Compressor device with cooling mechanism and method for operating compressor device

Abstract

To provide a device by which adapted cooling for a compressor device with a cooling device can be simply provided.SOLUTION: A cooling device includes an oil cooler for cooling oil heated by a compressor, at least one compressed gas cooler for cooling gas that has been completely or partially compressed to a compressed gas, and at least one housing cooler for cooling a housing or a part of a housing of the compressor. The oil cooler, the at least one compressed gas cooler, and the at least one housing cooler are each prepared to achieve cooling by a coolant flow consisting of a fluid coolant, in particular water. For the coolant flow of the oil cooler, at least one of the coolant flows of the at least one compressed gas cooler, and at least one of the coolant flows of the at least one housing cooler, individual controllable control means are provided.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a compressor device for compressing a gas to generate a compressed gas, particularly compressed air, and comprising a cooling device. Furthermore, the present invention relates to a method for operating a compressor device comprising a cooling device.

Background Art

[0002] Compressors for compressing a gas to generate a compressed gas are sometimes called compression gas compressors. Thus, they are used to generate a compressed gas, often compressed air. This compressed air, or other compressed gas, is particularly intended for subsequent industrial use. The following description regarding compressed air is equally applicable to other compressed gases.

[0003] Functionally, heat is generated during the generation of compressed air. Both the compressed air and the compressor, particularly its housing, are heated and thus must be cooled. For cooling, a housing cooler for cooling the housing of the compressor or a part thereof can be provided, which is also often called a jacket cooler or is often designed as a jacket cooler. In a jacket cooler, a cooling medium, particularly water, which is sometimes also synonymously called a coolant, can flow through the housing cooler, thereby cooling the housing. Furthermore, a compressed gas cooler can be provided which is arranged in a part of the conduit system for guiding the compressed gas, particularly compressed air. Here, in particular, a heat exchanger can be provided, through which a cooling medium or coolant, particularly water, also flows. During the generation of compressed gas, oil is often required, particularly for lubricating the components of the compressor. Such oil is also heated and can be cooled by an oil cooler, which can in particular comprise a heat exchanger. Through this heat exchanger, a cooling medium or coolant, particularly water, also flows.

[0004] By connecting all of the above-described coolers (it is also possible to provide a plurality of each of the above-described coolers) to the primary cooling circuit, efficient cooling can be achieved. In particular, the cooling mechanisms can be connected completely or partially in parallel, so that one cooler cannot receive the already heated water of the previous cooler as occurs in a series connection.

[0005] By means of the parallel connection, the individual coolers receive their cooling water portions according to the flow resistance of their parallel branches. By appropriate design of these parallel branches or of the coolers themselves, the coolers each receive an appropriate amount of coolant, namely especially water.

[0006] However, it has been found that the cooling demand, and thus the demand for coolant, namely cooling water, can vary. To cope with this, the flow of coolant in the primary circuit can be adapted as appropriate. However, if the changes in coolant demand in the individual coolers are different, the optimal cooling in one cooler can result in over-cooling or under-cooling in another cooler.

[0007] To adapt such non-optimal cooling, corresponding valves can be provided for adaptation, and the valves can be used to set the coolant inflow of each of the individual cooling mechanisms. However, such adaptation can be time-consuming because the installation operator has to make or change the corresponding settings. Also, the results depend on the individual capabilities of the installation operator.

[0008] As a further improvement, individual cooling mechanisms can be provided, with each cooler including its own cooling circuit. However, such a solution is complex and thus not necessarily recommended.

[0009] From Patent Document 1, a cooling mechanism for a compressor that can adapt the amount of cooling fluid in particular is known.

Prior Art Documents

Patent Documents

[0010] [Patent Document 1] WO2022 / 163079A1 [Patent Document 2] German Patent No. 102014019805B3 [Patent Document 3] European Patent Application Publication No. 3399191A1 [Summary of the Invention] [Problems to be Solved by the Invention]

[0011] Therefore, an object of the present invention is to address at least one of the above-described problems. In particular, a solution is proposed that easily provides adapted cooling for a compressor device equipped with a cooling device. At least, an alternative solution to the conventionally known solutions should be proposed. [Means for Solving the Problems]

[0012] According to the present invention, a compressor device according to claim 1 is proposed. That is, a compressor device equipped with a compressor and a cooling device is provided. The compressor, which may also be called a compression gas compressor synonymously, is intended to compress gas to generate compressed gas. In particular, a compressed air compressor for generating compressed air is proposed. This generates compressed gas or compressed air in a basically known manner.

[0013] Furthermore, a cooling device is provided that includes at least one oil cooler, one compressed gas cooler, and one housing cooler. The oil cooler is intended to cool the oil heated by the compressor. The oil can flow from the compressor through a heat exchanger and release its heat to a fluid coolant, particularly water, i.e., cooling water.

[0014] The compression gas cooler(s) (which may be provided in plurality) is / are intended to cool the compression gas. For this purpose, the compression gas flows through this compression gas cooler, where it releases heat to the fluid coolant. It is also contemplated that the compressor may have multiple compression stages, whereby the gas is brought to a first pressure level after the first compression stage, which can also already be regarded as compression gas. However, this compression gas has not yet been compressed to the final pressure level and can therefore be assumed to be partially compressed gas. However, for this partially compressed gas (which may already simply be called compression gas as described above), a compression gas cooler can also be provided, in which case the compression gas cooler can be arranged between two compressor stages. If there are at least two compressor stages, at least one additional compression gas cooler can be newly provided after the second compressor stage, and this compression gas cooler cools the compression gas discharged from the second compressor stage described above.

[0015] The housing cooler, which may be provided in plurality, is intended to cool the compressor housing or a part of the housing. Here, basically, the physical overall configuration of the compressor, or a part thereof, can be regarded as the compressor housing. Therefore, this is not only the housing in the sense of the cover of the compressor, but also the compressor as a physical object.

[0016] Therefore, it is proposed that for these coolers, the oil cooler, at least one compression gas cooler, and at least one housing cooler are each prepared to achieve cooling by means of a coolant flow consisting of a fluid coolant, particularly water. Therefore, each of these coolers has at least one flow channel through which the coolant can flow. Therefore, the coolers described above are, in principle, coolers that use a coolant flow consisting of a fluid coolant for cooling, that is, coolers that are cooled particularly by water or cold water. During operation, the coolant flow flows through each cooler.

[0017] In particular, for the coolant flow of the oil cooler, at least one coolant flow of at least one compression gas cooler, and at least one coolant flow of at least one housing cooler, respective individually controllable control means are provided to control each of the coolant flows individually, and thus it is contemplated that the cooling performance for each of the oil cooler, at least one of the at least one compression gas cooler, and at least one of the at least one housing cooler can be controlled individually. That the control means are controllable means that the control means can be controlled by control or adjustment, not manually. It can also be said that it is automatically controllable. So that the control means can be made controllable, the control means can be provided with, for example, a control input and can receive a control signal via the control input.

[0018] For example, one of the coolers, for example a compression gas cooler, has two or more partial coolers, or is subdivided into two or more partial coolers, for example an intercooler and an aftercooler, and it is also contemplated that both partial coolers can be controlled via respective control means. Thus, for each of the two or more partial coolers, the respective coolant flow is controllable. For this purpose, the partial coolers can be connected in parallel with each other. The individual control of each one coolant flow through each partial cooler can be configured, additionally or exclusively, such that the distribution of the total coolant flow to the partial coolers is controlled.

[0019] For example, two housing coolers, sometimes also called jacket coolers, can be connected in parallel, whereby the coolant flow is distributed to these two housing coolers and only one control means is provided for both housing coolers. This control means controls the housing cooler, and thus each individual housing cooler, or the associated coolant flow individually, as long as the control is carried out independently of the control of the coolant through the oil cooler and the control of the coolant flow through the compression gas cooler.

[0020] Preferably, by connecting these coolers to each other completely or partially in parallel, a primary cooling circuit for all coolers is provided. However, this does not exclude, for example, two coolers that can be configured as jacket coolers, such as two housing coolers, being connected in series. Such two jacket coolers connected in series can also be regarded as a common housing cooler. When two or more partial coolers are connected in parallel to each other, these partial coolers are connected in series in the primary cooling circuit with other coolers or some of them, thereby receiving the entire coolant flow of the primary cooling circuit, and it is considered that they can be controlled both with respect to each other and individually by their parallel connection.

[0021] In any case, it is proposed to provide individual controllability as well, although a common primary cooling circuit can still be used. Thus, each individual control means may be configured as a controllable valve or as a controllable pump, or some individual control means may be configured as controllable valves and other individual control means may be configured as controllable pumps. This makes it possible to always adapt the coolant flow of each cooler, thereby enabling each cooler to operate at its optimum operating point. Thus, each cooler can be operated optimally. For example, if an increase in the cooling demand for an oil cooler occurs, the coolant flow rate of the oil cooler can be increased without increasing the coolant flow rate of the other coolers.

[0022] Conversely, optimal cooling does not necessarily mean being cooled to the lowest possible temperature, and it has been recognized that the ability to release or absorb moisture also depends particularly on the temperature of the compressed gas. Compressed gas, especially compressed air, has a tendency not to absorb much moisture or to release moisture when the cooling is too strong. If this is not desirable, it can be prevented by appropriate cooling control, and if so, it can be promoted. Therefore, the cooling performance of one cooler can also be individually reduced while the cooling performance of other coolers is maintained or optimized. This is considered, for example, when the cooling water volume flow is limited or a specific (minimum) water outlet temperature is required from the entire system.

[0023] Here, it has been particularly recognized that with the proposed individual control, the oil cooler, at least one housing cooler, and furthermore at least one compressed gas cooler, or their coolant flows can be controlled independently of each other. This enables optimal cooling for each cooler, which can also keep the overall required cooling performance to a minimum. Here, when using a common primary cooling circuit, it should be noted that the common coolant flow, i.e., the sum of all the coolant flows of the individual coolers (and thus sometimes also called the total coolant flow), has to be recooled. If the cooling in the cooler is too strong, this will introduce more heat into the total coolant flow or the sum of the coolant flows as a whole, and as a result, the cooler in the primary cooling circuit may have to extract, i.e., recool, more heat from the common coolant flow.

[0024] It is also important that the gap between the compressor housing and the rotor is kept within an optimal range. If the cooling of the housing is too strong, it will lead to size reduction and thus cause contact between the rotor and the housing, thereby permanently increasing the gap. If the cooling of the housing is too little, an unnecessarily large gap will occur between the rotor and the housing, which will cause internal backflow of the already compressed gas.

[0025] Also, it is important to cool the compressed air after the last compressor stage to an optimal value. If the cooling is too little, there is a risk of component damage or, in some cases, the compressed air drying may not function properly.

[0026] For an oil cooler, it is important that the oil viscosity is kept within an optimal range as much as possible depending on the oil temperature. If the oil is too cold, the power consumption increases, and if the oil is too hot, the wear increases.

[0027] Therefore, the proposed solution can also reduce the recooling required overall. However, lower power consumption and an optimal compressed air outlet temperature are often more important.

[0028] In many cases, a high temperature in the total coolant flow or combined coolant flow is desirable. Therefore, as much heat as possible should be transferred to the heating water, which can be interlocked with or used for the total coolant flow or combined coolant flow, for example, saving on heating fuel costs. However, for this purpose, the temperature level must be appropriately increased so that the cooling water can be used for heating purposes, which can be disadvantageous for the cooling of the compressor but beneficial if there is a corresponding heat demand. This can also reduce the investment costs.

[0029] In particular, it is contemplated that the individual control means are provided or controlled for non - manual control and / or automatic control and / or control by a control program.

[0030] According to one aspect, it is proposed that an oil cooler, at least one compression gas cooler (at least one of a plurality if there are a plurality), and at least one housing cooler (at least one of a plurality if there are a plurality) are connected to a common coolant circuit, in particular a primary coolant circuit, in particular in a fully or partially parallel connection.

[0031] The advantages related to this have already been described. Therefore, it is still possible to continue to provide only one common coolant circuit, thereby enabling the use of a single aftercooler. However, what is particularly important here is the common heat dissipation to enable the most complete heat utilization possible. Nevertheless, the possibility of individual control of the individual coolers is provided. Therefore, despite the common coolant circuit, the individual control of the individual coolers described above is possible.

[0032] This has the advantage, especially when improving existing systems and in some cases also existing infrastructure, whether during planning or retrofitting, that it is only necessary to supplement the individual coolers with individual control means. This of course does not rule out the possibility of also making savings in the common coolant circuit, such as a smaller design or sizing of the aftercooler for the common coolant circuit or primary coolant circuit, after or together with such optimization.

[0033] According to one aspect, it is proposed that the compressor comprises a plurality of compression stages and at least one compressed gas cooler comprises an intercooler and an aftercooler. Here, the intercooler is arranged between the first compression stage and the second compression stage and cools the gas that has been partially compressed into a compressed gas, i.e., the compressed gas that has not yet reached the maximum pressure level contemplated for the entire system. Further, an aftercooler is provided at the outlet of the compressor, i.e., the outlet of the last compression stage. Therefore, in the case of two compression stages, the aftercooler is provided after the second compression stage. There, the aftercooler cools the compressed gas having the final pressure level of the compressed gas, i.e., the pressure level after the second compression stage. In particular, it is contemplated here that the intercooler and the aftercooler each have individually controllable control means, or at least one control means is assigned to each of the intercooler and the aftercooler. Thereby, the intercooler and the aftercooler can also be individually controlled respectively. They can also be connected in parallel with each other and / or with the remaining coolers.

[0034] According to one aspect, it is proposed that the control means each comprise a controllable valve and / or a controllable pump.

[0035] With a controllable valve, the control means can be easily realized. The controllable valves, which apply to all control means, can be centrally controlled by a control function to achieve overall control. The controllable valve requires only minimal control energy and is thus cost-effective both in terms of purchase and operation. By throttling the valve, a higher pump output is required, which is then throttled again. In terms of the energy cost of water circulation, individual pumps can be more economical.

[0036] One advantage of valves is that they close in a sealed manner. This can be advantageous when multiple compressors are operated in a common cooling system, although not all compressors operate simultaneously all the time. When at rest, the valve can be closed so that there is no unnecessary flow.

[0037] Since a controllable pump is an active component, it can be more complex than a controllable valve, but it can achieve better control results. In particular, when a controllable pump is used, the coolant flow controlled thereby depends little or not at all on the total coolant flow present. If all individual control means are configured as controllable pumps, the pump for pumping the total coolant flow may also become unnecessary. However, although it is often advantageous to define a single variant in many cases, combinations are also possible.

[0038] According to one aspect, it is proposed that at least one housing cooler comprises at least one jacket cooler, the jacket cooler having in particular two partial jacket coolers connected in series for cooling each one compressor stage, the compressor stages being prepared to use the same coolant flow for cooling and to control the coolant flow by the same control means.

[0039] Thus, in such a jacket cooler, a medium line is provided in the jacket area of the compressor. As a result, an appropriate coolant flow passes through the compressor, thereby cooling the compressor.

[0040] In the proposed series-connected partial jacket cooler, in particular, one partial jacket cooler can cool the jacket of the compressor of the first compression stage, and the second partial jacket cooler can cool the second compression stage. In a preferred form, the cooler water first flows through the second stage. This is because here, the housing temperature, and thus the housing size, in particular the size of the gap, acts more strongly against the countercurrent. That is, it has been recognized that it is beneficial to first flow water through the second stage due to the geometry of the compressor.

[0041] With series connection, even if the coolant volume flow rate for jacket cooling is the same, a higher flow rate can achieve better heat transfer, and thus better cooling effect, than in the case of parallel connection.

[0042] Preferably, the jacket cooling mechanism receives a very large amount of cooling water so that the preheating of the coolant at the second stage does not affect the first stage so strongly.

[0043] Here, it is beneficial to consider these two partial jacket coolers together as one jacket cooler, and thus one housing cooler, and to control only one control means.

[0044] Here, it is also based on the recognition that the two compression stages are basically loaded equally strongly and can thus be controlled together. Therefore, it has been recognized that synchronous connection and integrated control of these two jacket coolers for the two compression stages are suitable. In particular, it has been recognized that individual control is not always necessarily advantageous.

[0045] According to one aspect, a common control device is provided for the coordinated control of the coolant flow. In particular, it is proposed that a common control device is provided and connected to the control means for controlling the control means.

[0046] Thereby, not only can the individual coolers themselves be well controlled, but also the mutual coordination of the coolers can be achieved, and in particular, the overall cooling concept can be achieved. Here, also, when using a common aftercooler for all coolers and / or when using a common primary cooling circuit for all coolers, it is also recognized that the coordinated control of the coolant flow makes it further possible to take into account the requirements in or by the aftercooler or the requirements in or by the primary cooling circuit. Therefore, for example, the temperature in the aftercooler and / or the temperature at the outlet of the common primary cooling circuit can be taken into account and even adjusted.

[0047] The common control device can control all the control means and can be connected to them for this purpose. Such a connection particularly relates to a data-technical connection. The connection can be a wired connection, which is often suitable. This is because in many cases, all the above-mentioned coolers are located close to each other geographically. If necessary, some elements, such as an aftercooler, may be further apart, especially when provided in an embodiment as a cooling tower. Even in that case, a wired communication, and thus a wired connection, can be provided between the common control device and the control means, but a cordless connection, especially a wireless connection, is also considered.

[0048] The common control device can be particularly prepared to control the control means by receiving actual values from the control means and / or transmitting target values to the control means. Preferably, the control device can be connected to further sensors, especially temperature sensors, but also to humidity sensors, which can be provided for capturing the humidity of compressed air or compressed gas. Other characteristics of the compressed gas can also be captured and transmitted to the common control device for further consideration.

[0049] Furthermore, the common control device can also be connected, for example, to a primary cooling circuit, i.e., in particular, to control means for controlling the flow in the primary cooling circuit. For example, further control tasks for a common additional or secondary cooling circuit are also considered if such a circuit is provided.

[0050] Thus, comprehensive control by the common control device, and thus the realization of an overall concept, is possible without the need for a high-level equipment configuration. In particular, the control means can be provided as a controllable valve, in which case only control commands from the common control device are required. Such a solution provides comprehensive controllability and at the same time requires only a small equipment configuration. The same applies when one or more of the control means are provided as pumps. Here too, although these pumps are necessary, they do not result in a high overall equipment cost and can be easily controlled by the common control device.

[0051] Overall, it is possible to achieve an optimal cooling result for the entire compressor device. Here, it is repeated that the optimal cooling result does not mean maximum cooling, but rather an optimal cooling result taking into account the effort expended. For example, a compressor with two compression stages can be provided, and in particular, an intercooler and an aftercooler can be provided. The desired temperature of the final compressed gas can be achieved by strong cooling of the aftercooler and weak cooling of the intercooler, or vice versa.

[0052] In particular, it has been recognized as advantageous to intentionally cool the intercooler and the aftercooler in different ways. In particular, for this purpose, individually controllable control means have been proposed.

[0053] In particular, it is recognized that by cooling the compressed air in the aftercooler only to the required strength, it is possible to achieve the most optimal cooling possible, or to promote such cooling, in particular, to achieve a sufficient pressure dew point, where the compressed air is as warm as possible, or within an acceptable range, but at the same time, to cool the compressed air as strongly as possible in the intercooler. This is because this will reduce the driving performance of the compressor.

[0054] The housing temperature may also affect the compressed air temperature, and the compressed air temperature may also affect the housing temperature. For example, the following control correlations have been recognized. With good intermediate cooling, the outlet temperature from the first compressor stage can also be reduced. That is, when the temperature between the compressor stages is low, the intermediate pressure also decreases there, which in turn reduces the pressure ratio of the first compressor stage, and it has been recognized that this may result in a lower temperature at the outlet of the first compressor stage.

[0055] At least the cooling of the partially compressed compressed air (or generally compressed gas) may also act on the housing temperature, and in particular, may also act on the rotor temperature of at least the second compressor stage through which this cooled partially compressed compressed air is still flowing.

[0056] Therefore, ultimately, all cooling temperatures affect each other and may jointly affect the overall cooling result of the compressor device. All of these can be coordinated by a common control device. At this time, an optimal compressed gas product can be achieved. This may also affect the power consumption of the compressor.

[0057] This can also achieve a high temperature level when the total coolant flow or the combined coolant flow exits, thereby enabling further utilization of the heat.

[0058] According to one aspect, it is proposed that the compressor is a dry compression compressor and / or a screw compressor. A screw compressor is a compressor configured to compress a gas, particularly air to be compressed, by the movement of two meshing screws. Thereby, in particular, a continuous compression process can also be executed.

[0059] In a dry compression compressor that can also be configured as a screw compressor, oil is not used for the compression process, and in particular, oil is not injected into the compressed gas or the gas that has been compressed and has become the compressed gas. It has been recognized that such a dry compression compressor can be heated more strongly than other compressors, especially because the cooling effect of the injected oil is eliminated. The fields of application are, for example, fields where oil-free compressed air is required, such as the pharmaceutical industry, the food industry, cleanroom applications, etc. Here, the compressed air must not be contaminated with oil. Therefore, such applications can be cooled well without the risk of such contamination by the proposed solution. Therefore, the concept referred to according to this embodiment and any other embodiment is proposed especially for such a dry compression compressor. In particular, the proposed cooling concept can expand the range of use of the dry compression compressor. In particular, the power consumption of the compressor can be reduced. A higher water outlet temperature can be achieved in the total coolant flow, and thus the resulting waste heat can be better utilized.

[0060] According to one aspect, it is proposed to provide at least one or two additional compression gas coolers, which are arranged behind the compressor with respect to the flow direction of the compressed gas and further cool the compressed gas there. For this purpose, it is proposed that at least one additional compression gas cooler, or two or more additional compression gas coolers, be connected to the same primary cooling circuit as at least one of the coolers already mentioned, i.e., one or more compression gas coolers and / or one or more housing coolers and / or oil coolers. Thereby, further cooling of the compressed gas can be carried out, and by using these additional compression gas coolers in the same primary cooling circuit, well-distributed cooling for the compressed gas can be achieved without requiring high equipment costs.

[0061] By means of the additional compression gas cooler, it is possible for other heat exchangers to be cooled at a higher level in a primary cooling system, here for example using heating water. It has been recognized that this can be beneficial for operating the primary water system at a higher temperature so that a large amount of heat can be utilized, but at the same time to produce very dry and / or cold compressed air.

[0062] It is here particularly emphasized that such use of a number of compression gas coolers is only made possible, at least significantly improved, by the proposed control of the individual coolant flows by the control means. Without such individual control means for each compression gas cooler, there is a risk that an unnecessarily large amount of cooling water may flow through the heat exchanger. Manual settings have to take into account the worst-case scenario, for example the maximum output in midsummer. In that case, there is a risk that the compressed air is cooled much more strongly than necessary. Thereby, the operating volumetric flow rate decreases, and thus, in many applications, more compressed air will be consumed.

[0063] Accordingly, in each case, each compression gas cooler, i.e. each additional compression gas cooler, is intended to use a coolant flow that is controlled by its own individual control means. Accordingly, the individual control means control the corresponding coolant flow. In other words, if there are four compression gas coolers, four control means are also provided, i.e. one for each compression gas cooler. These can also be coordinated and controlled by a common control device.

[0064] Additionally or alternatively, it is contemplated that at least one or more additional compression gas coolers are connected to a second medium cooling circuit, sometimes referred to as a secondary cooling circuit. This secondary cooling circuit can operate separately or, in particular, can be coupled to the primary cooling circuit via a heat exchanger.

[0065] Thereby, the supplementation of this one or more additional compression gas coolers can be easily carried out. These can be supplemented and controlled via their own medium cooling circuit, i.e. the second medium cooling circuit, i.e. the secondary cooling circuit. Via the secondary cooling circuit, heat can be dissipated from the primary cooling circuit by means of a heat exchanger, if necessary. Accordingly, the inlet temperature to the primary cooling circuit can be reduced, which results in better cooling and lower power consumption. However, at the same time, the waste heat available is significantly reduced. The second medium cooling circuit is sometimes referred to as the secondary cooling circuit. Accordingly, such a secondary cooling circuit can be provided to cool the primary cooling circuit and, furthermore, to cool the additional compression gas coolers described above, i.e. to supply them with coolant. Thereby, this secondary cooling circuit has a dual function.

[0066] According to one aspect, it is proposed that an oil cooler, at least one compression gas cooler, and / or at least one housing cooler each have a heat exchanger or are configured as a heat exchanger and are prepared such that the respective coolant flows are controlled by respective control means as coolant flows passing through the respective heat exchangers.

[0067] Thus, in particular when using heat exchangers (considered for one, several, or all of the coolers described above), it is clear that the control means controls the flow through each heat exchanger respectively. Thus, thereby, the heat exchanger can be controlled and thereby the cooling performance of each cooler can be controlled.

[0068] According to one aspect, it is proposed that a compressor device, in particular a cooling device, is prepared to control the coolant flows individually according to temperature. The preparation of the compressor device or the cooling device can in particular consist in providing corresponding temperature sensors and providing corresponding control algorithms. In particular, a common control device can be connected to the corresponding temperature sensors, thereby enabling the reception of temperature values from the temperature sensors. The corresponding control functions, in particular the corresponding control programs, can be implemented on the common control device, and this control program gives or is prepared to give at least one control command for issuing to each control means according to one or more received temperature signals.

[0069] Each coolant flow can be controlled by the control means, and the control means can receive the corresponding control commands. The control commands can be created according to at least one temperature value by the above-mentioned control function.

[0070] In particular, it is proposed that the control is performed according to at least one temperature from a list including the following temperatures: - The oil temperature of the oil heated in particular by the compressor, - The compressed gas temperature, - The jacket temperature of the coolant flowing through the housing jacket of the compressor, - The temperature of the coolant, - The oil inlet temperature as the temperature of the oil flowing into the oil cooler, - The aftercooler gas outlet temperature as the temperature of the compressed gas flowing out of one or the above aftercoolers, - The intercooler gas outlet temperature as the temperature of the compressed gas flowing out of one or the above intercooler, - The intercooler coolant outlet temperature as the temperature of the coolant flowing out of the intercooler, - The aftercooler coolant outlet temperature as the temperature of the coolant flowing out of the aftercooler, - The jacket cooler coolant outlet temperature as the temperature of the coolant flowing out of one or the above jacket cooling mechanism, - The gas or coolant outlet temperature as the temperature of the compressed gas or the flowing-out coolant flowing out of at least one heat exchanger respectively, and - The compressor gas outlet temperature as the temperature from the compressed gas flowing out of the compressor stage and / or the compressor and / or the compressor device.

[0071] In particular, it is contemplated that each temperature is measured by a sensor configuration. This enables automatic processing and consideration of the temperature.

[0072] Therefore, the oil temperature is the temperature of the oil heated by the compressor. Such oil can be used particularly as a lubricant in the compressor and is heated by the operation of the compressor. Cooling control according to the temperature enables adjustment of the oil temperature accordingly, thereby not only ensuring good cooling but also avoiding the situation where the cooling of the oil becomes too strong. It is also recognized that the oil temperature affects the viscosity, so oil that is too cold is not necessarily desirable. Here, this temperature adjustment of the oil of the compressor, which is sometimes simply called compressor oil, can be easily realized by the proposed control means.

[0073] Similarly, the control can be carried out in response to the compressed gas temperature, i.e., the temperature of the compressed gas, particularly compressed air. Thus, the compressed gas temperature can also be controlled thereby. Here, it is particularly recognized that the compressed gas must not become too hot, and for this purpose cooling is provided, but the compressed gas must not become too cold either.

[0074] The jacket temperature of the coolant flowing through the compressor housing jacket also provides information regarding the cooling achieved by the compressor. The measurement can be carried out directly within the housing, but it is not necessarily so. The measurement is typically carried out at the outlet or at a higher position outside the housing. In any case, the jacket temperature of the coolant can provide good information regarding the overall temperature of the compressor and is thus not limited to the point temperature at a specific measurement point within the compressor.

[0075] Generally, the temperature of the coolant can also be recorded at various locations. The temperature can provide information regarding the cooling effect of each cooler to which it belongs. In particular, here, the temperature of the coolant after flowing out of each cooler can be used to evaluate the cooling performance and / or temperature at each cooler.

[0076] Additionally or alternatively, the temperature of the coolant before flowing into the cooler can also be used. Particularly advantageously, the difference between the inlet temperature and the outlet temperature of the coolant of the cooler is used, from which the cooling performance of the cooler can be derived.

[0077] Advantageously, the oil inlet temperature, which is the temperature of the oil flowing into the oil cooler, can be taken into account, thereby controlling the coolant flow. If the oil inlet temperature is very low, less coolant flow may be sufficient or no coolant flow may be provided at all, and in other cases, a higher coolant flow rate may be beneficial. The optimal oil temperature may depend on various factors, such as the compressor rotational speed and the type of oil used. In a compressor with adjustable rotational speed, during operation at the current rotational speed, the optimal oil temperature may continuously vary slightly. It has been recognized that the proposed solution can take all these into account, especially by considering the oil temperature.

[0078] The aftercooler gas outlet temperature is the temperature of the compressed gas flowing out of the aftercooler. This temperature provides information on how well the aftercooler was able to cool the compressed gas. In particular, if the aftercooler gas outlet temperature is too high, especially if it is too high for the next component or process, the coolant flow rate through the aftercooler can be increased. In any case, it is proposed to control or adjust the coolant flow through the aftercooler according to the aftercooler gas outlet temperature.

[0079] The intercooler gas outlet temperature represents the temperature of the compressed gas flowing out of the intercooler. This allows the cooling result of the intercooler to be captured. In particular, it is proposed that the cooling water flow through the intercooler be controlled according to the intercooler gas outlet temperature.

[0080] The intercooler coolant outlet temperature is the temperature of the coolant at the outlet of the intercooler. In particular, it has been proposed to control the coolant flow through the intercooler according to the intercooler coolant outlet temperature. In particular, when the intercooler coolant outlet temperature decreases, it has been proposed to reduce the coolant flow rate of the intercooler. Here, in particular, when the intercooler coolant outlet temperature is low, it has been recognized that the coolant in the intercooler did not absorb enough heat, and thus the flow rate through the intercooler was too fast. Therefore, the coolant flow rate can be reduced.

[0081] The same applies substantially to the aftercooler coolant outlet temperature, which represents the temperature of the coolant flowing out of the aftercooler. Here too, it has been proposed to control the coolant flow through the aftercooler according to the aftercooler coolant outlet temperature. Preferably, the coolant flow through the aftercooler is adjusted according to the gas outlet temperature from the aftercooler.

[0082] The jacket cooler coolant outlet temperature represents the temperature of the coolant flowing out of the jacket cooler. Here too, preferably, the coolant flow through the jacket cooler is controlled according to the jacket cooler coolant outlet temperature. The lower the jacket cooler coolant outlet temperature, the less heat energy is absorbed from the compressor per unit volume passing through, which indicates that the coolant flow rate is too high.

[0083] It is also proposed to take into account and control the gas or coolant outlet temperature accordingly. The gas outlet temperature is the temperature of the compressed gas flowing out of the heat exchanger. The coolant outlet temperature is the temperature of the coolant flowing out of at least one heat exchanger. In both cases, the result of the heat exchanger can be evaluated by the corresponding temperature. If the gas outlet temperature from the heat exchanger is high, it can be assumed that the cooling by the heat exchanger is low. If the increase in the coolant temperature that can be measured taking into account the coolant inlet temperature with respect to the coolant outlet temperature is low, it can be assumed that the residence time of the coolant in the heat exchanger is too short and can at least be extended, or in other words, the volume flow rate of the coolant passing through the heat exchanger is too high or unnecessarily high and can in some cases be decreased or throttled.

[0084] It is particularly advantageous to take into account the gas outlet temperature and the coolant outlet temperature of each heat exchanger together. When the gas outlet temperature is low, or when the gas outlet temperature is only slightly higher than the coolant inlet temperature of each heat exchanger, a good cooling result is obtained. At the same time, when the coolant outlet temperature is also low, it can be deduced that the cooling of the compressed gas passing through the heat exchanger can be achieved with a smaller coolant flow rate. In particular, for absolute evaluation, it is proposed to compare the target value with the actual value. However, when the gas outlet temperature is high, especially higher than the corresponding target value, even if the coolant outlet temperature is already low, it may be necessary to increase the coolant flow rate. When the gas outlet temperature is high and the coolant outlet temperature is also high, it can be concluded that the cooling is poor, and at this time, it can be improved by increasing the coolant flow rate. This is because in this case, it can be concluded from the high coolant outlet temperature that the residence time of the coolant in the heat exchanger is too long. In this case, the coolant flow rate can be increased.

[0085] The compressor gas outlet temperature is the temperature of the compressed gas flowing out of the compressor stage of the compressor. This can represent the compressed gas flowing out of the compressor device. Quite generally, it has been recognized that the compressor gas outlet temperature can be used to set the coolant flow accordingly. When this temperature is high, it may be beneficial to increase the coolant flow rate through the relevant compressor stages through which the compressor gas outlet temperature is high. Here, in particular, when the corresponding compressor gas outlet temperature is high there, increasing the coolant flow rate through the corresponding jacket cooler of the relevant compressor stage is considered.

[0086] However, another consideration is also taken into account. The final compression temperature mainly depends on the respective pressure ratios. Furthermore, the rotational speed and the stage condition also have a significant influence.

[0087] Intermediate cooling can also have a significant impact on both the downstream and upstream stages. It is proposed to attempt to optimally cool the jacket cooling mechanism in the long term. This can mean that the jacket cooling mechanism is kept at the same temperature throughout the year. Even if the jacket cooling mechanism is better cooled in winter, this has only a small advantage, and in summer, the cooling deteriorates more, so that the advantage is offset by a larger gap and more reverse flow. The coolant outlet temperature of the cooling circuit is the temperature of the coolant at the outlet from the primary circuit and / or the secondary circuit. At this temperature, basically, the heat absorption of all coolers connected to this primary cooling circuit or secondary cooling circuit can be read as a cumulative result. When the coolant outlet temperature of the cooling circuit is high, it may be beneficial to control the corresponding aftercooler to enhance the cooling performance. Influencing the total coolant flow rate through the primary cooling circuit or the secondary cooling circuit, in particular, setting such a common coolant flow rate higher as the coolant outlet temperature of the cooling circuit becomes higher, is also taken into consideration.

[0088] Accordingly, in particular, the coolant outlet temperature can be adjusted to a desired value. The desired value regarding the coolant outlet temperature can be selected so that the operation proceeds as efficiently as possible. This can mean, for example, that in the case of fresh water cooling, less cooling water is used, or that the specified discharge temperature in, for example, so-called injection wells or rivers is complied with, or that the temperature is adapted for the optimization of the cooling tower. In many cases, a high coolant outlet temperature is also desired in order to achieve the available temperature levels, i.e., to be able to use the waste heat in other processes such as heating, adsorption cooling, drying processes, feed water preheating, etc.

[0089] In particular, the heating of the coolant can be adjusted to a specific value.

[0090] In particular, it is proposed to take into account not only one of the above-mentioned temperatures, but also a plurality of such temperatures. In particular, at least one temperature is taken into account for each cooler used. Preferably, the temperature at each cooler is captured and evaluated, and the coolant flow is controlled accordingly. For example, if the temperature of all coolant flows is too high, it may be suitable to increase the total coolant flow rate. For example, if only one temperature from the coolant flow of one cooler is high and the temperatures of the coolant flows of other coolers are low at the outlet respectively, non-uniform cooling between the target coolers can be assumed. At this time, as an example for explanation, the coolant flow rate with a high temperature can be increased. According to a further example, the total coolant flow can be limited, or a predetermined water outlet temperature can be specified. In such a case, in order to keep the mixed total outlet temperature constant, it is proposed not only to increase the coolant flow rate through one cooler, but also to decrease the coolant flow rate through another cooler at the same time.

[0091] In any case, it is proposed to perform control in response to at least one of the above-mentioned temperatures. In particular, it is proposed to take into account some of these temperatures, and in particular, to control at least one coolant flow or the total coolant flow in response to some of the above-mentioned temperatures, in particular in response to two, three, four, five, or six or more of the above-mentioned temperatures. For this purpose, in particular, a common control device can be used.

[0092] According to one aspect, it is proposed that the compressor device be prepared such that at least one coolant flow is controlled in response to the pressure dew point of the compressed gas. In particular, for this purpose, the pressure dew point is measured using a sensor configuration and can be used for further processing in the control. Here, in particular, it has been recognized that thereby the moisture absorption of the compressed gas can be controlled. When the compressed gas, especially compressed air, is cooled below the pressure dew point, moisture may condense, which may be undesirable, but it can also be intentionally controlled to reach the pressure dew point. According to one form, the cooling device, in particular one, a plurality, or all of the coolant flows, is controlled such that the compressed gas is not cooled below its pressure dew point, thereby avoiding condensation of moisture from the compressed gas, especially compressed air.

[0093] According to another preferred form, it is proposed that the compressed gas be cooled until the dryer connected downstream reaches the desired dew point or, for example, slightly falls short by 1 to 5 Kelvin. This is proposed for the following reasons.

[0094] The compressed gas is cooled to the intensity required to reach the desired dew point before entering the dryer, but not more than necessary. This purpose is that the compressed air after the dryer has the optimum temperature as much as possible, that is, it is as hot as possible but not too hot and is sufficiently dry.

[0095] Furthermore, the available coolant volume flow rate can be distributed such that the total specific power consumption is minimized. This means that, with respect to the generated compressed gas volume flow rate, or compressed gas mass flow rate, at least the power consumption of the compressor, dryer, and cooling system is minimized.

[0096] Such control according to the pressure dew point is particularly proposed when a drying device is present. In this case, the cooling device is controlled such that the temperature of the compressed gas decreases and reaches, or almost reaches, the pressure dew point before the compressed gas enters the drying device.

[0097] For the sake of clarity, the following example based on an adsorption dryer is used. Here, a pressure dew point of less than -20 °C may be required. The dryer provides this value only when the inlet temperature of the compressed air is less than +50 °C. Note that this value may also depend on the pressure and regeneration temperature as well as further variables. Thus, for example, compressed air at 200 °C is cooled to 50 °C, where condensate also precipitates and is separated as completely as possible. Thereafter, the relative humidity can reach 100%, and thus the pressure dew point can reach 50 °C. Thereby, the dryer provides a pressure dew point of -20 °C.

[0098] If it is cooled more strongly, for example, up to 30 °C, the dryer reaches, for example, a pressure dew point of -35 °C. Here, the energy consumption of the dryer decreases only slightly. Therefore, it may be more efficient to use somewhat more cooling water for the intermediate cooling and jacket cooling and to supply less water for cooling to the aftercooler.

[0099] Thereby, it can be achieved that the compressed gas in the drying device releases moisture to the drying device as easily as possible, that is, with as little energy input as possible. In particular, the lower the temperature of the compressed air at the inlet to the dryer, the lower the pressure dew point achievable in the dryer. If the inlet temperature to the dryer is lower, the moisture load on the dryer can also be lower if a condensate separator and condensate discharger are installed in front of the dryer.

[0100] Furthermore, in relation to the pressure dew point, which is sometimes simply referred to as the dew point, the following should be noted. For the downstream process, the dew point after the dryer can be important. In both the refrigeration dryer and the adsorption dryer, by adapting the temperature before the dryer, it is considered possible to adjust the pressure dew point after the dryer, that is, at the outlet or the handover position to the application of the compressed gas. Furthermore, further measures described in Patent Document 2 can be provided.

[0101] However, in the adjustment cascade, the inlet temperature to the dryer can also be obtained from the pressure dew point after the dryer. Here, the pressure dew point and the temperature can almost coincide by means of a condensate separator before the dryer. For the sake of clarity, this is sometimes explained as if the dew point is adjusted before the dryer, but since temperature measurement is much simpler, only the temperature before the dryer is measured and the dew point before the dryer is not measured.

[0102] According to one aspect, it is proposed that a compressor device, in particular a cooling device, is prepared such that the coolant flow is controlled so that the total coolant outlet temperature as the temperature of the coolant flowing out of the primary cooling circuit and / or the secondary cooling circuit is adjusted to a specified target outlet temperature. The primary cooling circuit and the secondary cooling circuit supply cold coolant to the connected coolers, and the coolant is then heated in each cooler by the coolant flow (i.e., controlled by each cooler). The coolant flow thus heated then rejoins in the primary cooling circuit or the secondary cooling circuit to form a total coolant flow, which exits the primary cooling circuit or the secondary cooling circuit at a specific location. At this outlet, the temperature of the outflowing coolant, i.e., the total coolant outlet temperature, is captured, and thus this temperature is determined by all the heating that the individual coolant flows have received through their respective coolers.

[0103] Here, it can be particularly important that the total coolant flow is reused, for example, for heating, or that another requirement is imposed on the temperature of the outflowing total coolant flow, for example, for discharge into a river.

[0104] On the other hand, if the total coolant outlet temperature is too low, it implies that the cooling is too strong, which is not desirable. This is because at this time, the recooling device cannot cool the desired temperature with a volume flow rate that is too high and a temperature difference that is too small, or especially when fresh water is used, the cooling water cost, or the pump output and fan output, as well as the related costs increase. However, for the compressor, good intermediate cooling and good jacket cooling are helpful. Also, for the dryer, good cooling after the second compressor stage is helpful. However, unnecessarily strong cooling is inefficient.

[0105] Therefore, it has been recognized that it is advantageous to adjust the total coolant outlet temperature to a specified target outlet temperature. This particularly ensures that sufficient cooling is obtained and efficient cooling is also obtained. Furthermore, the higher the temperature level, that is, the higher the total coolant outlet temperature, the more likely it is possible to better utilize the waste heat.

[0106] The compressor device or the cooling device is designed to control the coolant flow by comprising a corresponding control program that can receive the relevant temperature as a measured value and output a control command for controlling the relevant control means accordingly. Such a control program can be implemented on a corresponding process computer of the compressor device, especially the cooling device, and the process computer is provided with a corresponding interface for receiving the required temperature value and presenting the control value to be presented.

[0107] The target value for adjustment or control can be specified by a higher-level control function, that is, a common control device. Therefore, the coolant outlet temperature of the total coolant flow can be specified, for example, by a heating control function, according to the outside air temperature, and by the heating curve of the building to be heated.

[0108] According to one aspect, it is proposed that a compressor device, in particular a cooling device, be prepared such that the coolant flow of the oil cooler is controlled by associated control means so that a specified oil temperature is adjusted. Here, it has been particularly recognized that efficient operation can be achieved by adjusting the specific oil temperature that can be specified accordingly. It is possible not only to ensure that the oil temperature does not become too high and thus the compressor does not overheat, but also to ensure that the oil temperature does not become too low and that the optimum possible viscosity of the oil for lubricating the bearings and gearbox is achieved, whereby the efficiency of the cooling and / or compressor operation may be reduced. If the oil is too cold, the viscosity of the oil becomes too high, which in particular results in too high a resistance in the bearings, leading to an increase in power consumption. If the oil is permanently too cold, an increase in the water fraction in the oil may further occur, which may have an adverse effect.

[0109] The compressor device or cooling device can be prepared to control at least one coolant flow of the cooler to adjust the corresponding temperature by providing a process computer with the corresponding control function implemented. For this purpose, the process computer can comprise an input interface and an output interface. Temperature values can be received via the input interface, and control values can be presented via the output interface, in particular to the associated control means.

[0110] According to one aspect, it is proposed that the coolant flow of at least one compressed gas cooler, in particular an aftercooler, be controlled by associated control means so that it does not exceed and / or fall below a specified compressed gas outlet temperature. Here, it is particularly contemplated that the compressed gas does not become too hot, which can be achieved by controlling the coolant flow of the corresponding compressed gas cooler. In particular, it is proposed that the coolant flow of at least one compressed gas cooler, in particular an aftercooler, be controlled so that the compressed gas is not cooled more strongly than necessary.

[0111] As an addition or alternative, it is proposed that the coolant flow of at least one housing cooler, in particular a jacket cooler, be controlled such that the coolant outlet temperature of this coolant is lower than the coolant outlet temperature of one of at least one compression gas cooler, in particular an intercooler. Here, it has been particularly recognized that in this way a good distribution of cooling can be achieved and two different coolers, namely a housing cooler and a compression gas cooler, can be adapted to each other. In particular, it is proposed to optimally utilize the available cooling water and in particular to minimize the specific performance [kWh / m 3 . Both jacket cooling and intermediate cooling have an important effect on the generated compression gas volume flow rate and power consumption utilized here.

[0112] The low coolant outlet temperature of the coolant can basically be achieved by increasing the coolant flow rate. That is, here, the coolant flow rate of the housing cooler can be increased until its outlet temperature is lower than the outlet temperature of the coolant of the intercooler. At this time, a correspondingly high cooling performance is achieved by the housing cooler, which also reduces the temperature of the compression gas or at least a part of the compressed compression gas.

[0113] Here, it has been particularly recognized that jacket cooling can have a significant effect on the specific performance. When the housing is optimally cooled, the housing takes on an optimal size and thus the gap is minimized. When the housing becomes hot relative to the rotor due to poorer cooling of the housing, the gap between the rotor and the housing, and further the gap between two rotors, becomes larger. As a result, more of the already compressed gas flows back from one chamber to the previous chamber. This reduces the mass flow rate of the gas fed, increases the power consumption, and the gas becomes hotter.

[0114] Intermediate cooling, similarly, has an effect on the specific performance. The higher the temperature at the inlet of the second compressor stage, the higher the corresponding intermediate pressure. The reason is that although the volume flow rate of the second compressor stage remains constant, at a higher gas temperature, this volume flow rate can only be achieved at a higher pressure. The mass flow rate is already specified by the first compressor stage.

[0115] Therefore, it is possible to avoid the first compressor stage having to compress to a higher pressure than when the intermediate cooling is poorer.

[0116] According to one aspect, it is proposed that the coolant flow of at least one housing cooler, in particular a jacket cooler, is controlled such that the difference between the coolant outlet temperature at the outlet of the housing cooler and the coolant inlet temperature at the inlet of this coolant into the housing cooler is - less than a predetermined first value, and / or - exceeds a predetermined second value, and / or - between a predetermined third value and a fourth value

[0117] Here, it has been recognized that it is particularly advantageous to provide a programmed minimum warming.

[0118] Here, it has been recognized that in many cases, it may be good to cool as well as possible, i.e., pass as much water as possible. However, it has also been recognized that there can be a limit beyond which this is no longer beneficial. This is because the additional cost becomes disproportionate to the usefulness. A large amount of cooling water is advantageous for the gas compression process, but a large amount of cooling water or pump output is costly.

[0119] ​To give an example for illustration, when the water volume flow rate for jacket cooling doubles, and thereby the heating of the water decreases from 40K to 20K, this is in most cases beneficial and economical. However, to give a further example, when the water volume flow rate for jacket cooling is doubled and thereby the heating of the water decreases from 2K to 1K, this is no longer beneficial or economical because the additional costs on the water side, i.e., for cooling, exceed the savings on the gas side, i.e., for compressed gas generation.

[0120] According to one aspect, at least in part, an adjustment for the minimum heating of the cooling water in one, several, or all heat exchangers is implemented. This has great practical significance in jacket cooling and is also important in other coolers and in oil coolers.

[0121] In some coolers, when an unattainable gas temperature is specified, i.e., for example, when the compressed gas temperature is specified to be lower than the coolant temperature of the total coolant flow at the inlet, an adjustment for the minimum heating can intervene.

[0122] A further reason for the adjustment for the minimum heating was recognized to be that an overly large water volume flow rate or an overly high flow velocity can cause damage. However, when there is no measuring device for the flow velocity, the flow velocity can be evaluated by the temperature rise. As long as the minimum temperature rise is achieved, it can be ensured that the maximum allowable flow velocity is not exceeded even at maximum output.

[0123] According to the present invention, a method for operating a compressor device is also proposed. Here, the compressor device includes a compressor for compressing gas to generate compressed gas, particularly compressed air, and a cooling device. The cooling device includes an oil cooler for cooling the oil heated by the compressor, at least one compressed gas cooler for cooling the gas that has been completely or partially compressed into compressed gas, and at least one housing cooler for cooling the housing of the compressor or a part of the housing. The oil cooler, at least one compressed gas cooler, and at least one housing cooler each achieve cooling by means of a coolant flow consisting of a fluid coolant, particularly water. Each coolant flow is individually controlled by individual controllable control means such that the cooling performance with respect to the oil cooler, at least one compressed gas cooler, and at least one housing cooler is individually controlled.

[0124] Therefore, the method according to the present invention uses a compressor device provided with a compressor and a cooling device, which is the same as that described above with respect to the aspect related to the compressor device provided with a compressor and a cooling device. At least one compressor device according to one of the above-described aspects is used.

[0125] This method operates in the same manner as described above for the embodiment of the compressor device. In particular, the method steps prepared to be performed by the compressor device or the cooling device are executed according to the method according to the present invention or according to an aspect of the method according to the present invention.

[0126] Therefore, it is particularly proposed that the method for operating a compressor device according to the present invention uses a compressor device according to at least one of the above-described aspects.

[0127] Hereinafter, the present invention will be described in more detail by way of examples based on embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0128]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0129] FIG. 1 shows a compressor device 100 including a compressor 130 having a first compressor stage 131 and a second compressor stage 132. The compressor 130 and other elements are shown schematically.

[0130] Furthermore, an intercooler 133 and an aftercooler 134 are provided, which may also be referred to as a compressed air intercooler and a compressed air aftercooler, respectively. Since the intercooler is disposed between the first compressor stage and the second compressor stage, it is shown here as part of the compressor 130, but may be configured as a separate element. Correspondingly, the aftercooler 134, which is not shown as part of the compressor 130, may be part of the compressor in another form.

[0131] To cool the first compressor stage 131 and the second compressor stage 132, a first jacket cooling mechanism 141 and a second jacket cooling mechanism 142 are provided. The jacket cooling mechanisms 141 and 142 are respectively incorporated into the compressor stage 131 and the compressor stage 132.

[0132] Furthermore, an oil cooler 135 is also provided. The oil cooler 135 is connected to the oil circuit 145 of the compressor 130. For better visibility, the connection between the oil circuit 145 and the compressor 130 is not shown in this figure nor in most of the other figures.

[0133] To cool the entire compressor device 100, a primary cooling circuit 150 having a coolant inlet portion 151 and a coolant return portion 152 is provided. The coolants, i.e., the coolers described above, namely the intercooler 133, the aftercooler 134, the first jacket cooler 141 and the second jacket cooler 142, and the oil cooler 135, are supplied with cold coolant, i.e., water in the illustrated example, through this primary cooling circuit, i.e., the coolant inlet portion 151. The water heated by the cooler in this way flows back through the coolant return portion 152 to the heat sink 154 (shown only abstractly). The heat sink 154 may be a component of the compressor device 100, but it is not necessarily so. A primary heat exchanger 156 is provided in or as the heat sink, and the common coolant flow in the primary cooling circuit 150 can be achieved by the primary coolant pump 158.

[0134] The above-mentioned coolers, namely the intercooler 133, the aftercooler 134, the first jacket cooler 141 and the second jacket cooler 142, and the oil cooler 135, are connected in parallel within the primary cooling circuit. As a result, coolant is supplied from the primary cooling circuit 150 to all of the above-mentioned coolers. For this purpose, each cooler is connected in parallel to the primary cooling circuit via an intercooler line 163, an aftercooler line 164, a jacket cooler line 166, or an oil cooler line 165.

[0135] Therefore, the jacket cooler line 166 first supplies the first jacket cooler 141 and the second jacket cooler 142. Here, in the example according to FIG. 1, the first jacket cooler 141 and the second jacket cooler 142 are connected in parallel.

[0136] In order to set the coolant flow rate or their ratio to each other, manually adjustable valves, namely a manual intercooler valve 173, a manual jacket cooler valve 176, and a manual oil cooler valve 175, are provided. An aftercooler regulating valve 174 is provided so that the intercooler 133 and the aftercooler 134 can be better adapted to each other.

[0137] Furthermore, a primary regulating valve 159 is provided that can control the return flow rate of all the coolant in the coolant return section.

[0138] Furthermore, an oil bypass valve 185 is also provided that can control the flow of oil through the oil cooler 135.

[0139] Therefore, although Figure 1 shows a functional cooling concept, further improvements to it have been recognized. In particular, the individual coolers are not well adapted to each other, at least in part, and have been found to cool with different strengths. It has been recognized that there is a need for improvement here in order to achieve good, uniform, and thus efficient cooling for the compressor device 100. Similarly, it has also been recognized that there is a need for adapted cooling for each cooler. This may also depend on the operating state of the compressor device, especially its cooling device. In particular, the need for adapted cooling may depend on the final pressure, rotational speed, suction temperature, cooling water inlet temperature T10, and the desired cooling water outlet temperature T14 at the temperature measurement point.

[0140] Therefore, it should be noted that the compressor device 100 consists of a compressor 130 and a number of the above-mentioned coolers (including the primary cooling circuit), and the above-mentioned coolers including the above-mentioned primary cooling circuit (and possibly a further secondary cooling circuit) can be understood as the cooling device of the compressor device.

[0141] In particular, the following drawbacks occur:

[0142] The distribution of the water volume flow rate in the parallel coolers had to be set manually, but the distribution of the heat output, and thus the water temperature, can vary significantly depending on the operating point.

[0143] When the desired outlet temperature T14 at the temperature measurement point is higher, the oil cooler and the jacket cooling mechanism have to be cooled separately with cooling water, which can be done by a secondary cooling system.

[0144] Due to various disturbance variables, obvious deviations can occur between the individual outlet temperatures T11, T12, T13, T16.

[0145] Generally, the use of cooling water becomes inefficient. Stage damage can occur due to cooling water that is too cold.

[0146] Similarly, the following have also been identified as disadvantages.

[0147] The water outlet temperature was adjusted by the common valve V14.

[0148] The oil temperature was adjusted by bypassing the oil cooler. The oil cooler generally received more water than necessary so that it could cool sufficiently even in the worst case.

[0149] The aftercooler generally received more water than necessary so that it could cool sufficiently even in the worst case. Only the temperature T11 = T12 was adjusted by the valve V12 so that different heat outputs in the aftercooler could be corrected.

[0150] The jacket cooling mechanism generally received too little water to achieve the desired outlet temperature T14, but there was also too much water and it was too cold, which could cause damage to the stage.

[0151] The intermediate cooling mechanism receives only enough water to achieve the desired mixed outlet temperature T14.

[0152] When a component temporarily requires better cooling, V14 opens further, whereby all heat exchangers receive more water, but the desired water outlet temperature T14 is no longer achieved.

[0153] Figure 2 shows a partial view of a compressor device including a primary cooling circuit 250, which may basically correspond to the primary cooling circuit 150 of FIG. 1. FIG. 2 particularly shows the primary cooling circuit 250. This can be controlled by a primary regulating valve 259 that may correspond to the primary regulating valve 159 of FIG. 1 to supply coolant to the connected coolers. The flow rate through the primary cooling circuit 250 can be controlled by the primary regulating valve 259. Thereby, various connected coolers, particularly various connected heat exchangers, are also controlled. In particular, here, the oil cooler 235 configured as a heat exchanger is supplied with coolant through the primary cooling circuit 250. Similarly, a parallel line 290 is provided, and the parallel line 290 is connected in parallel to the cooling section supplying the oil cooler 235 and can supply, in particular, to the other coolers mentioned in FIG. 1, i.e., in particular, the intercooler 133, the aftercooler 134, and the first jacket cooler 141 and the second jacket cooler 142.

[0154] The primary cooling circuit 250 can be connected to the heat sink via an interface 292, as shown in FIG. 1.

[0155] Thus, referring to FIG. 2, conventionally, in a dry runner, there was a regulating valve V14 in the primary circuit 250, and the regulating valve V14 collectively adjusted the flow rate through a plurality of parallel heat exchangers.

[0156] There was only a manual valve to set the flow rate distribution.

[0157] Only the heat exchanger related to stage 2 already had its own regulating valve because the deviation was the largest there.

[0158] FIG. 3 shows a compressor device 300 according to one embodiment. This compressor device 300 is very similar to the compressor device 100 in FIG. 1 and includes a compressor 30 having a first compressor stage 1 and a second compressor stage 2 with a first jacket cooler 41 and a second jacket cooler 42. In the illustrated embodiment, the first jacket cooler 41 and the second jacket cooler 42 are connected in series with each other.

[0159] Furthermore, an intercooler 3 and an aftercooler 4 for cooling the compressed gas are provided respectively. Here, the intercooler 3 cools the partially compressed compressed gas, and the aftercooler 4 cools the fully compressed compressed gas.

[0160] Similarly, an oil cooler 5 for cooling the oil flowing through the compressor 30 is also provided.

[0161] All of the coolers 3, 4, 5, 41, 42 described above are connected to the primary cooling circuit 50, and thus the primary cooling circuit 50 supplies the coolant to those coolers. To operate the primary cooling circuit, a primary heat exchanger 10 and a primary coolant pump 12 are provided as shown in FIG. 1. The primary heat exchanger 10 and / or the primary coolant pump 12 may or may not form part of the compressor device respectively.

[0162] Here, according to the present invention, each cooling element connected to the primary cooling circuit 50 is intended to be controllable by unique, i.e., individual, control means, rather than manually, especially by controllable control means. For this purpose, regulating valves V11, V12, V13, and V16 are respectively provided, and these regulating valves are respectively arranged in the coolant lines connected in parallel to the primary cooling circuit to control the coolant flow through the respective cooling elements. In this embodiment and all other embodiments, the regulating valve may also be simply referred to as a valve. Thereby, the coolers connected in series are assembled so as to be one cooling element each. Therefore, the intercooler 3, the aftercooler 4, and the oil cooler 5 each form one cooling element.

[0163] Thereby, the first jacket cooler 41 and the second jacket cooler 42 are combined to form a common jacket cooler 341, and thus this jacket cooler 341 forms a cooling element and is controlled via the regulating valve V13. Alternatively, separate valves are also possible.

[0164] Therefore, the above-described cooling elements, i.e., the intercooler 3, the aftercooler 4, the oil cooler 5, and the jacket cooler 341, can be controlled individually, thereby realizing a suitable cooling concept for the compressor device 300.

[0165] In particular, in order to control each cooling element or to control the regulating valves V11 to V13 and V16 therefor, it is intended to capture and take into account the temperature of the coolant, i.e., the cooling water. For this purpose, corresponding temperature measurement points T10 to T16 are provided. Thereby, the cooling mechanisms can be adapted to each other, which can be done based on the corresponding temperatures of the cooling flows, including the total coolant flow of the primary cooling circuit 50.

[0166] As a supplement, other temperatures can also be captured. For this purpose, in the embodiment of FIG. 3, the oil temperature is captured at the temperature measurement point T60. It is also possible to capture further temperatures, in particular at least one temperature of the compressed gas indicated by the temperature measurement point T51. Here, in this figure, T100 represents the same outlet temperature from the compressor device where T51 is also provided. However, it is also possible to capture the temperature of the compressed gas, especially between the first compressor stage 1 and the second compressor stage 2, or also at other locations including where the compressed gas is not yet fully compressed, for example, in front of the first compressor stage 1.

[0167] Preferably, all these temperatures can be included in the control of the cooling, and thus in the control of the regulating valves V11 to V13 and V16. However, it is not necessary to take into account all the temperatures. Preferably, at least one temperature is taken into account.

[0168] Thus, the compressor device according to FIG. 3 has a compressed air intercooler 3, a compressed air aftercooler 4, an oil cooler 5, and stages 1, 2 having jacket cooling mechanisms 41, 42.

[0169] In this exemplary embodiment, for example, there is a cooling water circuit 50 provided with a heat exchanger 10 for heat recovery. The heat exchanger 10 can be used for waste heat utilization, but it is also possible to use a cooling system that is not used for waste heat utilization.

[0170] However, when combined with waste heat utilization, its usability is particularly increased.

[0171] The water volume flow rates through the components 3, 4, 5, 1, 2, and 41, 42 can be individually and optimally set by the four regulating valves V11, V12, V13, and V16.

[0172] The adjustment of the (mixed) water outlet temperature T14 of the compressor is possible by the above valves V11, V12, V13, V16.

[0173] In particular, in order to eliminate steam bubble generation and the associated risks, it is proposed to take into account the temperatures at measurement points T11 and T12 after the first compressor stage and the second compressor stage, and thus according to this figure.

[0174] In order to adjust the water volume flow rate through the oil cooler, it is proposed to include at least one oil temperature at measurement point T60, for example, in the control. Alternatively, the component temperature, such as the bearing outer ring temperature, can also be used.

[0175] Particularly preferably, in order to protect the second compressor stage from overheating, it is proposed to include in the control the inlet temperature of the compressed gas to the second compressor stage, and thus in particular the temperature at measurement point T31 shown in FIG. 4.

[0176] Particularly preferably, it is proposed to include in the control the outlet temperature of the coolant at the outlet from the jacket cooler of the second compressor stage or the first compressor stage, that is, the temperatures at measurement points T13 and T15 according to the corresponding figure. This is proposed to eliminate steam bubble generation.

[0177] Preferably, it is proposed to include in the control the outlet temperature of the compressed gas at the outlet from the compressor device. This may be the temperature at measurement point T100 according to the corresponding figure. It is proposed to take these into account in individual adjustment and optimization.

[0178] The mixed water outlet temperature, that is, the outlet temperature of the total coolant flow, that is, the temperature at measurement point T14 according to the corresponding figure, is recognized as important, and it is proposed to include it in the control.

[0179] Similarly, the temperatures at measurement points T100, T14, and T60 are also recognized as important. Particularly preferably, these are included in the control.

[0180] Furthermore, it has also been recognized that for each valve, at least one temperature sensor, particularly the corresponding measurement points, is advantageous for adjustment. Therefore, it is proposed to provide these temperature sensors and include them particularly in the control.

[0181] To control valve V11, it is proposed to use at least one, a plurality, or all of the temperatures at measurement points T14, T11, and / or T31. Preferably, furthermore, the temperatures at at least one of the measurement points T2 and T4, T12 and T10 shown in FIG. 4, and optionally additional measurement points can also be used.

[0182] To control valve V12, it is proposed to use at least one, a plurality, or all of the temperatures at measurement points T100, T14, T12, and / or T51. Preferably, furthermore, at least one of the temperatures at the measurement points or temperatures T52 and T85 and M85 shown in FIG. 4, and optionally additional measurement points or additional temperatures can also be used.

[0183] To control valve V13, it is proposed to use at least one, a plurality, or all of the temperatures at measurement points T13, T15, and / or T23 partially shown in FIG. 4. Preferably, furthermore, at least one of the temperatures at the measurement points T2 and T4, T14 or T29, and T10 or T20 partially shown in FIG. 4, and optionally additional measurement points can also be used.

[0184] To control valve V16, it is proposed to use at least one oil temperature, particularly at least one of the temperature measurement points T60 and / or T66 partially shown in FIG. 1. Additionally or alternatively, at least one characteristic component temperature, such as a bearing temperature, can also be used. Preferably, furthermore, the temperatures at the measurement points T16, T14 or T29, and T10 or T20 partially shown in FIG. 4, and optionally additional temperatures or additional measurement points can also be used.

[0185] The following figures show other embodiments, and for better visibility and to better show the relevance, some of the reference signs identical to those of the embodiment of FIG. 3 are used. However, in this regard, it is not essential that the elements are actually identical. For example, if a third or fourth compressed gas cooler is supplemented to the intercooler and the aftercooler, it is considered that the intercooler and the aftercooler can be dimensioned smaller accordingly. However, for better visibility, in the following embodiments as well, the same reference signs, namely 3 and 4, are used for the intercooler and the aftercooler respectively.

[0186] FIG. 4 shows an embodiment of a compressor device 400 comprising a jacket cooler heat exchanger 6 (which may also be simply called a heat exchanger) for a first jacket cooler 41 and a second jacket cooler 42. Here too, the jacket coolers 41, 42 are connected in series, but the coolant flow through the jacket coolers 41, 42 is pushed forward by a jacket cooler pump 14 and thus drives a separate cooling circuit (which may also be called a compressor cooling circuit). This is because the coolant flows through the corresponding jacket regions in the first compressor 1 and the second compressor 2. Thus, the jacket cooler pump 14 is a cooling water pump for the compressor cooling circuit 32. This compressor cooling circuit 32 is guided through the heat exchanger 6, i.e., through the primary side of the jacket cooler heat exchanger 6. Through the secondary side of the jacket cooler heat exchanger 6, the coolant from the primary cooling circuit 50 flows. The corresponding coolant flow from the primary cooling circuit 50 through the jacket cooler heat exchanger 6 is controlled by a regulating valve V13.

[0187] Preferably, the valve V13 is controlled in response to the temperature T13 and / or T15. Then the temperature T23 is obtained. The temperature at the measurement point Txx is sometimes simply called the temperature Txx synonymously hereinabove and hereinafter.

[0188] The temperature T13 and / or T15 is considered to be more important than T23. However, T23 can alternatively be used.

[0189] There is a risk of steam generation at both the temperature measurement points T13 and T15. Therefore, it is proposed to measure these temperatures there.

[0190] During a cold start, V13 remains closed, and therefore there is no coolant flow at T23. Therefore, no temperature rise occurs at the temperature measurement point T23.

[0191] The temperature measurement points T13 and T15 are preferably arranged directly at the outflow part at a higher position. Thereby, even without active circulation, the temperature rise can be captured, and accordingly, the jacket cooler pump can be started first. Subsequently, this causes a forced flow at the temperature measurement points T13 and T15, and thus good temperature measurement can be obtained. However, the valve V13 can continue to be closed, and therefore measurement is not possible here, and thus adjustment is not possible either. When the temperature T13 and / or T15 further rises, the valve V13 is opened by a control function, which may also be called "open adjustment". Only then can the temperature at the measurement point T23 be used for adjustment.

[0192] The regulating valve V13 is sometimes called the jacket cooler regulating valve and controls the coolant flow through the jacket cooler heat exchanger 6. The valve V13 controls the coolant volume flow rate for the jacket cooler mechanism heat exchanger 6. In other forms, it is also possible to control the coolant volume flow rate for the jacket coolers 41, 42. The valve V13 controls the temperatures T13 and T15 related to the jacket cooler, and possibly further temperatures. The volume flow rate for the jacket cooler mechanisms 41, 42 is controlled by the jacket cooler mechanism pump 14 in the form of this Figure 4.

[0193] FIG. 4 further includes a second aftercooler 7 and a third aftercooler 8, which may also be referred to as second and third compressed air aftercoolers or compressed gas aftercoolers, or may simply be referred to as heat exchangers as they are preferably implemented as heat exchangers. These are arranged downstream of the compressed gas line 34, i.e., downstream of the aftercooler 4 or the compressed gas aftercooler 4. Thereby, additional cooling of the compressed gas can be achieved.

[0194] As also shown in the embodiment of FIG. 4, it is particularly preferred to use a dryer for compressed gas, in particular an adsorption dryer 20, incorporated in the compressed gas line 34. In the case of a refrigeration dryer, an additional aftercooler is similarly beneficial for adjusting the dew point and the outlet temperature in this regard. However, as shown, the dryer aftercooler 8 is not very beneficial in the case of a refrigeration dryer. In the case of a refrigeration dryer, the heat exchanger 8 can be used to warm the compressed air. Therefore, the use of an adsorption dryer is particularly proposed here. In an adsorption dryer, the heat exchanger 8 is particularly used to cool the compressed air.

[0195] Here, in particular, it is proposed that the compressed gas dryer 20 be arranged behind the second aftercooler 7 and in front of the third aftercooler 8 in the flow direction of the compressed gas.

[0196] In order to control the coolant flow through both the second aftercooler 7 and the third aftercooler 8, regulating valves V25 and V28 are provided respectively. Therefore, the second aftercooler 7 and the third aftercooler 8 can also be controlled independently of each other.

[0197] Furthermore, temperature measurement points T25 and T28 are provided respectively and are assigned to the second aftercooler 7 and the third aftercooler 8, and thus to the corresponding regulating valves V25 and V28.

[0198] Here, in particular, it has been recognized that the dryer can be supported by the second heat exchanger 7, and thus the pressure dew point after the dryer may be affected. However, this also causes the outflow temperature from the dryer to decrease, which may or may not be desirable.

[0199] The heat exchanger after the dryer can bring the compressed air to an optimal temperature for downstream applications. In an adsorption dryer, the air at the outlet may be significantly hotter than the air at the inlet, so cooling may be required again here.

[0200] The control valve V25 that controls the coolant flow through the second aftercooler 7 can control this coolant flow according to the temperature captured by the temperature measurement point T25. However, preferably, the air outflow temperature T52 is adjusted by the valve V25. In a system with a dryer, the target value for this temperature T52 is obtained by an adjustment cascade from the desired pressure dew point after the dryer. In a system without a dryer, the target value for the temperature T52 is obtained from the target value for the temperature T100 that can be specified externally.

[0201] According to a further aspect, adjustment according to the temperature T25 or the temperature difference T25 - T20 is also possible.

[0202] That is, the control valve V25 controls the coolant flow according to the outflow temperature of the compressed air at the temperature measurement point T52 from the second aftercooler 7.

[0203] Similarly, it is also contemplated that the control valve V28 that controls the coolant flow through the third aftercooler 8 adjusts the compressed air outflow temperatures T86 or T100 shown in FIG. 6. According to an alternative aspect, adjustment according to the temperature T28 or the temperature difference T28 - T20 is contemplated.

[0204] Therefore, this can be done according to the temperature of the temperature measurement point T28, and thus it is possible to control the coolant flow according to the coolant temperature at the outlet of the third aftercooler 8.

[0205] Regarding the second aftercooler 7 and the third aftercooler 8, a secondary cooling circuit 80 is provided to supply coolant.

[0206] The secondary cooling circuit 80 can release heat again via the secondary heat exchanger 11, and its coolant flow can be driven by the secondary coolant pump 13. With this secondary cooling circuit, almost independent cooling by the second aftercooler 7 and the third aftercooler 8 is possible, that is, independent of other coolers and the primary cooling circuit.

[0207] In the illustrated embodiment, it is further contemplated that the secondary cooling circuit 80 cools the coolant flow of the primary cooling circuit, particularly the total coolant flow. For this purpose, a corresponding primary-secondary heat exchanger 9 is provided. For control, a regulating valve V10 is also provided, and thus the regulating valve V10 is arranged in the coolant line of the primary-secondary heat exchanger 9. The control of the regulating valve V10 can be performed according to the return temperature of the coolant exiting the primary-secondary heat exchanger 9. For this purpose, a temperature measurement point T10 is provided. The temperature of the coolant flowing through the regulating valve V10 can be captured at the temperature measurement point T24.

[0208] Similarly, in the embodiment shown in FIG. 4, it is proposed to split the primary coolant pump 12 according to FIG. 3, that is, instead, two primary coolant pumps 12a and 12b are provided, one in front of the primary-secondary heat exchanger 9 and the other behind the primary-secondary heat exchanger 9. Furthermore, a primary circuit bypass 21 can be provided, and through the primary circuit bypass 21, a part of the total coolant flow of the primary cooling circuit 50 bypasses the primary heat exchanger 10 and flows. By the internal pump 12b, in conjunction with the bypass 21 and the heat exchanger 9, the operation of the compressor, and thus the compressed air supply, can be maintained even when the external heat sink 10 and / or the pump 12a are not available. This may also apply, for example, during maintenance work or renovation measures, or when there is a seasonal heating demand.

[0209] The external pump 12a is designed in particular with respect to the heat exchanger 10 and the piping, and possibly also with respect to the external pressure losses in further elements. The internal pump 12b can either operate together for support or can be provided only for use when needed. The internal pump 12b is started only when the primary coolant pump 12a delivers little or no water at all and the compressor would otherwise overheat and stop on its own.

[0210] Furthermore, a pressure dew point temperature measurement point M85 is provided after the drying device 20. Therefore, the pressure dew point temperature at that point is determined, and cooling can be controlled accordingly. In particular, it is proposed to control the second aftercooler 7 and / or the valves V25 and / or V28 according to the pressure dew point temperature.

[0211] In particular, the pressure dew point after the dryer is important. At the inlet of the dryer, the compressed air is generally 100% saturated. Therefore, assuming that the condensate that precipitates here is separated and discharged as completely as possible before the dryer, the temperature and the pressure dew point are approximately the same.

[0212] For the result of drying, the temperature of the compressed gas at the inlet of the dryer is particularly important.

[0213] If the condensate is not separated before the dryer, the result of drying will be somewhat worse. However, the compressor should be designed so that the condensate that will precipitate is separated in advance.

[0214] For clarity, the condensate separator and discharger are not shown.

[0215] Separately from that, in the embodiment of FIG. 4, as compared with the embodiment of FIG. 3, it is contemplated to accept some further temperatures. For this purpose, as far as shown in FIG. 4, temperature measurement points T1 to T100 are provided overall.

[0216] The following is a summary of some essential aspects of the design according to FIG. 4 in particular.

[0217] Here, the compressor device according to FIG. 4 further has two auxiliary coolers 7, 8.

[0218] In this design, there are two cooling water circuits 50, 60, and coolers and jacket cooling mechanisms are distributed to them.

[0219] By way of a preferred example, the secondary circuit 80 can be provided with a cooling tower 11 for removing heat.

[0220] The water volume flow rates through the auxiliary coolers 7, 8 can also be individually and optimally set by two regulating valves V25 and V28.

[0221] Here, when adjusting the valves, the measured pressure dew point M85 is also taken into account and thus optimized. To set the pressure dew point, valves V25 and V12 can be controlled.

[0222] In particular, the outlet temperature T100 is used to control valve V28. The temperature T100 is also affected by valves V25 and V12.

[0223] The embodiment of FIG. 5 is also based on the embodiment according to FIG. 3 and further includes a secondary cooling circuit 580 as a supplement, but this secondary cooling circuit 580 is provided only for the purpose of cooling the total coolant flow of the primary cooling circuit 50. To this extent, the form of the secondary cooling circuit 580 corresponds to the form of the secondary cooling circuit 80 of FIG. 4, particularly with regard to the connection via the primary-secondary heat exchanger 9.

[0224] The primary bypass 21 as shown in FIG. 4 is not provided in the embodiment according to FIG. 5, but still, the use of such a bypass is considered here as well.

[0225] The embodiment of FIG. 5 further includes a primary bypass control valve V19, which may also simply be referred to as bypass valve V19. Through this valve V19, a portion of the total coolant flow of the primary cooling circuit 50 can be supplied to the intercooler 3 and the aftercooler 4 before the tap (and also after the tap according to one embodiment) through the first jacket cooler 1, the second jacket cooler 2, and the oil cooler 5. In this regard, unlike the embodiment of FIG. 3 and also the embodiment of FIG. 4, in the embodiment of FIG. 5, the intercooler 3 and the aftercooler 4 can directly receive a portion of the cooling flow that has not yet been heated by the oil cooler 5 and the first jacket cooler 41 and the second jacket cooler 42 only through this primary bypass control valve V19. That is, in this embodiment of FIG. 5, the heat absorbed by the coolant in the oil cooler 5 and the first jacket cooler 41 and the second jacket cooler 42 is conducted through one of the two compression gas coolers, i.e., the intercooler 3 or the aftercooler 4, as long as a portion of the coolant flow is not bypassed by the primary bypass control valve V19.

[0226] This is proposed as an optimized circuit configuration for waste heat utilization at high temperature levels. The oil cooler and the jacket cooling mechanism here receive the maximum volume flow of primary water that has not yet been preheated and still has the temperature T10.

[0227] The primary bypass control valve V19 is used particularly during cold start. When the oil has not yet reached the operating temperature, the primary bypass control valve V19 is closed. In particular, when the temperature at the temperature measurement points T10, T13, T15 is low and the coolant, i.e., the water, is still cold, the control valve V13 may also be closed. However, it has been recognized that the valves V11 and V12 should control a sufficient water flow very quickly after cold start. Therefore, it is proposed to open the valve V19 during cold start. During operation, when the cold start process is completed, it is proposed to close the bypass valve V19 slightly again so that the oil cooler and the jacket cooling mechanism can receive a relatively high cooling water volume flow.

[0228] The specified water outlet temperature at measurement point T14, i.e., the target temperature, can only occur by mixing the partial coolant flows having temperatures T11 and T12. With these two coolers, a higher outlet temperature can be achieved. In particular, this enables achieving a high outlet temperature T14.

[0229] It has been recognized that the following advantages can be obtained.

[0230] The waste heat from the oil cooler and the jacket cooling mechanism can be provided for waste heat utilization even at water temperatures that were not previously possible.

[0231] Only the partial coolants having temperatures T11 and T12 are mixed, thereby producing a mixing temperature, which is not reduced by the mixing of the coolants having temperatures T16 and T15. Thus, a higher target temperature regarding the outlet temperature T14 can be achieved.

[0232] Therefore, a high temperature that would normally require a hot water system and, at the same time, high performance can be achieved by the water system.

[0233] The following is a summary of some essential aspects of the design according to FIG. 5. Here, the embodiment of FIG. 5 does not include an auxiliary cooler.

[0234] Here too, there are two cooling water circuits 50, 580.

[0235] The coolers 3, 4, 5, and the jacket cooling mechanisms of stages 1, 2 are within the primary circuit 50. At this time, first, there is a parallel connection of the oil cooler 5 and the jacket cooling mechanisms of stages 1, 2. Then, the intercooler 3 and the aftercooler 4 are connected in series. These are also connected in parallel with each other.

[0236] Here, the secondary circuit 580 cools the primary circuit 50 as needed.

[0237] This form of connection deformation provides particular advantages in the heat recovery by the heat exchanger 10, which may also be referred to as waste heat utilization.

[0238] The embodiment according to FIG. 6 corresponds to the embodiment of FIG. 4, but the difference is that the second aftercooler 7 and the third aftercooler 8 are connected in parallel to the primary cooling circuit 50. It is configured in the same way as FIG. 5, and the secondary cooling circuit 580 coupled to the primary cooling circuit 50 is also provided in the same way.

[0239] The intercooler 3 and the aftercooler 4, which may also be referred to as the first aftercooler 4 synonymously in this embodiment and other embodiments, are not connected in parallel to the primary cooling circuit 50 as in the embodiment of FIG. 5, but are connected in series. The coolant is supplied from the primary cooling circuit 50 to the intercooler 3 and the aftercooler 4 after flowing through other coolers. The primary bypass regulating valve V19 as shown in FIG. 5 is not necessary here. Because, in particular, a sufficient water volume flow always flows through the second aftercooler 7 together with the regulating valve V25, and thus the intercooler 3 and the aftercooler 4 connected in series downstream can always receive a sufficient volume flow.

[0240] In order to capture the temperature T100 of the compressed gas at the outlet of the compressor device, a temperature measurement point T86 is provided. Separators Z1 and Z2, which can be configured as cyclone separators in particular, and the condensate discharger K20 are also shown in the same way as in FIG. 6 respectively. These may also exist in other embodiments even if not shown.

[0241] The following is a summary of some essential aspects of the design according to FIG. 6. Here, in this embodiment of FIG. 6, there are auxiliary coolers 7 and 8.

[0242] Here too, there are two cooling water circuits 50 and 580.

[0243] Coolers 3, 4, 5, 7, 8 and the cooler 6 for stages 1 and 2 are in the primary circuit 50. At this time, first, there is a parallel connection of the oil cooler 5, the cooler 6 for stages 1 and 2, and the auxiliary coolers 7 and 8. Then, the intercooler 3 and the aftercooler 4 are connected in series. These are also connected in parallel with each other.

[0244] Here, the secondary circuit 580 cools the primary circuit 50 as necessary.

[0245] The embodiment of FIG. 7 essentially corresponds to the structure of FIG. 3. However, it is different in that it includes the jacket cooler heat exchanger 6 with respect to the first jacket cooler 41 and the second jacket cooler 42, and thus the jacket cooler 341. The structure and the cooling connection regarding the jacket cooling by the jacket cooler heat exchanger 6 are realized as shown in FIG. 6.

[0246] In FIG. 7, further, the intercooler 3 and the aftercooler 4 are each independently connected in parallel to the primary cooling circuit 50. However, at this time, in FIG. 7, as in FIG. 3, a parallel connection of the intercooler 3 and the aftercooler 4 to the primary circuit occurs, and this difference between FIG. 3 and FIG. 7 described is essentially of a structural nature.

[0247] Regarding the embodiment of FIG. 7, but also regarding other embodiments, the following advantages can be obtained.

[0248] By better jacket cooling and intermediate cooling, the specific performance is improved by about 1 - 3%.

[0249] Higher heat recovery performance becomes possible, and in some cases, the need for cooling water is reduced / eliminated.

[0250] Adjustment to a higher water outlet temperature T14 is possible, that is, a higher target value, that is, a value higher than before, can be specified for this water outlet temperature T14 (for example, not about 85°C as before, but 90°C - 95°C).

[0251] If necessary, the compressor can be intentionally cooled better, so higher operating reliability can be achieved.

[0252] Since manual balancing of the line regulating valve is not required, a simple running-in operation is possible.

[0253] The distribution of water is automatically adapted, especially according to season, weather, final pressure, and rotational speed.

[0254] Efficient use of cooling water is possible.

[0255] Lower compressed air consumption can be achieved with an optimal compressed air temperature.

[0256] The following further advantages can also be obtained.

[0257] Optimal adjustment of the mixed water outlet temperature T14 is possible by separate volume flow adjustment for each heat source.

[0258] The user can specify the water outlet temperature T14, the maximum compressed air outlet temperature T100, and optionally the maximum pressure dew point.

[0259] The oil cooler always receives only the amount of water necessary to achieve the optimal oil temperature.

[0260] The aftercooler has little impact on the specific performance. Therefore, the aftercooler receives only the amount of water necessary to achieve the desired, especially the maximum, compressed air outlet temperature T100 or the pressure dew point M85 so that it does not boil, i.e., the temperature, for example T12, remains below 110°C.

[0261] The intercooling mechanism has a great impact on the specific performance and thus receives as much water as possible.

[0262] The jacket cooling mechanism has the greatest impact on specific performance and thus receives a very large amount of water. As a measure of adjustment, the following temperature relationship can be based on: T13 - T10 := 0.5 * (T11 - T10).

[0263] If the component temporarily requires better cooling, it can also be cooled better.

[0264] The embodiment of FIG. 8 essentially corresponds to the embodiment of FIG. 6, but with a slightly different representation. In the illustration of FIG. 8, a primary bypass 21 and a primary bypass control valve V19 are further provided.

[0265] Here, in addition to the primary bypass control valve V19, a heat exchanger control valve V25 for the aftercooler is also provided, and these can be understood as two alternative embodiments. Thereby, a plurality of optional designs are shown more clearly in one figure.

[0266] However, this design can be realized by the primary bypass control valve V19 and the heat exchanger control valve V25. It can be beneficial in special cases, such as when higher temperature compressed air is required in winter. Then, until it becomes impossible to supply sufficient water for the intercooler and the aftercooler without opening the primary bypass control valve V19, the valves V28 and V25 for the aftercooler must be closed.

[0267] By means of the primary bypass control valve V19, it is possible to achieve that a part of the coolant that did not flow through the third aftercooler 8 is supplied to the intercooler 3 and the aftercooler 4. That is, similar to FIG. 6, in the embodiment of FIG. 8, the intercooler 3 and the aftercooler 4 are arranged or connected in series in the primary cooling circuit, but it is contemplated that they are connected in parallel with each other.

[0268] The temperature T85 can be recorded in front of the cooler 8.

[0269] Regarding the designs of FIGS. 5, 6, and 8, the following points need to be noted. In these three embodiments, the intercooler 3 and the aftercooler 4 are connected in series to the primary cooling circuit. For the sake of simplicity, in the following description, the primary bypass control valve V19 is ignored. Therefore, since the intercooler 3 and the aftercooler 4 rely on a series connection, they both receive the complete coolant flow of the primary cooling circuit 50, that is, the total coolant flow. However, in all of these three embodiments, a parallel connection between the intercooler 3 and the aftercooler 4 is provided. Therefore, it has been recognized that individual control means for the intercooler 3 and the aftercooler 4, that is, the control valves V11 and V12 here, are still advantageous. That is, from here, on the one hand, the proportion of the total coolant flow of the primary cooling circuit flowing through the intercooler 3 and, on the other hand, through the aftercooler 4 can be controlled. Therefore, on the one hand, the distribution of cooling within the region between the two compressor stages and, on the other hand, within the region immediately after the second compressor stage can be achieved.

[0270] Regarding the embodiment of FIG. 8 and other embodiments, the following advantages are obtained:

[0271] Maximum heat recovery with sufficient heat removal and operation without cooling water are possible. Therefore, it is also considered that the secondary cooling system 11 does not need to be used and can be prepared for cases where less heat is required or the compressor requires better cooling.

[0272] In this regard, as an application, a connected building heating system is proposed. This can have the following effects. In winter, all the heat can be utilized by the heat exchanger 10. On the other hand, in summer, although less heat is required, the heat still has to be dissipated. At that time, this is done through the primary-secondary heat exchanger 9, the secondary cooling system 11, and the valve V10.

[0273] Depending on temperature requirements and alternative means, about 10 - 30% more waste heat utilization may be possible. Maximum waste heat utilization is possible at a water inlet temperature about 5K - 10K higher.

[0274] A very high water outlet temperature T14 is possible, especially up to about 95°C at maximum.

[0275] Particularly by means of a primary water system having an inlet temperature T10 and an outlet temperature T14, sufficient jacket cooling and oil cooling using heating water at a high volume flow rate are possible.

[0276] Since the cooler 7 receives a large volume flow rate of cold heating water, a sufficient dew point can be achieved.

[0277] If necessary, since the cooler 8 receives cold heating water, a low compressed air outlet temperature is possible.

[0278] FIG. 9 shows a schematic partial cross-sectional view of a compressor device 900 comprising a first compressor stage 901 and a second compressor stage 907. Further, FIG. 10 shows an enlarged view of the first compressor stage 901. Hereinafter, as long as the first compressor stage is described, reference is made to FIG. 9 and further to FIG. 10.

[0279] Here, FIG. 9 shows a dry screw compressor that essentially forms the compressor device 900. Thus, the first compressor stage 901 performs compression of the first stage during operation. In this regard, the first compressor stage 901 comprises a housing 902 and a coolant channel 903 of a jacket cooling mechanism (more clearly shown in FIG. 10 in particular).

[0280] In order to compress compressed gas, especially compressed air, compressor screws 904 that mesh with each other for compression are provided. The compressor screws 904 are driven via the drive shafts 905 of the corresponding compressor stages. The second compressor stage 907 that further compresses the gas, especially compressed air, compressed in the first compressor stage includes a housing 909 having a coolant channel 908 and a compressor screw 910 driven via a drive shaft 911.

[0281] Both drive shafts 905 and 911 are driven by a common drive motor 906, and a gearbox 912 is provided in this regard. The gearbox 912 distributes the driving force from the drive motor to the two drive shafts 905 and 911, thereby driving the compressor screws 904 and 910.

[0282] The two compressor stages 901 and 907 can be cooled by a jacket cooling mechanism realized using the coolant channels 903 and 908. In this regard, a cooling medium, especially cooling water, flows through these coolant channels 903 and 908, which can be controlled collectively or individually.

[0283] According to the present invention, according to at least one aspect, the following aspects can be particularly emphasized.

[0284] In particular, a multi-stage dry compression compressor cooled by water is proposed, including at least one intercooler, an aftercooler, an oil cooler, and a compressor cooler, especially a jacket cooler (sometimes called a housing cooler), for cooling at least one compressor stage housing. The intercooler and the aftercooler each form one compressed gas cooler.

[0285] It is proposed that in each of these cooling devices, that is, in each of these coolers, the flow of water for heat dissipation can be adjusted separately by a unique adjustment mechanism, especially an adjustment valve or an adjustable pump. The adjustment mechanism is sometimes called a control means.

[0286] Furthermore, the following aspects may also be provided. At least two compressed air after-coolers can be provided after the second compressor stage. At least one compressed air dryer with a compressed air cooler arranged downstream for dry compressed air can be provided. The device for cooling at least one compressor housing is configured as a jacket cooling mechanism or a jacket cooler, and / or a heat exchanger for such jacket cooling is provided.

[0287] Adjusting means or control means are provided as separate regulating valves for each individual water flow path in order to adjust the water volume flow rate as the adjustment of the coolant flow rate for each heat exchanger. In particular, a control function for the coolant for each cooler is provided. Each cooler can be provided with one supply line each for supplying coolant to that cooler. This includes the inflow and outflow of the coolant respectively. Each supply line can have an inlet part and an outlet part. Preferably, for each cooler, control means are provided in its supply line. The control means can be at the inlet part or the outlet part respectively. One supply line of one cooler each, in particular each supply line, can be arranged in parallel with the supply lines of some or all of the other coolers.

[0288] The control means or adjusting means for adjusting the water volume flow rate for each heat exchanger can be designed as a separate adjustable pump for each parallel line, i.e., in particular for each supply line. The control means or adjusting means can be provided respectively for adjusting one device, in particular the cooler of at least one compressor housing. A parallel connection of an oil cooler and at least one of these devices, in particular the cooler for cooling at least one compressor housing, is proposed.

[0289] It is proposed that the control means or adjusting means are adjusted or coordinated by a central or common control unit.

[0290] Various connection deformation forms for jacket cooling can be provided. One of them is the parallel connection between the oil cooler and the jacket cooling mechanism or the jacket cooler. Another deformation form is to provide a heat exchanger for the oil cooler and the jacket cooling mechanism so that separate or independent adjustment of the oil temperature and the jacket cooling temperature can be achieved.

[0291] Preferably, a screw compressor is provided as the compressor. As the coolant, in particular, water or a water-glycol mixture can be used.

[0292] When a heat exchanger exists for separation (sometimes also called system separation), especially when it exists for separating the jacket cooling circuit from the primary cooling circuit, two deformation forms can be provided in particular regarding the control of the control means or adjustment mechanism for adjusting the jacket cooling temperature. According to the first deformation form, the control or adjustment is directly performed by controlling or adjusting the coolant flow, especially the flow of water, through the jacket cooling mechanism. According to the second deformation form, the control or adjustment is indirectly performed by controlling or adjusting the coolant flow or the flow of water through the heat exchanger that exchanges heat with the coolant of the jacket cooling mechanism, especially the coolant.

[0293] When there is no heat exchanger for system separation, the control means or adjustment mechanism can be used for controlling or adjusting the jacket cooling temperature.

[0294] According to a further aspect, there is proposed a dry compression compressor provided with a fluid-cooled heat exchanger formed by at least one intercooler, at least one aftercooler, at least one oil cooler, and at least one device for cooling at least one compressor housing. In this regard, an individual regulating valve or control valve is provided for adjusting the water volume flow rate for each individual heat exchanger. The control or regulation of the coolant flow can be designed, for each embodiment, as the control or regulation of the volume flow rate of the respective coolant, in particular as the control or regulation of the water volume flow rate when water is used as the coolant. The temperatures of at least one intercooler, at least one aftercooler, at least one oil cooler, and at least one device for cooling at least one compressor housing (which may also be called a housing cooler) are adjusted independently of each other. This is done in particular by controlling or regulating the flow rate of the coolant through the respective cooler or device.

[0295] The mixed water outlet temperature, i.e., the outlet temperature of the total coolant flow indicated as T14 in the figure, is adjusted to a desired, in particular specified value, which is done by adjusting the water volume flow rates through the parallel-connected heat exchangers independently of each other to individual, possibly different temperatures, and thus the individual partial volume flow rates of each cooler, i.e., after the confluence of the individual coolant flows, a desired total water outlet temperature T14 is obtained. In this regard, it is proposed that the control means, in particular valves, in particular regulating valves, be controlled or regulated by a common and / or central control unit.

[0296] The following adjustments can be provided. The oil cooler always receives exactly the amount of water necessary to reach the desired oil temperature (e.g., 70 °C). The compressed air aftercooler, in particular the aftercooler or the first aftercooler, always receives exactly the amount of water necessary to not exceed the desired maximum compressed air outlet temperature, to not exceed the desired maximum pressure dew point, and to not exceed the maximum allowable water temperature (e.g., 100 °C).

[0297] The water outlet temperature from the jacket cooling mechanism, i.e., the housing cooler, is adjusted to be lower than the water outlet temperature from the intercooler.

[0298] According to a first aspect, the intercooler and the jacket cooling mechanism receive an amount of water that is necessary or less than necessary to achieve a desired mixed water outlet temperature.

[0299] According to a second aspect, the intercooler receives an amount of water that is necessary or less than necessary to achieve a desired mixed water outlet temperature T14.

[0300] It is proposed that the temperature difference between the inlet and outlet of the jacket cooling mechanism be adjusted to be approximately half the magnitude of the temperature difference between the inlet and outlet of the intercooler. The value of half the temperature difference has been demonstrated to be advantageous. In particular, this has been demonstrated as a good compromise point. However, the optimal value of the coefficient may also depend on which of the temperature differences T13 - T10, T15 - T10, and T23 - T10 are set relative to T11 - T10.

[0301] Furthermore, according to each aspect, it is proposed to maintain the mixed water outlet temperature at a predetermined or specifiable value. This value may vary depending on the outside air temperature, and for this purpose, a heating curve can be specified.

[0302] To set the flow rate, the following method steps can be provided. The method steps can be prioritized in the following order. 1. Compressed air supply, i.e., an unobstructed operation is guaranteed. 2. Compressed air quality, i.e., a specifiable pressure dew point and compressed air temperature are guaranteed. 3. Then, control or adjustment is performed so that a desired water outlet temperature T14 is achieved. 4. In some aspects, the delivery of a desired heat output is performed by a primary water system, i.e., a primary cooling circuit, and recooling by a secondary water system is provided, which can be done by a control valve, in particular the control valve V10 shown in the figure. 5. Next, control is performed so that the minimum power consumption of the compressor is achieved.

[0303] Furthermore, according to one aspect, when a compressed air dryer is used and measurement values regarding humidity are available, adjustment of the pressure dew point is proposed. For this purpose, the pressure dew point or the absolute humidity or the relative humidity can also be measured directly.

[0304] When using a freeze dryer, the temperature can also be measured at a cold location, from which the pressure dew point can be directly derived.

[0305] If the pressure dew point after the dryer becomes too high, at least one of the heat exchangers in front of the dryer, i.e., the compressed gas cooler arranged upstream of the dryer, is controlled to receive more cooling water and / or colder cooling water. In particular, the coolant flow rate through at least one compressed gas cooler is increased.

[0306] When using an adsorption dryer regenerated by the heat of the compressor, an intercooler receives less water, i.e., less coolant, in order to achieve a higher outlet temperature from the compressor, particularly from the second compressor stage, for use in regenerating the dryer.

[0307] When adjusting the water valve, in particular, the following measured temperatures are taken into account. Here, the reference signs in the figures where they are shown are appended. - The compressed air outlet temperature T100 from the compressor device. This may be, depending on the design, the compressed air outlet temperature from the last heat exchanger or the dryer, and thus may be the temperature at which the compressed gas, particularly compressed air, is discharged for further use. In this case, regarding T100, here too, depending on where the compressor device ends, one of the measured values of the temperature points T85 or T52 or T51 or T4 can be taken. - The oil temperature in the oil cooler, particularly the oil inlet temperature T60, - The oil temperature upstream of the oil cooler, - Oil outflow temperature from the compressor stage, - Air outflow temperature T51 from the aftercooler, - Air outflow temperature T31 from the intercooler, - Water outflow temperature T11 from the intercooler, - Water outflow temperature T12 from the aftercooler, - Water outflow temperatures T13, T15, T23 from the jacket cooling mechanism or the heat exchanger of the jacket cooling mechanism, - Air outflow temperature and water outflow temperature from an optional further heat exchanger 7, i.e., temperatures T52 and T25, and air outflow temperature and water outflow temperature from the heat exchanger after the dryer 8, i.e., temperatures T86 and T28, and - Air outflow temperatures T2 and T4 from the compressor stage.

[0308] According to one aspect, an embodiment of heat recovery is provided. By means of a water-water heat exchanger, the water inflow temperature T10 for the heat exchanger in the primary cooling circuit is adjusted by a control valve V10. Thereby, the heat recovery performance is set.

[0309] When the water inflow temperature T10 is low compared to the average value, the power consumption of the compressor is correspondingly somewhat lower, and since the volume flow rate of the water mass passing through the primary water circuit is smaller, the available waste heat output is significantly lower.

[0310] When the temperatures T9 and T10 are low, the waste heat output can be higher. The waste heat output is significantly lower only when T10 is lower than T9, i.e., when heat is dissipated through the heat exchanger 9 and the secondary cooling system 11.

[0311] A further aspect can be provided.

[0312] Waste heat utilization can be provided, and all the heat of the compressor can be dissipated into the primary water system (e.g., heating water). This means that depending on the heat demand and temperature profile, the waste heat from the heat exchanger can be dissipated by the primary water system. In other designs, a part of the waste heat can be dissipated by the secondary cooling system.

[0313] However, a small part of the waste heat is also dissipated by the cooling air. A further small part of the compression heat can be dissipated by the compressed air.

[0314] The recooling of the primary water (e.g., heating water) can be provided by a secondary circuit (e.g., cooling water) in the following cases. - At the site, when the heat from the primary circuit is not needed much, for example, in the connected heating device or other elements connected at the site. - To improve the specific performance and / or - When the individual components in the compressor require better cooling and the inlet temperature of the supply-side primary cooling circuit shown as T9 in the figure is too high in this regard.

[0315] According to one aspect, it is proposed that a complete internal circuit including a pump, an expansion vessel, a bypass, and optionally further elements is provided. Thereby, the compressor can operate even if it is not connected to the on-site primary water system (e.g., during a failure of the heating system).

[0316] In this aspect, water circulates only internally on the primary side through the pump 12b and the bypass 21. This aspect is shown as an example in FIG. 4.

[0317] One aspect in which a bypass V19 can be provided as a variant is shown in FIG. 8.

[0318] In this embodiment, it is proposed that the intercooler and the aftercooler together require more water than the heat exchanger arranged upstream. In an extreme case, this can occur during a cold start when the control valves V16, V13, V28, V25 are closed and the control valves V11 and V12 are open, especially fully open.

[0319] According to one embodiment, an adjustment of the jacket cooling mechanism is provided for optimal cooling. Since the jacket cooling mechanism has a significant impact on the specific performance, i.e., in particular on the performance / volume flow rate of the compressor, good cooling can thus be achieved. Here, it is proposed that the cooling should not be set too strongly in order to prevent excessive break-in of the compressor stage, especially excessive break-in of the coating between the rotor and the housing of the compressor stage.

[0320] In particular, the underlying idea here is that the cooling of the compressor stage should be as good as possible, but also as constant as possible in the long term. In the short term, as long as condensation does not occur, the colder the better.

[0321] However, this low temperature must be maintained permanently. Since this is often not possible, it may be better to cool moderately in winter and also be able to achieve this temperature in summer.

[0322] If the cooling of the stage is "too good", i.e., too strong, the housing will become smaller and the coating between the housing and the rotor will fit even better. If this continues permanently, it can be a good thing. However, if the housing or the jacket cooling mechanism then becomes hotter again later and thus larger, the gap will become larger and the performance of the compressor will deteriorate particularly.

[0323] As one aspect, it is proposed to minimize the compressed air temperature before entering the second compression stage. This temperature can be seen at the temperature measurement point T31 in FIG. 8, or can also be understood as T31. This aspect is proposed to minimize the specific performance of the compressor. For this purpose, the intercooler that cools the partially compressed air at this temperature measurement point receives as much water as possible. In this regard, coolers 7 and 8, as well as the oil cooler, are intended to receive only the necessary amount of water. This is intended to keep the preheating of the coolant small before entering the intercooler at the measurement point T19 in FIG. 8. Here, the aftercooler 4 receives as little water as possible, but the amount of water is such that the temperature at the outlet of the aftercooler 4 (measurement point T12 in FIG. 8) does not become too high. The pressure dew point and the target value regarding the optimal compressed air outflow temperature should be achieved as much as possible.

[0324] According to one aspect, it is proposed to adjust the oil temperature to a specifiable target value upstream of the oil cooler. In this regard, regarding the service life of the oil, bearings, and gearbox, the specifiable maximum temperature of the oil before the oil cooler (measurement point T60 in FIG. 7) is recognized to be more important than the injection temperature downstream of the oil cooler (measurement point T66 in FIG. 7). It has been recognized that when the heating of the oil is high, the injection temperature at the temperature measurement point T66 becomes lower. Thereby, the bearings can be cooled better even under high load or high heating. Thereby, it is possible to keep the still uncooled and thus high oil temperature constant, especially at T60, and the cooled and thus low oil temperature varies depending on the bearing load and possibly other loads, especially at T66.

[0325] The present invention can further refer to the following aspects that differentiate at least its aspects from the prior art, and these have been recognized according to the present invention.

[0326] The jacket cooling mechanism must be cooled as well and as uniformly as possible, or it must be cooled. The optimum is a constant good cooling permanently. However, in practice, usually the water temperature fluctuates greatly.

[0327] Therefore, some solutions from the prior art (see Patent Document 1) are to cool the jacket cooling mechanism by connecting it in series with an oil cooler with preheated water, to avoid the compressor housing being cooled too strongly and thus becoming too small. Strong cooling would result in an undesirable strong fit of the coating between the rotor and the housing of the compressor stage. This functional mode of fit can be seen in Patent Document 3.

[0328] Another solution according to the prior art is to cool the jacket cooling mechanism with cold (not preheated) water, but it cannot be adjusted independently. This can result in a very good specific value with cold cooling water, but it also causes a stronger fit of the coating between the rotor and the housing. Thereby, during subsequent (normal) operation at a higher water temperature, the gap becomes unnecessarily large, thereby causing more backflow, which has an adverse effect on the specific performance of the compressor.

[0329] According to the present invention, by adjusting the flow rate through the jacket cooling mechanism, it is possible to prevent the jacket cooling mechanism from being cooled too strongly when the water temperature is too low. Therefore, according to the present invention, even with non-preheated water, a more uniform and better cooling can be achieved, which permanently has a good effect on the specific performance of the compressor.

[0330] According to the present invention, in particular, the jacket cooling mechanism is cooled here with cold water instead of preheated water, and the flow rate through the jacket cooling mechanism, and thus the jacket cooling temperature T13 or the housing temperature and the housing size, are adjusted independently of other heat exchangers.

[0331] According to the present invention, it is proposed in particular to use a valve that seals. Thereby, the flow through the individual parallel lines can also be completely blocked. This applies, for example, at rest, but also during cold start. Here, water is already flowing through the intercooler and the aftercooler, but the oil cooler and the jacket cooling mechanism initially do not receive any water at all for some time until they reach their respective operating temperatures.

[0332] Therefore, a separate adjustment of the jacket cooling mechanism is one proposed aspect.

[0333] Aspects according to the present invention are further as follows.

[0334] The control or adjustment of a housing cooling mechanism, in particular a jacket cooling mechanism, separate from other cooling mechanisms is proposed, and the flow rate and / or temperature of the coolant is controlled.

[0335] Furthermore, it is proposed to control or adjust the outlet temperature of the common coolant flow, in particular of the primary cooling circuit of the compressor device. This temperature may also be called the mixed outlet temperature and is indicated in the figure at the temperature measurement point T14. It is proposed to realize the above-mentioned outlet temperature by a plurality of control means, in particular parallel adjustment mechanisms, which individually adjust to different temperatures.

[0336] According to the present invention, according to one aspect, it is recognized and proposed that, on the one hand, the jacket cooling mechanism is operated with hotter primary heat recovery water or colder secondary cooling water depending on the ratio of the current electricity tariff to the current heat tariff and the difference between the primary heat recovery temperature and the secondary cooling water temperature.

[0337] As the electricity tariff, a tariff in units of, for example, cents / kWh per kWh can be used. The above-mentioned heat tariff may depend on the gas tariff, as well as further operating costs and efficiency, or another tariff for primary energy.

[0338] Here, the underlying idea is to consider that in summer, other cheaper heat sources, especially other primary energy sources, are available.

[0339] Here, it is necessary to take into account the possibility that the waste heat from the compressor may also be costly. The higher the temperature level, the worse the specific performance [kwh / m 3 at the same time, so the waste heat cost of the compressor increases.

[0340] However, it has been recognized that the waste heat of the compressor can generally be considered much cheaper than heat generation by a gas burner.

[0341] In particular, when the heat demand is lower than the maximum possible heat supply of the compressor device, it is proposed to optimize the heat supply.

[0342] Such optimization can be achieved by reducing the temperature T10, which in turn reduces the temperature T31. Depending on the previous profile, or the gap size and temperature level of the compressor, a reduction in temperature T13 or temperature T15 may also be beneficial. Here, both are proposed as possible modes.

[0343] Both measures can reduce power consumption and at the same time increase the mass flow rate of the compressed gas, thus reducing the specific performance.

[0344] One aspect of the present invention is the adjustment of the jacket cooling mechanism. The jacket cooling mechanism exists especially in dry compression screw compressors. In oil-injected or water-injected compressors, such adjustment may not be at all or not very important. Therefore, the use of dry compression screw compressors is particularly proposed.

[0345] Turbo, scroll, rotary tooth, rotary, and reciprocating pistons can be used, which are examples of dry compression compressors.

[0346] In particular, it has been recognized that the jacket cooling mechanism has particular significance in dry compression screw compressors. Therefore, the present invention, at least in its aspects, is particularly contemplated for use in dry compression screw compressors.

Explanation of Signs

[0347] 1 First compressor stage 2 Second compressor stage 3 Intercooler 4 Aftercooler 5 Oil cooler 6 Jacket cooler heat exchanger 7 Second aftercooler 8 Third aftercooler 9 Primary-secondary heat exchanger 10 Primary heat exchanger 11 Secondary heat exchanger 12 Primary coolant pump 12a External pump 12b Internal pump 13 Secondary coolant pump 14 Jacket cooler pump 20 Adsorption dryer 21 Primary circuit bypass 30 Compressor 32 Compressor cooling circuit 34 Compressed gas line 41 First jacket cooler 42 Second jacket cooler 50, 60 Cooling water circuit 80 Secondary cooling circuit 100 Compressor device 130 Compressor 133 Intercooler 134 Aftercooler 141 First jacket cooler 142 Second jacket cooler 150 Primary cooling circuit 159 Primary regulating valve 235 Oil cooler 250 Primary cooling circuit 259 Primary regulating valve 290 Parallel line 292 Interface 300 Compressor device 341 Common jacket cooler 400 Compressor device 580 Secondary cooling circuit 900 Compressor device 901 First compressor stage 902 Housing 903 Coolant channel 904 Compressor screw 905 Drive shaft 906 Drive motor 907 Second compressor stage 908 Coolant channel 909 Housing 910 Compressor screw 911 Drive shaft 912 Gearbox K20 Condensate drainer M85 Pressure dew point temperature measurement point T1~T100 Temperature measurement points V11, V12, V13, V16 Regulating valves V14 Valve V19 Primary bypass regulating valve V25 Regulating valve V28 Regulating valve Z1, Z2 Separators

Claims

1. a compressor for compressing the gas to produce a compressed gas, in particular compressed air; A compressor apparatus comprising: an oil cooler for cooling the oil heated by the compressor; at least one compressed gas cooler for cooling the gas that has been fully or partially compressed into a compressed gas; at least one housing cooler for cooling a housing or a portion of the housing of the compressor; the oil cooler, the at least one compressed gas cooler and the at least one housing cooler are each arranged to achieve cooling by a coolant flow consisting of a fluid coolant, in particular water, a compressor arrangement in which for the coolant flow of the oil cooler, the coolant flow of at least one of the at least one compressed gas cooler and the coolant flow of at least one of the at least one housing cooler, respectively, separate control means are provided for separately controlling each of the coolant flows and thus separately controlling the cooling performance for the oil cooler, the at least one of the at least one compressed gas cooler and the at least one of the at least one housing cooler, respectively.

2. The oil cooler, the at least one compressed gas cooler, at least one of which, and the at least one housing cooler, at least one of which comprises:

2. Compressor arrangement according to claim 1, characterized in that it is connected to a common coolant circuit, in particular a primary cooling circuit, in particular in a parallel connection.

3. the compressor comprises multiple compression stages; the at least one compressed gas cooler comprises an intercooler and an aftercooler; The intercooler cools the partially compressed gas between the first compression stage and the second compression stage; the aftercooler cools the compressed gas at the outlet of the compressor after passing through the multiple compression stages; and / or 3. The compressor arrangement according to claim 1, wherein the intercooler and / or the aftercooler each have a control means capable of being controlled individually.

4. Compressor unit according to any one of claims 1 to 3, characterised in that the control means each comprise a controllable valve and / or a controllable pump.

5. The at least one housing cooler is At least one jacket cooler, which in particular comprises:

5. A compressor arrangement according to claim 1, comprising two partial jacket coolers connected in series for cooling one compressor stage each, said compressor stages being arranged to use the same cooling flow for cooling and to control said cooling flow by the same control means.

6. A common control device is provided for the coordinated control of the coolant flows, in particular A compressor arrangement according to any one of claims 1 to 5, characterised in that the common control device is arranged for controlling the control means and is connected to said control means.

7. the compressor is a dry compression compressor; and / or Compressor unit according to any one of claims 1 to 6, characterized in that it is a screw compressor arranged to compress the gas by the movement of two intermeshing screws.

8. at least one further compressed gas cooler or two further compressed gas coolers are provided, which are arranged behind the compressor in relation to a flow direction of the compressed gas and further cool the compressed gas therein; The at least one further compressed gas cooler or the two further compressed gas coolers each with a coolant flow controlled by its own individual control means; connected to a primary cooling circuit similar to or the same as the oil cooler, the at least one compressed gas cooler and / or the at least one housing cooler, in particular in a parallel connection; and / or 8. A compressor unit according to claim 1, further comprising a second medium cooling circuit as a secondary cooling circuit, said secondary cooling circuit operating separately or coupled to said primary cooling circuit, in particular via a heat exchanger.

9. The oil cooler, the at least one compressed gas cooler, and / or the at least one housing cooler each have:

9. A compressor unit according to any one of claims 1 to 8, characterized in that it comprises or is configured as a heat exchanger, and that the respective coolant flows are arranged to be controlled by the respective control means as cooling flows through the respective heat exchangers.

10. The compressor arrangements, in particular the cooling arrangements, are each provided for individually controlling the coolant flow as a function of temperature, in particular The control, the oil temperature, in particular of the oil heated by said compressor; The compressed gas temperature; a jacket temperature of the coolant flowing through the housing jacket of the compressor; and the temperature of the coolant; and an oil inlet temperature as the temperature of the oil flowing into the oil cooler; an aftercooler gas exit temperature as the temperature of the compressed gas exiting the aftercooler; the intercooler gas exit temperature as the temperature of the compressed gas exiting the intercooler; an intercooler coolant exit temperature as the temperature of the coolant exiting the intercooler; an aftercooler coolant exit temperature as the temperature of the coolant exiting the aftercooler; the jacket cooler coolant exit temperature as the temperature of the coolant exiting one or more jacket coolers; a gas or coolant exit temperature as the temperature of the compressed gas or coolant exiting, respectively, from the at least one heat exchanger; a compressor gas exit temperature as the temperature of compressed gas exiting a compressor stage of the compressor and / or the compressor and / or the compressor unit; a cooling circuit coolant exit temperature as the temperature of the coolant at the exit of the coolant from one or the primary and / or secondary cooling circuits; and / or depending on at least one temperature, in particular measured by a sensor arrangement, from the list including 10. Compressor unit according to claim 1, characterized in that the compressor unit is arranged such that at least one coolant flow is controlled depending on the pressure dew point of the compressed gas, in particular the pressure dew point measured with a sensor arrangement.

11. The compressor device, in particular the cooling device, is arranged so that the coolant flow is controlled, whereby 11. A compressor arrangement according to claim 1, characterized in that one or a certain total refrigerant outlet temperature as the temperature of the refrigerant leaving one or a primary and / or secondary cooling circuit is regulated to a specifiable target outlet temperature.

12. The compressor unit, in particular the cooling unit, the coolant flow of the oil cooler is controlled by associated control means such that a specified oil temperature is regulated; and / or and / or the coolant flow of one of the at least one compressed gas coolers, in particular one of the aftercoolers, is controlled by the associated control means so as not to exceed and / or not to fall below a specified compressed gas outlet temperature; and / or and / or the coolant flow of one of the at least one housing coolers, in particular one of the jacket coolers, is controlled such that the coolant outlet temperature of the coolant is lower than the coolant outlet temperature of one of the at least one compressed gas coolers, in particular one of the at least one intercooler; The coolant flow of one of the at least one housing coolers, in particular the jacket cooler, is such that the difference between the coolant exit temperature at the exit of the housing cooler and the coolant inlet temperature at the entry of the coolant into the housing cooler is: less than a predetermined first value, and / or exceeds a predetermined second value, and / or Between a third and fourth predetermined value So that the value of A compressor arrangement according to any one of claims 1 to 11, characterized in that it is provided.

13. 1. A method for operating a compressor arrangement, the compressor arrangement comprising: a compressor for compressing the gas to produce a compressed gas, in particular compressed air; and a cooling device, the cooling device comprising: an oil cooler for cooling the oil heated by the compressor; at least one compressed gas cooler for cooling the gas that has been fully or partially compressed into a compressed gas; at least one housing cooler for cooling a housing or a portion of the housing of the compressor; Including, said oil cooler, said at least one compressed gas cooler and said at least one housing cooler each achieve said cooling by means of a coolant flow consisting of a fluid coolant, in particular water; A method in which each coolant flow is individually controlled with a separate controllable control means such that cooling performance is individually controlled for said oil cooler, said at least one compressed gas cooler, and said at least one housing cooler.

14. 14. A method for operating a compressor arrangement according to claim 13, characterized in that a compressor arrangement according to any one of claims 1 to 12 is used.

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