Methods for reducing the friction of a refrigerant compressor, as well as refrigerant compressors for a machine or system

Abstract

The invention relates to a method for reducing friction during the start-up of a refrigerant compressor (2), in particular a thermal machine (1) or a thermal system (1) for household, transport or industry, wherein the refrigerant compressor (2) has a compression piston (20) that is linearly movable back and forth in a compressor cylinder (10) for drawing in, compressing and expelling a refrigerant (5), and the compression piston (20) is mounted in the compressor cylinder (10) by means of a gas pressure sliding guide (30), characterized in that the gas pressure sliding guide (30) is supplied with pressurized refrigerant (5) essentially immediately before the start-up of the refrigerant compressor (2).

Description

[0001] The invention relates to a method for reducing friction during the start-up of a refrigerant compressor, particularly of a thermal machine or thermal system. The invention further relates to a refrigerant compressor for a thermal machine or thermal system. It also relates to a machine and a system. State of the art

[0002] A compressor is used to compress a fluid such as air, a refrigerant, or another gas (mixture), whereby the compressor receives energy from an energy source such as an electric motor or a turbine. A compressor, in particular a (reciprocating) piston compressor, is frequently used in households, transportation, or industry, e.g., in a machine, especially a thermal machine, preferably a fluid machine, an air conditioner, a refrigerator, a heat pump, or in a system, especially a thermal system, preferably an air conditioning system and / or a heat pump system, etc.

[0003] In a piston compressor, the compression piston is linearly reciprocated within a compressor cylinder by means of, for example, an electric linear motor inside a hermetically sealed housing. This movement draws in, compresses, and expels the fluid. In a conventional refrigerant compressor, the compression piston is supported, for example, by a hydrostatic or aerostatic sliding bearing. In an aerostatic application—referred to here as a gas-pressure sliding bearing—a small proportion of compressed refrigerant is used to supply the bearing to the gas-pressure sliding bearing. Task

[0004] Increasing the gas pressure of a refrigerant in a thermal machine or thermal system by a refrigerant compressor occurs during the compression movement of the compression piston, which also applies to its gas pressure sliding guide. This means that when the refrigerant compressor is (re)started (after a sufficiently long period), no gas pressure is available for the sliding guide of the compression piston in a compressor cylinder, resulting in solid friction, particle generation, and comparatively high friction losses. It is an object of the invention to provide an improved refrigerant compressor. Disclosure of the invention

[0005] The object of the invention is achieved by a method for reducing the friction of a refrigerant compressor, preferably of a thermal machine or a thermal system for household, transport, or industry; by means of a refrigerant compressor for a thermal machine or a thermal system for household, transport, or industry; and by means of a machine, in particular a thermal machine, preferably a fluid machine, an air conditioner, a refrigerator, a heat pump, or a system, in particular a thermal system, preferably an air conditioning system and / or a heat pump system. Advantageous embodiments, additional features, and / or advantages of the invention will become apparent from the dependent claims and the following description.

[0006] For the method according to the invention, the refrigerant compressor has a compression piston that is linearly movable back and forth within a compressor cylinder for drawing in, compressing, and expelling a refrigerant, wherein the compression piston is mounted in the compressor cylinder by means of a gas-pressure sliding guide. According to the invention, the gas-pressure sliding guide is supplied with pressurized refrigerant essentially immediately before the refrigerant compressor is started. Starting also includes restarting (re-running) the refrigerant compressor, whereby the compression piston of the refrigerant compressor begins to move and subsequently moves back and forth.

[0007] This allows the gas pressure guide, i.e., the gas pressure bearings of the compression piston, to be pressurized even before the refrigerant compressor starts. This avoids solid friction and eliminates the need for special friction-reducing coatings, thus improving the efficiency and wear behavior of the refrigerant compressor.

[0008] After a sufficiently long period of standstill of the refrigerant compressor, the gas pressure slide guide, which is comparatively low-pressure or virtually pressureless compared to the operating pressure, can be supplied with printed refrigerant. The gas pressure slide guide can be supplied with printed refrigerant before the refrigerant compressor is started: from a refrigerant pressure accumulator of the refrigerant compressor, machine, or system; through a slide guide supply valve belonging to the refrigerant pressure accumulator; and / or through a slide guide refrigerant supply of the refrigerant compressor.

[0009] The refrigerant pressure accumulator can be supplied with pressurized refrigerant during operation of the refrigerant compressor. The pressurized refrigerant can flow into the refrigerant pressure accumulator via: the sliding guide refrigerant supply; an inlet restrictor located upstream in the sliding guide refrigerant supply; the sliding guide supply valve belonging to the refrigerant pressure accumulator; and / or gas pressure bearings in the compressor cylinder leading into the gas pressure sliding guide.

[0010] The friction reduction method can essentially be carried out every time the refrigerant compressor is started. Furthermore, the friction reduction method according to the invention can be carried out on or by a refrigerant compressor according to the invention.

[0011] The refrigerant compressor according to the invention comprises a compression piston that is linearly movable back and forth within a compressor cylinder for drawing in, compressing, and expelling a refrigerant, wherein the compression piston is mounted in the compressor cylinder by means of a gas-pressure sliding guide. According to the invention, the refrigerant compressor has a refrigerant pressure accumulator by means of which the gas-pressure sliding guide can be supplied with pressurized refrigerant. That is, the refrigerant pressure accumulator is provided, and in particular arranged, on / in the refrigerant compressor and not on / in the machine or system. Furthermore, the refrigerant in the refrigerant pressure accumulator is preferably gaseous. The gas-pressure sliding guide is also preferably designed as a radial bearing.

[0012] The refrigerant pressure accumulator can be fluid-mechanically connected to a sliding-guide refrigerant supply of the refrigerant compressor. The refrigerant pressure accumulator can be fluid-mechanically connected to the sliding-guide refrigerant supply via a preferably single pressure accumulator line. That is, the sliding-guide refrigerant supply is designed such that the refrigerant pressure accumulator can preferably be filled and emptied through a single fluid line, i.e., the pressure accumulator line. A sliding-guide supply valve, preferably a solenoid valve, can be installed on / in the pressure accumulator line or on / in the refrigerant pressure accumulator. That is, the sliding-guide supply valve is installed upstream of the refrigerant pressure accumulator in the refrigerant compressor.

[0013] Upstream of the refrigerant pressure accumulator (i.e., downstream during emptying and upstream during filling), a sliding guide supply valve can be installed in the sliding guide refrigerant supply system. This valve allows the gas-pressure sliding guide to be supplied with pressurized refrigerant from the refrigerant pressure accumulator. After a sufficiently long period of standstill of the refrigerant compressor and before it is started, the sliding guide supply valve can be opened, thus supplying a gas-pressure sliding guide, which is at a relatively low or virtually no pressure compared to the operating pressure, with pressurized refrigerant.

[0014] Due to the compression stroke of the compression piston and with the sliding guide supply valve in an open position, the refrigerant pressure accumulator can be filled with pressurized refrigerant. With the sliding guide supply valve closed, the refrigerant pressure accumulator is, of course, fluidly separated from the sliding guide refrigerant supply. Before the compression piston starts moving (see above), the sliding guide supply valve can be opened, allowing the gas-pressurized sliding guide to be supplied with pressurized refrigerant. Furthermore, the refrigerant pressure accumulator can be filled with pressurized refrigerant via the sliding guide refrigerant supply, and / or the gas-pressurized sliding guide can be supplied with pressurized refrigerant from the refrigerant pressure accumulator.

[0015] The refrigerant supply for the sliding guide can be fluid-mechanically connected to the compression chamber downstream of the compression cylinder. In this configuration, the refrigerant supply can branch off fluid-mechanically from a downstream refrigerant line of the refrigerant compressor, which terminates at / in the compression chamber. Such a downstream refrigerant line leads, for example, to a condenser. Furthermore, an inlet restrictor can be installed on / in the refrigerant supply upstream of the gas pressure bearings of the gas pressure sliding guide. Additionally, the refrigerant supply for the sliding guide can supply refrigerant to multiple or numerous gas pressure bearings of the gas pressure sliding guide.

[0016] The sliding guide refrigerant supply can have at least one sliding guide supply line leading to the gas pressure bearings located in the compressor cylinder. The downstream refrigerant line can have a return check valve upstream of the inlet restrictor, by means of which backflow of refrigerant into the compression chamber can be prevented. The return check valve of the sliding guide refrigerant supply can be located upstream or downstream of the inlet restrictor. Furthermore, a method according to the invention for reducing friction during the start-up of a refrigerant compressor can be implemented or carried out by the refrigerant compressor.

[0017] An upstream refrigerant line can open into / in the compression chamber, which is in fluid communication with a refrigerant reservoir. Such an upstream refrigerant line originates, for example, from an evaporator. The upstream refrigerant line can have an inlet check valve by means of which backflow of refrigerant into the refrigerant reservoir can be prevented. - The machine or system according to the invention comprises a refrigerant circuit, wherein a method according to the invention for reducing friction during the start-up of a refrigerant compressor can be carried out or is carried out by the machine or system, and / or the machine or system has a refrigerant compressor according to the invention. Brief description of the character

[0018] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying schematic drawing, which is not to scale. In the invention, a feature can be positive (i.e., present) or negative (i.e., absent). In this specification, a negative feature is not explicitly defined as a feature unless the invention specifically emphasizes its absence. That is, the actual invention, rather than one constructed by the prior art, consists of omitting this feature. The absence of a feature (negative feature) in an exemplary embodiment indicates that the feature may be optional (to a person skilled in the art).

[0019] The purely exemplary and highly schematic figure (Fig.) of the drawing shows, in a kind of two-dimensional sectional view in combination with a hydraulic circuit diagram, a refrigerant compressor according to the invention with a gas pressure sliding guide, which can be supplied with printed refrigerant from a refrigerant pressure accumulator immediately before and possibly also when the refrigerant compressor is started. Embodiments of the invention

[0020] The invention – a method for reducing friction during the start-up of a refrigerant compressor 2, and a refrigerant compressor 2 – is explained in more detail below with reference to exemplary embodiments of an embodiment shown in the figure. The refrigerant compressor 2 can be used in a thermal machine 1, preferably a fluid machine 1, an air conditioner 1, a refrigerator 1, a heat pump, etc.; or in a system 1, in particular a thermal system 1, preferably an air conditioning system and / or a heat pump system 1, etc.; for household, transportation, and / or industrial applications, etc. In principle, the invention is applicable to a refrigerant compressor 2 with a gas pressure sliding guide 30 for its compression piston 20.

[0021] The drawing shows only those sections of the refrigerant compressor 2 and the machine 1 or system 1 that are necessary for understanding the invention. Although the invention is described and illustrated in detail by preferred embodiments, the invention is not limited by the disclosed embodiments. Other variations can be derived from them without departing from the scope of protection of the invention.

[0022] The figure shows a section of a refrigerant circuit 4 of machine 1 or system 1, wherein an upstream refrigerant line 6 leads into (terminates in) a compression chamber 22 of the refrigerant compressor 2, and a downstream refrigerant line 7 leads away from (terminates in) the compression chamber 22 of the refrigerant compressor 2. The upstream refrigerant line 6 and the downstream refrigerant line 7 are in intermittent fluid contact (check valves 62, 72; see below) across the compression chamber 22.

[0023] In the compression chamber 22, a refrigerant 5 from the machine 1 or the system 1 can be compressed. This refrigerant can be drawn into the compression chamber 22 from the upstream refrigerant line 6 and discharged from the compression chamber 22 into the downstream refrigerant line 7. The upstream refrigerant line 6 has an inlet valve 62, preferably designed as an inlet check valve 62, and the downstream refrigerant line 7 has an outlet valve 72, preferably designed as an outlet check valve 72. The inlet valve 62 prevents refrigerant 5 from flowing back into the upstream refrigerant line 6 and into a refrigerant reservoir during compression and discharge. And by means of the outflow valve 72, a backflow of refrigerant 5 from the downstream refrigerant line 7 into the compression chamber 22 can be prevented.

[0024] The refrigerant compressor 2 has a compressor cylinder 10 that is fixed to the compressor and a compression piston 20 that is linearly movable back and forth (dual case) within it, i.e., movable relative to the refrigerant compressor 2, for drawing in, compressing, and expelling the refrigerant 5. The compression piston 20 is mounted in the compressor cylinder 10 by means of a gas-pressure sliding guide 30. Between an upper free end of the compression piston 20 and the compressor cylinder 10, the compression chamber 22 is arranged, the volume of which can be varied by the movable compression piston 20.

[0025] The gas pressure slide 30 can be supplied with printed refrigerant 5 by a plurality or multiple gas pressure bearings 12 in the compressor cylinder 10. During supply, printed refrigerant 5 flows through the gas pressure bearings 12 into the gas pressure slide 30 between the compressor cylinder 10 and the compression piston 20. Each gas pressure bearing 12 can be supplied with refrigerant 5, for example, from a bearing supply line 44. Of course, an alternative, such as a bearing supply room or multiple bearing supply rooms instead of bearing supply lines 44, is also possible.

[0026] The storage supply lines 44, or their alternative, can be supplied with refrigerant 5 by at least one sliding supply line 41. The sliding supply line 41 branches off downstream (preferably) or upstream of the discharge valve 72 from the downstream refrigerant line 7 and leads to the storage supply lines 44. Preferably, an inlet restrictor 42 is installed in the sliding supply line 41 after the branch point from the downstream refrigerant line 7, or the inlet restrictor 42 forms the branch point of the sliding supply line 41 from the downstream refrigerant line 7.

[0027] The sliding guide supply line 41, the inlet throttle 42, the bearing supply lines 44 or their alternative, and the gas pressure bearings 12 form a sliding guide refrigerant supply 40 for the refrigerant compressor 2. Furthermore, in one embodiment of the invention, a pressure accumulator line 48 can open into the sliding guide supply line 41. An alternative is, for example, an indirect or a direct fluid-mechanical connection of the pressure accumulator line 48 to the gas pressure sliding guide 30.

[0028] The pressure accumulator line 48 is in fluid communication with a refrigerant pressure accumulator 46 via a sliding guide supply valve 47, wherein the refrigerant pressure accumulator 46 is preferably a component of the refrigerant compressor 2. If the sliding guide supply valve 47 is closed, the fluid connection between the refrigerant pressure accumulator 46 and the sliding guide supply line 41 is interrupted, and if the sliding guide supply valve 47 is open, the fluid connection between the refrigerant pressure accumulator 46 and the sliding guide supply line 41 is established.

[0029] The sliding guide supply valve 47 is specifically designed as a solenoid valve 47, but can also be of other design. The refrigerant pressure accumulator 46, the sliding guide supply valve 47, and the pressure accumulator line 48 can be considered part of the sliding guide refrigerant supply 40. With the sliding guide supply valve 47 closed, the refrigerant pressure accumulator 46 contains pressurized refrigerant 5 before the refrigerant compressor 2 is started (see above).

[0030] Now, essentially immediately before the start of the refrigerant compressor 2, the sliding guide supply valve 47 can be opened, and the gas pressure sliding guide 30, which is under low fluid pressure or even essentially under ambient pressure, can be supplied with printed refrigerant 5, so that the compression piston 20 in the compression cylinder 10 generates only fluid friction and no solid friction when the refrigerant compressor 2 is started.

[0031] That is, essentially immediately after pressure builds up in the gas pressure slide 30 by means of the printed refrigerant 5 from the refrigerant pressure accumulator 46, the refrigerant compressor 2 starts. Subsequently, the slide supply valve 47 can remain open or be closed. The partially or completely emptied refrigerant pressure accumulator 46 can be refilled with printed refrigerant 5 by the operating refrigerant compressor 2. Once this has occurred, the slide supply valve 47 closes.

Claims

[1] Method for reducing friction during the start-up of a refrigerant compressor (2), in particular a thermal machine (1) or a thermal system (1) for household, transport or industry, wherein the refrigerant compressor (2) has a compression piston (20) that is linearly movable back and forth in a compressor cylinder (10) for drawing in, compressing and expelling a refrigerant (5), and the compression piston (20) is mounted in the compressor cylinder (10) by means of a gas pressure sliding guide (30), characterized by , that the gas pressure sliding guide (30) is supplied with printed refrigerant (5) essentially immediately before the start of the refrigerant compressor (2). [2] Method for reducing friction according to the preceding claim, characterized by, that after a sufficiently long period of standstill of the refrigerant compressor (2) the gas pressure sliding guide (30) which is comparatively low pressure or comparatively pressureless compared to an operating pressure is supplied with printed refrigerant (5). [3] Method for reducing friction according to any one of the preceding claims, characterized by , that the gas pressure sliding guide (30) before starting the refrigerant compressor (2): • from a refrigerant pressure accumulator (46) of the refrigerant compressor (2), the machine (1) or the system (1), • through a sliding guide supply valve (47) belonging to the refrigerant pressure accumulator (46), and / or • is supplied with printed refrigerant (5) by a sliding guide refrigerant supply (40) of the refrigerant compressor (2). [4] Method for reducing friction according to any one of the preceding claims, characterized by, that the refrigerant pressure accumulator (46) is supplied with printed refrigerant (5) during operation of the refrigerant compressor (2), preferably the printed refrigerant (5): • through the sliding guide refrigerant supply (40) into the refrigerant pressure storage tank (46), • flows in through an inlet throttle (42) installed upstream in the sliding guide refrigerant supply (40), • flows through the sliding guide supply valve (47) belonging to the refrigerant pressure accumulator (46), and / or • furthermore, flows via gas pressure bearings (12) in the compressor cylinder (10) into the gas pressure sliding guide (30). [5] Method for reducing friction according to any one of the preceding claims, characterized by, that the friction reduction method is essentially carried out at each start of the refrigerant compressor (2), and / or the friction reduction method is feasible and / or is carried out in or by a refrigerant compressor (2) which is designed according to one of the following claims. [6] Refrigerant compressor (2) for a thermal machine (1) or a thermal system (1) for household, transport or industrial use, with a compression piston (20) which is linearly movable back and forth in a compressor cylinder (10) for drawing in, compressing and expelling a refrigerant (5), wherein the compression piston (20) is mounted in the compressor cylinder (10) by means of a gas pressure sliding guide (30), characterized by , that the refrigerant compressor (2) has a refrigerant pressure accumulator (46) by means of which the gas pressure sliding guide (30) can be supplied with printed refrigerant (5). [7] Refrigerant compressor (2) according to the preceding claim, characterized by , that: • the refrigerant pressure accumulator (46) is fluid-mechanically connected to a sliding guide refrigerant supply (40) of the refrigerant compressor (2), • the refrigerant pressure accumulator (46) is fluid-mechanically connected to the sliding guide refrigerant supply (40) via a preferably single pressure accumulator line (48), and / or • a sliding guide supply valve (47) is provided on / in the pressure storage line (48) or on / in the refrigerant pressure storage tank (46), which is designed in particular as a solenoid valve (47). [8] Refrigerant compressor (2) according to any one of the preceding claims, characterized by, that a sliding guide supply valve (47) is installed in the sliding guide refrigerant supply (40) upstream of the refrigerant pressure storage tank (46), through which the gas pressure sliding guide (30) can be supplied with printed refrigerant (5) from the refrigerant pressure storage tank (46), wherein, in particular, after a sufficiently long period of standstill of the refrigerant compressor (2) and before its start, the sliding guide supply valve (47) can be opened and thus a gas pressure sliding guide (30) that is comparatively low in pressure or comparatively pressureless compared to an operating pressure can be supplied with printed refrigerant (5). [9] Refrigerant compressor (2) according to any one of the preceding claims, characterized by , that: • due to a compression stroke of the compression piston (20) and in an open position of the sliding guide supply valve (47), the refrigerant pressure accumulator (46) can be filled with printed refrigerant (5), • before a start movement of the compression piston (20) the sliding guide supply valve (47) can be opened and thus the gas pressure sliding guide (30) can be supplied with printed refrigerant (5), and / or • the refrigerant pressure storage tank (46) can be filled with printed refrigerant (5) via the sliding guide refrigerant supply (40) and / or the gas pressure sliding guide (30) can be supplied with printed refrigerant (5) from the refrigerant pressure storage tank (46). [10] Refrigerant compressor (2) according to any one of the preceding claims, characterized by , that the sliding guide refrigerant supply (40) is fluid-mechanically connected to the compression chamber (22) downstream of a compression chamber (22) of the compression cylinder (10), wherein: • the sliding guide refrigerant supply (40) branches off fluid-mechanically from a downstream refrigerant line (7) of the refrigerant compressor (2), which opens at / in the compression chamber (22), • an inlet throttle (42) is installed on / in the sliding guide refrigerant supply (40) upstream of the gas pressure bearings (12) of the gas pressure sliding guide (30), and / or • a plurality or a multitude of gas pressure bearings (12) of the gas pressure sliding guide (30) can be supplied with refrigerant (5) by means of the sliding guide refrigerant supply (40). [11] Machine (1), in particular thermal machine (1), preferably fluid machine, air conditioner, refrigerator, heat pump, or system (1), in particular thermal system (1), preferably air conditioner and / or heat pump system, comprising a refrigerant circuit (4), characterized by , that the machine (1) or the system (1) can implement or implement a method for reducing friction during the start-up of a refrigerant compressor (2) according to one of the preceding claims, and / or the machine (1) or the system (1) comprises a refrigerant compressor (2) according to one of the preceding claims.

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