JPH086951B2 - air conditioner - Google Patents

Description

Description: [Object of the invention] (Field of industrial application) The present invention relates to an air conditioner in which a heat storage tank is incorporated in a refrigeration cycle, and in particular, when storing heat in the heat storage tank, the heat storage can be performed quickly. 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, the heat storage material in the heat storage tank is heated by the refrigerant discharged from the compressor to store heat when the air conditioning operation is not performed.

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.

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, in the heat storage-only operation, when the compressor is driven in a low frequency range, the temperature difference between the condensation temperature and the heat storage temperature of the refrigerant in the heat storage layer is small, and therefore the heat storage There is a problem that it takes a long time and the heat storage tends to be insufficient.

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 that can quickly store heat when storing heat in a heat storage tank.

[Structure of the Invention] (Means and Actions for Solving Problems) In order to achieve the above object, the present invention sequentially connects a variable capacity compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger. To form a refrigeration cycle, and in an air conditioner provided with a heat storage tank for storing the heat of the high temperature side refrigerant of the refrigeration cycle, the indoor fan is stopped and the outdoor fan is driven during the heat storage operation, and the variable capacity compressor is further used. And a means for controlling the minimum capacity of the inverter to be higher than the minimum capacity during normal air conditioning operation.
When performing heating operation at ~ 120Hz, 50 ~ 1 during heat storage exclusive operation
By performing the operation in the frequency range of 20Hz, the capacity of the variable capacity compressor is increased, and the heat storage material of the heat storage tank can store heat well.

(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 refrigeration cycle of an air conditioner according to the present invention. In the figure, reference numeral 1 is a variable capacity compressor driven by an inverter device 2, 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.

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.

The indoor heat exchanger 5 is provided between the indoor heat exchanger 5 and the first two-way valve 6.
A heat storage utilization line 15 for flowing the condensed refrigerant from the heat storage tank 3 to the endothermic heat exchanger 11 is connected to the second two-way valve 16
Is connected. The heat absorption heat exchanger 11 has a heat storage utilization line.
A return line 17 for returning the refrigerant from 15 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 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. As shown in the figure, the frequency operation range during normal heating or heating storage operation to be described later is 30 to 120 Hz, and the operation range during dedicated heat storage operation is 50 to 120 Hz, that is, the minimum capacity during heat storage is The compressor 1 is driven so that the capacity becomes higher than the minimum capacity during normal air conditioning operation.

 Next, the operation of this embodiment will be described.

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

During normal heating, the high-temperature high-pressure refrigerant from the variable capacity compressor 1 passes through the heating heat exchanger 10 of the heat storage tank 3 as it is, and the four-way valve 4
Through one port to the indoor heat exchanger 5, where it is condensed by heat exchange with the indoor air that is sucked and blown by the indoor fan 13 and decompressed by the decompression device 7 through the first two-way valve 6. After that, it flows to the outdoor heat exchanger 8 and the outdoor fan there.
The heat is exchanged with the outside air blown in 14 to be evaporated and returned 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.

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 not yet sufficiently stored, and the high temperature high pressure refrigerant from the compressor 1 is discharged. After heating the heat storage material 12 with part of the heat, the indoor heat exchanger 5
It will flow to.

Inverter device 2 during normal heating and heating heat storage operation
The output frequency range of is operated in the range of 30 to 120Hz. 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 dedicated operation is performed, 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 and 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 1-two-way valve 6, evaporated by the outdoor heat exchanger 8, and returned to the compressor 1 through the 4-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 so that the heat storage material 12
Will be heated and the heat will be stored.

At the start of the heat storage dedicated operation, the heat storage material 12 is in the solid state and the temperature difference between the temperature at the start of heat storage and the heat storage temperature (about 50 ° C) is large, so the output frequency value of the inverter device 2 is the maximum value (120 Hz). ), The compressor 1 is driven. At this time, although not shown in the figure, a heat storage tank 3 is provided with a condensation temperature sensor on the refrigerant outlet side, and the output frequency is maximized in accordance with the temperature detected by the sensor to drive the compressor 1 to store heat. The material 12 can be melted quickly and can be stored as latent heat.

Further, as described above, the heat storage material 12 is in a solid state, the heat exchange rate in the heating heat exchanger 10 is low, and the refrigerant heat amount is sufficiently large with respect to the heat radiation amount, the condensation temperature of the refrigerant rises, Since the protection circuit (not shown) of the compressor 1 works, the condensation temperature on the outlet side is detected as described above, and the frequency is appropriately set to 50Hz from the maximum frequency (120Hz) so that the condensation temperature does not rise above a certain value.
You should drop it to.

After starting heat storage only, the output frequency of the inverter device 2 is
As shown in FIG. 4, as the temperature of the heat storage material 12 rises,
If the temperature of the heat storage material 12 is reduced from 120 Hz to 50 Hz and the temperature of the heat storage material 12 reaches the heat storage set temperature, the compressor 1 is stopped, and if the temperature of the heat storage material 12 decreases afterwards due to heat radiation, etc. Machine 1 is driven.

 FIG. 3 shows another embodiment of the present invention.

The temperature of the heat storage material 12 in the heat storage tank 3 at the start of heat storage varies depending on the outside air temperature. In this example, when the outside temperature is high, the output frequency is operated at low Hz, and when the outside temperature is low, the output frequency is operated at high Hz.

First, when the heat storage operation command 21 is issued, the outside air temperature T is detected by the outside air temperature sensor, the outside air temperature T is compared with the set temperature (0 ° C.) 22, and when the outside air temperature T is 0 ° C. or less, The heat storage operation described above is performed, and when the outside air temperature T is 0 ° C. or higher, the heat storage operation 23 of low Hz with the maximum frequency value (120 Hz) lowered is performed.

By controlling the output frequency value according to the outside air temperature in this way, energy saving operation becomes possible during heat storage when the outside air temperature is high.

During the rising 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 are closed.
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.

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 two-way valve 16 and the fourth two-way valve are closed. After opening 20 and passing the refrigerant condensed in the indoor heat exchanger 5 through the second two-way valve 16 and the heat storage tank 3, the outdoor heat exchanger 8 from the defrost line 19 through the fourth two-way valve 20. Then, it 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.

In the above embodiment, the heat storage tank 2 is replaced by the indoor heat exchanger 4.
Although an example in which the heat storage tank 2 is connected in series is shown, 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.

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

(1) A heat storage tank for storing the heat of the discharged refrigerant is provided on the discharge side of the compressor, and the compressor is driven at a frequency value higher than the minimum output frequency of the inverter device during normal air conditioning during dedicated heat storage operation. Therefore, heat can be stored quickly.

(2) Even if the outside air temperature is low, the heat storage operation can be performed accordingly, and sufficient heat storage can be performed.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram showing an embodiment of the present invention, and FIG.
FIG. 4 is a diagram for explaining the operating frequency of the inverter device during normal air conditioning operation and heat storage dedicated operation in the present invention, FIG. 3 is a flow chart showing another embodiment of the present invention, and FIG. 4 is heat storage operation in the present invention. It is a figure which shows the frequency control with respect to the heat storage temperature at the time. In the figure, 1 is a compressor, 2 is an inverter device, 3 is a heat storage tank,
5 is an indoor heat exchanger, 7 is a decompression device, 8 is an outdoor heat exchanger,
13 is an indoor fan, and 14 is an outdoor fan.

Claims (1)

[Claims] 1. A variable capacity compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger are sequentially connected to form a refrigeration cycle, and a heat storage tank for storing the heat of a high temperature side refrigerant of the refrigeration cycle is provided. In the air conditioner, it is provided with means for stopping the indoor fan during heat storage operation and driving the outdoor fan, and further controlling the minimum capacity of the variable capacity compressor to be higher than the minimum capacity during normal air conditioning operation. Air conditioner to be.