Hot water supply system

Abstract

To provide a hot water system which can improve durability of a water supply valve while preventing water shortage in a water supply tank, in a structure where the water supply valve is provided in a water supply passage for supplying water of a water supply source to the water supply tank.SOLUTION: A hot water system A includes: a heating heat source 500; a hot water storage tank 6 for storing hot water heated in the heating heat source; a water supply tank 2 for storing water of the water supply source; a pump 37 for allowing a hot water tapping terminal 400 to supply hot water in the hot water storage tank and the water in the water supply tank; a water supply passage for supplying the water of the water supply source to the water supply tank; a water supply valve for opening / closing the water supply passage; and a control device C. Flow rate detection means 36 is provided which detects a used flow rate at the hot water tapping terminal. The plurality of water supply passages (water supply pipes 11, 12) is provided. The water supply valves (water supply valves 15, 16) are provided at the plurality of water supply passages respectively. The control device C performs control for changing the number of water supply valves whose valves are opened according to the used flow rate at the hot water tapping terminal, at the time of a water supply operation to the water supply tank 2 by the water supply passage.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a hot water supply system that includes a hot water storage tank, a water supply tank, a pump, etc., and supplies hot and cold water to hot water outlets such as showers and faucets.

Background Art

[0002] Conventionally, in a hot water supply system, in order to be able to supply sufficient hot and cold water even when multiple hot water outlets such as showers and faucets are used for hot water supply simultaneously, a heating heat source, a hot water storage tank for storing hot water heated by the heating heat source, a water supply tank for storing water from a water supply source, a pump for supplying water from the water supply tank or hot water from the hot water storage tank to the hot water outlet, a water supply pipe for supplying water from the water supply source to the water supply tank, and a water supply valve for opening and closing the water passage of the water supply pipe are provided (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above hot water supply system, when it is assumed that the flow rate used at a hot water outlet such as a shower increases and the outflow flow rate of water from the water supply tank increases, in order to prevent the water supply tank from running out of water, it is conceivable to increase the water supply pipe for supplying water to the water supply tank to increase the water supply flow rate to the water supply tank. In this case, when performing the water supply operation to the water supply tank, if the outflow flow rate from the water supply tank, that is, the flow rate used at the hot water outlet is small, the water supply flow rate to the water supply tank will increase. As a result, the difference between the water supply flow rate and the use flow rate becomes large, and the water level fluctuation in the water supply tank may become large. As a result, the water supply valve may frequently perform opening and closing operations, resulting in a problem of reducing the durability of the water supply valve.

[0005] The present invention has been made in view of the above circumstances, and in a configuration in which a water supply valve is provided in a water supply path for supplying water from a water supply source to a water supply tank, it is possible to improve the durability of the water supply valve while preventing the water supply tank from running dry, and an object thereof is to provide a hot water supply system.

Means for Solving the Problems

[0006] The hot water supply system according to the present invention includes a heating heat source, a hot water storage tank for storing hot water heated by the heating heat source, a water supply tank for storing water from a water supply source, a pump for supplying the hot water in the hot water storage tank and the water in the water supply tank to a hot water outlet terminal, a water supply path for supplying water from the water supply source to the water supply tank, a water supply valve for opening and closing the water supply path, and a control device, a plurality of the water supply paths are provided, the water supply valve is provided in each of the plurality of water supply paths, flow rate detection means for detecting the flow rate used at the hot water outlet terminal is provided, the control device is configured to perform control to change the number of water supply valves to be opened according to the flow rate used at the hot water outlet terminal during the water supply operation to the water supply tank by the water supply path.

[0007] According to the above configuration, when performing the water supply operation to the water supply tank, by changing the number of water supply valves to be opened according to the flow rate used at the hot water outlet terminal, the difference between the water supply flow rate to the water supply tank and the flow rate used at the hot water outlet terminal can be reduced, and the water level fluctuation in the water supply tank can be reduced. Therefore, the number of times of opening and closing of each water supply valve can be reduced. In addition, since a plurality of water supply paths provided with water supply valves are provided, when the flow rate used at the hot water outlet terminal is large, the number of water supply valves to be opened can be increased, so that a larger water supply flow rate can be ensured for the water supply tank. Therefore, even when the flow rate used at the hot water outlet terminal is large, it is possible to prevent the water supply tank from running dry and improve the durability of the water supply valve.

[0008] In the hot water supply system, The control device can be configured to store the water supply valve that was opened immediately before, and when opening the water supply valve next time, perform control to open the valve from a water supply valve different from the stored water supply valve.

[0009] According to the above configuration, when performing the water supply operation to the water supply tank, since the water supply valve to be opened can be changed each time, the bias of the water supply valve to be used is suppressed, and the durability of the water supply valve can be further improved.

[0010] In the above water heating system, it is provided with Lo water level detection means for detecting that the water level of the water supply tank has become lower than a predetermined Lo water level. When performing the water supply operation to the water supply tank, the control device can be configured to perform control to open a plurality of water supply valves even if the usage flow rate at the hot water outlet terminal is less than a predetermined amount when the Lo water level detection means detects that the water level is lower than the Lo water level.

[0011] When the Lo water level detection means detects that the water level is lower than the Lo water level, it means that the water storage amount in the water supply tank is small, and it can be said that the water supply tank is approaching a state of running out of water. According to the configuration of the present invention, when the Lo water level detection means detects that the water level is lower than the Lo water level, even if the usage flow rate at the hot water outlet terminal is less than a predetermined amount, by opening a plurality of water supply valves, the water supply flow rate to the water supply tank can be increased, and the water supply tank can be reliably prevented from running out of water. Note that the detection of the water level lower than the Lo water level also includes the case where the detection has been performed for a predetermined time.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiment for Carrying Out the Invention

[0013] Hereinafter, a hot water supply system according to an embodiment of the present invention will be described. The hot water supply system A of the embodiment shown in FIG. 1 is, for example, a hot water supply system that can be used in commercial facilities such as beauty salons. It includes a hot water supply pressurization tank unit 1, a heat source unit 500, and a control device C, and is configured to be able to supply a large amount of water or hot water to a plurality of hot water outlet terminals 400 such as showers and faucets that serve as hot water taps from the hot water supply pressurization tank unit 1. The heat source unit 500 has a first gas heat source machine 501 and a second gas heat source machine 502 that are heating heat sources. Note that as the heating heat source, one or three or more gas heat source machines may be provided, or a heat pump, an electric heater, or the like may be used instead of the gas heat source machine. The hot water supply pressurization tank unit 1 includes a water supply tank 2 that stores water supplied from a water supply source, and a hot water storage tank 6 that stores hot water heated by the heat source unit 500, and is capable of supplying a large amount of hot water to the hot water outlet terminal 400. In addition, an outside air temperature sensor 80 for detecting the outside air temperature is provided at the bottom of the housing of the hot water supply pressurization tank unit 1.

[0014] The first and second gas heat source machines 501 and 502 are gas water heaters. Although not shown, they include a gas burner, a heat exchanger, a heat source machine control device for controlling the operation of the heating heat source, and the like inside the housing. The first and second gas heat source machines 501 and 502 and the hot water storage tank 6 are connected by a heating circulation circuit including a heating forward pipe 40 that sends hot water from the hot water storage tank 6 and water from the water supply tank 2 to the first and second gas heat source machines 501 and 502, and a heating return pipe 44 that returns the hot water heated by the first and second gas heat source machines 501 and 502 to the hot water storage tank 6.

[0015] The heating forward pipe 40 has one end connected to the lower part of the hot water storage tank 6 and the other end branched into a first heating forward pipe 41 and a second heating forward pipe 42 midway so as to be connected to the first gas heat source machine 501 and the second gas heat source machine 502. The heating return pipe 44 has one end where a first heating return pipe 45 and a second heating return pipe 46 connected to each gas heat source machine 501, 502 merge midway and the other end connected to the upper part of the hot water storage tank 6.

[0016] An automatic air vent valve 57 that opens when the pressure in the hot water storage tank 6 rises above a predetermined value and a heating return temperature sensor 58 that detects the temperature of the hot water flowing into the hot water storage tank 6 are installed in the heating return pipe 44. Further, the heating forward pipe 40 merges with the water supply forward pipe 3, and a tank bottom temperature sensor 55 that detects the temperature of the hot water supplied from the hot water storage tank 6 to the heating forward pipe 40 and a manually openable and closable valve 56 (it may also be a valve whose opening and closing are controlled by the control device C.) are installed upstream of the merging part with the water supply forward pipe 3. A heating forward temperature sensor 50 is installed in the heating forward pipe 40 downstream of the merging part with the water supply forward pipe 3 and upstream of the branching part of the first and second heating forward pipes 41, 42. A first heating circulation pump 51 and a second heating circulation pump 52 are installed in the first and second heating forward pipes 41, 42 respectively, and check valves 53, 54 are installed downstream of the first and second heating circulation pumps 51, 52. By operating the first and second heating circulation pumps 51, 52 and operating the first and second gas heat source machines 501, 502, hot water at a predetermined hot water outlet temperature heated by the first and second gas heat source machines 501, 502 is supplied to the hot water storage tank 6.

[0017] The hot water storage tank 6 is a tank made of a metal (e.g., stainless steel) with excellent corrosion resistance. Although not shown, the outer periphery is covered with a heat insulating material. The capacity of the hot water storage tank 6 in this embodiment is, for example, 50 liters. At the lower part of the hot water storage tank 6, a heating supply pipe 40 and a hot water return pipe 72 for returning the hot water from the hot water outlet terminal 400 are connected. At the upper part of the hot water storage tank 6, a heating return pipe 44 and a hot water supply pipe 71 connected to the hot water outlet terminal 400 are connected. In the hot water storage tank 6, a first hot water temperature sensor 61, a second hot water temperature sensor 62, and a third hot water temperature sensor 63 for detecting the temperature of the hot water stored inside are attached at predetermined intervals in order from above.

[0018] The water supply tank 2 is disposed above the hot water storage tank 6 and supplies water to the hot water outlet terminal 400, the hot water storage tank 6, the gas heat source machines 501, 502, etc. The capacity of the water supply tank 2 in this embodiment is, for example, 70 liters. Although not shown, a part of the water supply tank 2 is open to the atmosphere. At the upper part of the water supply tank 2, two first water supply pipes 11 and second water supply pipes 12 (a plurality of water supply paths) branched from a water supply pipe 10 for supplying city water as a water supply source to the water supply tank 2 are connected. At the lower part of the water supply tank 2, a water supply forward pipe 3 is connected. In FIGS. 1 and 2, for the sake of explanation, the first and second water supply pipes 11, 12 are described as being arranged vertically with respect to the water supply tank 2, but actually they are arranged at the same height at the upper part of the water supply tank 2. In the first and second water supply pipes 11, 12, a first governor 13 and a second governor 14, and a first water supply valve 15 and a second water supply valve 16 are interposed in order from the upstream side. The first and second water supply valves 15, 16 are constituted by electromagnetic valves that serve as on-off valves. The first and second water supply valves 15, 16 are connected to the control device C and are controlled to open and close by a control signal from the control device C. In this way, by connecting a plurality of water supply pipes (the first and second water supply pipes 11, 12) to the water supply tank 2, the pressure loss can be reduced and the water supply tank 2 can be supplied with water in a short time. Note that the first and second water supply pipes 11, 12 may be constituted by a plurality of water supply pipes drawn in parallel from the water supply source, in addition to being constituted by branching from the water supply pipe 10.

[0019] The water supply tank 2 has a drain port 21 on one side wall below the connection ports of the first and second water supply pipes 11 and 12 and above the connection port of the water supply pipe 3 in the water supply direction. An overflow pipe 9 is connected to the side of the drain port 21 inside the water supply tank 2. A drain pipe 200 is connected to the outside of the drain port 21 of the water supply tank 2 (see Fig. 1). On the other side wall of the water supply tank 2, an overflow float sensor 22, a Hi float sensor 23, a Lo float sensor 24, and a low water level float sensor 25 are arranged at predetermined intervals as water level detection means for detecting the water level in the water supply tank 2 from above in sequence.

[0020] The overflow pipe 9 is a tubular member for draining excess water in the water supply tank 2 when the water level in the water supply tank 2 exceeds a predetermined height, and is installed in the water supply tank 2 (see Figs. 1 and 2). One end of the overflow pipe 9 is an upstream end opening 91 communicating with the inside of the water supply tank 2, and the other end is connected to the drain port 21 of the water supply tank 2. The overflow pipe 9 is provided with an overflow hole 92 communicating with the inside of the water supply tank 2 at the upper part near the upstream end opening 91. Therefore, the excess water in the water supply tank 2 flows into the overflow pipe 9 through the overflow hole 92 and the upstream end opening 91 and is discharged to the outside. The diameter of the upstream end opening 91 is set so that the amount of water flowing in from the upstream end opening 91 is larger than the maximum water supply flow rate from the first and second water supply pipes 11 and 12. Also, the diameter of the overflow hole 92 is set so that the amount of water flowing in from the overflow hole 92 is smaller than the amount of water flowing in from the upstream end opening 91. Further, the overflow pipe 9 is formed in a substantially U shape, and the entire lower curved portion constitutes a trap portion 93 for storing and sealing a part of the drained water. The trap portion 93 prevents the intrusion of odors, various bacteria, etc. from the downstream side. Note that the overflow pipe 9 may be installed outside the water supply tank 2. In this case, the portion on the upstream end opening 91 side may be bent in an L shape and connected to the drain port 21 from the outside of the water supply tank 2, and a straight connecting pipe may be horizontally connected so that the overflow hole (92) communicates with the inside of the water supply tank 2 at the height position of the overflow hole (92).

[0021] When the water level in the water supply tank 2 rises to a height that submerges the float built into the sensor for each of the float sensors 22 to 25, the float moves and turns ON. When the water level in the water supply tank 2 drops and the float is no longer submerged, the float moves in the opposite direction due to the drop in the water surface and turns OFF. That is, each of the float sensors 22 to 25 detects that the water level (water storage volume) in the water supply tank 2 has reached the water level at the sensor position when it turns ON, and detects that the water level (water storage volume) of the water supply tank 2 has fallen below the water level at the sensor position when it turns OFF. The low water level detected by the low water level float sensor 25 is set, for example, at the 15-liter position of the water storage volume of the water supply tank 2. The Lo water level detected by the Lo float sensor 24 is set, for example, at the 45-liter position of the water storage volume of the water supply tank 2. The Hi water level detected by the Hi float sensor 23 is set, for example, at the 60-liter position of the water storage volume of the water supply tank 2. The overflow water level detected by the overflow float sensor 22 is set, for example, at the 64-liter position of the water storage volume of the water supply tank 2.

[0022] Regarding the height position relationship between each of the float sensors 22 to 25 in the water supply tank 2 and the overflow pipe 9, the low water level float sensor 25 is arranged corresponding to a height position below the overflow pipe 9, the Lo float sensor 24 is arranged corresponding to a height position slightly above the trap portion 93 at the lower part of the overflow pipe 9, the Hi float sensor 23 is arranged corresponding to a height position slightly above the overflow hole 92 in the vicinity of the overflow hole 92, and the overflow float sensor 22 is arranged corresponding to a height position slightly below the upstream end opening 91 in the vicinity of the upstream end opening 91. The detection signals of the water levels detected by each of the float sensors 22 to 25 are output to the control device C. Note that the means for detecting the water level of the water supply tank 2 is not limited to the float sensors 22 to 25, and other contact type water level gauges such as capacitive type or non-contact type water level gauges such as ultrasonic type may be used.

[0023] The water supply pipe 3 branches into a first water supply pipe 31 and a second water supply pipe 32 on the upstream side so that water flows in parallel. A water supply pressure pump 37 is provided upstream of the branch between the first water supply pipe 31 and the second water supply pipe 32. This water supply pressure pump 37 constitutes a pump that supplies the hot water stored in the hot water storage tank 6 and the water stored in the water supply tank 2 to the hot water outlet terminal 400.

[0024] A check valve 33 and a pressure sensor 35 for detecting water pressure are provided in the first water supply pipe 31 in order from the upstream side. A check valve 34 and a water volume sensor (flow rate detection means) 36 for detecting the flow rate of water are provided in the second water supply pipe 32 in order from the upstream side. Note that, instead of providing parallel water paths such as the first and second water supply pipes 31 and 32, the pressure sensor and the water volume sensor can also be provided in a single water path. However, by forming a parallel water path with the first water supply pipe 31 and the second water supply pipe 32 so that water flows in parallel and providing a pressure sensor and a water volume sensor in each water path, the pressure loss in the water supply pipe 3 can be reduced. Although the water flow rate in each water path of the first and second water supply pipes 31 and 32 can be different, if the ratio of the pressure loss is known, the total water flow rate of the water supply pipe 3 can be calculated from the water flow rate detected by the water volume sensor 36. The detection signal of the detected pressure detected by the pressure sensor 35 and the detection signal of the detected flow rate detected by the water volume sensor 36 are output to the control device C.

[0025] The first water supply pipe 31 and the second water supply pipe 32 merge at a confluence downstream of the pressure sensor 35 and the water volume sensor 36, and the other end of the water supply pipe 3 is connected to a confluence with a heating pipe 40 connected to the lower part of the hot water storage tank 6. Further, the water supply pipe 3 branches into a water supply branch pipe 38 connected to the hot water outlet terminal 400 downstream of the confluence of the first and second water supply pipes 31 and 32. The downstream side of the water supply branch pipe 38 branches into a plurality according to the number of showers or faucets of the hot water outlet terminal 400. A check valve 39 is provided in the water supply pipe 3 downstream of the branch of the water supply branch pipe 38. The water supply pipe 3 including the first and second water supply pipes 31 and 32 and the water supply branch pipe 38 constitutes a water supply circuit.

[0026] One end of the hot water return pipe 72, which is connected to the lower part of the hot water storage tank 6, is connected to the hot water supply pipe 71 at the hot water outlet terminal 400 at the other end. An instantaneous hot water circulation pump 73 is installed in the hot water return pipe 72, and an instantaneous hot water return temperature sensor 74 and a check valve 75 are installed on the downstream side of the instantaneous hot water circulation pump 73. The hot water supply pipe 71 and the hot water return pipe 72 arranged between the hot water storage tank 6 and the hot water outlet terminal 400 constitute an instantaneous hot water circulation circuit.

[0027] In this hot water supply system A, the flow rate of the hot water used at the hot water outlet terminal 400 is equal to the outflow flow rate of the water supply tank 2 flowing out into the water supply pipe 3, which is the detected flow rate by the water flow sensor 36. That is, the flow rate used at the hot water outlet terminal 400 is the total flow rate of the water flowing through the water supply pipe 3 that is branched at the branch part and supplied from the water supply branch pipe 38, and the amount of hot water flowing out from the hot water storage tank 6 due to the inflow from the water supply pipe 3 and supplied through the hot water supply pipe 71. Originally, it is the flow rate of the water flowing out from the water supply tank 2 and flowing through the water supply pipe 3. The flow rate of the water flowing through the water supply pipe 3 is detected by the water flow sensor 36. Therefore, the flow rate used at the hot water outlet terminal 400 is also the outflow flow rate of the water supply tank 2 and becomes the detected flow rate of the water flow sensor 36. Note that the detection of the flow rate used at the hot water outlet terminal 400 is not limited to the water flow sensor 36. For example, it may be detected by water flow sensors provided respectively in the water supply branch pipe 38 and the hot water supply pipe 71, or may be detected by a water flow sensor provided at the hot water outlet terminal 400.

[0028] The hot water supply system A includes a remote controller R for the user to perform operations related to the operation of the hot water supply system A. The remote controller R is connected by wire or wirelessly in a communicable manner to the control device C and the heat source control devices (not shown) provided in the first and second gas heat source machines 501 and 502.

[0029] Remote controller R is a terminal device configured to instruct a control device C of the hot water supply system A to perform operation control information such as turning on and off the power supply of the hot water supply system A and setting the hot water storage set temperature (such as the hot water outlet temperature of the hot water discharged from the first and second gas heat source units 501 and 502) in the hot water storage tank 6 in response to an operation of an operation switch (not shown) by the user. The remote controller R is provided with a display for displaying various information of the hot water supply system A. Note that instead of the remote controller R or together with the remote controller R, a mobile terminal such as a smartphone or a tablet terminal communicably connected to the control device C can be used.

[0030] The control device C is composed of one or more electronic circuit units including a CPU, a ROM, a RAM, an interface circuit, etc. Various data such as various operation programs and set values for executing the operation programs are stored in the memory, and the history of the used water supply valve (the first or second water supply valve 15, 16) is also stored. Detection signals of various sensors and valves described above are input to the control device C, and operation control information is input from the remote controller R. Then, the control device C performs operation control of the entire hot water supply system A by performing operation control of the gas heat source units 501 and 502, various pumps 37, 51, 52, and 73, and the water supply valves 15 and 16.

[0031] To outline the main operation control by the control device C, when the hot water outlet terminal 400 is opened, the water supply pressurizing pump 37 is activated to supply the water stored in the water supply tank 2 to the hot water outlet terminal 400 through the water supply forward pipe 3 and the water supply branch pipe 38, and at the same time, supply the water in the water supply tank 2 to the lower layer of the hot water storage tank 6 through the water supply forward pipe 3 and the heating forward pipe 40 under the tank, so as to supply the upper layer of hot water in the hot water storage tank 6 to the hot water outlet terminal 400 through the hot water supply forward pipe 71 (hot water supply operation). Further, when the detected temperature of the third hot water storage temperature sensor 63 installed at the lower part of the hot water storage tank 6 becomes equal to or lower than a predetermined hot water storage start temperature, the first and second heating circulation pumps 51, 52 are activated to supply the hot water in the hot water storage tank 6 from the lower part to the first and second gas heat source machines 501, 502 through the heating forward pipe 40, the first and second heating forward pipes 41, 42, and supply the hot water heated to a predetermined hot water supply temperature by the first and second gas heat source machines 501, 502 to the upper part of the hot water storage tank 6 through the first and second heating return pipes 45, 46 and the heating return pipe 44 (hot water storage operation). Also, when the temperature of the hot water staying in the hot water supply forward pipe 71 and the hot water supply return pipe 72 drops due to the elapse of a predetermined instant hot water start time or the like, the instant hot water circulation pump 73 is activated to send the hot water stored in the hot water storage tank 6 to the hot water supply forward pipe 71 (instant hot water operation). Further, when the water storage amount in the water supply tank 2 decreases, the water from the water supply source is supplied to the water supply tank 2 through the water supply pipe 10 (water supply operation).

[0032] Next, the characteristic configuration of the present invention will be described. That is, in the hot water supply system A of the present embodiment, two water supply pipes are provided, namely the first water supply pipe 11 and the second water supply pipe 12, and water supply valves are provided, namely the first water supply valve 15 and the second water supply valve 16 corresponding to the first water supply pipe 11 and the second water supply pipe 12 respectively. The control device C is characterized in that when performing the water supply operation to the water supply tank 2 by the first and second water supply pipes 11, 12, it performs control to change the number of water supply valves to be opened according to the usage flow rate at the hot water outlet terminal 400. In the present invention, the water supply pipes are not limited to two, and a plurality of three or more may be provided. In this case, water supply valves are also provided for each of the plurality of water supply pipes. The water supply operation to the water supply tank 2 will be described below.

[0033] To start the water supply operation to the water supply tank 2, the control device C first performs the following water supply operation start processing. Referring to the flowchart of FIG. 3, the control device C monitors the outputs of the float sensors 22 to 24, and determines whether the Hi float sensor 23 and the overflow float sensor 22 are OFF (step S01). When both the Hi float sensor 23 and the overflow float sensor 22 are OFF (\"YES\" in step S01), next, it is determined whether the Lo float sensor 24 is ON (step S02). That is, it is confirmed from the output of the Lo float sensor 24 whether the water level in the water supply tank 2 is at or above the Lo water level. When the Lo float sensor 24 is ON (\"YES\" in step S02), that is, when the water level in the water supply tank 2 is at or above the Lo water level, it is determined whether the usage integrated amount at the hot water supply terminal 400 is equal to or greater than a predetermined integrated amount QA (for example, 10 liters) (step S03). When it is equal to or greater than the predetermined integrated amount QA (\"YES\" in step S03), an instruction to start the water supply operation is given (step S04). Here, the usage integrated amount at the hot water supply terminal 400 is the integrated value of the usage flow rate (L / min) at the hot water supply terminal 400 from the time when the Hi float sensor 23 is OFF to this determination time (step S03). The usage flow rate at the hot water supply terminal 400 is the detected flow rate detected by the water volume sensor 36 provided in the water supply forward pipe 32. Note that the integrated value is cleared when the Hi float sensor 23 detects ON.

[0034] On the other hand, in step S02, when the Lo float sensor 24 is not ON (\"NO\" in step YS2), that is, when the Lo float sensor 24 is OFF and the water level in the water supply tank 2 is less than the Lo water level, an instruction to start the water supply operation is given without determining the usage integrated amount at the hot water supply terminal 400 (step S04). Based on the above instruction to start the water supply operation, the control device C performs the processing of controlling the operation of the water supply valve.

[0035] The water supply valve operation control refers to the flowchart in Fig. 4. The control device C first determines whether there is a past experience of supplying water to the water supply tank 2 (step S1). If there is no water supply experience ( "NO" in step S1), the first water supply valve 15 is opened (step S2). At the same time, the control device C stores the first water supply valve 15 as the latest used water supply valve in the history data (step S3). On the other hand, if there is a water supply experience ( "YES" in step S1), the control device C refers to the stored history data and determines whether the used water supply valve indicating the water supply valve (15 or 16) opened last time is the first water supply valve 15 (step S4). If the previous used water supply valve is not the first water supply valve 15 ( "NO" in step S4), the control device C opens the first water supply valve 15 (step S2), and at the same time, stores the first water supply valve 15 as the latest used water supply valve in the history data (step S3). If the previous used water supply valve is the first water supply valve 15 ( "YES" in step S4), the control device C opens the second water supply valve 16 (step S5), and at the same time, stores the second water supply valve 16 as the latest used water supply valve in the history data (step S6). Through the above operations, first, one of the water supply valves (15 or 16) is opened, and the water from the water source is supplied to the water supply tank 2 through one of the water supply pipes (11 or 12).

[0036] Next, the control device C proceeds to step S7 and determines whether to supply water to the water supply tank 2 through the two water supply pipes (two-valve open determination). This two-outlet determination is made by referring to the flowchart of FIG. 5. The control device C determines whether the flow rate used at the hot water outlet terminal 400 is equal to or greater than a predetermined amount Q (for example, 20 L / min) (step S71). At this point of determination, if the flow rate used at the hot water outlet terminal 400 is equal to or greater than the predetermined amount Q (”YES” in step S71), the control device C determines whether the water supply valve that is currently open is the first water supply valve 15 (step S72). If the first water supply valve 15 is currently open (”YES” in step S72), the second water supply valve 16 is opened (step S73). At the same time, the control device C stores the second water supply valve 16 as the latest used water supply valve in the history data (step S74). If the water supply valve that is currently open is not the first water supply valve 15 (”NO” in step S72), the first water supply valve 15 is opened (step S75), and at the same time, the first water supply valve 15 is stored as the latest used water supply valve in the history data (step S76). By performing the above operations to open the first and second water supply valves 15 and 16, water from the water supply source is supplied to the water supply tank 2 from the two water supply pipes of the first and second water supply pipes 11 and 12.

[0037] On the other hand, in step S71, if the flow rate used at the hot water outlet terminal 400 is less than the predetermined amount Q, the control device C determines whether the OFF state of the Lo float sensor 24 has continued for a predetermined time T (for example, 20 seconds) when the Lo float sensor 24 is OFF (step S77). This determination process is when the instruction to start the water supply operation is performed by the OFF of the Lo float sensor 24 (when ”NO” in step S02 of FIG. 3). Mainly, despite opening one water supply valve by the water supply valve operation control (FIG. 4), the water level rise of the water supply tank 2 is slow, and it is a process to determine whether the Lo water level has not been reached within the predetermined time T and the Lo float sensor 24 has not turned ON.

[0038] Then, in step S77, when the OFF state of the Lo float sensor 24 has not continued for a predetermined time T (”NO” in step S77), that is, when the water level in the water supply tank 2 has reached the Lo water level within the predetermined time T and the Lo float sensor 24 is ON, in this case, the control device C returns the process to step S71. In addition, when the predetermined time T has not elapsed since the Lo float sensor 24 was turned OFF, or when the instruction to start the water supply operation is executed when the Lo float sensor 24 is ON and the accumulated usage amount at the hot water outlet terminal 400 is equal to or more than the predetermined accumulated amount QA (when ”YES” in step S03 of FIG. 3), the process is also returned to step S71. On the other hand, in step S77, when the OFF state of the Lo float sensor 24 has continued for the predetermined time T (”YES” in step S77), that is, as described above, when the rise in the water level of the water supply tank 2 is slow, in this case, the control device C shifts the process to step S72 and performs a process of opening a water supply valve that is not currently open (steps S73 to S76), and water is supplied to the water supply tank 2 from the two water supply pipes of the first and second water supply pipes 11 and 12. Thus, the control of the opening operation of the water supply valve is completed.

[0039] After the water supply valve is opened, the control device C performs a closing determination process for the water supply valve in order to stop the water supply. As this closing determination process, for example, when the overflow float sensor 22 is ON or the Hi float sensor 23 is ON, or when a predetermined time (for example, about 3 seconds to 20 seconds) has elapsed since the overflow float sensor 22 was ON or the Hi float sensor 23 was ON, it is determined that the water supply stop condition is satisfied, and all the water supply valves that are open are closed. As a result, the water supply operation to the water supply tank 2 ends. In addition, in the case of the determination of ”NO” in step S77, before returning the process to step S71, the closing determination process for the water supply valve is performed. When the water supply stop condition is satisfied, all the water supply valves that are open are closed, and when the water supply stop condition is not satisfied, the process is returned to step S71. That is, when the usage flow rate of the hot water outlet terminal 400 is less than the predetermined amount Q, the process is repeated between step S71 and step S77 to prevent a situation where the water supply is not stopped.

[0040] (Operational Effects of the Embodiment) As described above, in this embodiment, when performing the water supply operation to the water supply tank 2, the number of water supply valves that are opened according to the usage flow rate at the hot water outlet terminal 400 is changed to one or two. Therefore, the difference between the water supply flow rate to the water supply tank 2 and the usage flow rate at the hot water outlet terminal 400 can be reduced, and the water level fluctuation in the water supply tank 2 can be decreased. As a result, the number of times of opening and closing of the first and second water supply valves 15 and 16 can be reduced. Also, by providing a plurality of water supply pipes 11 and 12 and a plurality of water supply valves 15 and 16, when the usage flow rate at the hot water outlet terminal 400 is large and equal to or more than a predetermined amount Q, the number of water supply valves to be opened is increased. Therefore, by opening both the first and second water supply valves 15 and 16 (in steps S71, S72, S73, and S75 in FIG. 5), a larger water supply flow rate can be ensured for the water supply tank 2. Accordingly, even when the usage flow rate at the hot water outlet terminal 400 is large, the water supply tank 2 can be prevented from running dry, and the durability of the first and second water supply valves 15 and 16 can be improved.

[0041] Also, in this embodiment, the history of the water supply valve that was opened immediately before during the water supply operation to the water supply tank 2 is stored (in steps S3 and S6 in FIG. 4, in steps S74 and S76 in FIG. 5), and the next opening of the water supply valve is caused from a water supply valve different from the stored water supply valve (in steps S4, S2, and S5 in FIG. 4). Thereby, when performing the water supply operation to the water supply tank 2, the water supply valve to be opened can be changed each time, so that the bias of the water supply valve to be used is suppressed, and the durability of the first and second water supply valves 15 and 16 can be further improved.

[0042] Incidentally, when performing the water supply operation to the water supply tank 2, if a plurality of water supply valves are opened from the beginning, when the usage flow rate at the hot water outlet terminal 400 is less than the predetermined amount Q, the water supply flow rate to the water supply tank 2 becomes larger than the usage flow rate, and a certain amount of water is stored in the water supply tank 2 quickly. Therefore, after the water supply valve is opened, it is closed relatively quickly. Also, when performing the water supply operation next time, if the usage flow rate at the hot water outlet terminal 400 is less than the predetermined amount Q, similarly, after opening a plurality of water supply valves, the plurality of water supply valves are closed relatively quickly. As a result, the plurality of water supply valves are frequently opened and closed, which reduces the durability.

[0043] In the present embodiment, when performing the water supply operation to the water supply tank 2, first, one water supply valve is opened (steps S4, S2, S5 in FIG. 4), and then, when the usage flow rate at the hot water outlet terminal 400 is equal to or more than the predetermined amount Q ( "YES" in step S71 in FIG. 5), control is performed to open the water supply valves other than the one water supply valve (steps S72, S73, S75 in FIG. 5). In this way, since the first and second water supply valves 15, 16 are opened one by one, when the usage flow rate at the hot water outlet terminal 400 is less than the predetermined amount Q ( "NO" in step S71 in FIG. 5), if the water level in the water supply tank 2 has risen above the Lo water level ( "NO" in step S77 in FIG. 5), then, when the water supply stop condition is satisfied, in order to end the water supply operation, it is possible not to use the water supply valves other than the water supply valve that was first opened. Also, in this case, since only one water supply valve is opened, the water supply flow rate to the water supply tank 2 does not become larger than the usage flow rate, the difference between the water supply flow rate and the usage flow rate can be reduced, and the water level fluctuation in the water supply tank 2 can be reduced. Therefore, the water supply valve is not closed relatively quickly after being opened. Therefore, the first and second water supply valves 15, 16 are not frequently opened and closed, and the durability of the first and second water supply valves 15, 16 can be improved.

[0044] On the other hand, when the flow rate used at the hot water outlet terminal 400 is large and equal to or greater than a predetermined amount Q (in FIG. 5, “YES” in step S71), in addition to one water supply valve that is first opened, other water supply valves are also opened (in FIG. 5, steps S73 and S75), so that a larger water supply flow rate can be ensured for the water supply tank 2. Also, even if the water supply flow rate to the water supply tank 2 is increased, since the flow rate used at the hot water outlet terminal 400 is large, the difference between the water supply flow rate and the used flow rate does not become large and the water level fluctuation in the water supply tank 2 does not become large. Therefore, the water supply valves are not closed relatively quickly after being opened, and the first and second water supply valves 15 and 16 are not frequently opened and closed. Accordingly, even when the flow rate used at the hot water outlet terminal 400 is large, the water supply tank 2 can be prevented from running dry, and the durability of the first and second water supply valves 15 and 16 can be improved.

[0045] Also, in the present embodiment, during the water supply operation to the water supply tank 2, even if the flow rate used at the hot water outlet terminal 400 is less than the predetermined amount Q (in FIG. 5, “NO” in step S71), when the OFF state of the Lo float sensor 24 continues for a predetermined time T (20 s) (in FIG. 5, “YES” in step S77), both the first and second water supply valves 15 and 16 are opened (in FIG. 5, steps S72, S73, and S75). When the Lo float sensor 24 is OFF, the water storage amount in the water supply tank 2 is in a low state. When the OFF state of the Lo float sensor 24 continues for the predetermined time T, it can be said that the water supply tank 2 is approaching a state of running dry. Therefore, with the above configuration, by opening both the first and second water supply valves 15 and 16, the water supply flow rate to the water supply tank 2 can be increased and the water supply tank 2 can be surely prevented from running dry.

[0046] As described above, according to the hot water supply system A of the present embodiment, in a configuration in which a water supply valve is provided in a water supply pipe that supplies water from a water supply source to the water supply tank 2, when a plurality of water supply pipes are provided in the water supply tank 2 and a water supply valve is provided in each of the plurality of water supply pipes, it is possible to improve the durability of the water supply valve while preventing the water supply tank 2 from running dry.

[0047] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, in the embodiment, after both the first and second water supply valves 15 and 16 are opened, one of the water supply valves is not closed. However, after the two water supply valves 15 and 16 are opened, if the usage flow rate at the hot water outlet terminal 400 decreases to a predetermined amount Q or less, the water supply valve that was opened first may be closed so that only one water supply valve is opened.

[0048] Also, a plurality of three or more water supply pipes and water supply valves may be provided. In this case, in the process of determining the opening of a plurality of water supply valves (corresponding to the process in FIG. 5), a plurality of thresholds (predetermined amount Q) for determining the magnitude of the usage flow rate at the hot water outlet terminal 400 are set step by step. The larger the usage flow rate at the hot water outlet terminal 400, the more water supply valves are opened, and the number of water supply valves opened may be changed one by one according to the usage flow rate. At this time, the history data stored as the used water supply valve during the water supply operation stores the history of the water supply valves opened in the order of use immediately before, and at the next opening of the water supply valve, the water supply valves that have not been used for the longest time in the history data may be opened in order.

[0049] Also, when the water level in the water supply tank 2 drops below the low water level and the low water level float sensor 25 is turned off, the control device C may simultaneously open the first and second water supply valves 15 and 16 to immediately supply a large amount of water to the water supply tank 2 to prevent the water supply tank 2 from running dry. Note that when all such water supply valves are opened simultaneously, the history data is not updated without storing the used water supply valve.

[0050] Also, a water leakage detection means 81 for detecting water leakage in the hot water pressurizing tank unit is provided at the bottom of the housing of the hot water pressurizing tank unit. When the water leakage detection means 81 detects water leakage in the hot water pressurizing tank unit during the water supply operation to the water supply tank 2, all the opened water supply valves may be closed to forcibly stop the water supply operation.

[0051] Further, the overflow pipe 9 may not have an overflow hole 92.

Explanation of Signs

[0052] 1 Hot water supply pressurizing tank unit 2 Water supply tank 3 Water supply pipe 6 Hot water storage tank 9 Overflow pipe 10 Water supply pipe (water supply path) 11 First water supply pipe (water supply path) 12 Second water supply pipe (water supply path) 13 First governor 14 Second governor 15 First water supply valve 16 Second water supply valve 21 Drain port 22 Overflow float sensor 23 Hi float sensor 24 Lo float sensor (Lo water level detection means) 25 Low water level float sensor 31 First water supply pipe 32 Second water supply pipe 33 Check valve 34 Check valve 35 Pressure sensor 36 Water volume sensor (flow rate detection means) 37 Water supply pressurizing pump 38 Water supply branch pipe 39 Check valve 71 Hot water supply pipe 72 Hot water return pipe 81 Leakage detection means 91 Upstream end opening 92 Overflow hole 93 Trap portion 200 Drain pipe 400 Hot water outlet terminal 500 Heat source unit A Hot water supply system C Control device R Remote control

Claims

1. A heating heat source, A hot water storage tank for storing hot water heated by the heating heat source, A water supply tank for storing water from a water supply source, A pump for supplying the hot water in the hot water storage tank and the water in the water supply tank to a hot water outlet terminal, A water supply path for supplying water from the water supply source to the water supply tank, A water supply valve for opening and closing the water supply path, A control device, and comprising: A plurality of the water supply paths are provided, The water supply valve is provided in each of the plurality of water supply paths, Flow rate detection means for detecting the flow rate used at the hot water outlet terminal is provided, The control device performs control to change the number of water supply valves to be opened according to the flow rate used at the hot water outlet terminal during the water supply operation to the water supply tank by the water supply path. A hot water supply system.

2. In the hot water supply system according to Claim 1, The control device stores the water supply valve that was opened immediately before, and at the next time of opening the water supply valve, performs control to open the valve from a water supply valve different from the stored water supply valve. A hot water supply system.

3. In the hot water supply system according to Claim 1 or 2, Lo water level detection means for detecting that the water level in the water supply tank has become lower than a predetermined Lo water level is provided, When the Lo water level detection means detects that the water level is lower than the Lo water level during the water supply operation to the water supply tank, the control device opens a plurality of water supply valves even if the flow rate used at the hot water outlet terminal is less than a predetermined amount. A hot water supply system that performs control.

Images