JP2018141601A - Water heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heating device capable of accurately determining the end of the lifetime of a neutralizer with a simple configuration.SOLUTION: A water heating device includes a combustion device 6, a heat medium circulation circuit 1, a primary heat exchanger 2 for recovering sensible heat of combustion gas, a secondary heat exchanger 3 for recovering latent heat of the combustion gas, a neutralizer 15 for neutralizing drain generated in the secondary heat exchanger, a temperature sensor 12, and a control device 10. The temperature sensor 12 detects a temperature of a heat medium output from the primary heat exchanger 2. The control device 10 controls the combustion device 6 so that the temperature of the heat medium supplied to a hot water terminal is to be at a set temperature on the basis of a detection value of the temperature sensor 12. The control device 10 further estimates a drain generation amount on the basis of the detection value of the temperature sensor 12 and the set temperature, and determines the lifetime of the neutralizer 15 with the usage of the estimated drain generation amount.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water apparatus, and more particularly to a hot water apparatus having a heat exchanger that recovers sensible heat and latent heat of combustion gas.

  A hot water apparatus capable of recovering sensible heat and latent heat of combustion gas is known. This type of hot water device is also referred to as a latent heat recovery type hot water device, has high heat exchange efficiency, and contributes to energy saving. In the latent heat recovery type hot water apparatus, strongly acidic drain is generated when the latent heat of the combustion gas is recovered. This drain is collected into the neutralizer, neutralized with the neutralizer filled in the neutralizer, and discharged to the outside of the apparatus.

  The neutralizing agent is consumed by neutralizing the drain. Therefore, for example, in Japanese Patent No. 5555718 (Patent Document 1), the consumption of the neutralizing agent is assumed in accordance with the combustion state, and is predetermined when the consumption of the neutralizing agent is assumed to reach a predetermined level or more. The structure of the hot water apparatus which alert | reports this is shown.

Japanese Patent No. 5555718

  In the hot water device described in Patent Document 1, the consumption of the neutralizing agent is assumed by integrating the combustion amount per unit time and the calculated value based on the combustion time. Specifically, since the actual amount of combustion changes depending on the hot water supply amount, the set temperature of the hot water, the incoming water temperature, etc., the product of the actual combustion amount and the actual combustion time is the maximum combustion amount and the combustion time (maximum combustion time). (Quantity conversion time), and the maximum fuel amount conversion time is multiplied by a plurality of condition coefficients to calculate the life time corresponding conversion time. Then, when the life time corresponding conversion time reaches the life time, a predetermined notification is performed. Thus, in the hot water device described in Patent Document 1, in order to match the estimated consumption of the neutralizing agent with the actual consumption of the neutralizing agent, the combustion state is reflected. Thus, a plurality of conditional coefficients must be taken into account, and as a result, complicated arithmetic processing is required.

  Moreover, in a hot water apparatus, generally, heat exchange is performed between low-temperature heating in which heat is exchanged between the heat medium circulating in the low-temperature terminal and the combustion gas, and heat exchange between the heat medium circulating in the high-temperature terminal and the combustion gas. The hot water set temperature is different from that during high-temperature heating. Therefore, there is a difference in the amount of drain generated between the low temperature heating and the high temperature heating, and thus there is a difference in the consumption of the neutralizing agent. There is a need for a technique that can easily and accurately determine the arrival of the neutralizer life regardless of whether it is during low-temperature heating or high-temperature heating.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a hot water apparatus that can accurately determine the arrival of the neutralizer life with a simple configuration. That is.

  The hot water device according to the present invention can exchange heat between the heat medium circulating in the hot water terminal and the combustion gas. The hot water device includes a combustion device, a heat medium circulation circuit, a primary heat exchanger, a secondary heat exchanger, a neutralizer, a temperature sensor, and a control device. The combustion device is configured to generate combustion gases. The heat medium circulation circuit for circulating the heat medium includes a primary heat exchanger configured to recover the sensible heat of the combustion gas and a secondary heat exchanger configured to recover the latent heat of the combustion gas. And are connected. The neutralizer contains a neutralizing agent and is configured to neutralize the drain generated in the secondary heat exchanger. The heat medium circulation circuit is configured to heat the heat medium returned from the hot water terminal with the secondary heat exchanger, and then heat the heat medium with the primary heat exchanger and supply it to the hot water terminal. The temperature sensor is configured to detect the temperature of the heat medium output from the primary heat exchanger. The control device is configured to control the combustion device based on the detection value of the temperature sensor so that the temperature of the heat medium supplied to the hot water terminal becomes a set temperature. The control device further estimates the drain generation amount based on the detected value of the temperature sensor and the set temperature, and determines the life of the neutralizer using the estimated drain generation amount.

  According to the hot water device, the drain generation amount can be estimated easily and accurately by using the detection value and the set temperature of the temperature sensor used for controlling the combustion device for estimating the drain generation amount. Therefore, the arrival of the neutralizer life can be accurately determined with a simple configuration.

  Preferably, the hot water device further includes a measuring unit configured to measure a usage time of the hot water device. The control device executes correction for shortening the use time as the estimated drain generation amount decreases. The control device determines that the life of the neutralizer has reached when the cumulative usage time of the hot water device reaches the life of the neutralizer.

  If it does in this way, correction | amendment so that the accumulated usage time of a hot water apparatus will become short as the estimated drain generation amount decreases. In other words, correction is performed such that the lifetime of the neutralizer becomes longer as the amount of drain generation decreases. As a result, the arrival of the neutralizer life can be accurately determined.

  Preferably, the control device is configured to correct the usage time by multiplying the usage time measured by the measurement unit by a coefficient when the estimated drain generation amount is smaller than a reference amount. The coefficient is based on the ratio of the drain generation amount to the reference amount.

  In this way, it is possible to appropriately lengthen or shorten the accumulated use time of the hot water device depending on whether the amount of drain generation is large or small. That is, since the lifetime of the neutralizer can be appropriately lengthened or shortened according to the amount of drain generated, the arrival of the lifetime of the neutralizer can be accurately determined.

  Preferably, the control device estimates the drain generation amount based on the detection value of the temperature sensor and the set temperature by referring to the correlation between the detection value of the temperature sensor, the set temperature, and the drain generation amount that are obtained in advance. In this way, the drain generation amount can be estimated easily and accurately.

  Preferably, the control device estimates the drain generation amount by referring to a table indicating the correlation. In this way, the drain generation amount can be estimated easily and accurately.

  Preferably, the hot water device further includes an informing unit for informing that the life of the neutralizer has come. In this way, it is possible to alert the user to the necessity of maintenance such as replacement of the neutralizer and replenishment of the neutralizing agent at an appropriate time.

  Preferably, the hot water terminal includes a low temperature terminal and a high temperature terminal. The hot water device further includes a circulation pump disposed upstream of the heat medium circulation circuit relative to the primary heat exchanger, and a heat medium tank disposed upstream of the heat medium circulation circuit relative to the circulation pump. The heat medium circulation circuit includes a low-temperature forward circuit, a high-temperature forward circuit, and a bypass circuit. The low-temperature forward circuit heats the heat medium returned from the low-temperature terminal with a secondary heat exchanger and supplies the heat medium to the low-temperature terminal. The high-temperature forward circuit heats the heat medium returned from the high-temperature terminal with the secondary heat exchanger, then heats it with the primary heat exchanger and supplies it to the high-temperature terminal. The bypass circuit branches the high-temperature forward circuit and joins a part of the heat medium supplied to the high-temperature terminal to the heat medium circulation circuit upstream of the heat medium tank. The temperature sensor includes a high temperature thermistor configured to detect the temperature of the high temperature forward circuit.

  In this way, regardless of whether the hot water device is at high temperature heating or low temperature heating, the amount of drain generation is easily and accurately based on the detected value and set temperature of the high temperature thermistor used for controlling the combustion device. Can be estimated. Therefore, the arrival of the neutralizer life can be accurately determined with a simple configuration.

  According to the present invention, in the latent heat recovery type hot water apparatus, it is possible to accurately determine the arrival of the life of the neutralizer with a simple configuration.

It is the schematic which shows the structure of the hot water apparatus according to embodiment of this invention. It is a functional block diagram for demonstrating the structure of the control apparatus shown in FIG. It is a figure explaining the operation | movement at the time of the high temperature heating of the hot water apparatus according to this Embodiment. It is a figure explaining the operation | movement at the time of the low temperature heating of the hot water apparatus according to this Embodiment. It is a figure explaining the operation | movement at the time of the low temperature heating of the hot water apparatus according to this Embodiment. It is a figure explaining the operation | movement at the time of the low temperature heating of the hot water apparatus according to this Embodiment. It is a figure which shows the correlation of preset temperature, the detection value of a high temperature thermistor, and the amount of drain generation. It is a flowchart for demonstrating the procedure of the estimation process of a drain generation amount, and the lifetime determination process of a neutralizer.

  Embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic diagram showing a configuration of a hot water apparatus according to an embodiment of the present invention. The hot water device according to the present embodiment is configured to perform heat exchange between a heat medium (water) circulating through the hot water terminal and the combustion gas. The hot water terminal includes a high temperature terminal 20 and a low temperature terminal 21 (see FIG. 4). The high temperature terminal 20 is, for example, a bathroom heating device, and the low temperature terminal 21 is, for example, a floor heating device.

  Referring to FIG. 1, the hot water device includes a heat medium circulation circuit 1, a primary heat exchanger 2, a secondary heat exchanger 3, a circulation pump 4, a heat medium tank 5, and a burner (combustion device) 6. And a fan (blower device) 7, valves 8 and 9, a control device 10, a low temperature thermistor 11, and a high temperature thermistor 12.

  The heat medium circulation circuit 1 is for circulating the heat medium. The primary heat exchanger 2 and the secondary heat exchanger 3 are connected to the heat medium circulation circuit 1. The primary heat exchanger 2 and the secondary heat exchanger 3 exchange heat between the heat medium and the combustion gas. The primary heat exchanger 2 is configured to be able to absorb the sensible heat of the combustion gas, and the secondary heat exchanger 3 is configured to be able to absorb the latent heat of the combustion gas. The primary heat exchanger 2 and the secondary heat exchanger 3 are connected to each other. The primary heat exchanger 2 is located above the burner 6, and the secondary heat exchanger 3 is located above the primary heat exchanger 2.

  The circulation pump 4 circulates the heat medium in the heat medium circuit 1. The circulation pump 4 is disposed upstream of the heat medium circulation circuit 1 with respect to the primary heat exchanger 2. The heat medium tank 5 absorbs and relaxes the pressure increase accompanying the expansion or the contraction due to the expansion of the deposition due to the temperature change of the heat medium. The heat medium tank 5 is configured to be able to replenish the heat medium. The heat medium tank 5 is arranged on the upstream side of the heat medium circulation circuit 1 with respect to the circulation pump 4.

  The burner 6 generates combustion gas. The fan 7 supplies combustion air to the burner 6. The fan 7 is disposed below the burner 6. The valve 8 is configured to allow the flow of the heat medium from the low-temperature forward circuit 1a to the low-temperature terminal 21 (FIG. 4). The valve 9 is configured to allow the flow of the heat medium from the high-temperature forward circuit 1 b to the high-temperature terminal 20. The valve 8 is configured to be closed when a heat medium is flowing from the high-temperature forward circuit 1 b to the high-temperature terminal 20. The valve 9 is configured to be able to close when a heat medium is flowing from the low temperature going circuit 1a to the low temperature terminal 21.

  The low temperature thermistor 11 is connected to the heat medium tank 5. The low temperature thermistor 11 detects the temperature ThL of the low temperature going circuit 1 a and gives a signal indicating the detected value to the control device 10. The high temperature thermistor 12 is connected to the heat medium circulation circuit 1 on the downstream side of the primary heat exchanger 2. The high temperature thermistor 12 detects the temperature ThH of the high temperature forward circuit 1b and gives a signal indicating the detected value to the control device 10.

  The heat medium circulation circuit 1 includes a high-temperature forward circuit 1b, a low-temperature forward circuit 1a, and a bypass circuit 1c. The low-temperature going-out circuit 1 a is configured to heat the heat medium returned from the hot water terminals (the high temperature terminal 20 and the low temperature terminal 21) with the secondary heat exchanger 3 and supply the heat medium to the low temperature terminal 21. The high-temperature forward circuit 1 b is configured to heat the heat medium returned from the hot water terminal with the secondary heat exchanger 3, then heat it with the primary heat exchanger 2 and supply it to the high-temperature terminal 20. The bypass circuit 1 c is configured to branch from the high-temperature forward circuit 1 b and join a part of the heat medium supplied to the high-temperature terminal 20 to the heat medium circulation circuit 1 on the upstream side of the heat medium tank 5.

Next, the operation at the time of high-temperature heating of the hot water device according to the present embodiment will be described.
With reference to FIG. 1, the heat medium returned from the high-temperature terminal 20 flows into the secondary heat exchanger 3 through the heat medium circulation circuit 1 and is heated by the secondary heat exchanger 3. The temperature of the heat medium returned from the high temperature terminal 20 is, for example, 60 ° C., and the temperature of the heat medium after being heated by the secondary heat exchanger 3 is about 62 ° C. The heat medium heated in the secondary heat exchanger 3 flows into the heat medium tank 5 and then flows into the circulation pump 4 from the heat medium tank 5. Then, the circulation medium 4 flows out the heat medium, so that the heat medium flows into the primary heat exchanger 2. The heat medium heated by the primary heat exchanger 2 is supplied to the high temperature terminal 20 through the high temperature forward circuit 1b. The temperature of the heat medium supplied to the high temperature terminal 20 is 80 ° C., for example. That is, the detection value ThH of the high temperature thermistor 12 is 80 ° C. In this case, the temperature of the heat medium flowing into the bypass circuit 1c connected to the high-temperature going circuit 1b is also 80 ° C.

  Since the bypass circuit 1 c is connected to the heat medium tank 5, the high-temperature heat medium heated by the primary heat exchanger 2 flows into the heat medium tank 5. As a result, the temperature of the heat medium tank 5 becomes about 70 ° C.

  At the time of high-temperature heating, the control device 10 uses the burner 6 and the fan 7 so that the temperature of the heat medium supplied from the high-temperature forward circuit 1b to the high-temperature terminal 20 becomes the set temperature Ths based on the detection value ThH of the high-temperature thermistor 12. To control. In the example of FIG. 1, the case where the set temperature Ths is 80 ° C. is shown.

  During the heating operation, in the secondary heat exchanger 3, when the latent heat of the combustion gas is recovered, the water vapor in the combustion gas is cooled and condensed, so that drain which is strongly acidic condensed water is generated. The generated drain is neutralized by passing through the neutralizer 15 and discharged to the outside of the hot water apparatus.

  Specifically, as a configuration for neutralizing the drain, the hot water apparatus further includes a tray 13, a drain pipe 14, and a neutralizer 15. The tray 13 is disposed below the secondary heat exchanger 3 and is configured to collect the drain dripped from the secondary heat exchanger 3. The tray 13 is connected to the neutralizer 15 through the drain pipe 14. Therefore, the drain collected in the tray 13 is collected by the neutralizer 15 through the drain pipe 14.

  The neutralizer 15 neutralizes the collected drain. Specifically, the neutralizer 15 is filled with a known neutralizing agent 16 such as calcium carbonate. The drain is neutralized by contact with the neutralizing agent 16.

  Neutralizing agent 16 is consumed by neutralizing the drain. In order to maintain the neutralization performance of the drain, it is necessary to determine the life of the neutralizer 15 and perform maintenance such as replacement of the neutralizer 15 or replenishment of the neutralizer 16.

  Therefore, in the hot water apparatus according to the present embodiment, the life of the neutralizer 15 is determined using the method described below, and notification is made that the life of the neutralizer 15 has arrived. Thereby, the necessity of the maintenance of the neutralizer 15 can be alerted to the user.

FIG. 2 is a functional block diagram for explaining the configuration of the control device 10 shown in FIG.
Referring to FIG. 2, control device 10 is electrically connected to each of circulation pump 4, burner 6, fan 7, valves 8 and 9, low temperature thermistor 11, and high temperature thermistor 12. The control device 10 is further electrically connected to each of the setting unit 38 and the notification unit 40.

  The setting unit 38 provides the control unit 30 with a set temperature Ths in each of the high-temperature heating and the low-temperature heating of the hot water device. The set temperature Ths during high-temperature heating is, for example, 80 ° C. to 70 ° C., and the set temperature Ths during low-temperature heating is, for example, 60 ° C. to 50 ° C.

  The alerting | reporting part 40 is comprised so that the information regarding the driving | operation of a hot water apparatus may be alert | reported. The notification unit 40 is used to notify that the life of the neutralizer 15 has been reached in the life determination of the neutralizer 15 described later. At least one of the setting unit 38 and the notification unit 40 can be realized by, for example, a remote controller for remotely operating the hot water device.

  The control device 10 includes a control unit 30, a measurement unit 32, a determination unit 34, and a table 36. The control unit 30 controls the heating operation of the hot water apparatus based on the set temperature Ths, the detection value ThL of the low temperature thermistor 11, and the detection value ThH of the high temperature thermistor 12. Specifically, at the time of high-temperature heating, the control unit 30 closes the valve 8 and drives the circulation pump 4 to circulate the heat medium in the high-temperature going-out circuit 1b. The control unit 30 further controls the combustion heat amount of the burner 6 and the rotational speed of the fan 7 so that the temperature ThH of the high-temperature going-out circuit 1b detected by the high-temperature thermistor 12 becomes the set temperature Ths.

  During low temperature heating, the valve 9 is closed and the circulation pump 4 is driven to circulate the heat medium in the low temperature going circuit 1a. The control unit 30 further controls the combustion heat amount of the burner 6 and the rotational speed of the fan 7 so that the temperature ThL of the low-temperature forward circuit 1a detected by the low-temperature thermistor 11 becomes the set temperature Ths.

  The measuring unit 32 measures the usage time of the hot water device. The usage time of the hot water device corresponds to the heating operation time of the hot water device, and substantially corresponds to the combustion time of the burner 6. The measurement unit 32 gives the measurement result of the usage time to the determination unit 34.

  The determination unit 34 calculates the cumulative usage time of the hot water device by integrating the usage time measured by the measurement unit 32. The accumulated usage time is set to 0 in the initial state such as at the time of shipment. The accumulated use time is reset to 0 when maintenance such as replacement of the neutralizer 15 or replenishment of the neutralizing agent 16 is performed and a reset switch (not shown) provided in the hot water device is pressed. The accumulated usage time can be stored in a memory (not shown) in the control device 10.

  The determination unit 34 determines the life of the neutralizer 15 based on the set temperature Ths, the detected value ThH of the high temperature thermistor 12, and the accumulated usage time of the hot water device. Specifically, the determination unit 34 estimates the amount of drain generation in the secondary heat exchanger 3 based on the set temperature Ths and the detection value ThH of the high temperature thermistor 12. And the determination part 34 determines the lifetime of the neutralizer 15 using the estimated drain generation amount.

(Drain generation estimation process)
Initially, the process which estimates the drain generation amount in the secondary heat exchanger 3 is demonstrated.

  FIG. 3 is a diagram for explaining the operation during high-temperature heating of the hot water device according to the present embodiment, and is a diagram contrasted with FIG. Referring to FIG. 3, the set temperature Ths is the same as in FIG. 1 (Ths = 80 ° C.), but the temperature of the heat medium returned from the high temperature terminal 20 and the temperature of the heat medium supplied to the high temperature terminal 20 Is different.

  In FIG. 3, the temperature of the heat medium returned from the high temperature terminal 20 is, for example, 30 ° C., and the temperature of the heat medium supplied to the high temperature terminal 20 is, for example, 50 ° C. That is, the detection value ThH of the high temperature thermistor 12 is 50 ° C.

  Moreover, when the heat medium heated by the primary heat exchanger 2 flows into the heat medium tank 5, the temperature of the heat medium tank 5 becomes about 40 ° C.

  Here, when the amount of drain generated in the secondary heat exchanger 3 is compared between FIG. 1 and FIG. 3, the drain generation amount (unit: drain generation amount per minute) in FIG. 1 is D1. In contrast, the amount of drain generation in FIG. 3 is D2, which is greater than D1. D1 is about 10 cc / min and D2 is about 20 cc / min. This drain generation amount will be considered by paying attention to the set temperature Ths and the detection value ThH of the high temperature thermistor 12.

  In the secondary heat exchanger 3, the latent heat in the exhaust of the primary heat exchanger 2 is recovered to the heat medium returned from the high temperature terminal 20. At that time, drain is generated on the surface of the secondary heat exchanger 3. When the exhaust temperature of the primary heat exchanger 2 is higher than the temperature of the heat medium of the secondary heat exchanger 3, heat is generated in the secondary heat exchanger 3, so that the latent heat in the exhaust of the primary heat exchanger 2 is Collected and drain is produced.

  Further, when the exhaust temperature of the primary heat exchanger 2 is higher than the heat medium temperature of the secondary heat exchanger 3, the difference between the heat medium temperature of the secondary heat exchanger 3 and the exhaust temperature of the primary heat exchanger 2. It is considered that the larger the is, the more latent heat is recovered by the secondary heat exchanger 3, and therefore the amount of drain generation increases.

  Here, the heat medium temperature of the secondary heat exchanger 3 depends on the temperature of the heat medium returned from the high temperature terminal 20. On the other hand, the exhaust temperature of the primary heat exchanger 2 depends on the amount of combustion heat of the burner 6. The amount of fuel burned by the burner 6 is represented by the sum of the feedforward heat amount according to the set temperature Ths and the feedback heat amount according to the deviation of the detected value ThH of the high temperature thermistor 12 from the set temperature Ths.

  In FIG. 1, since the set temperature Ths and the detected value ThH of the high temperature thermistor 12 are almost equal, the deviation of the detected value ThH from the set temperature Ths is almost zero. Therefore, in the control of the combustion heat quantity of the burner 6, the feedback heat quantity is reduced. As a result, the amount of combustion heat of the burner 6 decreases, and the exhaust temperature of the primary heat exchanger 2 tends to decrease. On the other hand, since the heat medium temperature of the secondary heat exchanger 3 is as high as 60 ° C., the difference between the heat medium temperature of the secondary heat exchanger 3 and the exhaust temperature of the primary heat exchanger 2 tends to be small. As a result, it is considered that the amount of drain generation tends to decrease.

  On the other hand, in FIG. 3, since the set temperature Ths is higher than the detected value ThH of the high temperature thermistor 12, the deviation of the detected value ThH from the set temperature Ths is larger than that in FIG. Therefore, in the control of the combustion heat quantity of the burner 6, the feedback heat quantity is increased, so that the combustion heat quantity of the burner 6 tends to increase. On the other hand, the heat medium temperature of the secondary heat exchanger 3 is 30 ° C., which is lower than the heat medium temperature of the secondary heat exchanger 3 of FIG. As a result, the difference between the heat medium temperature of the secondary heat exchanger 3 and the exhaust temperature of the primary heat exchanger 2 tends to increase. As a result, it is considered that the amount of drain generated is larger than that in FIG.

  Next, the operation | movement at the time of the low temperature heating of the hot water apparatus according to this Embodiment and the amount of drain generations are demonstrated using FIGS.

  With reference to FIG. 4, the heat medium returned from the low temperature terminal 21 flows into the secondary heat exchanger 3 through the heat medium circulation circuit 1 and is heated by the secondary heat exchanger 3. At the time of low temperature heating, the temperature of the heat medium returned from the low temperature terminal 21 is, for example, 40 ° C., and the heat medium after being heated by the secondary heat exchanger 3 is, for example, about 42 ° C. The heat medium heated by the secondary heat exchanger 3 flows into the heat medium tank 5. In addition, the heat medium flowing from the bypass circuit 1 c into the heat medium circulation circuit 1 on the upstream side of the heat medium tank 5 also flows into the heat medium tank 5. The temperature of the heat medium flowing through the bypass circuit 1c is 80 ° C., for example. That is, the detection value ThH of the high temperature thermistor 12 is 80 ° C.

  As a result, the temperature of the heat medium in the heat medium tank 5 is 60 ° C., for example. That is, the detection value ThL of the low temperature thermistor 11 is 60 ° C. Then, the circulating pump 4 sends out the heat medium, so that the heat medium is supplied to the low temperature terminal 21 through the low temperature going circuit 1a. The temperature of the heat medium supplied to the low temperature terminal 21 is, for example, 60 ° C. The drain generation amount in FIG. 4 is D2 (about 20 cc / min).

  Referring to FIG. 5, the set temperature Ths, the temperature of the heat medium returned from the low temperature terminal 21, and the temperature of the heat medium supplied to the low temperature terminal 21 are different from those in FIG. 4.

  In the hot water device, an operation (so-called hot dash operation) is performed in which a heating medium having a temperature higher than normal is supplied for a certain time from the start of operation to quickly warm the hot water terminal. In FIG. 5, the set temperature Ths during the hot dash operation is set to 80 ° C. In the hot dash operation, the control unit 30 controls the combustion heat amount of the burner 6 and the rotation speed of the fan 7 so that the detection value ThH of the high temperature thermistor 12 becomes the set temperature 80 ° C.

  In FIG. 5, the temperature of the heating medium returned from the low temperature terminal 21 is, for example, 30 ° C., and the heating medium after being heated by the secondary heat exchanger 3 is, for example, about 32 ° C. The temperature of the heat medium flowing through the bypass circuit 1c is 60 ° C., for example. That is, the detection value ThH of the high temperature thermistor 12 is 60 ° C. As a result, the temperature of the heat medium in the heat medium tank 5 is, for example, 50 ° C. That is, the detection value ThL of the low temperature thermistor 11 is 50 ° C. The temperature of the heat medium supplied to the low temperature terminal 21 is also 50 ° C. The drain generation amount in FIG. 5 is D2 (about 20 cc / min).

  Referring to FIG. 6, the set temperature Ths, the temperature of the heat medium returned from the low temperature terminal 21, and the temperature of the heat medium supplied to the low temperature terminal 21 are different from those in FIGS. 4 and 5.

  In FIG. 6, the set temperature Ths is 35 ° C. The temperature of the heat medium returned from the low temperature terminal 21 is, for example, 16 ° C., and the heat medium after being heated by the secondary heat exchanger 3 is, for example, about 18 ° C. The temperature of the heat medium flowing through the bypass circuit 1c is, for example, 80 ° C. That is, the detection value ThH of the high temperature thermistor 12 is 80 ° C. As a result, the temperature of the heat medium in the heat medium tank 5 becomes 35 ° C., for example. That is, the detection value ThL of the low temperature thermistor 11 is 35 ° C. The temperature of the heat medium supplied to the low temperature terminal 21 is also 35 ° C. The drain generation amount in FIG. 6 is D3 which is larger than D2. D3 is about 30 cc / min.

  Here, comparing the amount of drain generated in the secondary heat exchanger 3 with respect to FIGS. 4 to 6, the amount of drain generated in FIGS. 4 and 5 is D2 (about 20 cc / min). The drain generation amount at 6 is D3 (about 30 cc / min), which is larger than D2. As in the case of high-temperature heating, the amount of drain generation will be considered by paying attention to the set temperature Ths and the detected value ThH of the high-temperature thermistor 12 during low-temperature heating.

  In FIG. 4, the detection value ThL of the low temperature thermistor 11 corresponds to the temperature of the heat medium flowing into the primary heat exchanger 2, and the set temperature Ths corresponds to the target temperature of the temperature of the heat medium flowing into the primary heat exchanger 2. . The detected value ThH of the high temperature thermistor 12 corresponds to the temperature of the heat medium heated by the primary heat exchanger 2 and flowing into the heat medium tank 5 through the bypass circuit 1c.

  At the time of low temperature heating, the control unit 30 controls the amount of combustion heat of the burner 6 so that the detection value ThL of the low temperature thermistor 11 becomes the set temperature Ths. That is, the combustion heat amount of the burner 6 is controlled in accordance with the temperature deviation of the heat medium flowing into the primary heat exchanger 2 with respect to the set temperature Ths, and the temperature of the heat medium heated by this combustion heat amount is detected by the high temperature thermistor 12. The

  In FIG. 4, since the set temperature Ths is lower than that in FIG. 1, the heat medium temperature of the secondary heat exchanger 3 is lower than that in FIG. Further, the detection value ThH of the high temperature thermistor 12 is higher than the set temperature Ths by controlling the combustion heat quantity of the burner 6. In addition, since the deviation of the detected value ThL of the low temperature thermistor 11 with respect to the set temperature Ths increases as the heat medium temperature of the secondary heat exchanger 3 decreases, the amount of combustion heat increases. As a result, the detection value ThH of the high temperature thermistor 12 is considered to be high.

  Therefore, in FIG. 4, since the heat medium temperature of the secondary heat exchanger 3 is lower and the exhaust temperature of the primary heat exchanger 2 is higher than in FIG. 1, the heat medium temperature of the secondary heat exchanger 3 The difference from the exhaust temperature of the primary heat exchanger 2 tends to increase. Thereby, in FIG. 4, it is thought that the drain generation amount tends to be larger than that in FIG.

  On the other hand, in FIG. 5, since it is a hot dash operation, the combustion heat amount (feedback heat amount) of the burner 6 is controlled according to the deviation of the detected value ThH of the high temperature thermistor 12 from the set temperature Ths. In FIG. 5, since the set temperature Ths is higher than the detection value ThH of the high temperature thermistor 12, the amount of combustion heat of the burner 6 tends to increase by increasing the amount of feedback heat. On the other hand, the heat medium temperature of the secondary heat exchanger 3 is as low as 30 ° C. As a result, similarly to FIG. 4, the difference between the heat medium temperature of the secondary heat exchanger 3 and the exhaust temperature of the primary heat exchanger 2 tends to be larger than that in FIG. It is thought that.

  In FIG. 6, since the set temperature Ths is lower than that in FIG. 4, the heat medium temperature of the secondary heat exchanger 3 is lower than that in FIG. 4. Thereby, the temperature of the heat medium flowing into the primary heat exchanger 2 is also lowered. On the other hand, in FIG. 6 and FIG. 4, since the detection value ThH of the high temperature thermistor 12 is equal, it is considered that the amount of combustion heat of the burner 6 in FIG. 6 is larger than the amount of combustion heat of the burner 6 in FIG. Therefore, in FIG. 6, it is considered that the exhaust temperature of the primary heat exchanger 2 is higher than that in FIG. As a result, in FIG. 6, since the heat medium temperature of the secondary heat exchanger 3 is lower and the exhaust temperature of the primary heat exchanger 2 is higher than in FIG. 4, the heat medium temperature of the secondary heat exchanger 3. And the difference between the exhaust temperature of the primary heat exchanger 2 tends to increase. Therefore, it is considered that the amount of drain generation tends to be larger than that in FIG.

  The inventor evaluated whether there is a correlation between the set temperature Ths and the detected value ThH of the high temperature thermistor 12 and the amount of generated drain for each of high temperature heating and low temperature heating. The result of examining the correlation is shown in FIG.

  FIG. 7 shows the relationship between the set temperature Ths, the detection value ThH of the high temperature thermistor 12, and the amount of drain generation. FIG. 7 includes the drain generation amount during high-temperature heating shown in FIGS. 1 and 3 and the drain generation amount during low-temperature heating shown in FIGS. 4 to 6.

  As shown in FIG. 7, the drain generation amount is D1 when the set temperature Ths and the detection value ThH of the high temperature thermistor 12 are both high during both high temperature heating and low temperature heating. On the other hand, when the detection value ThH of the high temperature thermistor 12 was low, the drain generation amount tended to increase from D1. Moreover, when set temperature Ths became low, the tendency for the drain generation amount to increase from D1 was seen.

  When both the set temperature Ths and the detected value ThH of the high temperature thermistor 12 are high, the heat medium temperature of the secondary heat exchanger 3 is relatively high and the primary heat exchanger 2 Since the exhaust temperature tends to decrease, it is considered that the difference between the heat medium temperature of the secondary heat exchanger 3 and the exhaust temperature of the primary heat exchanger 2 is reduced, and as a result, the amount of drain generation is reduced.

  On the other hand, when the detected value ThH of the high temperature thermistor 12 is low, the exhaust heat temperature of the primary heat exchanger 2 tends to increase due to the increase in the amount of combustion heat of the burner 6, and therefore the heat medium temperature of the secondary heat exchanger 3 It is considered that the difference from the exhaust temperature of the primary heat exchanger 2 increases, and as a result, the amount of drain generation increases.

  Further, when the set temperature Ths is lowered, the heat medium temperature of the secondary heat exchanger 3 is also lowered, so that the amount of combustion heat of the burner 6 is increased, and as a result, the exhaust temperature of the primary heat exchanger 2 tends to rise. As a result, it is considered that the difference between the heat medium temperature of the secondary heat exchanger 3 and the exhaust temperature of the primary heat exchanger 2 increases, resulting in an increase in the amount of drain generation.

  The determination unit 34 refers to the correlation shown in FIG. 7 at each of the high temperature heating time and the low temperature heating time, and based on the set temperature Ths and the detection value ThH of the high temperature thermistor 12, Estimate the amount of drain generated. Specifically, the control device 10 has a table 36 (see FIG. 2) showing the correlation of FIG. The table 36 can be stored in advance in a memory (not shown). The determination unit 34 can estimate the drain generation amount based on the set temperature Ths and the detection value ThH of the high temperature thermistor 12 by referring to the table 36.

  Thus, according to the hot water device according to the present embodiment, by using the detected value ThH and the set temperature Ths of the high temperature thermistor 12 used for controlling the combustion heat amount of the burner 6 for estimating the drain generation amount, Can be estimated easily and accurately. Further, whether the hot water apparatus is at high temperature heating or low temperature heating, the drain generation amount can be accurately estimated with reference to the correlation shown in FIG. As a result, the drain generation amount can be accurately estimated with a simple configuration.

(Neutralizer life judgment process)
Next, a process for determining the lifetime of the neutralizer 15 using the drain generation amount estimated by the drain generation amount estimation process will be described.

  As shown in FIG. 2, the measurement unit 32 measures the usage time of the hot water device and gives the measurement result to the determination unit 34. The usage time of the hot water device corresponds to the heating operation time of the hot water device, and substantially corresponds to the combustion time of the burner 6.

  The determination unit 34 corrects the usage time measured by the measurement unit 32 using the estimated drain generation amount. The determination unit 34 performs correction to shorten the use time as the drain generation amount decreases.

  Specifically, the determination unit 34 uses the maximum drain generation amount D3 in the correlation shown in FIG. 7 as a reference amount, and when the estimated drain generation amount is smaller than the reference amount, a coefficient for correcting the use time Set k. This coefficient k is based on the ratio of the estimated drain generation amount to the reference amount (maximum drain generation amount D3). That is, when the estimated drain generation amount is De, the coefficient k is given by the equation (1).

k = De / D3 (1)
The determination unit 34 corrects the usage time by multiplying the usage time measured by the measurement unit 32 by the coefficient k. When the usage time measured by the measuring unit 32 is Tu and the corrected usage time is Tu #, the corrected usage time Tu # is calculated by the equation (2).

Tu # = k × Tu (2)
According to the above equation (2), when the estimated drain generation amount is D1, the usage time Tu # is shortened to D1 / D3 of the actual usage time Tu. Further, when the estimated drain generation amount is D2, the use time Tu # is shortened to D2 / D3 of the actual use time Tu. That is, the use time Tu # becomes shorter as the drain generation amount decreases.

  The determination unit 34 updates the accumulated use time by adding the corrected use time Tu # to the accumulated use time (value before the use time Tu elapses) stored in the memory in the control device 10. . When the accumulated usage time is Tau, Tau is updated to Tau + Tu # when the usage time Tu elapses. The updated accumulated usage time Tau is stored in the memory.

  The determination unit 34 determines whether or not the accumulated usage time Tau stored in the memory has reached the lifetime TL of the neutralizer 15. The lifetime TL of the neutralizer 15 is set to a time until the neutralizer 16 in the neutralizer 15 is consumed when the drain generation amount is the reference amount (maximum drain generation amount D3). . In other words, assuming that the hot water device is used under the condition that the drain generation amount becomes the reference amount, and the hot water device is used over the lifetime under this condition, The neutralizer 15 is filled in the neutralizer 15.

  When the cumulative usage time Tau reaches the lifetime TL of the neutralizer 15, the determination unit 34 uses the notification unit 40 to notify that the lifetime of the neutralizer 15 has arrived. Note that the determination unit 34 may make a notification to alert the user when the accumulated usage time Tau approaches the lifetime TL of the neutralizer 15.

  Further, when the cumulative usage time Tau has exceeded the life time TL for a certain time, the determination unit 34 issues a warning from the notification unit 40 and forcibly stops the hot water device.

  When maintenance such as replacement of the neutralizer 15 or replenishment of the neutralizing agent 16 is performed and a reset switch (not shown) provided in the hot water device is pressed, the determination unit 34 notifies the notification unit 40 of the notification. And the accumulated use time Tau stored in the memory is returned to zero.

  As described above, the determination unit 34 estimates the drain generation amount based on the set temperature Ths and the detection value ThH of the high temperature thermistor 12, and shortens the use time Tu of the hot water device as the estimated drain generation amount decreases. Make corrections. According to this, as the drain generation amount decreases, the cumulative use time Tau becomes shorter. In other words, the lifetime TL of the neutralizer 15 becomes longer as the drain generation amount decreases. Thereby, the arrival of the life of the neutralizer 15 can be accurately determined.

  The drain generation amount estimation process and the neutralizer life determination process described above can be summarized in a flowchart as shown in FIG. The flowchart of FIG. 8 can be executed by the control device 10.

  Referring to FIG. 8, control device 10 determines whether or not the hot water device is in a heating operation in step S01. When the hot water device is in the operation stop state (NO in S01), control device 10 skips the subsequent steps and ends the process.

  On the other hand, when the hot water device is in the heating operation (YES in S01), control device 10 acquires set temperature Ths in step S02. The control device 10 further acquires the detection value ThH of the high temperature thermistor 12 in step S03.

  The control device 10 estimates the drain generation amount based on the set temperature Ths and the detected value ThH of the high temperature thermistor 12 in step S05 when the table 36 showing the correlation in FIG. 7 is referred in step S04.

  The control device 10 proceeds to step S06, and corrects the usage time Tu measured by the measuring unit 32 using the drain generation amount estimated in step S05. Specifically, the control device 10 calculates the coefficient k by substituting the estimated drain generation amount into the equation (1). Then, using the calculated coefficient k, the usage time Tu is corrected by the equation (2).

  In step S07, control device 10 updates accumulated use time Tau by adding corrected use time Tu # to accumulated use time Tau.

  The control device 10 compares the accumulated use time Tau with the lifetime TL of the neutralizer 15 in step S08. If Tau ≧ TL (YES in S08), control device 10 determines that the life of neutralizer 15 has come. In step S09, the control device 10 uses the notification unit 40 (FIG. 2) to notify that the life of the neutralizer 15 has been reached. On the other hand, if Tau <TL (NO in S08), control device 10 ends the process.

  In the hot water device according to the above-described embodiment, a configuration in which the correction of the use time Tu of the hot water device and the setting of the lifetime TL of the neutralizer 15 are performed using the maximum drain generation amount D3 in the correlation of FIG. 7 as a reference amount. However, the minimum drain generation amount D1 or D2 in the correlation of FIG. 7 may be used as a reference amount.

  For example, when the minimum drain generation amount D1 is used as a reference amount, the coefficient k for correcting the use time Tu is De / D1. Accordingly, correction is made to increase the use time Tu as the estimated drain generation amount De increases. Also in this case, the cumulative use time Tau becomes shorter as the drain generation amount decreases. Therefore, since the cumulative use time Tau can be lengthened or shortened according to the drain generation amount, the arrival of the life of the neutralizer 15 can be accurately determined.

  The drain generation amount estimation process and the neutralizer life determination process described above can also be applied to commercial hot water apparatuses used in public baths, hotels, restaurants, and the like. That is, in the commercial hot water apparatus, the amount of drain generation can be estimated based on the set temperature Ths and the detection value ThH of the high temperature thermistor 12 by referring to the correlation shown in FIG. The life of the neutralizer 15 can be determined using the amount of drain generated.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Heat medium circulation circuit, 2 Primary heat exchanger, 3 Secondary heat exchanger, 4 Circulation pump, 5 Heat medium tank, 6 Burner, 7 Fan, 8, 9 Valve, 10 Control device, 11 Low temperature thermistor, 12 High temperature thermistor , 15 Neutralizer, 16 Neutralizer, 20 High temperature terminal, 21 Low temperature terminal, 30 Control unit, 32 Measurement unit, 34 Determination unit, 36 Table, 38 Setting unit, 40 Notification unit.

Claims (7)

A hot water device capable of exchanging heat between the heat medium circulating in the hot water terminal and the combustion gas,
A combustion device configured to generate the combustion gas;
A heating medium circulation circuit for circulating the heating medium;
A primary heat exchanger connected to the heating medium circulation circuit and configured to recover sensible heat of the combustion gas;
A secondary heat exchanger connected to the heating medium circulation circuit and configured to recover latent heat of the combustion gas;
A neutralizer containing a neutralizer and configured to neutralize drain generated in the secondary heat exchanger,
The heating medium circulation circuit is configured to heat the heating medium returned from the hot water terminal with the secondary heat exchanger and then supply the heated water terminal with the primary heat exchanger,
The hot water device is
A temperature sensor for detecting the temperature of the heat medium output from the primary heat exchanger;
A control device configured to control the combustion device based on a detection value of the temperature sensor so that a temperature of the heating medium supplied to the hot water terminal becomes a set temperature;
The controller further estimates a drain generation amount based on a detection value of the temperature sensor and the set temperature, and determines a lifetime of the neutralizer using the estimated drain generation amount. A measuring unit configured to measure the usage time of the hot water device;
The control device includes:
Performing a correction to shorten the use time as the estimated drain generation amount decreases,
The hot water device according to claim 1, wherein when the cumulative usage time of the hot water device reaches the life time of the neutralizer, it is determined that the life of the neutralizer has come. The control device is configured to correct the use time by multiplying the use time measured by the measurement unit by a coefficient when the estimated drain generation amount is smaller than a reference amount.
The hot water device according to claim 2, wherein the coefficient is based on a ratio of the drain generation amount to the reference amount.   The control device determines the drain generation amount based on the detection value of the temperature sensor and the set temperature by referring to the correlation between the detection value of the temperature sensor, the set temperature, and the drain generation amount that are obtained in advance. The hot water device according to any one of claims 1 to 3, which is estimated.   The hot water device according to claim 4, wherein the control device estimates the drain generation amount by referring to a table indicating the correlation.   The hot water device according to any one of claims 1 to 5, further comprising a notifying unit for notifying that the life of the neutralizer has come. The hot water terminal includes a low temperature terminal and a high temperature terminal,
The hot water device is
A circulation pump arranged on the upstream side of the heat medium circulation circuit from the primary heat exchanger;
A heating medium tank disposed further upstream of the circulation pump than the circulation pump,
The heating medium circulation circuit is
A low-temperature circuit that heats the heat medium returned from the low-temperature terminal by the secondary heat exchanger and supplies the heat medium to the low-temperature terminal;
A high-temperature forward circuit that heats the heat medium returned from the high-temperature terminal by the secondary heat exchanger and then supplies the heat medium to the high-temperature terminal by heating with the primary heat exchanger;
A bypass circuit that branches the high-temperature forward circuit and joins a part of the heat medium supplied to the high-temperature terminal to the heat medium circulation circuit upstream of the heat medium tank;
The hot water device according to claim 1, wherein the temperature sensor includes a high temperature thermistor configured to detect a temperature of the high temperature going circuit.

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