JPS6355631B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to an air-cooled heat pump type air conditioner, specifically a compressor, a four-way switching valve, an indoor heat exchanger that serves as an evaporator during cooling and a condenser during heating, and a condenser during cooling and serves as a condenser during heating. Equipped with an outdoor heat exchanger that serves as an evaporator,
The present invention relates to an air-cooled heat pump air conditioner capable of heating and cooling by switching the four-way switching valve.

Conventionally, in an air conditioner configured as described above, when the outdoor heat exchanger serving as the evaporator becomes frosted during heating operation, the heating operation is stopped using an electric heater and defrosted, or the four-way switching valve is switched, The refrigeration cycle is switched to the cooling cycle for defrosting.

However, with the conventional defrost method as described above,
Since heating operation is stopped or switched to cooling operation, heating capacity cannot be obtained during defrosting, causing the room temperature to drop. In particular, with the defrost method that uses a reverse cycle, heat is absorbed from the room and defrost is performed using that heat, resulting in a significant drop in room temperature.Furthermore, cold air is blown out from the indoor heat exchanger, causing discomfort to the occupants. Furthermore, since the refrigeration cycle is reversed and switched to the cooling cycle,
During defrosting, the outdoor heat exchanger becomes high-pressure, and liquid refrigerant accumulates in this outdoor heat exchanger. When switching to heating operation again after defrosting, a large amount of liquid refrigerant is sucked into the compressor. There was also the problem of pressure fluctuations occurring in various parts when switching the refrigeration cycle, and the problem of noise generation due to reverse flow of refrigerant.

On the other hand, the outdoor heat exchanger is divided into two parts, one of these outdoor heat exchangers is used as a condenser, and the other is used as an evaporator, and the heat absorbed by one of the outdoor heat exchangers that serves as the evaporator is used to alternately defrost. However, according to this method, the heat exchanger that serves as the heat source during defrosting is half the size of the outdoor heat exchanger, and
The heat pumped up by the heat exchanger will be used for heating as well as defrosting, so not only will the heating capacity be less than half, but sufficient heat for defrosting will not be obtained, and the defrosting time will become longer. In addition, the refrigerant circuit becomes complicated and control equipment is required, resulting in high costs, and the above-mentioned problems of the reverse cycle system cannot be fundamentally solved.

The present invention was invented in view of the above-mentioned conventional problems.The main purpose of the present invention is to provide air that can be defrosted in a short time using a sufficient heat source, while providing the same heating capacity during defrosting as during heating operation. Another object of the present invention is to provide an energy-efficient air conditioner that can further shorten the defrost time while improving the capacity of the compressor during defrosting and eliminating the reduction in heating capacity. It is in the point of doing.

That is, in the present invention, a heat storage tank is provided to store heat during heating operation, and during defrosting, the heat is used as a heat source so that defrosting can be performed while heating operation is being performed. A built-in heat storage tank is formed, and the heat storage tank is equipped with a first heat exchanger that heats the heat storage agent and a second heat exchanger that absorbs heat from the heat storage agent, and the first heat exchanger is ,
In addition to providing a means for connecting to a pipe that is at high pressure during heating and allowing refrigerant to flow through the first heat exchanger during heating and defrosting, the expansion mechanism for heating is bypassed to the liquid pipe through which high-pressure liquid refrigerant flows during heating. A bypass pipe is provided, and the second heat exchanger is connected in the middle of this bypass pipe, and the bypass pipe is opened during defrosting, while an evaporator and an evaporator during defrosting are connected to the suction pipe of the compressor. This is characterized by the interposition of a third heat exchanger.

Embodiments of the air conditioner of the present invention will be described below based on the drawings.

In the drawing, 1 is a compressor, 2 is a four-way switching valve,
3 is an indoor heat exchanger, 4 is an outdoor heat exchanger, 5 is an expansion mechanism for cooling, 6 is an expansion mechanism for heating, 7 is a check valve connected in parallel with the expansion mechanism 5 for cooling, and 8 is the heating expansion mechanism. a check valve connected in parallel with the expansion mechanism 6;
is an accumulator, and these refrigeration devices are connected by refrigerant piping 10, and by switching the four-way switching valve 2 as shown by the dotted line, a refrigeration cycle shown by the solid line arrow is formed, and the indoor heat exchanger 3
is used as an evaporator, and the outdoor heat exchanger 4 is used as a condenser for cooling. Also, by switching the four-way switching valve 2 as shown in the solid line, a refrigeration cycle shown by the dotted line arrow is formed, and the indoor heat exchanger 4 is used as an evaporator. 3 is used as a condenser, and the outdoor heat exchanger 4 is used as an evaporator for heating.

Therefore, in the air conditioner of the present invention, in the air conditioner configured as described above, a heat storage tank 11 containing a heat storage agent such as brine is formed, and the heat storage agent is heated in the heat storage tank 11 during heating. A first heat exchanger 12 and a second heat exchanger 13 that absorbs heat from the heat storage agent are installed internally, and the first heat exchanger 12 is connected to pipes 10a and 10b that are at high pressure during heating, and when heating and Means 18, 19, and 24 are provided for flowing refrigerant into the first heat exchanger 12 during defrosting, and a bypass pipe 14 for bypassing the heating expansion mechanism 6 is provided in the liquid pipe 10b through which high-pressure liquid refrigerant flows during heating. Provided,
The second heat exchanger 13 is connected to the middle of the bypass pipe 14 so that the bypass pipe 14 is opened during defrosting, while a third A heat exchanger 15 was inserted.

What is shown in FIG. 1 is the first heat exchanger 12
An inlet pipe 16 is connected to the inlet of the inlet, and an outlet pipe 17 is connected to the outlet of the
The inlet pipe 16 is connected to the gas pipe 10a through which high-pressure gas refrigerant flows during heating, and the outlet pipe 1
7 are respectively connected between the connection position of the inlet pipe 16 and the inlet side of the indoor heat exchanger 3 during heating, and the outlet pipe 17 and the inlet pipe 1
Check valves 18 and 19 are respectively interposed in the gas pipe 10a between the connection position between the gas pipe 10a and the outlet pipe 17, and the bypass pipe 14 is connected to the inlet of the second heat exchanger 13 midway on the inlet side. , a first pressure reducing mechanism 21 consisting of a solenoid valve 20 that opens during defrosting and a capillary reach tube, a fourth heat exchanger 22 that absorbs heat from the heat storage agent, and a second pressure reducing mechanism 23 consisting of a capillary reach tube are moved in the forward direction. Further, two third heat exchangers 15 are provided, one of which is connected to the bypass pipe 14 between the solenoid valve 20 and the first pressure reducing mechanism 21, and the other one is connected to the bypass pipe 14 between the solenoid valve 20 and the first pressure reducing mechanism The fourth heat exchanger 22 and the second pressure reducing mechanism 2
1 and the bypass pipe 14 between the two. Note that 43 is a check valve that allows the refrigerant to flow only from the second heat exchanger 13 to the outdoor heat exchanger 4.

Thus, in the air conditioner shown in FIG. 1, during heating operation, a part of the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 flows into the first heat exchanger 12 installed in the heat storage tank 11. Heat is stored by heating the heat storage agent. This heat storage continues during heating operation, but ends at the heat storage limit of the heat storage agent, and even if the high-pressure gas refrigerant flows to the first heat exchanger 12,
Heat radiation to the heat storage agent is eliminated, and the outlet pipe 17
From there, the gas refrigerant joins with the gas refrigerant flowing through the gas pipe 10a and reaches the indoor heat exchanger 3.

During the heating operation as described above, the outdoor heat exchanger 4 performs evaporation by exchanging heat with outdoor air.
is frosted, the solenoid valve 20 is opened during the heating refrigeration cycle, and the bypass pipe 1 is
4 is opened to defrost.

Therefore, by opening the bypass pipe 14,
High-pressure liquid refrigerant condensed in indoor heat exchanger 3 (50℃)
Almost all of it passes through the bypass pipe 14, and as shown in the Mollier diagram in FIG.
The pressure is reduced by the second pressure reducing mechanisms 21 and 23, and the liquid refrigerant becomes a low-pressure liquid refrigerant. After absorbing heat in the second heat exchanger 13, it flows to the outdoor heat exchanger 4, and the second heat exchanger 13 , the outdoor heat exchanger 4 serves as an evaporator that uses the high-temperature heat storage agent stored in the heat storage tank 11 as a heat source, and performs defrosting, and serves as a low-pressure side condenser, and frosts the outdoor heat exchanger 4. Saturation temperature corresponding to the low pressure side refrigerant pressure above the temperature required to melt frost and ice (e.g. 15℃)
In this way, the frost forming on the outdoor heat exchanger 4 is defrosted.

In addition, during the above-mentioned defrosting, the indoor heat exchanger 3 functions as a high-pressure side condenser through which a high-pressure gas refrigerant flows, and the amount of heat required for defrosting is taken from the heat storage agent. The same heating capacity can be obtained, and the outdoor heat exchanger 4
In this case, the low-pressure liquid refrigerant that radiates heat to the frost and condenses is evaporated in the third heat exchanger 15 and returned to the compressor 1 at a predetermined degree of superheat.

Also, in the Mollier line in Figure 2, I~NU is the first line.
It shows the refrigerant state at the entrance and exit positions of each device shown in the figure, where A is the outlet of the compressor 1, B is the outlet of the indoor heat exchanger 3, C is the inlet of the first pressure reducing mechanism 21, and D is the The inlet of the fourth heat exchanger 22, E is its outlet (25°C), F is the outlet side of the attached part with the third heat exchanger 15, the inlet of the second pressure reduction mechanism 23, and G is its outlet. The inlet of the second heat exchanger 13, the outlet of the second heat exchanger 13; the inlet of the outdoor heat exchanger 4; , which shows the state of each refrigerant at the inlet of the compressor 1.

As described above, defrosting can be performed while performing heating operation using the indoor heat exchanger 3 as a high-pressure side condenser during defrosting, and since the heat necessary for defrosting is used, the heating capacity is equivalent to that during heating operation. In addition, during defrosting, the low pressure increases, so the amount of refrigerant circulation increases, thereby shortening the defrosting time, and since the outdoor heat exchanger 4 is on the low pressure side, this outdoor heat Refrigerant does not accumulate in the exchanger 4.

Therefore, when heating operation is performed after defrosting, a large amount of liquid refrigerant is not sucked into the compressor 1 as in the conventional reverse cycle defrosting system.

Furthermore, since the refrigeration cycle is not switched to a reverse cycle during defrosting, there is almost no pressure fluctuation in each part, and no noise is generated due to pressure fluctuations and reverse flow of refrigerant.

In the embodiment shown in FIG. 1 described above, the inlet pipe 16 and the outlet pipe 17 of the first heat exchanger 12 are connected to the gas pipe 10a, but as shown in FIG. It may be connected to the high pressure liquid pipe 10b between the outlet side of the heat exchanger 3 during heating and the connection position of the outlet bypass pipe 14.

In this case, the outlet pipe 17 is connected to the heat storage tank 11.
A check valve 2 is provided with a solenoid valve 24 that closes due to a rise in internal temperature and prevents backflow to the outlet pipe 17.
5 and a capillary reach tube 2
6 is inserted. The pressure reducing mechanism 26 is set so that the flow rate can be adjusted so that, for example, 10% of the total amount of high-pressure gas refrigerant flows.

In the configuration shown in FIG. 1, a short-circuit pipe 27 is provided between the inlet pipe 16 and the outlet pipe 17 as shown by a dashed line, and the temperature inside the heat storage tank 11 is connected to the short-circuit pipe 27. A solenoid valve 28 may be provided that opens when raised.

Further, in the embodiment shown in FIGS. 1 and 2, the third heat exchanger 15 is attached to the bypass pipe 14 and exchanges heat with the liquid refrigerant passing through the bypass pipe 14. As shown in the figure, it may be installed inside the heat storage tank 11, or it may be attached to the inlet pipe 16 connected to the gas pipe 10a.

The one shown in FIG. 5 is another embodiment, and the difference from the one in FIG. 1 is that the third heat exchanger 1
5 is reduced to one, the first and second pressure reducing mechanisms 21,
23 into one pressure reducing mechanism 48, and the cooling expansion mechanism 5 and the heating expansion mechanism 6 are partially combined, that is, the reference numeral 47 is a pressure reduction mechanism for both cooling and heating, and the reference numeral 45 is a heating Note that 43 and 46 are check valves, and 44 is a heater for heating the refrigerant provided in the middle of the indoor heat exchanger 3. Further, the solenoid valve 28 is opened during defrosting.

FIG. 6 is a Mollier diagram during defrosting of the example shown in FIG. 5, and will be described with reference to FIG.

Here, the heat storage tank 11 already has about 80
Suppose brine is stored at ℃.

During defrosting, the high-pressure gas refrigerant (105° C.) discharged from the compressor 1 flows into the indoor heat exchanger 3 through the short-circuit pipe 27 and is condensed to provide heating. Here, the condensed liquid refrigerant (46°C) is heated by the refrigerant heating heater 44.
After being heated in
The pressure is reduced in the second heat exchanger 13 and evaporated (10°C).
Then, it is further heated (40℃). This refrigerant flows into the outdoor heat exchanger 4 through the check valve 43 and defrosts the outdoor heat exchanger 4. The refrigerant condensed here is heated in the third heat exchanger 15, becomes a gas refrigerant, and returns to the compressor 1. As shown in FIG. 5, using one third heat exchanger 15 has the advantage of simplifying the refrigerant piping.

In addition to the above-described configuration, the device of the present invention also has a gas-liquid separator 30 interposed in the middle of the bypass pipe 14, as shown in FIG. A pressure reducing mechanism 32, 33 consisting of a capillary reach tube or the like is interposed in the injection extraction pipe 31, and the injection extraction pipe 31 is connected to the compressor 1 as shown in FIG.
It may also be connected to the cylinder 1a during the compression process. In FIG. 9, reference numeral 1b indicates a piston, which is in a state slightly elevated from the bottom dead center, and gas refrigerant at an intermediate pressure is taken in from the injection exit pipe 31. Also 10a
is the discharge pipe.

With the above configuration, during defrosting, the capacity of the compressor 1 can be increased to, for example, 130% because it can partially suck in the gas refrigerant with a small specific volume at intermediate pressure, while reducing the heating capacity. This allows you to defrost in a short amount of time while still allowing heating operation without having to do anything.

That is, to explain using the Mollier diagram shown in FIG. 10, during defrosting, the high-pressure gas refrigerant I discharged from the compressor 1 is condensed in the indoor heat exchanger 3, then enters the gas-liquid separator 30, where it is Separated into liquid gas. Here, the gas tube is the injection tube 31
The pressure is reduced by the pressure reducing mechanisms 32 and 33, and the gas is sucked into the compressor 1, where it is mixed with the gas sucked in from the suction pipe 10c and compressed. Since this gas has an intermediate pressure, which is higher than the pressure of the suction pipe 10c, its specific volume is small, and therefore the amount of refrigerant circulation increases and the compression function increases. In addition, outdoor heat exchanger 4
Since the defrost is the same as in FIG. 2, the explanation will be omitted.

In the configuration shown in FIG. 7, the high pressure liquid pipe 10b
A gas-liquid separator 34 is also provided in the gas-liquid separator 34, and the gas region of this separator 34 is connected to the injection exit pipe 31 through a check valve 3.
5, heating capacity can be improved during heating operation.

In this case, a pressure reducing mechanism is provided at the connection between the gas-liquid separator 34 and the injection tube 31, or check valves 7 and 8 are connected in parallel with the expansion mechanisms 5 and 6 as shown in FIG. Decompression mechanism 3 in series with
6, 37 are provided, and the separator 34 is interposed in the low pressure liquid pipe 10e between these pressure reducing mechanisms 36, 37.

Further, the injection tube 31 may be provided with a solenoid valve 38 that opens only when it is necessary to improve the performance.

Furthermore, as shown in FIG. 8, the gas pipe 10a,
A short-circuit gas pipe 40 is provided between the bypass pipe 14 and the inlet side of the gas-liquid separator 30, and the third heat exchanger 15 is attached to the short-circuit gas pipe 40. The heat exchanger 4 may heat the condensed low-pressure liquid refrigerant, and the increased capacity due to injection from the injection tube 31 may be used to heat the suction refrigerant. In this case, a pressure reducing mechanism 41 such as a capillary reach tube is interposed in the short-circuit gas pipe 40 from the part attached to the third heat exchanger 15 to the side connected to the gas-liquid separator 30, and A solenoid valve 42 that opens during defrosting is provided.

As described above, in the present invention, the heat storage tank 11 is provided, heat is stored in the heat storage tank 11 during heating operation, and during defrosting, the heat stored in the heat storage tank 11 is used as a heat source for defrosting, so that the refrigeration cycle is Defrosting can be performed while heating operation is performed without switching to the reverse cycle, and heating can be performed with the same capacity as heating operation during defrost, so the room temperature does not drop and cold air is blown from the indoor heat exchanger 3. This allows defrosting to be carried out without the occupants noticing. In addition, since defrosting is performed using the stored heat, a sufficient amount of heat can be obtained during defrosting, and the defrosting time can be shortened.

In addition, an outdoor heat exchanger 4 that performs defrosting
In contrast to the reverse cycle defrost method in which high pressure gas is supplied by switching to the reverse cycle, the refrigerant does not accumulate in the outdoor heat exchanger 4 because it functions as a low pressure side condenser and performs defrost. Therefore, even if the heating operation is resumed after the defrosting operation is completed, a large amount of liquid refrigerant will not be sucked into the compressor 1.

Furthermore, unlike the reverse cycle defrost method, defrosting is performed without switching the refrigeration cycle, so there is almost no pressure fluctuation in each part of the refrigerant circuit, and there is no problem of noise generation due to pressure fluctuations and reverse refrigerant flow. Yes, and compared to the conventional method in which the outdoor heat exchanger is divided and heat exchanged alternately, the refrigerant circuit structure is simpler, there is no need to use special control equipment, and there is no need for high costs. It is.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant piping system diagram showing one embodiment of the air conditioner of the present invention, Fig. 2 is a Mollier diagram showing the refrigerant state during defrosting by the air conditioner of Fig. 1, and Figs. The figure is a refrigerant piping system diagram showing another embodiment, and FIG. 6 is a Mollier diagram showing the state of the refrigerant during defrosting by the air conditioner of FIG.
7 and 8 are refrigerant piping system diagrams showing yet another embodiment, FIG. 9 is a schematic explanatory diagram showing an example of a compressor used in the embodiments of FIGS. 7 and 8, and FIG. FIG. 3 is a Mollier diagram showing the refrigerant state during defrosting by the air conditioner of FIG. 1... Compressor, 2... Four-way switching valve, 3... Indoor heat exchanger, 4... Outdoor heat exchanger, 5... Expansion mechanism for cooling, 6... Expansion mechanism for heating, 10a... Gas Pipe, 10b... Liquid pipe, 11... Heat storage tank, 12...
First heat exchanger, 13... Second heat exchanger, 14...
Bypass pipe, 15... Third heat exchanger, 18... Check valve, 19... Check valve, 20... Solenoid valve, 24...
... Solenoid valve, 30 ... Gas-liquid separator, 31 ... Injection tube, 32, 33 ... Pressure reduction mechanism.

Claims (1)

[Scope of Claims] 1. Compressor 1, four-way switching valve 2, indoor heat exchanger 3 that functions as an evaporator during cooling and a condenser during heating, and an outdoor heat exchanger that functions as a condenser during cooling and an evaporator during heating. In an air-cooled heat pump type air conditioner equipped with a container 4, an expansion mechanism 5 for cooling, and an expansion mechanism 6 for heating,
A heat storage tank 11 containing a heat storage agent is formed, and a first heat exchanger 12 for heating the heat storage agent is provided in the heat storage tank 11.
and a second heat exchanger 13 that absorbs heat from the heat storage agent, and the first heat exchanger 12 is connected to the pipes 10a and 10b that are at high pressure during heating, and the 1 heat exchanger 12 is provided with means 18, 19, and 24 for flowing a refrigerant, and the expansion mechanism 6 for heating is provided in the liquid pipe 10b through which high-pressure liquid refrigerant flows during heating.
A bypass pipe 14 is provided, and the second heat exchanger 13 is connected in the middle of this bypass pipe 14, and the bypass pipe 14 is opened during defrosting, while the suction pipe of the compressor 1 An air-cooled heat pump type air conditioner characterized in that a third heat exchanger 15 serving as an evaporator during defrosting is interposed in 10c. 2. The inlet pipe 16 connected to the inlet of the first heat exchanger 12 installed in the heat storage tank 11 is connected to the gas pipe 10a through which high-pressure gas refrigerant flows during heating, and the outlet pipe 17 connected to the outlet is connected to the inlet pipe 16. The air-cooled heat pump type air conditioner according to claim 1, wherein the air-cooled heat pump type air conditioner is connected between the connection position of the indoor heat exchanger 3 and the inlet side of the indoor heat exchanger 3 during heating. 3. The inlet pipe 16 connected to the inlet of the first heat exchanger 12 installed inside the heat storage tank 11 is connected to the gas pipe 10a through which high-pressure gas flows during heating, and the outlet pipe 17 connected to the outlet of the indoor heat exchanger 3 is connected to the gas pipe 10a through which high-pressure gas flows during heating. High pressure liquid pipe 1 between the outlet side and the connection position of the bypass pipe 14 during heating
The air-cooled heat pump type air conditioner according to claim 1, characterized in that the air-cooled heat pump type air conditioner is connected to 0b. 4. The air cooling system according to claim 1, 2, or 3, characterized in that a third heat exchanger 15 interposed in the middle of the suction pipe 10c is attached in the middle of the bypass pipe 14. Heat pump type air conditioner. 5. The air-cooled heat pump type according to claim 1, 2, or 3, characterized in that the third heat exchanger 15 interposed in the middle of the suction pipe 10c is installed inside the heat storage tank 11. Air conditioner. 6. A gas-liquid separator 30 is interposed in the middle of the bypass pipe 14, an injection extraction pipe 31 is connected to the gas region of the separator 30, and pressure reducing mechanisms 32 and 33 are interposed in the injection extraction pipe 31. With,
6. The air-cooled heat pump type air conditioner according to any one of claims 1 to 5, wherein the injection extension pipe 31 is connected to the compressor 1 during the compression process.