JP2000205645A - One-can and multi-aqueduct water heater with filtering function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-can and multi-aqueduct water heater with a filtering function capable of raising water used for a thermal sterilization to a thermally sterilizable temperature by little times of ON and OFF of combustions in a short time, and delicately controlling the temperature of the water. SOLUTION: A thermal sterilization executing unit 251 sets solenoid valves 60, 170 so that water is circulated in a thermal sterilization annular route detouring a bathtub 200 through a filtering tank 130 and a circulating pump 70, then drives the pump 70 and then burns a burner 11 in this state, and thermally sterilizes the tank or the like. In this case, a burning area of the burner 11 is increased to a large burning area B from the start of the sterilizing until a predetermined time is elapsed, and then switched to a small burning area A having smaller burning area than this.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a heat exchanger in which a circulation channel connecting a suction port provided in a bathtub and a discharge port to the bathtub and a hot water supply channel for supplying water are passed through a common heat exchanger. Also, the present invention relates to a single-can multi-channel water heater with a filtration function provided with a filtration tank for purifying water in a bathtub and a circulation pump in the middle of a circulation channel.

[0002]

2. Description of the Related Art Conventionally, a so-called 24-hour bathing device in which a filter tank is incorporated in the middle of a circulation channel for circulating bath water so that the bath water can be used for a long period of time without discarding the water is used. Proposed. In such a device, hot water heated to a high temperature of about 65 ° C. by a heater or the like is passed through a filtration tank or the like to heat sterilize in order to kill various bacteria and the like that grow in the filtration tank and the circulation channel. ing.

For example, by providing a bypass and a switching valve in the middle of a circulation channel, a small-scale annular path including a filtration tank and bypassing a bathtub can be formed. Heat sterilization is carried out by circulating the mixture and boiling it.

[0004] In addition, some water heaters having a bath reheating function, a hot water supply function, a hot water supply function, and the like, to which the above-described 24-hour bath function has been added have appeared. In such a water heater, a filtration tank and an ultraviolet lamp are usually arranged in the middle of a circulation channel for reheating. When performing the heat sterilization treatment, a small-scale annular path bypassing the bathtub is formed, and the temperature is raised to a water temperature that can be heat-sterilized by the burner while circulating the water therein. In addition, a so-called one-can-two-channel water heater with a recirculation flow path and a hot water supply flow path passing through a common heat exchanger, incorporating a filter tank, etc., and adding a bathtub water purification function is usually used. The burner burn rate is set to the minimum combustion on the entire surface in the same manner as in normal reheating, and the heat sterilization treatment is performed.

[0005]

During the heat sterilization treatment, a small-scale annular path bypassing the bathtub is switched to reduce the amount of water to be heated. Therefore, a filter tank and the like are incorporated in a one-can-two-channel water heater. Heating for heat sterilization by burning the burner over the entire surface to a minimum like a sword, the heat power is too large to control the water temperature on the annular path side delicately, and the temperature at which heat sterilization is possible (about 65 ° C) And the heat-resistant temperature of the filtration tank (about 6
(8 ° C.) or less, it was difficult to maintain the water temperature within a limited temperature range.

In a one-tank two-channel water heater with a filter tank incorporated therein, when the burner is burned, both the hot water supply side and the reheating side flow paths are heated. If the burner is burned with the minimum combustion on the entire surface, the water staying in the hot water supply flow path exceeds the upper limit temperature before the water in the annular path rises to a temperature at which heat sterilization is possible.
That is, the water in the hot water supply passage exceeds the upper limit temperature for preventing the user from being burned, or causes partial boiling.

For this reason, even before the water temperature on the annular path rises to a temperature at which heat sterilization is possible, the combustion of the burner is temporarily stopped, and the combustion is restarted after the water temperature on the hot water supply path decreases. That is, the intermittent operation must be performed frequently, and there is a problem that it takes a long time from the start of heating to the time when heat sterilization becomes possible, and that various parts such as an ignition device are deteriorated.

The present invention has been made in view of such problems of the prior art, and raises the temperature of water used for heat sterilization to a temperature at which heat sterilization can be performed in a short time with a small number of on / off times of combustion. It is an object of the present invention to provide a single-can multi-channel water heater with a filtration function that can control the temperature of the water while being able to control the temperature.

[0009]

The gist of the present invention to achieve the above object lies in the following inventions. [1] A circulation flow path (50) connecting a suction port (201) provided in a bathtub (200) and a discharge port (202) to the bathtub (200), and a hot water supply flow path for passing water supply ( 30) passes through a common heat exchanger (12), and a filtration tank (130) for purifying water in the bathtub (200) and a circulation pump (70) are connected to the circulation channel (50). A burner (11) for heating the heat exchanger (12) in a single-can multi-channel water heater with a filtration function provided in the middle of the process.
, Bypass path (161), and switching valve (60, 80-1)
20 and 170) and a heat sterilization treatment executing means (251), wherein the burner (11) can switch the combustion area in at least two stages, and the bypass passage (161) is provided with the filtration tank. A predetermined two points of the circulation channel (50) are connected so as to form an annular path for heat sterilization via (130) and the circulation pump (70) and bypassing the bathtub (200). The switching valve (60, 80 to 120, 170) is configured to determine whether the water sent out by the circulation pump (70) flows to the bypass passage (161) and circulates in the annular path for heat sterilization. The heat sterilization process executing means (251) is configured to switch the switching valve (60, 80 to 120, 17) so that water circulates in the heat sterilization annular path.
0), the circulation pump (70) is driven, and the burner (11) is burned to burn water heated to a target temperature in the annular path for heat sterilization for a predetermined time. A sterilization process is performed, and a burning area at the time of burning the burner (11) is set to a large combustion area (B) at the beginning of the heat sterilization process after a predetermined time has elapsed after the heat sterilization process was started. Characterized in that it is switched to a smaller combustion area (A) smaller than this.

[2] The period in which the burner (11) is burned in the large combustion area (B) at the beginning of the heat sterilization treatment is set at a predetermined upper limit by the amount of water staying in the hot water supply passage (30). The single-can multi-channel water heater with a filtration function according to [1], wherein the temperature is set not to exceed the temperature.

[3] The combustion amount when burning the burner (11) at least in the small combustion area (A) is set to the minimum combustion amount in the combustion area [1].
Or a one-can multi-channel water heater with a filtration function according to [2].

[4] When the burner (11) is burned in the small combustion area (A), the burner (11) is intermittently burned, and the length of time for which the burner (11) is burned each time is fixed. The single-can multi-channel water heater with a filtration function according to [1], [2] or [3], wherein the value is set to a value.

[5] The burner based on the water temperature in the heat disinfection annular passage measured after circulating the water in the heat disinfection annular passage for a certain period of time with the combustion of the burner (11) stopped. (11) The one-can multi-channel water heater with a filtration function according to [1], [2], [3] or [4], wherein a timing for next ignition is determined.

The present invention operates as follows. The heat sterilization processing execution means (251) includes a switching valve (60, so that water circulates in a heat sterilization annular path that passes through the filtration tank (130) and the circulation pump (70) and bypasses the bathtub (200).
80 to 120, 170) and then set the circulation pump (7
0) is driven, and in this state, the burner (11) is burned to perform a heat sterilization treatment of the filtration tank (130) and the like. At this time, the combustion area of the burner (11) is set to a large combustion area (B) until a certain time has elapsed after the start of the heat sterilization treatment, and then to a small combustion area (A) having a smaller combustion area. Switch. The large combustion area (B) may be the entire combustion surface of the burner (11) or a part thereof.

As described above, at the beginning of the heat sterilization treatment, heating is performed in the large combustion area (B), and thereafter, the area is switched to the small combustion area (A). The number of times of combustion on / off until the temperature is reduced is reduced, and delicate temperature control near the target temperature becomes possible. Further, for example, if the combustion in the large combustion area (B) is limited to a range in which the water staying in the hot water supply passage (30) does not exceed a predetermined upper limit temperature, the small combustion area (A) can be used from the beginning. The temperature of the water in the annular path can be raised in a shorter time than in the case of burning.

Further, the burner (11) has a small combustion area (A).
In the case where the combustion amount at the time of burning is set to the minimum combustion amount in the combustion area, the effect of reducing the combustion area can be maximized, and more delicate temperature control becomes possible.

When the burner (11) is burned in the small combustion area (A), the burner (11) is intermittently burned, and the length of the burning duration of the burner (11) in each time is set to a fixed value. Since the amount of water flowing through the annular path is as small as about several liters including the filtration tank (130),
Even if the burner (11) is burned with the minimum burning amount of the small burning area (A), the temperature immediately exceeds the upper limit temperature of the heat sterilization, and intermittent burning becomes essential.

At this time, if the combustion duration per operation in the small combustion area (A) is fixedly determined, the temperature in the annular flow path is actually measured, and the burner ( The combustion control can be simplified as compared with the case where the combustion continuation time is controlled in 11). The combustion time fixedly set is, for example, when the water temperature in the annular path falls to the lower limit temperature for heat sterilization, when performing combustion for a fixed time, the water temperature increases from the lower limit temperature for heat sterilization to the upper limit temperature. The combustion time may be measured in advance, and the combustion duration may be fixedly set to a slightly shorter time.

Further, based on the water temperature in the heat disinfection annular passage measured after circulating the water in the heat disinfection annular passage for a certain period of time in a state in which the combustion of the burner (11) is stopped, the burner (11) is turned off. Next, the timing for ignition is determined.

When the water temperature is measured at the outlet side of the filtration tank (130), the water temperature at the measurement point does not rise for a while after the end of combustion because the amount of heat held by the filter medium is large. Therefore, if the burner (11) is feedback-controlled immediately after the stop of combustion based on the water temperature measured at the outlet side of the filtration tank (130), the temperature of the water in the annular path will rise to an unnecessarily high temperature. In addition, by passing through the filtration tank (130) after passing through the heat exchanger (12) and waiting for a certain time after stopping the combustion, the water temperature in the annular path including the filtration tank (130) is averaged. Is done.

Therefore, if the re-ignition timing of the burner (11) is determined on the basis of the water temperature after a certain period of time has elapsed after the stop of combustion, the burner (11) can be determined based on the substantially average water temperature in the annular path including the filter tank (130). Thus, the reignition timing of the burner (11) is determined, and accurate temperature control can be performed. At this time, the measurement of the water temperature is not necessarily performed by the filtration tank (130).
You do not need to do this on the exit side. For example, if the waiting time after stopping the combustion is set to be sufficiently longer than the time for the water to make one round in the annular path, the average water temperature can be measured almost regardless of where the water temperature is measured.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a single-can multi-channel water heater 10 with a filtration function according to an embodiment of the present invention.
Has a 24-hour bath function of pouring hot water into the bathtub 200, purifying the hot water and keeping it warm, and a hot water supply function of supplying hot water to a faucet provided in a kitchen or a bathroom.

The single-can multi-channel water heater 10 with a filtering function is
It has a circulation channel 50 for circulating the water in the bathtub 200 for purification and reheating, and a hot water supply channel 30 for heating the hot water to discharge hot water. Both the hot water supply passage 30 and the circulation passage 50 pass through a common heat exchanger 12 disposed above the burner 11, and are of a so-called one-can-two-water-channel type. The combustion fan 14 is disposed below the burner 20. The supply and exhaust air is supplied to the combustion chamber 1 by the combustion fan 14.
Air is supplied from below to force the supply of air, and exhaust is discharged from the upper part of the combustion chamber 11.

The burner 11 is divided into a combustion surface A and a larger combustion surface B. Burning surface A of burner 11
An ignition device (not shown) is provided in the vicinity of. The combustion gas supplied to the burner 11 is a gas solenoid valve 1
6, 18 and on / off control by the original gas solenoid valve 17. The gas solenoid valves 16 and 18 allow the combustion surface to be switched between the combustion surface A and the combustion surface B simultaneously, the combustion surface A only, and the combustion surface B only. The amount of combustion gas supplied to the burner 11 is controlled by the gas proportional valve 19.
Will be adjusted by

The hot water supply passage 30 is provided with a hot water supply system heat receiving tube 31 which is a pipe portion for receiving heat from the fin plate of the heat exchanger 12.
And a water supply pipe 32 having one end connected to the inlet side of the hot water supply heat receiving pipe 31 and the other end communicating with a water supply source, and a hot water supply heat receiving pipe 3.
1 and a hot water supply pipe 33 extending from the outlet side.
In the middle of the water supply pipe 32, a water amount sensor 34 for detecting a water flow amount is provided.

On the outlet side of the hot water supply system heat receiving pipe 31 of the hot water supply pipe 33, there is a water amount control valve 37 for adjusting the amount of hot water discharged through the hot water supply passage 30, and downstream of the water control valve 37 is a water amount for checking hot water supply. A sensor 38 is mounted.

A heat exchanger is provided between a portion of the water supply pipe 32 near the inlet side of the heat exchanger 12 and a predetermined portion of the hot water supply pipe 33 between the outlet side of the heat exchanger 12 and the water amount control valve 37. A fixed bypass 40 is provided for bypassing the water supply 12 and flowing the water supplied from the water supply pipe 32 directly to the hot water supply pipe 33. In addition, the heat exchanger 12 is bypassed between a predetermined portion of the water supply pipe 32 on the inflow side of the water supply from the water amount sensor 34 and a predetermined portion of the hot water supply pipe 33 between the water amount control valve 37 and the water amount sensor 38. There is provided a variable bypass 41 for flowing water from the water supply pipe 32 into the hot water supply pipe 33. A water amount control valve 42 for adjusting the amount of water flowing into the hot water supply pipe 33 is attached in the middle of the variable bypass passage 41.

The circulation channel 50 is a circulating system heat receiving tube 51 which is a pipe portion for receiving heat from the fin plate of the heat exchanger 12.
A reheating pipe 52 connecting the inlet of the circulating system heat receiving tube 51 and the suction port 201 provided in the bathtub 200; and the discharge port 202 provided in the outlet of the circulating system heat receiving tube 51 and the bathtub 200.
And a reheating steam pipe 53 connecting between them.

The circulating heat receiving pipe 5 of the reheating pipe 53
1 at a predetermined location 54 near the exit side,
A connection pipe 44 branched from the hot water supply pipe 33 is joined between the junction 43 of the water supply sensor and the water amount sensor 38. In the middle of the connecting pipe 44, a pouring switching valve 45 for switching whether the connecting pipe 44 is closed or opened is provided. By opening the pouring switch valve 45, the hot water heated by the hot water supply system heat receiving pipe 31 flows from the junction 54 through the connecting pipe 44 to the circulation flow path 50.
The hot water can be poured into the bathtub 200 through the circulation channel 50.

A flowing water sensor 55 is provided in the middle of the reheating pipe 53 to check the flow of water in the pipe. The first electric three-way valve 60, the circulation pump 70, the second electric three-way valve 80, the third electric three-way valve 90, the fourth electric three-way valve 100, the fifth electric three-way valve Three-way valve 1
10 and a sixth electric three-way valve 120 are arranged. Each of the electric three-way valves 60, 80 to 120 has three connection ports from a first connection port to a third connection port. Each of the electric three-way valves 60, 80 to 120 can communicate between the two connection ports and close the remaining one connection port, and can arbitrarily switch the two communication ports to be connected electrically. It has become.

The reheating pipe 52 enters the first connection port 61 of the first electric three-way valve 60 from the suction port 201 of the bathtub 200 and passes through the circulation connection pump 70 from the second connection port 62 of the first electric three-way valve 60. Then, the first connection port 8 of the second electric three-way valve 80
1 connected. Furthermore, the second of the second electric three-way valve 80
From the connection port 82 to the first connection port 91 of the third electric three-way valve 90, from the second connection port 92 of the third electric three-way valve 90 to the fourth electric three-way valve 100 via the ultraviolet sterilizer 140 and the filtration tank 130. 1 connection port 101, 4th electric three-way valve 1
00 from the second connection port 102 to the first connection port 111 of the fifth electric three-way valve 110 and the second connection port 1 of the fifth electric three-way valve 110
12, leading to the first connection port 121 of the sixth electric three-way valve 120. And the third connection port 12 of the sixth electric three-way valve 120
3 through the flowing water sensor 72 to the inlet side of the circulation system heat receiving tube 51. In the vicinity of the flowing water sensor 72, a sterilizing thermistor 74 for detecting the temperature of water in the pipe is attached.

The first connection port 101 of the fourth electric three-way valve 100
Communicates with the forward exit side 131 of the filtration tank 130 and the filtration tank 1
The pipe extending from the forward entrance side 132 of the third 30 is connected to the second connection port 9 of the third electric three-way valve 90 via the ultraviolet sterilizer 140.
2 are connected. A filter medium is stored inside the filtration tank 130, and water flowing from the forward entrance 132 is purified by removing dust and the like when passing through the filter medium, and is discharged from the forward exit 131. It has become. A bath thermistor 75 for detecting the temperature of the water in the pipe is provided in the middle of the pipe connecting the forward entrance 132 and the second connection port 92 of the third electric three-way valve 90.

The third connection port 83 of the second electric three-way valve 80 and the third connection port 103 of the fourth electric three-way valve 100 are connected by a pipe for backwashing. A drain pipe 150 for draining water to the outside is connected to the connection port 93. The third connection port 11 of the fifth electric three-way valve 110
The pipe extending from 3 joins the drain pipe 150. The second connection port 122 of the sixth electric three-way valve 120 is connected to a second bypass passage 160 branched from a predetermined location between the flowing water sensor 55 and the junction 54 in the reheating steam pipe 53.

The first connection passage 63 of the first electric three-way valve 60 is connected to a first bypass passage 161 branched from a branch point 56 between the discharge port 202 and the flowing water sensor 55 in the additional heating pipe 53. ing. In addition, the solenoid valve 170 is provided on the discharge port 202 side of the branching point 56 in the reheating pipe 53.
A pressure sensor 180 for detecting the water level of the bathtub 200 is provided on the discharge port 202 side of the electromagnetic valve 170.

The single-can multi-channel water heater 10 with a filtering function is
The control unit 250 is provided for controlling various operations such as a hot water supply operation, a pouring operation, a reheating operation, a filtration operation, and a heat sterilization process. The control unit 250 includes a CPU (central processing unit)
And a circuit having a ROM (Read Only Memory) and a RAM (Random Access Memory) as main parts, and perform the functions of a heat sterilization execution unit 251 and a combustion control unit 252. Has become.

Of these, the heat sterilization execution unit 251 includes a combustion state of the burner 11, a driving state of the circulation pump 70,
5, 60, 80 to 120, and 170 are controlled to perform heat sterilization processing. Combustion control unit 25
Numeral 2 controls the combustion of the burner 11.

The control unit 250 includes various valves 45, 60,
80 to 120 and gas solenoid valves 16 to 19, a circulation pump 70, running water sensors 55 and 72, a sterilizing thermistor 74,
Various control components such as a bath thermistor 75 and sensors are electrically connected by a wiring 255 shown in a simplified manner. The controller 250 is connected to a remote controller (not shown) for setting a hot water temperature, receiving instructions for reheating a bath, and the like. This remote control is installed in a bathroom, kitchen or the like.

Next, the operation will be described. Bathtub water filter tank 13
In a normal filtration operation in which purification is performed at 0, arrows 301 to 301 in FIG.
Water circulates in a water passage indicated by 312. To form this state, the first electric three-way valve 60, the second electric three-way valve 80,
The third electric three-way valve 90, the fourth electric three-way valve 100, and the fifth electric three-way valve 110 are set so that the first connection port and the second connection port thereof communicate with each other. The connection port 121 and the third connection port 123 are set to be in communication. Further, the circulation pump 70 is driven by setting the solenoid valve 170 to the open state. Such a filtration operation is performed while a filtration operation switch of a remote control (not shown) is turned on.
It is done continuously.

FIG. 3 shows a flow of the operation when the one-can multi-channel water heater 10 with the filtering function executes the heat sterilization process. When the execution timing of the heat sterilization processing arrives and a heat sterilization command (actually, the heat sterilization flag assigned to a predetermined address in the RAM is turned on) is issued (step S401), the following heat sterilization processing is executed. . Here, every day when a predetermined time such as 3:00 am arrives, a heat sterilization command is issued from a timer unit (not shown).

Although not shown in FIG. 3, when a heat sterilization command is issued, the heat sterilization execution unit 251 temporarily stops the circulation pump 70 and connects the first electric three-way valve 60 to the third connection port. The state is switched to a state where the third connection port 63 and the second connection port 62 communicate with each other, the electromagnetic valve 170 is closed, and arrows 501 to 51 in FIG.
An annular path for heat sterilization indicated by 2 is formed. During the heat sterilization treatment, the temperature of the water is raised to a temperature at which the water can be heat sterilized while circulating the water in the heat sterilization annular paths 501 to 512.

After forming the heat disinfection annular path, the heat disinfection processing execution unit 251 performs an initial bath combustion operation, such as driving the combustion fan 14 to prepurge the combustion chamber, and also drives the circulation pump 70 ( Step S402). Then, only the combustion surface B of the burner 11 is burned at the minimum combustion amount (step S403). In addition, since the ignition device is actually provided on the side of the combustion surface A,
By immediately stopping the gas supply to the combustion surface A, the single combustion of the combustion surface B is started.

The single combustion of the combustion surface B at the minimum combustion amount is performed at the temperature detected by the sterilizing thermistor 74 (in FIG.
h) is performed until the temperature reaches the predetermined rapid startup end reference temperature (step S404). The quick startup end reference temperature is the water temperature at the location of the disinfection thermistor 74 when the water staying in the hot water supply passage 30 reaches a predetermined upper limit temperature after the combustion on the combustion surface B is started. . Therefore, when the water temperature detected by the disinfection thermistor 74 reaches the rapid startup end reference temperature (step S40).
4; Y), by stopping the combustion of the burner 11 (step S405), the water temperature in the hot water supply passage 30 is prevented from exceeding the predetermined upper limit temperature.

The upper limit temperature of the water staying in the hot water supply passage 30 is defined as a temperature at which the user does not get burned even when the hot water supply is started, or a partial boiling in the hot water supply passage 30. Temperature.

In the present embodiment, the rapid startup end reference temperature is set to 57 ° C. based on the measurement performed in advance.
At this time, the water temperature in the heat disinfection annular passage near the outlet of the heat exchanger 12 has risen to about 68 ° C. This 68 ° C
Is slightly lower than the heat resistant temperature of the peripheral members such as the filtration tank 130. Therefore, sterilization thermistor 74
By stopping the combustion at the point in time, hot water exceeding the heat-resistant temperature of the filtration tank 130 or the like is also prevented from flowing into the annular path for heat sterilization. The water temperature in the heat disinfection annular path near the outlet of the heat exchanger 12 is not limited to 68 ° C. as long as it is equal to or lower than the heat resistant temperature of the peripheral member.

After the combustion on the combustion surface B is stopped, the operation of the circulation pump 70 is continued for about 25 seconds while the combustion is stopped, and only the combustion surface A of the burner 11 is burned for 8 seconds with the minimum combustion amount. I do. After that, waiting for 25 seconds with the combustion off and burning the combustion surface A with the minimum combustion amount for 8 seconds are alternately repeated a predetermined number of times (steps S405 to S41).
1) End the initial start-up operation at the start of the heat sterilization process.
The number of times that the combustion surface A is intermittently burned after the combustion on the combustion surface B is stopped in this manner is set in advance so that the entire water in the annular path for heat sterilization almost rises to a reference temperature range suitable for heat sterilization. Determined based on the measurements made.

Thus, at the beginning of the transition to the heat sterilization process,
Combustion by the combustion surface B having a large combustion area is performed within a range in which water in the hot water supply passage 30 does not exceed the upper limit temperature, and thereafter, the combustion surface A having a small combustion area is intermittently burned to form a ring for heat sterilization. Since the water temperature in the channel is raised to a reference temperature range in which heat sterilization can be performed, water used for heat sterilization can be heat sterilized in a short time while preventing the temperature of water staying in the hot water supply passage 30 from exceeding the upper limit temperature. The temperature can be raised to a possible reference temperature range.

Further, since the burner 11 is intermittently burned, the water in the heat sterilizing annular passage partially exceeds the upper limit of the reference temperature range (the temperature determined based on the heat-resistant temperature of the peripheral members such as the filtration tank). While the combustion is turned off, the temperature of the water in the annular path for heat sterilization is averaged while the combustion is turned off, so that the temperature of the water in the path can be uniformly increased. Furthermore, the combustion control is simplified by fixedly setting the combustion continuation time, the combustion off time, and the number of times of on / off of the combustion surface A based on the measurement performed in advance.

After the completion of the initial start-up operation, the operation returns to the warming mode. In the heat retention mode, the water temperature is maintained within the reference temperature range in which heat sterilization can be performed, and the water is circulated in the heat sterilization annular path for a predetermined time (here, 5 minutes). Since the initial start-up operation is finished when the combustion on the combustion surface A is stopped, when the mode is shifted to the heat retention mode, first, the combustion pump is on standby for 30 seconds while driving the circulation pump 70 with the combustion stopped. (Step S412).

After a waiting time of 30 seconds, it is determined whether or not the water temperature detected by the sterilizing thermistor 74 is equal to or lower than the lower limit temperature of the reference temperature range in which heat sterilization is possible (step S41).
3). The reason why the water temperature is measured after waiting for 30 seconds in a state in which the combustion is stopped is that the filter medium existing in the filtration tank 130 has a large calorific value. This is because the water temperature on the side does not rise. It is also to wait for the water temperature in the annular path for heat sterilization to be averaged.

That is, if the combustion of the burner 11 is feedback-controlled immediately after the combustion is stopped based on the water temperature detected by the sterilization thermistor 74 disposed on the outlet side of the filtration tank 130, excessive heating is performed, and the heat sterilization ring is used. The temperature of the water in the path will exceed the heat resistant temperature of the surrounding members. Therefore, for a certain period after the combustion is stopped, the fluctuation of the water temperature detected by the sterilizing thermistor 74 is ignored, and the timing to reignite the burner 11 is determined based on the water temperature measured after a certain standby time. .

When the water temperature detected by the sterilizing thermistor 74 has dropped to the lower limit of the heat sterilizable reference temperature range after the elapse of the standby time (step S413; Y), only the combustion surface A of the burner 11 is fixed. Set combustion duration (8
(Seconds) for the minimum combustion amount (step S41).
4). After the standby time of 30 seconds has elapsed after stopping the combustion (step S415), if the heat sterilization process is to be continued (step S416), the water temperature is detected again by the sterilization thermistor 74, and if necessary, Burner 11 again
Is burned at the minimum burning amount for only 8 seconds.

When the heat sterilization process is completed 5 minutes after the shift to the warming mode (step S416;
Y), the heat sterilization flag is turned off, and the timer for heat sterilization is reset (step S417), and the heat sterilization process ends. Thereafter, the operation shifts to the reverse washing operation, the washing operation, or the normal filtration operation.

The combustion-on time of the combustion surface A is set to a time shorter than the time when the water in the annular path for heat sterilization rises from the lower limit temperature to the upper limit temperature of the reference temperature range in which heat sterilization can be performed. Therefore, even if the combustion surface A is burned at the minimum combustion amount for 8 seconds after reaching the lower limit temperature, the water temperature in the heat sterilization annular path does not exceed the upper limit temperature of the reference temperature range.

Since the combustion ON time for intermittently burning the combustion surface A is fixedly set, the combustion control is simplified. Further, when the water temperature is detected by the sterilizing thermistor 74 disposed on the outlet side of the filtration tank 130, there is a delay in the rise of the detected hot water temperature, so that it is not possible to accurately grasp the timing for turning off the burner 11 combustion. By fixedly controlling the combustion ON time, it is possible to easily control the water temperature so as not to exceed the upper limit temperature of the heat sterilizable reference temperature range.

Since the combustion surface B is burned only at the beginning of the initial start-up, and thereafter the combustion surface A having a small combustion area is burned, the water circulating in the heat disinfection annular passage is as small as several liters. The temperature of the water can be finely controlled, and the temperature can be accurately maintained within a reference temperature range in which heat sterilization is possible. In addition, since the combustion surface A having a small combustion area is burned with the minimum combustion amount and this combustion is performed intermittently, the water staying in the hot water supply passage 30 is prevented from exceeding the upper limit temperature at the same time. .

In the embodiment described above, the burner 11
The water temperature, which is a criterion for determining whether or not to turn on combustion, is set in the filtration tank 1.
Although the detection is performed by the sterilizing thermistor 74 disposed on the outlet side of the filter 30, if the standby time after stopping the combustion is sufficiently long, water circulates in the heat sterilizing annular path at least one or more rounds. The temperature of the water may be measured at any place, not limited to the exit side.

Further, the combustion continuation time and the standby time on the combustion surface A are mere examples, and are not limited to the values shown in the embodiment. Further, in the embodiment, the combustion in the large combustion area is performed on the combustion surface B, and the combustion in the small combustion area is performed on the combustion surface A. However, the present invention is not limited to this. You may make it perform by combustion.

In the embodiment, the initial start-up operation is completed by uniformly repeating the intermittent combustion on the combustion surface A a predetermined number of times after the initial combustion on the combustion surface B.
After the initial combustion in, the mode may be shifted to the heat retention mode immediately.

Further, the combustion continuation time of the combustion surface A during the initial start-up operation and the combustion continuation time of the combustion surface A during the heat retention mode may be the same time as described in the embodiment. Alternatively, another time may be set. Further, the standby time during the initial start-up operation and the standby time during the warming mode may be the same time or different times. Of course, in each case, control is easier at the same time.

In addition, in the above embodiment, an example of a one-can multi-channel water heater with a filtration function capable of performing one-can, two-channel hot water supply and reheating has been described. However, the present invention is not limited to this. In addition, the present invention is effective even if the apparatus includes a single-can multi-channel heat exchanger that heats the hot water supply, reheating, and heating channels with a common heat exchanger. The fuel supplied to the burner may be oil or the like in addition to gas. In the case of petroleum or the like, a burnerless type such as a gun type burner may be used.

[0061]

According to the single-can multi-channel water heater with a filtering function according to the present invention, the burner is burned with a large burning area at the beginning of the heat sterilization, and then switched to a small burning area.
The number of times of combustion on / off until the temperature rises to the target temperature is reduced. Further, delicate temperature control near the target temperature becomes possible, and the hot water temperature is prevented from exceeding the heat resistant temperature of the peripheral members such as the filtration tank. Further, the temperature of the water in the annular passage can be raised in a shorter time than in the case where the combustion is performed in the small combustion area from the beginning.

In the case where the combustion amount when burning the burner with a small combustion area is set to the minimum combustion amount in the combustion area, the effect of reducing the combustion area can be maximized, and more delicate temperature control can be achieved. Will be possible.

Further, when the burner is burned with a small burning area, the burner is intermittently burned and the length of the burning time of the burner at each time is set to a fixed value, so that the combustion control can be simplified. .

[0064] Based on the water temperature in the heat disinfection annular path measured after a certain standby time has elapsed after the burner combustion is stopped, the next time to ignite the burner is determined.
During standby, the water temperature in the annular path including the filtration tank is averaged, so that the water temperature in the annular path can be accurately controlled.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a one-can multi-channel water heater with a filtration function according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a water passage when the one-can multi-channel water heater with a filtration function according to one embodiment of the present invention performs a normal filtration operation.

FIG. 3 is a flowchart showing a heat sterilization process performed by the single-can multi-channel water heater with a filtration function according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a water passage when a one-can multi-channel water heater with a filtration function according to one embodiment of the present invention is executing a heat sterilization process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... One-can multi-channel water heater with a filtration function 11 ... Burner (small combustion surface A, large combustion surface B) 12 ... Heat exchanger 14 ... Combustion fan 30 ... Hot water supply channel 50 ... Circulation channel 60 ... 1st Electric three-way valve 70 Circulating pump 74 Sterilization thermistor 80 Second electric three-way valve 90 Third electric three-way valve 100 Fourth electric three-way valve 110 Fiveth electric three-way valve 120 Sixth electric three-way valve 130 Filtration tank 140 ... Ultraviolet sterilizer 161 ... Bypass path 170 ... Electromagnetic valve 200 ... Bathtub 201 ... Suction port 202 ... Discharge port 250 ... Control unit 251 ... Heat sterilization execution unit 252 ... Combustion control unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsuya Kitayama 3-4 Fukamidai, Yamato-shi, Kanagawa F-term in Gaster Co., Ltd. (Reference) 3L024 CC02 DD02 DD13 DD14 DD17 DD22 DD27 DD28 DD32 DD34 GG04 GG07 GG41 HH28 HH47 4D034 CA06 4D064 AA11 BF34 BF39 BF40

Claims (5)

[Claims] 1. A circulating flow path connecting a suction port provided in a bath tub and a discharge port to the bath tub, and a hot water supply flow path for supplying water pass through a common heat exchanger, and the bath tub is provided. In a one-can multi-channel water heater with a filtration function provided with a filtration tank and a circulation pump for purifying the water in the middle of the circulation channel, a burner for heating the heat exchanger, and a bypass passage , A switching valve, and a heat sterilization processing execution means, wherein the burner can switch its combustion area in at least two stages, and the bypass passes through the filtration tank and the circulation pump; and It connects two predetermined locations of the circulation flow path so that an annular path for heat sterilization bypassing the bathtub is formed, and the switching valve directs water sent out by the circulation pump to the bypass path side. Pour the heat sterilization ring The heat sterilization treatment execution means drives the circulation pump after setting the switching valve so that water circulates in the heat sterilization annular path. And performing a heat sterilization process of circulating water heated to a target temperature by burning the burner in the annular path for heat sterilization over a predetermined time, wherein a combustion area for burning the burner is provided. After a certain period of time has elapsed since the start of the heat sterilization treatment, the large combustion area at the beginning of the heat sterilization treatment is switched to a smaller combustion area smaller than this, and Water channel type water heater. 2. A period in which the burner is burned in the large combustion area at the beginning of the heat sterilization treatment is set to a range in which water staying in the hot water supply passage does not exceed a predetermined upper limit temperature. The single-can multi-channel water heater with a filtering function according to claim 1. 3. The one-can multi-channel type with a filtering function according to claim 1, wherein the combustion amount at the time of burning the burner at least in the small combustion area is set to the minimum combustion amount in the combustion area. Water heater. 4. The method according to claim 1, wherein when the burner is burned in the small combustion area, the burner is intermittently burned, and the length of the burn time of the burner in each time is set to a fixed value. 2. A single-can multi-channel water heater with a filtration function according to 2 or 3. 5. The burner is then ignited based on the temperature of the water in the annular path for heat disinfection measured after circulating the water in the annular path for heat disinfection for a certain period of time with the combustion of the burner stopped. 5. The single-can multi-channel water heater with a filtering function according to claim 1, wherein a time to be determined is determined.