JP2020186857A - Water heater with instantaneous hot water function, and instantaneous hot water system - Google Patents

Abstract

To provide a water heater with an instantaneous hot water function and an instantaneous hot water system free from waste of energy for heat insulation, and degradation of usability.SOLUTION: In a water heater 1 with an instantaneous hot water function which includes a burner unit 4 and a heat exchanger 5, a water supply pipe 18 and a hot water supply pipe 19 connected to the heat exchanger 5, a return pipe 26 connected to the water supply pipe 18 and including a circulation pump 27, and a controller 35, and in which hot water supplied from the hot water supply pipe 19 is returned to the return pipe 26 through external piping 30 by connecting the hot water supply pipe 19 and the return pipe 26 by the external piping 30, so that a circulation passage from the water supply pipe 18 to the heat exchanger 5 is formed, a water volume sensor 23 is disposed to detect usage of hot water from the circulation passage, and the controller 35 stores water passing by the water volume sensor 23 without operating the circulation pump 27 as use record, and can create a heat insulation schedule to operate the circulation pump 27 according to the stored use record.SELECTED DRAWING: Figure 1

Description

The present invention is a water heater with an immediate hot water function capable of immediately supplying hot water from a hot water tap of an external pipe by circulating hot water between an external pipe and a pipe inside the appliance and heating it with a heat exchanger to keep it warm. Regarding an immediate hot water system using a water heater.

A water heater is known to have a hot water function by connecting a return pipe provided with a circulation pump to a water supply pipe connected to a heat exchanger (see, for example, Patent Document 1). In this water heater with an instant hot water function, by connecting the hot water outlet pipe and the return pipe with an external pipe, it is possible to construct an instant hot water system in which a circulation path is formed by the hot water outlet pipe, the external pipe, the return pipe and the water supply pipe. .. Heat retention operation is possible by heating with a heat exchanger while circulating hot water with a circulation pump in this circulation path, and immediate hot water supply can be performed by opening the hot water tap provided in the external pipe.

Japanese Unexamined Patent Publication No. 2004-286397

In the instant hot water system using this instant hot water function water heater, the circulation pump is operated regularly after a predetermined time, and the timing when the hot water is actually used is not taken into consideration. The heat-retaining operation was performed even though it was not performed, and energy was wasted, or the heat-retaining operation was not performed immediately even though it was used, which impaired usability.

Therefore, an object of the present invention is to provide a water heater with an immediate hot water function and an immediate hot water system that do not waste energy related to heat retention or impair usability.

In order to achieve the above object, the invention according to claim 1 controls a burner and a heat exchanger, a water supply pipe connected to the heat exchanger, a hot water pipe connected to the heat exchanger, and a burner. By providing a control means and connecting the hot water pipe and the water supply pipe with an external pipe, the hot water discharged from the hot water pipe returns to the water supply pipe via the external pipe and reaches the heat exchanger. It is a water dispenser with an immediate hot water function that can be formed and the control means can control the circulation pump provided in the circulation path.
Equipped with hot water detection means to detect the use of hot water from the circulation route
The control means is characterized in that it can store the usage record of hot water by the hot water detection means that does not involve the operation of the circulation pump, and can create a heat retention schedule for operating the circulation pump according to the stored usage record.
According to the second aspect of the present invention, in the configuration of the first aspect, the usage record is divided into a predetermined number of time zones, and the usage history of hot water in each divided time zone is divided by a predetermined number of days. It is characterized by being aggregated.
According to the third aspect of the present invention, in the configuration of the first or second aspect, a return pipe having one end connected to a water supply pipe and the other end connecting to an external pipe is provided in the housing, and the circulation pump is a return pipe. It is characterized in that it is provided in.
In order to achieve the above object, the invention according to claim 4 is an immediate hot water system, and between the hot water supply pipe and the hot water supply pipe of the water supply device with the immediate hot water function according to any one of claims 1 to 3. The circulation pump is provided in the circulation path by connecting the two with an external pipe, and the circulation pump is operated according to the heat retention schedule created by the control means.

According to the inventions of claims 1 and 4, the heat retention operation can be executed at an accurate timing according to the usage record. Therefore, the energy related to heat retention is not wasted or the usability is not impaired.
According to the invention of claim 2, in addition to the above effect, the usage record divides one day into a predetermined number of time zones, and the usage history of hot water in each divided time zone is divided into a predetermined number of days. Since it is a total of only the data, it is possible to grasp the appropriate usage record and improve the reliability of the heat retention schedule.
According to the third aspect of the present invention, in addition to the above effects, since the return pipe and the circulation pump are provided in the housing, the immediate hot water system can be easily constructed.

It is the schematic of the immediate hot water system. It is a flowchart of heat retention schedule creation and heat retention control. It is explanatory drawing of the usage record. It is the schematic which shows the modification example of the immediate hot water system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a water heater with an immediate hot water function (hereinafter, simply referred to as a “water heater”) 1 and an immediate hot water system S. The instant hot water system S includes a water heater 1 and an external pipe 30 for circulation connected to the water heater 1.
First, in the water heater 1, a combustion chamber 3 having three burner units 4, 4, ..., a heat exchanger 5, and an exhaust hood 6 is installed in the housing 2 from below. On the bottom surface of the housing 2, a gas connection port 7 to which an external gas pipe is connected, a water supply connection port 8 to which an external water supply pipe is connected, a hot water supply connection port 9 to which an external hot water supply pipe is connected, and a return A connection port 10 is provided.
The burner units 4, 4, ... Are composed of a plurality of burners having different numbers from each other, and a gas pipe 11 having a main solenoid valve 12 and a proportional control valve 13 is connected to the gas connection port 7 from the gas pipe 11. The burner unit 4 is connected to each of the branched branch pipes 14, 14, ..., Through the on-off valve 15. A fan 16 for supplying combustion air to the burner unit 4 is provided in the lower part of the combustion chamber 3.

The heat exchanger 5 is a fin tube type provided with a heat transfer tube that serpentinely penetrates a plurality of fins arranged side by side at predetermined intervals in the thickness direction, and a water supply connection port is provided at the inlet end of the heat transfer tube. A water supply pipe 18 connected to 8 is connected, and a hot water supply pipe 19 connected to a hot water supply connection port 9 is connected to the outlet side end of the heat transfer pipe. A bypass pipe 20 that bypasses the heat exchanger 5 is connected between the water supply pipe 18 and the hot water outlet pipe 19.
Further, on the upstream side of the connection portion of the bypass pipe 20 in the water supply pipe 18, a water side on-off valve 21, a water entry temperature sensor 22 such as a thermistor for detecting the water entry temperature, and a water amount sensor 23 for detecting the amount of water are provided. ing. Further, an outlet temperature sensor 24 such as a thermistor for detecting the outlet temperature from the heat exchanger 5 is provided on the upstream side of the connection portion of the bypass pipe 20 in the hot water discharge pipe 19, and the hot water discharge is on the downstream side of the connection portion. A hot water temperature sensor 25 such as a thermistor that detects the temperature is provided.

Then, a return pipe 26 having a circulation pump 27 and a check valve 28 located on the discharge side thereof is connected between the return connection port 10 and the water supply pipe 18 on the upstream side of the water amount sensor 23. There is.
The external pipe 30 is connected between the hot water supply connection port 9 and the return connection port 10 and includes a plurality of hot water supply plugs 31, 31 ... One of the hot water taps 31 is for supplying hot water to the bathtub 32.
As a result, the hot water discharged from the hot water pipe 19 returns to the return pipe 26 through the external pipe 30, reaches the heat exchanger 5 via the water supply pipe 18, and forms a circulation path in which the hot water is discharged from the hot water pipe 19 again. Will be done.

In the immediate hot water system S configured as described above, when the operation switch provided on the controller 35 or the remote controller 36 is pressed, the controller 35 operates the circulation pump 27 to circulate hot water in the circulation path. At the same time, the main solenoid valve 12 and the on-off valve 15 are opened to supply fuel gas to the burner unit 4, and the fan 16 is driven to perform ignition control to burn the burner unit 4. Then, the controller 35 controls the opening degree of the proportional control valve 13 and the rotation speed of the fan 16 so as to reach the set temperature set by the controller 35 or the remote controller 36, and performs the heat retention operation. Therefore, when any one of the hot water supply taps 31 is opened, immediate hot water supply at a set temperature becomes possible.

On the other hand, after the system is installed, the controller 35 records the usage history of hot water by opening the hot water tap 31 every day, aggregates it in one week, and creates and creates a heat retention schedule based on the aggregated usage record. The heat retention operation by the circulation pump 27 is performed based on the heat retention schedule. Hereinafter, the heat retention schedule creation and heat retention control will be described with reference to the flowchart of FIG.
When the water amount sensor 23 detects the passage of water in the circulation path in step 1 (hereinafter simply referred to as “S”) 1, it is determined in S2 whether or not the circulation pump 27 is in operation. Here, if the circulation pump 27 is in operation, it returns to S1 on the assumption that water is flowing due to the heat retention operation.
If the circulation pump 27 is not in operation according to the determination in S2, the controller 35 stores in a storage unit (not shown) in S3, assuming that the hot water is used by opening the hot water supply plug 31. As shown in FIG. 3, this memory is stored as a usage history for each time zone by dividing the day into, for example, every 3 hours and recording the presence / absence of use in each of the divided bits.

Next, it is determined in S4 whether or not 24 hours have passed. Here, if 24 hours have not passed, the user returns to S1 and saves the usage history for each time zone again. If the passage of 24 hours is confirmed in S4, the daily usage history is for one week in S5. Determine if it has been accumulated. If there is no accumulation for one week here, the bit is shifted to a new 24-hour bit in S6 and the processing from S1 is repeated.
On the other hand, in S5, when it is confirmed that the accumulation of usage history has reached one week, in S7, the usage history in each time zone is totaled to calculate the usage record for one week, and the usage record is calculated. Create a heat retention schedule for operating the circulation pump 27 from. This is, for example, a time zone when the usage record for one week is a predetermined number or more (for example, in FIG. 2, 3:00 am to 6:00 am, 6:00 am to 9:00 am, 6:00 pm to 9:00 pm when the usage record is 3 or more. The schedule is such that (hours, 9:00 pm to 12:00 pm) are set as the time zone for operating the circulation pump 27.

Then, in S8, the circulation pump 27 is operated based on the created heat retention schedule. This is done by continuously operating the circulation pump 27 for a predetermined time at the beginning of the corresponding time zone, or intermittently operating the circulation pump 27 at predetermined time intervals within the corresponding time zone.
Even during the heat retention operation based on the heat retention schedule, the processing after S1 is repeated to save the usage history for each time zone and calculate the usage record for one week, and if the usage record changes, it corresponds to it. The heat retention schedule (time zone for executing the operation) is changed.

As described above, according to the water heater 1 and the immediate hot water system S of the above-described form, the water amount sensor 23 (hot water detection means) for detecting the use of hot water from the circulation path is provided, and the controller 35 (control means) is a circulation pump. The water flow by the water amount sensor 23 that does not involve the operation of the 27 is memorized as the usage record of hot water, and the heat retention schedule for operating the circulation pump 27 is created according to the memorized usage record, so that the timing is accurate according to the usage record. Insulation operation becomes feasible. Therefore, the energy related to heat retention is not wasted or the usability is not impaired.
In particular, here, the usage record is obtained by dividing a day into a predetermined number of time zones and totaling the usage history of hot water in each divided time zone for a predetermined number of days. It can be grasped and the reliability of the heat retention schedule is improved.
Further, since the water heater 1 includes a return pipe 26 and a circulation pump 27 inside the housing 2, the immediate hot water system S can be easily constructed.

In the above form, the heat retention schedule is created by calculating the usage record after the immediate hot water system is installed. However, the heat retention operation is performed according to the heat retention schedule predicted in advance, and the heat retention schedule is set according to the usage record. You may try to update.
Further, the division of the time zone is not limited to the above-mentioned form, and the time zone may be lengthened or divided into smaller pieces. The total number of days is not limited to one week, and may be a short number of days, or conversely a long number of days, or the time zone to be divided for each season and the number of days to be totaled may be changed.
In addition, the configuration of the water heater is not limited to the above-mentioned form, the number of burner units can be increased or decreased, and the present invention can be applied to a latent heat recovery type or the like equipped with an auxiliary heat exchanger.

In the above embodiment, a return pipe and a circulation pump are provided in the housing and connected to the external pipe. However, as shown in FIG. 4, the return pipe is eliminated and the water pipe 33 connected to the water supply pipe 18 is connected. An external pipe 30 may be connected to form a circulation path, and the external pipe 30 may be provided with a circulation pump 27 and a check valve 28. In this case, the circulation pump 27 may be provided in the water pipe 33, or may be provided in the water supply pipe 18 on the upstream side of the water amount sensor 23.

1 ・ ・ Water heater with immediate hot water function, 2 ・ ・ Housing, 3 ・ ・ Combustion chamber, 4 ・ ・ Burner unit, 5 ・ ・ Heat exchanger, 6 ・ ・ Exhaust hood, 7 ・ ・ Gas connection port, 8 ・・ Water supply connection port, 9 ・ ・ Hot water supply connection port, 10 ・ ・ Return connection port, 11 ・ ・ Gas pipe, 16 ・ ・ Fan, 18 ・ ・ Water supply pipe, 19 ・ ・ Hot water outlet pipe, 21 ・ ・ Water side on-off valve, 22 ... Water inlet temperature sensor, 23 ... Water volume sensor, 24 ... Outlet temperature sensor, 25 ... Hot water temperature sensor, 26 ... Return pipe, 27 ... Circulation pump, 30 ... External piping, 31 ... Hot water tap , 32 ... Bath, 35 ... Controller, 36 ... Remote control, S ... Instant hot water system.

Claims (4)

With a burner and heat exchanger,
The water supply pipe connected to the heat exchanger and
The hot water pipe connected to the heat exchanger and
A control means for controlling the burner is provided.
By connecting the hot water outlet pipe and the water supply pipe with an external pipe, a circulation path is formed in which the hot water discharged from the hot water supply pipe returns to the water supply pipe via the external pipe and reaches the heat exchanger. A water heater with an immediate hot water function capable of controlling the circulation pump provided in the circulation path by the control means.
A hot water detection means for detecting the use of hot water from the circulation path is provided.
The control means can store the usage record of hot water by the hot water detection means that does not involve the operation of the circulation pump, and can create a heat retention schedule for operating the circulation pump according to the stored usage record. A featured water heater with an immediate hot water function. The first aspect of the present invention is characterized in that one day is divided into a predetermined number of time zones, and the usage history of hot water in each of the divided time zones is totaled for a predetermined number of days. The water heater with the immediate hot water function described. 1. The water heater with the immediate hot water function described in 2. The control by connecting the hot water outlet pipe and the water supply pipe of the water heater with an immediate hot water function according to any one of claims 1 to 3 with the external pipe and providing the circulation pump in the circulation path. An immediate hot water system characterized in that the circulation pump is operated according to a heat retention schedule created by means.

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