Compressor system with internal air-water cooling

Abstract

The invention relates to a compressor system (01) having a system housing (02), in which a heat-generating system component (06) is arranged, the system component (06) comprising at least one compressor stage (201) for compressing a gaseous medium. Furthermore, the compressor system (01) has an air-water cooler (12), a blower (15) generating a cooling air flow (16), and an air-conducting element, the air-conducting element conducting hot air from the system component (06) to the air-water cooler (12). According to the invention, a cooling air channel (07) is provided, which has an inlet opening (08) in an upper part of the system housing (02) and an outlet opening (09) in a lower part of the system housing (02), an upper air conducting element (13) being provided for conducting a cooling air flow (16) to the inlet opening (08) after flowing through the air water cooler (12), and a lower air conducting element (13) being provided for conducting the cooling air flow (16) to the outlet opening (09) after flowing through the air water cooler (12). And a lower air conducting element (17) is provided for conducting the cooling air flow (16) from the outlet opening (09) to the system component (06).

Description

[0001] This application is a divisional application of the invention patent application with application number "201810316479.8", application date of April 10, 2018, priority date of April 10, 2017, and invention title "Compressor System with Internal Air-Water Cooling". Technical Field

[0002] This invention relates to compressor systems with internal air-water cooling. Specifically, it relates to a screw compressor arrangement with internal air-water cooling, wherein a novel cooling concept is supported by using varying idling operating states. Finally, the invention relates to compressor systems with internal air-water cooling that further utilize adjusted pulsation dampers to specifically minimize noise emissions. Background Technology

[0003] Various designs for compressing gaseous media are known, specifically, various designs for generating compressed air are known. For example, DE 601 17 821 T2 shows a multi-stage screw compressor with two or more compressor stages, wherein each compressor stage includes a pair of rotors for compressing the gas. Additionally, two or more drives with variable speeds are provided, wherein each drive drives a corresponding compressor stage. A controller controls the speed of the drives, wherein the torque and speed of each drive are monitored so that the screw compressor delivers gas at the required flow rate and the required pressure, while simultaneously minimizing the energy consumption of the screw compressor.

[0004] EP 2 886 862 A1 describes a compressor having a motor, a drive shaft, a crank drive unit connected to the drive shaft, at least one compressed air generating device, a crankcase, and a compressed air storage container. Cooling of all components is achieved with the aid of a cooling airflow generated by a fan impeller.

[0005] EP 1 703 618 B1 illustrates a compressor system for providing compressed gaseous fluid. The compressor system includes a heat exchanger and an air-cooled electric motor, wherein the heat exchanger is used to directly or indirectly cool the gaseous fluid, and the air-cooled electric motor has a motor unit with a motor housing and a drive shaft protruding from the motor housing. The compressor is driven by the motor unit. Additionally, a fan is driven by the drive shaft, the fan including at least radially and / or axially separated first and second fan sections for conveying a first airflow and a separate second airflow. Furthermore, an upstream channel separator separates a first intake channel for the first airflow from a second intake channel for the second airflow, wherein the first airflow is drawn in from the first fan section, and the second airflow is conveyed through the second fan section. The airflows enter the corresponding associated fan sections at spatially separated cross-sections and exit from them again without mixing. The second airflow is conducted via a heat exchanger (25). The heat exchanger is arranged upstream of the second airflow from the fan.

[0006] Typically, such compressor systems always require the dissipation of a significant amount of heat, more or less, to prevent overheating of individual components or the entire system. Up to this point, the entire system is cooled by cooling air, in which hot exhaust gases are discharged. Some systems additionally include a heat exchanger, where a secondary cooling medium absorbs heat from the compressor's main cooling circuit and transfers it to the outside. Thus, the dissipated heat can be recovered for use by external consumers. All systems share a common problem: air vents and exhaust vents are necessary for the circulation of cooling air, which allow noise to escape from the compressor system, necessitating expensive noise protection measures. Furthermore, the supply of cooling air can lead to damage within the system, for example, corrosion due to accumulated dirt or moisture condensation. These two main problems arising from the necessity of cooling air ventilation are further amplified by the components and functions used here.

[0007] Therefore, additional acoustic emissions occur, specifically in the case of machining based on the displacement principle. Due to the intermittent exhaust process on the pressure or exhaust side of the compressor, problems arise such as undesirable pulsation in downstream components like pipelines, coolers, and pressure vessels, i.e., pressure changes occur. This leads to considerable noise emissions, structure-based propagation noise, sound transmission, and noise emission. Because the exhaust operation is pulsed, the harmonics of the fundamental frequency of the pulsation are also more pronounced, in some cases even stronger than the fundamental frequency itself.

[0008] From DE 699 20 997 T2, a pulsation damper for a pump is well known for its singular solution to the problem caused by pulsation. This pulsation damper comprises a device body and a diaphragm, wherein the diaphragm divides the interior of the device body into a fluid chamber and a gas chamber. The fluid chamber temporarily stores the fluid to be pumped by the piston pump, and the gas chamber is filled with gas to suppress pulsation and expands and contracts to change the volume of the fluid chamber. As a result, pulsation caused by the output pressure of the liquid to be pumped is suppressed.

[0009] In fact, simple pulsating dampers are also known. These simple dampers are essentially formed as long, extended tubes with absorber material installed inside, and are intended to suppress both sound absorption and reflection. However, these known sound dampers have several drawbacks. First, the large length of the absorption section is crucial to achieving adequate damping. Because the absorber material exhibits constant damping along its length, sound damping occurs gradually from the entry point to the exit point of the damper. This means that in the relatively ingress region of the sound damper, a significant amount of sound is dissipated to the outside through the casing. Furthermore, specifically at high frequencies, sound penetrates the long, extended damping tube, allowing pulsations of a given frequency to pass through the absorber almost undamped.

[0010] The significant heat development that occurs in idling compressor systems necessitates consideration of this heat when determining cooler dimensions. Therefore, in practical applications, specifically in the case of multi-stage screw compressors idling, when no compressed air is being drawn from the downstream system, the delivery of additional media is stopped to prevent pressure buildup. However, the compressor should not be completely shut off during idling, as the necessary subsequent delivery of compressed air is anticipated for a very short time. To facilitate idling operation, the throttle valve in the suction line is typically closed, and the flow is diverted to the first compressor stage only via a bypass. In most cases, a so-called suction regulator performs these functions, located at the inlet of the first compressor stage. Simultaneously, on the output side, and thus at the output of the second compressor stage, the exhaust valve is opened to the atmosphere, allowing the second compressor stage to deliver air against atmospheric pressure. The pressure conditions in both compressor stages remain constant, resulting in nearly identical discharge temperatures for both stages. The high energy consumption and waste heat generated by the compressor are disadvantages of this idling control.

[0011] Therefore, the primary problem addressed by this invention is to provide a compressor system with improved cooling that avoids the disadvantage of supplying large amounts of ambient air as cooling air. In doing so, this invention also aims to promote the recovery of waste heat from the compressor system. Similarly, this invention addresses the problems of reducing noise emissions and energy consumption in the compressor system.

[0012] The problem mentioned is solved by the compressor system according to the appended claim 1. Preferred embodiments are mentioned in the dependent claims. Summary of the Invention

[0013] The compressor system of the invention has a system housing in which several heat-generating system components are arranged. These include at least one compressor stage (e.g., a twin-screw compressor with two compressor stages) that compresses a gaseous medium, specifically producing compressed air. The system housing further includes an air-water cooler, a blower, and an air conduction element, wherein the blower generates a cooling airflow, and the air conduction element guides the air heated by the system components to the air-water cooler. At least one cooling air passage is disposed in the system housing, the cooling air passage having an inlet opening in the upper section of the system housing and an outlet opening in the lower section of the system housing. An upper air conduction element is provided in the system housing to conduct the cooling airflow through the air-water cooler to the inlet opening of the cooling air passage. Additionally, a lower air conduction element is provided to conduct the cooling airflow from the outlet opening of the cooling air passage to the heat-generating system components.

[0014] Typically, the system housing contains numerous system components that generate heat during operation. Among these components, depending on the compressor system design, are, for example, air-cooled drive motors, fittings and piping, pulsation dampers, oil pans, actual compressors with several compressor stages if necessary, gear stages, etc. Heat also develops through electronic components typically integrated into the switch cabinet; in a preferred embodiment, these electronic components can also be integrated into the system housing.

[0015] For the purpose of cooling the interior of the cooling system housing, cooling airflow is conducted into the interior of the cooling system housing, and this cooling airflow dissipates heat from the system components. In contrast to the prior art, these cooling airflows are not dissipated to the outside through housing openings, but are instead purposefully conducted to the air-water cooler inside the housing.

[0016] In an air-water cooler, the water circuit provides cooling for the air. Cooling air is conducted through cooling air channels and distributed and purposefully supplied from the cooling air channels to the system components to be cooled.

[0017] Many beneficial effects arise from the design of the compressor system proposed in this invention. For example, no openings are needed in the system housing to draw in large quantities of cooling air and dissipate it into the surrounding environment. Therefore, the compressor system emits a low noise level, simplifying the requirements to be met in situ within the installation area. Furthermore, since waste heat is almost entirely supplied to the air-water cooler, approximately 97% of the accumulated compressor waste heat is transferred to the cooling water and supplied to the heat recovery system. Because the insufficient absorption of cooling air from external environmental conditions has a relatively small impact on the compressor system, it is easier to install the compressor system in external areas or in particularly harsh environments. The thermal state of the compressor system is almost solely determined by the conditions of the cooling water supplied from the outside to the air-water cooler. In this way, heating of the compressor system is possible even when it is off (anti-freeze), with heat transferred to the internal air cooler via the cooling water through an external water circuit, and thus warm air delivered through the compressor system. Additionally, problems that can be caused by polluted air or excessively humid ambient air are avoided.

[0018] The proposed compressor system architecture and the integrated ventilation concept implemented with it can be used with all types of compressor systems (oil-filled, water-filled), wherein the water cooling system is used to cool the heat generated at the compressor stage. The heat inside the system is supplied to the water cooling system.

[0019] According to a preferred embodiment, the air-water cooler is provided by the same external cooling circuit used for the compressor stage of the compressor system. The air-water cooler can be connected in series or in parallel with the cooling circuit of the compressor stage during the process.

[0020] A preferred embodiment of the compressor system is characterized by an air-water cooler located above the heat-generating system components, and a blower located above the air-water cooler to draw in cooling airflow through the cooler and supply it to the inlet opening of the cooling air passage. By operating the accumulated waste heat automatically upwards, the air conduction element can be confined to a small guide plate. Preferably, the air conduction element is formed from a portion of the inner wall of the system housing and / or frame components, and this air conduction element can also function as a bearing.

[0021] A particularly advantageous embodiment is one in which the cooling air passage extends at least in a portion of the door or door of the sealed housing. When the door is opened, this portion automatically rotates open, allowing unobstructed access to other system components. Maintenance can be easily performed in this manner.

[0022] In one embodiment, a cooling air passage extends in a portion of the bottom of the housing and has several outlet openings thereon that allow cooling air to be released upwards into the housing. Similarly, if a particular system component is required to be supplied with cooling air laterally, lateral outlet openings may be provided in a portion of the cooling air passage in a vertically extending door.

[0023] In one advantageous embodiment, the system housing is largely hermetically isolated from the environment. The cooling airflow then circulates almost exclusively within the system housing. The compressor stage is, of course, connected to an intake support open to the environment to draw in the air to be compressed.

[0024] In one improved embodiment, the system components that generate heat include electronic circuitry. In this case, the circuitry is cooled by a cooling airflow circulating within the system housing. Alternatively, the circuitry can be housed in a separate switch cabinet with its own cooling system.

[0025] The improved implementation is characterized by the inclusion of a pulsation damper as a system component. The pulsation damper is suitable for suppressing pulsations and noise generation in a gaseous medium flow supplied by a compressor. The pulsation damper first has a housing extending along a central axis, having a medium flow inlet and a medium flow outlet. Additionally, several sleeve-shaped absorption elements, composed of sound-absorbing material, are provided and arranged concentrically within the housing. In this respect, this pulsation damper significantly deviates from known dampers, as the prior art uses only a single absorption element or several absorption elements arranged continuously along the axis. Each sleeve-shaped absorption element has an inlet region and an outlet region positioned axially spaced apart from each other, preferably arranged on opposite faces of the absorption elements. The inlet region of the foremost absorption element in terms of flow is connected to the inlet region of subsequent absorption elements in terms of flow, and the outlet region of the last absorption element in terms of flow is connected to the medium outlet of the damper housing. Between the corresponding radially adjacent wall portions of the different absorber elements, in each case, there remains a flow chamber through which the medium flow is conducted. Through this design, several absorber elements thus form several stages, in which the absorber elements are arranged in a nested manner. Each of these stages functions more or less as an individual absorber. The medium flow changes direction multiple times within the damper, preferably flowing in a meandering pattern along the individual absorber elements.

[0026] A significant advantage of the pulsating damper lies in the fact that the overall installation length is greatly reduced through the nested arrangement of the absorbing elements and the resulting meandering conduction of the medium flow. In cases where the overall system damping is comparable, the damper of this invention is more than half the length of a conventional damper with a straight-guided medium flow. Therefore, this damper can be integrated particularly easily into a system housing and can be used within the system housing to utilize cooling airflow for heat dissipation.

[0027] According to one embodiment, the absorbing elements are composed of the same sound-absorbing material, such that they all act within the same frequency range. In a modified embodiment, the individual absorbing elements are coordinated to suppress different frequency ranges, specifically by using different sound-absorbing materials. Preferably, the absorbing elements are composed of mineral materials, metal or plastic structures, or metal or ceramic foams, wherein a chamber-like structure is advantageous. Similarly, multilayer absorbent material coatings can be used.

[0028] A preferred embodiment of the pulsation damper uses rotationally symmetric absorbing elements, which are joined like a telescope and axially arranged and fixed within the damper housing. However, in modified embodiments, the absorbing elements may also have rectangular or polygonal cross-sections. It is particularly advantageous if at least three or more absorbing elements are arranged in a ring around each other, wherein, by comparison, there is still a difference in each case between the inner diameter of the respective outer absorbing element and the outer diameter of the inner absorbing element, to accommodate the flow chamber there, for example, with a width of 5-10 mm. The absorbing elements preferably extend in nearly equal axial lengths, such that at least 80%, preferably at least 90%, of the longitudinal extent of the absorbing elements axially overlaps.

[0029] According to one embodiment, the inlet and outlet regions of the pulsation damper are each arranged in front of the absorber element, wherein in each case the flow direction of the medium undergoes a 180° reversal during the transition from one absorber element to the next. Due to the nested arrangement of the sleeve-shaped absorber elements in each case of the transition between adjacent absorber elements, an increased profile of the medium flow can be achieved (even with a constant gap width in the flow chamber), resulting in a decrease in flow velocity as a result of additional damping. According to this design, twice the penetration cross-sectional area can be easily achieved, and consequently, different decelerations from one stage to the next can also be easily achieved. Similarly, the reversal of the medium flow during the overlap from one absorber element to the next can be actively utilized to improve damping performance, because due to the reversal, there is no direct "line of sight" between the medium flow inlet and outlet, which prevents higher-frequency pulsations from being directly "transmitted" to downstream components.

[0030] By using sleeve-shaped absorption elements with annular flow chambers retained between them, a generous cross-section can be achieved for flow conduction of the medium, thereby generating minimal pressure loss.

[0031] An advantageous embodiment is characterized by the fact that the foremost absorbing element of the pulsating damper, in terms of flow, is arranged radially inward, and the last absorbing element, in terms of flow, is arranged radially outward. Preferably, the damper housing has an absorbing element receiving area, a front plate, and a flange, wherein the absorbing element receiving area has a circular cross-section; the medium inlet on the front plate is configured as a central inlet opening, which flows to the central inlet area of ​​the foremost absorbing element, in terms of flow; and the flange faces the front plate, forming a medium outlet and an annular outlet area of ​​the last absorbing element, in terms of flow, flowing into the flange. Since the medium inlet to the damper is located in the internal region in this design, the location with the maximum acoustic energy is here, i.e., further away from the outer damper housing wall. In a damper equipped with three absorbing elements, the next stage in the flow direction is still inside the damper. In the last stage formed by the absorbing elements adjacent to the damper housing, the acoustic energy is then structured such that the acoustic energy emitted from the damper housing inside the system housing is minimized. Since there is no longer a need for ventilation openings in the system housing, the acoustic emission generated by the entire compressor system is minimized.

[0032] According to a preferred embodiment of the pulsation damper, the ratio of the axial length of each absorbing element to the maximum cross-sectional area (e.g., diameter) is less than 5, preferably less than 2.5.

[0033] Particularly preferably, this ratio is less than 1 in the radially furthest absorbing element, preferably less than 0.75. Similarly, it is advantageous if the ratio of the total axial outward length of the pulsation damper to the length of the path through which the medium flows through the absorbing element is less than 1, preferably less than 0.5.

[0034] An improved embodiment of the pulsation damper is characterized by the fact that one or more of the absorbing elements have an additional hollow space that acts as a resonator chamber. Preferably, the resonator chamber extends at an angle into the flow chamber, and reflection and resonance effects can be used to achieve additional pulsation and acoustic damping.

[0035] Obviously, if the amount of heat dissipation on the system components is as small as possible, the cooling achieved in the compressor system does not necessarily need to be measured as effectively as the size of the air-water cooler and the efficiency of the blower. This is aided by the fact that the compressor accumulates a minimal amount of heat during idling. In the case of a multi-stage screw compressor, this is achieved by altering the actuation of the compressor stages, which will be explained in detail below. Therefore, this method can be applied to the compressor system of the present invention working with a screw compressor having at least a first compressor stage and a second compressor stage, wherein the first compressor stage compresses the gaseous medium and conducts it to the second compressor stage, which further compresses the medium. Thus, from the perspective of the flow direction of the medium, the first compressor stage precedes the second compressor stage. In most cases, such a screw compressor precisely has two compressor stages; however, designs with more than two stages are also possible. Furthermore, implementing this method requires that both compressor stages be driven independently and at adjustable speeds, i.e., each compressor stage is driven by a speed-adjustable drive unit, specifically a direct drive unit, so that distribution gears can be omitted.

[0036] In the first step, a suitable transducer is used to record the volumetric flow rate of a compressed gaseous medium that is removed at the outlet of the second compressor stage or discharged at a subsequent unit. During this process, the removed volumetric flow rate can be determined using direct volumetric flow rate measurement, or indirectly, for example, by pressure conditions obtained from the outlet of the second compressor stage or by the torque / drive flow occurring at the drive unit of the second compressor stage.

[0037] During normal load operation, a volumetric flow rate is removed, which can fluctuate between the maximum value designed for the screw compressor and a predetermined minimum value. During this load operation, the screw compressor is regulated in a known manner, including the fact that the speeds of the drive units of the two compressor stages can vary within a predefined range. If the removed volumetric flow rate decreases within the range between the maximum and the predetermined minimum value during load operation, the compressor system controller reduces the speeds of the two compressor stages; and if the volumetric flow rate increases within this range, the controller again increases the speeds of the compressor stages to maintain a predetermined source pressure during normal load operation.

[0038] On the other hand, if the volumetric flow rate exceeds a predetermined minimum, i.e., if there is no flow rate or only a small amount of flow rate is removed, the operating state of the compressor system switches from load operation to idling operation. To this end, in the next step, the discharge valve is opened to allow at least a partial release of the volumetric flow rate initially continuing from the second compressor stage. This prevents the pressure at the screw compressor outlet from exceeding the maximum permissible amount. The discharge valve can be, for example, a controlled solenoid valve.

[0039] In a further step, this step is preferably performed substantially simultaneously with or with only a slight delay from opening the exhaust valve, at least reducing the speed of the first compressor stage to a predetermined V1. L This reduces the volumetric flow rate supplied from the first compressor stage to the second compressor stage. Contrary to existing technology, for this purpose, the throttle valve or suction regulator is not closed. Instead, the inlet of the first compressor stage remains fully open. The throttle valve or suction regulator and its actuator can be completely eliminated. Preferably, the reduction in volumetric flow rate supplied from the first compressor stage is solely achieved by reducing the velocity of the first compressor stage to the idle speed V1. L And it happened.

[0040] According to a preferred embodiment, in the next step, the speed of the second compressor stage is further reduced to the idling speed V2. L Preferably, in each case, the speeds of the two compressor stages decrease to the idling speed V1 in essentially parallel operation. L or V2 L .

[0041] The idling speed V1 of the first compressor stage L (Low Pressure – LP) Selected to match the idling speed V2 of the second compressor stage. L (High Pressure – HP) coordination ensures that the discharge temperature of the medium at the second stage is not lower than the inlet temperature at that stage. Such accidental operating conditions can occur when the pressure ratio at the second compressor stage is less than 0.6. Therefore, the idling speed should be selected to ensure that the second stage does not operate as an "expander" and thus the medium temperature does not drop. Otherwise, undesirable condensation may occur in the compressor. Additionally, when selecting the idling speed, it should be ensured that the second compressor stage is not driven via the medium supplied from the first compressor stage, as otherwise the second stage's drive will become generator operation, which can lead to damage to the frequency converter controlling it.

[0042] The minimum idle speed is also determined by the acceptable delay when re-entering the load state. The shorter this return time, the higher the selectable idle speed.

[0043] Preferably, the speed ratio between the second stage and the first stage during idling is in the range of 2 to 3, specifically preferably around 2.5. During this process, the pressure ratio of the first stage is approximately 1.5, and the pressure ratio of the second stage is in the range of 0.6 to 0.75. Preferably, the idling speed V2 of the second compressor stage... L It is approximately 1 / 2 to 1 / 4 of the load speed of this stage. Preferably, the idling speed V1 of the first compressor stage is... L It is about 1 / 5 to 1 / 8 of the load speed of this level.

[0044] Therefore, a beneficial effect of this control method is that both compressor stages can operate at significantly reduced speeds while idling. This reduces energy consumption and wear. Additionally, the temperature of the compressed medium decreases at the outlet of the respective compressor stage, which has a positive impact on the total amount of heat accumulated in the compressor system. However, under new demands on volumetric flow rate, the screw compressor can very quickly return to load operation by increasing the speed of the compressor stage again. Attached Figure Description

[0045] Further beneficial effects and details of the present invention will arise from the following description of preferred embodiments with reference to the accompanying drawings. The drawings illustrate the following: Figure 1 Showing a partial open view of the innovative compressor system; Figure 2 A partial cross-sectional view of a compressor system showing the indicated cooling airflow is shown. Figure 3 A longitudinal section of the pulsation damper that forms part of the system is shown; Figure 4 Showing according to Figure 3 A cross-section of the pulsation damper; Figure 5 A simplified representation of the operating parameters in a screw compressor with two compressor stages during load operation is shown; Figure 6 This shows a simplified representation of the operating parameters of a screw compressor during idling operation. Detailed Implementation

[0046] Figure 1 An inventive compressor system 01 is shown in a partially opened perspective view. The compressor system 01 has a closable system housing 02, the sidewalls 03 of which are only partially shown. The system housing 02 includes a bottom 04 and a door 05, wherein the door 05 allows access to internal system components 06. System components 06 generate heat during operation of the compressor system and include at least one compressor stage for compressing a gaseous medium. The door 05 has a first portion of a cooling air passage 07, which has an inlet opening 08 at the top and an outlet opening 09 at the bottom. A passage 11 is arranged in the bottom 04, which connects to the outlet opening 09 when the door 05 is closed to allow cooling air to flow into the bottom 04. Thus, the cooling air passage 07 consists of a portion extending in the door, a portion in the bottom, and a portion within the system housing, wherein the cooling air passage 07 is formed, for example, by an air-conducting element.

[0047] Figure 2The compressor system 01 is shown in an open view, with some system components not shown. It is thus apparent that an air-water cooler 12 is arranged at the upper third of the system housing, positioned above the heat-generating system component 06. Several upper air conduction elements 13 are arranged within the system housing, which conduct rising hot air (indicated by warm air arrow 14) to the air-water cooler 12.

[0048] A blower 15 is arranged above the air-water cooler 12 to generate a circulating cooling airflow. The blower draws in warm air passing through the air-water cooler and blows this cool air, which serves as the cooling airflow 16, towards the inlet opening 08 of the cooling air passage 07. The cooling airflow 16 is conducted downstream in the cooling air passage 07 and exits through the outlet opening 09 to reach the bottom 04 via the passage 11. A lower air conduction element 17 is arranged in the bottom 04, and if necessary, a lower air conduction element 17 may also be arranged in the lower portion of the system housing to conduct the cooling airflow to the system component 06 to be cooled.

[0049] Figure 3 A simplified longitudinal sectional view of a pulsation damper 100, a system component of the compressor system previously described, is shown. Figure 4 A cross-section of the pulsation damper is shown. The acoustic damper 100 in this example has a substantially cylindrical damper housing 101, which has an absorption element receiving area 102, a front plate 103 sealing the damper housing on the front side, and a flange 104 axially opposite to the front plate. The front plate 103 has a centrally located medium inlet 106 through which a gaseous medium flow 107 compressed by a compressor is supplied, specifically, compressed air.

[0050] A plurality of sleeve-shaped absorption elements 108 are arranged in the absorption element receiving area 102. In this example, a front absorption element 108a, a center absorption element 108b, and a final absorption element 108c are shown in relation to the flow. The three absorption elements are telescopically interlocked and have substantially the same length in the axial direction. All absorption elements are composed of sound-absorbing material, wherein the specific properties of the material can be selected differently among the individual absorption elements.

[0051] The medium flow inlet 106 flows into the centrally located inlet region of the front absorber element 108a, causing the medium flow to initially flow inside the front absorber element 108a and be damped by its material. The interior of the front absorber element 108a can be hollow or filled with a gas-permeable material, where flow resistance will remain low. An outlet region is provided at the end of the front absorber element 108a that avoids the front plate 103, allowing the medium flow to exit from the front absorber element 108a. The medium flow flows into the inlet region of the central absorber element 108b in the first annular transition region 110, where there is a reversal of direction in the medium flow 107. The central absorber element 108b annularly surrounds the front absorber element 108a for flow purposes, wherein a central pin 111 provided on the central absorber element 108b serves as a fixing device for the front absorber element 108a. The medium flow 107 now flows through the first cylindrical flow chamber 112, which extends axially between the front absorption element 108a and the central absorption element 108b.

[0052] At the end of the central absorber element 108b pointing towards the front plate 103, the medium flows out of the first cylindrical flow chamber 112 via the outlet region and flows into the inlet region of the rear absorber element 108c in the second annular transition region 113. The medium flow 107 now flows through the second cylindrical flow chamber 114, which extends axially between the central absorber element 108b and the rear absorber element 108c. The flow direction in the second flow chamber 114 is axially opposite to the flow direction in the first flow chamber 112.

[0053] At the end of the rear absorber element 108c that avoids the front plate 103 in terms of flow, the medium flow 107 exits the absorber element receiving region 102 via the outlet region of the rear absorber element 108c in terms of flow, and then flows to the downstream unit of the compressor through the medium flow outlet 116 in the flange 104. It is evident from the figure that in each case the cross-section available for the medium flow increases significantly in the variation region, and ultimately the cross-section at the medium flow outlet 116 is significantly larger than the cross-section at the medium flow inlet 106.

[0054] It is also evident from the figure that each of the three absorbing elements 108 has a number of resonator chambers 117a, 117b or 117c in their walls.

[0055] Figure 5 The schematic structure of the compressor system is shown, which serves as a system component of the twin-screw compressor 200. In addition to the individual components of the twin-screw compressor, conventional parameters are described, as these parameters occur during load operation when compressed air is discharged at a volumetric flow rate higher than a predetermined minimum but not exceeding the system-specified maximum.

[0056] The first compressor stage 201 has a first direct drive unit 202, the speed of which is controlled. The inlet of the first compressor stage 201 is directly connected to an intake support 203 without the insertion of an intake regulator. An ambient atmosphere exists at the intake support, having a pressure of 1.0 bar at a temperature, for example, 20°C, where ambient air is drawn in via the inlet of the first compressor stage 201. Therefore, a pressure of 1.0 bar exists at the inlet of the first compressor stage 201.

[0057] The first compressor stage 201, for example, operates at 15,500 min. -1 The compressor operates at a speed to compress air. A pressure of 3.2 bar is then present at the outlet of the first compressor stage 201, resulting in a compression ratio of 3.2 for the first compressor stage under load. Due to compression, the temperature of the medium (compressed air) increases to 170°C. The compressed air is conducted from the outlet of the first compressor stage 201 to the inlet of the second compressor stage 206 via an intercooler 204, the second compressor stage 206 having a speed-controlled second direct drive unit 207. The heat accumulated at the intercooler 204 must be dissipated from the compressor system. The air circulating in the system housing 02 is cooled by an air-water cooler 12. If the intercooler has a water cooler, the cooling water flowing in the air-water cooler can be conducted through the intercooler 204 via parallel branches or series connections. After the intercooler 204, at the inlet of the second compressor stage 206, the compressed air has a temperature of 30°C and an additional pressure of 3.2 bar. Under load, the second compressor stage 206 operates at, for example, 22,000 min... -1 The compressor operates at a speed that allows for further compression. Therefore, the compressed air has a pressure of 10.2 bar and a temperature of 180°C at the outlet of the second compressor stage 206. Thus, the second compressor stage 206 also has a compression ratio of approximately 3.2. The compressed air is conducted from the outlet of the second compressor stage 206 through the aftercooler 208 and cooled to approximately 35°C in the aftercooler 208. The aftercooler 208 can also be integrated into a cooling water circuit that supplies the air-water cooler 12 and / or the intercooler 204. Finally, an exhaust valve 209 is arranged at the outlet of the twin-screw compressor 200, which is controlled by a control unit (not shown).

[0058] The twin-screw compressor 200 described by example shows a power loss of 150 kW at the maximum speed of the direct drive sections 202 and 207, and supplies compressed air with a maximum pressure of 12 bar and a minimum pressure of 6 bar. The speed ratio between the compressor stages is approximately 1.4 during load operation.

[0059] Figure 6The twin-screw compressor 200 is shown in idling operation (i.e., when there is essentially no compressed air being removed). The conventional parameters are described again along with the components of the twin-screw compressor, as they occur during idling operation. To enter idling operation, the exhaust valve is opened, and the speeds of both compressor stages are reduced. The inlet of the first compressor stage 201 is directly connected to the intake support 203 without the insertion of an intake regulator, where ambient air is present, having a pressure of 1.0 bar at a temperature of 20°C, wherein additional ambient air (even in a reduced amount) is drawn in via the inlet of the first compressor stage 201. Therefore, a constant pressure of 1.0 bar exists at the inlet of the first compressor stage 201.

[0060] The first compressor stage 201 is now in V1. L =2,500 min -1 The compressor operates at an idle speed to compress air. Then, a pressure of 1.5 bar is present at the outlet of the first compressor stage 201, resulting in a compression ratio of 1.5 for the first compressor stage during idle operation. Due to the reduced compression, the temperature of the medium (compressed air) only rises to 90°C. The compressed air is transferred from the outlet of the first compressor stage 201 to the inlet of the second compressor stage 206 via intercooler 204. After intercooler 204, at the inlet of the second compressor stage 206, the compressed air has a temperature of, for example, 30°C and an additional pressure of 1.5 bar (intermediate pressure) during idle operation. Therefore, the cooling capacity necessary for intercooling is reduced during idle operation. During idle operation, the second compressor stage 206 operates at 7,500 min... -1 Idle speed V2 L Operation. The compressed air has a lower pressure of approximately 1.2 bar (compared to the intermediate pressure) and a temperature of 70°C. Therefore, the second compressor stage has a compression ratio (expansion) of approximately 0.8. The compressed air is conducted from the outlet of the second compressor stage 206 through the aftercooler 208 and cooled to approximately 30°C in the aftercooler 208.

[0061] The twin-screw compressor 200 described by example shows a power loss of 7 kW during idling operation and a maximum supply pressure of 1.2 bar. The speed ratio between compressor stages is approximately 3.

[0062] List of reference numerals 01 Compressor System 02 System Housing 03 Sidewall 04 Bottom 05 doors 06 System Components 07 Cooling air passage 08 Entrance opening 09 Exit Opening 10 – 11 access 12 Air-water coolers 13 Upper air conduction element 14 Warm air 15. Blower 16 Cooling airflow 17 Lower air conduction element 100 Pulsation Damper 101 Damper Housing 102 Absorption element receiving area 103 front panel 104 Flange 105 - 106 Medium Flow Inlet 107 Medium Flow 108 Absorption Elements 109 -– 110 First Change Zone 111 Center Sales 112 First Flow Chamber 113 Second Change Region 114 Second Flow Chamber 115 - 116 Medium Flow Outlet 117 Resonator Chamber 200 twin-screw compressor 201 First compressor stage 202 First Direct Drive Unit 203 Inhalation Support 204 Intercooler 205 - 206 Second compressor stage 207 Second Direct Drive Unit 208 Aftercooler 209 Exhaust Valve

Claims

1. A compressor system (01) having a system housing (02) in which: - The system component (06) that generates heat includes at least one compressor stage (201) for compressing the gaseous medium. -Air-water cooler (12); - Blower (15) generates cooling airflow (16); - An air conduction element conducts hot air from the system component (06) to the air-water cooler (12). Its features are, The system is equipped with a cooling air passage (07) having an inlet opening (08) in the upper portion of the system housing (02) and an outlet opening (09) in the lower portion of the system housing (02); an upper air conduction element (13) is provided to conduct the cooling airflow (16) to the inlet opening (08) after flowing through the air-water cooler (12); and a lower air conduction element (17) is provided to conduct the cooling airflow (16) from the outlet opening (09) to the system component (06).

2. The compressor system (01) according to claim 1, characterized in that, The air-water cooler (12) is located above the heat-generating system component (06), and the blower (15) is located above the air-water cooler (12) to draw in the cooling airflow (16) through the air-water cooler (12) and supply the cooling airflow (16) to the inlet opening (08) of the cooling air passage (07).

3. The compressor system (01) according to claim 1 or 2, characterized in that, The cooling air passage (07) extends at least in the portion of the door (05) that seals the system housing (02).

4. The compressor system (01) according to any one of claims 1 to 3, characterized in that, The cooling air passage (07) extends in a portion of the bottom (04) of the system housing (02) and has a plurality of outlet openings in the bottom (04) that allow the cooling air to be released upwards into the system housing (02).

5. The compressor system (01) according to any one of claims 1 to 4, characterized in that, The system housing (02) is hermetically sealed relative to the environment, wherein the compressor stage (201) is connected to an intake support (203) that is open to the environment.

6. The compressor system (01) according to any one of claims 1 to 5, characterized in that, The system component (06) that generates heat includes electronic circuitry.

7. The compressor system (01) according to any one of claims 1 to 6, characterized in that, The air-water cooler (12) can be connected to an external cooling circuit with a heat recovery unit.

8. The compressor system (01) according to any one of claims 1 to 7, characterized in that, The heat-generating system component (06) includes a screw compressor having a first compressor stage (201) and a second compressor stage (206), wherein the first compressor stage (201) compresses the gaseous medium and conducts the gaseous medium to the second compressor stage (206), and the second compressor stage (206) further compresses the gaseous medium. - The first compressor stage (201) and the second compressor stage (206) are driven independently and at adjustable speeds; - An exhaust valve (209) is present, which opens when the volumetric flow rate removed from the second compressor stage (206) is below a predetermined minimum. Wherein, at least the speed of the first compressor stage (201) is reduced to a predetermined idling speed (V1). L This reduces the volumetric flow rate supplied from the first compressor stage to the second compressor stage.

9. The compressor system (01) according to any one of claims 1 to 8, characterized in that, The heat-generating system component (06) includes a pulsation damper (100) disposed in the system housing (02), the pulsation damper (100) being arranged downstream of the final compressor stage (206) in terms of flow, and the components of the pulsation damper (100) include: - The damper housing (101) extends along the central axis and has a medium inlet (106) and a medium outlet (116). - Multiple sleeve-shaped absorbing elements (108), composed of sound-absorbing material, are concentrically arranged within the damper housing (101), wherein, Each sleeve-shaped absorber element (101) has an inlet region and an outlet region, the inlet region and the outlet region being positioned axially spaced apart from each other. In terms of flow, the inlet region of the foremost absorber element (108a) is connected to the medium flow inlet (106) of the damper housing (101), the outlet region of the foremost absorber element (108a) is connected to the inlet region of the subsequent absorber element (108b), and the outlet region of the last absorber element (108c) is connected to the medium flow outlet (116) of the damper housing (101). Between the respective radially adjacent wall portions of the different absorption elements (108), there are flow chambers (112, 114) for the flow of the medium in various cases.

10. The compressor system (01) according to claim 9, characterized in that, The absorbing element (108) of the pulsation damper (100) is configured to be rotationally symmetric and telescopically engaged, but axially fixed.

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