The present disclosure relates to a compressor and a compressor system.
In a compressor, if the compressor is overheated by a compressed gas having a high temperature and a high pressure, the density of a gas to be compressed sucked into the compressor decreases, causing a decrease in efficiency of the compressor. Therefore, for example, in a reciprocating compressor, as a means for suppressing overheating of the compressor, a pipe for flowing cooling water is provided inside a crankcase or a head cover. For example, Patent Document 1, 2 discloses a configuration for suppressing overheating by injecting a refrigerant liquid into a discharge space in a head cover and cooling a compressed discharge gas with latent heat of vaporization of the refrigerant liquid.
Patent Document 1: JP2010-53765A
Patent Document 2: JP2011-163192A
According to the configuration disclosed in Patent Document 1, 2, it is possible to cool the discharge gas, and it is possible to suppress overheating of the compressor. However, due to an influence of cooling, a large amount of frost may occur on a surface of the compressor (for example, a surface of the head cover or the casing). Such configuration where the large amount of frost occurs is not preferable.
The present disclosure has been made in view of the above-described problems, and the object of the present disclosure is to suppresses the occurrence of frost on the surface of the compressor when the compressed discharge gas is cooled by injecting the refrigerant liquid into the discharge space of the compressor.
In order to achieve the above object, a compressor according to the present disclosure includes: a discharge valve; a discharge space formed downstream of the discharge valve; a liquid injection hole for injecting a refrigerant liquid into the discharge space; and a heat medium flow path located opposite to the discharge space across a partition wall forming the discharge space.
Further, a compressor system according to the present disclosure is a compressor system, including: a low-stage compression part; and a high-stage compression part. At least the low-stage compression part is constituted by the compressor as defined in the above.
Herein, the “low-stage compression part” and the “high-stage compression part” include a low-stage compressor and a high-stage compressor each having an independent casing, and a low-stage compressor and a high-stage compressor housed in a single housing casing, for example, a reciprocating compressor.
With the compressor and the compressor system according to the present disclosure, since the above-described heat medium flow path is provided, it is possible to increase the temperature of the compressor casing which includes the partition wall forming the discharge space, making it possible to suppress the occurrence of frost on the surface of the compressor.
Some embodiments of the present invention will be described below with reference to the accompanying drawings. It is intended, however, that unless particularly specified, dimensions, materials, shapes, relative positions and the like of components described or shown in the drawings as the embodiments shall be interpreted as illustrative only and not intended to limit the scope of the present invention.
For instance, an expression of relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “centered”, “concentric” and “coaxial” shall not be construed as indicating only the arrangement in a strict literal sense, but also includes a state where the arrangement is relatively displaced by a tolerance, or by an angle or a distance whereby it is possible to achieve the same function.
For instance, an expression of an equal state such as “same”, “equal”, and “uniform” shall not be construed as indicating only the state in which the feature is strictly equal, but also includes a state in which there is a tolerance or a difference that can still achieve the same function.
Further, for instance, an expression of a shape such as a rectangular shape or a tubular shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved.
On the other hand, an expressions such as “comprising”, “including”, “having”, “containing”, and “constituting” one constitutional element are not intended to be exclusive of other constitutional elements.
Therefore, in order to suppress the occurrence of frost on the casing 18, the compressor 10 includes a heat medium flow path 20 located opposite to the discharge space Sv across a partition wall 18a forming the discharge space Sv. By flowing a heat medium through the heat medium flow path 20, the temperature of the casing 18 including the partition wall 18a is increased, making it possible to suppress the occurrence of frost on the surface of the casing 18.
In an embodiment, the compressor 10 includes a lubricant oil flow path 22 through which lubricant oil r supplied to a part to be lubricated flows. The heat medium flow path 20 is disposed in series or parallel with the lubricant oil flow path 22. According to the present embodiment, since it is possible to cause the lubricant oil r, which has absorbed the heat of the part to be lubricated in the compressor 10 by lubricating and cooling the part to be lubricated, to flow through the heat medium flow path 20, the temperature of the casing 18, which includes the partition wall 18a forming the discharge space Sv, can be increased by potential heat of the lubricant oil r. Therefore, it is possible to suppress the occurrence of frost on the surface of the casing 18 of the compressor 10. The part to be lubricated of the compressor 10 includes, as an example, at least either of a rotor or a rotor support portion. As a more specific example, the parts to be lubricated are a crank shaft 48 and a thrust bearing 50, which will be described later. The part to be lubricated may be either the crank shaft 48 or the thrust bearing 50.
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Furthermore, as another embodiment, for example, heated hot water, an antifreeze liquid, or the like, which is used as a cooling liquid in another part of the compressor 10, may be supplied to the heat medium flow path 20 to heat the discharge space Sv.
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According to the present embodiment, the liquid injection hole 14 can be formed at a position avoiding the head cover 18. If the heat medium flow path 20 needs to be disposed on the head cover 18 side and the liquid injection hole 14 is disposed on the head cover 18 side, the installation positions of the heat medium flow path 20 and the liquid injection hole 14 interfere. In the present embodiment, since the liquid injection hole 14 can be formed at the position on the valve plate 44 side avoiding the head cover 18, it is possible to realize a layout of the liquid injection hole 14 that can avoid the interference with the heat medium flow path 20.
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The refrigerant gas compressed by the cylinder 98 is discharged to a discharge chamber 102 via a discharge valve 100 and discharged from the discharge chamber 102 to the refrigerant circulation path 86. The refrigerant gas discharged to the refrigerant circulation path 86 is sucked into the suction chamber 94 of the high-stage compressor 84 after the lubricant oil is separated by an oil separator 104. The refrigerant gas sucked into the suction chamber 94 of the high-stage compressor 84 is further sucked into the cylinder 98 via the suction valve 96, is compressed, and is discharged from the discharge chamber 102 to the refrigerant circulation path 86. The refrigerant gas discharged to the refrigerant circulation path 86 is cooled and liquefied by the condenser 106 after the lubricant oil is separated by the oil separator 104.
A branch path 108 branching off from the refrigerant circulation path 86 is disposed downstream of the liquid receiver 88, and the branch path 108 is provided with a liquid pump 110 and a pressure regulating valve 112. The branch path 108 is connected to the discharge chamber 102 of the high-stage compressor 84, and the refrigerant liquid is pressurized to have a higher pressure than the discharge chamber 102 of the high-stage compressor 84 by controlling a rotation speed of the oil pump 26 and the pressure control with the pressure regulating valve 112, and is injected into the discharge chamber 102 from an injection nozzle 114 disposed in the discharge chamber 102. The injected refrigerant liquid evaporates under the temperature and pressure conditions of the discharge chamber 102 to cool the discharge space.
Further, the refrigerant circulation path 86 is provided with a branch path 116 branching off from the refrigerant circulation path 86 at a downstream position of the branch path 108. The branch path 116 is connected to the injection nozzle 114 disposed on an inner wall surface of the discharge chamber 102 of the low-stage compressor 82. Since the discharge chamber 102 of the low-stage compressor 82 has the lower pressure than the branch path 116, the refrigerant liquid can be supplied to the discharge chamber 102 at the same pressure without increasing the pressure. The discharge chamber 102 of the low-stage compressor 82 is cooled by evaporation of the refrigerant liquid injected from the injection nozzle 114 under the temperature and pressure conditions of the discharge chamber 102. In the present embodiment, since the low-stage compressor 82 is constituted by the compressor 10 according to each of the above-described embodiments, it is possible to suppress frost generated on the surface of the casing (head cover) 18 of the compressor 10.
In the compressor system 80 shown in
The contents described in the above embodiments would be understood as follows, for instance.
1) A compressor (10) according to one aspect includes: a discharge valve (12); a discharge space (Sv) formed downstream of the discharge valve; a liquid injection hole (14) for injecting a refrigerant liquid into the discharge space; and a heat medium flow path (20) located opposite to the discharge space across a partition wall (18a) forming the discharge space.
With such configuration, since the above-described heat medium flow path is provided, it is possible to increase the temperature of the compressor casing which includes the partition wall forming the discharge space, making it possible to suppress the occurrence of frost on the surface of the compressor.
2) A compressor according to another aspect is the compressor as defined in 1), including: a lubricant oil flow path (22) through which lubricant oil (r) supplied to a part to be lubricated of the compressor flows. The heat medium flow path (20) is disposed in series or parallel with the lubricant oil flow path (22).
With such configuration, since it is possible to cause the lubricant oil, which has been used to lubricate the part to be lubricated of the compressor and absorbed the heat of the part to be lubricated, to flow through the heat medium flow path, the temperature of the partition wall forming the discharge space can be increased by potential heat of the lubricant oil. Therefore, it is possible to suppress the occurrence of frost in the compressor casing including the partition wall.
3) A compressor according to still another aspect is the compressor as defined in 2), wherein the heat medium flow path is arranged in series with the lubricant oil flow path such that a circulation path (24) for the lubricant oil including the part to be lubricated, the lubricant oil flow path (22), and the heat medium flow path is formed, and wherein the compressor comprises an oil pump (26) for circulating the lubricant oil in the circulation path.
With such configuration, since the lubricant oil flowing through the lubricant oil circulation path exchanges heat with the discharge gas in the heat medium flow path and is cooled by the discharge gas, the heat medium flow path doubles as an oil cooler. Therefore, a dedicated oil cooler is not required, making it possible to reduce a cost.
4) A compressor according to yet another aspect is the compressor as defined in any one of 1) to 3), including: a compressor driving motor (54); and a coolant flow path (72) for cooling the compressor driving motor. The coolant flow path communicates with the heat medium flow path (20).
With such configuration, since the coolant for cooling the compressor driving motor flows though the heat medium flow path, the temperature of the compressor casing which includes the partition wall forming the discharge space can be increased by potential heat of the coolant that has cooled the compressor driving motor and absorbed heat, making it possible to suppress the occurrence of frost on the surface of the compressor.
5) A compressor according to yet another aspect is the compressor as defined in any one of 1) to 4), including: a compressor casing (16); a cylinder (40) disposed in the compressor casing; a piston (42) for reciprocating inside the cylinder; a valve plate (44) disposed at one end of the cylinder and configured to support the discharge valve; and a head cover (18) which includes the partition wall (18a) forming the discharge space.
With such configuration, the temperature of the above-described head cover can be increased by the heat medium flowing through the heat medium flow path, making it possible to suppress the occurrence of frost on the surface of the head cover.
6) A compressor according to yet another aspect is the compressor as defined in 5), including: a jacket cover (74) disposed on an outer surface of the head cover and internally having a heat medium introduction space. The heat medium introduction space forms the heat medium flow path (20).
With such configuration, the heat medium flow path can be formed simply by mounting the above-described jacket cover on the existing compressor and the other parts do not need modification, making it possible to easily form the heat medium flow path.
7) A compressor according to yet another aspect is the compressor as defined in 5) or 6), wherein the liquid injection hole (14) includes: a through hole (14a) formed in the valve plate (44); and a communication hole (14b) disposed in a wall portion of the compressor casing (16) and communicating with the through hole (14a) to cause the through hole (14a) to communicate with an external space.
With such configuration, since the heat medium flow path needs to be disposed on the head cover side and the liquid injection hole is formed not on the head cover side but on the valve plate side, it is possible to avoid interference with the heat medium flow path and it is possible to realize the layout of injection hole.
8) A compressor according to yet another aspect is the compressor as defined in any one of 5) to 7), wherein an outer peripheral edge portion of the valve plate (44) is interposed between the compressor casing (16) and an outer peripheral edge portion of the head cover (18).
With such configuration, the outer peripheral edge portions of the compressor casing, the valve plate, and the head cover are fastened together with a fastener such as a bolt, making it easier to install the valve plate. Further, since the end face of the outer peripheral edge portion of the valve plate is exposed to the external space, it is easy to form the liquid injection hole through which the discharge space and the external space communicate with each other.
9) A compressor system (80) according to one aspect is a compressor system (80), including: a low-stage compression part (82); and a high-stage compression part (84). At least the low-stage compression part (82) is constituted by the compressor (10) as defined in any one of 5) to 8).
With such configuration, since the low-stage compression part is constituted by the compressor according to each embodiment, it is possible to suppress the occurrence of frost on the surface of the compressor in the low-stage compression part.
18
a Partition wall (partition wall forming discharge space)
20 Heat medium flow path
22 Lubricant oil flow path
24 Circulation path
26 Oil pump
28 Oil cooler
30, 108, 116 Branch path
32, 34 Flow control valve
40, 98 Cylinder
42 Piston
44 Valve plate
46 Crankcase
48 Crank shaft
50 Thrust bearing
52 Connecting rod
53 Crank pin
54 Compressor driving motor
56 Oil filter
58 Pressure regulating valve
60, 62 Oil passage
63, 96 Suction valve
64 Coil spring
66 Valve cage
68, 78 Bolt
70 Valve plate
72 Coolant flow path
74 Jacket cover
74
a Inlet hole
74
b Outlet hole
76 Refrigerant path
80 Compressor system
82 Low-stage compressor
84 High-stage compressor
86 Refrigerant circulation path
88 Liquid receiver
90 Expansion valve
92 Evaporator
94 Suction chamber
102 Discharge chamber
104 Oil separator
106 Condenser
110 Liquid pump
112 Pressure regulating valve
114 Injection nozzle
Gv Discharge gas
Os Oil reservoir
Si Suction space
Sv Discharge space
r Lubricant oil
Number | Date | Country | Kind |
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2020-148523 | Sep 2020 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/031462 | 8/27/2021 | WO |