JP2014020612A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner preventing the lowering of concentration of refrigerating machine oil by a refrigerant flooding state in a compressor.SOLUTION: An air conditioner is provided with an inside low pressure type compressor; a receiver capable of collecting refrigerating machine oil; and oil concentration detecting means for detecting the concentration of the refrigerating machine oil in the compressor. During the operation of the compressor, if a detection value detected by the oil concentration detecting means becomes a set value or more, a part of the refrigerating machine oil in the compressor is collected in the receiver by oil level difference between the compressor and the receiver. While the operation of the compressor is stopped, the receiver is insulated from a refrigerating cycle. When the compressor is started, if the detection value detected by the oil concentration detecting means is the set value or less, the refrigerating machine oil of high concentration collected in the receiver is supplied to the compressor by differential pressure between the compressor and the receiver.

Description

  The present invention relates to an air conditioner equipped with a function of supplying refrigerating machine oil to a compressor when the compressor is started, and preventing a decrease in oil concentration due to a stagnation state when the compressor is started.

  Conventionally, a compressor in an air conditioner is filled with a refrigerating machine oil for lubrication in a case. Generally, refrigeration oil that is easy to dissolve refrigerant is used. Therefore, when the compressor is shut down for a long time at a low outside temperature, the refrigerant in the refrigeration cycle returns to the compressor in which the refrigeration oil is stored, and then the refrigerant liquefies in the compressor and dissolves in the refrigeration oil in the compressor. It becomes a sleep state. When the compressor is started in this state, the low-concentration and low-viscosity refrigeration oil in which the refrigerant is dissolved is supplied to the sliding portion in the compressor, which causes a problem of poor lubrication and seizure. In addition, since oil forming occurs due to the stagnation state and the refrigeration oil is taken out of the compressor, the refrigeration oil level in the compressor is lowered, and the refrigeration oil is normally applied to sliding parts such as the compression mechanism in the compressor. The problem of not being supplied arises.

  There is an oil separator that separates the gas refrigerant discharged from the compressor into the discharge side pipe and the refrigerating machine oil and returns only the refrigerating machine oil to the suction side pipe (for example, JP-A-6-2962). Although this can prevent the oil level of the refrigerating machine oil from being lowered, the refrigerating machine oil returned immediately after the start-up of the compressor is diluted with liquid refrigerant and has a low viscosity, and the oil separator is in operation of the compressor. There is no refrigerating machine oil to return at startup. Therefore, poor lubrication cannot be prevented.

  As a method for preventing the refrigerant from stagnating in the refrigerating machine oil, there has been proposed a method in which a compressor that has been stopped is heated by a heater. (For example, JP-A-11-108473)

  However, in this method, since the compressor is heated using a heater, there is a problem that power consumption is increased. Also, it cannot be used when the power is turned off.

  On the other hand, as a method for preventing a decrease in the viscosity of the refrigeration oil, a method is proposed in which the concentration of the refrigeration oil is detected and the amount of refrigerant flowing into the compressor is adjusted by a decompression device when the concentration falls below a predetermined value. (For example, JP-A-5-5562)

  However, this method functions only after a predetermined time has elapsed since the start of operation of the compressor, and therefore does not function when the compressor is started.

JP-A-6-2962 JP 11-108473 A JP-A-5-5562

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide an air conditioner that prevents a decrease in the viscosity of the refrigerating machine oil due to a stagnation state when the compressor is started without using electric power. is there.

  In order to solve the above problems, an air conditioner according to claim 1 is an air conditioner having a refrigeration cycle in which an internal low-pressure compressor, a condenser, an expansion means, and an evaporator are sequentially connected by a refrigerant pipe. In the apparatus, a bottom face is provided side by side with the same height as the bottom face of the compressor, and a receiver capable of storing refrigerating machine oil is connected to the receiver and a discharge side pipe of the compressor to connect the receiver to a high pressure. A pressure pipe for supplying a refrigerant, a pressure balance pipe for connecting the receiver and a position where the refrigerating machine oil is not immersed when the compressor is stopped to equalize the receiver and the compressor, and a bottom surface of the receiver An oil moving pipe that connects the vicinity and the vicinity of the oil supply port of the compressor to circulate refrigeration oil, and a first on-off valve and a second on-off valve provided in the pressurizing pipe, the pressure balance pipe, and the oil moving pipe, respectively. valve A third on-off valve; control means; and oil concentration detection means included in the control means for detecting the concentration of the refrigerating machine oil in the compressor. The oil concentration detection means during operation of the compressor When the detected value detected by the above is equal to or greater than a preset set value A, the compressor and the receiver are equalized by opening the second on-off valve and allowing the pressure balance pipe to circulate, A part of the refrigerating machine oil in the compressor is accumulated in the receiver due to a difference in oil level between the compressor and the receiver by opening a third on-off valve so as to be able to flow in the oil moving pipe, and the compressor During the operation stop, the first on-off valve, the second on-off valve, and the third on-off valve are closed.

  The air conditioner according to claim 2 has the configuration according to claim 1, and the detected value detected by the oil concentration detecting means when the compressor is started is equal to or less than a preset set value B. Then, by opening the third on-off valve and communicating the oil moving pipe, the high-concentration refrigerating machine oil stored in the receiver is supplied to the compressor by the differential pressure between the pressure in the compressor and the pressure in the receiver. After the pressure in the compressor and the pressure in the receiver are equalized, if the detection value detected by the oil concentration detection means does not exceed the set value B, the first on-off valve is opened and the pressure tube The receiver is pressurized by allowing the refrigerant to flow, and the high-concentration refrigerating machine oil stored in the receiver is supplied to the compressor by a differential pressure between the pressure of the compressor and the pressure in the receiver. Be

  The air conditioner according to claim 3 has the configuration according to claim 1, and when the detected value of the oil concentration detecting means becomes equal to or less than a preset set value B when the compressor is started, 1 Open the on-off valve to pressurize the receiver by allowing it to flow through the pressurization pipe, and open the third on-off valve to enable the flow through the oil transfer pipe to store the high-concentration refrigerating machine oil stored in the receiver. The pressure is supplied to the compressor by a pressure difference between the pressure in the compressor and the pressure in the receiver.

  According to a fourth aspect of the present invention, in the air conditioner having the configuration of the third aspect, the pressurizing pipe is connected to a lower portion of a trap provided in the discharge side pipe.

  An air conditioner according to a fifth aspect of the present invention has the configuration of the first to third aspects, and is characterized in that a pressure reducing means is provided in the oil moving pipe.

  In the air conditioner of the present invention configured as described above, high-concentration refrigerating machine oil is accumulated in the receiver during operation of the compressor, and the receiver is shut off from the refrigerating cycle while the compressor is stopped. Therefore, since the refrigerant in the refrigeration cycle does not flow into the receiver, the refrigerating machine oil in the receiver maintains a high concentration even when the power is shut off, and does not cause a decrease in viscosity.

  Further, since the high-concentration refrigerating machine oil is directly supplied to the compressor when the compressor is started up, the refrigerating machine oil is smoothly supplied to the compressor, and no lubrication failure occurs. Further, even if the refrigerating machine oil is taken out of the compressor by oil forming, the refrigerating machine oil is supplied from the receiver, so there is no fear of oil level drop.

Schematic which shows the whole structure of the air conditioning apparatus which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the relationship between the compressor and receiver of the air conditioning apparatus which concern on the 1st Embodiment of this invention. The flowchart which shows the operation control operation | movement of the compressor and indoor fan of the air conditioning apparatus which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the relationship between the compressor and receiver of the air conditioning apparatus which concern on the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Overall configuration]
FIG. 1 is a schematic diagram illustrating an overall configuration of an air-conditioning apparatus 1 as an example of a refrigeration cycle according to the first embodiment. In the refrigerant cycle of the air conditioner 1 of the present embodiment, the compressor 10, the condenser 20, the expansion means 40, and the evaporator 50 are sequentially connected by refrigerant piping. Moreover, the discharge side piping 81 which connects the compressor 10 and the condenser 20, and the compressor 10 are each connected to the receiver 70 via the piping mentioned later.

  In FIG. 1, the high-temperature and high-pressure gas refrigerant compressed by the compressor 10 flows into the condenser 20 via the discharge side pipe 81 and is condensed by exchanging heat with the outside air in the condenser 20. Thereafter, it becomes a high-pressure liquid refrigerant and flows into the expansion means 40 via the refrigerant pipe 83. When the high-pressure liquid refrigerant that has flowed out of the condenser 20 passes through the expansion means 40, the pressure is reduced, the liquid refrigerant expands, and becomes a low-temperature and low-pressure liquid refrigerant that flows into the evaporator 50 through the refrigerant pipe 84. When the low-temperature and low-pressure liquid refrigerant that has flowed out of the expansion means 40 flows into the evaporator 50, the refrigerant evaporates by exchanging heat with the outside air, and becomes a low-pressure gas refrigerant. Thereafter, the air is sucked into the compressor 10 through the suction side pipe 82. The refrigeration cycle main circuit of the present embodiment is configured as described above.

  This refrigeration cycle is an irreversible cycle in which the refrigerant flow direction is constant, but may be a reversible cycle in which the refrigerant flow direction can be changed.

  Next, the relationship among the compressor 10, the receiver 70, the discharge side pipe 81, and the suction side pipe 82 will be described with reference to FIG.

[Compressor]
FIG. 2 is a cross-sectional view showing the relationship among the compressor 10, the receiver 70, the discharge side pipe 81, and the suction side pipe 82 according to the first embodiment. The compressor 10 is a variable capacity compressor 10 driven by a motor (for example, a three-phase brushless motor) whose rotational speed is controlled by the control means 60. In this embodiment, an internal low-pressure scroll compressor will be described as an example. However, the present invention is not limited to this as long as it is an internal low-pressure type, and may be another type of compressor such as a rotary compressor. The compressor 10 includes a cylindrical sealed container 11 (shell) placed vertically in an outdoor unit casing (not shown). The sealed container 11 includes a cylindrical body portion 11a, an upper lid 11b that is integrally covered with the upper end side of the body portion 11a, and a bottom lid 11c that closes the bottom portion of the body portion 11a. A steel plate is processed into a cylindrical shape, and the top lid 11b and the bottom lid 11c are made of casting. In the sealed container 11, a refrigerant compression mechanism portion 12 and an electric motor 13 that drives the compression mechanism portion 12 are housed. However, in the case of a scroll compressor, the compression mechanism portion 12 is disposed at the upper portion, and the electric motor 13. Is disposed below the compression mechanism 12.

  The compression mechanism unit 12 includes a fixed scroll (not shown) and a turning scroll that performs a turning motion by the electric motor 13, and a refrigerant suction port 14 formed in the fixed scroll is opened in the sealed container 11.

  Although not shown, the fixed scroll is formed with a refrigerant discharge port that discharges the refrigerant compressed by the orbiting scroll. The refrigerant discharge port is connected to a discharge side pipe 81, and the discharge side pipe 81 is connected to the sealed container 11. Is connected to the condenser 20 through the upper lid 11b.

  Normally, an inner rotor type electric motor in which a rotor 13b (rotor) is disposed inside a stator core 13a (stator) is used as the electric motor 13. The stator core 13a is fixed to the inner peripheral surface of the body portion 11a by shrink fitting, for example. The rotor 13b has an output shaft 13c connected to the orbiting scroll, and is rotatably held in the stator core 13a by a bearing member (not shown) via the output shaft 13c.

  A predetermined amount of refrigerating machine oil 15 for lubricating a sliding portion in the compressor 10 such as the bearing member is sealed in the sealed container 11. The refrigerating machine oil 15 is stored on the bottom lid 11c side, but the output shaft 13c has, for example, an oil suction hole that communicates with a positive displacement pump (not shown), and an oil supply port 13d is provided at the lower end. ing. The refrigerating machine oil 15 is sucked up to the upper side of the electric motor 13 with the rotation of the rotor 13b by the positive displacement pump described above, and after lubricating the sliding portion, for example, is formed between the stator core 13a and the trunk portion 11a. It returns to the bottom lid 11c side through a gap (not shown).

  The low-pressure refrigerant in the suction side pipe 82 flows into the sealed container 11 and is sucked into the compression mechanism portion 12 through the refrigerant suction port 14 provided in the fixed scroll and opened in the sealed container 11. After being compressed by the compression mechanism 12 to become a high-pressure refrigerant, it is discharged from the refrigerant discharge port to the discharge side pipe 81. Therefore, the closed container 11 is filled with a low-pressure refrigerant.

  Further, the first compressor opening 16 is provided at a position where the refrigerating machine oil 15 is not immersed when the operation of the compressor 10 is stopped in the trunk portion 11a constituting the sealed container 11, and the second compressor opening 17 is provided in the bottom lid 11c. , A pressure balance pipe 92 described later is connected to the first compressor opening 16, and an oil moving pipe 93 described later is connected to the second compressor opening 17.

[Receiver]
In FIG. 2, the receiver 70 is an airtight container provided so that the bottom surface is flush with the bottom surface of the compressor 10. The receiver 70 has a first upper surface opening 71 and a second upper surface opening 72 on the upper surface, and a bottom surface opening 73 near the bottom surface. The first upper surface opening 71 is connected to the discharge side pipe 81 via a pressure pipe 91, and the second upper surface opening 72 is connected to the first compressor opening 16 via a pressure balance pipe 92. The bottom opening 73 passes through the second compressor opening 17 via the oil moving pipe 93 and is connected to the vicinity of the oil supply port 13 d in the compressor 10. The pressurizing pipe 91, the pressure balance pipe 92, and the oil moving pipe 93 are provided with the first on-off valve 101, the second on-off valve 102, and the third on-off valve 103, which are controlled to open and close by the control means 60, respectively. Further, the oil moving pipe 93 is provided with a pressure reducing means 110.

[Pressure reduction means]
The decompression means 110 is connected to the oil moving pipe 93. A capillary tube or the like is used, and decompression and flow rate control are performed when the refrigerating machine oil 15 passes through the oil moving pipe 93.

[Oil concentration detection means]
Next, the oil concentration detection means 120 will be described. The concentration of the refrigerating machine oil 15 is uniquely determined by the pressure of the portion where the refrigerating machine oil 15 exists in the compressor 10 and the temperature thereof. Therefore, the oil concentration detection means 120 of the present embodiment is disposed outside the compressor 10 at a position corresponding to the refrigerating machine oil 15 storage unit, and detects the temperature of the refrigerating machine oil 15 via the body 11a of the sealed container 11. A temperature sensor 121 that is provided, a pressure sensor 122 that is provided in the suction side pipe 82 and that detects the evaporation pressure of the refrigerant sucked into the compressor 10, and is included in the control means 60 and is detected by the temperature sensor 121 and the pressure sensor 122. It comprises an oil concentration estimation unit 123 that estimates the oil concentration in the compressor 10 from the value. Based on the value obtained here, the first on-off valve 101, the second on-off valve 102, and the third on-off valve 103 are controlled.

  The temperature sensor 121 is externally attached to the body 11a at a position facing the refrigerating machine oil 15 reservoir outside the compressor 10. Since the trunk portion 11a is made of a steel plate having good thermal conductivity, the temperature of the refrigerating machine oil 15 in the sealed container 11 can be detected almost accurately even if it is indirect.

  The pressure sensor 122 is connected to the suction side pipe 82 and detects the evaporation pressure of the refrigerant sucked into the compressor 10.

  The detection signals detected by the temperature sensor 121 and the pressure sensor 122 are given to the oil concentration estimation unit 123 of the control means 60 via an A / D converter (not shown).

  If the temperature sensor 121 and the pressure sensor 122 are used to determine the refrigerating machine oil temperature and the suction pressure, the pressure saturation temperature can be calculated, and the difference between it and the actual temperature (refrigerating machine oil temperature) represents the solubility of the liquid-phase refrigerant in the refrigerating machine oil 15. Therefore, the concentration of the refrigerating machine oil 15 can be estimated from the refrigerating machine oil temperature and the suction pressure. The oil concentration estimation unit 123 converts the evaporation saturation pressure Pc to the evaporation saturation temperature Tc, where Tcomp is the temperature of the refrigerator oil 15 and Pc is the evaporation saturation pressure of the refrigerant output from the pressure sensor 122, and then the refrigerator oil temperature Tcomp. And a temperature difference ΔT (= Tcomp−Tc) between the evaporation saturation temperature Tc and the evaporation saturation temperature Tc. The concentration of the refrigerating machine oil 15 is estimated as this temperature difference ΔT. (Hereinafter referred to as oil concentration estimated value ΔT.)

[Control means]
In FIG. 1, the control means 60 mainly controls the rotation speed of the compressor 10 and the indoor fan 30, and further includes an oil concentration estimation unit 123 described later, and includes a first on-off valve 101, a second on-off valve 102, 3 Open / close control of the open / close valve 103 is performed.

  An indoor fan 30 driven by a motor whose rotational speed is controlled by the control means 60 is provided in the vicinity of the condenser 20. The indoor fan 30 promotes heat exchange between the refrigerant flowing in the condenser 20 and the outside air by generating an air flow.

  By the way, when the operation of the compressor 10 is stopped, the refrigerating machine oil 15 is diluted by dissolving the refrigerant in the sealed container 11. In particular, when the compressor 10 is stopped for a long time at a low outside air temperature (for example, about −20 ° C.), the refrigerant in the refrigeration cycle of the air conditioner 1 concentrates on the compressor 10 in which a large amount of refrigeration oil 15 is stored. Thereafter, the refrigerant is liquefied in the compressor 10 and is in a stagnation state where it is dissolved in the refrigerating machine oil 15 in the compressor 10. When the compressor 10 is started in this state, the low-viscosity refrigerating machine oil 15 in which the refrigerant has stagnated is supplied to the sliding portion in the compressor 10, which causes a problem of poor lubrication and seizure. Further, oil forming caused by the stagnation state occurs, and the refrigerating machine oil 15 is taken out of the compressor 10, so that the lubricating oil surface in the compressor 10 is lowered, and the refrigerating machine oil 15 is normally slid in the compressor 10. There arises a problem that it is not supplied to the section.

  Therefore, it is important that the concentration of the refrigerating machine oil 15 in the compressor 10 is high when the compressor 10 is started. Below, the operation | movement which supplies high concentration oil at the time of starting of the compressor 10 of this invention is demonstrated using FIG.

[Oil recovery operation]
First, the opening / closing control of the first on-off valve 101, the second on-off valve 102, and the third on-off valve 103 by the control means 60 when the refrigerating machine oil 15 in the compressor 10 is recovered by the receiver 70 will be described with reference to FIG. To do.

  During the operation of the compressor 10, the oil concentration detection means 120 detects the estimated oil concentration value ΔT. The control means 60 determines whether the oil concentration estimated value ΔT is a preset value of Adeg. In the case above, it is estimated that the concentration of the refrigerating machine oil 15 staying on the bottom lid 11c side of the sealed container 11 is sufficiently high, and the second on-off valve 102 and the third on-off valve 103 are opened. By opening the second on-off valve 102, the receiver 70 and the compressor 10 communicate with each other through the pressure balance pipe 92, and the receiver 70 and the compressor 10 are equalized. Further, by opening the third on-off valve 103, the refrigerating machine oil 15 staying on the bottom lid 11c side of the sealed container 11 flows into the receiver 70 through the oil moving pipe 93 due to the difference in the oil level. After that, when the predetermined time (the time required for the oil level of the refrigerating machine oil 15 in the receiver 70 and the oil level of the refrigerating machine oil 15 in the compressor 10 to reach the same level) has passed, the control means 60 passes the second on-off valve 102. Then, the third on-off valve 103 is closed. With the above operation, the high-concentration refrigerating machine oil 15 in the compressor 10 is collected in the receiver 70.

  After the refrigerating machine oil 15 is collected, the receiver 70 is shut off from the refrigerating cycle while the low-pressure refrigerant is contained together with the refrigerating machine oil 15. When the compressor 10 stops, there is no differential pressure in the refrigeration cycle, and the pressure becomes equal throughout the refrigeration cycle. Then, the shut-off receiver 70 has a lower pressure than the compressor 10 that has equalized pressure over the entire cycle. Therefore, if the on-off valve 103 is opened when supplying the refrigerating machine oil 15 from the receiver 70 to the compressor 10, the refrigerating machine oil 15 flows backward from the compressor 10 into the low-pressure receiver 70. In order to prevent this, the second on-off valve 102 is opened after the operation is stopped.

  Thereafter, when the pressure becomes equal, the second on-off valve 102 is closed, and the receiver 70 is not connected to the refrigeration cycle while the operation of the compressor 10 is stopped. As a result, the refrigerant does not flow into the receiver 70 when the operation of the compressor 10 is stopped. Therefore, the refrigerant is prevented from sleeping in the refrigerating machine oil 15 in the receiver 70, and the refrigerating machine oil 15 is kept at a high concentration until the compressor 10 is started. Can be kept in.

  The refrigerating machine oil 15 is collected until the oil level of the refrigerating machine oil 15 in the receiver 70 and the oil level of the refrigerating machine oil 15 in the compressor 10 are at the same level. Since it must remain in the compressor 10, it is necessary to adjust the size of the receiver 70 in advance.

[Oil supply operation]
Next, the opening / closing control of the first on-off valve 101, the second on-off valve 102, and the third on-off valve 103 by the control means 60 when the refrigerating machine oil 15 collected in the receiver 70 is supplied to the compressor 10 will be described.

  When the compressor 10 is started, the oil concentration detection means 120 detects the oil concentration estimated value ΔT. If the relationship between ΔT and the setting value B that supplies the refrigerating machine oil 15 from the receiver 70 to the compressor 10 is less than this value, ΔT <B, the control means 60 may The third open / close valve 103 is opened by estimating that the refrigerating machine oil 15 staying on the 11c side has been diluted by the refrigerant and the concentration has decreased. When the compressor 10 is started, the inside of the compressor 10 gradually becomes a low pressure. At this time, the pressure in the receiver 70 is maintained when the second on-off valve 102 is opened after the operation is stopped and the pressure is equalized with the entire refrigeration cycle. Therefore, by opening the third on-off valve 103, the receiver 70 and the vicinity of the oil filler opening 13d in the compressor 10 are communicated by the oil moving pipe 93, and the pressure in the receiver 70 and the pressure in the compressor 10 are equalized. Try to become pressure. In this case, since the pressure in the receiver 70 becomes higher than the pressure in the compressor 10, the refrigeration oil 15 in the receiver 70 flows into the compressor 10. Thereafter, the estimated oil concentration value ΔT is detected by the oil concentration detecting means 120, and when ΔT> B, the third on-off valve 103 is closed. With the above operation, the high-concentration refrigerating machine oil 15 collected in the receiver 70 when the compressor 10 is started can be supplied to the vicinity of the oil supply port 13 d in the compressor 10.

  Further, since this supply operation uses a differential pressure generated at the time of start-up, when the pressure in the receiver 70 and the pressure in the compressor 10 are equalized, the refrigerating machine oil 15 between the receiver 70 and the compressor 10 is discharged. Although the movement is interrupted, the supply of the refrigerating machine oil 15 to the compressor 10 is resumed when a differential pressure occurs again, such as by increasing the rotational speed of the compressor 10.

  Further, when the pressure in the receiver 70 and the pressure in the compressor 10 become equal and the supply of the refrigerating machine oil 15 is interrupted, the oil concentration detection means 120 detects the estimated oil concentration value ΔT. When ΔT <B, the first on-off valve 101 is opened. By opening the first on-off valve 101, the discharge side pipe 81 and the receiver 70 communicate with each other through the pressurizing pipe 91. As a result, the high-pressure refrigerant discharged from the compressor 10 to the discharge side pipe 81 is supplied to the receiver 70 to pressurize the receiver 70. Then, since the pressure in the receiver 70 becomes higher than the pressure in the compressor 10, the refrigerating machine oil 15 flows into the compressor 10. Thereafter, the estimated oil concentration value ΔT is detected by the oil concentration detecting means 120. When ΔT> B, the first on-off valve 101 and the third on-off valve 103 are closed.

  With the above operation, when the compressor 10 is stopped, the high-concentration refrigerating machine oil 15 is stored in the receiver 70 that is cut off from the refrigerating cycle, so that the refrigerant in the refrigerating cycle pipe concentrates on the compressor 10. However, it does not lie in the refrigerating machine oil 15 in the receiver 70 and can maintain a high concentration even when the power is shut off. Further, since the high-concentration refrigerating machine oil 15 is directly supplied to the vicinity of the oil filler opening 13d in the compressor 10 when the compressor 10 is started, the refrigerating machine oil is smoothly supplied to the compressor 10 and lubrication is performed. Prevent defects. Further, even if the refrigerating machine oil 15 is taken out of the compressor 10 by oil forming, the refrigerating machine oil 15 is supplied from the receiver 70, so there is no fear of oil level drop.

  Next, the air conditioning apparatus 1 in 2nd Embodiment is demonstrated using FIG. 3 thru | or FIG. In the air conditioner 1 of the present embodiment, the refrigerant circuit includes a compressor 10, a condenser 20, an expansion means 40, and an evaporator 50 that are sequentially connected by a refrigerant pipe. The compressor 10 and the condenser Since the configuration in which the discharge side pipe 81 connecting to the compressor 20 and the compressor 10 are connected to the receiver 70 by pipes is the same as that of the first embodiment, detailed description thereof is omitted. This example is the air conditioner 1 having the control of improving the startup performance of the compressor 10 in the air conditioner 1 having the configuration of the first embodiment.

[Feedback control]
Conventionally, in order to prevent the oil level from being lowered due to the discharge of the refrigerating machine oil 15 from the compressor 10 when the compressor 10 is started, the rotational speed immediately after the compressor 10 is started is kept at a low value and gradually increased to the required rotational speed. Thus, the amount of the refrigerating machine oil 15 discharged from the compressor 10 to the refrigerating cycle is suppressed, and the time until the refrigerating machine oil 15 discharged to the outside of the compressor 10 is recovered into the compressor 10 is gained. . However, this is predetermined in consideration of the safety factor under severe conditions, and depending on the starting conditions, even if there is a margin in the actual oil level, the capacity may be suppressed more than necessary.

  The purpose of this embodiment is to solve the above-described problem, and the concentration of the refrigerating machine oil 15 in the compressor 10 is detected, and the rotational speed of the compressor 10 and the indoor fan 30 is controlled based on the detected value. is there. Hereinafter, the control of this embodiment will be described with reference to the flowchart of FIG.

[Compressor speed control]
FIG. 3 is a flowchart of the rotational speed control of the compressor 10 based on the oil concentration detection means 120 of the present embodiment. After starting the compressor 10 in ST1, an oil concentration estimation value ΔT is estimated by the oil concentration detection means 120 in ST2, and ΔT is set to an initial value ΔT0. If ΔT <B in ST3, the process proceeds to ST4, where it is determined whether the first on-off valve 101 and the third on-off valve 103 are closed. If they are closed, the process proceeds to ST5, where the first on-off valve 101 and the third on-off valve 103 are opened. The supply operation of the refrigerating machine oil 15 is started by controlling. Thereafter, in ST6, the rotation speed (RPMcomp) of the compressor 10 and the rotation speed (RPMfan) of the indoor fan 30 are held at the respective rotation speeds at that time. On the other hand, if ΔT ≧ B in ST3, the process proceeds to ST7, the rotation speed (RPMcomp) of the compressor 10 is compared with the requested rotation speed (RPMcomps), and if RPMcomp <RPMcomps, the process proceeds to ST8. The following rotation speed control of the compressor 10 is started.

  In the rotation speed control of the compressor 10, first, the oil concentration detection unit 120 estimates the oil concentration estimated value ΔT again in ST8, and compares ΔT at that time with the initial value ΔT0. When ΔT> ΔT0, the process proceeds to ST9, and the rotation speed (RPMcomp) of the compressor 10 is greatly increased. On the other hand, if ΔT ≦ ΔT0, the process proceeds to ST10, and if ΔT = ΔT0, the process proceeds to ST11, and the rotational speed (RPMcomp) of the compressor 10 is slightly increased. On the other hand, if ΔT <ΔT0, the process proceeds to ST12, where it is determined that the refrigerant has stagnated in the refrigerating machine oil 15, and the rotation speed (RPMcomp) of the compressor 10 is held at the rotation speed at that time. After controlling the rotation speed of the compressor 10, the process returns to ST2.

[Indoor fan speed control]
Next, in ST7, the rotation speed (RPMcomp) of the compressor 10 is compared with the requested rotation speed (RPMcomps). If RPMcomp ≧ RPMcomps, the process proceeds to ST13 to detect the temperature of the condenser 20 (not shown). When the indoor unit temperature (Ti) detected by the condenser temperature sensor exceeds the indoor unit temperature set value (Ts), the process proceeds to ST14, the indoor fan 30 is activated, and the process proceeds to ST15. If Ti ≦ Ts, the process returns to ST2. In ST15, when the rotational speed (RPMfan) of the indoor fan 30 is lower than the requested rotational speed (RPMfans), the process proceeds to ST16 and the following rotational speed control of the indoor fan 30 is started.

  In the rotation speed control of the indoor fan 30, first, in ST16, the oil concentration detection means 120 estimates the oil concentration estimated value ΔT, and the change amount is set to the set value (C) due to a rapid concentration change from the initial value ΔT0 to ΔT at that time. Judge whether it exceeds. For example, when the estimated oil concentration value ΔT is rapidly decreased, it can be determined that the refrigerant is being dissolved, and when the estimated oil concentration value ΔT is rapidly increased, the refrigerant is evaporated due to a pressure change. It can be determined that the oil level has dropped. When −C ≦ ΔT−ΔT0 ≦ C, the process proceeds to ST17, and the rotation speed (RPMfan) of the indoor fan 30 is increased small. On the other hand, if [Delta] T- [Delta] T0 <-C or C <[Delta] T- [Delta] T0 in ST16, the process proceeds to ST18, and the rotational speed (RPMfan) of the indoor fan 30 is held at the rotational speed at that time. After controlling the rotation speed of each indoor fan 30, the process returns to ST2.

Next, in ST15, the rotation speed (RPMfan) of the indoor fan 30 is compared with the requested rotation speed (RPMfans). If RPMfan ≧ RPMfans, the process proceeds to ST19.
It is determined whether the first on-off valve 101 and the third on-off valve 103 are open. When the opening control is performed by the supply operation of the refrigerating machine oil 15, the process proceeds to ST20, the first opening / closing valve 101 and the third opening / closing valve 103 are controlled to be closed, and then normal operation is performed. If the first on-off valve 101 and the third on-off valve 103 are closed in ST19, the operation is switched to the normal operation as it is.

  By controlling the rotational speed of the compressor 10 and the rotational speed of the indoor fan 30 as described above, the rotational speed of the compressor 10 can be increased faster than the conventional starting method of the compressor 10, so that the startup performance is improved. improves.

[Oil return]
When the rotational speed is increased by the rotational speed control of the compressor 10 described above, the amount of oil discharged from the compressor 10 increases. Then, there arises a problem that the supply amount at the time of starting the compressor 10 cannot be sufficiently secured with the oil amount of the refrigerating machine oil 15 stored in the receiver 70. Therefore, it is necessary to return the refrigerating machine oil 15 discharged from the compressor 10 to the receiver 70, and the configuration thereof will be described below.

  FIG. 4 is a cross-sectional view showing the relationship between the compressor 10 and the receiver 70 of the second embodiment. Similarly to the first embodiment, the receiver 70 is a sealed container provided so that the bottom surface is flush with the bottom surface of the compressor 10. The receiver 70 has a first upper surface opening 71 and a second upper surface opening 72 on the upper surface, and a bottom surface opening 73 near the bottom surface. A pressure tube 91 is connected to the first upper surface opening 71, and a pressure balance tube 92 is connected to the second upper surface opening 72. An oil moving pipe 93 is connected to the bottom opening 73. The pressurizing pipe 91, the pressure balance pipe 92, and the oil moving pipe 93 are provided with the first on-off valve 101, the second on-off valve 102, and the third on-off valve 103, which are controlled to open and close by the control means 60, respectively. Further, the oil moving pipe 93 is provided with a pressure reducing means 110. In this embodiment, a trap 130 is provided in the discharge side pipe 81, and the pressurizing pipe 91 is connected to a trap lower part 131 that serves as a liquid reservoir for the trap 130. As a result, the refrigerating machine oil 15 discharged together with the refrigerant from the compressor 10 is collected in the trap lower part 131 of the trap 130, and the accumulated refrigerating machine oil 15 is recovered by the receiver 70 through the pressurizing pipe 91. Even if the rotational speed is increased by controlling the rotational speed of the machine 10, the refrigerating machine oil 15 supplied at the time of startup can be sufficiently secured.

  Next, the collection | recovery operation | movement and supply operation | movement of the refrigerating machine oil 15 in the structure of a present Example are demonstrated below.

[Oil recovery operation]
The on-off control of the first on-off valve 101, the second on-off valve 102, and the third on-off valve 103 by the control means 60 when collecting the refrigerating machine oil 15 in the compressor 10 to the receiver 70 is the same as in the first embodiment. Therefore, it is omitted.

[Oil supply operation]
Next, opening / closing control of the electromagnetic first on-off valve 101, the second on-off valve 102, and the third on-off valve 103 by the control means 60 when supplying the refrigerating machine oil 15 collected to the receiver 70 to the compressor 10 will be described.

  When the compressor 10 is started, the oil concentration detection means 120 detects the oil concentration estimated value ΔT. If the relationship between ΔT and a preset value B at which refrigeration oil is supplied from the receiver to the compressor when ΔT <B is below this value, ΔT <B, the control means 60 controls the bottom lid 11c of the sealed container 11 It is presumed that the refrigerating machine oil 15 staying on the side is diluted with the refrigerant and the concentration is lowered, and the first on-off valve 101 and the third on-off valve 103 are opened. By opening the first on-off valve 101, the discharge side pipe 81 and the receiver 70 are communicated by the pressurizing pipe 91. As a result, the high-pressure refrigerant discharged from the compressor 10 to the discharge-side pipe 81 is supplied to the receiver 70 and pressurizes the receiver 70. By opening the third on-off valve 103, the receiver 70 and the compressor 10 are communicated with each other by the oil moving pipe 93, and the pressure in the receiver 70 and the pressure in the compressor 10 tend to be equalized. In this case, since the pressure in the receiver 70 becomes higher than the pressure in the compressor 10, the refrigerating machine oil 15 in the receiver 70 flows into the vicinity of the oil supply port 13 d in the compressor 10. Thereafter, the estimated oil concentration value ΔT is detected by the oil concentration detecting means 120, and when ΔT> B, the third on-off valve 103 is closed. With the above operation, the high-concentration refrigerating machine oil 15 collected in the receiver 70 is supplied to the compressor 10.

  With the above-described configuration, even if there is a margin in the actual oil level at the time of startup, the capacity can be increased more quickly than necessary, and the rotation speed of the compressor 10 can be increased faster than the conventional startup method. Will improve.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 10 Compressor 11 Sealed container 11a Body part 11b Top cover 11c Bottom cover 12 Compression mechanism part 13 Electric motor 13a Stator core 13b Rotor 13c Output shaft 13d Oil supply port 14 Refrigerant intake port 15 Refrigeration machine oil 16 First compressor opening part 17 2 compressor opening 20 condenser 30 indoor fan 40 expansion means 50 evaporator 60 control means 70 receiver 71 first upper surface opening 72 second upper surface opening 73 bottom surface opening 81 discharge side piping 82 suction side piping 83 refrigerant piping 84 Refrigerant piping 91 Pressurizing pipe 92 Pressure balance pipe 93 Oil moving pipe 101 First on-off valve 102 Second on-off valve 103 Third on-off valve 110 Pressure reducing means 120 Oil concentration detecting means 121 Temperature sensor 122 Pressure sensor 123 Oil concentration estimating section 130 Trap 131 Trap bottom

Claims (5)

In an air conditioner including a refrigeration cycle in which an internal low-pressure compressor, a condenser, an expansion means, and an evaporator are sequentially connected by a refrigerant pipe,
A receiver that is provided side by side with the same height as the bottom surface of the compressor, and that can store refrigerating machine oil;
A pressurized pipe for connecting the receiver and a discharge side pipe of the compressor and supplying a high-pressure refrigerant to the receiver;
A pressure balance pipe that equalizes the receiver and the compressor by connecting the receiver and a position where the refrigerating machine oil is not immersed when the compressor is stopped;
An oil moving pipe that connects the vicinity of the bottom surface of the receiver and the vicinity of the oil filler opening of the compressor and distributes refrigeration oil;
A first on-off valve, a second on-off valve, and a third on-off valve respectively provided on the pressurizing pipe, the pressure balance pipe, and the oil moving pipe;
Control means, and oil concentration detection means included in the control means for detecting the concentration of the refrigerating machine oil in the compressor,
During operation of the compressor, when the detected value detected by the oil concentration detecting means is equal to or higher than a preset set value A, the second on-off valve is opened to allow the inside of the pressure balance pipe to flow. By equalizing the compressor and the receiver, and further opening the third on-off valve so that the oil moving pipe can be circulated, a part of the refrigerating machine oil in the compressor is separated from the compressor and the receiver. Accumulated in the receiver due to oil level difference,
The air conditioner is characterized in that the first on-off valve, the second on-off valve, and the third on-off valve are closed while the compressor is stopped.   When the compressor is started, when the detected value detected by the oil concentration detecting means is equal to or less than a preset set value B, the third open / close valve is opened and the oil moving pipe is communicated to store in the receiver. A high concentration refrigeration oil is supplied to the compressor by a differential pressure between the pressure in the compressor and the pressure in the receiver, and after the pressure in the compressor and the pressure in the receiver are equalized, If the detection value detected by the oil concentration detection means does not exceed the set value B, the first on-off valve is opened to allow the pressurization pipe to flow, the receiver is pressurized, and the high concentration stored in the receiver is stored. The air conditioner according to claim 1, wherein the refrigerating machine oil is supplied to the compressor by a differential pressure between a pressure of the compressor and a pressure in the receiver.   When the compressor starts up, if the detection value of the oil concentration detection means is equal to or lower than a preset value B, the receiver is pressurized by opening the first on-off valve and allowing the inside of the pressure pipe to flow, By opening the third on-off valve and allowing it to flow through the oil moving pipe, high-concentration refrigerating machine oil stored in the receiver is supplied to the compressor by the differential pressure between the pressure in the compressor and the pressure in the receiver. The air conditioning apparatus according to claim 1, wherein:   The air conditioner according to claim 3, wherein the pressurizing pipe is connected to a lower portion of a trap provided in a discharge side pipe of the compressor. The air conditioner according to any one of claims 1 to 4, wherein a pressure reducing means is provided in the oil moving pipe.

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