply and BU hot water supply. Further, by flowing hot water through the circulation path including the auxiliary heat source machine 200 and the heat exchangers 210 and 220, a heating operation and a post-combustion operation can be further performed.

[0056] The controller 20 can typically be constituted by a microcomputer. The controller 20 controls the operations of various devices based on the detection values of each sensor (temperature sensor, flow rate sensor, etc.) so that the water heater 10 operates according to the user instructions input to the remote controller 30, including controlling the opening degree of each valve having a stepping motor as a drive source and controlling the opening and closing of each on-off valve. The controller 20 corresponds to an embodiment of the "control device".

[0057] (Operation of the water heater) Next, with reference to FIG. 3, the operation of the water heater 10 according to the present embodiment will be described. In FIG. 3, a state in which at least one of the heating operation and the post-combustion operation is turned on is denoted as "heating / post-combustion on", while a state in which both the heating operation and the post-combustion operation are turned off is denoted as "heating / post-combustion off". As shown in FIG. 3, for each of the tank hot water supply and the BU hot water supply in the water heater 10, it is possible to set it to heating / post-combustion on or heating / post-combustion off.

[0058] Referring to FIG. 3, when the heating / supplementary firing of the tank water supply is off, the operation (combustion) of the auxiliary heat source unit 200 is turned off, the proportional valve 350 is fully closed, and the circulation pump 310 is also stopped. Further, the heat storage switching valve 330 is controlled to form a path from the tank water inlet path, that is, the path from pipe 112 to 113. In this state, when the faucet 15 connected to the hot water supply pipe 80 is opened, low-temperature water flows into the hot water storage tank 150 via pipes 112 and 113 due to the water supply pressure to the water supply end 101, and high-temperature water in the hot water storage tank 150 is output to pipe 130. The three-way valve 320 outputs high-temperature water from the hot water storage tank 150 regardless of whether it forms path P1 or P2.

[0059] The high-temperature water output to pipe 130 enters the mixing valve 340 from the high-temperature water pipe 119a via node Nc. Therefore, the tank water supply is executed by mixing the high-temperature water output from the hot water storage tank 150 and the low-temperature water in the low-temperature water pipe 111.

[0060] When the heating / supplementary firing is turned on during the tank water supply, the three-way valve 320 forms path P2 (circulation path), and the on-off valves 215 and / or 225 are opened. The heat storage switching valve 330 forms a tank water inlet path to output high-temperature water for hot water supply from the hot water storage tank 150 to pipe 130.

[0061] Furthermore, when the circulation pump 310 and the auxiliary heat source unit 200 operate, a high-temperature water circulation path including the auxiliary heat source unit 200, pipes 119, 119b, the primary sides of the heat exchangers 210 and / or 220, and pipes 114, 117 can be formed. The high-temperature water in the circulation path can heat the circulating water (heat medium) of the heating device 14a and the bathroom heating and drying machine 14b and / or the bathtub water flowing through the secondary sides of the heat exchangers 210 and / or 220.

[0062] During the hot water supply operation, if tank hot water supply cannot be performed due to a temperature drop in the hot water storage tank 150, BU hot water supply is executed. In BU hot water supply, the auxiliary heat source unit 200 operates. When heating / supplementary combustion is off, the heat storage switching valve 330 forms the tank water inlet path, and with the three-way valve 320 forming path P1, the circulation pump 310 operates.

[0063] As a result, the warm water in the hot water storage tank 150 is heated by the auxiliary heat source unit 200 via the circulation pump 310 from the pipe 132 and output to the pipe 119. At this time, by controlling the flow rate of the circulation pump 310, the pressure of the high-temperature water flowing through the high-temperature water pipe 119a (node Nc) via the proportional valve 350 is set higher than the fluid pressure output from the hot water storage tank 150 to the high-temperature water pipe 119a via the pipe 130. Thereby, while utilizing the preheating in the hot water storage tank 150, high-temperature water equivalent to that during tank hot water supply can be supplied from the high-temperature water pipe 119a to the high-temperature side of the mixing valve 340.

[0064] When heating / supplementary combustion is turned on during BU hot water supply, the on-off valves 215 and / or 225 are opened. Further, the three-way valve 320 forms path P2, and the heat storage switching valve 330 is controlled to form a circulation path, so that the low-temperature water introduced from the low-temperature water pipe 111 and the circulating high-temperature water flowing through the heat exchangers 210 and / or 220 are mixed and input from the circulation pump 310 to the auxiliary heat source unit 200. The high-temperature water output from the auxiliary heat source unit 200 is split into a path from the high-temperature water pipe 119a to the mixing valve 340 and a path from the pipe 119b to the heat exchangers 210, 220 at a ratio corresponding to the opening degree of the proportional valve 350. Therefore, when the opening degree of the proportional valve 350 increases, the supply ratio of the high-temperature water for hot water supply increases, while when the opening degree of the proportional valve 350 decreases, the supply ratio of the high-temperature water for heating / supplementary combustion increases.

[0065] Alternatively, even when the heating / reheating of the BU hot water supply is on, the heat storage switching valve 330 can also be set on the tank water inlet side, and by controlling the ratio of the paths P1 and P2 by the three-way valve 320, it is also possible to utilize the preheating of the hot water storage tank 150. However, in this case, since the flow rate ratio is variably controlled by both the three-way valve 320 and the proportional valve 350, there is a risk that the control will become complicated.

[0066] In the hot water supply device 10, in addition to the tank hot water supply using the high-temperature water in the hot water storage tank 150, BU hot water supply using the circulation pump 310 and the auxiliary heat source machine 200 is possible. In addition, even when the hot water supply operation is stopped, the proportional valve 350 is controlled to be fully closed, the three-way valve 320 is controlled to the path P2, and the circulation pump 310 is operated, so that by opening the on-off valves 215 and / or 225, a circulation path through which the high-temperature water heated by the auxiliary heat source machine 200 flows through the heat exchangers 210 and / or 220 can be formed.

[0067] As described above, in the hot water supply device 10 according to the present embodiment, when the hot water supply faucet 15 is opened, the mixing valve 340 mixes the high-temperature water in the high-temperature water pipe 119a and the low-temperature water in the low-temperature water pipe 111, so that hot water at an appropriate temperature is output to the hot water outlet pipe 121.

[0068] As described above, a check valve 55 is arranged in the low-temperature water pipe 111. When the check function of the check valve 55 is normal, the flow from the low-temperature side port of the mixing valve 340 toward the water supply end 101 is blocked. On the other hand, if an open failure occurs in the check valve 55 and the above check function is lost, there is a risk of reverse flow of high-temperature water from the high-temperature side port to the low-temperature side port of the mixing valve 340 during the hot water supply stop (when the hot water supply faucet 15 is closed). Specifically, when the pressure of the high-temperature side port of the mixing valve 340 is rising due to the operation of the circulation pump 310 or the like, if the mixing valve 340 is controlled to an opening degree for mixing high-temperature water and low-temperature water, there is a risk that the high-temperature water in the high-temperature water pipe 119a will flow backward into the low-temperature water pipe 111 through the low-temperature side port of the mixing valve 340.

[0069] For example, during the execution of the re-hot water standby control shown in FIG. 4, there is a concern that the above-mentioned reverse flow may occur.

[0070] FIG. 4 shows a flowchart for explaining the control process of the reheating standby control. The control process shown in FIG. 4 can be executed by the controller 20.

[0071] As shown in FIG. 4, the controller 20 detects the hot water supply end timing in step (hereinafter simply referred to as "S") 110. For example, based on the flow rate detection value by the flow rate sensor 430, it is periodically determined whether the hot water supply device 10 is in the hot water supply state or the hot water supply stop state, and when it changes from the hot water supply state in the previous cycle to the hot water supply stop state in this cycle, in this cycle, S110 is determined to be YES, and the hot water supply end timing is detected. In other cases, S110 is determined to be NO, and the processes after S120 are not started.

[0072] When the controller 20 detects the hot water supply end timing (when S110 is determined to be YES), in S120, until a predetermined time T1 elapses from the hot water supply end timing (when S120 is determined to be NO), in S130, the mixing valve 340 is set to a predetermined intermediate opening degree, and the proportional valve 350 is controlled to a predetermined opening degree that is not fully closed, thereby forming a reheating standby state.

[0073] In the reheating standby state, a path from the auxiliary heat source unit 200 to the high-temperature side port of the mixing valve 340 is formed by the proportional valve 350, and the mixing valve 340 is in a state where both the high-temperature side port and the low-temperature side port communicate with the hot water supply pipe 121. Therefore, when hot water supply is started by opening the hot water supply faucet 15 or the like, the high-temperature water remaining in the high-temperature water pipe 119a can be immediately used for hot water supply, and the high-temperature water from the auxiliary heat source unit 200 can also be quickly introduced into the mixing valve 340. As a result, when hot water supply resumes shortly after hot water supply stops, the hot water supply temperature can be quickly increased. Incidentally, if hot water supply starts during the processes of S120 to S130, the process of FIG. 4 is forcibly returned to S110, and the controller 20 monitors the next hot water supply end timing.

[0074] When a predetermined time T1 elapses without the hot water supply restarting (when the determination in S120 is YES), the controller 20 controls the proportional valve 350 to be fully closed and the mixing valve 340 to be fully closed (0% hot water) in S140.

[0075] Here, assume a case where a standby state for restarting hot water supply is formed by S130 during the heating operation or the supplementary heating operation. In this case, the high-temperature water output from the auxiliary heat source machine 200 via the proportional valve 350 is pressurized by the operation of the circulation pump 310 and reaches the high-temperature side port of the mixing valve 340. In this state, if an open failure occurs in the check valve 55 of the low-temperature water pipe 111, when the pressure of the high-temperature water introduced into the mixing valve 340 is greater than the water supply pressure from the water supply end 101, there is a risk of backflow of the high-temperature water through the high-temperature side port and the low-temperature side port of the mixing valve 340 into the low-temperature water pipe 111 and the pipe 112. And in the standby state for restarting hot water supply where such backflow occurs, since high-temperature water exists in both the high-temperature side port and the low-temperature side port of the mixing valve 340, when the hot water supply is started from this state, it is feared that the hot water supply temperature immediately after the start of the hot water supply will rise more than expected.

[0076] (Detection of open failure of check valve) Therefore, in the hot water supply device according to the present embodiment, in order to avoid the above-described problems in hot water supply temperature control, a function for detecting an open failure of the check valve 55 is provided.

[0077] In FIGS. 5 to 7, a flowchart for explaining the failure diagnosis process of the check valve in the hot water supply device according to the present embodiment is shown. The control process shown in FIGS. 5 to 7 can be executed by the controller 20.

[0078] The controller 20 executes a failure diagnosis by S220 to S240 during the hot water supply stop (when the determination in S210 is YES). On the other hand, during the hot water supply (when the determination in S210 is NO), the failure diagnosis is not executed. The determination of whether it is during the hot water supply or during the hot water supply stop in S210 can be executed based on the detection value by the flow rate sensor 430 as described above.

[0079] In S220, the controller 20 compares the detected temperature Tw of the temperature sensor 510 with the reference temperature Tref. When Tw > Tref (when the determination in S220 is YES), a release failure of the check valve 55 is detected by S230. On the other hand, when Tw ≤ Tref (when the determination in S220 is NO), it is determined by S240 that there is no detection of a release failure of the check valve 55.

[0080] The reference temperature Tref is set according to the temperature of the low-temperature water introduced into the water supply end 101 so that the backflow of high-temperature water to the upstream side (water supply end 101 side) of the check valve 55 can be detected. Specifically, it is necessary to set it between the incoming water temperature from the water supply end 101 and the temperature of the high-temperature water. It is assumed that the incoming water temperature varies depending on the ambient temperature of the water heater 10 (water supply end 101). Therefore, the reference temperature Tref can be variably set inside the controller 20 by inputting the detected temperature by a detector (not shown) of the ambient temperature to the controller 20. Alternatively, it is also possible to receive an input of the reference temperature Tref from outside the controller 20 (for example, a server connected to the controller 20).

[0081] Also, as shown in FIG. 6, the reference temperature Tref can be set using the temperature history during hot water supply.

[0082] Referring to FIG. 6, the controller 20 detects the hot water supply start timing by S250. For example, contrary to S110 (FIG. 4), when it changes from being in a hot water supply stop state in the previous cycle to being in a hot water supply state in this cycle, in this cycle, S250 is determined to be YES and the hot water supply start timing is detected. In other cases, S250 is determined to be NO and the processing after S260 is not started.

[0083] When the hot water supply start timing is detected (YES determination in S250), the controller 20 sets a reference temperature Tref based on the average value TW0 of the detected temperatures Tw obtained by acquiring the detected temperature Tw of the temperature sensor 510 for a certain period when a predetermined time Td has elapsed since the hot water supply start timing (YES determination in S260). For example, the reference temperature Tref can be calculated by adding a predetermined margin value α to the average value (Tref = TW0 + α). On the other hand, until a predetermined time Td has elapsed since the hot water supply start timing (NO determination in S260), the process of S270 is put on standby.

[0084] In this way, when S210 in FIG. 5 is determined to be YES, the reference temperature Tref used in S220 can be set using the actual value of the detected temperature Tw of the temperature sensor 510 in the previous hot water supply operation. Thereby, the detection accuracy of the opening failure of the check valve 55 can be improved.

[0085] Alternatively, in order to suppress false detection of the opening failure, it is also possible to limit the opportunity for failure diagnosis by S220 to S240 in FIG. 5.

[0086] FIG. 7 shows the control process added to limit the execution opportunity of the failure diagnosis.

[0087] As shown in FIG. 7, when the determination in S210 is YES, that is, during the hot water supply stop, the controller 20 executes an additional determination of S215 including S215a and S215b.

[0088] In S215a, the controller 20 determines whether the auxiliary heat source machine 20 is in the combustion operation (during BU combustion) and whether the circulation pump 310 is operating. Further, in S215b, the controller 20 determines whether the mixing valve 340 is at an intermediate opening degree. Note that in S215b, it may be determined whether the hot water supply device 10 is in the re-hot water supply standby state (S130).

[0089] When the controller 20 is in the hot water supply stop state (when the determination in S210 is YES), if both S215a and S215b are determined to be YES, the process proceeds to S220 (Fig. 5), and a failure diagnosis using the detected temperature Tw (temperature sensor 510) is executed. On the other hand, if at least one of S215a and S215b is determined to be NO, the process proceeds to S240, and no open failure of the check valve 55 is detected.

[0090] That is, by the additional determination in Fig. 7, the failure diagnosis by S220 is executed while restricting to the internal state where the high-temperature side port and the low-temperature side port of the mixing valve 340 communicate with each other and high-temperature water (BU combustion) pressurized to the high-temperature side port of the mixing valve 340 is input. As a result, the failure detection corresponding to the rise in the detected temperature Tw due to the backflow is executed only when the backflow of high-temperature water is likely to occur in the internal state where an open failure occurs in the check valve 55. This can prevent the open failure of the check valve 55 from being erroneously detected due to the influence of noise in the output value of the temperature sensor 510 or the like.

[0091] In this way, by the controller 20 executing the control processes shown in Figs. 5 to 7, one embodiment of the "failure diagnosis unit" can be configured.

[0092] (Control at the time of detecting an open failure of the check valve) Next, the control for dealing with the open failure of the check valve 55 detected by the control processes described with reference to Figs. 5 to 7 will be described with reference to Figs. 8 and 9. This control is for avoiding high-temperature hot water discharge by starting hot water supply from the state where high-temperature water exists in both the high-temperature side port and the low-temperature side port of the mixing valve 340 described above. The control processes shown in Figs. 8 and 9 can also be executed by the controller 20.

[0093] According to the first control example shown in Fig. 8, the controller 20 determines, at S310, whether an open failure of the check valve 55 has been detected. That is, S310 is determined to be YES in conjunction with S230 in Fig. 5.

[0094] When the controller 20 detects an opening failure of the check valve 55 (when the determination at S310 is YES), it outputs a message notifying that a failure (opening failure) of the check valve 55 has occurred and a request for repair arrangements. The notification message can be output in a manner recognizable to the user visually or aurally, for example, using the display unit 31 and / or the speaker 34 of the remote controller 30. When no opening failure of the check valve 55 is detected (when the determination at S310 is NO), the processing after S320 is not executed.

[0095] Furthermore, at S330, the controller 20 controls the mixing valve 340 to be fully closed (hot water 0(%)) in response to the error state of the check valve 55. That is, the hot water temperature control is not executed, and the mixing valve 340 is controlled to be fully closed. Also, when the check valve 55 is in an error state, the low-temperature water pipe 111 may also be at a high temperature. Therefore, in order to avoid the hot water tap 15 being opened to discharge high-temperature hot water, the flow rate adjustment valve 370 is further controlled to be fully closed. Thereby, high-temperature hot water discharge during an opening failure of the check valve 55 is avoided.

[0096] At S340, the controller 20 maintains the full-closed control of the mixing valve 340 by S330 until the error state of the check valve 55 is released (when the determination at S340 is NO). For example, the error state is released in response to an operation input by the service technician when the replacement work of the failed check valve 55 is completed.

[0097] When the error code is released (when the determination at S340 is YES), the controller 20 releases the full-closed control of the mixing valve 340 and the flow rate adjustment valve 370. Thereafter, the opening control of the mixing valve 340 by the hot water temperature control or the like, that is, the control of the mixing ratio of the hot water and the low-temperature water, is resumed, and the hot water can be discharged through the flow of the hot water pipe 121.

[0098] According to the first control example of FIG. 8, when a release failure of the check valve 55 is detected, by controlling the mixing valve 340 to be fully closed, the path from the hot water pipe 119a to the hot water supply pipe 121 is blocked, and continuous hot water discharge at a high temperature can be avoided. In this way, by the controller 20 executing the control process shown in FIG. 8, an embodiment of the "fault response control unit" can be configured.

[0099] In the second control example shown in FIG. 9, after S310 and S320 similar to those in FIG. 7, the controller 20 calculates, by S400, the increase amount (temperature increase amount) Twup of the detected temperature Tw of the temperature sensor 510 with respect to the reference temperature Tref (Twup = Tw - Tref). In the second control example of FIG. 9, actions for the release failure are executed step by step according to the temperature increase amount Twup.

[0100] When the temperature increase amount Twup is lower than a predetermined determination value Tr (when the determination in S410 is YES), the controller 20 controls the proportional valve 350 to be fully closed by S420 to block the supply of high-temperature water from the auxiliary heat source machine 200 to the mixing valve 340. On the other hand, the mixing valve 340 is not controlled to be fully closed, and the opening degree control is continued. Further, different from S330, the flow rate adjustment valve 370 is not controlled to be fully closed in order to allow the flow through the hot water supply pipe 121. Thereby, the tank hot water supply using the high-temperature water stored in the hot water storage tank 150 can be continued.

[0101] Normally, the temperature of the high-temperature water stored in the hot water storage tank 150 is lower than the temperature of the high-temperature water output from the auxiliary heat source machine 200. Therefore, in a range where the temperature increase amount Twup is small, it is expected that the increase amount of the hot water supply temperature is also small, so the continuation of the tank hot water supply is allowed. For example, based on the detected temperatures (temperature sensors 151 to 156) of the hot water stored in the hot water storage tank 150, it is possible to determine whether the tank hot water supply can be continued.

[0102] Similar to the error recovery in S340 of FIG. 8 (when YES is determined in S430), the process proceeds to S440, and the control to fully close the proportional valve 350 in S420 is released. On the other hand, until the error is recovered (when NO is determined in S430), the process returns to S400. That is, after detecting the opening failure of the check valve 55, when the temperature rise amount is small (Twup < Tr), S420 is continuously executed, and tank water supply is permitted.

[0103] On the other hand, after detecting the opening failure of the check valve 55, when the temperature rise amount Twup is equal to or greater than the determination value Tr (when NO is determined in S410), the controller 20 executes S330 to S350 similar to those in FIG. 8. Thereby, when the opening failure of the check valve 55 is detected and the temperature rise amount Twup due to backflow is large, the same control as in FIG. 8 to fully close the mixing valve 340 and the flow rate adjustment valve 370 is executed.

[0104] In the second control example of FIG. 9, even if an opening failure occurs in the check valve 55, the user convenience can be improved by continuing the tank operation within a range where the temperature rise amount Twup is small. In FIG. 9, when YES is determined in S410, the process of S420 is executed, thereby realizing an embodiment of the "first failure response control unit", and when NO is determined in S410, the process of S330 is executed, thereby realizing an embodiment of the "second failure response control unit".

[0105] Also, while the circulation pump 310 and the auxiliary heat source unit 200 are operating during the hot water supply stop of the hot water supply device 10 shown in FIG. 1, and the mixing valve 340 is controlled to an opening degree (intermediate opening degree) that allows hot and cold water to flow between both the high-temperature side port and the low-temperature side port (first and second ports) and the output port (third port), there may be a case where a hot and cold water circulation path is formed from the low-temperature water pipe 111 via the pipe 112 when an opening failure of the check valve 55 occurs. In order to detect the opening failure of the check valve 55 in this case, the arrangement position of the temperature sensor 510 is preferably upstream of the check valve 55 and included in the above-described hot and cold water circulation path from the low-temperature water pipe 111 via the pipe 112. However, even when the temperature sensor 510 is not arranged on the hot and cold water circulation path, it can be used to detect the opening failure of the check valve 55 by arranging it in the vicinity of the node Nx as exemplified in the present embodiment.

[0106] Further, in the present embodiment, the detection of the check valve failure has been described by exemplifying a hot water storage supply device equipped with a hot water storage tank, but the configuration of the hot water supply device 10 is not limited to the example of FIG. 1. That is, similar to the present embodiment, the detection of the opening failure of the check valve according to the present embodiment can be applied to a hot water supply device having a configuration including a mixing valve for hot and cold water and a check valve arranged in the water inlet path to the low-temperature water side port of the mixing valve.

[0107] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0108] 10 Water supply device, 13 Bathtub, 14a Heating device, 14b Bathroom heating and drying machine, 15 Water supply faucet, 20 Controller, 25 Housing, 30 Remote control, 31 Display unit, 32 Operation switch, 33 Operation unit, 34 Speaker, 55, 56, 322 Check valve, 80 Water supply pipe, 81 Water supply pipe, 82 Fuel gas pipe, 85 Drain pipe, 101 Water supply end, 102 Hot water outlet end, 103 - 110 Connection end, 111 Low-temperature water pipe, 119a High-temperature water pipe, 121 Hot water supply pipe, 150 Hot water storage tank, 151 - 156, 510, 520, 525, 530, 550, 555, 560, 580, 590 Temperature sensor, 200 Auxiliary heat source machine, 201a Input end, 201b Output end, 210, 220 Heat exchanger, 215, 225 On-off valve, 230 Heating tank, 240 Heating pump, 301 Pouring pipe, 310, 315 Circulation pump, 311a Suction port, 311b Discharge port, 320 Three-way valve, 321, 341, 351, 371, 381 Stepping motor, 330 Heat storage switching valve, 340 Mixing valve, 350 Proportional valve, 360 Pouring on-off valve, 365 High-temperature avoidance solenoid valve, 370 Flow rate adjustment valve, 380 Hot water storage switching valve, 390 Pressure relief valve, 410, 420, 430 Flow rate sensor, Nb, Nc, Nx Node, Tref Reference temperature, Tw Detected temperature, Twup Temperature rise amount.

Claims

Claim 1: A water supply device, a high-temperature water pipe for supplying high-temperature water, a low-temperature water pipe for supplying low-temperature water from a water supply end, a hot water pipe connected to a hot water outlet end, a mixing valve having a first port connected to the high-temperature water pipe, a second port connected to the low-temperature water pipe, and a third port connected to the hot water pipe, a control device for controlling a mixing ratio of the hot water flowing from the first port to the third port and the hot water flowing from the second port to the third port according to an opening degree of the mixing valve, a check valve having a check function, which is inserted and connected to the low-temperature water pipe to block the flow from the second port to the water supply end, and a temperature detector disposed in a path of the low-temperature water between the water supply end and the check valve. The control device includes a failure diagnosis unit that detects an open failure in which the check function of the check valve is lost when a detected temperature by the temperature detector rises above a reference temperature set according to a temperature of the low-temperature water introduced into the water supply end. The failure diagnosis unit sets the reference temperature according to the detected temperature of the temperature detector during water supply of the water supply device, and when the detected temperature by the temperature detector rises above the reference temperature set from the detected temperature during the previous water supply while the water supply device is stopped from supplying water, the open failure of the check valve is detected. A water supply device. Claim 2 The water supply device further includes a circulation pump, a circulation path of the high-temperature water formed according to an operation of the circulation pump, a heat source machine included in the circulation path, and a proportional valve connected between the circulation path and the high-temperature water pipe. When the hot water supply of the hot water supply device is stopped, if the circulation pump and the heat source machine are operating, and the mixing valve is controlled to an opening degree where both the first and second ports communicate with the third port, when the detected temperature by the temperature detector rises above the reference temperature, the hot water supply device according to claim 1 detects the open failure of the check valve.

3. The high-temperature water in the circulation path is used for heating the heat medium supplied to the heating equipment connected to the hot water supply device. The hot water supply device according to claim 2.

4. Further comprising a flow control valve interposed in the hot water outlet pipe, The control device, When the open failure of the check valve is detected, while blocking the flow between the first port and the third port, the opening degree of the mixing valve is controlled so that the second port and the third port communicate with each other, and a failure response control unit for controlling the flow control valve to be fully closed. The hot water supply device according to any one of claims 1 to 3.

5. A circulation pump, A circulation path of high-temperature water formed in response to the operation of the circulation pump, A heat source machine included in the circulation path, A proportional valve connected between the circulation path and the high-temperature water pipe, A flow control valve interposed in the hot water outlet pipe, Further comprising a hot water storage tank, The output end of the hot water storage tank is connected to the high-temperature water pipe on the first port side of the mixing valve with respect to the proportional valve, The control device, When the open failure of the check valve is detected, when the increase amount of the detected temperature by the temperature detector with respect to the reference temperature is lower than a predetermined determination value, while controlling the opening degree of the proportional valve to block the path between the circulation path and the high-temperature water pipe, the opening degree of the mixing valve is controlled according to the hot water outlet temperature in the hot water outlet pipe, and a first failure response control unit for controlling the flow control valve to be fully closed. When the opening failure of the check valve is detected and the amount of increase is equal to or greater than the determination value, the flow between the first port and the third port is blocked while the second port and the third port allow fluid flow. A second failure response control unit is provided to control the opening degree of the mixing valve and to control the flow rate adjustment valve to allow fluid flow through the hot water supply pipe. The hot water supply device according to claim 1, further comprising:

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