Apparatus and method for degassing a device and corresponding test system for gas analysis

Abstract

To degas the device (7), an apparatus (10) is provided, comprising a control unit (19), a pump (3), a first volume (1, 2), a second volume (6), a valve device (12), a first valve (15), and a second valve (14). At the discharge end, the pump (3) is connected to the outlet (21) via the valve device (12) and to the first volume (1, 2) via the valve device (12). The first volume (1, 2) and the second volume (6) are connected to each other via the first valve (15). At the suction end, the pump (3) is connected to the first volume (1, 2) via the second valve (14) and can be connected to the device (7) to be degassed.

Description

Technical Field

[0001] The present invention relates to an apparatus and method for degassing a device, wherein the dead zone volume fraction is reduced, for example, to enable better analysis of dissolved gases. Background Technology

[0002] For example, in determining the condition and identifying errors in oil-paper insulated power transformers, analyzing gases dissolved in the insulating oil (Dissolved Gas Analysis, DGA) is an important method. Before analysis, the gas to be analyzed must be separated from the insulating oil (e.g., degassing), a process known as degassing. This degassing can be performed using various methods. Complete degassing under vacuum achieves the highest extraction rate.

[0003] For example, the lower the pressure in the container or volume containing the gas, the more effective the gas extraction from the insulating oil. The lower the pressure difference between the pump inlet and the pump outlet, the more effective the degassing pump for this gas extraction. Therefore, according to existing technology, the volume at the pump outlet is selected so that the pressure in that volume does not rise too high during degassing or extraction.

[0004] To address this, the components of the degassing unit can be emptied using a pump used for degassing. However, a problem exists here: the ambient pressure present at the pump outlet and in the piping away from it causes air in the so-called dead zone volume to contaminate the degassing unit after it switches from emptying to degassing. For example, a dead zone volume of 100 µl in a 10 ml total volume can result in nitrogen contamination of nearly 7000 ppm, making nitrogen measurements difficult in the low ppm range. Summary of the Invention

[0005] Therefore, the objective of this invention is to reduce contamination of gases (especially air) located in dead zones compared to existing technologies. In doing so, the method for solving this problem should be as inexpensive as possible and require as little space as possible.

[0006] According to the invention, this task is accomplished by the apparatus for degassing the equipment according to claim 1, the testing system according to claim 13, and the method for degassing the equipment according to claim 14. The dependent claims define preferred and / or advantageous embodiments of the invention.

[0007] Within the framework of this invention, an apparatus for degassing a device (particularly a degassing container) is provided. The apparatus includes a control unit, a pump, a first volume or container, a second volume or container, a valve device, a first valve, and a second valve. The valve device can include a three-way valve or two valves. The pump is connected to an outlet via the valve device, through which the device to be degassed is vented, for example. On the other hand, at the discharge end, the pump is connected to the first volume via the valve device to pump gas, for example, from the device to be degassed, into the first volume. The first and second volumes are interconnected via the first valve, such that, depending on the state of the first valve (open or closed), the first volume is connected to the second volume or the two volumes are separated. At the intake end, the pump is connected to the first volume via the second valve, such that when the second valve (and the first valve) is open, the pump (e.g., during discharge) can pump gas from the second volume. At the intake end, the pump can be connected to the device to be degassed, such that when the pump is connected to the device, the pump can pump gas away from the device or pump gas out of the device.

[0008] This device advantageously allows the pump to be used in conjunction with gas extraction or degassing for evacuation equipment (e.g., degassing containers) and for evacuating both the first and second volumes. During evacuation, the second volume is also evacuated to a very low pressure (e.g., 0.1 mbar). If, after evacuation, the first volume and the second volume connected to it are connected at the pump's discharge point, the air in the dead zone volume will be distributed into the total volume formed by the dead zone volume, the first volume, and the second volume. The large second volume results in a significantly lower amount of contaminated air present in the first volume compared to a device without a second volume. In a broader sense, compared to a conventional device without a second volume, a second volume with a volume content X times larger than the first volume will reduce contamination of the first volume by X times due to air in the dead zone volume. For degassing after evacuation, the second volume is disconnected from the first volume via a first valve.

[0009] Since contamination caused by air in the dead zone volume can be greatly reduced, the present invention can advantageously and extremely simply examine oxygen and nitrogen (substances also present in the dead zone volume) in insulating oil with good analytical results compared to the prior art, because the gases being examined are not affected by substances in the dead zone volume.

[0010] The volume content of the second volume is preferably at least ten times that of the first volume, more preferably at least 100 times, and even more preferably at least 1000 times.

[0011] Advantageously, the larger the second volume is relative to the first volume, the less pollution is caused by the air in the dead zone volume in the first volume.

[0012] The second volume, also known as a gas cylinder, can be implemented using a convenient cylinder. Furthermore, the second volume or gas cylinder can be placed at any desired location within the device. Any longer pipe leading to the second volume will only increase its volume, thereby advantageously enhancing the effect of reducing air pollution caused by the dead zone volume.

[0013] In addition, the device can be advantageously designed to minimize the dead zone volume, for example by minimizing the distance between the pump outlet and the valve device.

[0014] According to an embodiment of the invention, with the assistance of the device's control unit, the device switches a valve device such that the valve device connects the pump's outlet to the gas outlet only. Furthermore, with the assistance of the device's control unit, the device opens the first valve and the second valve. After the valve device connects the pump's outlet to the gas outlet only, the control unit activates the pump to pump gas from the equipment connected to the device and pump out the first and second volumes, thereby evacuating the equipment, the first volume, and the second volume.

[0015] Because the valve device connects the pump's outlet only to the outlet (and not yet to the first volume) and the first and second valves are open, the pump is advantageously able to efficiently evacuate the equipment connected to the device, as well as the first and second volumes, in one process (i.e., without changing valves).

[0016] According to an embodiment of the invention, with the assistance of the device's control unit, the device switches a valve device such that the valve device directly connects the pump's outlet only to the first volume. Furthermore, with the assistance of the device's control unit, the device opens the first valve and the second valve, thereby creating pressure equalization in the total volume comprising the first volume, the second volume, and the dead zone volume.

[0017] Because the first and second volumes are interconnected via a first valve during pressure equalization, it is advantageous that the air present in the dead zone volume is distributed not only in the first volume but also in the larger second volume. As a result, the contamination in the first volume is significantly lower compared to existing technologies that do not have a second volume.

[0018] According to an embodiment of the invention, with the assistance of the device's control unit, the device switches a valve device such that the valve device directly connects the pump's outlet only to the first volume. Furthermore, by means of the device's control unit, the device closes the first valve and the second valve. After the first and second valves are closed, the control unit activates the pump to pump gas from the device into the first volume.

[0019] Because the pump is connected to the first volume only at the discharge end valve device, and both the first and second valves are closed, the device can also be advantageously used to degas gas from a device (e.g., a degassing container) into the first volume via the pump. Therefore, it is advantageous to use the same pump for both venting and degassing.

[0020] According to an embodiment of the invention, the device includes a third valve. The device to be degassed is connected to the pump inlet via the third valve.

[0021] The third valve allows the device to be permanently connected (via the third valve) to the equipment to be degassed. The third valve facilitates easy control of the purging, pressure equalization, and degasing processes. During the purging and degasing processes, the third valve is opened, allowing the pump to remove gas from the equipment. Conversely, during pressure equalization and potential compression processes (see below), the third valve is closed, as detailed below.

[0022] According to an embodiment of the invention, by means of a control unit, the device switches a valve device such that the valve device connects the pump's outlet only to the gas outlet. Furthermore, the control unit opens the first, second, and third valves. After the first, second, and third valves are opened, the control unit activates the pump, resulting in the pump pumping gas out of the device, the first volume, and the second volume, thereby emptying the device, the first volume, and the second volume.

[0023] Since the pump's outlet is connected only to the air outlet, and the first to third valves are open, it is advantageous that the pump can empty the equipment to be degassed, as well as the first and second volumes, in one step.

[0024] According to an embodiment of the invention, with the assistance of the device's control unit, the device switches valve devices such that the pump is directly connected to the first volume only through its outlet. Furthermore, the control unit opens the first and second valves and closes the third valve. Once the first and second valves are open and the third valve is closed, pressure equalization is achieved in the total volume comprising the first volume, the second volume, and the dead zone volume.

[0025] Since the first volume, the second volume, and the dead zone volume form a total volume during pressure equalization, the air present in the dead zone volume will be advantageously distributed within this total volume. Therefore, advantageously, compared to conventional devices without a second volume, the contamination caused by air in the dead zone volume in the first volume is significantly lower.

[0026] According to an embodiment of the invention, by means of a control unit, the device switches a valve device such that the valve device directly connects the pump outlet only to the first volume. Furthermore, by means of the control unit, the first and second valves are closed and the third valve is opened. After the first and second valves are closed and the third valve is open, the control unit activates the pump, causing the pump to pump gas from the device into the first volume.

[0027] Because the valve device connects the pump to the first volume only at the discharge end, and the first and second valves are closed, gas is either degassed from the device to be degassed or pumped into the first volume only through the open third valve. Therefore, it is advantageous that the same pump can be used not only for venting equipment and devices but also for degassing.

[0028] According to an embodiment of the invention, the device further includes a sensor. The sensor is at least partially arranged within the first volume and is designed to analyze the gas in the first volume.

[0029] With the aid of a sensor, after degassing, the gas in the first volume can be analyzed in a nearly automated manner. This sensor measures the gas. The sensor can be a semiconductor sensor, an optical sensor (or optical measuring device), a thermal conductivity sensor, or a chemical analysis device (e.g., a gas chromatograph). In other words, the sensor can be any device capable of measuring gases, where these gases are required to have the highest possible (absolute) concentration.

[0030] According to an embodiment of the invention, the first volume comprises a first partial volume and a second partial volume. The first partial volume is connected to the second partial volume via an additional valve of the device. By means of a control unit, the valve devices are switched such that they connect the pump outlet directly to either the first volume or the first partial volume. Furthermore, the control device closes the first valve, the third valve, and the additional valve while opening the second valve. After the first valve, the third valve, and the additional valve are closed and the second valve is open, the pump is activated by the control unit so that gas is subsequently pumped from the second partial volume into the first partial volume. As a result, the gas being degassed from the device to be degassed is advantageously compressed in the first partial volume, thus facilitating gas analysis.

[0031] In this embodiment, the auxiliary valve is advantageously opened during the degassing step, allowing gas to be pumped from the device to be degassed into both the first and second partial volumes. In the subsequent compression step, the auxiliary valve closes, leaving only one connection between the first and second partial volumes via the pump. As a result, during the compression step, the pump can pump gas from the second partial volume (low-pressure volume) into the first partial volume (high-pressure volume) to increase the pressure there. The higher pressure increases the gas concentration in the first partial volume, which is beneficial for subsequent analysis of these gases.

[0032] The apparatus according to the invention advantageously allows the extractable gas to be pumped or delivered to both partial volumes during degassing, such that the pressure on the pump's discharge side increases only slightly. After degassing, the same pump can pump the extractable gas from the second partial volume into the first partial volume, resulting in an increase in the pressure of the extractable gas in the first partial volume.

[0033] The second volume or low-pressure volume is preferably at least five times larger than the first volume or high-pressure volume, more preferably ten times larger, or even 20 times larger. However, it is also possible (depending on the amount of gas present and the amount of gas on the pump) for the second volume or low-pressure volume to be 100 times or even 1000 times larger than the first volume or high-pressure volume.

[0034] According to this embodiment, the high-pressure volume is significantly smaller than the low-pressure volume. The low-pressure volume is advantageously chosen such that the pressure at the pump discharge end does not rise during degassing, thereby impairing pump efficiency.

[0035] In the exemplary application, only a small amount of gas (approximately 1 ml) is available. In this case, the size of the first volume (high-pressure volume) can be 0.5 ml and the size of the second volume (low-pressure volume) can be 10 ml.

[0036] The absolute size of the fractional volume typically depends on the amount of gas to be measured or that can be measured (i.e., available). The absolute size of the fractional volume also depends on the sensor used (for analyzing the gas). Of course, the volume could be in the µl range (i.e., significantly less than 1 ml). On the other hand, it is also possible to generate several liters of gas (e.g., during emission measurement) and then choose a correspondingly larger fractional volume (ranging from 1 L to 20 L).

[0037] The ratio between the gas volume (the volume of the gas to be analyzed or the degassed volume) and the first and second part volumes is generally similar. The second part volume (low-pressure volume) is usually chosen to be equal to or greater than the gas volume, while the first part volume (high-pressure volume) is significantly smaller. This ratio can depend on the pump used. For example, when using a high-pressure pump, the second part volume (low-pressure volume) may be only, for example, one-tenth of the gas volume. In this case, the second part volume will therefore be smaller than the gas volume.

[0038] Within the framework of this invention, a testing system is also provided for testing one or more gases dissolved in or at equipment (such as high-voltage equipment). According to the invention, the testing system includes an evaluation unit and a degassing device as described above. The testing system is designed to analyze gases inside or from the equipment (e.g., analyze gases dissolved in the insulating oil of high-voltage equipment). The evaluation unit is designed to analyze the gas pumped into a first volume (e.g., with the assistance of sensors in the device), and based on this analysis, plot and advantageously output the test results of the equipment.

[0039] The testing system according to the invention can be used in a similar manner to the apparatus according to the invention on oil-insulated high-voltage equipment, such as power transformers, current transformers, voltage transformers, and gas-insulated switchgear. The gas to be analyzed can be a gas used to insulate the high-voltage equipment itself, or a gas that has been released from the insulating components or the liquid insulating oil.

[0040] Finally, within the framework of this invention, a method for degassing a device is provided. This method includes the following steps:

[0041] • Connect the first volume to a second volume that can be disconnected from the first volume. For example, this step can be performed by opening a valve between the first and second volumes.

[0042] • Evacuate the device together with the first and second volumes. In this step, the device to be degassed, as well as the first and second volumes, are specifically interconnected by open valves, so that the same pump can evacuate the device to be degassed together with the first and second volumes in one step without any changes to the settings (e.g., changing the settings of certain valves or valve devices).

[0043] • Disconnect the device to be degassed from the first and second volumes. For example, this step can be performed automatically by closing a valve through which the device to be degassed is connected to the apparatus.

[0044] • Pressure equalization is performed in the total volume, which includes the first volume, the second volume, and the dead zone volume. Advantageously, in this step, the first or second volume is not connected to the outside environment. This can be achieved, for example, by switching the aforementioned valve devices so that neither the pump outlet nor the first volume is connected to the outlet via valve devices.

[0045] • Separate the second volume from the first volume. For this purpose, it is preferable to close the valve connecting the first and second volumes.

[0046] • The equipment is degassed in the first volume. In this step, gas is pumped from the equipment to be degassed into the first volume using a pump.

[0047] A key step in the method described above is the pressure equalization step. In this step, the air in the dead zone volume is distributed to the first and second volumes. Because the second volume actually exists and is significantly larger than the first volume, the degree of contamination of the gas in the first volume by the gas in the dead zone volume is significantly less than the degree if the second volume were not present.

[0048] Furthermore, the advantages of the method according to the invention substantially correspond to the advantages of the apparatus according to the invention, which have already been described above, and therefore we will avoid repeating them here.

[0049] Specifically, the device to be degassed is a degassed container into which the liquid to be degassed (e.g., oil) is filled (e.g., manually). However, it is also possible that a manual process is not required, for example, by automatically filling (pumping) the liquid to be degassed into the degassed container, or by introducing gas into the device or test system according to the invention and obtaining the gas to be analyzed directly from the equipment (e.g., high-voltage equipment). In the latter case, the device to be degassed corresponds almost entirely to the equipment. Therefore, the device can be designed to degassed the insulating fluid (e.g., oil) of high-voltage equipment.

[0050] Besides inspecting high-pressure equipment, this invention can also be used with gas measuring equipment. Therefore, this invention can be used for quality control in laboratories, for process analysis and monitoring in the following scenarios:

[0051] • Petrochemical and chemical plants;

[0052] • Natural gas processing plant;

[0053] • Biogas plant;

[0054] • Online natural gas analysis and determination of higher calorific value in energy production;

[0055] • Emissions measurement. Attached Figure Description

[0056] The present invention will now be described in more detail using preferred embodiments and with reference to the accompanying drawings.

[0057] Figure 1 An apparatus according to the invention is schematically depicted, which is connected to a degassing container to be degassed.

[0058] Figure 2 A test system connected to the high-voltage equipment under test is illustrated schematically. Detailed Implementation

[0059] Figure 1The device 10 according to the invention is schematically depicted, which is connected to the device to be degassed (here, the degassed volume or degassed container 7).

[0060] The device includes a three-way valve 12, a first valve 15, a second valve 14, a third valve 11, an auxiliary valve 13, a pump 3, a first volume comprising a sensor container or first partial volume 1 and an expansion container or second partial volume 2, a gas tank or second volume 6, and a sensor 4 disposed in the first volume, more specifically, in the first partial volume 1 (analysis volume). The first valve 15 is disposed between the first volume (more precisely, the second partial volume 2) and the second volume 6. The pump 3 is arranged such that it is connected at the suction end to the first volume (more precisely, the second partial volume 2) via the second valve 14 and / or to the degassing container 7 via the third valve 11. The pump 3 can be connected at the discharge end to the outlet 21 or the first volume (more precisely, the first partial volume 1) via the three-way valve 12. The auxiliary valve 13 is disposed between the first partial volume 1 (analysis volume) and the second partial volume 2 (expansion volume).

[0061] The apparatus 10 is designed to minimize the dead zone volume 22 (the volume within the piping from the outlet of pump 3 to the inlet of three-way valve 12). The volume of the gas tank 6 is specifically determined by the sum of the dead zone volume 22, the analysis volume 1, and the expansion volume 2, but is generally also limited by the largest practically possible structural shape. In principle, the following rule applies: the larger the volumetric content of the gas tank 6, the better. For example, the volumetric content of the degassing volume can be approximately 300 ml (approximately 700 ml) (depending on the degassing container 7 used), the volumetric content of the expansion volume 2 can be approximately 10 ml, the volumetric content of the analysis volume 1 can be approximately 500 µl, and the volumetric content of the gas tank 6 can be approximately 750 ml (approximately 1.5 l).

[0062] The following will utilize Figure 1 The depicted apparatus 10 is used to explain the steps from venting to gas analysis performed according to an embodiment of the invention.

[0063] First, in the connection step, the first volumes 1 and 2 are connected to the second volume 6 by opening the first valve 15. Alternatively, the result of this connection step (i.e., the opening of the first valve 15) can be effectively defined as a prerequisite for the subsequent evacuation step.

[0064] During the purging step, device 10 and degassing container 7 are purged. Three-way valve 12 is switched so that it connects the outlet of pump 3 only to outlet 21. First valve 15, second valve 14, third valve 11, and auxiliary valve 13 are opened. As a result, pump 3 pumps air or gas from the first volumes 1, 2, second volume 6, and degassing container 7 and pumps it out of device 10 and degassing container 7 via outlet 21. At the end of the purging step or purging phase, degassing container 7, first volumes 1, 2, and second volume 6 have a pressure of, for example, 0.1 mbar, while the portion of device 10 from the outlet of pump 3 to the inlet of three-way valve 12 has ambient pressure (approximately 1 bar). This portion or volume is the dead zone volume 22. After switching from the purging step to the degassing step, the air in the dead zone volume 22 is particularly contaminated in the analysis volume or first portion volume 1 where sensor 4 is arranged.

[0065] After the purging step, the degassing container 7 is disconnected from the apparatus 10 by closing the third valve 11. Then, by switching the three-way valve 12, neither the outlet of pump 3 nor the first volume (more precisely, the first partial volume 1) is connected to the outlet 21, thereby achieving pressure equalization. Specifically, the three-way valve 12 is switched so that the outlet of pump 3 is connected only to the first volume (more precisely, the first partial volume 1). As a result of pressure equalization, the pressure setting is determined by the ratio of the volumes of the first volumes 1, 2 and the second volume 6 to the dead zone volume 22. Because the second volume or the gas tank 6 is very large, the pressure increase in the first volumes 1, 2, and especially the first partial volume 1 in which the gas is to be analyzed is much less than the pressure without the gas tank 6. As a result, the contamination caused by the dead zone volume 22 is also relatively small. For example, with an analysis volume 1 of 500 µl, an expansion volume 2 of 10 ml, and a gas tank 6 of 750 ml, a pressure of 0.6 mbar can be set in the first volumes 1, 2, and the second volume 6. The pressure in the sealed degassing container 7 is maintained at 0.1 mbar.

[0066] After the pressure is evenly distributed in volumes 1, 2, and 6 of the device 10, the second volume or gas tank 6 is disconnected by closing the first valve 6.

[0067] In addition, the degassing container 7 is advantageously filled with the liquid to be degassed (e.g., oil 5).

[0068] The disconnection of gas tank 6 and the filling of degassing container 7 can be performed in any desired order. These two steps can also be performed simultaneously.

[0069] After the second volume or gas tank 6 is disconnected and the degassing container 7 is filled, the gas in the liquid 5 to be degassed is degassed or pumped into the device 10 during the degassing step. For this purpose, the third valve 11 is opened and the second valve 14 is closed. The three-way valve 12 also connects the outlet of the pump 3 only to the first volume (more precisely, the first partial volume 1), and the auxiliary valve 13 is opened and also connects the first partial volume 1 to the expansion volume or the second partial volume 2, while the first valve 15 is also closed. The pump 3 is then activated, which pumps gas from the degassing container 7 into the first volumes 1 and 2.

[0070] An optional compression step can be performed between the degassing step and the subsequent measurement step to compress the gas in the first partial volume or analysis volume 1. For this compression step, the first valve 15 remains closed, and the three-way valve 12 connects the outlet of pump 3 only to the first partial volume 1. The third valve 11 and the auxiliary valve 13 are closed, while the second valve 14 is open. Pump 3 then pumps gas from the second partial volume or expansion volume 2 into the first partial volume 1, resulting in compression of the gas in the first partial volume or analysis volume 1. This improves the analysis of the gas by sensor 4 in analysis volume 1. The more the gas in analysis volume 1 is compressed, the higher the concentration of certain particles to be analyzed in the gas, which benefits the analytical capability of sensor 4.

[0071] It should be noted that the present invention allows the evacuation, degassing, and compression steps to be performed using the same pump 3. In particular, no additional pump is required to pump air out of the dead zone volume 22 at the outlet of pump 3.

[0072] After the degassing step or optionally after the compression step, a measurement step is performed in which the gas in the first volume or analysis volume 1 is analyzed with the assistance of sensor 4.

[0073] The degassing process or degassing step, as well as the activation of valves 11-15 and pump 3, are preferably executed automatically or by a suitable control unit (see [link]). Figure 2 The control unit 19 shown is executed in a computer-aided manner.

[0074] Figure 2 A test system 30 and a high-voltage device 40 according to the invention are schematically depicted. The test system 30 is designed to inspect the insulation 41 of the high-voltage device 40. The test system 30 includes a degassing device 10 according to the invention, which is as described above and Figure 1The diagram is schematically depicted. Furthermore, the test system 30 includes an evaluation unit 20 to plot inspection results based on venting, degassing, and optional compression, and the device 10 uses its control unit 19 to perform subsequent gas analysis. The device 10 analyzes the gas from the insulating element 41 using the mass of the insulating element 41, thereby measuring the operational readiness of the high-voltage equipment 40 itself, which can be determined by analyzing the gas.

Claims

1. An apparatus (10) for degassing a degassing container (7), the degassing container (7) being capable of being filled with a liquid to be degassed. It has a pump (3), which is designed to pump gas and is connected at the discharge end to the outlet (21) via a valve device (12) and to the first volume (1, 2) via the valve device (12). in, The first volume (1, 2) is connected to the second volume (6) via the first valve (15). The pump (3) is connected to the first volume (1, 2) at its suction end via a second valve (14), and can also be connected to the degassing container (7) to be degassed. It has a control unit (19) for activating the pump (3), the valve device (12), the first valve (15), and the second valve (14). The device (10) is designed to switch the valve device (12) via the control unit (19) so that the valve device (12) connects the pump (3) to the outlet (21) at the discharge end, opens the first valve (15) and the second valve (14), and then empties the degassing container (7), the first volume (1, 2) and the second volume (6) via the pump (3).

2. The apparatus according to claim 1, Its features The second volume (6) is at least ten times larger than the first volume (1, 2).

3. The apparatus according to claim 1, Its features The device (10) is designed to switch the valve device (12) via the control unit (19) such that the valve device (12) connects the pump (3) to the first volume (1, 2) only at the discharge end, and opens the first valve (15) and the second valve (14) such that pressure equalization is subsequently performed in the total volume formed by the first volume (1, 2) and the second volume (6) and the dead zone volume (22).

4. The apparatus according to claim 1, Its features The device (10) is designed to switch the valve device (12) via the control unit (19) such that the valve device (12) connects the pump (3) to the first volume (1, 2) only at the discharge end, and closes the first valve (15) and the second valve (14), and then pumps gas from the degassing container (7) into the first volume (1, 2) via the pump (3).

5. The apparatus according to claim 1, Its features The device (10) includes a third valve (11), at the suction end, the pump (3) is connected to the degassing container (7) to be degassed via the third valve (11).

6. The apparatus according to claim 5, Its features The device (10) is designed to switch the valve device (12) via the control unit (19) such that the valve device (12) connects the pump (3) to the outlet (21) at the discharge end, opens the first valve (15), the second valve (14) and the third valve (11), and then empties the degassing container (7), the first volume (1, 2) and the second volume (6) via the pump (3).

7. The apparatus according to claim 5, Its features The device (10) is designed to switch the valve device (12) via the control unit (19) such that the valve device (12) connects the pump (3) to the first volume (1, 2) at the discharge end, opens the first valve (15) and the second valve (14) and closes the third valve (11), so that pressure equalization is subsequently performed in the total volume formed by the first volume (1, 2) and the second volume (6) and the dead zone volume (22).

8. The apparatus according to claim 5, Its features The device (10) is designed to switch the valve device (12) via the control unit (19) such that the valve device (12) connects the pump (3) to the first volume (1, 2) only at the discharge end, closes the first valve (15) and the second valve (14) and opens the third valve (11), and then pumps gas from the degassing container (7) into the first volume (1, 2) via the pump (3).

9. The apparatus according to claim 1, Its features The device (10) includes a sensor (4) arranged in the first volume, and The sensor (4) is designed to analyze the gas in the first volume.

10. The apparatus according to claim 5, Its features The first volume includes a first portion volume and a second portion volume connected via an additional valve (13) of the device (10). The device (10) is designed to switch the valve device (12) via the control unit (19) such that the valve device (12) connects the pump (3) to the first volume (1, 2) only at the discharge end, closes the first valve (15), the third valve (11) and the additional valve (13), opens the second valve (14), and then pumps gas from the second volume into the first volume via the pump (3).

11. The apparatus according to claim 1, Its features The device (10) is designed to degas the insulating fluid of the high-voltage equipment (40).

12. A testing system, in, The test system (30) includes an evaluation unit (20) and a device (10) according to any one of claims 1 to 11 for analyzing the gas in or from the degassing container (7).

13. A method for degassing a degassing container (7) using the apparatus (10) according to any one of claims 1-11, the method comprising the steps of: Connect the first volume (1, 2) to a second volume (6) provided separately from the first volume (1, 2). The degassing container (7), the first volume (1, 2), and the second volume (6) are emptied. Disconnect the degassing container (7) from the first volume (1, 2) and the second volume (6). Pressure equalization is performed in the total volume formed by the first volume (1, 2), the second volume (6), and the dead zone volume (22). The second volume (6) is disconnected from the first volume (1, 2). The degassing container (7) is filled with the liquid to be degassed, and The degassing container (7) is degassed into the first volume (1, 2).

14. The method according to claim 13, Its features The first volume includes a first portion volume and a second portion volume, and After degassing in the degassing container (7), the following steps are performed: Disconnect the second part of the volume from the first part of the volume, and Gas is pumped from the second volume into the first volume.

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