JP2008196731A - Refrigerating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating apparatus capable of returning a lubricant to a compressor 1 without using a float valve by returning the lubricant accumulated in an oil separator 2 into the compressor 1 by self-weight of the lubricant, being miniaturized by reducing the outer shape of the oil separator 2, and free from degradation of performance even when the compressor 1 is used for a long period. <P>SOLUTION: A sealed container 6 is connected to the oil separator 2 by using a pressure equalizing pipe 17 for making a pressure in the oil separator 2 and a pressure in the sealed container 6 approximately same as each other, and an oil distribution pipe 16 for returning the lubricant separated by the oil separator 2 into the sealed container 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus characterized by separating oil from a refrigerant and lubricating oil using an oil separator and having a return oil structure for returning the lubricating oil from the oil separator to a compressor.

  A conventional refrigeration apparatus of this type will be described with reference to FIG.

  Main components of the refrigeration apparatus shown in FIG. 2 include a compressor 1, an oil separator 2, a radiator 3, a decompression unit 4, and an evaporator 5, and these components are connected to the pipes 11 to 14. Connected.

  Reference numeral 15 denotes an oil return pipe.

  First, the discharge port 8 of the compressor 1 is connected to the oil separator 2 via the discharge pipe 11.

  The oil separator 2 is connected to the inlet of the radiator 3 via the pipe 12.

  A pipe 13 is connected to the outlet of the radiator 3, and is connected to the inlet of the evaporator 5 through the decompression means 4.

  Further, the outlet of the evaporator 5 is connected to the suction port 9 of the compressor 1 via the suction pipe 14.

  The return port 2b of the oil separator 2 is connected to the suction pipe 14 via the oil return pipe 15 as shown in the figure.

  In addition, lubricating oil 1a is sealed in the bottom of the compressor 1 for the purpose of preventing damage to the friction surface of the cylinder and a bearing (not shown).

  Below, operation | movement of the above-mentioned freezing apparatus is demonstrated.

  First, the refrigerant discharged from the discharge port 8 of the compressor 1 flows into the oil separator 2 through the discharge pipe 11.

  An oil separator 2a is provided in the oil separator 2, and the refrigerant flowing into the oil separator 2 is separated into refrigerant and lubricating oil when passing through the oil separator 2a.

  The lubricating oil removed from the refrigerant is stored at the bottom of the oil separator 2.

  When a certain amount or more of the lubricating oil is accumulated, the float valve (not shown) is opened, and the lubricating oil is supplied to the compressor 1 via the oil return pipe 15 attached to the return port 2b and the suction pipe 14. Returned.

  On the other hand, the high-temperature and high-pressure refrigerant that has passed through the oil separator 2 is radiated by the radiator 3 to become a low-temperature and high-pressure refrigerant, and reaches the decompression means 4 through the pipe 13.

  Thereafter, the refrigerant is depressurized by the decompression means 4 and flows into the evaporator 5 as a low-temperature and low-pressure refrigerant.

  The refrigerant that has flowed into the evaporator 5 evaporates in the process of passing through the evaporator 5, and cools the air or the like existing in the peripheral portion by taking the latent heat of evaporation from an external fluid such as air.

  The refrigerant having passed through the evaporator 5 is sucked into the compressor 1 from the suction pipe 14 via the suction port 9 and is compressed again.

As described above, according to the conventional refrigeration apparatus, the lubricating oil can be effectively removed from the refrigerant discharged from the compressor 1 in the oil separator 2, so that the lubricating oil is enclosed in the compressor 1. However, this lubricating oil does not adhere to the inner surfaces of the pipes 12 and 13 on the downstream side of the oil separator 2 and the radiator 3, the decompression means 4, the evaporator 5, and the like. The problem of pressure loss is avoided (see, for example, Patent Document 1).
JP 2000-55488 A

  However, since the conventional configuration requires a float valve (not shown) installed in the oil separator 2 when the lubricating oil accumulated in the oil separator 2 is returned to the compressor 1, the oil separation There was a problem that the outer dimension of the vessel 2 was increased.

  In addition, since sludge generated due to long-term use of the compressor 1 adheres to the valve body of the float valve, the float valve cannot be fully closed, and even when no lubricating oil is accumulated in the oil separator 2, the high-pressure side refrigerant is The phenomenon of leaking to the low pressure side was caused.

  As a result, the refrigerant circulation amount in the refrigeration apparatus is reduced, which causes a problem that the capacity of the refrigeration apparatus is reduced.

  The present invention returns the lubricating oil collected in the oil separator to the compressor without using a float valve by returning the lubricating oil accumulated in the oil separator to the compressor by its own weight. It is an object of the present invention to provide a refrigeration apparatus that reduces the outer shape of the refrigeration apparatus and makes the refrigeration apparatus more compact, and that does not cause a decrease in performance even when the compressor is used for a long time.

  In order to achieve the above object, a refrigeration apparatus according to the present invention includes a compressor that discharges a refrigerant compressed by a compression mechanism in a sealed container filled with lubricating oil from a discharge port provided in the sealed container to the outside of the sealed container. An oil separator that separates the lubricating oil discharged together with the refrigerant from the refrigerant discharged from the discharge port, a radiator that dissipates the refrigerant, a decompression unit that depressurizes the refrigerant, and an evaporator that evaporates the refrigerant Sealed with pressure equalizing piping that connects the pressure in the oil separator and the pressure in the sealed container to approximately the same pressure, and oil feed piping that returns the lubricating oil separated by the oil separator to the sealed container The container and the oil separator are connected.

  By setting it as such a structure, the lubricating oil collected in the oil separator can be returned in a compressor with the own weight of lubricating oil.

  With the above-described configuration, the refrigeration apparatus of the present invention can return the lubricating oil accumulated in the oil separator to the compressor by its own weight, so that the lubricating oil can be supplied to the compressor without using a float valve. It is possible to return oil.

  As a result, the outer shape of the oil separator can be reduced, the refrigeration system can be made compact, and the refrigerant capacity can be reduced due to sludge generated when the compressor is used for a long time. A refrigeration apparatus that does not invite can be provided.

  According to a first aspect of the present invention, there is provided a compressor for discharging a refrigerant compressed by a compression mechanism in a sealed container enclosing lubricating oil from a discharge port provided in the sealed container to the outside of the sealed container, and a refrigerant discharged from the discharge port An oil separator that separates the lubricating oil discharged together with the refrigerant, a radiator that dissipates the refrigerant, a decompression unit that depressurizes the refrigerant, and an evaporator that evaporates the refrigerant are connected in an annular manner, and the oil separator The sealed container and the oil separator are connected using a pressure equalizing pipe that makes the pressure in the sealed container and the pressure in the sealed container substantially the same, and an oil feed pipe that returns the lubricating oil separated by the oil separator to the sealed container. It is to do.

  With this configuration, the lubricating oil accumulated in the oil separator can be returned to the compressor by the weight of the lubricating oil, and the lubricating oil can be returned to the compressor without using the float valve.

  In addition to the above-described invention, the second invention is such that, in particular, the oil separator is installed at a position higher than the oil level of the lubricating oil sealed in the compressor.

  With this configuration, the lubricating oil accumulated in the oil separator can be more efficiently returned to the compressor by its own weight.

  As a result, it is possible to return the lubricating oil to the compressor without using a float valve.

  The third invention is the first and second inventions in particular, and the oil feed pipe is connected to the closed container at a position where one of the communication ports is higher than the oil level of the lubricating oil enclosed in the compressor, and the other The communication port is connected to the oil separator at a position higher than one of the communication ports.

  With this configuration, the lubricating oil does not leak from the compressor when the oil feed pipe and the compressor are connected.

  As a result, it is possible to simplify the installation work of the oil feeding pipe.

  The fourth invention is particularly the third invention, wherein the oil feed pipe is installed at the bottom of the oil separator and the oil feed pipe is installed at the bottom of the oil separator.

  With this configuration, the lubricating oil accumulated in the oil separator can be returned to the compressor by the weight of the lubricating oil, and the lubricating oil can be returned to the compressor without using the float valve.

  The fifth aspect of the invention is to use a refrigerant whose pressure has been increased to a critical pressure or more, particularly as the refrigerant used in the first to fourth aspects of the invention.

  Thereby, since the refrigerant | coolant which flows through a radiator is pressurized more than critical pressure with the compressor, even if it takes heat with a radiator and temperature falls, it does not condense.

Therefore, it becomes easy to form a temperature difference between the refrigerant and the fluid to be heated in the entire radiator, and the heat exchange efficiency can be increased.
(Embodiment 1)
Hereinafter, the refrigeration apparatus in Embodiment 1 of the present invention will be described with reference to the drawings.

  First, FIG. 1 is a circuit diagram of the refrigeration apparatus shown in Embodiment 1 of the present invention.

  In addition, about what fulfill | performs the same function as a prior art, the same code | symbol is attached | subjected and the description is used.

  As shown in FIG. 1, a compressor 1, an oil separator 2, a radiator 3, a decompression unit 4, and an evaporator 5 are connected by pipes 11 to 14.

As the refrigerant, for example, carbon dioxide (CO ₂ ) having a pressure on the high pressure side that is equal to or higher than the critical pressure is used as the refrigerant.

  A discharge port 8 of the compressor 1 is connected to the oil separator 2 via a discharge pipe 11.

  The oil separator 2 is connected to the inlet of the radiator 3 via the pipe 12.

  A pipe 13 is connected to the outlet of the radiator 3, and is connected to the inlet of the evaporator 5 through the decompression means 4.

  Further, the outlet of the evaporator 5 is connected to the suction port 9 of the compressor 1 via the suction pipe 14.

  In addition, the return port 2b of the oil separator 2 is connected to the oil return port 10 of the compressor 1 via the oil feed pipe 16, as shown in the figure. At this time, the return port 2 b of the oil separator 2 corresponds to one connecting port of the oil feeding pipe 16, and the oil returning port 10 corresponds to the other connecting port of the oil feeding pipe 16.

  In addition, lubricating oil 1a is sealed in the bottom of the compressor 1 for the purpose of preventing damage to the friction surface of the cylinder and a bearing (not shown).

  Here, the oil separator 2 is installed at a position higher than the position of the lubricating oil surface accumulated in the lubricating oil reservoir 1b at the bottom of the compressor 1, and the return port 2b provided at the bottom of the oil separator 2 is The oil return pipe 16 is connected to the oil return port 10 provided at a position higher than the above-described lubricating oil surface.

  Further, the return port 2 b is installed at a higher position than the oil return port 10.

  Further, the gas phase portion in the oil separator 2 and the gas phase portion in the compressor 1 are connected by a pressure equalizing pipe 17, and the compressor 1 includes a compression mechanism portion 7 in the sealed container 6.

  The operation of the above-described refrigeration apparatus will be described below.

  The refrigerant compressed by the compression mechanism 7 inside the compressor 1 is once discharged into the sealed container 6 and flows out from the discharge port 8 to the oil separator 2 through the discharge pipe 11.

  And a refrigerant | coolant is isolate | separated into a refrigerant | coolant and lubricating oil, when passing the oil separation part 2a in the oil separator 2. FIG.

  At this time, the pressure in the airtight container 6 and the pressure in the oil separator 2 become substantially the same pressure due to the refrigerant flowing from the pressure equalizing pipe 17.

  Therefore, there is almost no refrigerant flow in the oil feed pipe 16.

  The oil separator 2 is installed at a position higher than the lubricating oil surface position in the compressor 1.

  As a result, the lubricating oil removed from the refrigerant in the oil separator 2 falls by its own weight along the oil separator 2 and the inner wall of the oil separator 2, and eventually reaches the bottom of the oil separator 2. .

  Furthermore, since the pressure in the sealed container 6 and the pressure in the oil separator 2 are almost the same pressure, the lubricating oil that has reached the bottom of the oil separator 2 returns by its own weight through the oil feed pipe 16 from the return port 2b. The lubricating oil reservoir 1b is reached through the oil port 10.

  On the other hand, the high-temperature and high-pressure refrigerant that has passed through the oil separator 2 is radiated by the radiator 3 to heat an external fluid such as water or air.

  Thereafter, it flows out from the radiator 3 as a low-temperature and high-pressure refrigerant and reaches the decompression means 4 through the pipe 13.

  The decompression means 4 decompresses the refrigerant and flows into the evaporator 5 as a low-temperature and low-pressure refrigerant.

  The decompressed refrigerant evaporates in the process of passing through the evaporator 5, and cools the surrounding air by taking away the latent heat of evaporation from the external fluid such as air.

  Then, the refrigerant that has flowed out of the evaporator 5 is sucked into the compressor 1 through the suction pipe 14 through the suction port 9, and is compressed again.

  As is clear from the above description, the lubricating oil accumulated in the oil separator 2 is returned to the compressor 1 by its own weight, so that the lubricating oil is returned to the compressor 1 without using a float valve. Oil can be done.

  Therefore, it is possible to make the refrigeration apparatus compact by reducing the outer shape of the oil separator 2, and it is possible to provide a refrigeration apparatus that does not cause a decrease in performance even when the compressor is used for a long time.

  The refrigeration apparatus of the present invention can be used as a housing air conditioner, a building air conditioner, a vehicle air conditioner, or a refrigerator of a heat pump water heater, or as a refrigerator such as a refrigerator, a showcase or a vending machine. Is available.

Circuit diagram of a refrigeration apparatus in an embodiment of the present invention Circuit diagram of conventional refrigeration equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Oil separator 2a Oil separation part 3 Radiator 4 Pressure reducing means 5 Evaporator 6 Sealed container 7 Compression mechanism part 11 Discharge piping 16 Oil feed pipe 17 Pressure equalizing pipe

Claims (5)

A compressor that discharges the refrigerant compressed by the compression mechanism in the sealed container enclosing the lubricating oil from a discharge port provided in the sealed container to the outside of the sealed container, and a refrigerant discharged from the discharge port. An oil separator that separates the lubricating oil discharged together with the refrigerant, a radiator that dissipates the refrigerant, a decompression unit that depressurizes the refrigerant, and an evaporator that evaporates the refrigerant are connected in an annular manner, and the oil separation The sealed container using a pressure equalizing pipe in which the pressure in the container and the pressure in the sealed container are substantially the same, and an oil feed pipe for returning the lubricating oil separated by the oil separator into the sealed container And the oil separator are connected to each other. The refrigeration apparatus according to claim 1, wherein the oil separator is installed at a position higher than an oil level height of the lubricating oil sealed in the compressor. The oil feed pipe is connected to the sealed container at a position where one communication port is higher than the oil level of the lubricating oil sealed in the compressor, and the other communication port is higher than the one communication port. The refrigeration apparatus according to claim 1, wherein the refrigeration apparatus is connected to the oil separator at a position. The refrigeration apparatus according to claim 3, wherein the oil feed pipe is installed at the bottom of the oil separator. The refrigerating apparatus according to any one of claims 1 to 4, wherein a refrigerant used at a critical pressure or higher is used as the refrigerant.

Images