JPH0387576A - Air conditioner - Google Patents

Abstract

PURPOSE:To reduce a defrosting operation time by arranging a bypass refrigerant circuit between the outlet side of an indoor side heat exchanger and the inlet side of an outdoor side heat exchanger, accumulating heat with first and second solenoid valves opened and closed and defrosting with the first and second solenoid valves closed and opened, respectively. CONSTITUTION:When first and second solenoid valves 23 and 25 are set to be opened and closed, respectively, in a bypass refrigerant circuit 26, a refrigerant which has passed an indoor side heat exchanger 3 is accumulated in a heat accumulator 24 via the first solenoid valve 23 and a suction tube 27 in the same condition as that of the refrigerant outputted from the indoor side heat exchanger 3. That is, the refrigerant is accumulated at a point A in the condition of a liquid phase refrigerant. The liquid refrigerant at the point A moves on an isotherm represented by a dashed line to be changed to a condition represented in a point B. At this time, a refrigerant gas 1a discharged in a refrigerant circuit and a circuit condition as represented by a full line in a room heating operation is changed to that as represented by a dotted line in a defrosting, operation, a refrigerant gas pressure in a low pressure refrigerant circuit portion being raised. As a result, a low pressure at a temperature below 0 deg.C is increased to the pressure at a temperature above 0 deg.C and frost attached to an outdoor heat exchanger 5 is molten to be removed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an air conditioner, and more particularly to a heat pump type air conditioner equipped with a heat storage device.

[Prior art]

Figures 4 and 5 are cross-sectional views of a refrigerant circuit, an electric control circuit during defrosting, and a heat storage type exchanger of a conventional air conditioner disclosed in, for example, Japanese Unexamined Patent Publication No. 61-165560. It is. In Fig. 4, l is a compressor that compresses and discharges refrigerant, 2 is a four-way valve that switches the suction/discharge system of compressor 1, 3 is an indoor heat exchanger, and 4 is a mechanical expansion valve as a pressure reducing device. , 5 is an outdoor heat exchanger. And these compression if, four-way valve 2. Indoor heat exchanger 39 mechanical expansion valve 4. The outdoor heat exchanger 5 constitutes a refrigerant circuit 7 by being connected in an annular manner by a refrigerant pipe 6 and through which refrigerant flows. 8 is an indoor fan that performs heat exchange by forcing air into the indoor heat exchanger 3; 9 is an outdoor fan that performs heat exchange by forcing air into the outdoor heat exchanger 5; 10 is an outdoor heat exchanger 5 is a defrosting condition detector equipped with a temperature-sensing part on the inlet side; 11 is a temperature-sensing cylinder for detecting the refrigerant temperature at the suction part of the compressor 1; and 12 is a defrosting condition detector for detecting the refrigerant pressure at the suction part of the compressor 1. This is a pressure equalizing tube for detection. By controlling the throttle of the mechanical expansion valve 4, the temperature sensing tube 11 and the pressure equalizing tube 12 control the degree of heating in these portions to a constant value. Further, the temperature sensing cylinder 11 and the pressure equalizing pipe 12 control the mechanical expansion valve 4 to be fully closed when the compressor 1 is stopped and when the suction refrigerant is liquefied. 13 is a heat storage maximum heat exchanger that stores the heat required during defrosting, 14 is a first solenoid valve,
15 is a second solenoid valve; 16 is a refrigerant discharge port 1a of the compressor 1;
A first bypass circuit connected to the inlet of the outdoor heat exchanger 5 through the heat storage maximum heat exchanger 13 and the first solenoid valve 14; 17 is a part of the refrigerant in the first bypass circuit 16; The refrigerant pipe 17 has a structure in which a heat storage maximum heat exchanger 13 is disposed surrounding the refrigerant pipe 17. That is, as shown in the cross-sectional view of FIG. 5, the heat storage maximum heat exchanger 13 has fins 18 fixed around the refrigerant pipe 17 to improve heat exchange. And this fin 1
The outer periphery of the outer shell 8 is covered with an outer shell 19 in a airtight state, and the inside thereof is filled with a heat storage material 20. 21 is a second bypass circuit extending from the outlet side of the heat storage maximum heat exchanger 13 to the outlet side of the indoor heat exchanger 3 via the second solenoid valve 15;
As shown in FIG. 5, 22 is a heat storage condition detector that is fixed in contact with the outer shell of the heat storage heat exchanger 13, and has a contact that opens when the temperature of the heat storage heat exchanger 13 rises above a set temperature. are doing. Next, the operation of the air conditioner with the above configuration will be explained. First, when starting the heating operation, the four-way valve 2 is switched to the illustrated heating cycle operation mode. On the other hand, at the start of heating, the defrosting condition detector 10 and the heat storage condition detector 2
Since both of the valves 1 and 2 do not output a detection signal, a control circuit (not shown) sets only the second magnetic valve 15 to an open state. Next, when the compressor m machine 1 is operated, the high temperature and high pressure refrigerant gas discharged from the refrigerant discharge port 1a of the compressor 1 is
It is supplied to the indoor heat exchanger 3 via the four-way valve 2 as shown by the arrow in the figure. In the indoor heat exchanger 3, the high temperature and high pressure refrigerant gas is cooled by forced ventilation supplied from the indoor fan 8.
It becomes a condensate by being cooled through heat exchange within the tank. The refrigerant liquid condensed in this way is adiabatically expanded when passing through the mechanical expansion valve 4 and becomes a low-pressure refrigerant, and is heated and evaporated by forced ventilation by the outdoor fan 9 in the outdoor heat exchanger 5. It becomes low pressure refrigerant gas. This low-pressure refrigerant gas is sucked into the compressor 1 via the four-way valve 2, where it is compressed again and discharged as high-temperature and high-pressure refrigerant. On the other hand, since the second bypass circuit 21 is configured by the heat storage maximum heat exchanger 13 and the second 11 and the magnetic valve 15, a part of the high temperature and high pressure refrigerant discharged from the compressor 1 is transferred to the second bypass circuit 21. The refrigerant flows through the refrigerant piping 17 that constitutes the bypass circuit 21 . When the high-temperature, high-pressure refrigerant flows through the refrigerant pipe 17, the heat of this high-temperature, high-pressure refrigerant is exchanged with the heat storage material 20 via the fins 18 that constitute the heat storage maximum heat exchanger 13.
Heat is stored inside the heat storage maximum heat exchanger 13. The refrigerant heat-exchanged in this heat storage heat exchanger 13 is supplied to the outlet side of the indoor heat exchanger 3 via the second solenoid valve 5, thereby joining the main refrigerant pipe 6. ,
Thereafter, it is returned to the compressor 1 via the main refrigerant circuit 7. Here, heat storage in the heat storage maximum heat exchanger 13 progresses, and the outer shell 19
When the temperature reaches the set temperature, the heat storage condition detector 22 opens a contact provided therein to supply a detection signal to a control section (not shown). When the control unit receives the detection signal from the heat storage condition detector 22, it controls the second solenoid valve 1.
By closing 5, the second bypass refrigerant circuit 21 is closed. Therefore, when the heat storage in the heat storage maximum heat exchanger 13 is completed, the refrigerant flows only through the main refrigerant circuit 7, and heating operation is performed. Next, when the outside air temperature decreases and icing begins to form on the outdoor heat exchanger 5, the ability to absorb heat from the outside air decreases, so the input pipe temperature of the outdoor heat exchanger 5 decreases. The defrosting condition detector 10 detects this and supplies it to a control section (not shown). When the control unit receives the defrosting condition detection signal supplied from the defrosting condition detector 10, it switches to the defrosting operation mode. In this defrosting operation mode, the first solenoid valve 14 is opened, so a first bypass refrigerant circuit 16 is formed. Then, the high temperature and high pressure refrigerant gas discharged from the compressor 1 flows through this first bypass refrigerant circuit 1.
6 to the outdoor heat exchanger 5, the frost adhering to the outdoor heat exchanger 5 is thawed. Here, when the defrosting operation mode proceeds, the temperature of the refrigerant gas sucked into the compressor 1 becomes low because the amount of heat exchanged in the outdoor heat exchanger 5 is extremely large. As the temperature of the refrigerant gas being sucked decreases, the temperature of the refrigerant gas discharged from the compressor 1 and flowing into the first bypass refrigerant circuit 16 also decreases accordingly. However, heat storage form exchanger 1
3 provides thermal energy stored during heating operation to the refrigerant gas passing through the inside of the heat storage type exchanger 13 through heat exchange, so that the outdoor heat exchanger 5 is continuously supplied with high-temperature refrigerant gas. , effective defrosting will be performed.

[Problem to be solved by the invention]

Conventional air conditioners are configured as described above.
1st. Since a second refrigerant bypass circuit is required,
The refrigerant circuit becomes complicated and expensive. In addition, in the above configuration, heat is stored indirectly in the heat storage material through heat exchange, so the heat storage efficiency is low and the defrosting operation time becomes long. Since refrigerant gas no longer flows to the indoor heat exchanger 3 during frost operation, heating is interrupted, causing discomfort. This invention was made to solve the above-mentioned problems, and while the configuration of the refrigerant circuit is simple, the defrosting operation time can be shortened, and the defrosting operation does not cause discomfort. There is no air conditioner provided.

[Means to solve the problem]

The air conditioner according to the present invention configures a bypass refrigerant circuit by connecting in series a first solenoid valve, a heat storage device that stores refrigerant in a liquid state, and a second solenoid valve. is placed between the outlet side of the indoor heat exchanger and the inlet side of the outdoor heat exchanger, the first solenoid valve is opened, and the second t
Heat is stored by closing the magnetic valve, and defrosting is performed by closing the first solenoid valve and opening the second solenoid valve.

[Effect]

In the air conditioner according to the present invention, defrosting can be performed without interrupting heating operation by supplying the refrigerant stored in the heat storage device in a high temperature, high pressure liquid state to the outdoor heat exchanger. .

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows a refrigerant circuit showing an embodiment of the air conditioner according to the present invention, and since 1 to 9 are the same as those in FIG. 4, detailed explanation thereof will be omitted. 23 is a first electromagnetic valve; 24 is a heat storage device that stores heat by storing high-temperature, high-pressure refrigerant in liquid form;
Reference numeral 25 denotes a second solenoid valve, which constitutes a bypass refrigerant circuit 26 by being connected in series, and connects the outlet side of the indoor heat exchanger 3 and the outdoor @ heat exchanger 50 inlet side. connected between. FIG. 2 is a sectional view of the heat storage device 24, in which a heat storage agent 24b is housed inside the outer shell 24a so that heat can be exchanged directly with the refrigerant. Here, the heat storage agent 24b is covered with resin or the like so as not to mix with the refrigerant. Also, inside this heat storage device 24, there is a suction pipe 27 connected to the first solenoid valve 23 and extending to near the bottom, and a discharge pipe 28 connected to the second solenoid valve 25 and terminating at the ceiling. is provided. Next, the operation of the air machine configured as described above will be explained. In the refrigerant circuit shown in Fig. 1, the flow of refrigerant discharged from the compressor 1 during heating operation and sucked into the compressor 1 again via the refrigerant circuit is the same flow as in the conventional case, as shown by the arrow. . At this time, the first solenoid valve 2 in the bypass refrigerant circuit 26
3 is opened and the second solenoid valve 25 is set to close, the refrigerant that has passed through the indoor heat exchanger 3 enters the heat storage device 24 via the first solenoid valve 23 and the suction pipe 27, and generates indoor heat. The refrigerant is stored under the same conditions as the refrigerant output from the exchanger 3. In other words, the refrigerant is stored in a liquid state at point A on the Mollier diagram shown in FIG. Next, to perform defrosting operation, close the first solenoid valve 23,
Also, the second solenoid valve 25 is set to open. Then, the pressure inside the heat storage device 24 is reduced to the discharge pipe 28. The pressure becomes the same as that at the outlet of the outdoor heat exchanger 5 via the second solenoid valve 25 . As a result, the liquid refrigerant stored in the heat storage device 24 has a low pressure and evaporates into refrigerant gas. Here, if the melting point of the heat storage agent 24b is set at point A on the Mollier diagram as shown in FIG.
When the liquid refrigerant inside changes into refrigerant gas, it takes away the latent heat of vaporization from the heat storage agent 24b, so even if the liquid refrigerant changes into refrigerant gas, no temperature change occurs. This is because the latent heat of vaporization required when the refrigerant changes from liquid to gas is taken away from the heat storage agent 24b, and when the refrigerant changes from liquid to gas, the heat storage agent 24b changes from liquid to solid and retains it. This is to transfer heat to the refrigerant gas. That is, in the Mollier diagram shown in FIG. 3, the liquid refrigerant that was at point A moves on the isothermal line on the - dotted chain line and changes its state to point B. At this time, refrigerant gas is released into the refrigerant circuit, and the circuit state shown by the solid line during heating operation changes to the circuit state shown by the dotted line during defrosting operation, and the refrigerant gas pressure in the low-pressure refrigerant circuit increases. do. As a result, the low pressure (above the solid line), which was below 0°C (below the two-dot chain line), becomes more than O'C (above the two-dot chain line), and the frost adhering to the outdoor heat exchanger 5 is melted. will be removed. On the other hand, by closing the first electromagnetic valve 23, the refrigerant flowing through the high-pressure refrigerant circuit is prevented from flowing into the heat storage device 24, so the refrigerant pressure within the high-pressure refrigerant circuit during the defrosting operation does not change at all. There is no change, and the heating operation continues as is. In other words,
Defrosting can be performed while heating operation continues. The melting point (the point at which it changes from liquid to solid) of the heat storage agent 24b may be set to a temperature slightly lower than the temperature of the refrigerant at the outlet side of the indoor heat exchanger 3. Specifically, it is best to select one with a melting point of 20 to 50°C.

【Effect of the invention】

As explained above, according to the present invention, the first electromagnetic valve, the heat storage device that stores the refrigerant in a liquid state together with the heat storage agent, and the second
A bypass refrigerant circuit is constructed by connecting the solenoid valves in series, and this bypass refrigerant circuit is arranged between the outlet side of the indoor heat exchanger and the inlet side of the outdoor heat exchanger.
Open the solenoid valve. Since the second solenoid valve is closed to store heat, the first solenoid valve is closed, and the second solenoid valve is opened to defrost the defrost. Since frosting is possible, the unpleasant feeling of interruption of heating operation during defrosting, which conventionally occurs, can be prevented. In addition, since the bypass refrigerant circuit is only provided between the outlet side of the indoor heat exchanger and the inlet side of the outdoor heat exchanger, the refrigerant circuit is significantly simplified compared to conventional methods. It has various effects.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram showing an air conditioner according to an embodiment of the present invention, FIG. 2 is a sectional view of the heat storage device shown in FIG. 1, and FIG.
The figure is a Mollier diagram, FIG. 4 is a refrigerant circuit diagram showing a conventional air conditioner, and FIG. 5 is a sectional view of the heat storage device shown in FIG. 4. 1... Compressor, 2... Four-way valve, 3... Indoor heat exchanger, 4... Pressure reducing device (mechanical expansion valve), 5... Outdoor heat exchanger, 7... - Refrigerant circuit, 23... First solenoid valve, 24... Regenerator, 25... First 11t solenoid valve, 26... Bypass refrigerant circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In an air conditioner equipped with a compressor, a four-way valve, an indoor heat exchanger, a pressure reduction device, and an outdoor heat exchanger, an inlet pipe having a first electromagnetic valve, a heat storage device containing a heat storage agent, and a second electromagnetic valve are provided. A heat storage circuit in which discharge pipes each having a valve are connected in series is connected in parallel to the pressure reducing device so as to store liquid refrigerant during heating operation, and heating is performed by opening the first solenoid valve and closing the second solenoid valve. An air conditioner characterized in that a heat storage operation is performed, the first solenoid valve is closed, and the second solenoid valve is opened to perform a defrosting operation while performing a heating operation.