JP4192314B2 - Supercritical refrigeration cycle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressor, and is effective when applied to a compressor for a supercritical refrigeration cycle in which the refrigerant pressure on the high pressure side (radiator side) is equal to or higher than the critical pressure of the refrigerant.
[0002]
[Prior art]
The compression mechanism of the compressor as a means of lubricating, for example in Japanese Utility Model 59-1199 9 In the invention described in 2 JP-oil separator for separating lubricating oil from the refrigerant (fluid) flowing out of the compression mechanism (oil separator) The lubricating oil separated by the oil separator and stored in the oil storage part is returned to the suction side of the compression mechanism using the differential pressure between the discharge pressure and the suction pressure.
[0003]
[Problems to be solved by the invention]
By the way, in the supercritical refrigeration cycle, the discharge pressure is about 10 times higher than the refrigeration cycle using chlorofluorocarbon as a refrigerant (hereinafter, this refrigeration cycle is referred to as the chlorofluorocarbon cycle). It is about 5-8 times as large as the cycle.
For this reason, as described in the above publication, if the lubricating oil is simply supplied to the compression mechanism using the differential pressure between the discharge pressure and the suction pressure, the amount of lubricating oil supplied to the compression mechanism increases excessively. Problem occurs.
[0004]
In order to solve this problem, a means is conceivable in which the cross-sectional area of the oil passage connected to the oil storage portion is reduced to prevent an excessive increase in the amount of lubricating oil supplied to the compression mechanism.
However, in the supercritical refrigeration cycle, the differential pressure between the discharge pressure and the suction pressure is as large as about 5 to 8 times that of the Freon cycle. Therefore, simply reducing the passage cross-sectional area of the oil passage makes the passage cross-sectional area excessively small. It is necessary and the oil passage may be clogged. For this reason, lubricating oil cannot be stably supplied to a compression mechanism, and there exists a possibility of impairing the performance and reliability of a compressor.
[0005]
An object of this invention is to supply lubricating oil stably to a compression mechanism in view of the said point.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention uses the following technical means. In the first aspect of the present invention, the compressor (100) that sucks and compresses the refrigerant, the refrigerant discharged from the compressor (100), and the radiator (200) whose internal pressure is equal to or higher than the critical pressure of the refrigerant. ), A decompressor (400) for decompressing the refrigerant flowing out from the radiator (200), and an evaporator (300) for evaporating the refrigerant flowing out from the decompressor (400), and using carbon dioxide as the refrigerant The compressor (100) sucks fluid through the housing (110), the fixed scroll (120) fixed to the housing (110), and the orbiting scroll (130) rotating with respect to the fixed scroll (120). A plurality of working chambers (V) to be compressed are configured, and the working chamber (V) is turned with respect to the fixed scroll (120) in conjunction with the turning of the orbiting scroll (130). A compression mechanism (Cp) for reducing the volume of the working chamber (V), and an oil storage part (210) for separating the lubricating oil from the fluid discharged from the compression mechanism (Cp) and storing the separated lubricating oil. and an oil separator (200), operating the compressor (100), the working chamber (V) and oil storage section (210) and the communication path for communicating (220) is provided with, among communication passage (220) The opening (221) on the outlet side that opens toward the chamber (V) is provided so as to open only at one place, and the opening (221) is a plurality of working chambers (V). The internal pressure (P) communicates with a predetermined working chamber (Vo) that changes from a predetermined pressure (Po) lower than the pressure (Pd) of the oil storage part (210) to a pressure (Pd) or more of the oil storage part (210). open, the pressure in the oil reservoir portion (210) (Pd) is given Only while higher than the internal pressure of the working chamber (Vo) (P), characterized in that it is provided to supply oil storage unit lubricating oil stored in (210) a predetermined operation chamber to (Vo).
[0007]
Thereby, the lubricating oil in the oil storage part (210) is in a state in which the pressure (Pd) of the oil storage part (210) is higher than the internal pressure (P) of the working chamber (V) among the plurality of working chambers (V). because it is supplied only to a predetermined operating chamber (V o) which is made, rather than always oil storage section from (210) the lubricating oil is supplied to the compression mechanism (Cp), intermittently lubricating oil compression mechanism ( Cp).
[0008]
Therefore, it is possible to prevent an excessive increase in the amount of lubricating oil supplied to the compression mechanism (Cp) without reducing the passage cross-sectional area of the communication passage (220), and thus the passage cross-sectional area of the communication passage (220). There is no need to reduce the size. As a result, it is possible to prevent the communication path (220) from being clogged with foreign matter, so that the lubricating oil can be stably supplied to the compression mechanism (Cp), and the performance and reliability of the compressor can be improved. .
[0009]
In addition, since it is not necessary to form the communication passage (220) having a small passage cross-sectional area, the communication passage (220) can be easily formed, so that the manufacturing cost of the compressor can be reduced.
According to a second aspect of the present invention, in the supercritical refrigeration cycle according to the first aspect, the rotary scroll (130) is provided with a shaft (140) for rotationally driving, and the fixed scroll (120) has two windings. The number of turns of the orbiting scroll (130) is 1.5 and when the rotation angle (θ) of the shaft (140) when the working chamber (V) becomes a closed space is 0 °, the opening portion (221) is characterized in that it communicates with the predetermined working chamber (Vo) only during a period (Θo) until the rotation angle (θ) of the shaft (140) reaches 300 ° to 600 °.
Incidentally, the reference numerals in parentheses of each means described above are an example showing the correspondence with the specific means described in the embodiments described later.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In this embodiment, the compressor 100 according to the present invention is applied to a compressor for a supercritical refrigeration cycle for a vehicle air conditioner, and FIG. 1 is a schematic diagram of the supercritical refrigeration cycle.
In FIG. 1, reference numeral 100 denotes a scroll compressor (hereinafter abbreviated as a compressor) that sucks refrigerant (carbon dioxide) and compresses the sucked refrigerant to a critical pressure or higher of the refrigerant. Details will be described later. .
[0011]
200 is an outdoor heat exchanger (heat radiator) that cools the refrigerant by exchanging heat between the outdoor air and the refrigerant, and 300 is a heat exchanger that evaporates the refrigerant by exchanging heat between the indoor air blown into the room and the refrigerant. It is an indoor heat exchanger (evaporator). A decompressor 400 that decompresses the refrigerant is provided between the indoor heat exchanger 300 and the outdoor heat exchanger 200.
[0012]
Note that the decompressor 400 is the same as the pressure control valve described in Japanese Patent Application No. 8-33962, so detailed description of the decompressor 400 is omitted in this specification.
On the suction side of the compressor 100, an accumulator (gas-liquid separation means) 500 that separates the refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant and discharges the gas-phase refrigerant toward the suction side of the compressor 100. Is provided. Reference numeral 600 denotes an internal heat exchanger that exchanges heat between the refrigerant that exists between the accumulator 600 and the compressor 100 and the refrigerant that exists between the outdoor heat exchanger 200 and the decompressor 400.
[0013]
Next, the compressor 100 will be described with reference to FIG.
Reference numeral 111 denotes a front housing to which a fixed scroll (fixed portion) 120 is fixed. Reference numeral 130 denotes a orbiting scroll (movable part) that is orbitably movable with respect to the fixed scroll 120. Both scrolls 120 and 130 have spiral scroll teeth that form a plurality of working chambers V through which refrigerant (fluid) is sucked. Portions 121 and 131 are formed.
[0014]
In this embodiment, the compression mechanism Cp that sucks and compresses the refrigerant is configured by enlarging and reducing the volume of the working chamber V formed by the scrolls 120 and 130. Reference numeral 113 denotes a suction port connected to the inflow side of the indoor heat exchanger 300, and reference numeral 114 denotes a discharge port connected to the inflow side of the outdoor heat exchanger 200.
Reference numeral 140 denotes a shaft that orbits the orbiting scroll 130. The shaft 140 passes through the inside and outside of the front housing 111, and one end side (the left side of the drawing) is exposed outside the front housing 111. In the present embodiment, the shaft 140 is driven by a vehicle travel engine (not shown) via an electromagnetic clutch (not shown) connected to one end of the shaft 140 (a portion exposed outside the front housing 111). Driven by rotation.
[0015]
A rolling bearing (hereinafter abbreviated as a bearing) 150 that rotatably supports the shaft 140 is disposed in the front housing 111. In the vicinity of the bearing 150, the gap between the shaft 140 and the front housing 111 is sealed on the electromagnetic clutch side (one end side of the shaft 140) from the bearing 150, and a refrigerant or the like is placed outside the front housing 111 (compressor 100). A lip seal 160 is provided to prevent the lubricating oil from flowing out.
[0016]
In addition, the orbiting scroll 130 is connected to the other end side of the shaft 140 (the right side in the drawing) via a bearing 170 at a portion eccentric from the rotation center of the shaft 140. Reference numeral 180 denotes a well-known pin-ring type anti-rotation mechanism that prevents the orbiting scroll 130 from rotating. When the shaft 140 rotates by the anti-rotation mechanism 180, the orbiting scroll 130 does not rotate but rotates around the shaft 140. (Revolution).
[0017]
Reference numeral 132 denotes a balancer that cancels out eccentric force (centrifugal force generated in the orbiting scroll 130) acting on the shaft 140 as the orbiting scroll 130 rotates.
Reference numeral 190 denotes a discharge chamber that smoothes the pulsation of the refrigerant discharged from the working chamber V, and reference numeral 191 denotes a discharge port that allows the working chamber V and the discharge chamber 190 to communicate with each other. 192 is a reed valve-like discharge valve (check valve) that prevents the refrigerant from flowing back from the discharge chamber 190 to the working chamber V, and 193 is a stopper that regulates the maximum opening of the discharge valve 192.
[0018]
Reference numeral 200 denotes an oil separator (oil separator) that separates lubricating oil from the refrigerant discharged from the compression mechanism Cp and has an oil storage section that stores the separated lubricating oil. And since the oil separator 200 (oil storage part 210) is connected to the discharge chamber 190, the internal force is substantially equal to the pressure in the discharge chamber 190 (discharge pressure Pd of the compression mechanism Cp). Therefore, hereinafter referred to pressure in savings oil unit 210 and the oil storage section pressure Pd.
[0019]
The discharge chamber 190, the oil separator 200, and the oil storage unit 210 are formed in the rear housing 112 fixed to the fixed scroll 120. The front housing 111, the outermost periphery of the fixed scroll 120, and the rear housing 112 constitute a housing 110 of the compressor 100. Incidentally, the oil separator 200 rotates the refrigerant containing the lubricating oil around the separation pipe part 201 by blowing the refrigerant containing the lubricating oil from the discharge chamber 190 toward the outer peripheral surface of the separation pipe part 201 continuous from the discharge port 114. is allowed even for a is the centrifugal separation type for separating the more the lubricant to the centrifugal force.
[0020]
An oil passage (communication passage) 220 is formed in the end plate portion 122 of the fixed scroll 120 to connect the oil storage portion 210 and the working chamber V to guide the lubricating oil to the working chamber V. The outlet 221 of the oil passage 220 that opens toward the working chamber V has an oil storage section internal pressure Pd from a predetermined pressure Po of the plurality of working chambers V whose internal pressure P is lower than the oil storage section internal pressure Pd. It opens so that it may communicate with the predetermined working chamber V which changes so far.
[0021]
Next, the characteristic operation of this embodiment will be described.
As is well known, the compression mechanism Cp of the scroll compressor causes the working chamber V formed outside the spirals of the scroll tooth portions 121 and 131 to perform the orbiting motion of the orbiting scroll 130 as shown in FIGS. In conjunction with this, the volume is reduced and the refrigerant (fluid) is compressed while approaching the center of the spiral while turning with respect to the fixed scroll 120.
[0022]
Incidentally, in FIGS. 3 to 14, the rotation angle θ of the shaft 140 when the suction of the refrigerant is completed (when the working chamber V formed on the outer side of the spiral becomes a closed space) is set to 0 ° (FIG. 3). ) Shows the state of the scrolls 120 and 130 every time the rotation of the shaft 140 advances by 60 °. Here, when attention is paid to a change in pressure in one working chamber V (hereinafter, this working chamber is expressed as working chamber Vo) among the plurality of compression mechanisms Cp, as shown in FIG. As the shaft 140 rotates, the pressure increases from the suction pressure Ps of the compression mechanism Cp toward the discharge pressure Pd. When the internal pressure of the working chamber Vo rises to the discharge pressure Pd or more and the working chamber Vo communicates with the discharge port 191 (see FIGS. 8 to 14), the refrigerant in the working chamber Vo is directed to the radiator 200. Discharged.
[0023]
Incidentally, the openings 221, among the plurality of working chambers V, since the internal pressure P is opened so as to communicate with the predetermined operation chamber V o varying from pressure Po to the pressure Pd or the oil storage portion, FIG 3 as is clear from 14, rather than always communicates with the working chamber Vo, the second predetermined angle (present from the time the rotation angle θ of the shaft 140 that becomes the first predetermined angle (300 ° in this embodiment) .theta.1 In the embodiment, it is in communication with the working chamber Vo only during the period Θo until the time when it becomes θ2 (600 °) (see FIGS. 8 to 12).
[0024]
On the other hand, the lubricating oil in the oil storage section 210 is supplied to the working chamber Vo when the oil storage section internal pressure Pd is higher than the internal pressure P in the working chamber Vo. During the communicating period Θo, the oil reservoir internal pressure Pd is supplied to the working chamber Vo only while it is higher than the internal pressure P of the working chamber Vo.
That is, in the compressor 100 according to the present embodiment, the lubricating oil is not always supplied from the oil storage unit 210 to the compression mechanism Cp (working chamber V), but is intermittently lubricated as shown in FIG. Oil will be supplied to the compression mechanism Cp.
[0025]
As is clear from the above description of the operation, the amount of lubricating oil supplied to the compression mechanism Cp depends on the position of the opening 221 (time during which the opening 221 is in communication with the working chamber Vo) and the internal pressure of the working chamber Vo. Since it varies depending on the degree of increase in P (suction pressure Ps) and the discharge pressure Pd, it is necessary to select the position of the opening 221 in consideration of the load of the compressor 100 (discharge pressure Pd and suction pressure Ps). There is.
[0026]
Incidentally, when the oil storage section internal pressure Pd becomes equal to or lower than the internal pressure P of the working chamber Vo, the refrigerant in the working chamber Vo flows into the oil storage section 210 without passing through the discharge chamber 190, but the oil storage section internal pressure Pd is reduced. Immediately after the pressure becomes equal to or lower than the internal pressure P0 of Vo, the discharge port 191 opens, so that the amount of refrigerant flowing into the oil storage section 210 without passing through the discharge chamber 190 is very small, and there is almost no problem in practical use.
[0027]
Next, features of the present embodiment will be described.
As apparent from the above description of the operation, since the lubricating oil can be intermittently supplied to the compression mechanism Cp, the amount of the lubricating oil supplied to the compression mechanism Cp without reducing the cross-sectional area of the oil passage 220. Can be prevented from increasing excessively. Therefore, since it is not necessary to reduce the cross-sectional area of the oil passage 220, it is possible to prevent the oil passage 220 from being clogged with foreign matter.
[0028]
As a result, since the lubricating oil can be stably supplied to the compression mechanism Cp, the performance and reliability of the compressor 100 can be improved.
In addition, since it is not necessary to form the oil passage 220 having a small passage cross-sectional area, the oil passage 220 can be easily formed, so that the manufacturing cost of the compressor 100 can be reduced.
[0030]
By the way, the form of the oil passage 220 is not limited to the above embodiment , and the lubricating oil in the oil storage part 210 is supplied to the working chamber via the end plate part 122 of the fixed scroll 120 and the scroll tooth part 131 of the orbiting scroll 130. The oil passage 200 may be configured so as to be guided to V.
[0031]
Further, a check valve that prevents the refrigerant from flowing from the working chamber V to the oil storage unit 210 may be provided in the oil passage 220.
Furthermore, in the above-described embodiment, the compression mechanism Cp and the oil separator 200 are integrated. However, the compression mechanism Cp and the oil separator 200 may be separated.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a supercritical refrigeration cycle.
FIG. 2 is a cross-sectional view of the compressor according to the embodiment.
3 is an A-A sectional view of FIG.
4 is an A-A sectional view of FIG.
5 is an A-A sectional view of FIG.
6 is an A-A sectional view of FIG.
7 is an A-A sectional view of FIG.
8 is an A-A sectional view of FIG.
9 is an A-A sectional view of FIG.
It is an A-A sectional view of FIG. 10 FIG.
11 is an A-A sectional view of FIG.
It is an A-A sectional view of FIG. 12 FIG.
13 is an A-A sectional view of FIG.
14 is an A-A sectional view of FIG.
15A is a graph showing the relationship between the rotation angle θ of the shaft and the internal pressure of the working chamber, and FIG. 15B shows the relationship between the rotation angle θ of the shaft and the amount of lubricating oil supplied to the working chamber. It is a graph to show.
[Explanation of symbols]
111 Front housing 112 Rear housing 120 Fixed scroll 130 Orbiting scroll 140 Shaft 150 Bearing 160 Lip seal 200 Oil separator (oil separator)
210 Oil storage section 220 Oil passage (communication passage)

Claims (2)

A compressor (100) for sucking and compressing refrigerant;
A radiator (200) for cooling the refrigerant discharged from the compressor (100) and having an internal pressure equal to or higher than a critical pressure of the refrigerant;
A decompressor (400) for decompressing the refrigerant flowing out of the radiator (200);
An evaporator (300) for evaporating the refrigerant flowing out of the decompressor (400),
Carbon dioxide is used as the refrigerant,
The compressor (100)
A housing (110);
A plurality of working chambers (V) for sucking and compressing fluid are constituted by a fixed scroll (120) fixed with respect to the housing (110) and a turning scroll (130) rotating with respect to the fixed scroll (120). And a compression mechanism (Cp) for reducing the volume of the working chamber (V) while turning the working chamber (V) relative to the fixed scroll (120) in conjunction with the turning of the orbiting scroll (130). When,
An oil separator (200) having an oil reservoir (210) for separating the lubricating oil from the fluid discharged from the compression mechanism (Cp) and storing the separated lubricating oil;
The compressor (100) is provided with a communication path (220) for communicating the working chamber (V) and the oil storage part (210),
Before the opening of the outlet which opens towards the working chamber (V) of Killen passage (220) (221) is provided so as to be opened in only one place,
In addition, the opening (221) is configured so that the oil storage portion of the plurality of working chambers (V) from a predetermined pressure (Po) whose internal pressure (P) is lower than the pressure (Pd) of the oil storage portion (210). The pressure (Pd) of the oil storage section (210) is opened to communicate with a predetermined working chamber (Vo) that changes to a pressure (Pd) or more of (210), and the internal pressure of the predetermined working chamber (Vo) The supercritical refrigeration cycle is provided so as to supply the lubricating oil stored in the oil storage section (210) to the predetermined working chamber (Vo) only during a period higher than (P) . A shaft (140) for orbiting the orbiting scroll (130);
The fixed scroll (120) has two windings,
The number of turns of the orbiting scroll (130) is 1.5,
When the rotation angle (θ) of the shaft (140) when the working chamber (V) becomes a closed space is 0 °,
The opening (221) communicates with the predetermined working chamber (Vo) only during a period (Θo) until the rotation angle (θ) of the shaft (140) reaches 300 ° to 600 °. The supercritical refrigeration cycle according to claim 1, wherein the supercritical refrigeration cycle is open.

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