VAPOR COMPRESSION REFRIGERATING SYSTEMS
A vapor compression refrigerating system includes a compressor, a radiator connected to the compressor via a first tube, a first pressure reducing mechanism connected to the radiator via a second tube, and a separator connected to the first pressure reducing mechanism via a third tube and the compressor via a fourth tube. The separator includes an oil separator which is configured to separate an oil from the refrigerant, and a liquid and gas separator formed integral with the oil separator. The liquid and gas separator is configured to separate a liquid portion and a gas portion from the refrigerant, and the separator is further configured to transmit the oil and the gas portion to the compressor via the fourth tube. The system also includes a second pressure reducing mechanism connected to the separator via a fifth tube, and an evaporator connected to the second pressure reducing mechanism via a sixth tube and operationally coupled to the compressor via a seventh tube. The second pressure reducing mechanism is configured to receive the liquid portion from the separator.
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1. Field of the Invention
The present invention relates generally to vapor compression refrigerating systems. In particular, the present invention relates to vapor compression refrigerating systems in which a separator includes an oil separator integrated with a gas and liquid separator to form a single separator, and a gas portion of a refrigerant and an oil separated from the refrigerant flows from the separator to a compressor via the same tube, such that the size and the weight of the vapor compression refrigerating systems is reduced.
2. Description of Related Art
Freon group refrigerants have been used in known air conditioning systems, Nevertheless, the use such Freon group refrigerants has begun to be restricted due to environmental concerns. In Europe, it has been proposed that carbon dioxide be used as a refrigerant in place of Freon. Carbon dioxide refrigerant is poison less and incombustible, however, the theoretical energy efficiency of carbon dioxide as a refrigerant is relatively low, there are problems associated with improving the efficiency of carbon dioxide as a refrigerant. Moreover, when carbon dioxide is used as a refrigerant, because a high-pressure side may reach a super critical condition which exceeds a critical pressure, it is necessary to use materials that may bear this pressure. Consequently, the thickness of the materials increases, which increases the weight of the air conditioner system.
One known method of improving the efficiency of carbon dioxide as a refrigerant, which is described in Japanese Patent Publication No. JP-A-2000-274890, is to use an oil separator to prevent the circulation of oil to components other than the compressor. Nevertheless, the oil separator increases the size of the air conditioner. Moreover, if oil flows into the evaporator, its heat transfer coefficient and its coefficient of heat exchange are reduced.
SUMMARY OF THE INVENTIONTherefore, a need has arisen for vapor compression refrigerating systems which overcome these and other shortcomings of the related art. A technical advantage of the present invention is that a separator may comprise an oil separator integrated with a gas and liquid separator to form a single separator, and a gas portion of the refrigerant and an oil separated from the refrigerant may flow from the separator to a compressor via the same tube, such that the size and the weight of the vapor compression refrigerating system may be reduced relative to the known vapor compression refrigerating systems.
According to an embodiment of the present invention, a vapor compression refrigerating system comprises a compressor configured to compress a refrigerant, and a radiator connected to the compressor via a first tube. The radiator is configured to receive the refrigerant from the compressor and to radiate the refrigerant. The system also comprises a first pressure reducing mechanism connected to the radiator via a second tube, and the first pressure reducing mechanism is configured to receive the refrigerant from the radiator and to reduce a pressure of the refrigerant. Moreover, the system comprises a separator connected to the first pressure reducing mechanism via a third tube and the compressor via a fourth tube, and the separator is configured to receive the refrigerant from the first pressure reducing mechanism. The separator comprises an oil separator which is configured to separate an oil from the refrigerant, and a liquid and gas separator formed integral with the oil separator. The liquid and gas separator is configured to separate a liquid portion and a gas portion from the refrigerant, and the separator is further configured to transmit the oil and the gas portion to the compressor via the fourth tube. The system also comprises a second pressure reducing mechanism connected to the separator via a fifth tube, and the second pressure reducing mechanism is configured to receive the liquid portion from the separator and to reduce a pressure of the liquid portion. Moreover, the system comprises an evaporator connected to the second pressure reducing mechanism via a sixth tube and operationally coupled to the compressor via at least a seventh tube. The evaporator is configured to receive the liquid portion from the second pressure reducing mechanism and to evaporate the liquid portion.
Other objects, features, and advantage will be apparent to persons of ordinary skill in the art from the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGSFor a more complete understanding of the present invention, needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following description taken in connection with the accompanying drawings.
Embodiments of the present invention, and their features and advantages, may be understood by referring to
In operation, a refrigerant, such as a carbon dioxide refrigerant, may be compressed by compressor 1, which contracts the refrigerant and increases the temperature of the refrigerant. The refrigerant then may flow from compressor 1 to radiator 2, and radiator 2 may radiate the refrigerant to decrease the temperature of the refrigerant. The refrigerant then may flow from radiator 2 to first pressure reducing mechanism 3, and first pressure reducing mechanism 3 may expand the refrigerant and may reduce the pressure of the refrigerant. The refrigerant then may flow from first pressure reducing mechanism 3 to separator 4, and separator 4 may separate the refrigerant into a gas portion and a liquid portion, and may separate an oil from the refrigerant. For example, the oil may be separated from the refrigerant by centrifugal separation or collision separation. The oil and the gas portion then may flow from separator 4 to compressor 1, such that the oil and the gas portion flow from separator 4 to compressor 1 via the same tube 7. Nevertheless, the liquid portion may flow from separator 4 to second pressure reducing mechanism 5, and second pressure reducing mechanism 5 may further expand and further reduce the pressure of the liquid portion. The liquid portion then may flow from second pressure reducing mechanism 5 to evaporator 6, and evaporator 6 may evaporate the liquid portion into a gas. The gas then may flow from evaporator 6 to compressor 7.
In the above-described embodiment of the present invention, because separator 4 may comprise an oil separator integrated with a gas and liquid separator to form a single separator, and/or because the gas portion of the refrigerant and the oil may flow from separator 4 to compressor 1 via the same tube 7, the size and/or the weight of the vapor compression refrigerating system may be reduced.
Referring to
Referring to
The vapor compression refrigerating system according to the present invention may be particularly suitable for an air conditioning system of a vehicle, such as an air conditioning system which uses carbon dioxide as a refrigerant.
While the invention has been described in connection with embodiments of the invention, it will be understood by those skilled in the art that variations and modifications of the embodiments described above may be made without departing from the scope of the invention. Other embodiments will be apparent to those skilled in the art from a consideration of the specification or from a practice of the invention disclosed herein. It is intended that the specification and the described examples are consider exemplary only, with the true scope of the invention indicated by the following claims.
Claims
1. A vapor compression refrigerating system comprising:
- a compressor configured to compress a refrigerant;
- a radiator connected to the compressor via a first tube, wherein the radiator is configured to receive the refrigerant from the compressor and to radiate the refrigerant;
- a first pressure reducing mechanism connected to the radiator via a second tube, wherein the first pressure reducing mechanism is configured to receive the refrigerant from the radiator and to reduce a pressure of the refrigerant;
- a separator connected to the first pressure reducing mechanism via a third tube and the compressor via a fourth tube, wherein the separator is configured to receive the refrigerant from the first pressure reducing mechanism, and the separator comprises: an oil separator which is configured to separate an oil from the refrigerant; and a liquid and gas separator formed integral with the oil separator, wherein the liquid and gas separator is configured to separate a liquid portion and a gas portion from the refrigerant, and the separator is further configured to transmit the oil and the gas portion to the compressor via the fourth tube;
- a second pressure reducing mechanism connected to the separator via a fifth tube, wherein the second pressure reducing mechanism is configured to receive the liquid portion from the separator and to reduce a pressure of the liquid portion; and
- an evaporator connected to the second pressure reducing mechanism via a sixth tube and operationally coupled to the compressor via at least a seventh tube, wherein the evaporator is configured to receive the liquid portion from the second pressure reducing mechanism and to evaporate the liquid portion.
2. The vapor compression refrigerating system of claim 1, wherein the evaporator is connected to the compressor via the separator, and the evaporator is configured to receive the liquid portion from the second pressure reducing mechanism and to evaporate the liquid portion into an evaporated portion and to transmit the evaporated portion to the separator, wherein the system further comprises means for exchanging heat between the liquid portion and evaporated portion.
3. The vapor compression refrigerating system of claim 1, wherein the oil separator comprises at least one of a centrifugal oil separator and a collision oil separator.
4. The vapor compression refrigerating system of claim 1, wherein the first pressure reducing mechanism is configured to control a pressure of the refrigerant at an exit side of the first pressure reducing mechanism to be less than or equal to a critical pressure.
5. The vapor compression refrigerating system of claim 1, wherein at least one of the first pressure reducing mechanism and the second pressure reducing mechanism comprises a mechanical expansion valve which changes a degree of expansion in response to at least one of a temperature and a pressure of the refrigerant.
6. The vapor compression refrigerating system of claim 1, wherein at least one of the first pressure reducing mechanism and the second pressure reducing mechanism comprises an electronic expansion valve which changes an opening degree of a valve by an electric signal in response to at least one of a temperature and a pressure of the refrigerant.
7. The vapor compression refrigerating system of claim 1, wherein the refrigerant comprises carbon dioxide.
8. An air conditioning system comprising a vapor compression refrigerating system, wherein the vapor compression refrigerating system comprises:
- a compressor configured to compress a refrigerant;
- a radiator connected to the compressor via a first tube, wherein the radiator is configured to receive the refrigerant from the compressor and to radiate the refrigerant;
- a first pressure reducing mechanism connected to the radiator via a second tube, wherein the first pressure reducing mechanism is configured to receive the refrigerant from the radiator and to reduce a pressure of the refrigerant;
- a separator connected to the first pressure reducing mechanism via a third tube and the compressor via a fourth tube, wherein the separator is configured to receive the refrigerant from the first pressure reducing mechanism, and the separator comprises: an oil separator which is configured to separate an oil from the refrigerant; and a liquid and gas separator formed integral with the oil separator, wherein the liquid and gas separator is configured to separate a liquid portion and a gas portion from the refrigerant, and the separator is further configured to transmit the oil and the gas portion to the compressor via the fourth tube;
- a second pressure reducing mechanism connected to the separator via a fifth tube, wherein the second pressure reducing mechanism is configured to receive the liquid portion from the separator and to reduce a pressure of the liquid portion; and
- an evaporator connected to the second pressure reducing mechanism via a sixth tube and operationally coupled to the compressor via at least a seventh tube, wherein the evaporator is configured to receive the liquid portion from the second pressure reducing mechanism and to evaporate the liquid portion.
9. A vehicle comprising an air conditioning system, wherein the air conditioning system comprises a vapor compression refrigerating system, and the vapor compression refrigerating system comprises:
- a compressor configured to compress a refrigerant;
- a radiator connected to the compressor via a first tube, wherein the radiator is configured to receive the refrigerant from the compressor and to radiate the refrigerant;
- a first pressure reducing mechanism connected to the radiator via a second tube, wherein the first pressure reducing mechanism is configured to receive the refrigerant from the radiator and to reduce a pressure of the refrigerant;
- a separator connected to the first pressure reducing mechanism via a third tube and the compressor via a fourth tube, wherein the separator is configured to receive the refrigerant from the first pressure reducing mechanism, and the separator comprises: an oil separator which is configured to separate an oil from the refrigerant; and a liquid and gas separator formed integral with the oil separator, wherein the liquid and gas separator is configured to separate a liquid portion and a gas portion from the refrigerant, and the separator is lurer configured to transmit the oil and the gas portion to the compressor via the fourth tube;
- a second pressure reducing mechanism connected to the separator via a fifth tube, wherein the second pressure reducing mechanism is configured to receive the liquid portion from the separator and to reduce a pressure of the liquid portion; and
- an evaporator connected to the second pressure reducing mechanism via a sixth tube and operationally coupled to the compressor via at least a seventh tube, wherein the evaporator is configured to receive the liquid portion from the second pressure reducing mechanism and to evaporate the liquid portion.
Type: Application
Filed: Dec 12, 2006
Publication Date: Jun 14, 2007
Applicant: SANDEN CORPORATION (Isesaki-shi)
Inventors: Yuuichi Matsumoto (Isesaki-shi, Gunma), Masato Tsuboi (Isesaki-shi, Gunma), Kenichi Suzuki (Isesaki-shi, Gunma)
Application Number: 11/609,617
International Classification: F25B 43/02 (20060101); F25B 43/00 (20060101); F25B 41/00 (20060101);