JP2002277056A - Hot-water supplying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-water supplying system capable of effectively utilizing the amount of heat of preheated water and high in safety. SOLUTION: The hot-water supplying system is provided with a hot-water supplying device 54 for heating water utilizing the combustion gas of a combustion burner 52 and a feed water preheating device 56 for preheating water to supply the same. The hot-water supplying device 54 is provided with a heat exchanger 58, an inflow side flow passage 60 connected to the inflow side of the heat exchanger 58, an outflow side flow passage 62 connected to the outflow side of the heat exchanger 58 and a bypass flow passage 64 connecting the inflow side flow passage 60 to the outflow side flow passage 62. The feed water preheating device 56 is provided with a preheating device main body 66 for preheating water and a supplying flow passage 68 for supplying the preheated water from the preheating device main body 66 while the supplying flow passage 68 of the feed water preheating device 56 is connected to the bypass flow passage 64 of the hot-water supplying device 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply system provided with a hot water supply device for heating water using combustion gas of a combustion burner, and a preheating water supply device for preheating and supplying water.

[0002]

2. Description of the Related Art In recent years, utilization of waste heat of a gas engine or the like in a cogeneration system and utilization of solar heat by a solar device have been advanced as effective utilization of energy. To utilize these heats, heat is recovered using a hot water storage tank or a solar panel, water is preheated by the recovered heat, and the preheated water is supplied to a hot water supply device (for example, Japanese Patent Application Laid-Open No. H10-332197). Gazette).

A known hot water supply system of this kind is, for example,
It has a configuration as shown in FIG. In FIG. 7, the hot water supply system includes a hot water supply device 4 having a combustion burner 2.
And a preheating water supply device 6 for supplying preheating water, and an auxiliary hot water supply device 8 for mixing preheating water from the preheating water supply device 6 with water to be supplied to the hot water supply device 4. The hot water supply device 4 includes a heat exchanger 10, and an inflow side flow path 1 is provided at an inflow side of the heat exchanger 10.
2, the output side is connected to the output side flow path 14, and the inflow side flow path 12 and the outflow side flow path 14 are connected via the bypass flow path 16. The auxiliary hot water supply device 8 includes a mixing valve 18, a supply flow path 20 for supplying water (tap water) is connected to one of the inflow sides of the mixing valve 18, and a preheater is connected to the other inflow side of the mixing valve 18. Outflow channel 22 of water supply device 6
Is connected to the outflow side of the mixing valve 18 and the inflow side flow path 12 of the hot water supply device 4.

[0004] In this hot water supply system, the mixing valve 18 of the auxiliary hot water supply device 8 adjusts the mixing amount of the water flowing through the supply flow path 20 and the preheating water flowing through the outflow flow path 22 of the preheating water supply apparatus 6.
Thereby, the temperature of the water supplied to the inflow-side channel 12 of the hot water supply device 4 is adjusted. Bypass flow path 16 of hot water supply device 4
Is provided with a first flow control valve 24, which regulates the flow rate of water flowing through the bypass flow path 16. The outlet flow path 14 of the hot water supply device 4 has a second flow control valve 2
The second flow control valve adjusts the flow rate of hot water flowing out through the outflow-side flow path 14, and controls the flow rate of gas supplied to the fuel supply flow path 28 that supplies fuel gas to the combustion burner 2. A valve 30 is provided, and the gas flow control valve 30 controls the flow rate of the fuel gas flowing through the fuel supply passage 28.

[0005] In this known hot water supply system, if the temperature of the preheating water of the preheating water supply device 6 is higher than a set tapping temperature,
The preheated water from the preheated hot water supply device 6 and the water from the supply flow passage 20 are mixed in the auxiliary hot water supply device 8 to be maintained at the set hot water temperature, and the hot water having reached the set hot water temperature is supplied to the inflow side flow passage 12 and the heat exchanger. The hot water is discharged through the outlet 10 and the outlet channel 14. still,
At this time, the combustion burner 2 does not burn, and the preheated water is not heated. When the temperature of the preheating water of the preheating water supply device 6 is lower than the set hot water temperature, the combustion burner 2 burns,
Preheating water from the preheating water supply device 6 flows through the inflow-side flow path 12, the heat exchanger 10, and the outflow-side flow path 14, and the combustion burner 2
The heat exchange between the combustion gas from the heat exchanger and the preheated water flowing through the heat exchanger 10 is performed, and the preheated water flowing through the bypass passage 16 and the preheated water heated in the heat exchanger 10 are mixed and maintained at the set tapping temperature. When the hot water reaches the set hot water temperature, the hot water flows out through the outflow side flow path 14.

[0006]

However, in a hot water supply system provided with an auxiliary hot water supply device, there are the following problems to be solved. First, the above-described hot water supply system requires an auxiliary hot water supply device 8 in addition to the hot water supply device 4 having the combustion burner 2, and in this connection, the configuration of the hot water supply system becomes complicated and the manufacturing cost is reduced. Get higher. Also, as for the controller, a controller for the hot water supply device and a controller for the auxiliary hot water supply device are required, and the control of these controllers becomes complicated.

Second, in such a hot water supply system, the temperature of the preheating water is somewhat lower than the set tapping temperature (for example, the temperature of the preheating water is 30 ° C at the set tapping temperature of 42 ° C).
In the following case), it is necessary to sufficiently heat the preheated water. Therefore, as described above, the preheated water from the preheated water supply device 6 is passed through the inflow side channel 12, the heat exchanger 10, and the outflow side channel 14. Then, the preheated water is heated in the heat exchanger 10 as required. However, when the temperature of the preheated water is somewhat lower than the set tapping temperature (for example, when the temperature of the preheated water is about 38 to 40 ° C at the set tapping temperature of 42 ° C), it is almost unnecessary to heat the preheated water. Combustion burner 2 of device 4
Therefore, even if the combustion burner 2 is burned with the minimum flame, the preheated water exceeds the set tapping temperature.
Therefore, in this type of conventional hot water supply system, the preheated water from the preheated water supply device 6 and the water from the supply flow path 20 are mixed, and the temperature of the water to be sent to the heat exchanger 10 is reduced to some extent. In this connection, it cannot be said that the amount of heat of the preheated water is fully utilized.

Third, in such a hot water supply system, after the hot water supply device 4 has burned, the water is heated after-heating, and the heat exchanger 1 is heated.
The inside of 0 is in a very high temperature state. In such a state, when hot water maintained at the set hot water temperature by the auxiliary hot water supply device 8 flows through the heat exchanger 4 of the hot water supply device 4, high-temperature hot water remaining inside the heat exchanger 10 is pushed out. Hot water comes to come out. Therefore, in this type of conventional hot water supply system, immediately after the combustion burner 2 of the hot water supply device 4 burns, even if the temperature of the preheating water is higher than the set tapping temperature,
The auxiliary water heater 8 mixes the preheated water with the water from the supply flow path 20 to lower the temperature of the water to be sent to the heat exchanger 10 to a certain extent (to a temperature controllable range). Relatedly, it cannot be said that the heat of preheated water is being used to the fullest.

An object of the present invention is to provide a hot water supply system that can effectively utilize the amount of heat of preheated water and is highly safe.

[0010]

According to the present invention, there is provided a hot water supply device for heating water using combustion gas of a combustion burner, and a preheating water supply device for preheating and supplying water. The hot water supply device is connected to a heat exchanger for exchanging heat between the combustion gas and the water, an inflow side flow path connected to an inflow side of the heat exchanger, and an outflow side of the heat exchanger. An outlet-side flow path; and a bypass flow path connecting the inflow-side flow path and the outflow-side flow path. The preheating water supply device includes a preheating device main body that preheats water, and preheating from the preheating device main body. A hot water supply, comprising a water supply flow path for supplying water, wherein the supply flow path of the preheating water supply apparatus is connected to the bypass flow path or the outflow side flow path of the hot water supply apparatus. System.

According to the present invention, since the outflow passage of the preheating water supply device is connected to the bypass passage or the outflow passage of the hot water supply device, the preheating water from the preheating water supply device flows through the heat exchanger. Instead, water (for example, tap water) supplied through the inflow-side flow path is supplied to the heat exchanger. Therefore, the heat exchange in the heat exchanger is performed between the combustion gas from the combustion burner and the water flowing through the heat exchanger, the heat exchange is performed substantially independently of the temperature of the preheated water, and the temperature in the water heater is increased. The control (that is, the temperature control by the heat exchanger) is in a controllable range, and it is not necessary to supply water to the preheated water after adding water to the preheated water as in the related art, and to effectively use the heat of the preheated water. be able to. In addition, even in a post-boil state immediately after the combustion of the combustion burner, the high-temperature hot water does not flow out of the heat exchanger directly through the outflow-side flow path, and high-temperature hot water is prevented from flowing out of the outflow-side flow path. Can be. The combustion burner may use fuel gas, fuel oil, or the like for combustion.

Further, in the present invention, the combustion burner of the hot water supply device burns when the temperature of the preheated water of the preheating water supply device is lower than a set tapping temperature, and water from the inflow side flow passage is supplied to the heat exchanger. Flows through, the hot water heat exchanged with the combustion gas in the heat exchanger flows through the outflow side flow path, and the preheated water from the preheating water supply device is mixed with the hot water flowing through the outflow side flow path, Further, the combustion burner includes:
When the temperature of the preheated water is higher than the set hot water temperature, combustion is stopped, and water from the inflow-side flow path flows through the bypass flow path and the outflow-side flow path, and flows through the bypass flow path or the outflow-side flow path. Preheated water from the preheated water supply device is mixed with water.

According to the present invention, when the temperature of the preheating water of the preheating water supply device is lower than the set tapping temperature, the combustion burner burns and the water is heated by the water supply device. That is, the water from the inflow-side flow path flows through the heat exchanger, the hot water heat-exchanged with the combustion gas in the heat exchanger flows through the outflow-side flow path, and the pre-heated water is supplied to the hot water flowing through the outflow-side flow path. The preheated water from the device is mixed, and the hot water having the predetermined temperature in this way flows out of the outlet flow path. At this time, water is not supplied to the outflow-side flow path through the bypass flow path, and the preheated water from the preheating water supply device is supplied through the supply flow path and the bypass flow path or through the supply flow path. Sent to Also, since the preheated water does not flow through the heat exchanger, there is no need to add water to lower the temperature as in the past even if the temperature of the preheated water is close to the set tapping temperature. The amount of heat can be used effectively.

When the temperature of the preheated water is higher than the set tapping temperature, the combustion burner does not burn and the water is not heated in the water heater. That is, the water from the inflow side flow path flows through the bypass flow path and the outflow side flow path, and the preheating water from the preheating water supply device is mixed with the water flowing through the bypass flow path or the outflow side flow path. Hot water that has reached the temperature flows out of the outflow channel. At this time, the water from the inflow-side flow path is not supplied to the heat exchanger, and therefore, the water in the heat exchanger does not flow to the outflow-side flow path. Hot water is avoided from flowing out.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hot water supply system according to the present invention will be described below with reference to FIGS. First Embodiment First, a hot water supply system according to a first embodiment will be described with reference to FIGS. FIG. 1 is a simplified diagram showing the entire hot water supply system of the first embodiment. FIG. 2 is a block diagram showing a control system of the hot water supply system of FIG.
FIG. 4 is a flowchart showing control by the control system of FIG. 2; FIG. 4 is a diagram for explaining flows of water and preheated water when heating is not performed by the hot water supply device in the hot water supply system of FIG. 1; FIG. 5 is a diagram for explaining flows of water and preheated water when heating is performed by the hot water supply device in the hot water supply system of FIG. 1.

In FIG. 1, the hot water supply system shown includes a hot water supply device 54 for heating water by a combustion burner 52 and a preheating water supply device 56 for preheating water. The hot water supply device 54 includes a heat exchanger 58 that is heated by the combustion gas from the combustion burner 52. An inflow side flow path 60 is connected to the inflow side of the heat exchanger 58, and an outflow side flow path 62 is connected to the outflow side thereof. The inflow-side flow path 60 and the outflow-side flow path 62 are connected via a bypass flow path 64. The combustion burner 52 may use fuel gas, fuel oil, or the like as fuel.

The preheating water supply device 56 has a preheating device main body 66 for preheating water, and a supply passage 68 for supplying the preheated water of the preheating device main body 66. The channel 68 is connected to the bypass channel 64. The preheating device main body 66 includes a hot water storage tank that stores exhaust heat of the gas engine as hot water, and a solar power generation device that generates hot water using solar heat.
It is composed of hot water storage tanks of equipment.

Referring to FIG. 2 as well, in this hot water supply system, a first temperature sensor 70 and a first flow rate sensor 72 are provided in supply passage 68 of preheating water supply device 56. The first temperature sensor 70 detects the temperature of the preheated water supplied from the preheating device main body 66 through the supply flow path 68, and the first flow rate sensor 70 detects the flow rate of the preheated water flowing through the supply flow path 68. I do. Inflow side flow path 60 (more specifically,
On the upstream side of the connection portion with the bypass flow passage 64), the second
A temperature sensor 74 and a second flow sensor 76 are provided. The second temperature sensor 74 detects the temperature of the water supplied through the inflow-side flow path 60 (when the inflow-side flow path 60 is connected to a water pipe, tap water is supplied). The two flow rate sensor 76 detects the flow rate of the water flowing through the inflow side flow path 60. Further, the outlet side flow path 62 is provided with third and fourth temperature sensors 78 and 80 and a flow control valve 82. The third temperature sensor 78 is disposed upstream of a connection portion with the bypass flow passage 64, detects the temperature of hot water flowing from the heat exchanger 58 through the outflow flow passage 62, and
The fourth temperature sensor 80 is disposed downstream of a connection portion with the bypass flow passage 64, and detects, for example, the temperature of tap water flowing toward a curan (not shown). Further, the flow control valve 82 is disposed downstream of a connection portion with the bypass flow passage 64, and controls the flow rate of the tapping hot water.

In this embodiment, a first mixing valve 84 is provided at a connection portion between the supply passage 68 of the preheating water supply device 56 and the bypass passage 64 of the hot water supply device 54. When the first mixing valve 84 is in the first state, as shown in FIG.
The upstream side of the bypass passage 64, the downstream side thereof, and the feed passage 68 communicate with each other, and water from the upstream side of the bypass passage 64 and preheated water from the feed passage 68 are mixed to form a bypass. In the second state, as shown in FIG. 5, the supply path 68 communicates with the downstream side of the bypass flow path 64, and the supply path 68 is connected to the downstream side of the flow path 64. Is supplied to the downstream side of the bypass flow passage 64 (at this time, the first mixing valve 84 cuts off the communication between the upstream side and the downstream side of the bypass flow passage 64, and accordingly, the inflow side Water from the flow path 60 does not flow to the outflow-side flow path 62 through the bypass flow path 64).

The outflow side flow path 62 and the bypass flow path 64
A second mixing valve 86 is provided at the connection portion with the second mixing valve 86.
In the first state, as shown in FIG. 4, the second mixing valve 86 is connected to the downstream side of the outflow side flow path 62 and the bypass flow path 6.
4 and supplies preheated water (including preheated water mixed with water) from the bypass flow passage 64 to the downstream side of the outflow flow passage 62 (at this time, the second mixing valve 84 Outflow channel 62
The communication between the upstream side and the downstream side is interrupted, so that water (or hot water) from the heat exchanger 58 does not flow to the downstream side of the outflow side flow path 62), and the second state Sometimes, as shown in FIG. 5, the upstream side portion of the outflow side channel 62, the downstream side portion thereof, and the bypass channel 64 communicate with each other.
Preheated water from the heat exchanger 58 and hot water flowing from the heat exchanger 58 to the upstream side of the outflow side channel 62 are mixed and supplied to the downstream side of the outflow side channel 62.

A gas supply passage 88 is connected to the combustion burner 52, and a gas flow regulating valve 90 is provided in the gas supply passage 88. The gas supply channel 88 is connected to a gas buried pipe, a gas cylinder or the like as a gas supply source, and city gas and LP gas as a fuel gas are supplied through the gas supply channel 88. The flow rate of the fuel gas supplied through the flow path 88 is adjusted.

The hot water supply device 54 further includes a controller 92 composed of, for example, a microprocessor (see FIG. 2).
And first to fourth temperature sensors 70, 74, 78, 80
The detection signals from the first and second flow sensors 72 and 76 are sent to the controller 92 and the controller 9
2 is based on these detection signals, various operation signals (operation start signal, operation end signal, etc.) input from a remote controller (not shown), and a setting signal (setting hot water temperature signal, etc.).
And controls the operation of the second mixing valves 84 and 86, the flow control valve 82, and the gas flow control valve 90.

The illustrated controller 92 includes an operation control unit 94, a calorific value calculation unit 96, a temperature comparison unit 98, a temperature comparison unit 100, and a memory 102. The operation control unit 94 includes a first and a second mixing valve 84. , 86, etc., as described later, the calorific value calculating means 96 calculates the calorific value as described later, and the temperature comparing means 98 calculates the set tapping temperature and the temperature of the preheated water (the temperature detected by the first temperature sensor 70). The temperature comparing means 100 compares the set tapping temperature with the temperature of the hot water discharged from the outlet channel 62 (the temperature detected by the fourth temperature sensor 80). In addition, memory 102 stores a set hot water temperature and the like set by a remote controller.

Next, control of the above-described hot water supply system will be described mainly with reference to FIG. 2 and FIGS. 3 to 5.
In order to supply hot water with this hot water supply system, first, the remote control (not shown) is operated to start operation of the hot water supply system (step S1). Next, the tapping temperature is set by operating the remote controller (step S2). So,
A signal of the set hot water temperature is sent to the controller 92 of the hot water supply device 54 using a wire, wireless, infrared, or the like, and stored in the memory 102 thereof. In such a state, for example, when the callan (not shown) of the kitchen (or wash basin, bathroom, etc.) is opened (step S3), the process proceeds to step S4, and the temperature T1 of the preheated water (the first temperature sensor 70) Is determined to be equal to or higher than the set tapping temperature TS (T1 ≧ TS). That is, the temperature comparison means 98 of the controller 92 compares the temperature T1 of the preheated water with the set tapping temperature TS, and the temperature T1 of the preheated water is equal to or higher than the set tapping temperature TS (T1 ≧ T).
S), since heating by the combustion burner 52 is not required, the process proceeds from step S4 to step S5, but the temperature T1 of the preheating water is lower than the set tapping temperature TS (T1 <TS).
Then, heating by the combustion burner 52 is required, so the process proceeds from step S4 to step S6.

In step S5, the controller 92
The operation control means 94 switches the first and second mixing valves 84 and 86 to the first state and holds them. That is, as shown in FIG. 4, the first mixing valve 84 communicates the upstream side of the bypass flow path 64, the downstream side thereof, and the supply flow path 68, and the second mixing valve 86 communicates with the bypass flow path 64. And the downstream side of the outflow side channel 62. Accordingly, water (for example, tap water) from the inflow-side flow path 60 is supplied to the first mixing valve 84 through the upstream side of the bypass flow path 64, and preheated water from the preheat water supply device 56 is supplied to the supply flow path. The water is supplied to the first mixing valve 84 through 68, and the water and the preheated water are mixed at the first mixing valve 84. The preheated water mixed with the water is supplied to the downstream side of the bypass passage 64, the second mixing valve 86 and the outflow passage 62.
The hot water is fed through the downstream side of the hot water outlet, and the hot water is discharged from the open callan (not shown). At this time, the operation control means 94 holds the gas flow control valve 90 in the closed state, and the combustion burner 52 does not burn (step S7).

When the hot tap water flows through the outflow-side channel 62 in this way, the mixing ratio of the first mixing valve 84 is calculated (step S8). In this embodiment, the temperature comparing means 100 includes the temperature of the preheating water from the preheating water supply device 56 (the temperature T1 detected by the first temperature sensor 70) and the temperature of the water from the inflow-side channel 60 (the temperature of the second temperature sensor 74). Detected temperature T2),
The mixing ratio of water and preheated water in the first mixing valve 84 is determined based on the tapping temperature of the outflow side channel 62 (detected temperature T4 of the fourth temperature sensor 80) and the setting tapping temperature (TS) set by the remote controller. Operation is performed as required, and the operation control means 94 controls the first mixing valve 84 so that the mixing ratio of water and preheated water becomes the above calculation result, whereby the temperature of the hot tap water becomes the set hot water temperature. Thus, water and preheated water are mixed (step S9).

The temperature comparing means 100 calculates the temperature (T4) of the hot tap water in the outlet flow path 62 and the set tap temperature (T4).
S) to determine whether they are equal (T4 = TS). When the temperature (T4) of the tapping hot water and the set tapping temperature (TS) are equal (T4 = TS), the process proceeds to step S11, and in this state, the hot water flows out through the outflow-side flow path 62. On the other hand, the temperature of the hot water (T4) is equal to the set hot water temperature (T4).
If not equal to S), the process returns to step S8, and the temperature comparing means 100 again calculates the mixing ratio of the first mixing valve 84 (step S8), and steps S8 to S10 are repeatedly performed.

On the other hand, when the operation proceeds to step S6, the operation control means 94 of the controller 92 switches and holds the first and second mixing valves 84 and 86 to the second state. That is, as shown in FIG. 5, the first mixing valve 84
The second mixing valve 86 communicates the upstream side of the outflow side channel 62, the downstream side thereof, and the bypass channel 64. Therefore, the inflow-side flow path 60
(For example, tap water) is supplied to the second mixing valve 86 through the upstream side of the inflow side channel 60, the heat exchanger 58, and the outflow side channel 62, and the preheated water from the preheat water supply device 56. Are the feed passage 68, the first mixing valve 84, and the bypass passage 64
The water (hot water) from the heat exchanger 52 is supplied to the second mixing valve 86 through the downstream side of the heat exchanger 52.
And preheated water are mixed. Further, the operation control means 94 opens the gas flow control valve 90 (step S12), and the fuel gas is supplied to the combustion burner 52 through the gas supply flow path 88 and the gas flow control valve 90, and the combustion burner 52 The heat is exchanged between the combustion gas generated by the combustion and the water flowing through the heat exchanger 58 to heat the water, and the second mixing valve 86
At this time, the hot water from the heat exchanger 58 and the preheated water from the bypass flow passage 64 are mixed, and the mixed hot water flows out of the opened callan (not shown).

When the hot tap water flows through the outflow-side flow path 62 as described above, first, the amount of heat to be heated by the combustion burner 52 is calculated (step S13). In this embodiment, the calorie calculating means 96 includes a set tapping temperature (TS), a temperature of the preheated water from the preheating water supply device 56 (the temperature T1 detected by the first temperature sensor 70), and a flow rate of the preheated water (the first flow rate sensor). 72, the temperature of the water from the inflow side channel 60 (second
The amount of heat to be heated by the combustion gas from the combustion burner 52 is calculated based on the detected temperature T2 of the temperature sensor 74 and the flow rate of the water (the detected flow rate Q2 of the second flow rate sensor 76),
The operation control means 94 controls the gas flow control valve 90 so that the calorific value of the fuel gas becomes the above-mentioned calculation result, whereby the fuel gas is burned so that the combustion heat amount of the combustion burner 52 becomes the calculated calorie. (Step S14). Note that the required heat quantity QW is generally QW = Q1 × (TS−T1)
+ Q2 (TS-T2).

Next, the mixing ratio of the second mixing valve 86 is calculated (step S15). In this embodiment, the temperature comparing means 100 includes a temperature (T1) of the preheated water from the preheating water supply device 56, a temperature of the hot water from the heat exchanger 58 (a temperature T3 detected by the third temperature sensor 78), and the outflow side flow path 62. Hot water temperature (T4) and the set hot water temperature (TS),
The mixing ratio between the hot water and the preheating water in the second mixing valve 86 is calculated as required, and the operation control means 94 sets the second mixing valve 8 so that the mixing ratio between the hot water and the preheating water becomes the above calculation result.
The hot water and the preheated water are mixed such that the temperature of the hot water is the set hot water temperature (step S16).

Then, in the same manner as described above, the temperature comparing means 100 compares the temperature (T4) of the hot tap water of the outlet flow path 62 with the set hot water temperature (TS) (T4 = T4).
S) is determined. When the temperature (T4) of the hot water and the set hot water temperature (TS) are equal (T4 = TS),
The process proceeds to step S11, and in this state, the hot water is
Take the hot water through 2. On the other hand, if the temperature of the hot tap water (T4) is not equal to the set hot water temperature (TS), step S13
The amount of heat required for heating by the combustion burner 52 is calculated, the gas supply amount of the gas flow control valve 90 is controlled based on the calculation result, and the mixing ratio of the second mixing valve 86 is calculated. The mixing ratio of the second mixing valve 86 is adjusted based on the result of this calculation, and steps S13 to S17
Is repeatedly performed.

When the process proceeds to step S11 as described above, hot water at the set hot water temperature flows out through the outflow channel 62. Thereafter, in step S18, it is determined whether or not the curan (not shown) has been closed. When the callan is in the open state, the flow returns to step S4, and the flow of the above-described steps is repeatedly performed. On the other hand, when the callan is closed, the process proceeds to step S19, in which it is determined whether or not the operation of the hot water supply system has been turned off, and the process returns to step S18 until the operation is turned off. In the above-described hot water supply system, the hot water having the set hot water temperature flows out through the outflow side channel 62 of the hot water supply device 54 as described above.

Second Embodiment Next, a second embodiment of the hot water supply system will be described with reference to FIG. FIG. 6 is a simplified diagram showing the entire hot water supply system of the second embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In FIG.
In the second embodiment, the supply flow passage 68 of the preheating water supply device 56 is located upstream of the outlet flow passage 62 of the hot water supply device 54A, specifically, downstream of the third temperature sensor 78 on the upstream side. Connected to the side. A first mixing valve 84A is provided at a connection portion between the feed passage 68 and the outflow passage 62, and a second mixing valve 86A is provided at a connection portion between the outflow passage 68 and the bypass passage 64. Are arranged. Other configurations of the hot water supply system according to the second embodiment are the same as those of the first embodiment.
The embodiment is substantially the same as the embodiment.

In the second embodiment, if the temperature T1 of the preheated water (the temperature detected by the first temperature sensor 70) is equal to or higher than the set tapping temperature TS (T1 ≧ TS), the first mixing valve 84A is used.
Is held in the first state, communicates the supply flow path 68 of the preheating water supply device 56 and the downstream portion of the upstream side portion of the outflow side flow path 62,
Further, the second mixing valve 86A is held in the first state, and the upstream side of the outflow side channel 62, its downstream side, and the bypass channel 6
4 is communicated. Therefore, the preheating water from the preheating water supply device 56 is supplied to the supply passage 68, the first mixing valve 84A, and the outflow passage 62.
Is supplied to the second mixing valve 86A through the downstream portion of the upstream side portion, and water (for example, tap water) from the inflow-side channel 60 is supplied to the second mixing valve 86 through the bypass channel 64,
The preheating water and the water are mixed by the second mixing valve 86A, and the preheating water mixed with the water flows out through the downstream side of the outflow-side flow path 62. At this time, the water flowing in the inflow-side flow path 60 does not flow downstream through the heat exchanger 58, and the combustion burner 52 does not burn.

The temperature T1 of the preheated water is equal to the set tapping temperature T.
S (T1 <TS), the first mixing valve 84A
, The supply flow path 68 of the preheating water supply device 56,
The upstream portion of the upstream side portion of the outflow side channel 62 and the downstream portion of the upstream side portion thereof communicate with each other, and the second mixing valve 86A is maintained in the second state, and the upstream side portion of the outflow side channel 62 and its The gas flow regulating valve 90 is kept open while communicating with the downstream side. Accordingly, the fuel gas is supplied to the combustion burner 52 through the gas supply passage 88, and the combustion burner 52 burns. In addition, the water from the inflow-side channel 60 flows through the heat exchanger 58, and while flowing through the heat exchanger 58, heat is exchanged with the combustion gas from the combustion burner 52 to be heated. Is supplied to the first mixing valve 84A, and preheated water from the preheating water supply device 56 is supplied to the first mixing valve 84A. In the first mixing valve 84A, the hot water from the heat exchanger 58 and the preheated water from the preheating water supply device 56 are mixed, and the preheated water mixed with the hot water flows out through the downstream side of the outflow-side flow path 62. At this time, the water from the inflow side channel 60 does not flow to the outflow side channel 62 through the bypass channel 64.

As described above, also in the hot water supply system of the second embodiment, the water from the inflow side passage 60 and the preheated water from the preheat water supply device 56 can be supplied in substantially the same manner as in the first embodiment. Thus, the same operation and effect as those of the first embodiment can be achieved. As described above, the embodiments of the hot water supply system according to the present invention have been described. However, the present invention is not limited to these embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

[0037]

According to the hot water supply system of the first aspect of the present invention, the outflow passage of the preheating water supply device is connected to the bypass passage or the outflow side passage of the hot water supply device. Does not flow through the heat exchanger, and the water (for example, tap water) supplied through the inflow-side flow path is supplied to the heat exchanger. Therefore, the heat exchange in the heat exchanger is performed between the combustion gas from the combustion burner and the water flowing through the heat exchanger, the heat exchange is performed substantially independently of the temperature of the preheated water, and the temperature in the water heater is increased. The control is in a controllable range, and it is not necessary to supply water to the heat exchanger after adding water to the preheated water as in the related art, and the heat of the preheated water can be effectively used.

Further, according to the hot water supply system of the present invention, when the temperature of the preheated water of the preheating water supply device is lower than the set tapping temperature, the combustion burner burns, and the water from the inflow-side flow path is heated. Heat is exchanged with the combustion gas while flowing through the exchanger, and the hot water is discharged after the hot water from the heat exchanger and the preheated water from the preheating water supply device are mixed. Also, when the temperature of the preheated water is higher than the set tapping temperature, the combustion burner does not burn, and the water from the inflow side flow path flows through the bypass flow path and the outflow side flow path, and the bypass flow path or the outflow side flow path. The hot water is supplied after the preheating water from the preheating water supply device is mixed with the water flowing through the water. Thus, the hot water at the set hot water temperature can be discharged through the outflow channel of the hot water supply device.

[Brief description of the drawings]

FIG. 1 is a simplified diagram showing an entire hot water supply system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the hot water supply system of FIG.

FIG. 3 is a flowchart showing control by the control system of FIG. 2;

4 is a diagram for explaining flows of water and preheated water when heating is not performed by the hot water supply device in the hot water supply system of FIG. 1;

FIG. 5 is a diagram for explaining flows of water and preheated water when heating is performed by the hot water supply device in the hot water supply system of FIG. 1;

FIG. 6 is a simplified diagram showing an entire second embodiment of a hot water supply system according to the present invention.

FIG. 7 is a diagram schematically showing a conventional hot water supply system.

[Explanation of symbols]

 52 Combustion burner 54, 54A Hot water supply device 56 Preheating water supply device 58 Heat exchanger 60 Inflow side flow path 62 Outflow side flow path 64 Bypass flow path 68 Feeding flow path 70, 74, 78, 80 Temperature sensor 72, 76 Flow rate sensor 84 , 84A First mixing valve 86, 86A Second mixing valve 92 Controller 94 Operation control means 96 Heat quantity calculation means

Claims (2)

[Claims] 1. A hot water supply device for heating water using combustion gas of a combustion burner, and a preheating water supply device for preheating and supplying water to the water, wherein the hot water supply device includes a combustion gas and water. A heat exchanger for exchanging heat between the heat exchanger, an inflow side flow path connected to the inflow side of the heat exchanger, an outflow side flow path connected to the outflow side of the heat exchanger, A pre-heating device for pre-heating water, and a supply flow for supplying pre-heating water from the pre-heating device main body. A hot water supply system, comprising a path, wherein the supply flow path of the preheating water supply apparatus is connected to the bypass flow path or the outflow side flow path of the hot water supply apparatus. 2. The combustion burner of the hot water supply device burns when the temperature of preheated water of the preheating water supply device is lower than a set hot water temperature, and water from the inflow side flow path flows through the heat exchanger, Hot water heat exchanged with the combustion gas in the heat exchanger flows through the outflow-side flow path, and preheated water from the preheating water supply device is mixed with the hot water flowing through the outflow-side flow path, and The burner stops burning when the temperature of the preheated water is higher than the set hot water temperature, and water from the inflow-side flow path flows through the bypass flow path and the outflow-side flow path, and the bypass flow path or the outflow-side flow. The hot water supply system according to claim 1, wherein preheated water from the preheated water supply device is mixed with water flowing in a road.