KR100386657B1 - Air conditioner - Google Patents

Abstract

The present invention is to provide an air conditioner that can shorten the pressure balance time of the suction and discharge of the stationary compressor.

To this end, the present invention provides two compressors having different compression capacities, a check valve for blocking refrigerant flow into each of the injector discharge ports, an oil separator for recovering oil discharged from the compressor back to the compressor, and a refrigerant. An isothermal condenser and an evaporator for isothermal condensation and isothermal evaporation, an accumulator for allowing only the refrigerant in the gas phase to flow into the inlet of each compressor, first and second discharge pipes connecting the respective compressors and the check valves, and each check An air conditioner including a high pressure pipe connecting a valve and an oil separator, and a suction pipe connecting the evaporator and each accumulator; Pressure equalizing means connected directly to the first and second discharge pipes and the suction pipe to directly communicate the suction and discharge parts of the stopped compressor in a single operation so as to shorten the pressure balance time of the suction and discharge parts of the stopped compressor among the compressors. It provides an air conditioner included.

Description

Air Conditioner

The present invention relates to an air conditioner in which two compressors are installed. More specifically, the pressure equalization of the stopped compressor during a single operation of the compressor is performed in a short time so that the operation of each compressor is performed immediately according to the variation of the indoor load. An air conditioner is provided with a pressure equalization means.

In general, an air conditioner includes a compressor (1) for compressing a refrigerant at a high temperature and a high pressure, a condenser (4) for isothermal condensation of the refrigerant by heat exchange with outdoor air, and a capillary tube (5) as an expansion device for adiabatic expansion of the condensed refrigerant. And an evaporator 6 through which the expanded refrigerant flows through the tube and isothermally evaporates by heat exchange with indoor air.

However, the air conditioner of such a structure controls the cooling and heating temperature of indoor air according to the condition of ambient air temperature and humidity by fully operating the compressor with a certain compression capacity, so that the cooling load of indoor air is small. Compression and phase change of a large amount of refrigerant reduces energy efficiency.

In order to reduce such waste of energy efficiency, an air conditioner equipped with two compressors having different compression capacities that can be operated independently according to indoor load conditions is shown in FIG. 1.

The air conditioner is also comprised of two compressors 1, a condenser 4 for condensing the compressed refrigerant, an expansion valve 5 for expanding the refrigerant, and an evaporator 6 for evaporating the refrigerant. As a result, check valves 11 and 12 for preventing the flow of the refrigerant formed at a high temperature and high pressure through the compressor do not flow back to the compressor.

The oil separator 3 is located between the check valve and the condenser to prevent rotational sliding and overheating of the compressor and to prevent inflow of the refrigeration cycle of the oil, and the oil separated from the oil separator is It is introduced into the suction port of the compressor through the oil return pipe (9, 10).

In order to prevent overload of the compressor, accumulators 7 and 8 are respectively installed at the suction port of the compressor so that liquid refrigerant does not flow into the compressor.

The conventional air conditioner having the above-described configuration has a large compression difference and a relatively low compression capacity than the required indoor cooling load when the cooling load is required because the temperature difference between the indoor air and the ambient air is not so large. By only driving), the refrigerant is compressed.

The compressed refrigerant passes through the oil separator 3 through the first check valve 11, and the refrigerant passing through the oil separator 3 passes through the condenser 4, the expansion valve 5, and the evaporator 6. After cooling the indoor air by heat exchange with the indoor air while passing through the accumulator (7) it is re-recovered back to the compressor (1).

Similarly, when the indoor cooling load is larger than the compression capacity of the first compressor and smaller than the compression capacity of the second compressor, only the second compressor 2 is independently operated in the same cycle as above, and the indoor cooling load is In the case where larger than the compression capacity of the two compressors is required, the two compressors (1, 2) are operated together.

However, in the case where a high-pressure shell compressor is used in such an air conditioner, as shown in FIG. 2, when only one compressor is operated due to a change in indoor cooling load while the two compressors are operated together, The normally operated compressor shown in the drawing compresses and discharges the refrigerant at a high pressure.

On the contrary, in the compressor in which the operation indicated by the dotted line is stopped, the discharged refrigerant is initially formed at a high pressure, but at a certain point, the refrigerant discharge pressure suddenly decreases and is formed in parallel with the suction pressure.

That is, when only one compressor of the two compressors is operated, only the check valve connected to the running compressor is operated, so that the back flow of the high pressure refrigerant of the compressor being operated is blocked by the check valve, but the refrigerant back flow of the discharge part of the stopped compressor is It is not blocked.

As a result, the discharge refrigerant pressure of the stopped compressor is rapidly decreased to be formed substantially in parallel with the refrigerant pressure of the suction unit, and when the compressor stopped again, the refrigerant pressure of the discharge unit rapidly rises.

However, in the stationary compressor, the time required for reaching the pressure equilibrium between the inlet pressure and the outlet pressure is very long, from 8 minutes to 23 minutes, and appears different depending on the compressor capacity and the system operating conditions.

In addition, since the stationary compressor cannot be operated until the pressure equilibrium is reached, it is impossible to immediately operate a compressor having a compression capacity suitable for fluctuations in the indoor load and thus cannot provide the cooling capacity of the required indoor load.

For example, in order to operate the first compressor having a small compression capacity while operating only the second compressor having a large compression capacity but stopped according to the change in the indoor load, the pressure balance point, that is, the pressure of the discharge part and the suction part of the compressor This equilibrium loss occurs at least 8 minutes up to 23 minutes until the air conditioner capacity of the air conditioner deteriorates.

In addition, since the time to reach the pressure balance varies according to the system operating conditions and the compressor capacity, sufficient safety time is taken into account in the actual system design. As a result, the compressor continues to stop even though the pressure balance is achieved under certain conditions. In order to solve the above problems, power consumption is increased by stopping and restarting all compressors.

In addition, when the two compressors are restarted after the pressure is balanced while the compressor is stopped in order to immediately respond to the change in the indoor load, problems caused by the system efficiency decrease due to the intermittent operation of the existing one compressor system. This same occurrence occurs and the effect of using two compressors is not greatly obtained.

In order to solve the above problems, an object of the present invention is to provide an air conditioner capable of shortening the pressure equalization time of the suction and discharge parts of a stationary compressor. By using a car, it is possible to shorten the pressure equilibrium time.

1 is a schematic diagram illustrating a cooling cycle of a conventional air conditioner in which two compressors are installed.

Figure 2 is a graph showing the pressure of the refrigerant sensed in the two compressor discharge and the suction

3 is a schematic configuration diagram showing a cooling cycle of an air conditioner according to the present invention in which two compressors are installed.

4 is a schematic structural diagram of a pressure balance valve according to the present invention;

5 is a structural diagram showing the operation of the pressure balance valve according to the present invention when the first compressor having a relatively small compression capacity is stopped.

6 is a structural diagram showing an operation state of the pressure balance valve according to the present invention when the second compressor having a relatively large compression capacity is stopped.

<Description of Signs of Main Parts of Drawing>

1: first compressor 2: 2nd compressor

3: oil separator 4: condenser

5: expansion valve 6: evaporator

7, 8: accumulator 9, 10: oil recovery pipe

To this end, the present invention provides two compressors having different compression capacities, check valves for blocking refrigerant flow into the injector outlets, an oil separator for recovering oil discharged from the compressor back to the compressor, and isothermal refrigerant. A condenser and evaporator for condensation and isothermal evaporation, an accumulator for allowing only refrigerant in the gas phase to flow into the inlet of each compressor, first and second discharge pipes connecting the respective compressors and the check valves, and the check valves, respectively. An air conditioner including a high pressure pipe connecting the oil separator and a suction pipe connecting the evaporator and the accumulator; Pressure equalizing means connected directly to the first and second discharge pipes and the suction pipe to directly communicate the suction and discharge parts of the stopped compressor in a single operation so as to shorten the pressure equalization time of the suction and discharge parts of the stopped compressor among the compressors. In this case, the pressure equalizing means is further connected to the high pressure pipe, and the suction part and the discharge part of the compressor stopped by the pressure difference between the first and second discharge pipes and the high pressure pipe. It is preferable that the pressure balance valve is used to directly open the unit or to operate the compressor in operation normally.

According to the present invention, an air conditioner installed with two compressors is described in detail as follows in accordance with the accompanying drawings.

3 is a schematic configuration diagram showing a cooling cycle of an air conditioner according to the present invention in which two compressors are installed, and FIG. 4 is a schematic diagram showing an operation process appearing in a pressure balance valve when two compressors are operated simultaneously. It is a structural diagram.

5 is a structural diagram showing the operation of the pressure balancing valve according to the present invention when the first compressor having a relatively small compression capacity is stopped. FIG. 6 is a diagram showing the operation of the second compressor having a relatively large compression capacity when the compressor is stopped. A structural diagram showing an operating state of a pressure balance valve according to the present invention.

As shown in FIG. 3, the air conditioner according to the present invention has a compressor having different capacities for compressing a refrigerant, and a check valve connected to the discharge port of each compressor so that the refrigerant compressed in the compressor is not flowed back. (11, 12) and an oil separator (3) for separating the oil adsorbed by the refrigerant and flowing out from the compressor.

In addition, a condenser 4 for isothermally condensing the high pressure refrigerant passing through the oil separator 3 by heat exchange with outdoor air, an expansion valve 5 for thermally expanding the condensed refrigerant, and a refrigerant by heat exchange with indoor air An evaporator (6) for evaporating the gas, an accumulator (7,8) for allowing only vapor phase refrigerant from the evaporated refrigerant to be introduced into the compressor, and an oil recovery pipe arranged to recover oil separated from the oil separator to the inlet of the accumulator. It consists of (9,10).

At this time, the pressure equalizing means 13 for controlling the flow path is connected to the air conditioner so as to be connected to the discharge port and the suction port of each compressor so that the high pressure refrigerant at the discharge port side of the stopped compressor flows to the suction port side to balance the refrigerant pressure.

Accordingly, the compressors 1 and 2 and the check valves 11 and 12 are connected to the first and second discharge pipes 41 and 42, and the check valves 11 and 12 and the oil separation pipe 3 are respectively connected. ) Is communicated with the first and second high pressure pipes (43, 44), the oil separator (3) and the condenser (4), expansion valve (5) and evaporator (6) are connected by connecting pipes, respectively, the evaporator (6) and each accumulator (7, 8) are in communication with the first and second suction pipes (45, 46).

At this time, the pressure balancing means 13 is connected to the first and second discharge pipes 41 and 42 by check valve voltage force pipes 31 and 32 so that the pressure difference between the front and rear of the check valve can be used, The first and second suction pipes connected to the first and second high pressure pipes connecting the check valve and the oil separator by the check valve after pressure pipe 33 and connecting the evaporator and the accumulator through the low pressure pipe 36 ( 45, 46, it is preferable that the pressure balance valve to directly communicate the suction and discharge of the stationary compressor or to operate the compressor in normal operation.

As shown in FIG. 4, the pressure balancing valve 13 has a separation plate 39 positioned at the center of the cylinder, and thus the first pressure balancing space 130 and the second pressure balancing space symmetrically with respect to the separation plate. 131 is formed.

In the pressure balancing spaces 130 and 131, pistons 37 and 38 are axially moved in the cylinder according to the pressure difference between the front and rear ends of the check valves 11 and 12.

In addition, the upper side of each pressure balance space (130,131) is connected so that the high pressure pipe (33) connecting the check valves (11, 12) and the oil separator (3) is branched into each pressure balance space, and each compressor (1) 2 and the first and second check valve voltage force pipes 31 and 32 connected to the discharge pipes 41 and 42 connecting the check valves 11 and 12, and the evaporator and the accumulator connected to the lower side. The low pressure pipe 36 connected to the suction pipes 45 and 46 is branched and communicated with each other.

At this time, the first and second check valve voltage force pipes 31 and 32 are branched and communicated with the side and the bottom of the pressure balance spaces 130 and 131 formed on both sides of the separation plate 39, respectively, and the lower portion of the pressure balance space. Grooves are formed in the lower surface of the piston so that a part of the check valve voltage force pipes 31 and 32 branched to the low pressure pipe 36 connected to the suction pipe communicates with each other.

Accordingly, a bypass space is formed in which the check valve voltage force tube communicates with the low pressure tube along a groove formed in the lower surface of the piston, and the pressure balance spaces 130 and 131 formed in the pressure balancer are equally symmetrically. Shape.

That is, the grooves are formed in the pistons 37 and 38 so that the bypass space is formed in the pressure equalizing space on the stationary compressor side, and the bypass space is not formed in the pressure equalizing space on the compressor side in operation ( 34, 35) is variable in size depending on the installation position between the check valve and the low pressure pipe.

When the air conditioner having such a configuration operates two compressors 1 and 2 together according to the indoor cooling load, the refrigerant compressed in each compressor passes through the discharge pipes 41 and 42 and the oil is separated from the oil separator 3. After this separation, the cycle of returning back to the compressor through the accumulators 7, 8 through the condenser 4, the expansion device 5 and the evaporator 6 is repeated.

At this time, the pressure balance valve 13 is maintained in a pressure state as shown in FIG.

The high pressure refrigerant is supplied through the first check valve voltage force tube 31 and the second check valve voltage force tube 32 connected to the discharge pipes 41 and 42 through which the refrigerant formed at high pressure in each of the compressors 1 and 2 flows. It is introduced into one end of the piston in the pressure balance space (130,131).

In addition, a portion of the refrigerant flowing into the oil separator 3 from the check valves 11 and 12 along each of the high pressure pipes 43 and 44 is introduced into one side of the pressure balance space through the pressure valve 33 after the check valve, respectively. do.

In addition, a low pressure refrigerant flows into the other side of the pistons 37 and 38 through the low pressure pipe 36 branched from the first suction pipe 45 and the second suction pipe 46 which communicate the evaporator and the accumulator.

Accordingly, in each of the pistons 37 and 38 in the pressure equalizing space, the pressure of the refrigerant introduced through the check valve voltage force tubes 31 and 32 is passed through the check valve post pressure tube 33 and the low pressure tube 36. Since the pressure is higher than the refrigerant flowing in, each of the pistons 37 and 38 is pushed toward the separating plate 39 and connected to the separating plate.

Therefore, since the position of the grooves 34 and 35 formed in the piston is changed so that a bypass space for communicating the check valve voltage tube and the low pressure tube is not formed, the high-pressure refrigerant discharged from the compressor cannot flow out to the suction port side of the compressor. .

On the contrary, when the cooling load of the room is changed so that the first compressor 1 having a relatively small compression capacity is stopped and only the second compressor 2 having a large compression capacity is operated, the piston formed in the pressure equalizer The axial movement is as shown in FIG.

That is, in the second pressure balance space 131 in which the compressor operates, the high pressure refrigerant is supplied to the piston through the second check valve voltage force tube 32 in communication with the second discharge pipe 42 connected to the second compressor 2. (38) flows into one end, and on one side, medium pressure refrigerant flows through the check valve after pressure pipe (33), and low pressure refrigerant flows into the other side of the piston through the low pressure pipe, and the piston enters the separation plate by the pressure difference. It is connected.

However, since the compressor does not compress the refrigerant in the second pressure equalizing space 130 connected to the first compressor that is stopped, the pressure of the refrigerant flowing through the pressure pipe 33 after the check valve is before the first check valve. Since it is higher than the pressure pipe 31 and the low pressure pipe 36, the piston 37 in the first pressure balance space 130 is spaced apart from the separating plate 39.

Accordingly, a branch pipe of the low branch pipe 31 and the lower branch pipe 31 of the first check valve high voltage pipe communicate with each other through the groove 34 formed in the lower portion of the first piston to form a bypass space. Due to the pressure difference between the high pressure refrigerant formed in the discharge port of the compressor and the low pressure refrigerant formed in the suction port, the refrigerant flows from the high pressure part to the low pressure part, thereby achieving pressure balance.

Therefore, when the indoor cooling load is further reduced and only the first compressor is operated, the operation switching of the compressor is made in a short time.

In addition, when the operation of the second compressor 2 is stopped and only the first compressor 1 is operated, as shown in FIG. 6, the check valve post pressure tube 33 is provided through the first check valve voltage force tube 31. Since the refrigerant having a pressure higher than) is introduced into the first pressure balance space 130, the piston 37 of the first pressure balance space is connected to the separator plate 39 so that a bypass space is not formed and a high pressure refrigerant flows out. It doesn't work.

On the contrary, in the second pressure balance space 131 connected to the non-operating second compressor, refrigerant having a lower pressure than the refrigerant introduced through the check valve after pressure pipe 33 flows into the second check valve voltage force pipe 32. The piston 38 is spaced apart from the separator plate 39.

Accordingly, the lower branch pipe of the second check valve voltage force pipe 32 and the branch pipe of the low pressure pipe 36 communicate with each other through the groove 35 formed in the piston 38 to discharge the discharge pipe 42 of the second compressor. The refrigerant flows from the suction pipe 46 to the pressure balance of the refrigerant.

As described above, the present invention allows the pressure equalization of the compressor which is not operated by using the pressure equalization means to be made quickly, so that the operation of the compressor is changed immediately according to the indoor cooling load of the air conditioner. Since the compression efficiency is effectively controlled using a compressor, the energy consumption efficiency of intermittent operation can be increased.

In addition, since the pressure balance valve is operated using the pressure difference, there is no risk of malfunction and energy consumption because it operates mechanically without requiring any electrical input or operation of the controller.

Claims (7)

Two compressors with different compression capacities, a check valve to block the flow of refrigerant to the outlet of each compressor, an oil separator for returning the oil from the compressor back to the compressor, and a condenser for isothermal condensation and isothermal evaporation of the refrigerant. And an evaporator, an accumulator for allowing only the refrigerant in the gas phase to flow into the inlet of each compressor, first and second discharge pipes respectively connecting the compressors and the check valves, and connecting the check valves and the oil separators. An air conditioner including a high pressure pipe and a suction pipe connecting the evaporator and the accumulators; Pressure equalizing means connected directly to the first and second discharge pipes and the suction pipe to directly communicate the suction and discharge parts of the stopped compressor in a single operation so as to shorten the pressure equalization time of the suction and discharge parts of the stopped compressor among the compressors. Air conditioner characterized in that it is made. delete delete delete delete The method of claim 1, The pressure balancing means; It is further connected to the high pressure pipe, it is characterized in that the pressure balance valve for directly communicating the suction and discharge of the compressor stopped by the pressure difference between the first and second discharge pipe and the high pressure pipe or normal operation of the compressor in operation. Air conditioner. The method of claim 6, The pressure balance valve is; Cylinders, A separation plate installed at the inner center end of the cylinder to partition an inner space into a first pressure balance space and a second pressure balance space; Pistons are provided in the first and second pressure balance space, respectively, The first and second discharge pipes are connected to both ends of the cylinder and branched to the separation plate and connected to lower ends of both sides of the cylinder. The high pressure pipe is branched to the separator plate and connected to both upper ends of the cylinder, The suction pipe is branched to the separator plate and connected to both lower ends of the cylinder, And a groove is formed in the lower end of the piston to connect the discharge pipe and the suction pipe of the stationary compressor side of the compressor.