Method for controlling a compressor installation and compressor installation - Patents.com

Abstract

A compressor installation having at least two compressor elements (4a, 4b, 4c), in which a last compressor element (4c) is connected to a penultimate compressor element (4b) via a pressure line (7), an outlet line (8) is connected to an outlet (6) of the last compressor element (4c), and an intercooler (9) is provided in the pressure line (7). The compressor installation (1) includes a dryer (3) for drying compressed gas, and the dryer (3) is provided with a drying section (12) connected to the outlet line (8) and a regeneration section (15). a regeneration pipe (20) branching off from a branch point (21) of an outlet pipe (8) is connected to an inlet (16) of a regeneration section (15), the compressor equipment (1) being provided with a heat exchanger (25) located in the pressure pipe (7) downstream of the intercooler (9), the compressor equipment (1) being provided with a means (29) for controlling the heat exchanger (25), and the compressor equipment (1) being provided with a control unit (31) for controlling the means (29).

Description

[Technical field]

[0001] The present invention relates to a method for controlling a compressor installation.

[0002] More specifically, the present invention aims to control a compressor installation comprising at least two compressor elements arranged in series, an outlet pipe connected to the outlet of the last of the compressor elements arranged in series, an intercooler provided between the compressor elements, the compressor installation further comprising a dryer of a type using a desiccant or desiccant for drying compressed gas emerging from the compressor installation, the dryer comprising a drying section having an inlet connected to the outlet pipe and having an outlet for dried compressed gas, and a regeneration section having an inlet and an outlet for regeneration gas, a regeneration pipe connected to the inlet of the regeneration section, the regeneration pipe being connected to the outlet pipe. [Background technology]

[0003] Such compressor installations are known, using the hot compressed gas emerging from the last compressor element for regeneration of the desiccant.

[0004] The temperature of this gas needs to be high enough to ensure sufficient regeneration of the desiccant.

[0005] Depending on the compressor components and the dryer's environmental parameters and operating conditions, the temperature of the regeneration gas may be too low to achieve proper regeneration of the desiccant.

[0006] This has the disadvantage that the next drying cycle will not be performed optimally, not only because the desiccant cannot be properly regenerated so that drying must be performed with a desiccant that still contains moisture, but also because moisture may accumulate in the dryer.

[0007] To remedy this, in some cases an electric heater is provided in the regeneration line to heat the regeneration gas, which is turned on when an unfavorable situation occurs to ensure that the temperature of the regeneration gas is increased.

[0008] This involves additional and undesirable energy consumption.

[0009] Another way to remedy this is to reduce the cooling capacity of the intercooler in these situations.

[0010] Reducing the cooling capacity of the intercooler results in a higher temperature of the compressed gas at the outlet of the last compressor element, leading to a higher temperature of the regeneration gas.

[0011] In this way, moisture accumulation in the dryer can be avoided and the desiccant is always fully regenerated.

[0012] Reducing the cooling capacity of the intercooler can be accomplished in a number of ways.

[0013] The first way is to provide a bypass line across the intercooler so that one can control how much compressed gas passes through the intercooler.

[0014] The second way is to control the flow rate of the intercooler coolant, e.g., cooling water. By flowing less refrigerant through the intercooler, the cooling capacity will be reduced.

[0015] A disadvantage of this method is that by cooling the compressed gas less or only a portion of the compressed gas, less moisture is removed.

[0016] As a result, the compressed gas at the outlet of the last compressor element, and therefore also the regeneration gas, will contain more moisture, which in turn has a detrimental effect on the regeneration of the desiccant.

[0017] In some circumstances, this may actually make regeneration worse, as opposed to a situation where the intercooler did not reduce its cooling capacity. Summary of the Invention [Problem to be solved by the invention]

[0018] The present invention aims to provide a solution to at least one of the above and other disadvantages. [Means for solving the problem]

[0019] The present invention relates to a compressor installation provided with a compressor device having at least two compressor elements arranged in series, wherein an inlet of a last compressor element of the at least two compressor elements arranged in series is connected to an outlet of a penultimate compressor element of the at least two compressor elements arranged in series via a pressure line, and an outlet line is connected to the outlet of the last compressor element of the at least two compressor elements arranged in series, and an intercooler is provided in the pressure line, and the compressor installation is further provided with a dryer of a type that uses a desiccant or desiccant for drying compressed gas generated from the compressor device, and the dryer the compressor installation is provided with a drying section having an inlet connected to the outlet pipe and having an outlet for dry compressed gas, and a regeneration section having an inlet and an outlet for regeneration gas, and a regeneration section having an inlet and an outlet for regeneration gas, the inlet of the regeneration section being connected to a regeneration pipe branching off from a branch point of the outlet pipe, the compressor installation is further provided with a heat exchanger having a primary section located in the pressure pipe downstream of the intercooler for heating the compressed gas, the apparatus is provided with a means for controlling the heating of the compressed gas by the heat exchanger, and the compressor installation is further provided with a control unit for controlling the means.

[0020] The advantage is that by providing a heat exchanger to heat the compressed gas before it enters the last compressor element, it is still possible to cool the compressed gas first to remove condensate, and the compressed gas will not have a temperature after the last compressor element that is too low as a result of this cooling to properly regenerate the desiccant.

[0021] Moreover, the cooling allows condensate to be removed so that the compressed gas after the last compressor element contains less moisture compared to existing technologies, where the compressed gas is not cooled much after the penultimate compressor element.

[0022] By providing a control unit which will control said means, the control can be automatic based on some predefined parameters.

[0023] According to a preferred feature of the invention, the secondary section of the heat exchanger is located upstream of the intercooler.

[0024] The secondary section can now be located either downstream or downstream of the penultimate compressor element.

[0025] In a practical embodiment, the secondary section of the heat exchanger is included in a bypass line on said pressure line upstream of the intercooler, said means being constituted by a control valve arranged either in the bypass line or in the part of the pressure line bypassed by the bypass line.

[0026] In another practical embodiment, the secondary section of the heat exchanger is included in said pressure line upstream of the intercooler and the primary section of the heat exchanger is bypassed via a bypass line, said means being formed by a control valve arranged either in said bypass line or in the pressure line between the intercooler and the primary section of the heat exchanger.

[0027] The advantage of such a method is that the heat exchanger can be designed smaller, since the entire flow rate of the compressed gas is used to heat the compressed gas after the intercooler, and since only a portion of the compressed gas flows through the primary section.

[0028] In a most preferred embodiment, a chiller is included downstream of the intercooler and upstream of the primary section of the heat exchanger for deep cooling of the compressed gas.

[0029] By adding a chiller, the compressed gas is cooled below ambient temperature so that additional condensate can be separated.

[0030] As a result, the compressed gas after the last compressor element, and therefore the regeneration gas, will contain less moisture, which makes the regeneration process more efficient.

[0031] The present invention relates to a method for controlling a compressor apparatus having at least two compressor elements arranged in series, in which a compressed gas is passed through a desiccant in a drying section for drying the compressed gas, and the desiccant is subsequently regenerated in a regeneration section using a regeneration gas passed through the regeneration section, the regeneration gas being branched off from the compressed gas downstream of the last of the compressor elements arranged in series, the method comprising: A) cooling compressed gas exiting a penultimate of at least two compressor elements arranged in series; B) subsequently heating the compressed gas before it enters the last of the two compressor elements arranged in series; and C) controlling the heating of the compressed gas.

[0032] The advantages of this method are similar to those of the compressor system.

[0033] By first cooling the gas, which allows condensate to be removed, and then heating the compressed gas, it is possible to ensure that the regeneration gas has a sufficiently high temperature without still having a high humidity.

[0034] Preferably, after cooling the compressed gas leaving the penultimate of the at least two compressor elements arranged in series, the method comprises the step of deep cooling the compressed gas.

[0035] This will allow more moisture to be extracted from the compressed gas so that the final regeneration gas will contain less moisture and so the regeneration will proceed better.

[0036] The present invention relates to a compressor installation provided with a compressor device having at least two compressor elements arranged in series, the inlet of the last compressor element of the at least two compressor elements arranged in series being connected via a pressure line to the outlet of the penultimate compressor element of the at least two compressor elements arranged in series, an outlet line being connected to the outlet of the last compressor element of the at least two compressor elements arranged in series, an intercooler being provided in the outlet line, and the compressor installation further comprising a dryer of a type that uses a desiccant or desiccant for drying compressed gas generated from the compressor device. the dryer is provided with a drying section having an inlet connected to the outlet pipeline and having an outlet for dried compressed gas, and a regeneration section having an inlet and an outlet for regeneration gas, and a regeneration section having an inlet and an outlet for regeneration gas, the inlet of the regeneration section being connected to a regeneration pipeline branching off from a branch point of the outlet pipeline, wherein the compressor installation is further provided with a heat exchanger included in a bypass pipeline spanning the intercooler, the compressor installation is provided with a means for controlling heating of the compressed gas by the heat exchanger, and the compressor installation is further provided with a control unit for controlling the means.

[0037] The advantage is that by providing a heat exchanger for heating at least a portion of the compressed gas before it enters the last compressor element, it is still possible to cool the remaining portion of the compressed gas first and to remove the condensate, and the compressed gas does not have a temperature after the last compressor element as a result of this cooling that is too low to be able to properly regenerate the desiccant.

[0038] Moreover, the cooling allows condensate to be removed so that the compressed gas after the last compressor element contains less moisture compared to existing technologies, where the compressed gas is not cooled much after the penultimate compressor element.

[0039] By providing a control unit which will control said means, the control can be automatic based on some predefined parameters.

[0040] In order to better illustrate the characteristics of the invention, a preferred variant of the method according to the invention for controlling a compressor installation and of a part of the compressor installation is described below by way of example and without any limiting symbols, with reference to the attached drawings, in which: [Brief description of the drawings]

[0041] [Figure 1] 1 is a diagram showing a schematic representation of a compressor device according to the present invention; [Diagram 2] FIG. 2 illustrates an alternative embodiment of the compressor unit from FIG. [Diagram 3] FIG. 2 illustrates an alternative embodiment of the compressor unit from FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The compressor installation 1 illustrated diagrammatically in FIG. 1 comprises a compressor unit 2 and a dryer 3 .

[0043] In this case, the compressor arrangement 2 comprises three compressor elements 4a, 4b, 4c arranged in series, each having an inlet 5 and an outlet 6, namely a first compressor element 4a, a penultimate compressor element 4b and a last compressor element 4c.

[0044] It is not excluded that the first compressor element 4a is absent or that there are several compressor elements 4a.

[0045] According to the invention, the inlet 5 of the last compressor element 4c is connected via a pressure line 7 to the outlet 6 of the penultimate compressor element 4b.

[0046] An outlet line 8 is connected to the outlet 6 of the last compressor element 4c.

[0047] An intercooler 9 is provided in the pressure line 7 to cool the compressed gas.

[0048] In this case, an intercooler 10 is also provided between the first and penultimate compressor elements 4a, 4b.

[0049] In this case, an aftercooler 11 is provided, although this is not essential for the invention.

[0050] Dryer 3 is of the type that uses a desiccant or desiccant to dry the compressed gas from compressor unit 2.

[0051] The dryer 3 is provided with a drying section 12 having an inlet 13 connected to the outlet line 8 and having an outlet 14 for dry compressed gas, and a regeneration section 15 having an inlet 16 and an outlet 17 for regeneration gas.

[0052] In this case, the dryer 3 is provided with a housing 18 in which the drying section 12 and the regeneration section 15 are located, and in which a drum 19 containing a desiccant is arranged, said drum 19 being connected to a drive means (not shown) such that the desiccant can be moved continuously through the drying section 12 and the regeneration section 15.

[0053] A regeneration line 20 is connected to the inlet 16 of the regeneration section 15, which branches off from the outlet line 8 at a branch point 21. This branch point 21 is located upstream of the aftercooler 11.

[0054] In this case, a return line 22 is arranged at the outlet 17 of the regeneration section 15 and connects it to the inlet 13 of the drying section 12. This connection is realised by means of a Venturi ejector 23.

[0055] In this case, a cooler 24 is provided in the return line 22 .

[0056] It will be appreciated that instead of providing a return line 22, the regeneration gas may also be discharged.

[0057] According to the invention, the compressor installation 1 is provided with a heat exchanger 25 for heating the compressed gas.

[0058] A heat exchanger primary section 26 is included in the pressure line 7 downstream of the intercooler 9 .

[0059] In this embodiment, the secondary section 27 of the heat exchanger 25 is located upstream of the intercooler 9, more specifically, the secondary section 27 of the heat exchanger 25 is included in a bypass line 28 on said pressure line 7 upstream of the intercooler 9. However, any location upstream of the intercooler 9 is possible.

[0060] In other words, the heat exchanger 25 will derive its energy from the heat of compression, although this is not essential to the invention.

[0061] According to the invention, the compressor installation 1 is provided with means 29 for controlling the heating of the compressed gas by the heat exchanger 25 .

[0062] In this particular embodiment, these means 29 are formed by a control valve 30 arranged in the part of the pressure line 7 bypassed by said bypass line 28 .

[0063] The means 29 may also be arranged in the bypass line 28 itself.

[0064] Via these means 29 it is possible to adjust how much compressed gas flows through the secondary section 27 of the heat exchanger 25, or in other words the capacity of the heat exchanger 25 can be adjusted.

[0065] The means 29 may also comprise a three-way valve arranged at the point where the bypass line 28 joins the pressure line 7 .

[0066] In the embodiment of FIG. 1, a bypass line 28 is disposed in the pressure line 7 upstream of the intercooler 9 .

[0067] It is also possible that a bypass line 28 is arranged across the intercooler 9, i.e. the compressed gas, after it has passed through the secondary section 27, is added to the delivery line 7 at a point downstream of the intercooler 9 instead of upstream of the intercooler 9, as is the case in FIG. 1 .

[0068] Furthermore, the compressor installation 1 is provided with a control unit 31 for controlling said means 29 .

[0069] Finally, the compressor installation 1 is in this case equipped with several sensors 32, 33, 34.

[0070] The term sensors 32, 33, 34 should be interpreted broadly in this context as a general "measurement means" capable of measuring or determining a certain parameter.

[0071] For that purpose, the compressor installation 1 comprises sensors 32 and 33 for determining the temperature and pressure of the compressed gas, in this case at the outlet 6 of the last compressor element 4c.

[0072] This is therefore the temperature and pressure of the regeneration gas.

[0073] In this case, a sensor 32 is provided at the outlet 6 of the last compressor element 4c, so that this sensor 32 can directly measure the temperature of the regeneration gas.

[0074] However, it cannot be excluded that a sensor 32 is arranged at the inlet 5 of the last compressor element 4 c , whereby the temperature of the regeneration gas can be calculated based on the measurement of the sensor 32 .

[0075] The compressor installation 1 also comprises a sensor 34 for measuring the temperature of the compressed gas at the inlet 13 of the drying section 12 .

[0076] A control unit 31 is connected to said sensors 32, 33, 34 and is configured to determine, based on signals from said sensors 32, 33, 34, how much moisture enters the dryer 3, i.e. the amount of moisture in the compressed gas entering the drying section 12 minus the amount of moisture in the compressed gas leaving the drying section 12, or therefore the amount of moisture absorbed by the desiccant, and how much moisture leaves the dryer 3, i.e. the amount of moisture in the regenerated gas leaving the regenerated section 15 minus the amount of moisture in the regenerated gas entering the regenerated section 15, or therefore the amount of moisture extracted from the desiccant, and based on this to operate the means 29. This will be explained in more detail below.

[0077] In principle, the sensors 33 and 34 are optional, i.e. they are not essential for controlling the means 29. However, the provision of one or both of these sensors 33, 34 leads to a more accurate control.

[0078] The operation of the compressor installation 1 is very simple and is as follows.

[0079] Compressor elements 4a, 4b, 4c will compress a gas, for example ambient air.

[0080] After the first compressor element 4a, the compressed gas passes through an intercooler 10 to cool the gas and separate the condensate.

[0081] After the penultimate compressor element 4 b , a portion of the compressed gas is branched off and directed to the secondary section 27 of the heat exchanger 25 and then rejoins the compressed gas for further direction to the intercooler 9 .

[0082] The compressed gas is cooled in this intercooler 9 where the condensate can be separated.

[0083] After passing through the intercooler 9, the compressed gas passes to the primary section 26 of the heat exchanger 25 where it is reheated.

[0084] In this case, the heat of the compressed gas upstream of the respective intercooler 9 is used to reheat the compressed gas, although it is not excluded that the heat of the compressed gas from upstream of the penultimate compressor element 4b is used or that another heat source is used.

[0085] The reheated compressed gas is then passed to the final compressor element 4c.

[0086] Thereafter, a portion of the compressed gas is branched off as regeneration gas through regeneration line 20 and directed to regeneration section 15 to extract moisture from the desiccant, while the remainder of the compressed gas is passed through aftercooler 11 to the inlet 13 of drying section 12.

[0087] After passing through the regeneration section, the now moist regeneration gas is returned via return line 22 to the inlet 13 of the drying section 12 .

[0088] The compressed gas continues through a drying section 12 and the dry compressed gas exits the compressor unit 1 through an outlet 14 .

[0089] A control valve 30 is controlled by a control unit 31 to control how much compressed gas is directed to the secondary section 27 of the heat exchanger 25 after the penultimate compressor element 4b.

[0090] By directing more compressed gas to the heat exchanger 25, the compressed gas is heated more, so that the compressed gas after the last compressor element 4c and therefore also the regeneration gas will have a higher temperature, resulting in a more optimal or better proceeding regeneration of the desiccant. In other words, the heating of the compressed gas and the temperature of the regeneration gas can be controlled by controlling the control valve 30.

[0091] The control unit 31 will determine what temperature of the regeneration gas is required.

[0092] For this purpose, the control unit 31 will determine how much moisture enters the dryer 3, i.e. the amount of moisture in the compressed gas entering the drying section 12 minus the amount of moisture in the compressed gas leaving the drying section 12, or therefore the amount of moisture absorbed by the desiccant, and how much moisture leaves the dryer 3, i.e. the amount of moisture in the regeneration gas leaving the regeneration section 15 minus the amount of moisture in the regeneration gas entering the regeneration section 15, or therefore the amount of moisture drawn off from the desiccant.

[0093] The control unit 31 will now use signals from the above sensors 32, 33, 34. It is also possible for the control unit 31 to determine this differently, for example by using other sensors and / or sensors in other locations.

[0094] The control unit 31 will set the temperature of the regeneration gas such that the moisture entering the dryer 3 is equal to the moisture leaving the dryer 3 or within a certain margin.

[0095] If there is too little moisture leaving the dryer 3, the control unit 31 will increase the temperature of the regeneration gas by appropriately adjusting the control valve 30. The regeneration of the saturated desiccant will proceed better, allowing more moisture to be extracted from the desiccant.

[0096] In this way it can be ensured that little or no moisture remains in the dryer 3. This in turn ensures the proper functioning of the dryer.

[0097] FIG. 2 illustrates a variant according to FIG. 1, in which the dryer 3 first comprises several containers 35 filled with desiccant, of which at least one container 35 constitutes the drying section 12 and at least one container 35 constitutes the regeneration section 15.

[0098] In this case there are two vessels 35 , one of which constitutes the drying section 12 and the other the regeneration section 15 .

[0099] The dryer 3 further comprises a valve mechanism 36 connecting the inlets 13 and 16, respectively, and the outlets 14 and 17, respectively, of the drying section 12 and of the regeneration section 15 to said vessels 35, said valve mechanism 36 being such that at least one vessel 35 is always being regenerated while the other vessels 35 dry the compressed gas, and by controlling the valve mechanism 36, the vessels 35 are regenerated successively, one after the other.

[0100] Moreover, in this case the secondary section 27 is comprised in the pressure line 7 itself, upstream of the intercooler 9 .

[0101] The primary section 26 of the heat exchanger 25 is in this case bypassed via a bypass line 37 .

[0102] Said means 29 are formed by a control valve 30 arranged in the pressure line 7 between the intercooler 9 and the primary section 26 of the heat exchanger 25 .

[0103] However, said means 29 can also be arranged in said bypass line 37 .

[0104] Finally, the compressor installation 1 is provided with a chiller 38 downstream of the intercooler 9 and upstream of the primary section 26 of the heat exchanger 25 for deep cooling of the compressed gas.

[0105] The operation of the device 1 of FIG. 2 is very similar to that of FIG.

[0106] In this case, the compressed gas would be passed after the intercooler 9 to a chiller 38 where it is further cooled to below ambient temperature.

[0107] As a result, more water will condense and the compressed gas will be drier.

[0108] After the intercooler 9, a portion of the gas is passed through a heat exchanger 25 and heated using the heat of compression after the penultimate compressor element.

[0109] By controlling the control valve 30, it is possible to control how much gas is heated and how much gas is directed directly to the last compressor element 4c via the bypass line 37, and therefore the temperature of the compressed gas entering the last compressor element 4c, and therefore also the temperature of the regeneration gas.

[0110] The control unit 31 will also apply the control as described above in this embodiment.

[0111] FIG. 3 illustrates a second alternative embodiment of FIG. 1, in which, instead of bypass line 28, a bypass line 39 is provided.

[0112] The heat exchanger 25 is provided in a bypass line 39 , and its primary section 26 is included in the bypass line 39 .

[0113] Furthermore, means 29 are provided in the form of a control valve 30 for controlling how much compressed gas passes through the intercooler 9 .

[0114] The compressor installation 1 is also provided with means 40 for separating the condensate, said means 40 being located downstream of the intercooler 9.

[0115] These means 40 are in this case condensate separators.

[0116] Otherwise the apparatus is the same as that shown in FIG.

[0117] The operation of this embodiment is similar to that described above, however, in this case, control is exercised over which portions of the compressed gas are cooled and which are heated.

[0118] The embodiments of Figures 1 and 2 may also be provided with a condensate separator 40. In Figure 1, this condensate separator 40 is preferably located downstream of the intercooler 9 and upstream of the primary section 26. In Figure 2, it is preferably downstream of the chiller 38 and upstream of the primary section 26 and the bypass line 37.

[0119] The invention is in no way limited to the embodiments described by way of example and illustrated in the figures, but such a method for controlling a compressor installation and a compressor installation can be realised according to various variants without departing from the scope of the invention. [Explanation of symbols]

[0120] 1 Compressor equipment 2 Compressor unit 3 Dryer 4a, 4b, 4c Compressor elements 5 entrance 6 exit 7 Pressure Pipeline 8 Outlet pipe 9 Intercooler 10 Intercooler 11 Rear cooler 12 Dry Section 13 Entrance 14 Exit 15 Playback section 16 Entrance 17 Exit 18 Housing 19 Drums 20 Regeneration pipeline 21 Branching Point 22 Return Pipe 23 Venturi ejector 24 Cooler 25 Heat exchanger 26 Primary Section 27 Secondary Section 28 Bypass Pipe 29 means 30 Control valve 31 Control Unit 32, 33, 34 Sensors 35 Container 36 Valve mechanism 37 Bypass Pipe 38 Chiller 39 Bypass Pipe 40 Means, condensate separator

Claims

1. a compressor installation provided with a compressor arrangement (2) having at least two compressor elements (4a, 4b, 4c) arranged in series, the inlet (5) of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series being connected via a pressure line (7) to the outlet (6) of the penultimate compressor element (4b) of the at least two compressor elements (4a, 4b, 4c) arranged in series, an outlet line (8) being connected to the outlet (6) of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series, the pressure line (7) being provided with an intercooler (9), the compressor installation (1) further being provided with a dryer (3) of the type using a desiccant or desiccant for drying the compressed gas emerging from the compressor arrangement (2), the dryer (3) being provided with a drying section (12) having an inlet (13) connected to the outlet pipe (8) and having an outlet (14) for dry compressed gas, and a regeneration section (15) having an inlet (16) and an outlet (17) for regeneration gas, the inlet (16) of the regeneration section (15) being connected to a regeneration pipe (20) branching off from a branch point (21) of the outlet pipe (8), characterized in that the compressor installation (1) is further provided with a heat exchanger (25) having a primary section (26) located in the pressure pipe (7) downstream of the intercooler (9) for heating the compressed gas, the compressor installation (1) is provided with means (29) for controlling the heating of the compressed gas by the heat exchanger (25), and the compressor installation (1) is further provided with a control unit (31) for controlling the means (29).

2. A compressor installation according to claim 1, characterized in that the secondary section (27) of the heat exchanger (25) is located upstream of the intercooler (9).

3. A compressor installation according to claim 2, characterized in that the secondary section (27) of the heat exchanger (25) is included in a bypass line (28) on the pressure line (7) upstream of the intercooler (9).

4. A compressor installation according to claim 1, characterized in that the secondary section (27) of the heat exchanger (25) is included in a bypass line (28) on the pressure line (7) arranged across the intercooler (9).

5. said means (29) a control valve (30) arranged either in said bypass line (28) or in the section of said pressure line (7) bypassed by said bypass line (28), A compressor installation according to claim 3 or 4, characterized in that the bypass line (28) is formed by a three-way valve arranged at the junction with the pressure line (7).

6. 3. A compressor installation according to claim 2, characterized in that the secondary section (27) of the heat exchanger (25) is included in the pressure line (7) upstream of the intercooler (9) and the primary section (26) of the heat exchanger (25) is bypassed via a bypass line (37), and in that the means (29) are formed by a control valve (30) arranged either in the bypass line (37) or in the pressure line (7) between the intercooler (9) and the primary section (26) of the heat exchanger.

7. A compressor installation according to any one of claims 1 to 6, characterized in that it comprises a chiller (38) downstream of the intercooler (9) and upstream of the primary section (26) of the heat exchanger (25) for deep cooling of the compressed gas.

8. A compressor installation according to any one of claims 1 to 7, characterized in that the compressor installation (1) is provided with means (40) for separating condensate, said means (40) being located downstream of the intercooler (9).

9. A compressor installation according to any one of claims 1 to 8, characterized in that the dryer (3) is provided with a housing (18) inside which the drying section (12) and the regeneration section (15) are located, and in which a drum (19) containing the desiccant is arranged, the drum (19) being connected to drive means so as to be able to move the desiccant continuously through the drying section (12) and the regeneration section (15).

10. A compressor installation according to any one of claims 1 to 8, characterized in that the dryer (3) comprises several containers (35) filled with the desiccant, of which at least one container (35) constitutes the drying section (12) and at least one container (35) constitutes the regeneration section (15), the dryer (3) further comprising a valve mechanism (36) connecting the inlets (13 and 16, respectively) and outlets (14 and 17, respectively) of the drying section (12) and of the regeneration section (15) to the containers (35), the valve mechanism (36) being such that at least one container (35) is always regenerated, while the other containers (35) dry the compressed gas, whereby by adjusting the valve mechanism (36) the containers (35) are regenerated successively, one after the other.

11. A compressor installation according to any one of claims 1 to 10, characterized in that a return line (22) is arranged at the outlet (17) of the regeneration section (15) and connects it to the inlet (13) of the drying section (12).

12. A compressor installation according to any one of claims 1 to 11, characterized in that an aftercooler (11) is arranged in the outlet line (8) downstream of the branch point (21) of the regeneration line (20).

13. A compressor installation according to any one of claims 1 to 12, characterized in that the compressor installation (1) is further provided with a sensor (32) for determining, measuring or calculating the temperature of the compressed gas at the outlet (6) of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series, and the control unit (31) is configured to determine, based on a signal from the sensor (32), how much moisture enters the dryer (3) and how much moisture leaves the dryer, and to control the means (29) accordingly.

14. A compressor installation according to claim 13, characterized in that the compressor installation is additionally provided with a sensor (34) for measuring the temperature of the compressed gas at the inlet (13) of the drying section (12) and / or a sensor (33) for determining the pressure of the compressed gas at the outlet (6) of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series, and the control unit (31) is configured to determine, based on signals from the sensors (32, 33 and / or 34), how much moisture enters the dryer (3) and how much moisture leaves it, and to control the means (29) accordingly.

15. A method for controlling a compressor arrangement (2) having at least two compressor elements (4a, 4b, 4c) arranged in series, in which in a drying section (12) for drying the compressed gas, the compressed gas is passed through a desiccant, which is subsequently regenerated in a regeneration section (15) using a regeneration gas passed through the regeneration section (15), the regeneration gas being branched off from the compressed gas downstream of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series, A) cooling the compressed gas leaving the penultimate compressor element (4b) of the at least two compressor elements (4a, 4b, 4c) arranged in series; B) subsequently heating the compressed gas before it enters the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series; C) controlling the heating of the compressed gas.

16. A method according to claim 15, characterized in that for heating the compressed gas, heat of the compressed gas upstream of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series is used.

17. A method according to claim 15 or 16, characterized in that the step of controlling the heating of the compressed gas consists of determining how much moisture enters the dryer (3) and how much moisture leaves the dryer (3) and controlling the temperature of the compressed gas based thereon.

18. A method according to any one of claims 15 to 17, characterized in that a heat exchanger (25) is used to heat the compressed gas.

19. Method according to any one of claims 15 to 18, characterized in that, after cooling the compressed gas leaving the penultimate compressor element (4b) of the at least two compressor elements (4a, 4b, 4c) arranged in series, the method comprises a step of deep cooling the compressed gas.

20. a compressor installation provided with a compressor arrangement (2) having at least two compressor elements (4a, 4b, 4c) arranged in series, the inlet (5) of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series being connected via a pressure line (7) to the outlet (6) of the penultimate compressor element (4b) of the at least two compressor elements (4a, 4b, 4c) arranged in series, an outlet line (8) being connected to the outlet (6) of the last compressor element (4c) of the at least two compressor elements (4a, 4b, 4c) arranged in series, the pressure line (7) being provided with an intercooler (9), the compressor installation (1) further being provided with a dryer (3) of the type using a desiccant or desiccant for drying the compressed gas emerging from the compressor arrangement (2); the dryer (3) is provided with a drying section (12) having an inlet (13) connected to the outlet pipe (8) and having an outlet (14) for dried compressed gas, and a regeneration section (15) having an inlet (16) and an outlet (17) for regeneration gas, and a regeneration pipe (20) branching off from a branch point (21) of the outlet pipe (8) is connected to the inlet (16) of the regeneration section (15), characterized in that the compressor installation (1) is further provided with a heat exchanger (25) included in a bypass pipe (39) spanning the intercooler (9), the compressor installation (1) is provided with a means (29) for controlling heating of the compressed gas by the heat exchanger (25), and the compressor installation (1) is further provided with a control unit (31) for controlling the means (29).

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