JPH0154622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved configuration of a storage type heat pump water heater.

In order to improve the storage tank of a heat pump water heater to a simple and compact structure, we made the tank open to the atmosphere and provided a water supply passage that extends up and down inside the tank to improve the temperature of the hot water in the upper layer. The present applicant previously applied for a structure in which water is supplied to the bottom of the tank to prevent the water from decreasing.
This proposal was proposed in No. 66829 and Utility Model Application No. 57-200547, but this proposal has the following problems.

By the way, this problem mainly occurs when the outside air temperature is quite low and a considerable amount of stored hot water is used for bathing, and will be explained below with reference to FIG. 1.

Assuming that the hot water storage tank 1 is full of hot water, if a considerable amount of hot water is supplied to the bath, a low temperature (corresponding to the outside temperature) water corresponding to this amount of hot water will be sent to the inner bottom of the tank 1 via the boat tank 21 and the water supply passage 10. Water is supplied to position A.

During this water supply, the hot water in the upper part of the tank 1 is cooled by the low-temperature water passing through the water supply passage 10, but since the water and hot water are naturally flowing, the amount of heat exchange is small, so this does not pose much of a problem.

However, when hot water is used in small amounts at intervals during bathing, there is always low-temperature water in the water supply passage 10, and this water constantly cools the pooled hot water, so the temperature of the hot water will decrease. For example, even if the initial water temperature is 55℃, due to heat exchange,
Temperatures may drop below 45℃.

The problem was that hot water below 45°C was too low to be used as a ``pour bath'' into a bath, making it practically impossible and inconvenient.

When water is supplied to the inner bottom of the tank 1, the thermostat 20 for starting and stopping the compressor detects the low water temperature and starts heating operation, but in the case of a hot water storage method, the hot water is kept at a predetermined temperature and a predetermined amount over a long period of time. Since the heating capacity is not as large as that shown on the left, and the heating ability is poor, it is not possible to quickly heat the entire water temperature in tank 1 to the initially set temperature, for example, 55°C. is normal.

The present invention was made in order to solve the problems of the hot water storage type heat pump water heater as described above, and makes it possible to take out the last high temperature hot water even when a considerable amount of stored hot water is consumed at one time. The aim is to make the hot water storage tank more compact and more adaptable to demand, thereby promoting the spread of this type of water heater.

For this purpose, the first aspect of the present invention is to provide a heat source side unit having a compressor, a hot water storage tank, and a heating heat exchanger that is stored in the bottom of the hot water storage tank and heats the stored water using the heat acquired by the heat source side unit. a water supply passage that extends vertically within the hot water storage tank and supplies water to the bottom of the hot water storage tank; an electric heater for heating the stored water that is disposed at the top of the hot water storage tank;
a hot water take-out pipe 7 provided to be able to take out hot water in a layer above the electric heater 6 in the hot water storage tank 1;
a first water temperature detector that detects the water temperature at the bottom of the hot water storage tank; a first control circuit that drives the compressor when the water temperature is below a first set temperature; and a first control circuit that detects the water temperature near the electric heater. The hot water storage type heat pump water heater is equipped with a second control circuit that has a second water temperature detector and operates the electric heater when the water temperature is equal to or lower than a second set temperature that is lower than the first set temperature. When a large amount of stored hot water is temporarily consumed, the electric heater is activated to heat the hot water stored in the upper part of the hot water storage tank, thereby preventing a drop in temperature. Rapid heating can be achieved with a small volume, thus achieving the desired purpose.

Furthermore, a second invention of the present invention is provided with a selection means for maintaining at least one of the drive of the compressor and the operation of the electric heater in addition to the above-mentioned configuration, and the second invention is provided with a selection means for maintaining at least one of the drive of the compressor and the operation of the electric heater. When the temperature is extremely low, the heating heat exchanger and the electric heater are used for heating, when the temperature is normal, the heating heat exchanger is used for heating only, and when the heat source unit is inspected or a failure occurs, electricity is used. It is possible to use the selection means selectively, such as heating only with the heater,
It is designed to be more convenient in terms of usability.

Next, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a hot water storage tank, which includes a tank main body _1-1 with an open top and a lid _1-2 that covers this opening, and a slit around the lid _1-2 . The tank is formed into an open type tank that is open to the atmosphere through the tank, and the inner wall is surrounded by a heat insulating material to form a heat-retaining container.

At the inner bottom of the hot water storage tank 1, a heating heat exchanger 5 is disposed diagonally horizontally and connects to a heat source side unit 2, which will be described later, to heat the stored water using condensation heat. It has come to be heated using

Reference numeral 21 designates a water supply valve, such as an automatic water supply valve called a ball tap, provided on the upper side wall of the hot water storage tank 1, and has a water supply port at its tip opening downward at a position above a predetermined liquid level in the tank.

The hot water storage tank 1 has a hot water outlet pipe 7 pulled out from the side wall at a position slightly below the liquid level, an overflow pipe 8 pulled out from an appropriate location on the side wall, and a drain pipe 9 pulled out from the bottom wall. ing.

The hot water outlet pipe 7 hangs down inside the layer of heat insulating material, and then is drawn out of the tank from the lower part of the side wall via a pump 11, a check valve 12, and an accumulator 13 in series, and is connected to a hot water supply pipe 14.

Reference numeral 2 denotes a heat source side unit, which includes a compressor 15, an expansion valve 16, and a heat source side heat exchanger 17, and is connected to the heating heat exchanger (hereinafter referred to as a heating coil) 5 via two refrigerant pipes 18 and 19. A heat pump refrigeration cycle is formed in which the heating coil 5 acts as a condenser and the heat exchanger 17 acts as an evaporator.

Reference numeral 10 denotes a water supply passage, which is provided so as to guide makeup water released from the water supply valve 21 to the inner bottom of the tank.

This water supply passage 10 is formed as an independent passage extending vertically within the hot water storage tank 1, and can be easily constructed by providing a partition wall that extends vertically within the tank 1 and partitions it into two chambers. For example, a 100 mm diameter pipe made of heat-resistant polyethylene resin is vertically installed in the tank, and the upper end opening is located above the predetermined liquid level at a position where it can receive replenishment water discharged from the water supply valve 21. The lower end opening is provided facing the inner bottom.

Next, reference numeral 6 is an electric heater, for example, a sheathed heater is inserted liquid-tightly into the side wall of the tank and placed horizontally slightly below the predetermined liquid level in the upper part of the tank. It is designed to heat water.

20 is a first water temperature detector, for example a thermistor, attached to the lower part of the side wall of the tank in order to detect the water temperature at the inner bottom of the hot water storage tank 1; on the other hand, 22 is in order to detect the water temperature in the vicinity of the electric heater 6; A second water temperature sensor, such as a thermistor, is attached to the upper part of the side wall of the tank.

In the water heater having the above structure, an electric control circuit for heating the water in the hot water storage tank 1 to a predetermined temperature is shown in FIG. 2, and this control circuit uses the first thermistor 20 as an input signal element. a second control circuit 4 having the second thermistor 22 as an input element; and a selection means ₂ comprising a pair of selection switches _28-1 and 28-2 having an interlocking structure.
It has 3.

The first control circuit 3 and the second control circuit 4 share a series circuit of a temperature setting variable resistor VR and a resistor _R1 , and this intermediate potential VS is connected to an OP amplifier _24-1 ,
_24-2 and each input terminal.

The first control circuit 3 has at its output end a series circuit of a first relay _27-1 for driving the compressor 15 and an output transistor _26-1 , and connects the base of the output transistor _26-1 and the OP amplifier 24. _-1 output terminal is connected via NOT circuit _25-1 .

In the OP amplifier _24-1 , the intermediate potential _V1 of the series circuit of the first thermistor 20 and the resistor _R2 is applied to the input terminal, and the differential resistor R _D1 is connected between the input terminal and the output terminal. By setting resistors R ₁ , R ₂ , and R _D1 to appropriate values and operating the variable resistor VR, for example, when the water temperature at the bottom of the hot water storage tank 1 drops below 50°C, V Since _s > V ₁ , the OP amplifier _24-1 becomes “L”
An output is generated and converted to "H" by the NOT circuit _25-1 , and as a result, the transistor _26-1 becomes conductive, energizing the first relay _27-1 , and driving the compressor 15.

This state in which the OP amplifier _24-1 outputs "L" is maintained until the water temperature rises to 53°C and V _s < V ₁ , at which point the OP amplifier _24-1 outputs "H". The first relay 27-
₁ is deenergized and the compressor 15 is stopped.

In this way, the first control circuit 3 is structured to have a differential of 3°C between the operating point at which it changes from on to off (53°C) and the operating point at which it changes from off to on (50°C). .

On the other hand, the second control circuit 4 controls the second thermistor 2
2. Resistor R ₃ , OP amplifier 24- ₂ , Resistor R _D2 , NOT
The circuit _25-2 , the output transistor _26-2 , and the second relay _27-2 are the first thermistor 20, the resistor _R2 , the OP amplifier _24-1 ,
They correspond to the resistor R _D1 , the NOT circuit _25-1 , the output transistor _26-1 , and the first relay _27-1 , respectively, and the basic circuit configuration is the same, so the explanation will be omitted, but the resistors _R2 and R _D2 The difference is that the value of is selected so that the differential is 8° C., which is larger than the differential of the first control circuit 3.

In this example, the operating point (53°C) at which the ON to OFF transition is the same as that of the first control circuit 3, but the operating point at which the OFF to ON transition occurs is lower than that of the first control circuit 3. The temperature is set at 45℃.

In addition, since the variable resistor VR and the resistor _R1 are shared by both circuits 3 and 4, it is possible to change the operating point from ON to OFF at the same value and change the height. The differential is set at 3°C and 8°C, but in addition to this example, as shown by the broken line frame,
A fixed type series circuit consisting of R ₃ and R ₄ is provided exclusively for the OP amplifier _24-2 to separate the second control circuit 4 and the first control circuit 3. ), it is of course possible to use a fixed type with the off-operating point (53°C).

Next, the selection means 23 will be explained.The selection switch _28-1 is interposed in the middle of the wiring connecting the coil of the first relay _27-1 and the power supply, and the selection switch _28-2 is connected to the coil of the second relay _27-2 . It is interposed in the middle of the wiring that connects the coil and the power source.

When both selection switches _28-1 and _28-2 are set to ON, only the coil of the second relay _27-2 is connected to the power supply, and when set to NO, only the coil of the first relay _27-1 is connected to the power supply. and if it is connected to Notsuchiha, both relays 27
Both coils ₁ and _27-2 are connected to the power supply.

In the water heater having the configuration described above, when the selection means 23 is set to NO and the power switch (not shown) is turned on, the first control circuit 3 is switched on while the water temperature in the hot water storage tank 1 is lower than 45°C. and second control circuit 4
As a result, the water temperature in the tank 1 gradually rises as a result of the compressor 15 being driven and the electric heater 6 being heated.

In this case, the water temperature in the upper layer reaches 55
℃, the second control circuit 4 becomes inactive,
The electric heater 6 becomes inoperative first.

Thereafter, when the temperature of the water layer at the inner bottom reaches 55°C, the first control circuit 4 becomes inactive, and the compressor 1
5 stops and the heating operation ends.

Thus, the entire hot water stored in the hot water storage tank 1 has reached a high temperature of 55°C.

After that, when hot water is needed for a bath, kitchen, etc., and hot water is supplied from the hot water storage tank 1, make-up water corresponding to the amount of hot water supplied is supplied to the inner bottom of the tank 1 through the water supply passage 10, and as a result, the first control circuit 3 is activated. The compressor 15 is driven, and the heating coil 5 performs heating operation, while the electric heater 6 is inactive while the water temperature in the upper layer is high.

When a large amount of hot water is temporarily consumed, such as when taking a bath, the temperature of the water in the upper layer of the tank 1 naturally decreases, so the second control circuit 4 is activated. As a result of the additional heating operation by the electric heater 6, the hot water in the tank 1 can be rapidly raised to a predetermined temperature, and high-temperature hot water suitable for "hot water" can be continuously supplied.

In this way, the electric heater 6 heats only the hot water in the upper layer that is immediately necessary for hot water supply.

It should be noted that the electric heater 6 is often not needed when the outside temperature is average, except when the outside temperature is extremely low. It is possible to force it to be inactive.

According to the present invention having the configuration and operation described above, in a hot water storage type heat pump water heater, when a large amount of hot water is temporarily supplied, hot water in the upper part of the tank that is immediately used for hot water supply is transferred to the electric heater 6. By heating the water further, the hot water in the upper layer can be maintained at a high temperature within a short period of time, making it possible to constantly supply hot water. This has the effect of ensuring stable supply.

In addition, the electric heater 6 is configured such that the hot water in the upper layer, which is heated by the heating heat exchanger 5 and is supposed to reach the first set temperature T ₁ first by convection, is set at a second set temperature lower than the set temperature T ₁ . Since heating is performed only when the temperature is T ₂ , it is effective for heating during the transition period between reheating in the hot water storage tank 1 and auxiliary heating within a short time at the start of operation. It can be handled with a relatively small capacity device.

Furthermore, the electric heater 6 only heats the hot water in the upper layer in a complementary manner, and the heating heat exchanger 5 is mainly used for heating, so it is possible to perform a heating operation with a high EER.

Furthermore, the second invention adds a selection means 23, so that the combination operation of the electric heater 6 and the forced stop at times when the electric heater 6 is hardly needed can be selectively used with a single switch operation, further improving the operating economy. Adds potential benefits.

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram according to an embodiment of the present invention;
FIG. 2 is an electrical control circuit for the water heater shown in FIG. 1...Hot water storage tank, 2...Heat source side unit, 3
...First control circuit, 4...Second control circuit, 5...
Heating heat exchanger, 6... Electric heater, 7... Hot water outlet pipe, 10... Water supply passage, 15... Compressor,
20...first water temperature detector, 22...second water temperature detector, 23...selection means.

Claims (1)

[Scope of Claims] 1. A heat source side unit 2 having a compressor 15, a hot water storage tank 1, and a heating heat source stored in the inner bottom of the hot water storage tank 1 for heating stored water using the heat acquired by the heat source side unit 2. An exchanger 5, a water supply passage 10 that extends vertically within the hot water storage tank 1 and supplies water to the bottom of the hot water storage tank 1, an electric heater 6 for heating the stored water disposed at the top of the hot water storage tank 1, and the hot water storage tank 1. A hot water take-out pipe 7 is provided to allow hot water to be taken out from a portion above the electric heater 6 in the tank, and a first water temperature detector 20 detects the water temperature at the bottom of the hot water storage tank 1, and the water temperature is set to a first set temperature. A first control circuit 3 that drives the compressor 15 when T ₁ or less, and a second water temperature detector 22 that detects the water temperature near the electric heater 6.
and a second control circuit 4 that operates _the electric heater 6 when the water temperature is lower than a second set temperature _T2 which is lower than the first set temperature T1. Heat pump water heater. 2. A heat source side unit 2 having a compressor 15, a hot water storage tank 1, a heating heat exchanger 5 that is stored in the inner bottom of the hot water storage tank 1 and heats the stored water using the heat acquired by the heat source side unit 2, and a hot water storage tank 1. A water supply passage 10 that extends vertically within the tank 1 and supplies water to the bottom of the hot water storage tank 1 , an electric heater 6 for heating the stored water disposed at the top of the hot water storage tank 1 , and an electric heater 6 inside the hot water storage tank 1 . It also has a hot water take-out pipe 7 provided to be able to take out hot water from the upper layer, and a first water temperature detector 20 that detects the water temperature at the bottom of the hot water storage tank 1, when the water temperature is below a first set temperature _T1 . A first control circuit 3 that drives the compressor 15 and a second water temperature detector 22 that detects the water temperature near the electric heater 6.
a second control circuit 4 that operates the electric heater 6 when the water temperature is lower than a second set temperature T ₂ that is lower than the first set temperature T ₁ ; A hot water storage type heat pump water heater characterized by comprising a selection means 23 for maintaining at least one of the operation of the hot water storage type heat pump water heater.