COMPRESSOR UNIT AND METHOD FOR OPERATING A COMPRESSOR UNIT

Description

[0001] The invention relates to a compressor unit comprising a screw compressor with a compressor housing, a screw rotor chamber arranged in the compressor housing, at least one screw rotor arranged in the screw rotor chamber and rotatably mounted on the compressor housing about a screw rotor axis, which receives gaseous medium supplied via a low-pressure chamber arranged in the compressor housing with an initial volume and discharges it compressed to a final volume in the area of ​​a high-pressure chamber arranged in the compressor housing, and at least one control slide arranged in a slide channel of the compressor housing and adjacent to the screw rotor, which is movable in a displacement direction parallel to the screw rotor axis and is designed to influence the final volume and / or the initial volume.

[0002] Such compressor units are known from the prior art, as from US 4 609 329 A and EP 1 498 611 A1, whereby compressor units with screw compressors require considerable know-how in their use due to the complexity of the functional relationships in these screw compressors.

[0003] The invention is therefore based on the objective of improving a compressor unit of the type described above in such a way that it can be used with as little functional know-how as possible regarding the functional relationships of the screw compressor.

[0004] This problem is solved according to the invention in a compressor unit of the type described above by the features of claim 1. Furthermore, the problem is also solved by a method according to claim 15.

[0005] The advantage of the solution according to the invention is therefore that the compressor operating control unit makes it possible to perform compressor operating functions that support the operation of the compressor, i.e., to take over individual functions that are important for the operation of the compressor, so that the compressor unit can be used in a plant with less external effort.

[0006] In particular, such compressor units are intended for compressing refrigerants in refrigeration circuits of refrigeration systems, with such refrigeration systems typically being equipped with a complex control system.

[0007] The present solution according to the invention thus simplifies and / or facilitates the installation of such refrigeration systems, since the refrigeration system manufacturer is no longer forced to implement all the complex functional relationships for such a compressor unit in the system control system if the compressor unit already implements such functional relationships by means of the compressor operating control unit. This means that a refrigeration system manufacturer, in particular, can reduce the refrigeration system control system to transmitting one or more request signals for the operation of the compressor unit to the compressor operating function unit, and these request signals are then implemented by the compressor operating control unit according to the compressor operating functions to be implemented.

[0008] The solution according to the invention additionally provides that the compressor operating function is an operating condition monitoring function and that, in particular, for the execution of the operating condition monitoring function, the execution of at least one parameter acquisition function and at least one protection function is recorded.

[0009] Such a recording of the compressor operating functions makes it possible to monitor the operating states of the compressor unit according to the invention throughout its entire operation and to detect short-term exceedances of the respective permissible operating states or to identify exceedances of the respective limits in an operating diagram.

[0010] Furthermore, the operating condition monitoring function has the advantage that, in the event of malfunctions, there is a simple way to determine the cause of the malfunction based on the recorded compressor operating functions.

[0011] According to the invention, it is further provided that the recording of the at least one functional parameter and / or the execution of at least one protective function and / or the execution of the at least one control function is carried out over time, so that a time-resolved analysis of the operating states in the past is possible, which facilitates troubleshooting in particular in the case of malfunctions.

[0012] Regarding the compressor operation function to be taken over by the compressor operation control unit, a wide variety of possibilities are conceivable.

[0013] An advantageous solution provides that the at least one compressor operating function is a parameter acquisition function and that, in particular, for the execution of the parameter acquisition function, at least one of the following function parameters is acquired: pressure of the medium on the inlet side of the screw compressor, temperature of the medium on the inlet side of the screw compressor, pressure of the medium on the outlet side of the screw compressor, temperature of the medium on the outlet side of the screw compressor, position of the at least one control valve, position of all control valves, lubricant temperature, lubricant flow, lubricant differential pressure at the lubricant filter, lubricant level in at least one lubricant inlet, speed of the drive motor, phase position of the drive motor, temperature of the drive motor, voltage at the drive motor, current consumption of the drive motor.

[0014] The advantage of this solution is that by recording at least one or more of these functional parameters, it is possible to obtain sufficient information about the respective operating state of the screw compressor, so that the complex functional relationships of a screw compressor can be easily understood.

[0015] It is particularly advantageous if another compressor operating function is a protective function, if at least one parameter acquisition function is performed to execute the protective function, and if the at least one function parameter is compared with at least one reference parameter, and if a warning message and / or a shutdown of the screw compressor occurs if the at least one reference parameter is exceeded or fallen below.

[0016] Such a protective function has the advantage that it allows the compressor unit to operate safely without the need for external units or external functional modules, for example in the plant control system, to ensure the safe operation of the screw compressor.

[0017] In particular, with such a protective function, all essential functional parameters for the respective operating states can be checked and compared with reference parameters.

[0018] For example, it is conceivable to compare parameters such as pressure and / or temperature of the medium on the inlet side as well as pressure and / or temperature of the medium on the outlet side with an operating diagram for the screw compressor, whereby the operating limits of the operating diagram simultaneously represent reference values ​​for pressure and / or temperature on the inlet side and the outlet side, so that, for example, it can be ensured that the screw compressor is operated within its operating limits.

[0019] Furthermore, as part of the protective function, it is conceivable, for example, to record the lubricant temperature and, in particular, to compare it with an upper and a lower reference value in order to ensure adequate lubrication.

[0020] Furthermore, it is conceivable, for example, within the framework of the solution according to the invention, to detect the lubricant level in at least one lubricant inlet and to switch off the screw compressor in the event of a lack of lubricant in at least one lubricant inlet in order to avoid damage to it.

[0021] Finally, as part of a protective function, it is also provided, for example, to monitor the temperature of the drive motor in order to prevent damage to it.

[0022] The same applies, for example, to the voltage and current consumption of the drive motor.

[0023] Furthermore, another advantageous embodiment of the compressor unit according to the invention provides that the at least one compressor operating function is a control function and that, in particular, at least one of the units such as a control valve drive for the control valves, a motor control, a lubricant cooling system, and an injection element for compressed medium for additional cooling is controlled to execute the control function.

[0024] The advantage of such a compressor operating function designed as a control function is that the compressor operating control unit is able, for example on the basis of one or more specifications, to operate the screw compressor in the intended operating state, in particular by controlling the control valves to adjust the volume ratio and compressor output corresponding to the operating state.

[0025] Furthermore, it is also advantageous, for example, if a motor control can be controlled, in order to be able to specify the speed of the screw rotors in particular.

[0026] In principle, the control function could be independent of the request signals and / or function parameters, for example, simply according to one or more specifications.

[0027] However, a particularly advantageous solution is provided if the at least one compressor operating function is an operating state specification function, in which a control function is executed on the basis of at least one request signal and / or at least one function parameter.

[0028] In order to be able to communicate with the compressor operating control unit in a simple manner, it is preferably provided that the compressor operating control unit is equipped with a communication unit for exchanging data with external devices.

[0029] Such an exchange of data with external devices would, for example, be an exchange of data with a plant control system or an exchange of data with a visualization and / or operating unit, which opens up the possibility of monitoring the individual functions of the compressor operating control unit and / or analyzing the operating states of the screw compressor.

[0030] Preferably, the communication unit is designed to exchange data via wired and / or wireless connections, thus simplifying data communication with the compressor control unit. In particular, it is advantageous if the compressor control unit is equipped with a visualization unit that displays at least one operating state of at least one compressor function or its result, enabling simple monitoring of the compressor functions.

[0031] The solution according to the invention provides that the screw compressor has a control housing in which the compressor operating control unit is arranged.

[0032] This solution has the major advantage that it makes it possible to connect the compressor operating control unit with the sensors or units for recording the functional parameters as well as with the units intended for the control function by the manufacturer, so that when the compressor unit is used, such connections are already implemented by the manufacturer and, for example, only communication with the compressor operating control unit needs to be established.

[0033] According to the invention, the control housing is arranged on the compressor housing.

[0034] No further details regarding the design of the screw compressor have been provided above.

[0035] In particular, a screw compressor comprises a compressor housing with a screw rotor chamber arranged therein, two screw rotors arranged in the screw rotor chamber and each rotatably mounted on the compressor housing about a screw rotor axis, the screw contours interlocking and each cooperating with adjacent and partially enclosing compression wall surfaces, in order to receive gaseous medium supplied via a low-pressure chamber arranged in the compressor housing and discharge it in the area of ​​a high-pressure chamber arranged in the compressor housing, wherein the gaseous medium is enclosed at low pressure with an initial volume in compression chambers formed between the screw contours and compression wall surfaces adjacent to them and compressed to a final volume at high pressure.and at least one control valve arranged in a slide channel of the compressor housing and adjacent to both screw rotors with slide compression wall surfaces, which is movable in a displacement direction parallel to the screw rotor axes and is designed to influence the final volume and / or the initial volume.

[0036] In particular, it is advantageously provided that, in order to detect the exact position of the at least one control valve, the screw compressor is designed such that a position detection device is provided for the at least one control valve, that the position detection device has a position indicator element coupled to the at least one control valve, that the at least one position indicator element interacts with a detector element that extends parallel to the displacement direction of the control valve and along which the position indicator element is movable when the at least one control valve is moved, and that the detector element is coupled with an evaluation device that detects the respective position of the position indicator element along the detector element.

[0037] The advantage of this solution lies particularly in the fact that, despite its simple design, it allows for very precise positioning of the control valves.

[0038] In particular, a screw compressor having two control valves, wherein a first control valve is designed to influence at least the final volume and a second control valve is designed to influence at least the initial volume, is provided with a position detection device for the two control valves, comprising a first position indicator element coupled to the first control valve and a second position indicator element coupled to the second control valve, both position indicator elements interacting with a common detector element extending parallel to the direction of movement of the control valves and along which the position indicator elements are movable when the control valves are moved, and the detector element being coupled with an evaluation device that detects the respective positions of the first position indicator element and the second position indicator element along the detector element.

[0039] This solution has the great advantage that it makes it possible to accurately and, in particular, simultaneously detect the positions of two control slides, especially with a single detector element.

[0040] No further details have yet been provided regarding the arrangement of the detector element.

[0041] One advantageous solution provides that the detector element is arranged in a detector channel running parallel to the direction of movement within the compressor housing, so that the detector element is optimally protected from external influences by the detector channel within the compressor housing.

[0042] It is particularly advantageous if the detector channel is closed by a cover, so that easy access to the detector channel is possible via the cover.

[0043] No further details have been provided regarding the design of the detector channel.

[0044] One advantageous solution provides that the detector channel is formed by a groove-like recess in a housing base body, which the cover overlaps.

[0045] Another advantageous solution provides that the lid itself has a groove-like recess that contributes to the detector channel.

[0046] To make it easy to mount the detector element with the lid, an advantageous solution provides that the detector element runs inside the recess of the lid, so that the detector element together with the lid can be removed and, if necessary, replaced.

[0047] Furthermore, it is preferably provided that the at least one position indicator element is arranged in the detector channel and is movable in the direction of displacement.

[0048] No further details have yet been provided regarding the coupling of the at least one position indicator element with the at least one control slide.

[0049] Theoretically, the coupling between the position indicator element and the control slide could be contactless.

[0050] However, for reliable position indication of the at least one control valve, it is advantageous if the at least one position indicator element is mechanically coupled to the respective control valve via a connecting body, and thus the position indicator element is rigidly guided with the respective control valve.

[0051] To establish the connection between the respective position indicator element movable in the detector channel and the control slide, it is preferably provided that the respective connecting body extends through an elongated passage between the detector channel and a slide channel accommodating the at least one control slide.

[0052] It is particularly advantageous if the respective connecting body and the passage together guide the respective control slide in a rotationally fixed manner in the direction of movement, so that a rotationally fixed guidance of the control slides can be achieved simultaneously without the need for a separate guide by a groove in the control slide and a T-nut in the compressor housing.

[0053] The interaction between the at least one position indicator element and the detector element has not yet been specified in more detail.

[0054] One particularly advantageous solution provides that the respective position indicator element interacts with the detector element without contact, so that the position detection of the position indicator elements can be carried out without wear.

[0055] Preferably, the detector element is made of a magnetostrictive material and the position indicator element generates a local magnetic flux through the detector element at its location, which can then be detected via the evaluation circuit in the detector element.

[0056] A particularly cost-effective solution involves a compressor operation control unit, which controls a control valve drive for the respective control valve and detects a movement of the respective control valve using the position detection unit.

[0057] This enables the compressor operating control unit not only to move the respective control valve with the control valve drive, but also to precisely track the movement performed.

[0058] This is particularly advantageous if the control valve drive is implemented as a cylinder arrangement that can be actuated by a medium.

[0059] The compressor operating control unit can be used particularly advantageously when it positions the respective control slide in a position-controlled manner.

[0060] This means that the compressor operating control unit can, on the one hand, control the control valve drive and, on the other hand, detect the position of the respective control valve to determine whether the desired position has been reached or not, and can then precisely approach and, for example, permanently maintain this position by further controlling the control valve drive accordingly.

[0061] This makes it possible to specify individual positions of the respective control valve or, if necessary, several control valves using a compressor control program for the compressor operating control unit, and then to approach and hold these positions with position control using the compressor operating control unit, so that any intermediate positions between the extreme positions are possible in order to operate the screw compressor optimally.

[0062] In particular, it is advantageous if the compressor operating control unit determines the positions of the at least one control valve taking into account at least one or more of the following parameters: pressure level on the inlet side, especially at low pressure; pressure level on the outlet side, especially at high pressure; temperature of the gaseous medium on the inlet side, especially at low pressure; temperature of the gaseous medium on the outlet side, especially at high pressure; rotational speed of the screw rotors; power consumption of a drive motor; parameters of the gaseous medium, especially of the refrigerant; and operating limits of the screw compressor.

[0063] No further details have yet been provided regarding the arrangement of the two control valves relative to each other.

[0064] It is advantageously provided that the first control valve and the second control valve are arranged one behind the other in the direction of their displacement.

[0065] In the case of two control valves arranged one behind the other, it is particularly provided that the first control valve and the second control valve have an identical outer contour.

[0066] Preferably, two control slides positioned one behind the other can be used in such a way that the first control slide and the second control slide can be positioned directly adjacent to each other in a combined position and can be moved together in the direction of displacement.

[0067] Alternatively, with two control valves positioned one behind the other, it is possible for the first and second control valves to be positioned at a distance from each other in a separating position, forming a gap.

[0068] As an alternative to providing two control valves arranged one behind the other, another advantageous solution provides that the first control valve has valve compression wall surfaces directly adjacent to each other, one of which faces one of the screw rotors, and that the second control valve has compression wall surface areas arranged at a distance from each other, one of which borders one of the screw rotors and between which the valve compression wall surfaces of the first control valve are located.

[0069] With such an arrangement of two control valves, it is possible to preferably influence the final volume with the first control valve and to influence the initial volume with the second control valve via the valve compression wall surfaces arranged at a distance from each other.

[0070] Preferably, the first control valve is mounted on the second control valve.

[0071] Preferably, the first control valve is mounted in a valve channel of the second control valve.

[0072] Furthermore, it is preferably provided that the valve compression wall surfaces of the first control valve and the valve compression wall surfaces of the second control valve connect to each other.

[0073] In particular, in the case of the two control valves arranged one behind the other, it is provided that the first control valve and the second control valve have an identical outer contour.

[0074] Such a solution makes it particularly easy to guide the two control valves in a common valve channel.

[0075] Furthermore, the two control slides positioned one behind the other are advantageously positioned in such a way that the first control slide and the second control slide can be positioned directly adjacent to each other in a combined position and can be moved together in the direction of displacement.

[0076] Furthermore, in the case of the two control valves arranged one behind the other, it is provided that the first and the second control valve can be positioned at a distance from each other in a separating position, forming an intermediate space.

[0077] Furthermore, the invention relates to a method for operating a compressor unit comprising a screw compressor with a compressor housing, a screw rotor chamber arranged in the compressor housing, at least one screw rotor arranged in the screw rotor chamber and rotatably mounted on the compressor housing about a screw rotor axis, which receives gaseous medium supplied via a low-pressure chamber arranged in the compressor housing with an initial volume and discharges it compressed to a final volume in the region of a high-pressure chamber arranged in the compressor housing, and at least one control slide arranged in a slide channel of the compressor housing and adjacent to the screw rotor, which is moved in a displacement direction parallel to the screw rotor axis and influences the final volume and / or the initial volume, wherein, according to the invention, a compressor operating control unit is provided on the screw compressor.with which a compressor operating function supporting the operation of the compressor unit is performed.

[0078] An advantageous variant of the method provides that the at least one compressor operating function is a parameter acquisition function and that, in particular, at least one of the function parameters such as: is required to execute the parameter acquisition function. The pressure of the medium on the inlet side of the screw compressor, the temperature of the medium on the inlet side of the screw compressor, the pressure of the medium on the outlet side of the screw compressor, the temperature of the medium on the outlet side of the screw compressor, the position of at least one control valve, the position of all control valves, the lubricant temperature, the lubricant flow rate, the lubricant differential pressure at the lubricant filter, the lubricant level in at least one lubricant inlet, the speed of the drive motor, the temperature of the drive motor, the phase angle of the drive motor, the voltage at the drive motor, and the current consumption of the drive motor are recorded.

[0079] Another advantageous variant of the method provides that a further compressor operating function is a protective function, that at least one parameter acquisition function is performed to execute the protective function, and that the at least one function parameter is compared with at least one reference parameter, and that if the at least one reference parameter is exceeded or fallen below, a warning message and / or a shutdown of the screw compressor occurs.

[0080] One suitable variant of the procedure provides that at least one compressor operating function is a control function and that, in particular, at least one of the units such as the following is used to execute the control function: a control valve drive, a motor control, a lubricant cooling system, an injection element for compressed medium for additional cooling, and a valve control unit for the control valves are controlled.

[0081] In one variant of the procedure, it is particularly advantageous that the at least one compressor operating function is an operating state preselection function, in which a control function is executed on the basis of at least one request signal and / or at least one function parameter.

[0082] Furthermore, in one variant of the procedure, it is provided that the compressor operating function is an operating condition monitoring function and that, in particular, for the execution of the operating condition monitoring function, the execution of at least one parameter acquisition function and / or at least one protection function and / or at least one control function is recorded.

[0083] For monitoring purposes, a variant of the procedure is designed such that the recording of at least one functional parameter and / or the execution of at least one protective function and / or the execution of at least one control function takes place over time.

[0084] For communication, one variant of the procedure provides that the compressor operating control unit is equipped with a communication unit which exchanges data with external devices, whereby the communication unit exchanges the data in particular via wired and / or wireless connections.

[0085] Furthermore, in one variant of the procedure, it is advantageous if the compressor operating control unit with at least one visualization unit displays at least one execution state of at least one compressor operating function or its result.

[0086] Further variants of the method according to the invention result from the features explained above in connection with the compressor unit.

[0087] Further features and advantages of the invention are the subject of the following description and the graphic representation of some exemplary embodiments.

[0088] The drawing shows: Fig. 1 a perspective view of a first embodiment of a screw compressor according to the invention; Fig. 2 a section along line 2-2 in Fig. 1 Fig. 3 shows a section along line 3-3 in the area of ​​a position detection device; Fig. 4 shows an enlarged section similar to Fig. 2 in the area of ​​the position detection device and the control valve at maximum power and smallest volume ratio; Fig. 5 a representation similar to Fig. 4 at maximum delivery volume and largest volume ratio; Fig. 6 a representation similar to Fig. 4 at approximately three-quarters of the power; Fig. 7 a representation similar Fig. 4 at approximately half power; Fig. 8 a similar representation Fig. 4 at approximately one quarter of the power; Fig. 9 an enlarged view of the position detection unit and the position indicator elements in conjunction with the control slide; Fig. 10 an enlarged perspective view of a position indicator element of the position detection device; Fig. 11 a section similar to Fig. 3 by a second embodiment of a screw compressor according to the invention with control valves arranged one inside the other; Fig. 12 a schematic representation of the second embodiment of the screw compressor according to the invention with control valves arranged one inside the other similarly Fig. 4 with the largest volume ratio and highest power output; Fig. 13 a representation similar to Fig. 12 with the largest volume ratio and lowest power; Fig. 14 a representation similar to Fig. 12 at the lowest volume ratio and highest performance; Fig. 15 a schematic representation of a compressor unit of a first embodiment, comprising a screw compressor according to the first or second embodiment, which is operated with a compressor operating control unit; Fig. 16 a representation similar to Fig. 15 a second embodiment of a compressor unit and Fig. 17 a representation similar to Fig. 15 a third embodiment of a compressor unit.

[0089] A in Fig. 1 The illustrated first embodiment of a screw compressor 10 according to the invention comprises a compressor housing designated as a whole by 12, which has a suction port 14, through which a gaseous medium to be drawn in, in particular refrigerant, is drawn in and a pressure port 16, through which the gaseous medium compressed to high pressure, in particular the refrigerant, is discharged.

[0090] As in Fig. 2 and 3 As shown, in a screw rotor chamber 18 of the compressor housing 12, two screw rotors 26, 28 are provided, each rotatable about a screw rotor axis 22, 24, which interlock with their screw contours 32 and 34 and cooperate with compression wall surfaces 36 and 38 of the screw rotor chamber 18 adjacent to these on the circumferential side, in order to receive, compress and discharge a gaseous medium supplied to a low-pressure chamber 42 adjacent to the screw contours 32, 34 on the suction side into a high-pressure chamber 44 in the compressor housing 12 at high pressure.

[0091] In this process, the gaseous medium, in particular refrigerant, is enclosed in compression chambers formed between the screw contours 32, 34 and the compression wall surfaces 36, 38 adjacent to these at low pressure in an intake volume and compressed to a final volume at high pressure.

[0092] To adapt the screw compressor 10, for example to the operating conditions required in a refrigerant circuit, the operating state of the screw compressor 10 is adjusted firstly with regard to the volume ratio, which indicates the relationship between the maximum enclosed intake volume and the discharged final volume, and secondly with regard to the compressor power, which indicates the proportion of the volume flow actually compressed by the screw compressor in relation to the maximum volume flow that can be compressed by the screw compressor 10.

[0093] To adjust the operating state, during an initial, in the Fig. 2 bis Fig. 8 In the illustrated embodiment, a first control slide 52 and a second control slide 54 are arranged one behind the other in a slide channel 56 provided in the compressor housing 12, wherein the slide channel 56 runs parallel to the screw rotor axes 22, 24 and guides the first control slide 52 and the second control slide 54 in the area of ​​their guide circumferential surface 58 which does not adjoin the screw rotors 26, 28.

[0094] The first control valve 52 faces the high-pressure chamber 44 and is therefore located on the high-pressure side, and the second control valve 54 is located on the low-pressure side relative to the first control valve 52.

[0095] Each of the two control valves 52 and 54 also has a valve compression wall surface 62 adjacent to the screw rotor 26 and a valve compression wall surface 64 adjacent to the screw rotor 28, which represent partial surfaces of the compression wall surfaces 36 and 38, and housing compression wall surfaces 66 and 68 formed by the compressor housing 12, which also represent partial surfaces of the compression wall surfaces 36 and 38, to the compression wall surfaces 36 and 38, which together with the screw contours 32 and 34 contribute to the formation of the compression chambers.

[0096] The first control valve 52 and the second control valve 54 are, as in Fig. 2 as well as 4 to 8, designed in such a way that they are identical insofar as they form the slide compression wall surfaces 62 and 64 and the guide circumferential surface 58 and can therefore be guided displaceably in a displacement direction 72 parallel to the screw rotor axes 22, 24 in the slide channel 56 of the compressor housing 12.

[0097] The first control valve 52 forms an outlet edge 82 facing the high-pressure chamber 44, which determines the final volume of the compression chambers, and which can be moved in the direction of movement 72 by moving the first control valve 52 and which, through its position relative to a high-pressure-side end surface 84 of the screw rotor chamber 18, determines the final volume of the compression chambers formed and thus the volume ratio.

[0098] This principle of the slide arrangement is known and is described, for example, in WO 93 / 18307, to which reference is made regarding the description of the operating principle.

[0099] As in the Fig. 2 and 4 bis 8 As shown, the first control valve 52 and the second control valve 54 have mutually facing end faces 86 and 88, with which they, as for example in Fig. 4 and Fig. 5 shown, so that they can be placed next to each other, so that the valve compression wall surfaces 62 and 64 of the first control valve 52 and the second control valve 54 merge into each other.

[0100] Furthermore, the first control valve 52 and the second control valve 54 are guided relative to each other by a telescopic guide 92 in addition to the valve channel 56, which has an inner guide body 94 and a guide receptacle 96, wherein the guide receptacle 96 is provided in the first control valve 52 and the guide body 94 is held on the second control valve 54 and projects beyond its end face 88, so that it can engage in the guide receptacle 96 in the first control valve 52.

[0101] Furthermore, a compression spring 104 is preferably provided in an interior space 102 of the second control slide 54 surrounding the guide body 94, which serves to act on the first control slide 52 relative to the second control slide 54 in such a way that the end faces 86 and 88 can be moved away from each other.

[0102] To move the first control slide 52, as described in Fig. 2 A control valve drive is shown, for example designed as a cylinder arrangement 112, wherein the cylinder arrangement 112 comprises a cylinder chamber 114 and a piston 116, and wherein the piston 116 is connected to a piston rod 118, which establishes a connection to the first control valve 52, for example with an extension 122 of the first control valve 52, which is arranged, for example, on one side of the same opposite the end face 86.

[0103] Furthermore, the cylinder arrangement 112 is located in particular on a side of the first control valve 52 opposite the second control valve 54, preferably in a high-pressure-side housing section 124 of the compressor housing 12, which is arranged following the valve channel 56 and following the high-pressure chamber 44 and thus on a side of the compressor housing 12 opposite the low-pressure chamber 42.

[0104] The second control valve 54 is displaceable by a control valve drive, for example designed as a cylinder arrangement 132, wherein the cylinder arrangement 132 comprises a piston 136 movable in a cylinder chamber 134 and wherein the cylinder chamber 134 extends in particular in continuation of the valve channel 56 in a low-pressure-side housing section 142, in which drive-side bearing units for the screw rotors 26 and 28 are arranged, which can be driven, for example, via a drive shaft 144.

[0105] In particular, the piston 136 is integrally formed with the second control valve 54 and has a piston area that corresponds at least to the cross-sectional area of ​​the second control valve 54.

[0106] The low-pressure side housing section 142, which accommodates the cylinder chamber 134 for the cylinder arrangement 132 for moving the second control valve 54, is located in an area of ​​the compressor housing 12 that is arranged opposite the high-pressure side housing section 124 for accommodating the cylinder chamber 114 for the cylinder arrangement 112.

[0107] The first control valve 52 and the second control valve 54 can be pushed together by the cylinder arrangements 112 and 132 to such an extent that the end faces 86 and 88 abut each other in a combined position, and the two control valves 52, 54 can also be moved together in the combined position as a single control valve, which extends from the suction-side end surface 126 towards the pressure-side end surface 84 and whose outlet edge 82 contributes to determining the volume ratio, wherein, as in Fig. 4 As shown, the screw compressor 10 always delivers the maximum volume flow in this combined position.

[0108] Depending on the position of the outlet edge 82 relative to the end surface 84, the volume ratio can be adjusted. This ratio increases with the decreasing distance of the outlet edge 82 from the end surface 84 and reaches its maximum value when the outlet edge 82 has the smallest distance from the end surface 84 required to minimize the final volume, as for example in Fig. 5 depicted.

[0109] If the compressor output, i.e., the actual volume flow rate, is to vary additionally, this is done, as for example in Fig. 6 The diagram shows the separation of the end faces 86 and 88 by moving the control slides 52 and 54 apart into a separation position. In the separation position, the second control slide 54 is ineffective, and thus the position of the end face 86 of the first control slide 52 determines the initial volume.

[0110] However, as long as the outlet edge 82 is not in a position in which it specifies the minimum possible final volume, the ratio of the initial volume, specified by the front surface 86, to the final volume, specified by the outlet edge 82, is not variable.

[0111] However, if the first control slide is 52, as in Fig. 7 As shown, the outlet edge 82 is moved so far towards the high-pressure chamber 44 that it has the minimum distance from the end surface 84 or is even moved beyond it into an entry chamber 146 encompassed by the high-pressure chamber 44 for the first control valve 52, a variation of the initial volume 86 is possible without changing the final volume, since the latter always remains minimal.

[0112] To eliminate the effect of the second control valve 54 in the separation position, it is retracted into the housing section 142, in particular by means of the cylinder arrangement 132, wherein the cylinder chamber 134 is dimensioned such that it simultaneously includes a retraction space 148 for the second control valve 54 and thus makes it possible to move the second control valve 54 so far away from the first control valve 52 that the end face 88 no longer influences the initial volume.

[0113] The second control slide 54 thus allows the initial volume to be influenced by either having its end face 88 rest against the end face 86 of the first control slide 52 to form the combined position of the control slides 52, 54, thereby maximizing the initial volume, or by having its own end face 88 moved so far away from the end face 86 of the first control slide 52 that the initial volume is no longer influenced by the second control slide 54.

[0114] To detect the positions of the first control slide 52 and the second control slide 54, a position detection device designated as a whole by 152 is provided, which comprises a detector element 154 extending parallel to the displacement direction 72 of the control slides 52, 54 and thus parallel to the screw rotor axes 22, 24, which is able to detect the positions of position indicator elements 156 and 158.

[0115] The position indicator element 156 is rigidly coupled to the first control valve 52, specifically to an end region 162 of the first control valve 52 adjoining the end face 86, and the position indicator element 158 ​​is coupled to the second control valve 54, specifically to an end region 164 of the same adjoining the end face 88, as shown in particular in Fig. 9 depicted.

[0116] As in Fig. 10 As shown, each of these position indicator elements 156 or 158 comprises a fork body designated as a whole by 174, which, with its two fork arms 176 and 178, defines an intermediate space 182 through which the elongated detector element 154 extends. Each of these fork bodies 174 is coupled to the corresponding control slide 52, 54 via a connecting body 172 connected to the respective end region 162 or 164.

[0117] Preferably, the fork legs 176 and 178 carry magnets 184 and 186 respectively, whose magnetic field permeates the detector element 154 at the location of the magnets 184, 186.

[0118] The detector element 154 is made of a magnetostrictive material, so that the respective location 188 of the magnetic flux of the detector element 154 by the magnets 184, 186 can be determined by means of an evaluation device designated as a whole by 192, wherein the evaluation device 192 generates sound waves, for example, in the magnetostrictive detector element 154, which experience a back reflection at the locations 188 through which the magnetic fields of the magnets 184, 186 are permeated, so that the evaluation device 192 can determine the location of the locations 188 in which the magnetic flux of the magnetostrictive detector element 154 takes place, based on the travel time of the reflected sound waves.

[0119] Thus, the evaluation unit 192 can determine the position POS1 of the first control slide 52 and the position POS2 of the second control slide 54 in the displacement direction 72 in the slide channel 56.

[0120] The connecting bodies 172, which are held at the respective end regions 162, 164 of the control valves 52, 54, extend through an elongated, slot-shaped passage 194, which is formed in a housing wall 196 forming the valve channel 56 and has a length which, in the separation position, allows the second control valve 54 to be fully retracted into the insertion chamber 148 and the first control valve 52 to be positioned at minimum initial volume, i.e., a position corresponding to Fig. 8 , and allows a position of the first control valve 52 at minimum volume ratio, i.e. maximum distance of the outlet edge 82 from the pressure-side end surface 84, and also allows a position of the second control valve 54 with the first control valve 52 in the combined position at maximum volume ratio and minimum volume ratio.

[0121] Each connecting body 172 connected to the respective end region 162 and 164 of the corresponding control slide 52 or 54, together with the slot-shaped passage 194, forms an anti-rotation device for the respective control slide 52, 54 similar to a guide by a T-nut and a groove, thus eliminating the need to provide grooves in the control slides 52, 54 that interact with T-nuts projecting into the slide channel 56.

[0122] The passage 194 is always maintained at the pressure in the low-pressure chamber 42 and thus also serves to keep the control valves 52, 54 with their guide circumferential surface 58 in contact with the valve channel 56, so that the control valves 52, 54 cannot press against the screw rotors 26, 28 with the valve compression wall surfaces 62, 64 due to the high pressure forming between the valve channel 56 and the guide circumferential surface 58.

[0123] The passage 194 is sealed against higher pressures, especially high pressure, by the narrowly tolerable gap between the valve channel 56 and the guide circumferential surface 58 of the control valves 52, 54.

[0124] To accommodate the fork bodies 174 and the detector element 154, a recess 204 is provided on a side of a wall 196 of a housing base body 198 opposite the slide channel 56. This recess is covered by a lid 212, which in turn has a recess 214 facing the recess 204, so that the recesses 204 and 214 complement each other and, for example, form an elongated detector channel 216 running parallel to the direction of movement 72. The detector element 154 extends in this channel, and the fork bodies 174 are movable within it. Their fork legs 176, 178 encircle the detector element 154 on both sides and position the magnets 184, 186 such that their magnetic field passes through the detector element 154 at a specific location 188.

[0125] Preferably the cover 212 is designed such that the detector element 154 lies in its recess 214, so that the detector element 154 together with the evaluation device 192 is held exclusively on the cover 212 and can be removed with it, while the fork bodies 174 extend in the detector channel 216, in particular both in the recess 214 and in the recess 204.

[0126] In a second embodiment of a screw compressor according to the invention, as shown in Fig. 11 bis 14 The control valves 52 and 54 are shown with a different design.

[0127] In this embodiment, the second control valve 54' lies in the valve channel 56 and is guided therein by its guide circumferential surface 58'. Furthermore, the second control valve 54' forms outer valve compression wall surfaces 62' 2 and 64' 2, which directly adjoin the housing compression wall surfaces 66 and 68, with the valve compression wall surface 62' 2 bordering the screw rotor 26 and the valve compression wall surface 64' 2 bordering the screw rotor 28.

[0128] The second control slide 54' has a crescent-shaped cross-section, so that it in turn forms a slide channel 236 in which the first control slide 52' is guided with a guide circumferential surface 238.

[0129] The first control valve 52' in turn forms valve compression wall surfaces 62' 1 and 64' 1, which lie between the valve compression wall surfaces 62' 2 and 64' 2 and connect directly to the valve compression wall surfaces 62' 2 and 64' 2, so that the valve compression wall surface 62' 1 borders the screw rotor 26 and the valve compression wall surface 64' 1 borders the screw rotor 28.

[0130] Thus, the valve compression wall surfaces 62' 2 and 64' 2 of the second control valve 54' and the valve compression wall surfaces 62' 1 and 64' 1 of the first control valve 52' complement the housing compression wall surfaces 66 and 68 to form the compression wall surfaces 36 and 38, which are arranged enclosing the screw contours 32 and 34 respectively.

[0131] The first control valve 52' also forms the outlet edge 82', which is arranged facing the high-pressure chamber 44 and which determines the final volume by its distance from the closing surface 84 in a manner comparable to the first embodiment.

[0132] The second control valve 54' influences the initial volume by the position of inlet edges 242 of the valve compression wall surfaces 62 2 and 64 2, and in particular their distance from the low-pressure side end surface 126.

[0133] In this embodiment, the first control valve 52' is controllable by a cylinder arrangement 132', which is arranged particularly on the suction side, wherein the piston 136' is integrally formed on the first control valve 52' and is movable in the cylinder chamber 134', while the second control valve 54' is controllable by a cylinder arrangement 112', which is arranged particularly on the pressure side.

[0134] Such a slide arrangement is known and is described, for example, in DE 32 21 849 A1, to which reference is made with regard to the description of the operating principle.

[0135] In the same way as in the first embodiment, the positions of the first control slide 52' and the second control slide 54' can be detected by the position detection device 152, wherein position indicator elements 156 and 158 are also coupled to the first control slide 52' and the second control slide 54' respectively, via connecting bodies 172 which are firmly connected to these control slides 52' and 54' and which, in the same way as in the first embodiment, extend through the passage 194, so that the position indicator elements 156 and 158 are movable in the detector channel 216 along the detector element 154 and, in the same way as in the first embodiment, the positions of the position indicator elements 156 and 158 can be detected via the evaluation device 192.

[0136] In this case, the position indicator elements 156 and 158 are preferably designed as fork bodies 174 in the same way as in the first embodiment and are provided with magnets 184 and 186.

[0137] Furthermore, in the second embodiment, all elements that are identical to those of the first embodiment are provided with the same reference numerals, so that full reference can be made to the explanations of the first embodiment in this respect.

[0138] The screw compressors according to the preceding exemplary embodiments further comprise, as for example in a first embodiment of a compressor unit in Fig. 15 The figure shows a lubricant supply system 260, which separates lubricant from a stream of high-pressure compressed medium MH exiting the screw compressor 10 by means of a lubricant separator 262, cools it in a lubricant cooler 264, filters it in a lubricant filter 266 and then connects it to a lubricant port 268 at the schematically shown in Fig. 15 feeds into the compressor housing 12 shown.

[0139] The lubricant supply can be controlled by a controllable valve 272 assigned to the lubricant supply system 260.

[0140] From the lubricant connection 268, a lubricant supply line 274 leads to several lubricant inlets 282, 284, 286, 288, in order to supply the lubrication points of the screw compressor 10, for example formed by a shaft seal 292 of the drive shaft for the screw rotors 26, 28, low-pressure side bearings 294 for the screw rotors 26, 28, a lubricant injection 296 for the screw rotors 26, 28 and high-pressure side bearings 298.

[0141] Furthermore, lubricant for operating the cylinder arrangements 112 and 132 can also be diverted from the lubricant supply line 274, since the lubricant is under high pressure.

[0142] The lubricant supply system 260 is also monitored by a lubricant sensor SS, which is assigned, for example, to one of the lubricant inlets 282, 284, 286, 288, in this case to the lubricant inlet 282.

[0143] Preferably, the lubricant sensor SS is designed as an optical lubricant presence sensor and detects the presence of lubricant, for example, in the lubricant inlet 282 representatively and for the other lubricant inlets 284, 286, 288.

[0144] For the safe and reliable operation of one of the preceding embodiments of a screw compressor 10, according to the first embodiment of the compressor unit, which is in Fig. 15 As shown, an electronic compressor operating control unit 240 is provided in a control housing 230 arranged on the compressor housing 12, which is thus able to perform a variety of compressor operating functions.

[0145] A compressor operating function is a parameter acquisition function according to which, for example, the following functional parameters are acquired by means of sensors and devices provided for this purpose.

[0146] The compressor operating control unit 240 uses sensors SPN and STN arranged on the inlet or low-pressure side to detect the pressure PN of the gaseous medium to be compressed on the inlet or low-pressure side, or the temperature TN of the gaseous medium to be compressed on the inlet or low-pressure side of the screw compressor 10.

[0147] Furthermore, the compressor operating control unit 240 uses sensors SPH and STH arranged on the outlet side or high-pressure side to detect the pressure PH of the compressed gaseous medium or the temperature TH of the compressed gaseous medium on the outlet side or high-pressure side of the screw compressor 10.

[0148] The parameter acquisition function also includes the following: Fig. 15 The connection shown between the compressor operating control unit 240 and the evaluation unit 192 allows for the detection of the positions POS1 and POS2 of the control slides 52 and 54 respectively along the displacement direction 72 in the slide channel 56.

[0149] To detect the rotational speed of the screw rotors 26, 28, in the first embodiment according to Fig. 15 A vibration sensor SSW connected to the compressor operating control unit 240 is arranged on the compressor housing 12, which generates a signal DS proportional to the speed of the screw rotors 26, 28, which is detected by the compressor operating control unit 240.

[0150] Furthermore, as part of the parameter acquisition function, the presence of lubricant is detected by the lubricant presence signal SP of the lubricant sensor SS transmitted to the compressor operating control unit 240, which is an indication of the functioning lubricant supply.

[0151] As part of the execution of a compressor operating function as a protective function, the compressor operating control 240 compares the function parameters recorded as part of the parameter acquisition function with the reference parameters specified by the compressor operating control unit 240 in order to recognize whether at least one of the reference parameters is exceeded or fallen below and whether this may result in the screw compressor being switched off.

[0152] For example, the compressor operating control unit 240 compares the pressure PN and temperature TN on the inlet side or low-pressure side, as well as the pressure PH and temperature TH on the outlet side or high-pressure side, with predefined reference parameters, such as reference parameters defined by the operating limits of the screw compressor, and determines whether the screw compressor is being operated within the intended operating limits.

[0153] In addition, as part of the protective function, the compressor operating control unit 240 checks whether the lubricant presence signal SP is present and thus whether there is a sufficient lubricant supply to the screw compressor 10.

[0154] As part of the execution of a compressor operating function as a control function, the control slides 52, 54 are moved to operate the screw compressor 10 in a specific operating state, in particular in a specific volume ratio and with a specific power.

[0155] To move the control valves 52 and 54 into their designated positions, the compressor operating control unit 240 uses the actual positions POS1 and POS2 of the control valves 52, 54, which are recorded by the connection with the position detection device 152 and the evaluation device 192 within the framework of the parameter detection function, in order to move the control valves 52, 54 to defined positions and hold them in these positions based on the knowledge of these positions POS1 and POS2.

[0156] The control function of the compressor operating control unit 240 is, as described in Fig. 1 , 2 and 15 The cylinder arrangements 112 and 132 are shown to be controllable in order to position the control slides 52, 54.

[0157] For this purpose, for example, the compressor operating control unit 240 provides solenoid valves ML1 and ML2 that can be controlled to control the cylinder arrangement 112, and solenoid valves MV1 and MV2 that can be controlled to control the cylinder arrangement 132.

[0158] This makes it possible to position the control valves 52, 54 with the compressor operating control unit 240 in a position-controlled manner, i.e., for example, to precisely approach and maintain the corresponding positions of the control valves 52, 54 for certain desired operating states of the screw compressor 10.

[0159] As part of its control function as a compressor function, the compressor operating control unit 240 also controls the lubricant supply through the lubricant supply system 260 by means of the controllable valve 272.

[0160] The compressor operating control unit 240 is also designed in such a way that it can be connected to a control unit for a drive motor 300, in particular an electric motor, for driving the screw compressor 10 according to the invention, wherein the drive motor 300 is controlled, for example, by a motor control unit 302, comprising in particular a frequency converter, so that the drive motor 300 can not only be switched on and off but can also be operated in a speed-controlled manner by the motor control unit 302.

[0161] This makes it possible to operate the drive motor 300 via the compressor operating control unit 240, depending on the operating state of the screw compressor 10.

[0162] Preferably, the compressor unit according to the invention is operated by a system control 310, which, particularly in the case of the use of the screw compressor 10 according to the invention in a cooling circuit or refrigeration circuit, transmits the power requirement placed on the screw compressor 10 by the compressor operating control unit 240 via a communication unit 312.

[0163] The performance requirement is defined by the plant control system 310 on the one hand by the state variables of the flow of medium MN to the screw compressor 10 at low pressure and the flow of medium MH away from the screw compressor at high pressure, whereby, for example, in the Fig. 15 In the illustrated embodiment of the compressor unit, the system control 310 detects the pressure of the flow of the medium MN at low pressure by the pressure sensor ASPN and the temperature of the flow of the medium MN at low pressure by the temperature sensor ASTN.

[0164] In addition, the system control 310 detects the pressure of the medium MH at high pressure through the pressure sensor ASPH and the temperature of the medium MH at high pressure through the temperature sensor ASTH.

[0165] Based on these or possibly other sensor data or parameters, the plant control unit 310 determines a request signal AS, which it transmits via the communication unit 312 to the compressor operating control unit 240.

[0166] In this case, the compressor operating control unit 240 works with an additional compressor operating function as an operating state specification function.

[0167] In this operating state specification function, the requirement variable AS and / or one or more of the function parameters recorded within the parameter acquisition function are used to define operating states and to achieve and maintain these operating states by executing at least one of the control functions.

[0168] The functional parameters considered are the positions POS1 and POS2 of the control slides 52, 54 and the speed of the drive motor 300, and based on the operating states then achieved by the control function, the functional parameters are again recorded using the parameter acquisition function, and based on these operating states, the protection function is executed by monitoring the individual functional parameters and comparing the functional parameters with the reference parameters as already described.

[0169] In order to be able to display the recorded operating parameters to an operator of the compressor unit, for example, the compressor operating control unit 240 communicates with a visualization unit 322 which is able to display the operating parameters either as such or through graphical elements, such as bar or pie charts.

[0170] Furthermore, the visualization unit 322 is also capable of displaying other compressor operating functions, in particular their execution status.

[0171] Another compressor operating function is an operating condition monitoring function in which the compressor operating control unit 240 records the execution of one or more compressor functions over time, so that, for example, in the event of a malfunction, the recorded function parameters, and / or the executed protection functions, and / or the executed control functions and / or the operating states can be traced.

[0172] In a second embodiment of a compressor unit according to the invention, illustrated in Fig. 16 , those elements which are identical to those of the first embodiment are provided with the same reference numerals, so that in this respect reference can be made in full to the description of the first embodiment.

[0173] In contrast to the first embodiment, the vibration sensor SSW is not provided in the second embodiment and instead the speed signal DS is determined from the frequency with which the frequency converter of the motor control 302 drives the drive motor 300.

[0174] Furthermore, a temperature sensor STM is assigned to the drive motor 300, which generates a temperature signal TM, via which the compressor operating control unit 240' is able to detect the temperature of the drive motor 300.

[0175] Furthermore, the phase position, i.e., the direction of rotation, of the drive motor 300 is also detected by the compressor operating control 240'.

[0176] Furthermore, the lubricant supply device 260' is assigned a sensor STSM which detects a temperature TSM of the lubricant supplied in the lubricant supply device 260', so that the compressor operating control unit 240' is also able to detect this temperature TSM of the lubricant.

[0177] In the lubricant supply device 260' a flow sensor SSSM is arranged, which detects the flow of the lubricant and generates a signal for the lubricant flow SSM, by means of which the lubricant flow in the lubricant supply device 260' can be detected by the compressor operating control unit 240'.

[0178] The SSSM lubricant flow sensor can also be designed as a differential pressure sensor.

[0179] Furthermore, pressure sensors SPSM1 and SPSM2 are assigned to the lubricant filter 266, with which a differential pressure Δ PSM at the lubricant filter 266 can be determined, whereby the compressor operating control unit 240' also detects this differential pressure Δ PSM.

[0180] Preferably, in the lubricant supply system 260', the lubricant cooling 264 can also be controlled by a valve 332, which is also connected to the compressor operating control unit 240'.

[0181] Finally, the screw rotors 26, 28 are also assigned an injection 334 for compressed, high-pressure medium, which can be controlled by a valve 336, whereby the injection of compressed and high-pressure medium into the compressor volumes enclosed by the screw rotors enables additional cooling of the screw rotors 26, 28.

[0182] As part of its parameter acquisition function, the compressor operating control 240 also acquires, in addition to the parameters explained in connection with the first embodiment, the speed DS of the frequency converter of the motor control 302, the phase position PL of the drive motor 300 and also the temperature TM of the drive motor 300.

[0183] In addition, as part of the parameter acquisition function, the compressor operating control 240' also records in particular the temperature TSM of the lubricant in the lubricant supply device 260', the lubricant flow SSM, as well as the pressure drop Δ PSM at the lubricant filter 266 of the lubricant supply device 260'.

[0184] As part of the protection function, for example, the phase angle PL of the drive motor 300 is compared with the specified phase angle, i.e., the intended direction of rotation, and the temperature TM of the drive motor 300 is compared with a reference value. If, for example, the phase angle PL deviates from the specified phase angle and / or the temperature TM exceeds the reference value, the motor control 302 triggers the shutdown of the drive motor 300.

[0185] Furthermore, as part of the protective function, the temperature TSM of the lubricant is monitored and compared with a reference value in order to detect an excessively high temperature of the lubricant.

[0186] Furthermore, as part of the protective function, the lubricant flow rate SSM and / or the differential pressure Δ PSM at the lubricant filter 266 are recorded and compared with a reference value in order to determine, for example, whether the lubricant flow rate SSM is sufficient or too low and whether, for example, the lubricant filter 266 is heavily contaminated, so that in this case a warning is issued, for example displayed on the visualization unit 322.

[0187] As part of the control function, in addition to the previous functions of the compressor operating control unit 240', the speed of the drive motor is also controlled via the frequency converter of the motor control 302 and, if necessary, the valve 332 of the lubricant cooling 264 is controlled to prevent the temperature TSM of the lubricant in the lubricant supply device 260' from becoming too high or too low.

[0188] In addition, the control function also includes the control of valve 324 for the injection of refrigerant into the compressor volumes of the screw rotors 26, 28 in order to cool them additionally if necessary.

[0189] In a third embodiment of the compressor unit, shown in Fig. 17 , all those elements that are identical to the first and second embodiments are provided with the same reference numerals, so that full reference can be made to them with regard to the description of the same.

[0190] In contrast to the first and second embodiments, in the third embodiment of the compressor unit the drive motor 300' is integrated into the compressor housing 12' and is, for example, cooled by the inlet-side flow of the medium MN at low pressure before it is compressed by the screw rotors 26, 28.

[0191] The frequency converter with motor control 302' can be arranged on the compressor housing 12' in any way.

[0192] In one case, for example, the frequency converter with the motor control 302' is integrated into the compressor housing 12' and is thus permanently connected to the compressor operating control unit 240", so that the compressor operating control unit 240" can communicate permanently with the frequency converter and, for example, receives from the frequency converter not only the speed DS of the drive motor 300, its phase position PL, but also, in particular, the voltage UM at the drive motor 300 and the current consumption IM of the drive motor 300.

[0193] Furthermore, the compressor operating control unit 240" functions in the same way as described in connection with the preceding embodiments, in particular the first embodiment.

Claims

1. A compressor unit, comprising a screw compressor (10) with a compressor housing (12) having a screw rotor chamber (18) arranged in the compressor housing (12), at least one screw rotor (26, 28) which is arranged in the screw rotor chamber (18), is mounted on the compressor housing (12) such that it is rotatable about a screw rotor axis (22, 24), receives gaseous medium having an initial volume that is supplied via a low-pressure chamber (42) arranged in the compressor housing (12), and discharges it, compressed to a final volume, in the region of a high-pressure chamber (44) arranged in the compressor housing (12), and at least one control valve (52, 54) that is arranged in a valve channel (56) of the compressor housing (12), adjoins the screw rotor (26, 28), is movable in a direction of displacement (72) parallel to the screw rotor axis (22, 24), and is configured to affect the final volume and / or the initial volume, characterised in that the screw compressor (10) has a control housing (230) that is arranged on the compressor housing (12) and in which is arranged a compressor operation control unit (240) which is configured such that it performs a compressor operating function that supports at least one operation of the compressor unit, in that the compressor operating function is an operational status monitoring function, and in that, for the purpose of performing the operational status monitoring function, performance of at least one parameter detecting function and at least one protecting function is captured, and in that capture of the at least one function parameter and performance of at least one protecting function are executed over time.

2. A compressor unit according to Claim 1, characterised in that, for the purpose of performing the operational status monitoring function, performance of at least one control function is captured, and in that performance of the at least one control function is executed over time.

3. A compressor unit according to Claim 1 or 2, characterised in that the at least one compressor operating function is a parameter detecting function, and in that, in particular for the purpose of performing the parameter detecting function, this detects at least one of the following function parameters: pressure (PN) of the medium on the inlet side of the screw compressor (10), temperature (TN) of the medium on the inlet side of the screw compressor (10), pressure (PH) of the medium on the outlet side of the screw compressor (10), temperature (TH) of the medium on the outlet side of the screw compressor (10), location (POS1; POS2) of the at least one control valve (52, 54), location (POS1; POS2) of all the control valves (52, 54), lubricant temperature (TSM), lubricant flow (SSM), lubricant differential pressure (ΔPSM) at the lubricant filter (266), lubricant level (SP) in at least one lubricant feed line (282, 284, 286, 288), speed of rotation (DS) of the drive motor (300), temperature (TM) of the drive motor (300), phase position (PL) of the drive motor (300), voltage (UM) at the drive motor (300), current consumption (IM) of the drive motor (300).

4. A compressor unit according to Claim 3, characterised in that a further compressor operating function is a protecting function, in that for the purpose of performing the protecting function at least one parameter detecting function is performed and the at least one function parameter is compared with at least one reference parameter, and in that in the event that the at least one reference parameter is exceeded or fallen below, a warning signal is given and / or switch-off of the screw compressor (10) is performed.

5. A compressor unit according to one of the preceding claims, characterised in that the at least one compressor operating function is a control function, and in that in particular for the purpose of performing the control function at least one of the following units is controlled: a control valve drive, a motor controller (302), a lubricant cooling arrangement (264), an injection element (322) for compressed medium for additional cooling, valve controlling unit for the control valves.

6. A compressor unit according to one of the preceding claims, characterised in that the at least one compressor operating function is an operational status specifying function in which, based on at least one demand signal (AS) and / or an at least one function parameter, a control function is performed.

7. A compressor unit according to one of the preceding claims, characterised in that the compressor operation control unit (240) is provided with a communication unit (312) for the purpose of exchanging data with external devices (310, 322), in particular in that the communication unit (312) exchanges the data over wires and / or wirelessly.

8. A compressor unit according to one of the preceding claims, characterised in that the compressor operation control unit (240) is provided with at least one display unit (322) that displays at least one performance status of at least one compressor operation function or the result thereof.

9. A compressor unit according to one of the preceding claims, characterised in that< / b> the screw compressor (10) has two screw rotors (26, 28), which are arranged in the screw rotor chamber (18), are mounted on the compressor housing (12) such that they are each rotatable about a screw rotor axis (22, 24), engage with one another by their screw contours (32, 34), and each cooperate with compression wall faces (36, 38) that adjoin and partly surround these, in order to receive gaseous medium having an initial volume that is supplied via a low-pressure chamber (42) arranged in the compressor housing (12) and to discharge it, compressed to a final volume, in the region of a high-pressure chamber (44) arranged in the compressor housing (12), in that the gaseous medium is enclosed in compressor chambers formed between the screw contours (32, 34) and compression wall faces (36, 38) adjoining these, at an initial volume at low pressure and compressed to a final volume at high pressure, and at least one control valve (52, 54), which is arranged in a valve channel (56) of the compressor housing (12) and adjoins both screw rotors (26, 28) at valve compression wall faces (62, 64) and is movable in a direction of displacement (72) parallel to the screw rotor axes (22, 24), and configured to affect the final volume and / or the initial volume, and / or in that in particular a location detecting device (152) is provided for the at least one control valve (52, 54), in that the location detecting device (152) has a location display element (156, 158) coupled to the at least one control valve (52, 54), in that the at least one location display element (156, 158) cooperates with a detector element (154) that extends parallel to the direction of displacement (72) of the at least one control valve (52, 54) and along which the location display element (156, 158) is movable, and in that the detector element (154) is coupled to an evaluating device (192) that detects the respective location (POS1, POS2) of the location display element (156, 158) along the detector element (154), and / or in that in particular the screw compressor (10) has two control valves (52, 54), wherein a first control valve (52) is configured to affect the final volume and a second control valve (54) is configured to affect the initial volume, in that a location detecting device (152) is provided for the two control valves (52, 54), which comprises a first location display element (156) coupled to the first control valve (52) and a second location display element (158) coupled to the second control valve (54), in that both location display elements (156, 158) cooperate with a common detector element (154) that extends parallel to the direction of displacement (72) of the control valves (52, 54) and along which the location display elements (156, 158) are movable when the control valves (52, 54) move, and in that the detector element (154) is coupled to an evaluating device (192) that detects the respective locations (POS1, POS2) of the location display elements (156, 158) along the detector element (154), and / or in that in particular the detector element (154) is arranged in a detector channel (216) running within the compressor housing (12) parallel to the direction of displacement (72), in that in particular the respective location display element (156, 158) is arranged in the detector channel (216), in that in particular the respective location display element (156, 158) is mechanically coupled to the respective control valve (52, 54) via a connecting body (172).

10. A compressor unit according to Claim 9, characterised in that the respective location display element (156, 158) cooperates contactlessly with the detector element (154).

11. A compressor unit according to one of the preceding claims, characterised in that the compressor operation control unit (240) controls a control valve drive (112, 132) for the respective control valve (52, 54) and uses the location detecting unit (152) to detect movement of the respective control valve (52, 54), in particular in that the compressor operation control unit (240) determines the location of the respective control valve (52, 54) using position control.

12. A compressor unit according to one of the preceding claims, characterised in that the compressor operation control unit (240) determines the locations (POS1, POS2) of the at least one control valve (52, 54) while taking into account at least one or more of the parameters such as pressure level (PN) on the inlet side, in particular at low pressure, pressure level (PH) on the outlet side, in particular at high pressure, temperature (TN) of the gaseous medium on the inlet side, in particular at low pressure, temperature (TH) of the gaseous medium on the outlet side, in particular at high pressure, speed of rotation (DS) of the screw rotors, power consumption of a drive motor, parameters of the gaseous medium, in particular the coolant, and limit values in use for the screw compressor.

13. A compressor unit according to one of Claims 9 to 12, characterised in that the first control valve (52) and the second control valve (54) are arranged one behind the other relative to the direction of displacement (72) thereof, in particular in that the first control valve (52) and the second control valve (54) have identical external contours, in particular in that, in a combined position, the first control valve (52) and the second control valve (54) are configured to be located directly adjoining one another and to be moved jointly in the direction of displacement (72), and in particular in that, in a separated position, the first and the second control valves (52, 54) are configured to be located at a spacing from one another, forming an intermediate space.

14. A compressor unit according to one of Claims 9 to 13, characterised in that the first control valve (52') has valve compression wall faces (62'1, 64'1) that directly adjoin one another and of which in each case one adjoins one of the screw rotors (26, 28), and in that the second control valve (54') has valve compression wall faces (62'2, 64'2) that are at a spacing from one another and of which in each case one adjoins one of the screw rotors, in particular in that the first control valve (52') is mounted on the second control valve (54'), in particular in that valve compression wall faces (62, 64) of the first control valve (52') and the second control valve (54') adjoin one another.

15. A method for operating a compressor unit comprising a screw compressor (10) with a compressor housing (12) having a screw rotor chamber (18) arranged in the compressor housing (12), at least one screw rotor (26, 28) which is arranged in the screw rotor chamber (18), is mounted on the compressor housing (12) such that it is rotatable about a screw rotor axis (22, 24), receives gaseous medium having an initial volume that is supplied via a low-pressure chamber (42) arranged in the compressor housing (12), and discharges it, compressed to a final volume, in the region of a high-pressure chamber (44) arranged in the compressor housing (12), and at least one control valve (52, 54) that is arranged in a valve channel (56) of the compressor housing (12), adjoins the screw rotor (26, 28), is moved in a direction of displacement (72) parallel to the screw rotor axis (22, 24), and affects the final volume and / or the initial volume, characterised in that provided on the screw compressor (10) is a compressor operation control unit (240) which performs a compressor operating function that supports at least one operation of the compressor unit, in that the compressor operating function is an operational status monitoring function, and in that, for the purpose of performing the operational status monitoring function, performance of at least one parameter detecting function and at least one protecting function is captured, and in that capture of the at least one function parameter and performance of at least one protecting function are executed over time.

16. A method according to Claim 15, characterised in that the at least one compressor operating function is a parameter detecting function, and in that, in particular for the purpose of performing the parameter detecting function, this detects at least one of the following function parameters: pressure (PN) of the medium on the inlet side of the screw compressor (10), temperature (TN) of the medium on the inlet side of the screw compressor (10), pressure (PH) of the medium on the outlet side of the screw compressor (10), temperature (TH) of the medium on the outlet side of the screw compressor (10), location (POS1; POS2) of the at least one control valve (52, 54), location (POS1; POS2) of all the control valves (52, 54), lubricant temperature (TSM), lubricant flow (SSM), lubricant differential pressure (ΔPSM) at the lubricant filter (266), lubricant level (SP) in at least one lubricant feed line (282, 284, 286, 288), speed of rotation (DS) of the drive motor (300), temperature (TM) of the drive motor (300), phase position (PL) of the drive motor (300), voltage (UM) at the drive motor (300), current consumption (IM) of the drive motor (300), in particular in that a further compressor operating function is a protecting function, in that for the purpose of performing the protecting function at least one parameter detecting function is performed and the at least one function parameter is compared with at least one reference parameter, and in that in the event that the at least one reference parameter is exceeded or fallen below, a warning signal is given and / or switch-off of the screw compressor (10) is performed, in particular in that the at least one compressor operating function is a control function, and in that in particular for the purpose of performing the control function at least one of the following units is controlled, such as: a control valve drive, a motor controller (302), a lubricant cooling arrangement (264), an injection element (322) for compressed medium for additional cooling, valve controlling unit for the control valves, and in particular in that the at least one compressor operating function is an operational status specifying function in which, based on at least one demand signal (AS) and / or an at least one function parameter, a control function is performed.

17. A method according to one of Claims 15 and 16, characterised in that the compressor operation control unit (240) is provided with a communication unit (312) which exchanges data with external devices (310, 322), in particular in that the communication unit (312) exchanges the data over wires and / or wirelessly.

18. A method according to one of Claims 15 to 17, characterised in that the compressor operation control unit (240) is provided with at least one display unit (322) that displays at least one performance status of at least one compressor operation function or the result thereof.

19. A method according to one of Claims 15 to 18, characterised in that a location detecting device (152) for the at least one control valve (52, 54) has a location display element (156, 158) coupled to the at least one control valve (52, 54), in that the at least one location display element (156, 158) cooperates with a detector element (154) that extends parallel to the direction of displacement (72) of the at least one control valve (52, 54) and along which the location display element (156, 158) is moved, and in that the detector element (154) uses an evaluating device (192) to detect the respective location (POS1, POS2) of the location display element (156, 158) along the detector element (154), and / or in that in particular the screw compressor (10) has two control valves (52, 54), wherein a first control valve (52) is configured to affect the final volume and a second control valve (54) is configured to affect the initial volume, in that a location detecting device (152) comprises a first location display element (156) coupled to the first control valve (52) and a second location display element (158) coupled to the second control valve (54), in that both location display elements (156, 158) cooperate with a common detector element (154) that extends parallel to the direction of displacement (72) of the control valves (52, 54) and along which the location display elements (156, 158) are moved when the control valves (52, 54) move, and in that the detector element (154) uses an evaluating device (192) to detect the respective locations (POS1, POS2) of the location display elements (156, 158) along the detector element (154), and / or in that in particular the compressor operation control unit (240) controls a control valve drive (112, 132) for the respective control valve (52, 54) and uses the location detecting unit (152) to detect movement of the respective control valve (52, 54), in that in particular the compressor operation control unit (240) determines the location of the respective control valve (52, 54) using position control.

20. A method according to one of the preceding claims, characterised in that the compressor operation control unit (240) determines the locations (POS1, POS2) of the at least one control valve (52, 54) while taking into account at least one or more of the parameters such as pressure level (PN) on the inlet side, in particular at low pressure, pressure level (PH) on the outlet side, in particular at high pressure, temperature (TN) of the gaseous medium on the inlet side, in particular at low pressure, temperature (TH) of the gaseous medium on the outlet side, in particular at high pressure, speed of rotation (DS) of the screw rotors, power consumption of a drive motor, parameters of the gaseous medium, in particular the coolant, and limit values in use for the screw compressor.