CN115111771A

CN115111771A - Hot water supply device, method of controlling hot water supply device

Info

Publication number: CN115111771A
Application number: CN202210241801.1A
Authority: CN
Inventors: 高桥凌
Original assignee: Noritz Corp
Current assignee: Noritz Corp
Priority date: 2021-03-23
Filing date: 2022-03-11
Publication date: 2022-09-27
Also published as: US20220307726A1; JP2022147205A

Abstract

The invention provides a hot water supply device for inhibiting scale generation in a heat exchanger and a method for controlling the same. The process performed by the hot water supply apparatus includes: a step (S720) of reading the hot water supply set temperature from the memory; a step (S730, S740, S750) of setting the highest temperature of the tank body for each combustion grade (combustion grade) according to a preset setting mode according to the hot water supply set temperature; a step (S780) of continuing the combustion operation when the operation of the hot water supply device (100) is to be detected when the change of the hot water supply set temperature is not detected (NO at step S770); and a step (S730, S740, S750) of setting the highest temperature of the tank body again for each combustion class (combustion number) when the change of the hot water supply set temperature is detected (YES in step S760).

Description

Hot water supply device, method of controlling hot water supply device

Technical Field

The present disclosure relates to a hot water supply device, a method of controlling the hot water supply device, and more particularly, to control of suppressing precipitation of scale.

Background

Conventionally, when hard water containing a large amount of calcium or the like is used as tap water to be supplied to a hot water supply device, calcium (scale) may be precipitated, attached, and accumulated in a tank body. As a result, heat exchange between the tank body and water in the tank body is inhibited, and an excessive thermal stress is applied to the tank body, which may eventually cause thermal fatigue failure.

As a measure against the adhesion of scale to the tank body, for example, japanese patent laying-open No. 2014-88976 (patent document 1) discloses "a hot water supply device capable of suppressing the deposition of scale (scale) in the heat exchanger". The hot water supply device is characterized by comprising: the cooling device includes a burner 5, an air blowing fan 51, a heat exchanger 31 heated by combustion exhaust gas generated by combustion of the burner 5, a water supply pipe 1 for supplying water to a pipe line 3 of the heat exchanger 31, a hot water outlet pipe 2 for discharging hot water after heating water in the pipe line 3 by heat exchange with the heat exchanger 31, a water discharge pipe 42 branched from the hot water outlet pipe 2, an on-off valve 43 provided in the water discharge pipe 42, and a control unit 14 "(refer to an abstract) for executing a cooling operation of the heat exchanger in which the on-off valve 43 is opened to pass water from the water supply pipe 1 to the water discharge pipe 42 through the pipe line 3 after stopping combustion of the burner 5 by stopping hot water discharge operation. According to the hot water supply device, the temperature of the heat exchanger can be lowered at an early stage by performing the heat exchanger cooling operation of passing water from the water supply pipe to the inside of the pipe of the heat exchanger after the hot water supply operation, and therefore, it is possible to prevent a problem that hot water at a high temperature is stored in the pipe or a back boiling phenomenon occurs. This can suppress the deposition of scale on the pipe of the heat exchanger. "(see paragraph 0018).

Further, Japanese patent laid-open No. 2001-50589 (patent document 2) discloses a technique of "inexpensively preventing boiling of hot water on the outlet side of a heat exchanger of a hot water supplier and generation of drain water in the heat exchanger". The above-described technology is "when the set temperature Ts of the hot water supply device is higher than the high-temperature set temperature THS, when the hot water temperature To is higher than the set temperature Ts, the inner cylinder control temperature TNDS is set To be lower than the high-temperature adjustment temperature Δ Thn determined from the hot water temperature To and the set temperature Ts, and when the hot water temperature To is lower than the set temperature Ts, the inner cylinder control temperature TNDS is set To be higher than the high-temperature adjustment temperature Δ Th and equal To or lower than the boiling prevention temperature TF which is predetermined To prevent the hot water from boiling due To heating of the heat exchanger 30, and combustion of the burner is controlled so that the inner cylinder temperature becomes the set inner cylinder control temperature" (refer To [ abstract ]).

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. 2014-88976

[ patent document 2] Japanese patent laid-open No. 2001-50589

Disclosure of Invention

[ problems to be solved by the invention ]

According to the technique disclosed in patent document 1, since the adhesion of scale is suppressed after the hot water supply is stopped, the effect may be low in terms of suppressing the adhesion of scale when the hot water supply device is used. Further, since the heat exchanger (the tank) is cooled by a cooling operation using water, etc., the temperature of the tank may be lowered more than necessary. Further, when water is passed for cooling, the pipe is rapidly cooled, and there is a possibility that the durability is lowered by thermal shock.

The present disclosure has been made in view of the above-described background, and according to one aspect, discloses a technique for suppressing precipitation of scale when a hot water supply device is used.

[ means for solving problems ]

In accordance with an embodiment, a hot water supply apparatus is provided. The hot water supply device includes: a burner; a tank including a heat exchanger heated by a burner; a water supply path for supplying water to the inlet of the tank; a hot water outlet path for supplying hot water from the outlet of the tank body; a bypass passage for bypassing the tank and connecting the water supply passage and the hot water outlet passage; a first temperature sensor for detecting the temperature of water supplied to the tank; the second temperature sensor is used for detecting the temperature of the hot water at the outlet of the tank body; a third temperature sensor for detecting the temperature of the hot water supplied from the hot water supply device after the bypass passage and the hot water outlet passage are merged; and a control device for controlling the operation of the hot water supply device. The control device receives an input of a set value of the temperature of hot water supplied from the hot water supply device, determines the combustion level of the burner based on the set value and the amount of hot water supplied from the hot water supply device, and controls the combustion operation by the burner in accordance with the maximum temperature of the tank body predetermined in advance in accordance with the combustion level.

In the hot water supply apparatus according to another aspect, the burner burns at a plurality of combustion levels. The maximum temperature is set for each combustion class.

In the hot water supply apparatus according to another aspect, the maximum temperature of the can body when the combustion level of the burner is the smallest is less than the maximum temperature of the can body when the combustion level of the burner is the largest.

In the hot water supply device according to another aspect, when the combustion level is equal to or lower than a predetermined combustion level, the maximum temperature of the tank body when the set value is lower than the predetermined temperature is lower than the maximum temperature of the tank body when the set value is higher than the predetermined temperature.

In another aspect of the hot water supply apparatus, the control device further detects adhesion of the scale to the inside of the heat exchanger based on the temperature at the outlet of the tank, and causes the hot water supply apparatus to perform a predetermined operation based on the detection of the adhesion of the scale to the inside of the heat exchanger.

In the hot water supply device according to still another aspect, the maximum temperature of the tank may be changed based on any one of the temperature of the water supplied to the tank, the temperature of the hot water sent from the tank, the temperature of the hot water supplied from the hot water supply device, a set value, and a hot water supply capacity required by the hot water supply device.

In accordance with another embodiment, a computer-implemented method for controlling a hot water supply apparatus is provided. The method comprises the following steps: receiving an input of a set value of a temperature of hot water supplied from a hot water supply device including a burner and a tank including a heat exchanger heated by the burner; determining a combustion level of the burner based on the set value and an amount of hot water supplied from the hot water supply device; and controlling a combustion operation by the burner in accordance with a maximum temperature of the can body which is predetermined in accordance with the combustion level.

In a method according to another aspect, the burner burns at a plurality of combustion levels, and the maximum temperature is set for each combustion level.

In the method according to another aspect, the maximum temperature of the can body at which the combustion rating of the burner is the smallest is less than the maximum temperature of the can body at which the combustion rating of the burner is the largest.

In the method according to another aspect, in a case where the combustion level is equal to or lower than a predetermined combustion level, the maximum temperature of the can body when the set value is lower than the predetermined temperature is lower than the maximum temperature of the can body when the set value is higher than the predetermined temperature.

A method according to another aspect, further comprising: detecting the adhesion of scale to the interior of the heat exchanger based on the temperature of the outlet of the tank; and causing the hot water supply device to perform a predetermined operation based on the detection of the adhesion of the scale to the inside of the heat exchanger.

In the method according to still another aspect, the maximum temperature of the tank may be changed based on any one of the temperature of the water supplied to the tank, the temperature of the hot water sent from the tank, the temperature of the hot water supplied from the hot water supply device, a set value, and a hot water supply capacity required by the hot water supply device.

In accordance with still another embodiment, there is provided a program for causing a computer to execute the method for controlling a hot water supply apparatus. The program causes the computer to execute the steps of: receiving an input of a set value of a temperature of hot water supplied from a hot water supply device including a burner and a tank including a heat exchanger heated by the burner; determining a combustion level of the burner based on the set value and an amount of hot water supplied from the hot water supply device; and controlling a combustion operation by the burner in accordance with a maximum temperature of the can body which is predetermined in accordance with the combustion level.

In a process according to another aspect, the burner burns at a plurality of combustion levels. The maximum temperature is set for each combustion level.

In the routine according to another aspect, the maximum temperature of the can body at which the combustion level of the burner is minimum is smaller than the maximum temperature of the can body at which the combustion level of the burner is maximum.

In another aspect of the present invention, when the combustion level is equal to or lower than a predetermined combustion level, the maximum temperature of the can body when the set value is lower than the predetermined temperature is lower than the maximum temperature of the can body when the set value is higher than the predetermined temperature.

According to another aspect, the program causes the computer to further perform the steps of: detecting the adhesion of scale to the interior of the heat exchanger based on the temperature of the outlet of the tank; and causing the hot water supply device to perform a predetermined operation based on the detection of the adhesion of the scale to the inside of the heat exchanger.

In the program according to still another aspect, the maximum temperature of the tank body may be changed based on any one of the temperature of the water supplied to the tank body, the temperature of the hot water sent from the tank body, the temperature of the hot water supplied from the hot water supply device, a set value, and a hot water supply capacity required by the hot water supply device.

These and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description, which is to be read in connection with the accompanying drawings.

Drawings

Fig. 1 is a schematic diagram showing a configuration of a hot water supply device according to an embodiment.

Fig. 2 is a block diagram showing an example of the hardware configuration of the control device 110.

Fig. 3 is a graph showing a relationship between the number of the hot water supply device 100 (hot water supply capacity) and the temperature of the tank 102.

Fig. 4 is a diagram showing an example of information set on the operation panel 112 according to an embodiment.

Fig. 5 is a diagram showing an aspect of data storage in the memory 220 of the hot water supply apparatus 100 according to the embodiment.

Fig. 6 is a diagram showing an aspect of saving of data in the memory 220 according to another aspect.

Fig. 7 is a flowchart showing a part of a process executed by a Central Processing Unit (CPU) 210 of the hot water supply apparatus 100 according to an embodiment.

[ description of symbols ]

100: hot water supply device

101: shell body

102: tank body

102 a: exhaust port

103: heat exchanger

104: burner with a burner head

105: air supply fan

106: gas valve

107: spark plug

109: motor with a stator having a stator core

110: control device

111: display unit

112: operation panel

113: flow sensor

114: flow regulating valve

115: bypass flow regulating valve

122A: pipe inlet

123A: piping outlet

141. 142, 143: first to third temperature sensors

180a, 180b, 180 c: piping

190: gas piping

220: memory device

230: input/output circuit

240: electronic circuit

250: bus line

510. 520, 610: watch (A)

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

The structure of the hot water supply apparatus 100 will be described with reference to fig. 1. Fig. 1 is a schematic diagram showing a configuration of a hot water supply device according to an embodiment.

The hot water supply device 100 includes: the temperature control device includes a casing 101, a tank 102, a heat exchanger 103, a burner 104, a blower fan 105, a gas valve 106, an ignition plug 107, a motor 109, a control device 110, a display unit 111, an operation panel 112, a flow sensor 113, a flow rate adjustment valve 114, a first temperature sensor 141, a second temperature sensor 142, a third temperature sensor 143, a pipe 180a, a pipe 180b, a pipe 180c, and a gas pipe 190. Further, the arrows in fig. 1 indicate the flow direction of the fluid. The fluid may contain a cleaning liquid used in a cleaning mode in which the hot water supply device 100 operates to remove hot water, and scale attached to the inside of the heat exchanger 103.

The tank 102, the controller 110, the display unit 111, the flow sensor 113, the flow regulating valve 114, the pipe 180a, the pipe 180b, and the pipe 180c are disposed in the casing 101. Heat exchanger 103, combustor 104, and blower fan 105 are disposed in tank 102. Tank 102 is provided with an exhaust port 102a and an intake port (not shown).

The heat exchanger 103 heats a fluid containing hot water using heat from the burner 104. Specifically, the heat exchanger 103 is configured to exchange heat with the combustion gas generated by the combustor 104. In the example of fig. 1, the heat exchanger 103 has a fin and tube type structure including a plurality of plate-shaped fins and a heat transfer tube penetrating the fins. The heat exchanger 103 is not limited to a fin-tube type. In fig. 1, each part including the heat exchanger 103, the pipe 180a, the pipe 180b, and the pipe 180c constitutes a "hot water supply circuit". The burner 104 corresponds to an example of a "heating portion" that heats the hot water supply circuit.

The combustor 104 generates combustion gas by combusting fuel gas. In a certain aspect, the combustor 104 includes a plurality of combustion devices. The plurality of combustion devices are ignited in accordance with a predetermined combustion level in accordance with the required temperature and amount of hot water. The combustion level may be said to correspond to a so-called "combustion level" required by the hot water supply apparatus 100. For example, the combustion rank is specified to be 1 to 6, and there are cases where the combustor 104 includes 20 combustion devices. As an example of this case, three combustion devices are operated at the combustion level "1", five combustion devices are operated at the combustion level "2", 10 combustion devices are operated at the combustion level "3", 13 combustion devices are operated at the combustion level "4", 15 combustion devices are operated at the combustion level "5", and 20 combustion devices are operated at the combustion level "6". The number of combustion levels is not limited to 6, may be less than 6, or may be more than 6.

The combustor 104 is connected to a gas pipe 190. The gas valve 106 is provided in the gas pipe 190. The ignition plug 107 is disposed above the combustor 104. When the ignition plug 107 generates an ignition spark between targets provided in the burner 104, a flame is generated in a mixture of fuel and air ejected from the burner 104.

The blower fan 105 supplies air necessary for combustion to the combustor 104. The blower fan 105 is configured to be rotatable by being driven by a motor 109. Blower fan 105 introduces air from the intake port into tank 102, and discharges air for combustion from exhaust port 102a to the outside of tank 102.

The first temperature sensor 141 is disposed in the pipe 180a and detects the temperature of the water supplied to the hot water supply device 100. The second temperature sensor 142 is disposed at the outlet of the heat exchanger 103, and detects an outlet temperature (hereinafter, also referred to as "tank temperature") that is the temperature of the hot water immediately after the hot water is discharged from the outlet of the heat exchanger 103. The third temperature sensor 143 detects the temperature of the hot water in which the hot water sent from the pipe 180b and the water sent from the pipe 180c are mixed. In a certain aspect, the first, second, and

third Temperature sensors

141, 142, and 143 include so-called Negative Temperature Coefficient (NTC) thermistors having a characteristic that a resistance value decreases as a Temperature increases.

In a certain aspect, the control device 110 may use the tank temperature detected by the second temperature sensor 142 to detect the occurrence of a scale blockage within the heat exchanger 103. For example, if the scale adheres to the inside of the pipe of the heat exchanger 103, normal heat transfer of the heat exchanger 103 is impaired, and the heat transfer efficiency is lowered. As a result, the heat retained in the heat exchanger 103 increases, and the post-boiling temperature increases when the hot water supply operation is stopped. Therefore, the higher the temperature of the tank body detected by the second temperature sensor 142, the larger the amount of scale deposited can be estimated. Therefore, in one embodiment, the controller 110 compares the detected temperature of the second temperature sensor 142 with a predetermined threshold value, and determines the degree of scale clogging (the amount of scale deposited) based on the degree of the detected temperature exceeding the threshold value.

When the control device 110 detects the clogging with scale, it reports that scale is attached to the heat exchanger 103. For example, the control device 110 displays the above-described concept on the display unit 111. For example, when the display unit 111 includes a red light emitting device, the control device 110 turns on the red light emitting device. On the other hand, in the case where the operation panel 112 includes a monitor, the control device 110 displays a message indicating that scale is attached to the heat exchanger 103 on the monitor.

When the adhesion of the scale is detected, the control device 110 automatically or based on the operation of the user of the hot water supply device 100 switches the operation mode of the hot water supply device 100 to the cleaning mode of the heat exchanger 103, sends the cleaning liquid prepared in advance to the heat exchanger 103, and cleans the heat exchanger 103 to remove the scale. After the heat exchanger 103 is cleaned, the controller 110 may switch the operation mode of the hot water supply apparatus 100 to the normal mode, and may restart the operation of the hot water supply apparatus 100.

In one aspect, the second temperature sensor 142 may be attached to the hot water outlet pipe 180b downstream of the heat exchanger 103, or may be attached to a heat transfer pipe in the heat exchanger 103. As another method for detecting the occurrence of scale clogging, in addition to the second temperature sensor 142 for detecting the tank temperature, for example, a configuration for detecting a decrease in the flow rate of hot water due to scale clogging downstream of the heat exchanger 103 may be adopted.

The

pipes

180a, 180b, and 180c are configured to allow the fluid to flow through the heat exchanger 103. Specifically, the pipe 180a is a pipe for supplying water, the pipe 180b is a pipe for discharging hot water, and the pipe 180c is a pipe for bypassing.

The pipe 180a is connected to the water supply side of the heat exchanger 103, and supplies a fluid (water or the like) from the pipe inlet 122A to the heat exchanger 103 (more specifically, a heat transfer pipe).

The pipe 180b is connected to the hot water outlet side of the heat exchanger 103, and sends the fluid from the heat exchanger 103 to the outside through the pipe outlet 123A.

The pipe 180c forms a bypass passage between the pipe 180a and the pipe 180 b. More specifically, the pipe 180c is connected to the pipe 180a and the pipe 180b, respectively, so as to bypass the fluid supplied from the pipe inlet 122A to the pipe 180a and guide the fluid to the pipe 180 b. The bypass flow rate adjustment valve 115 is connected to the pipe 180 c. The bypass flow rate adjustment valve 115 adjusts the flow rate of the fluid in the pipe 180 c.

The flow rate adjustment valve 114 is provided downstream of the confluence point of the pipe 180b and the pipe 180c, i.e., between the confluence point and the pipe outlet 123A. The flow rate adjustment valve 114 adjusts the delivery rate of the fluid (for example, hot water) from the pipe outlet 123A. The flow rate adjustment valve 114 and the bypass flow rate adjustment valve 115 also function as isolation valves by being completely closed. The respective opening degrees of the flow rate adjustment valve 114 and the bypass flow rate adjustment valve 115 are adjusted by, for example, a stepping motor.

The display section 111 is controlled by the control device 110 to display information. The displayed information includes a set temperature, a current temperature (e.g., hot water temperature), an error when the occurrence of the clogging of the scale is detected, information related to a washing mode of the scale, and the like. In the example of fig. 1, the display unit 111 is configured independently of the operation panel 112, but in another aspect, the operation panel 112 that enables the hot water supply device 100 to be remotely operated may include the display unit 111. In addition, in still another aspect, a speaker for outputting information or warning in sound may also be provided.

The control device 110 outputs power supplied to the hot water supply device 100 via a power plug (not shown) to each unit. The control device 110 controls the operations of the components of the hot water supply device 100 by executing a program stored in the memory. For example, the control device 110 controls the operation (combustion)/stop of the combustor 104 and the supply amount of gas to the combustor 104, and controls the operation/stop of the blower fan 105 and the fan rotation speed during operation.

In another aspect, the controller 110 may output an error to the display unit 111 when the occurrence of scale clogging is detected. In this case, after the error is output, the control device 110 controls each unit to prohibit the combustion operation of the combustor 104. Further, when receiving a start operation for starting the cleaning mode to the hot water supply apparatus 100, the control device 110 controls each unit to start the cleaning mode for cleaning the inside of the heat exchanger 103 with the cleaning liquid. When the cleaning mode is finished, the control device 110 may delete the history of the error report and cancel the prohibition of the combustion operation of the combustor 104. The configuration of the control device 110 will be described later.

[ hardware configuration of control device ]

The configuration of the control device 110 will be described with reference to fig. 2. Fig. 2 is a block diagram showing an example of the hardware configuration of the control device 110. The control device 110 representatively includes a microcomputer. The control device 110 includes: a CPU (Central Processing Unit)210, a memory 220, an input/output circuit 230, and an electronic circuit 240. The CPU 210, the memory 220, and the input/output circuit 230 can perform signal transmission and reception with each other via the bus 250. The electronic circuit 240 is configured to execute predetermined arithmetic processing by dedicated hardware. The electronic circuit 240 is capable of interfacing signals between the CPU 210 and the input/output circuit 230.

The control device 110 is electrically connected to the spark plug 107, the motor 109, the second temperature sensor 142, the flow sensor 113, the display unit 111, and the operation panel 112.

The CPU 210 receives input of output signals (detection values) from the sensors including the second temperature sensor 142 through the input/output circuit 230, respectively. Further, the CPU 210 accepts input of a signal indicating an operation instruction given to the operation panel 112 through the input/output circuit 230. The operation instruction includes, for example, an on/off operation of an operation switch of the hot water supply device 100, a hot water supply set temperature, and various time reservation settings (also referred to as "timer settings"). The CPU 210 controls the operations of the respective components including the spark plug 107 and the motor 109 so that the hot water supply apparatus 100 operates in accordance with the operation instruction.

The CPU 210 can output information indicating the state of the hot water supply apparatus 100 via the display unit 111. The display unit 111 includes a liquid crystal monitor, an organic Electroluminescence (EL) monitor, a lamp, and the like. In another aspect, the CPU 210 may report the state of the hot water supply apparatus using a speaker (not shown) using a sound or melody.

[ relationship between Hot Water supply Capacity and Can temperature ]

The relationship between the hot water supply capacity and the tank temperature will be described with reference to fig. 3. Fig. 3 is a graph showing a relationship between the number of the hot water supply device 100 (hot water supply capacity) and the temperature of the tank 102. In one aspect, the maximum temperature of tank 102 may have a linear relationship with the hot water supply capacity. For example, when the required number (hot water supply capacity) of the hot water supply device 100 is 40, the maximum temperature of the tank 102 is set to about 80 ℃ (176 degrees fahrenheit). On the other hand, if the number (hot water supply capacity) is 70, the maximum temperature of tank 102 is about 70 ℃ (158 degrees fahrenheit).

However, the maximum number (hot water supply capacity) is not always required for the hot water supply set temperature indicated to the hot water supply device 100, and in such a case, a change in the temperature of the tank 102 may cause a change in thermal stress.

Therefore, according to an embodiment, the maximum temperature of the tank 102 may be controlled according to the hot water supply set temperature and the combustion level (so-called combustion level) of the hot water supply device 100. For example, in a certain aspect, temperature control of tank 102 is performed as follows.

When the set temperature ≦ 120 degrees fahrenheit (about 49 degrees celsius), the maximum temperature of the can 102 may be set to 140 degrees fahrenheit (60 degrees fahrenheit) at combustion levels of 1-4. At

combustion levels

5 and 6, the maximum temperature may be set to 176 degrees fahrenheit (═ 80 ℃).

In the case of 120 degrees fahrenheit (about 49 degrees fahrenheit) < the set temperature ≦ 140 degrees fahrenheit (60 degrees fahrenheit), the maximum temperature of the canister 102 may be set to 158 degrees fahrenheit (70 degrees fahrenheit) at combustion levels of 1-4. At

combustion levels

When the set temperature is greater than 140 degrees fahrenheit (═ 60 degrees celsius), the maximum temperature of can 102 is set to 176 degrees fahrenheit (═ 80 degrees celsius) at combustion levels of 1 to 6.

[ temperature setting ]

The temperature setting of the hot water supply apparatus 100 will be described with reference to fig. 4. Fig. 4 is a diagram showing an example of information set on the operation panel 112 according to an embodiment. The operation panel 112 includes, for example, a touch panel. The touch panel displays setting information of the hot water supply device 100 and accepts an operation input from a user to the operation panel 112.

For example, as shown in state a, in one aspect, the operating panel 112 displays 60 ℃ (i.e., 140 degrees fahrenheit) as the set temperature of the hot water supply device 100. When the user presses the "ok" button after setting the temperature to 60 ℃, information indicating that the set temperature is 60 ℃ (140 degrees fahrenheit) is written into the memory 220. Thereafter, the CPU 210 adjusts combustion using the combustor 104 based on the set temperature.

Thereafter, when the user presses the "down" button, as shown in state B, the operation panel 112 may display 45 ℃ (i.e., 113 degrees fahrenheit). When the user presses the "ok" button, information indicating that the set temperature is 45 ℃ is written into the memory 220. Thereafter, the CPU 210 supplies hot water of 45 ℃ by suppressing combustion by the burner 104 based on the set temperature and adjusting the amount of water flowing through the pipe 180c as necessary.

[ data Structure ]

The data structure of the hot water supply apparatus 100 will be described with reference to fig. 5 and 6. Fig. 5 is a diagram showing an aspect of data storage in the memory 220 of the hot water supply apparatus 100 according to the embodiment. Fig. 6 is a diagram showing an aspect of saving of data in the memory 220 according to another aspect.

As shown in fig. 5, in some aspect, memory 220 holds a table 510. The table 510 specifies the maximum temperature of the tank body predetermined for each combustion level of the hot water supply apparatus 100. In table 510, the maximum temperature of can 102 is set to a constant value.

In contrast, according to an embodiment, the hot water supply apparatus 100 may use data specified in table 520 instead of data specified in table 510. For example, when the set temperature of the hot water supply device 100 is set to be greater than 120 degrees fahrenheit (49 degrees fahrenheit) and equal to or less than 140 degrees fahrenheit (60 degrees fahrenheit), the CPU 210 controls combustion by the burner 104 based on the data in the table 520.

That is, table 520 specifies the maximum temperatures of the two stages according to the combustion rank. More specifically, the maximum temperature of canister 102 is switched between 4 and 5 of the combustion level. Therefore, in the case where the amount of hot water required by the hot water supply device 100 can be supplied at a combustion level of "4", the maximum temperature of the tank 102 is controlled to 70 ℃ (158 ° fahrenheit). Thereafter, in a case where the user further opens a faucet (not shown) and the amount of hot water used increases, and thus a combustion level of "6" is required for supplying hot water, the maximum temperature of the tank 102 is controlled to 80 ℃ (176 degrees fahrenheit). That is, the upper limit temperature used for controlling tank 102 is increased.

In one aspect, in a range of a low combustion level (combustion level number) (for example, combustion level "1" to combustion level "4"), the fin tube (not shown) or the fin (not shown) is subjected to a high heat load, and therefore scale may be easily generated. However, according to the setting shown in table 520, the maximum temperature of the can 102 in the above range is lower than the maximum temperature of the can 102 in the range in which the combustion level is high (for example, combustion level "5" and combustion level "6"), and therefore, the generation of scale can be suppressed.

Referring to fig. 6, there may be a case where a user of the hot water supply device 100 lowers the set temperature to 49 ℃. In this case, the CPU 210 may use the data specified in the table 610 instead of the data of the table 520. That is, table 610 sets the maximum temperature of can 102 to 60 ℃ (140 degrees fahrenheit) for combustion class "1" to combustion class "4". The maximum temperature of the tank 102 is maintained at 80 degrees fahrenheit (176 degrees fahrenheit) for combustion class "5" and combustion class "6".

Therefore, if the amount of hot water used by the user of the hot water supply device 100 can be supplied in the range of the combustion level "1" to the combustion level "4", the maximum temperature of the tank 102 is set to 60 ℃ (140 degrees fahrenheit). In one aspect, the hot water supply apparatus 100 can perform the so-called bypass mixing control by mixing the hot water flowing through the pipe 180a and the water flowing through the pipe 180c, and therefore, when the set temperature is set to be low (for example, when the set temperature is 49 ℃ (120 degrees fahrenheit) or less), the hot water supply apparatus can control the temperature of the hot water sent out by the bypass mixing control without maintaining the temperature of the tank 102 at a high temperature. Thereafter, when the amount of hot water required increases and the combustion level rises to 5 or 6, the maximum temperature of the tank 102 may be set to 80 ℃ (176 degrees fahrenheit).

In this way, by changing the maximum temperature of tank 102 in accordance with the set value (hot water supply set temperature) for hot water supply device 100, the maximum temperature of tank 102 is also lowered when the hot water supply set temperature is low, and unnecessary combustion can be suppressed. As a result, thermal stress generated in can 102 is reduced, and thus deterioration in durability of can 102 can be suppressed.

[ control Structure ]

A control structure of the hot water supply apparatus 100 will be described with reference to fig. 7. Fig. 7 is a flowchart showing a part of the processing executed by the CPU 210 of the hot water supply apparatus 100 according to an embodiment.

In step S710, the CPU 210 detects that the power supply of the hot water supply device 100 is on.

In step S720, the CPU 210 reads the set temperature of the hot water supply (for example, table 510, table 520, or table 610) from the memory 220 based on the operation signal from the operation panel 112.

In step S730, CPU 210 sets the maximum temperature of can 102 in the first mode. More specifically, CPU 210 sets the maximum temperature of tank 102 to 60 ℃ (140 degrees fahrenheit) for combustion levels "1" to "4", and sets the maximum temperature of tank 102 to 80 ℃ (176 degrees fahrenheit) for combustion levels "5" and "6".

In step S740, CPU 210 sets the maximum temperature of can 102 in the second mode. More specifically, the CPU 210 sets the maximum temperature of the tank 102 to 70 ℃ (158 degrees fahrenheit) for combustion levels "1" to "4", and sets the maximum temperature of the tank 102 to 80 ℃ (176 degrees fahrenheit) for combustion levels "5" and "6".

In step S750, CPU 210 sets the maximum temperature of can 102 in the third mode. More specifically, CPU 210 sets the maximum temperature of can 102 to 80 ℃ (176 degrees fahrenheit) for combustion levels "1" to "4", and similarly sets the maximum temperature of can 102 to 80 ℃ (176 degrees fahrenheit) for combustion levels "5" and "6".

In step S760, the CPU 210 determines whether or not a change in the hot water supply set temperature is detected. For example, the user may operate the operation panel 112 to change the hot water supply set temperature during use of the hot water supply device 100. When receiving a signal of a new set temperature from the operation panel 112, the CPU 210 may determine that there is a change in the hot water supply set temperature. When determining that the change of the hot water supply set temperature has been detected (YES in step S760), the CPU 210 returns the control to step S720. If not (NO in step S760), the CPU 210 switches the control to step S770.

In step S770, the CPU 210 determines whether or not an instruction to end the operation of the hot water supply apparatus 100 is given. For example, when the user presses a stop button (not shown) on the operation panel 112, the CPU 210 determines that an instruction to end the operation of the hot water supply apparatus 100 is given. When the CPU 210 determines that the instruction to end the operation of the hot water supply apparatus 100 is given (yes in step S770), it ends the operation of the hot water supply apparatus 100. If not (no in step S770), the CPU 210 switches control to step S780.

In step S780, the CPU 210 continues the combustion operation of the hot water supply device 100. In one aspect, when the CPU 210 detects that scale has adhered to the inside of the heat exchanger 103, the operation mode of the hot water supply device 100 is switched to the cleaning mode, and cleaning of the heat exchanger 103 is started. When the cleaning of heat exchanger 103 is finished, CPU 210 switches the operation mode to the normal mode. Thereafter, the CPU 210 returns control to step S760.

Some of the disclosed features may be summarized as follows.

(1) In one aspect, the CPU 210 receives an input of a set value of the temperature of the hot water supplied from the hot water supply device 100. The CPU 210 determines the combustion level of the burner 104 based on the set value and the amount of hot water supplied from the hot water supply device 100. The amount of hot water may also correspond to the so-called required number. CPU 210 controls the combustion operation by burner 104 in accordance with the maximum temperature of can 102 predetermined in accordance with the combustion level.

(2) In a certain aspect, the combustor 104 may combust in multiple combustion levels. The maximum temperature is set for each combustion level. The CPU 210 controls the combustion operation by the combustor 104 in accordance with the maximum temperature set for each combustion level.

(3) In a certain aspect, the maximum temperature of tank 102 at which the combustion rating of combustor 104 is at a minimum is less than the maximum temperature of tank 102 at which the combustion rating of combustor 104 is at a maximum.

(4) In one aspect, when the combustion level is equal to or lower than a predetermined combustion level, the maximum temperature of the tank 102 when the set value is lower than the predetermined temperature is lower than the maximum temperature of the tank 102 when the set value is higher than the predetermined temperature.

(5) In one aspect, CPU 210 also detects the adhesion of scale to the interior of heat exchanger 103 based on the temperature of the outlet of tank 102. The CPU 210 causes the hot water supply apparatus 100 to execute a predetermined operation based on the detection of the adhesion of the scale to the inside of the heat exchanger 103.

(6) In one aspect, the maximum temperature of tank 102 can be changed based on any one of the temperature of water supplied to tank 102, the temperature of hot water sent from tank 102, the temperature of hot water supplied from hot water supply device 100, a set value, and a hot water supply capacity required by hot water supply device 100.

As described above, according to the disclosure in the present specification, the hot water supply apparatus 100 can change the upper limit value (maximum temperature) of the set temperature of the tank 102 according to the hot water supply capacity (so-called number) or the combustion level (so-called combustion level). In this case, the set temperature of can 102 is not set to be higher than necessary. This can suppress the adhesion of scale to the tank 102 at a hot water supply capacity or a combustion level that is frequently used. Since the maximum temperature is set according to the hot water supply capacity or the combustion level, the adhesion of scale to the heat exchanger during use of the hot water supply device 100 can be suppressed without reducing the maximum supply amount of the hot water supply device 100.

In addition, although the hot water supply device 100 may be set individually as a usage mode thereof, the hot water supply device 100 may not always be used with the highest hot water supply capacity. According to the hot water supply device 100 according to the present embodiment, the maximum temperature of the tank 102 is not reduced in the entire region of the supply capacity, but is reduced at a combustion level (combustion order) at which the maximum flow rate of water is not reduced. This can suppress the adhesion of scale while maintaining the specification of the hot water supply device 100.

In addition, canister 102 is no longer heated above the desired temperature, thereby relieving thermal stresses generated in canister 102. As a result, the durability of can 102 can be improved. For example, it is assumed that the durability of can body 102 when the maximum temperature of can body 102 is decreased by about 10 degrees can be 2 times or 3 times the durability of can body 102 when the maximum temperature is not decreased.

The hot water supply device 100 according to the above embodiment is exemplified as a hot water supply device capable of switching hot water supply capacity and combustion level, but the disclosed technical features can also be applied to a hot water supply device that cannot be switched. In this case, the hot water supply device according to another aspect may be configured to be able to increase or decrease its hot water supply capacity itself.

The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. The scope of the present invention is indicated by the claims rather than the description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

[ industrial applicability ]

The disclosed technical features can be applied to a hot water supply device for commercial or home use, a combination boiler (combination boiler), and the like.

Claims

1. A hot water supply apparatus comprising:

a burner;

a tank including a heat exchanger heated by the burner;

a water supply path for supplying water to an inlet of the tank;

a hot water outlet path for supplying hot water from an outlet of the tank;

a bypass passage which bypasses the tank and connects the water supply passage and the hot water outlet passage;

a first temperature sensor for detecting the temperature of water supplied to the tank;

a second temperature sensor for detecting the temperature of the hot water at the outlet of the tank;

a third temperature sensor for detecting a temperature of the hot water supplied from the hot water supply device after the bypass channel and the hot water discharge channel are merged; and

a control device for controlling the operation of the hot water supply device,

the control device is

Receives an input of a set value of the temperature of the hot water supplied from the hot water supply device,

determining a combustion level of the burner based on the set value and an amount of hot water supplied from the hot water supply device,

controlling a combustion operation by the burner in accordance with a maximum temperature of the can body which is predetermined in accordance with the combustion level.

2. The hot water supply apparatus according to claim 1, wherein the burner burns at a plurality of combustion levels,

the maximum temperature is set for each of the combustion levels.

3. The hot water supply apparatus according to claim 1 or 2, wherein the maximum temperature of the tank when the combustion level of the burner is the smallest is smaller than the maximum temperature of the tank when the combustion level of the burner is the largest.

4. A hot water supply apparatus according to any one of claims 1 to 3, wherein in a case where the combustion level is a predetermined combustion level or less, the maximum temperature of the tank when the set value is lower than a predetermined temperature is lower than the maximum temperature of the tank when the set value is higher than the predetermined temperature.

5. The hot water supply apparatus according to claim 4, wherein the control means further detects adhesion of scale to the inside of the heat exchanger based on the temperature of the outlet of the tank, and causes the hot water supply apparatus to perform a predetermined action based on the detection of the adhesion of scale to the inside of the heat exchanger.

6. A method, computer-implemented, for controlling a hot water supply, comprising:

receiving an input of a set value of a temperature of hot water supplied from a hot water supply device including a burner and a tank including a heat exchanger heated by the burner;

determining a combustion level of the burner based on the set value and an amount of hot water supplied from the hot water supply device; and

and controlling a combustion operation by the burner in accordance with a maximum temperature of the can body predetermined in accordance with the combustion level.

7. The method of claim 6, wherein the combustor combusts in a plurality of combustion levels,

the maximum temperature is set for each of the combustion levels.

8. A method according to claim 6 or 7, wherein the maximum temperature of the tank at which the combustion rating of the burner is minimum is less than the maximum temperature of the tank at which the combustion rating of the burner is maximum.

9. A method according to any one of claims 6 to 8, wherein, in the event that the combustion level is below a predetermined combustion level, the maximum temperature of the can body at which the set value is below a predetermined temperature is lower than the maximum temperature of the can body at which the set value is above a predetermined temperature.

10. The method of claim 9, further comprising: detecting adhesion of scale to the interior of the heat exchanger based on a temperature of an outlet of the tank; and

and causing the hot water supply device to perform a predetermined operation based on the detection of the adhesion of the scale to the inside of the heat exchanger.