JP2013088065A - Liquid heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid heater capable of preventing a user from feeling inconvenient while securing an energy saving property.SOLUTION: A controller 50 for a water heater S, which is one embodiment of the liquid heater, includes a storage part 52 for storing a liquid supply temperature setting value which is set within a prescribed period by an operation of an operation terminal 40 and is used as a temperature at which a liquid is supplied to the outside, and a control part 51 for calculating a first temporary target boiling temperature on the basis of a parameter, calculating a second temporary target boiling temperature on the basis of the liquid supply temperature setting value within the prescribed period, and controlling a heat pump unit 20 so as to heat hot water with the higher one of the first temporary target boiling temperature and the second temporary target boiling temperature as a target boiling temperature.

Description

  The present invention relates to a liquid heating apparatus such as a water heater.

  In the conventional boiling water storage type electric water heater, the boiling control calculates the required amount of heat per day based on the past use results of the user and determines the target boiling temperature to minimize the power consumption in order to improve energy saving. Boiling control is performed (see Patent Documents 1 and 2).

JP 2011-145001 A JP 2011-144959 A

  However, there is an idea that the boiling temperature should be set high in order to ensure a sufficient amount for the user's required amount of hot water. For the user, it is most inconvenient to run out of hot water during the daytime (while using hot water supply), so the amount of boiling at night should be set with a margin.

  On the other hand, for users who consume a small amount of hot water every day, the target boiling temperature of the water heater decreases due to the learning function provided in the water heater. In this case, when a situation occurs in which the total heat amount load is low but the instantaneous temperature load is high, such as a request for hot water supply higher than the hot water temperature in the hot water storage tank, a phenomenon in which the hot water temperature required by the user cannot be satisfied May occur. In recent years, electric water heaters tend to increase the flow rate of hot water, and the instantaneous heat load (temperature load) increases, so this phenomenon is likely to occur, and the hot water temperature in the tank is within a range where energy savings can be secured. It is desirable to be high.

  Then, this invention makes it a subject to provide the liquid heating apparatus which can make a user not feel inconvenience, ensuring energy saving property.

  In order to solve the above problems, the present invention is capable of communicating with a liquid heating unit that heats a liquid, a tank that stores the heated liquid, a control device that controls the liquid heating unit, and the control device. A liquid heating device comprising a connected operation terminal and sensors for detecting parameters for heating the liquid, wherein the control device is set within a predetermined period by operation of the operation terminal; A storage unit that stores a liquid supply temperature setting value that is a temperature for supplying the liquid to the outside, calculates a first target boiling temperature based on the parameter, and sets the liquid supply temperature setting value within a predetermined period. Based on the second target boiling temperature, and the liquid heating unit heats the liquid with the higher of the first target boiling temperature and the second target boiling temperature as the target boiling temperature. Characterized in that it comprises a control unit for controlling.

  According to the present invention, it is possible to prevent the user from feeling inconvenience while ensuring energy saving.

It is a lineblock diagram showing an example of a water heater concerning an embodiment of the present invention. It is a block diagram which shows the control apparatus and operation terminal of a water heater which concern on embodiment of this invention. It is a figure which shows the external appearance of the operating terminal which concerns on embodiment of this invention. It is a flowchart for demonstrating the operation example of the control apparatus of the water heater which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking as an example the case where the liquid heating apparatus of the present invention is applied to a hot water heater.

  As shown in FIG. 1, a water heater (liquid heating device) S according to an embodiment of the present invention is an electric water heater, and a tank unit 10 having a hot water storage tank 11 as a heating liquid supply unit, a heat pump unit 20, and . In addition, in the following description, the description regarding the valve | bulb (electromagnetic valve) etc. which were provided in each piping 14a-14h is abbreviate | omitted.

<Tank unit 10>
The tank unit 10 includes a hot water storage tank 11, a pump 12, and a hot water supply heat exchanger 13. The hot water storage tank 11 and the hot water supply heat exchanger 13 are connected to each other by a pipe 14e and a pipe 14f so as to allow liquid circulation.

  The hot water storage tank 11 is a tank for storing hot water. Water (liquid) is supplied to the lower part of the hot water storage tank 11 through the pipes 14a and 14b in sequence.

  The pump 12 is a pump that circulates the hot water in the hot water storage tank 11 through the pipe 14 e → the hot water supply heat exchanger 13 → the pipe 14 f → the hot water storage tank 11.

  The heat exchanger 13 is supplied from the pipes 14a and 14g by exchanging heat between the hot water supplied from the upper part of the hot water storage tank 11 via the pipe 14e and the water supplied sequentially via the pipes 14a and 14g. The generated water is heated to produce hot water. The hot water supplied from the hot water storage tank 11 is cooled by heat exchange and returned to the lower part of the hot water storage tank 11 via the pipe 14f. Further, the generated hot water is supplied to the outside (a bath, a mixing stopper, etc.) via the pipe 14h.

<Heat pump unit 20>
The heat pump unit 20 is a liquid heating unit for heating water (liquid) to be stored in the hot water storage tank 11, that is, a heat source. The heat pump unit 20 absorbs heat from the outside with a refrigerant such as expanded low-temperature carbon dioxide, and then performs heat exchange between the refrigerant that has been compressed and made hot and the low-temperature water from the hot water storage tank 11 that flows through the pipe 14c. It is a device that heats low-temperature water. The heat pump unit 20 repeatedly expands and compresses the refrigerant, absorbs heat from the outside and heats the low-temperature water, and a circulation pump (not shown) that circulates the low-temperature water in the hot water storage tank 11 flowing through the pipe 14c. And.

  The heat pump includes a compressor that compresses the refrigerant, a gas cooler (not shown) that heats the low-temperature water by exchanging heat between the compressed high-temperature refrigerant and the low-temperature water from the hot water storage tank 11, and expands the refrigerant. An expansion valve for reducing pressure, and a heat absorber for absorbing heat of the outside air to the refrigerant whose pressure has been reduced and whose temperature has been reduced are provided. The circulation pump pumps the low-temperature water in the hot water storage tank 11 through a pipe 14c connected to the lower part of the hot water storage tank 11, passes through the gas cooler of the heat pump and heats it, and then heats the hot water heated to high temperature through the pipe 14d. It is returned to the upper part of the hot water storage tank 11.

As described above, in the hot water heater S in recent years, in order to increase the hot water flow rate, the hot water in the hot water storage tank 11 is not directly discharged to the faucet, but the hot water and the water in the hot water storage tank 11 by the hot water supply heat exchanger 13. Some systems employ heat exchange with water and take out heated tap water. With this configuration, it is possible to increase the hot water supply pressure and keep the hot water flow rate high. In such a water heater S, when the flow rate of hot water is large, the heat exchange capacity is likely to decrease, and the required temperature for hot water supply may not be ensured. In general, since the temperature of the hot water produced by the water heater S is lowered before the hot water is discharged from the faucet outlet, the water heater S is hotter than the hot water temperature (hot water temperature setting value) required by the user. You have to prepare hot water.
In view of such circumstances, the water heater S according to the present embodiment can set a suitable target boiling temperature.

<Sensors 31-33>
The water heater S includes a water temperature sensor 31, a hot water temperature sensor 32 (32 a to 32 f), and a hot water supply flow rate sensor 33.
The water temperature sensor 31 is a sensor that detects the temperature (water temperature) of the water flowing through the pipe 14a.
The hot water temperature sensor 32 (32a to 32f) is a sensor that detects the temperature (hot water temperature) of the hot water stored in the hot water storage tank 11 at a predetermined location.
The hot water supply flow rate sensor 33 is a sensor that detects the flow rate of hot water flowing through the pipe 14h.

<Operation terminal 40>
As shown in FIG. 2, the operation terminal 40 is a remote controller installed in a bathroom, kitchen, or the like, and includes a control unit 41, an operation unit 42 (see FIG. 3) including various buttons, and a display unit 43 (including a display). 3). Based on the operation of the operation unit 42 by the user, the control unit 41 transmits a hot water supply temperature setting value, a bath temperature setting value, a water level setting value, etc. to the control device 50, or a hot water supply temperature setting value, a bath temperature setting value, a water level. A set value or the like is displayed on the display unit 43. For example, the user can set the hot water supply temperature setting value, which is the temperature at which hot water is supplied to the outside, to be set higher or lower by pressing the hot water supply temperature set value increase button 42a and the hot water supply temperature decrease button 42b. .

<Control device 50>
The control device 50 includes a control unit 51 and a storage unit 52.
The control unit 51 includes, as function units, a hot water supply temperature set value management unit 51a, a first temporary target boiling temperature calculation unit 51b, a second temporary target boiling temperature calculation unit 51c, and a target boiling temperature determination unit. 51d, a heat pump unit controller 51e, and a pump unit controller 51f.

  The hot water supply temperature set value management unit 51a manages the history of the hot water supply temperature set value within a predetermined period, acquires the hot water supply temperature set value transmitted from the operation terminal 40, and uses the acquired hot water supply temperature set value. While outputting to the pump control part 51f, the hot water supply temperature setting value within a predetermined period (for example, the latest three days) is stored in the storage part 52. The hot water supply temperature set value management unit 51 a stores the hot water supply temperature set value at that time in the storage unit 52 only when the flow rate is detected by the hot water supply flow rate sensor 53.

  The first temporary target boiling temperature calculation unit 51b acquires the detection results of the water temperature sensor 31 and the hot water temperature sensor 32 and the accumulated operation time of the heat pump unit 20 measured by the heat pump unit control unit 51e described later, Based on the water temperature, the hot water temperature, and the accumulated operation time of the heat pump unit 20 that are the acquired detection results, the daily usage record is calculated and stored in the storage unit 52 in association with the date. Further, the first temporary target boiling temperature calculation unit 51b calculates the necessary heat amount for the next day based on the average value of the usage results for a predetermined period (in the present embodiment, the past seven days) stored in the storage unit 52. At the same time, the first temporary target boiling temperature (first target boiling temperature) is calculated based on the calculated required heat quantity, and is output to the target boiling temperature determination unit 51d.

An example of a formula for calculating the daily usage results is shown below.
[Daily use result] = [The amount of remaining hot water in the tank the previous day (at the start of the day)] + [Total accumulated operation time of the heat pump unit 20 per day] × [Rated output of the heat pump unit 20] − [Same day (1 The amount of heat remaining in the tank at the end of the day]
[Amount of heat remaining in tank] = [Tank capacity] x [Average tank temperature] x [Specific heat of fluid (water) in tank]
Here, the rated output of the heat pump unit 20 is stored in the storage unit 52 in advance. The tank capacity is the capacity of the hot water storage tank 11 and is stored in the storage unit 52 in advance. The specific heat of the fluid (water) in the tank is also stored in the storage unit 52 in advance. The tank average temperature is calculated by performing a weighted average of the hot water temperature, which is a detection result of the temperature sensor 32, at a ratio of the corresponding tank capacity.

The necessary heat amount is the heat amount necessary for hot water supply from the current boiling to the next boiling, that is, the heat amount necessary for hot water supply on the next day, and an example of a calculation formula is shown below.
[Necessary heat amount] = [Average value of actual use over the past 7 days] + α
Here, α is a correction amount, and in the present embodiment, it is a standard deviation of the past use record for the past seven days.
Further, another example of the calculation formula for the required heat quantity is shown below.
[Necessary heat amount] = [Maximum use record for the past 7 days]

An example of the calculation formula for the first temporary target boiling temperature is shown below.
[First provisional target boiling temperature] = [Required heat amount] / ([Boiling capacity] × [Specific heat of fluid (water) in tank]) + [Water temperature detected by water temperature sensor 31]
The boiling capacity is a capacity that is heated by the heat pump unit 20 among the hot water stored in the hot water storage tank 11, and is equal to the tank capacity that is the capacity of the hot water storage tank 11 in the above-described calculation formula. Although set, the boiling capacity that is actually heated can be changed within a range not exceeding the tank capacity, as will be described later.

  The first temporary target boiling temperature calculation unit 51b corrects the first temporary target boiling temperature according to the operation mode of the water heater S, the previous (previous day) target boiling temperature, the amount of heating heat, and the like. It may be a configuration.

  The second temporary target boiling temperature calculation unit 51c reads the maximum value of the hot water supply temperature set value within a predetermined period stored in the storage unit 52, acquires the detection result (water temperature) of the water temperature sensor 31, and supplies the hot water supply temperature. Based on the maximum value of the set value and the water temperature, the second temporary target boiling temperature (second target boiling temperature) is calculated and output to the target boiling temperature determination unit 51d.

Here, the second temporary target boiling temperature is larger than the maximum value of the hot water supply temperature setting value and increases as the maximum value of the hot water supply temperature setting value is increased. An example of a calculation formula is shown below. .
[Second temporary target boiling temperature (° C.)] = [Maximum hot water supply temperature setting value (° C.)] + 22.5 − ([water temperature (° C.) detected by water temperature sensor 31] × 0.5)
For example, when the user supplies hot water at 45 ° C. on the current day, 48 ° C. on the previous day, and 45 ° C. on the previous day, the second temporary target boiling is performed based on 48 ° C., which is the maximum value of the hot water temperature setting value. The temperature is calculated.

  The target boiling temperature determining unit 51d acquires the first temporary target boiling temperature and the second temporary target boiling temperature, and the higher of the first temporary target boiling temperature and the second temporary target boiling temperature. Is determined as the target boiling temperature, and is output to the heat pump unit controller 51e.

  In addition, when the determined target boiling temperature exceeds the upper limit value, the target boiling temperature determination unit 51 sets the upper limit value (for example, 90 ° C.) as the target boiling temperature, and the determined target boiling temperature is When it is less than the lower limit value (for example, 65 ° C.), the lower limit value is set as the target boiling temperature.

  Here, the upper limit value is a value set from the viewpoint of protecting the hot water storage tank 11 and can be changed by the operation of the operation unit 42 of the operation terminal 40 by the user. Moreover, a lower limit is a value set from a viewpoint of ensuring the minimum calorie | heat amount, and the target boiling temperature determination part 51 determines automatically according to the operation mode of the water heater S. FIG.

The target boiling temperature determination unit 51d may change the actual boiling capacity based on the necessary heat amount and the determined target boiling temperature.
An example of the formula for calculating the boiling capacity after the change is shown below.
[Boiling capacity after change] = [Required heat amount] ÷ {([Target boiling temperature] − [Water temperature detected by water temperature sensor 31]) × [Specific heat of fluid (water) in tank]}

  The heat pump unit controller 51e acquires the target boiling temperature, and controls the heat pump unit 20 based on the target boiling temperature to heat the water in the hot water storage tank 11 to the target boiling temperature. Moreover, the heat pump unit control part 51e measures the accumulated operation time of the heat pump unit 20 for one day, and outputs it to the first temporary target boiling temperature calculation part 51b.

  The pump control unit 51f acquires the hot water supply temperature set value and the detection result (flow rate) of the hot water supply flow rate sensor 33, and controls the pump 12 based on the hot water supply temperature set value and the flow rate. Supply to the outside through the pipe 14h.

<Operation example>
Then, the operation example of target boiling temperature determination in the water heater S which concerns on embodiment of this invention is demonstrated with reference to FIG.

  This flow is started periodically, for example, at a predetermined time in the midnight time zone when the water heater S performs boiling in order to ensure the amount of heat necessary for hot water supply on the next day. First, when the first temporary target boiling temperature control unit 51a acquires various parameters, that is, the water temperature detected by the water temperature sensor 31 and the hot water temperature detected by the hot water temperature sensor 32 (Yes in step S1). The first temporary target boiling temperature calculation unit 51 b calculates the first temporary target boiling temperature based on various parameters, and the second temporary target boiling temperature calculation unit 51 c stores it in the storage unit 52. The second temporary target boiling temperature is calculated based on the maximum value of the hot water supply temperature set value within the predetermined period and the water temperature detected by the water temperature sensor 31 (the water temperature of the water supplied to the hot water storage tank 11) (step). S2).

  Subsequently, the target boiling temperature determination unit 51d sets the higher one of the first temporary target boiling temperature and the second temporary target boiling temperature as the target boiling temperature (step S3).

  When the set target boiling temperature is higher than the upper limit value (Yes in step S4), the target boiling temperature determination unit 51d resets the upper limit value to the target boiling temperature (step S5), and this flow Ends. On the other hand, when the set target boiling temperature is lower than the lower limit value (No in step S4 and Yes in step S6), the target boiling temperature determination unit 51d sets the lower limit value to the target boiling temperature. This is repeated (step S7), and this flow ends. When the set target boiling temperature is not less than the lower limit value and not more than the upper limit value (No in step S and No in step S6), the target boiling temperature determination unit 51d sets the set target boiling temperature. The raised temperature is used as it is, and this flow ends.

  The conventional water heater sets the target boiling temperature low by the learning function when the amount of hot water consumption is small. However, even if the latest hot water consumption is small, if the latest hot water supply temperature set value is high, a large amount of hot water may be consumed at a high hot water supply temperature set value. A tank set at a low temperature may not be able to cope with it.

  On the other hand, the water heater S according to the embodiment of the present invention includes a first temporary target boiling temperature that takes into account parameters such as a water temperature, a second temporary target boiling temperature that takes into account a hot water supply temperature setting value by a user, Since the higher one is used as the target boiling temperature, the target boiling temperature is increased when high-temperature hot water is supplied within a specified period while ensuring energy saving, which is inconvenient for the user. I do not feel.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably. For example, the hot water supply temperature set value stored in the storage unit 52 may be for one day or for one week. In the above embodiment, the hot water stored in the hot water storage tank 11 is used as a medium for heat exchange. However, the hot water stored in the hot water storage tank 11 may be mixed and supplied to the outside. Good. The liquid heating apparatus of the present invention is applicable to a liquid heating apparatus that heats and supplies a liquid, such as a hot water heater other than a hot water storage type hot water heater that stores hot water in the hot water storage tank 11.

11 Hot water storage tank (tank)
20 Heat pump unit (liquid heating part)
31 Water temperature sensor (sensors)
32 Hot water temperature sensor (sensors)
33 Hot water supply flow sensor 40 Operation terminal 50 Control device 51 Control unit 52 Storage unit S Water heater (liquid heating device)

Claims (3)

A liquid heating unit that heats the liquid, a tank that stores the heated liquid, a control device that controls the liquid heating unit, an operation terminal that is communicably connected to the control device, and the liquid heating A liquid heating device comprising sensors for detecting parameters for
The controller is
A storage unit that stores a liquid supply temperature setting value that is set within a predetermined period by the operation of the operation terminal and that supplies the liquid to the outside;
A first target boiling temperature is calculated based on the parameter, a second target boiling temperature is calculated based on the feed liquid temperature setting value within a predetermined period, and the first target boiling temperature and A control unit for controlling the liquid heating unit so as to heat the liquid using the higher one of the second target boiling temperatures as the target boiling temperature;
A liquid heating apparatus comprising: The controller is
When the target boiling temperature is higher than the upper limit value, the liquid heating unit is controlled using the upper limit value as the target boiling temperature,
2. The liquid heating apparatus according to claim 1, wherein when the target boiling temperature is lower than a lower limit value, the liquid heating unit is controlled using the lower limit value as a target boiling temperature. The control device calculates the first target boiling temperature based on the required heat amount, and changes the boiling capacity, which is the volume of the liquid to be heated, based on the target boiling temperature and the required heat amount. The liquid heating apparatus according to claim 1, wherein the liquid heating apparatus is provided.

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