JP2007057168A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type water heater capable of accurately detecting degradation of heating capacity of a heat pump in association with a secular change or the like. <P>SOLUTION: The hot water storage type water heater including a heat pump of a power operation type in a heat pump unit 2 which heats water flowing in a circulation circuit 20 for delivering water on a lower part in the hot water storage tank 1 to an upper part in the hot water storage tank 1 to make high temperature hot water, is provided with a calculation means for calculating an effective output heat quantity of the heat pump which is a sum of an increased heat quantity which increases after a boiling instruction is made to the heat pump and a reduced heat quantity which is reduced by discharge of hot water during boiling arranged in a control device 3. When the heat pump effective output heat quantity calculated by the calculation means, does not reach a predetermined heat quantity within a predetermined period after the boiling instruction is made to the heat pump, it is determined that heating capacity of the heat pump is degraded, and a target boiling temperature when the boiling instruction is made to the heat pump is corrected to be high. Furthermore, when a difference between the heat pump effective output heat quantity and the predetermined heat quantity exceeds a predetermined threshold, that is notified to a user through display means 53, 55. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water storage hot water supply apparatus that operates a heat pump with electric power and heats the water supply until it reaches a target heat storage amount commanded by the control device and stores it in a hot water storage tank, and in particular, accurately reduces the heating capacity of the heat pump. The present invention relates to a hot water storage type hot water supply apparatus that can detect well and notify a user.

  2. Description of the Related Art Conventionally, there is a hot water storage type hot water supply device that stores high temperature hot water heated by an electric power operated heat pump in a hot water storage tank. In particular, as this type of hot water supply device, the bottom water in the hot water storage tank is heated by a heat pump and sent as hot water to the top of the hot water storage tank, making use of the difference in specific gravity of water at different temperatures. It is known that hot water is stored on the upper side of the inside so as not to mix with the water on the lower side in the hot water storage tank. When the hot water in the hot water storage tank is output (for example, the tap is opened and the hot water is consumed outside the hot water storage tank), hot water is supplied from the hot water outlet pipe connected to the uppermost part of the hot water storage tank. Water is supplied into the hot water storage tank from the connected water supply pipe. Recently, it is also common to have a function as a heating heat source. In addition, hot water can be poured into the bathtub, and hot water poured at the set temperature of the user's preference has cooled in the bathtub. Sometimes, the hot water in the bathtub is circulated through a heat exchanger for reheating that is thermally coupled to the hot water in the hot water storage tank, and reheating is also possible.

However, one of the important factors in such a hot water storage type hot water supply apparatus is the heating capacity monitoring of the heat pump. If the capacity is reduced with time, it is necessary to determine the heating capacity in order to notify the user of a maintenance request so as not to cause unnecessary power consumption. Therefore, in the past, from the above viewpoint, as recognized in the following Patent Document 1, even if the apparatus is operated with the maximum control ability after starting the apparatus, the heat pump reaches the temperature at the top of the hot water storage tank until a predetermined time elapses Some have determined that the heat pump system has failed when the discharge temperature does not reach the predetermined temperature.
JP 2002-213816

  However, this method has a drawback that accuracy is not so good because the determination is simply based on the temperature rise, and correct determination cannot be made in the first place when tapping hot water during boiling.

  In view of this point, the present invention is intended to provide a hot water storage type hot water supply apparatus that can accurately detect a reduction in heating capacity of a heat pump. If accurate detection is possible, for example, control that keeps using the heat pump as much as possible while avoiding user discomfort due to insufficient hot water storage, etc. until the life of the heat pump is completed. Do not inadvertently cause malfunctions or judgments when notifying the user of a situation where it is necessary to judge that the power loss will be unacceptable if the user continues to use the product or the comfort cannot be maintained. That's it.

In order to achieve the above object, the present invention
A calculating means for calculating an effective output heat amount of the heat pump as a sum of an increased heat amount that is increased by boiling after giving a boiling instruction to the heat pump and a reduced heat amount that is decreased by tapping during boiling;
Determining means for determining that the heat pump effective output heat quantity calculated by the calculating means does not reach a predetermined heat quantity within a predetermined period after the heating pump is instructed to be heated;
The hot water storage type hot water supply apparatus characterized by having is proposed.

  The present invention further provides a specific mode after satisfying the above-described structural requirements, and after the determination means determines that the heat capacity of the heat pump has been reduced, the target boiling temperature at the time of instructing the heating to the heat pump is increased. A hot water storage type hot water supply device characterized by correction is also proposed.

  Furthermore, in another aspect of the present invention, when the difference between the heat pump effective output heat amount calculated by the calculation means and the predetermined heat amount exceeds a predetermined threshold value, the determination means has a remarkable heating capability. A hot water storage type hot water supply apparatus is also proposed in which the notification means is activated based on the determination that the battery has fallen, and the user is mainly notified for a maintenance request.

  According to the present invention, since the heating capacity is determined based on the effective increased heat amount including the amount of heat consumed by the tapping water, the heating capacity of the heat pump is reduced without being affected by the usage status of the tapping volume. Can be detected accurately. As a result, it is possible to control the heat pump without causing any discomfort to the user, and there is no doubt that it will be possible to control the accuracy of the heat pump. Can be expected. Note that the notification means used at this time may be visible, audible, or both, and may be placed on an operation panel or the like of the device.

  FIG. 1 shows a configuration example of a hot water storage type hot water supply apparatus to which the present invention can be applied. The hot water storage tank 1 is usually made of metal having excellent corrosion resistance (for example, made of stainless steel), and a heat insulating material (not shown) is arranged on the outer peripheral portion, so that hot water for hot water supply can be kept warm for a long time. The shape is generally vertically long, and an inlet 11 is provided on the bottom surface. A water supply pipe 12 for introducing water supply (generally tap water) Wf is connected to the inlet 11 at the bottom of the hot water storage tank 1. Has been.

  The water supply pipe 12 is provided with a water supply thermistor 21 which is a water supply temperature detection means, and outputs temperature information in the water supply pipe 12 to the control device 3. A bypass pipe 15 that branches from the position where the water supply thermistor 21 is provided in the middle of the water supply pipe 12 and connects to the mixing valve 16 described later is connected to the downstream side.

  A lead-out port 13 is provided at the uppermost part of the hot water storage tank 1, and a lead-out pipe 14, which is a hot water supply path for leading the hot water in the hot water storage tank 1, is connected to the lead-out port 13. The mixing valve 16 provided in the middle of the path can adjust the mixing ratio between the hot water from the outlet pipe 14 and the tap water Wf supplied from the bypass pipe 15 by adjusting the opening area ratio. It has become. In general, the mixing valve 16 is an electric valve that adjusts the opening degree of each path by driving a valve body by a drive source (not shown) such as a servomotor, and is operated by a control signal from the control device 3. The state is also returned to the control device 3.

  The outlet side of the mixing valve 16 is connected to a tap hot water pipe 17 which is a mixed hot water path to the hot water outlet 43 of a faucet, a shower, a bath, etc., and the hot water thermistor 41 which is a hot water temperature detecting means and the amount of hot water detected are connected to this pipe 17. A flow rate counter 42 as means is provided, and the hot water thermistor 41 outputs temperature information in the pipe 17, and the flow rate counter 42 outputs information on the flow rate in the pipe 17 to the control device 3.

  The lower part of the hot water storage tank 1 is provided with a suction port 18 for sucking the lowermost water in the hot water storage tank 1, and the hot water is discharged toward the uppermost part of the hot water storage tank 1 toward the uppermost part of the hot water storage tank 1. A discharge port 19 is provided for this purpose. The suction port 18 and the discharge port 19 are connected by a circulation circuit 20, and a part of the circulation circuit 20 is disposed in the heat pump unit 2 controlled by the control device 3.

  A substantial heat pump portion disposed in the heat pump unit 2 of the circulation circuit 20 is provided with a heat exchanger (not shown), and the water in the hot water storage tank 1 sucked from the suction port 18 is desirably high-temperature carbon dioxide refrigerant. The water in the hot water storage tank 1 is boiled by being heated by heat exchange with the water and returning to the hot water storage tank 1 from the discharge port 19. When carbon dioxide is used as the refrigerant for the heat pump, it is possible to increase the refrigerant discharge temperature from a power-operated compressor (not shown) by using the supercritical region. Boil up efficiently. The hot water heated by the heat pump can be returned to the suction port 18 side as needed via the bypass three-way valve 23.

  A plurality of (six in this embodiment) water level thermistors 31 to 36 are arranged on the outer wall surface of the hot water storage tank 1 at substantially equal intervals in the vertical direction (the height direction of the hot water storage tank 1), and are filled in the hot water storage tank 1. The temperature information at each water level is output to the control device 3. Therefore, the control device 3 can also detect the boundary position between the hot water heated in the upper part of the hot water tank 1 and the water before being heated in the lower part of the hot water tank 1 based on the temperature information from each water level thermistor.

  Of course, the water level thermistor 31 provided on the uppermost outer wall surface of the hot water storage tank 1 is a tank output hot water that detects the uppermost water temperature in the hot water storage tank 1 that is the temperature of the hot water drawn from the outlet 13 to the outside. It also has the function of a warm thermistor.

  Generally, in addition to this, a piping system for heating and the like is also connected, but these are omitted because they are not directly related to the present invention.

  The control device 3 receives information from the outside air temperature thermistor 22 which is an outside air temperature detecting means provided in the heat pump unit 2 and the like in addition to the hot water flow rate information from each thermistor and the flow rate counter 42 described so far. The heat pump unit 2 and the mixing valve are based on signals from operation switches provided on the operation panel of a remote controller unit (shown as kitchen remote control 52 and bath remote control 54 in the figure) provided in the kitchen or bathroom. 16 is configured to control.

  When the power switch (not shown) of the hot water supply device is turned on, the control device 3 detects temperature information from each thermistor provided in the hot water storage tank 1, time information set by an operation panel (not shown), etc. Based on the above, the heat pump unit 2 is appropriately operated to heat the water in the hot water storage tank 1 and boil it up to high temperature hot water (for example, 90 ° C. hot water). As described above, the outside temperature thermistor 22 for detecting the temperature of the outside air is also provided at an appropriate location such as the heat pump unit 2, and the above bypass is used to prevent the circulation circuit 20 from freezing due to a temperature drop depending on the season. By switching the three-way valve 23 to the suction port 18 side, the heat pump can be driven to perform the freeze prevention operation.

  Further, when the flow rate counter 42 detects the flow of water (hot water) in the hot water supply pipe 17, it means that the user has used hot water through the hot water outlet 43. Therefore, at this time, the control device 3 controls the opening area ratio of the mixing valve 16 based on the temperature information from the water supply thermistor 21, the water level thermistor 31, and the hot water thermistor 41 according to the set temperature at that time, so that the set temperature is reached. Try to get hot water at a near temperature. That is, when the set temperature is equal to or lower than the detected temperature of the water level thermistor 31, the control device 3 first sets the mixing valve 16 in the communication state between the bypass pipe 15 and the pipe 17 and shuts off the direction of the pipe 14 and then The ratio of the opening area of the mixing valve 16 is roughly adjusted from the detected temperature of the water supply thermistor 21 and the detected temperature of the water level thermistor 31, and then the mixing valve is set so that the hot water supply temperature becomes the set temperature based on the temperature information from the hot water thermistor 41. The aperture area ratio of 16 is finely controlled.

  The above-described heating instruction to the heat pump is, as a general rule, given at a predetermined time in the midnight time zone when the power rate setting is low. However, of course, a minimum hot water storage amount is generally set in order to prevent running out of hot water, and boiling is started when the hot water amount is insufficient even in a time zone other than the midnight time zone.

However, in the hot water storage type hot water supply apparatus of the present invention, when a heating instruction is given to the heat pump and control is started, a calculation means (not shown) provided in the control device 3 increases the amount of heat increased by boiling. Calculate from time to time. For the calculation of this increased heat amount, the current effective hot water storage amount obtained from the temperature information from the thermistors 31 to 36, the average temperature in the tank,
Quantity of heat Q = Effective amount of stored hot water x Specific gravity x (Average tank temperature-Feed water temperature)
The following formula is used. In this embodiment, the water supply temperature is the temperature of water detected by the water supply thermistor 21. Therefore, the increased amount of heat Qi increased by boiling over time is obtained by subtracting the amount of heat Qs at the start of boiling from the current amount of heat Qe. The calculation means can be substantially constituted by a microcomputer incorporated in the control device 3 in recent years.

On the other hand, when the hot water is discharged during the boiling operation and the amount of hot water is reduced, the calculation means in the control device 3 also calculates this reduced heat amount as needed. To calculate this reduced heat quantity Qd,
Quantity of heat Qd = Hot water used x Specific gravity x (Tempered water temperature-Feed water temperature)
The following formula is used.

  From this, the effective output heat quantity Qa, which is obtained by the calculation means and is actually heated by the heat pump, is Qi + Qd, which is the sum of both the increment and decrement, and boiling by the heat pump is over a predetermined time. When continuously executed, a judgment means (not shown) provided in the control device 3 is used when the effective output heat quantity Qa increased after a predetermined time from the start of boiling does not reach a predetermined predetermined heat quantity Qt. It is determined that the heating capacity of the heat pump is reduced.

  The determination means can also be constituted by a microcomputer incorporated in the control device 3 recently. However, after the determination means determines that the heating capacity of the heat pump is reduced, for example, the control device 3 instructs the heat pump to boil up. In this case, the target boiling temperature can be corrected to be higher. In this way, the heat pump can be used as it is during the life of the heat pump without causing the user to feel uncomfortable due to insufficient hot water storage.

  More preferably, if the difference Qt-Qa between the heat pump effective output calorie calculated by the calculating means and the predetermined heat quantity exceeds a predetermined threshold Δd, the judging means judges that the heating capacity is significantly reduced. It can be configured to notify the user mainly for a maintenance request.

  As a notification means for this purpose, a display device attached to an operation panel or the like provided at an appropriate place, for example, the display device 53 attached to the kitchen remote control 52 or the display device 55 attached to the bath remote control 54 is used. It can be configured so that a notification to that effect is made here. The display device may be a visual display device, an audible display device, or both.

  As described above, according to the present invention, when there is a heat quantity Qd consumed during boiling, the effective output heat quantity Qa of the heat pump is obtained by adding to the current heat quantity Qe, and reaches the predetermined heat quantity Qt. Since the determination of the heat pump capacity is performed based on whether or not it is performed, the temperature correction control is not based on an erroneous determination that is influenced by the use amount of the hot water. Further, even when the notification means is finally operated, there is no mistake in the criteria for determining whether or not to notify.

  In the above-described embodiment, for the sake of simplicity, the use of hot water is summarized only for the hot water from the hot water outlet 43, but the calorific value may be calculated separately for hot water supply in the kitchen and hot water filling in the bath. In addition, not only when the heat pump is finally determined to be unusable, but also when the target boiling temperature is corrected to a higher level, in a sense during normal operation, the user is notified accordingly. You may make it do.

It is a schematic block diagram of one Embodiment of the hot water storage type hot water supply apparatus which concerns on this invention.

Explanation of symbols

1 Hot water storage tank 2 Heat pump unit 3 Control device
11 Introduction
12 Water supply piping
13 Outlet
14 Outlet tube
15 Bypass piping
16 Mixing valve
17 Pouring pipe
18 Suction port
19 Discharge port
20 Circulation circuit
21 Water supply thermistor
22 outside temperature thermistor
23 Bypass 3-way valve
31-36 Water level thermistor
41 Hot spring thermistor
42 Flow counter
43 Hot Spring

Claims (3)

In a hot water storage type hot water supply apparatus having an electric power operation type heat pump that heats water flowing in a circulation circuit that sends water in the lower part of the hot water storage tank to the upper part of the hot water storage tank to produce hot water;
Calculating means for calculating an effective output heat amount of the heat pump as a sum of an increased heat amount that increases after the boiling instruction to the heat pump and a reduced heat amount that decreases due to the tapping hot water;
Determining means for determining that the heat pump effective output heat amount calculated by the calculating means does not reach a predetermined heat amount within a predetermined period after the heating pump is instructed to be heated;
A hot water storage type hot water supply apparatus characterized by comprising: The hot water storage type hot water supply device according to claim 1,
After the determination means determines that the heating capacity of the heat pump is reduced, the target boiling temperature at the time of the heating instruction to the heat pump is corrected to be higher;
Hot water storage type hot water supply device characterized by The hot water storage type hot water supply device according to claim 1,
When the difference between the heat pump effective output heat calculated by the calculation means and the predetermined heat quantity exceeds a predetermined threshold value, the determination means determines that the heating capacity is significantly reduced, and accordingly That the notification means for notifying is activated;
Hot water storage type hot water supply device characterized by

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