JPH0718938Y2 - air conditioner - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention relates to an air conditioner in which a heat storage tank is incorporated in a refrigeration cycle, and particularly when storing heat in the heat storage tank, an air conditioner capable of optimal heat storage. It is about.

(Prior Art) A heat storage type air conditioner is connected to a heat storage tank in which a heat storage material that exchanges heat with the discharged refrigerant is enclosed on the discharge side of a variable capacity compressor driven by an inverter device. An indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger are connected in this order to form a refrigeration cycle.

In this heat storage type air conditioner, when the air conditioning operation is not performed, the heat storage material in the heat storage tank is heated by the refrigerant discharged from the compressor to store heat.

That is, the indoor fan of the indoor heat exchanger is stopped, the outdoor fan of the outdoor heat exchanger is driven, and the high temperature and high pressure refrigerant of the compressor is condensed in the heat storage tank to store heat.

During the heat storage dedicated operation, the temperature in the heat storage layer is detected, and the compressor is stopped when the heat storage temperature reaches a predetermined temperature.

After the heat is stored in the heat storage tank in this way, the heat storage is used as a heat source when the heating is started or used as a heat source during the defrosting operation.

(Problems to be solved by the invention) However, since a heat storage material that uses latent heat such as paraffin is used as the heat storage material in the heat storage tank, the heat storage material is in a solid state at the start of the heat storage operation, and the heat conduction The rate is low, the temperature gradient in the heat storage layer is large, and even if the temperature is detected, the detected temperature varies depending on the position of the sensor, and it cannot be said that the detected temperature necessarily detects an appropriate heat storage temperature.

Therefore, even though the actual temperature of the heat storage layer has risen to some extent, the detected temperature is low.Therefore, if the compressor is kept operating at a high capacity, its condensing pressure rises abnormally and the compressor There is a problem of breaking down and stopping.

In order to protect the compressor, it usually takes a few minutes for the compressor to restart, so there is a problem that the compressor does not operate as expected during heat storage dedicated operation and is extremely inefficient.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an air conditioner capable of storing heat according to the amount of heat that is actually stored in the heat storage tank.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention sequentially connects a variable capacity compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger. To form a refrigeration cycle, and between the compressor and the four-way valve of the refrigeration cycle, a heating heat exchanger through which refrigerant discharged from the compressor passes is connected and the heating heat exchanger is placed in a heat storage tank. In the air conditioner housed in the above, in the heating heat exchanger and the indoor heat exchanger, which serve as a condenser during the heat storage dedicated operation, a refrigerant temperature sensor is provided on the refrigerant outlet side of the heating heat exchanger, and the compressor is operated during the heat storage dedicated operation. When the maximum operating frequency of is set lower than the maximum operating frequency during normal heating, the compressor is operated, the indoor fan is stopped, and the temperature detected by the refrigerant temperature sensor reaches a certain value. The discharged refrigerant of the After condensed flows in, the condensate to flow directly to the indoor heat exchanger, in which so as to reduce the ability of the variable capacity compressor.

(Operation) According to the above configuration, at the time of exclusive heat storage operation, the heat exchangers that can be the condenser are the heat exchanger and the indoor heat exchanger, so that condensation does not occur in the indoor heat exchanger, that is, The maximum operating frequency of the compressor is set lower than the maximum operating frequency during normal heating so that the refrigerant leaving the heating heat exchanger flows into the indoor heat exchanger as it is, and the temperature inside the heat storage tank rises, When the temperature detected by the temperature sensor reaches a certain value, the capacity of the compressor is controlled so that the refrigerant leaving the heating heat exchanger flows into the indoor heat exchanger as it is, that is, the heating heat exchanger. By controlling so that the condensation is completed with, the heat exchange in the indoor heat exchanger does not occur during the dedicated heat storage operation (without affecting the indoor temperature), and there is no stop due to the breakdown of the compressor. Optimal heat storage dedicated operation You can do it.

(Embodiment) A preferred embodiment of the air conditioner of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a refrigerating cycle of an air conditioner of the present invention. In the figure, 1 is a variable capacity compressor driven by an inverter device 2 or the like, and a heat storage tank 3 is connected to its discharge side.

From this heat storage tank 3 through one port of the four-way valve 4, the indoor heat exchanger 5, the first two-way valve 6, the decompression device 7 such as an expansion valve, the outdoor heat exchanger 8, the other port of the four-way valve 4 Through the check valve 9 and the suction side of the compressor 1 to form a refrigeration cycle.

The heat storage tank 3 has a heating heat exchanger 10 through which the high-temperature high-pressure refrigerant from the compressor 1 flows, and an endothermic heat exchanger 11 through which the refrigerant condensed through the indoor heat exchanger 5 passes, and paraffin is stored in the tank 3. The heat storage material 12 having a melting point of about 40 to 50 ° C. is enclosed and formed.

In the heat storage tank 3, a heat storage temperature sensor 21 that detects the temperature of the heat storage material 12 is provided. A refrigerant temperature sensor 22 is provided on the refrigerant outlet side of the heat storage tank 3, that is, on the outlet side of the heating heat exchanger 10.

The indoor heat exchanger 5 is provided with an indoor fan 13 such as a cross flow fan, and the outdoor heat exchanger 8 is provided with an outdoor fan 14 such as a propeller fan. Further, the indoor heat exchanger 5 is provided with an indoor heat exchange temperature (condensation temperature) sensor 23.

Between the indoor heat exchanger 5 and the first two-way valve 6, a heat storage utilization line 15 for connecting the condensed refrigerant from the indoor heat exchanger 5 to the heat absorption heat exchanger 11 of the heat storage tank 3 is connected, and the line 15 is connected to the second A two-way valve 16 is connected. The heat absorption heat exchanger 11 has a heat storage utilization line 15
A return line 17 for returning the refrigerant from the above to the suction side of the compressor 1 is connected, and a third two-way valve 18 is connected.

The defrosting line 19 for flowing the refrigerant flowing through the line 17 to the outdoor heat exchanger 8 is connected to the return line 17, and the fourth two-way valve 20 is connected to the line 19.

The inverter device 2 outputs a three-phase alternating current having an output frequency of, for example, 30 to 120 Hz to the compressor 1 according to the air conditioning load, and controls the compressor 1 to have a compression capacity according to the air conditioning load. Alternatively, during the heating heat storage operation described later, the frequency operation range is set to 30 to 120 Hz according to the difference between the set temperature and the room temperature, and during the heat storage dedicated operation, the heat storage temperature detected by the heat storage temperature sensor 21 corresponds to the heat storage temperature. The compressor 1 is driven so that the frequency becomes 30 to 90 Hz.

Further, in the present embodiment, the example in which the compressor 1 is controlled to be variable in capacity by the inverter device 2 has been described, but the compressor 1 may be directly driven by a commercial power source to start / stop it.

The detection output of the refrigerant temperature sensor 22 (or the indoor heat exchange temperature sensor 23) is input to a control device (not shown), and during the heat storage dedicated operation, as shown in FIG. When the temperature reaches a temperature lower than a certain value (for example, 50 ° C.), the inverter device 2 is controlled to increase the output frequency value. Further, when the compressor 1 is driven by the commercial power source, the control device controls so that the compressor 1 is stopped when it reaches a certain value, and is started when the temperature drops to a certain temperature.

Next, the operation of this embodiment will be described.

First, during normal heating, during heat storage heating and during heat storage dedicated operation,
Of the first to fourth two-way valves 6,16,18,20, the second to fourth two-way valves 16,18,20 are closed except that the first two-way valve 6 is opened.

During normal heating, the high-temperature high-pressure refrigerant from the compressor 1 is stored in the heat storage tank 3
Of the four-way valve 4 to the indoor heat exchanger 5 through the heating heat exchanger 10 as it is, where it is condensed by heat exchange with the indoor air sucked and blown by the indoor fan 13, After the pressure is reduced by the pressure reducing device 7 via the two-way valve 6,
It flows to the outdoor heat exchanger 8, where it exchanges heat with the outside air blown by the outdoor fan 14 to be evaporated and returns to the compressor 1 via the other port of the four-way valve 4 and the check valve 9.

During this heating, the heat storage material in the heat storage tank 3 is in a state where heat is stored therein, and the high-temperature high-pressure refrigerant discharged from the compressor 1 flows to the indoor heat exchanger 5 side without being condensed.

Further, in the heating and heat storage operation, the flow of the refrigerant is the same as that in the normal heating, but the heat storage material 12 in the heat storage tank 3 is in a state where the heat is not yet sufficiently stored, and the high temperature and high pressure refrigerant from the compressor 1 is discharged. The heat storage material 12 is heated by a part of the heat and then flows into the indoor heat exchanger 5.

The output frequency range of the inverter device 2 during the normal heating and heating heat storage operation is operated in the range of 30 to 120 Hz according to the difference between the set temperature set by the user and the detected room temperature. That is, when the air conditioning load is large (when the room temperature is lower than the set temperature), it is operated at the maximum frequency value of 120 Hz, and if the air conditioning load decreases thereafter, it is gradually decreased to 30 Hz and operated. .

Next, the case of the heat storage dedicated operation will be described.

First, when the heat storage temperature sensor 21 measures the temperature of the heat storage material 12 at a predetermined temperature or less during the heat storage dedicated operation, the compressor 1 has a predetermined capacity (for example, a maximum operating frequency of 120 Hz during normal heating operation).
The maximum output frequency during heat storage dedicated operation is set to 90 Hz, which is lower than 120 Hz), the indoor fan 13 is stopped, and the outdoor fan 14 is driven.
The two-way valves 6, 16, 18, 20 are opened and closed in the same manner as in normal heating and heating heat storage operation.

In this state, the high-temperature high-pressure refrigerant from the compressor 1 flows through the heating heat exchanger 10 of the heat storage tank 3, where it is condensed by heat exchange with the heat storage material 12, and the condensate flows through the indoor heat exchanger 5 as it is.
The pressure is reduced by the pressure reducing device 7 through the first two-way valve 6, evaporated by the outdoor heat exchanger 8, and returned to the compressor 1 through the four-way valve 4 and the check valve 9. In this way, the high-temperature high-pressure refrigerant from the compressor 1 exchanges heat with the heat storage material 12 in the heat storage tank 3, whereby the heat storage material 12 is heated and the heat is stored.

At the start of the heat storage dedicated operation, the heat storage material 12 is in a solid state, its thermal conductivity is low, and the temperature difference between the temperature at the start of heat storage and the temperature of the heating heat exchanger 10 is large, so the heat storage temperature sensor 21 However, it is difficult to detect the actually stored temperature. Therefore, the condensation temperature is detected by the temperature detected by the refrigerant temperature sensor 22 (or the indoor heat exchange temperature sensor 23), and the compressor 1 is controlled by the condensation temperature.

This will be described with reference to FIGS. 2 and 3.

When the heat storage dedicated operation is performed, the refrigerant temperature sensor 22 detects the condensation temperature of the refrigerant that has left the heat storage tank 3. At this time, when the compressor 1 is driven by the inverter device 2 and is driven at the maximum frequency of 120 Hz in the normal air conditioning operation, the compressor 1 is stopped due to the breakdown of the motor of the compressor 1 or the rapid rise of the condensation temperature. Since it is easy, the maximum frequency value during dedicated heat storage operation is 90 Hz
The condensing pressure does not rise sharply by operating as, and therefore the amount of heat radiated in the heating heat exchanger 10 of the heat storage tank 3 becomes the optimum amount of heat for heating the heat storage material 12 in the solid state, and the compressor 1 will not be stopped. Further, when it is driven by a commercial power source, its compression capability is sufficiently lower than the compression capability of the maximum frequency value of the inverter device 2, and therefore there is no support even if it is started as it is.

When the dedicated heat storage operation is performed, the temperature of the heat storage material 12 in the heat storage tank 3 gradually rises, and at the same time, the condensation temperature detected by the refrigerant temperature sensor 22 also rises. As shown in FIG. 2, when the condensing temperature reaches 56 ° C., the output frequency value of the inverter device 2 is lowered, and when the condensing temperature drops to 50 ° C., the output frequency is raised. ON when driven by commercial power supply
・ Off control.

This frequency control or ON / OFF control will be described in more detail with reference to FIG.

First, when the heat storage exclusive operation is started, the refrigerant temperature sensor 22 detects the condensation temperature 24 of the refrigerant, compares the detected temperature Tc with a set constant temperature (56 ° C.) 25, and it becomes a certain value or more. If it is, the frequency value is constantly lowered (for example, 10 Hz drop), or if the control is ON / OFF, the compressor 1 is turned OFF 26.
After this frequency drop or the compressor 1 is turned off 26, the timer is set 27, and then the condensing temperature Tc and the set temperature are compared again 28, and if the condensing temperature Tc is still above the set temperature (56 ° C), the frequency value is changed. Lower it further or keep it in the OFF state. When the condensing temperature Tc becomes 50 ° C. or lower and the timer counts up 29 for 3 minutes 29, the frequency is increased again or the compressor 1 is turned on 30, and the above control is repeated thereafter.

In this way, by detecting the condensation temperature of the refrigerant condensed in the heat storage tank 3 and controlling the compressor according to the temperature, stoppage due to breakdown of the compressor is eliminated, and heat storage operation can be optimally performed.

In addition, at the start-up operation at the start of heating, the first two-way valve 6 and the fourth two-way valve 20 are closed, and the second two-way valve 16 and the third two-way valve 18
Is opened, and the refrigerant that is not sufficiently high temperature and high pressure in the compressor 1 is passed through the heating heat exchanger 10 of the heat storage tank 3 to the indoor heat exchanger 5 and condensed there. 2 Through the two-way valve 16 and through the endothermic heat exchanger 11, the heat storage material 12
The third two-way valve 18 of the return line 17
By returning to the compressor 1 via the heat storage tank 3, the heat stored in the heat storage tank 3 is used for heating the circulating refrigerant, thereby improving the heating start-up operation.

Further, when the outdoor heat exchanger 8 is frosted during normal heating and the defrosting operation is performed, the first two-way valve 6 and the third two-way valve 18 are closed, and the second
After opening the two-way valve 16 and the fourth two-way valve 20, the refrigerant condensed in the indoor heat exchanger 5 is passed through the second two-way valve 16 and the heat storage tank 3, and then the fourth two-way direction from the defrost line 19. After flowing through the valve 20 to the outdoor heat exchanger 8, the air is returned to the compressor 1 to defrost the outdoor heat exchanger 8.

When performing the cooling operation, the first to fourth two-way valves 6, 16, 18, 20 are opened and closed in the same manner as the heating operation, and the four-way valve 4 is switched to connect to the port shown by the dotted line in the drawing, and compressed. It suffices to let the refrigerant discharged from the machine 1 flow to the outdoor heat exchanger 8 side in a cycle reverse to that during heating.

Although the heat storage tank 2 is connected in series with the indoor heat exchanger 4 in the above embodiment, the heat storage tank 2 is at a position where heat can be stored in the refrigeration cycle (the discharge side of the compressor 1 and the decompression device 7).
Interval), the discharge refrigerant during heat storage operation may be directly led from the heat storage tank 2 to the pressure reducing device without passing through the indoor heat exchanger 4, and the discharge refrigerant may be discharged to the heat storage tank when using heat storage. May flow to the indoor heat exchanger 4 without flowing, and the heat storage utilization circuit may be configured to flow the condensed refrigerant to the heat storage tank.

[Effect of the Invention] As described above, according to the present invention, the following excellent effects are exhibited.

(1) A heat storage tank that stores the heat of the discharged refrigerant is provided on the discharge side of the compressor, and the condensation temperature of the refrigerant is detected during the heat storage dedicated operation.
By controlling the compressor at that temperature, the compressor can be controlled according to the amount of heat input to the heat storage tank, and optimal heat storage can be performed.

(2) Since the compressor is not stopped due to the breakdown, the reliability of the compressor is improved.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram showing an embodiment of the present invention, and FIG.
FIG. 3 is a diagram for explaining the control of the compressor with respect to the heat storage temperature in the present invention, and FIG. 3 is a flow sheet diagram showing the control of the compressor in the heat storage dedicated operation in the present invention. In the figure, 1 is a variable capacity compressor, 3 is a heat storage tank, 5 is an indoor heat exchanger, 7 is a pressure reducing device, 8 is an outdoor heat exchanger, 22 is a refrigerant temperature sensor, and 23 is an indoor heat exchange temperature sensor.

Claims (1)

[Scope of utility model registration request] 1. A variable capacity compressor, a four-way valve, an indoor heat exchanger,
A decompression device and an outdoor heat exchanger are sequentially connected to form a refrigeration cycle, and a heating heat exchanger through which refrigerant discharged from the compressor passes is connected between the compressor and the four-way valve in the refrigeration cycle. In the air conditioner that accommodates the heating heat exchanger in the heat storage tank, a refrigerant temperature sensor is provided on the refrigerant outlet side of the heating heat exchanger and the indoor heat exchanger that serves as a condenser during the heat storage dedicated operation. Is installed, the maximum operating frequency of the compressor is set lower than the maximum operating frequency of normal heating during the heat storage dedicated operation, the compressor is operated, the indoor fan is stopped, and the temperature detected by the refrigerant temperature sensor is constant. When the value is reached, the discharge refrigerant from the compressor flows into the heating heat exchanger and is condensed, and then the capacity of the variable capacity compressor is reduced so that the condensate flows through the indoor heat exchanger as it is. Characterized by Air conditioner.