JP2006084122A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of securing an oil diluting ratio, and capable of preventing reduction in an oil level, by using a compressor with an oil level detector, by constituting a refrigerating cycle incorporated with a separator with an oil tank for storing spare oil. <P>SOLUTION: This air conditioner is provided with the separator with the oil tank for storing the spare oil, and is provided with a first oil return pipe opening in an upper part than a spare oil surface and a second oil return pipe opening in a lower part than the spare oil surface. The pipe length becomes long, and a refrigerant is added and replenished, and in the refrigerating cycle unable to secure the oil diluting ratio, the oil diluting ratio of the refrigerating cycle is secured by supplying the oil from the second oil return pipe, and reliability of the refrigerating cycle can be improved by preventing reduction in the oil level by using the compressor with the oil level detector. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigeration cycle of an air conditioner in which a plurality of indoor units and a plurality of outdoor units are connected in parallel.

  In recent years, air conditioners have become more space-saving due to improvements in living standards and workability, and there has been an increasing demand for air conditioning in the entire building. As the demand for multi-chamber air conditioners, etc., increases, the design for stabilizing the refrigeration oil held by compressors has been made.

  In general, an air conditioner in which a plurality of indoor units and a plurality of outdoor units are connected in parallel is known. In this type of pipe, the length of the pipe to be connected is increased, and the refrigerant is additionally replenished to compensate for the shortage of the refrigerant amount. As a result, the amount of oil in the refrigeration cycle tends to be insufficient, and the ratio of the amount of oil (hereinafter referred to as “oil dilution rate”) decreases, thereby affecting the reliability of the compressor.

FIG. 5 is a system diagram showing a conventional air conditioner. The refrigeration cycle is formed by a refrigerant circulation cycle extending from a compressor, a condenser, a throttling device, an evaporator, an accumulator, and a compressor, and an oil reservoir is interposed between the compressor and the condenser. This is because the risk of seizing due to insufficient supply of lubricating oil to the compressor is avoided by returning the lubricating oil that has flowed into the discharge gas of the compressor to the compressor, and the oil is contained in the circulating refrigerant. It is mixed and prevents the freezing capacity from being lowered. This oil sump container is formed in a sealed container shape, and the discharge gas flows into the container from the inlet connected to the discharge side of the compressor, and the oil in the discharge gas is dropped and stored in the container. The refrigerant gas except for is circulated from the outlet connected to the suction side of the condenser. The oil stored inside the container is configured to return the oil to a suction pipe connected to the oil return pipe at a predetermined liquid level by installing a float in the container.
JP 11-117884 A

  In such an air conditioner, if a conventional oil sump container is used, the oil separated from the refrigerant can be returned to the compressor. However, the type of indoor unit to be connected may change or increase in number depending on the user's request. When a plurality of outdoor units are connected, the pipes to be connected become longer, and the refrigerant is additionally replenished to compensate for the shortage of the refrigerant amount. As a result, the amount of oil in the refrigeration cycle tends to be insufficient, and the oil dilution rate cannot be secured. For this reason, a compressor with a large amount of oil filling has to be developed and replaced.

  The present invention solves the conventional problems, and an oil sump container (hereinafter referred to as a separator with an oil tank) having a predetermined capacity and capable of storing spare oil is provided on the high pressure side, whereby a plurality of compressors are provided. Also in the air conditioner that is installed, the oil level in each compressor can be secured, and the reliability can be improved. In addition, since the separator with an oil tank has a predetermined capacity, the separator with an oil tank also serves as a buffer for increasing or decreasing the amount of oil remaining in the pipe. Furthermore, even in the case of a refrigeration cycle in which multiple outdoor units are connected in parallel, the oil tank separator can be used to distribute oil so that each outdoor unit does not run out of oil or excessive oil. Unaffected by refrigerant and oil characteristics. Furthermore, by using a compressor with an oil level detector, the oil dilution rate of the refrigeration cycle is secured, and even if the oil level decreases, the oil is more reliably reduced to a compressor with an oil level detector. The purpose is to use a separator with an oil tank that can be returned.

  In order to solve the conventional problems, an air conditioner of the present invention includes a storage chamber for storing spare oil in advance, a first oil return pipe opened above the spare oil surface, and a spare oil. By providing a separator with an oil tank having a second oil return pipe opened below the oil surface in a high-pressure gas circuit in which the refrigerant always becomes a gas phase, the refrigerant was discharged into the discharge gas of the compressor, which is a basic function. Lubricating oil can be separated and stored and returned to the compressor, and by using a compressor with an oil level detector, the oil dilution rate of the refrigeration cycle can be ensured and the oil level can be more reliably reduced. It becomes possible to return the oil to the compressor with the oil level detector whose oil level is lowered.

  The air conditioner of the present invention has a storage chamber for storing spare oil in advance, a first oil return pipe opened above the spare oil surface, and a first oil return pipe opened below the oil surface of the spare oil. By providing a separator with an oil tank having two oil return pipes in a high-pressure gas circuit in which the refrigerant always becomes a gas phase, the lubricating oil that has flowed into the discharge gas of the compressor, which is a basic functional component, is separated and stored, It can be returned to the compressor, and by using a compressor with an oil level detector, the oil level is more reliably lowered even if the oil level falls while ensuring the oil dilution rate of the refrigeration cycle It becomes possible to return to the compressor with the oil level detector.

  When the compressors with oil level detectors are connected in parallel, the oil accumulated in the first oil storage chamber is always returned to the specific compressor with oil level detector. Here, since the compressor with the oil level detector is connected in parallel, for example, the oil discharged from the compressor with the oil level detector does not return to the compressor with the oil level detector, May accumulate in compressor with surface detector. At this time, because there is a shortage of oil in a compressor with an oil level detector, the oil accumulated in the second oil storage chamber is sent to the compressor with an oil level detector that has run out of oil and the oil level has dropped. Therefore, it is possible to improve the reliability of the refrigeration cycle while ensuring the oil dilution rate in the refrigeration cycle.

  The present invention provides a refrigerant gas inlet connected to a discharge side of a compressor and a refrigerant gas outlet connected to a suction side of a condenser to separate the refrigerant mixed with oil discharged from the compressor into oil and refrigerant. A first oil return pipe that houses an oil separation mechanism, is introduced with oil separated by the oil separation mechanism, and has a storage chamber for storing spare oil, and is opened above the spare oil surface. When the oil level cannot be ensured in a refrigeration cycle in which a separator with an oil tank provided with a second oil return pipe opened below the spare oil surface is interposed between the compressor and the condenser The oil is supplied from the second oil return pipe, and the refrigeration cycle is constituted by the compressor with the oil level detector.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not limited by embodiment described below.

(Embodiment 1)
In FIG. 1, the outdoor unit B1a is connected to a plurality of indoor units A1 and A2 via a liquid pipe 41 and a gas pipe 51, and the accumulator 61 → the compressor 11 with an oil level detector → the condenser 21 → the throttling device 31 as a refrigerant. In a refrigeration cycle sequentially connected by piping, an oil tank separator 71 having a predetermined capacity is interposed between the compressor 11 with an oil level detector and the condenser 21. As described above, the oil separator 71 with an oil tank has a function of storing spare oil in advance and separating the oil contained in the refrigerant to always return the oil to the compressor 11 with an oil level detector. In addition, a function for returning the oil to the compressor 11 with the oil level detector in which the oil is insufficient and the oil level is lowered is added.

  The separator 71 with an oil tank is installed between the outlet of the compressor 11 with an oil level detector and the inlet of the condenser 21, and an oil separation mechanism is housed therein, where the refrigerant gas has flowed into the discharge gas. Separate and drop the oil. An oil storage chamber is provided in which dripped oil is introduced and spare oil is stored. The first oil return pipe 81 is provided above the spare oil surface, and the second oil is provided below the spare oil surface. A return pipe 82 is provided.

  Normally, when there is one indoor unit, the oil separated in the separator 71 with an oil tank is returned from the first oil return pipe 81 to the inlet pipe of the compressor 11 with an oil level detector. When a plurality of indoor units A1 and A2 are connected and the refrigerant is additionally replenished and there is a concern about a decrease in the oil dilution rate, the oil dilution rate is secured because the reserve oil is stored in advance. During operation, when the oil level of the compressor 11 with oil level detector decreases, the on-off valve 91 of the second oil return pipe 82 is opened according to information from the oil level detector 101 built in the compressor 11 with oil level detector. By returning the reserve oil to the compressor 11 with the oil level detector, the oil level in the compressor 11 with the oil level detector can be secured, and the reliability of the refrigeration cycle can be improved.

(Embodiment 2)
In FIG. 2, the outdoor unit side B2a is connected to a plurality of indoor units A1 and A2 via a liquid pipe 41 and a gas pipe 51, and an accumulator 61 → a plurality of compressors 11, 12 with oil level detectors → a condenser 21 → In a refrigeration cycle in which the expansion devices 31 are sequentially connected by refrigerant piping, an oil separator 71 with an oil tank is interposed between a plurality of compressors 11 and 12 with an oil level detector and the condenser 21.

  This separator 71 with an oil tank is installed between the junction from the outlet of the compressor 11 with the oil level detector and the outlet of the compressor 12 with the oil level detector and the inlet of the condenser 21, and the oil separation mechanism is housed therein. Here, the refrigerant gas separates and drops the oil that has flowed into the discharge gas. An oil storage chamber is provided in which the dropped oil is introduced and the spare oil is enclosed. The first oil return pipe 81 is provided above the spare oil surface, and the second oil is provided below the spare oil surface. Return pipes 82a and 82b are provided.

  Usually, when there is one indoor unit, the oil separated in the separator 71 with an oil tank is returned from the first oil return pipe 81 to the inlet pipes of a plurality of compressors 11 and 12 with oil level detectors. The When a plurality of indoor units A1 and A2 are connected and the refrigerant is additionally replenished and there is a concern about a decrease in the oil dilution rate, the oil dilution rate is secured because the reserve oil is stored in advance. When the oil level of the compressors 11 and 12 with oil level detector is lowered during operation, the second oil return pipe 82a is determined by information from the oil level detectors 101 and 102 built in the compressors 11 and 12 with oil level detector. , 82b to open and close the open / close valve 91 and return the reserve oil to the compressors 11 and 12 with oil level detectors to ensure the oil level in the plurality of compressors 11 and 12 with oil level detectors. And the reliability of the refrigeration cycle can be improved.

(Embodiment 3)
In FIG. 3, a plurality of outdoor units B1a and B1b are connected to a plurality of indoor units A1 and A2 via liquid pipes 41 and gas pipes 51, an accumulator 61, a compressor 11 with an oil level detector, and a condenser 21. In the refrigeration cycle in which the expansion devices 31 are sequentially connected by refrigerant piping, an oil separator 71 with an oil tank is interposed between the compressor 11 with an oil level detector and the condenser 21.

  The separator 71 with an oil tank is installed between the outlet of the compressor 11 with an oil level detector and the inlet of the condenser 21, and an oil separation mechanism is housed therein, where the refrigerant gas has flowed into the discharge gas. Separate and drop the oil. An oil storage chamber is provided in which dripped oil is introduced and spare oil is stored. The first oil return pipe 81 is provided above the spare oil surface, and the second oil is provided below the spare oil surface. A return pipe 82 is provided.

  When a plurality of indoor units A1 and A2 are connected, a plurality of outdoor units B1a and B1b are connected, and the pipe length becomes long and additional refrigerant is added and there is a concern about a decrease in the oil dilution rate, reserve oil in advance. Since oil is stored, the oil dilution rate is secured. During operation, when the oil level of the compressor 11 with an oil level detector decreases, the second level of the separator 71 with an oil tank of the outdoor unit B1a is determined by information from the oil level detector 101 built in the compressor 11 with an oil level detector. By opening the on-off valve 91 from the oil return pipe 81 and returning the reserve oil to the compressor 11 with the oil level detector, the oil level in the compressor 11 with the oil level detector can be secured, and the refrigeration cycle Reliability can be improved.

  Further, when there is still a concern about a decrease in the oil dilution rate or a decrease in the oil level with only the spare oil in the separator 71 with the oil tank of the outdoor unit B1a, the oil level detector built in the compressor 11 with the oil level detector. By opening the on-off valve 91 from the second oil return pipe 81 of the separator 71 with an oil tank of the outdoor unit B1b according to the information from the 101, the spare oil is returned to the compressor 11 with an oil level detector, thereby A fall can be avoided and the oil level in the compressor 11 with the oil level detector can be secured, and the reliability of the refrigeration cycle can be improved.

(Embodiment 4)
In FIG. 4, a plurality of outdoor units B2a and B2b are connected to a plurality of indoor units A1 and A2 via liquid pipes 41 and gas pipes 51, and accumulators 61 to a plurality of compressors 11 and 12 with oil level detectors. → Condenser 21 → In a refrigeration cycle in which the expansion device 31 is sequentially connected by refrigerant piping, an oil separator 71 with an oil tank is interposed between a plurality of compressors 11, 12 with oil level detectors and the condenser 21. Has been.

  This separator 71 with an oil tank is installed between the junction from the outlet of the compressor 11 with the oil level detector and the outlet of the compressor 12 with the oil level detector and the inlet of the condenser 21, and the oil separation mechanism is housed therein. Here, the refrigerant gas separates and drops the oil that has flowed into the discharge gas. An oil storage chamber is provided in which dripped oil is introduced and spare oil is stored. The first oil return pipe 81 is provided above the spare oil surface, and the second oil is provided below the spare oil surface. Return pipes 82a and 82b are provided.

  If a plurality of indoor units A1 and A2 are connected, a plurality of outdoor units B2a and B2b are connected, and the pipe length becomes long and additional refrigerant is added and there is a concern about a decrease in the oil dilution rate, reserve oil in advance. Since oil is stored, the oil dilution rate is secured. When the oil level of the compressors 11 and 12 with the oil level detector is lowered during operation, the oil tank of the outdoor unit B2a is attached according to information from the oil level detectors 101 and 102 built in the compressors 11 and 12 with the oil level detector. By opening the on-off valve 91 from the second oil return pipes 82a and 82b of the separator 71 and returning the spare oil to the compressors 11 and 12 with the oil level detector, a plurality of compressors 11 with the oil level detector, The oil level at 12 can be ensured, and the reliability of the refrigeration cycle can be improved.

  In addition, when there is still a concern about a decrease in the oil dilution rate or a decrease in the oil level with only the spare oil of the separator 71 with an oil tank of the outdoor unit B2a, the second oil return of the separator 71 with an oil tank of the outdoor unit B2b. The on-off valve 91 is opened by the information from the oil level detectors 101, 102 built in the compressors 11, 12 with oil level detectors through the pipes 82a, 82b, and the spare oil is returned to the compressors 11, 12 with oil level detectors. As a result, it is possible to avoid a decrease in the oil dilution rate and to secure the oil level in the compressors 11 and 12 with the oil level detector, and to improve the reliability of the refrigeration cycle.

  In the embodiment described above, two compressors with oil level detectors are shown, but three or more compressors may be used. The same applies to the case where the compressors with oil level detectors have different capabilities.

  This embodiment has been described on the premise that the refrigerant R22 currently used for an air conditioner and the like and the oil compatible with the refrigerant R22 are used. However, the present embodiment can also be applied to the HFC mixed refrigerant and the oil compatible with the refrigerant.

  As described above, the air conditioner according to the present invention has an oil tank separator interposed between the compressor outlet with an oil level detector and the condenser inlet, so that the number of indoor units and the number of indoor units can be increased. Compressing with an oil level detector that lacks oil while securing the oil dilution rate while using a compressor with an oil level detector in the refrigeration cycle for additional refrigerant replenishment due to changes or changes in the number of outdoor units It is possible to reliably return the oil to the machine.

System diagram showing an air conditioner showing Embodiment 1 of the present invention System diagram showing an air conditioner showing Embodiment 2 of the present invention System diagram showing an air conditioner showing Embodiment 3 of the present invention System diagram showing an air conditioner showing Embodiment 4 of the present invention System diagram showing a conventional air conditioner

Explanation of symbols

A, A1, A2 Indoor unit B, B1a, B1b, B2a, B2b Outdoor unit 1, 11, 12 Compressor with oil level detector 2, 21 Condenser 3, 31 Throttle device 4, 41 Liquid pipe 5, 51 Gas pipe 6, 61 Accumulator 7 Oil separator 71 Oil tank separator 8, 81, 82, 82a, 82b Oil return pipe 91 On-off valve 101, 102 Oil level detector

Claims (3)

Compressor, condenser, throttling device, and evaporator have a refrigeration cycle connected to piping in sequence, distribute the components to indoor units and outdoor units, and connect multiple indoor units and outdoor units that can be connected In the separate air-conditioner connected with, the oil reservoir function is provided, and oil reservoirs with oil return ports at the upper and lower parts of the oil storage part are provided in the pipeline connecting the compressor with the oil level detector and the condenser. Air conditioner characterized by. Multiple compressors with oil level detectors connected in parallel to the outdoor unit, equipped with an oil separator function, from the oil return port at the bottom of the oil sump container with oil return ports at the top and bottom of the oil reservoir 2. The air conditioner according to claim 1, wherein a circuit is provided in each suction pipe of the compressor with an oil level detector. The air conditioner according to claim 1 or 2, wherein a plurality of outdoor units are connected in parallel.