Work machine with an energy generation or energy conversion system having a mechanical, in particular electromechanical unit, in particular an electrical transformer

Abstract

The invention relates to a work machine (10) with an energy generation or energy conversion system (14) comprising a mechanical, in particular electromechanical, unit, wherein an oil circuit (11) is assigned to the mechanical unit, wherein at least a portion of the oil conveyed in the oil circuit (11) is passed through a treatment device (22), wherein the treatment device (22) comprises a treatment region (22.1) in which an anion exchanger (22.2) is held, and wherein the anion exchanger (22.2) comprises a complex-bound reducing agent for removing at least a portion of the oxygen from the oil conveyed through the treatment region (22.1). In this way, oxidation of the oil can be avoided and thus its functionality can be maintained.

Description

The invention relates to a working machine with an energy generation or energy conversion system which has a mechanical, in particular electromechanical unit.Such a working machine can be, in particular, an electrical transformer within the scope of the invention. A transformer is a component of electrical technology. It usually consists of two or more coils (windings) which are usually wound from insulated copper wire and are located on a common magnetic core. A transformer converts an AC input voltage applied to one of the coils into an AC output voltage that can be tapped at the other coil. Transformers are often used for voltage conversion in energy supply systems. Furthermore, they are required in signal transmission and protection isolation. Transformers frequently use transformer oil, which is then also referred to as insulating oil. This is a highly refined mineral oil or a low viscosity silicone oil which is stable at high temperatures. The transformer oil serves for the isolation or for cooling of the transformer. Insulating oil is also used in other working machines, for example in high-voltage technology, capacitors and switches, it frequently also being used for the purpose of extinguishing sparks. Due to aging, the oil must be subjected to a regular test and changed as needed to ensure functionality. This results in a high maintenance effort and downtime in which the work machine cannot be used must be taken into account.It is the object of the invention to provide a working machine of the type mentioned at the beginning, with which low-maintenance operation can be realized.This object of the invention is achieved with the features of claim 1. Accordingly, a working machine with an energy generation or energy conversion system is proposed, which has a mechanical, in particular electromechanical unit, wherein an oil circuit is assigned to the mechanical unit, wherein at least a portion of the oil circuit is conducted through a treatment device, wherein the treatment device has a treatment region in which an anion exchanger is held and wherein the anion exchanger has, bound in a complex manner, a reducing agent for removing at least part of the oxygen from the oil conducted through the treatment region.The oil used in a working machine according to the invention absorbs a large amount of gas, in particular oxygen from the air, under normal process conditions. The oxygen leads to oxidation of the oil, which leads to a deterioration of the properties, for example the dielectric properties. In a transformer system, the result is a decrease in electrical strength. In addition, the oxidation of the oils used also promotes their foaming. In order to counteract these negative processes, according to the invention a treatment device is proposed in the treatment region of which an anion exchanger is held, preferably an anion exchanger resin in granulate form. According to the invention, the anion exchanger is provided with a complex-bound reducing agent. When the oil is passed through the treatment device, it is passed by the anion exchanger in the treatment region. The reducing agent is an oxygen-consuming chemical. When the oil is contacted with the reducing agent, a portion of the oxygen dissolved in the oil is removed by reaction with the reducing agent. As a result, the oxygen present in the oil can be at least partially removed.Thus, the use properties of the oil can be improved or restored without the oil having to be completely replaced. As a result, downtime can be reduced or the functionality of the working machine can be improved. Advantageously, the oxidized form of the reducing agent remains on the ion exchanger and thus does not enter the oil.Within the scope of the invention, it may be the case that the oil circuit provides a circulation operation, wherein the oil to be treated is at least partially repeatedly conducted through the treatment region in order to achieve a continuous oxygen consumption.In this case, it can be provided that the entire fill quantity in the oil circuit is conducted through the treatment region. However, it is also conceivable for a bypass of the circuit to be provided. Then, only a portion of the oil is bypassed through the treatment area. In this way, in particular, a continuous deoxidizing of the oil can be carried out, wherein oxygen is removed from the oil proportionally with the reducing agent. By the circulation operation, the oil is repeatedly passed through the ion exchanger. As a result, the oxygen is completely or almost completely removed from the oil even at comparatively slow reaction speeds between the reducing agent and the oxygen.It is preferably such that the treatment space is arranged downstream of the mechanical unit in the flow direction. This is advantageous in particular when heat is introduced into the oil by means of the mechanical unit. Here, the finding is utilized that the reaction rate of the reducing agent is higher in the warm oil than in the cold oil. In addition, the viscosity is lower, which facilitates the passage of the oil through the treatment space.However, if the temperature of the oil downstream of the mechanical unit is so high that damage to the anion exchanger is to be feared, the treatment region is preferably arranged downstream of a heat exchanger in the flow direction, which serves to cool the oil.According to a preferred variant of the invention, it can be provided that the reducing agent is formed at least partially, preferably for the most part, in particular completely, of sulfite ions. Sulfite ions have an oxygen-consuming effect. Upon contact with the oil, they react with the oxygen dissolved in the oil, thereby reducing the oxygen and oxidizing the sulfite ion to the sulfate ion. Advantageously, the sulfate ion has no lower affinity for the anion exchanger than the reduced form of the sulfite, so that it remains on the anion exchanger. Preferably, it can be provided that hydroxide ions OH - are replaced proportionally in the anion exchanger by ions of the reducing agent, preferably by sulfite ions. This can counteract, for example, an increase in the oil.If it is provided that a filter, in particular a depth filter, is integrated into the oil circuit downstream of the treatment region in the flow direction, then any substances emerging from the anion exchanger can be filtered out.As mentioned above, the treatment region may be arranged in a bypass to a main flow region. Accordingly, the bypass forms a bypass region in which the treatment region is accommodated. Thus, the bypass flow region is branched off from a main flow region and runs parallel thereto. It can be advantageous in this case that the oil is conveyed through the bypass flow region by means of a bypass flow pump arranged in the bypass flow region in order to ensure the treatment of the oil.It has been found that good removal of the oxygen from the oil is possible if it is provided that the volume flow through the treatment region is in the range between 10 and 30 bed volumes (BV / h), wherein the bed volume is the volume occupied by the anion exchanger in the treatment region.The object of the invention is also achieved by a treatment device for at least partially removing oxygen from an oil for a mechanical, in particular electromechanical unit, wherein a treatment device is provided, wherein the treatment device has a treatment region in which an anion exchanger is held and wherein the anion exchanger has, bound complexly, a reducing agent for removing at least part of the oxygen from the oil guided through the treatment region. Reference is made to the advantages described above. The treatment device can be used in the oil circuit of a working machine as described. In addition, it is also possible to use the treatment device for filling a working machine with oil, wherein the oil is then guided over the treatment device. It is furthermore conceivable that the treatment device is also used at a refeed connection of an oil circuit, wherein the oil supplied via the refeed connection is then treated by means of the treatment device in order to remove at least partially oxygen present therein.It can particularly preferably be provided that the residual water content of the anion exchanger held in the treatment region is ≤3%, preferably ≤1%, particularly preferably ≤0.5%. In this way, water is effectively prevented from impairing the functionality of the anion exchanger.This places particular requirements on the production of the anion exchanger. Since the loading process of the anion exchanger takes place in an aqueous medium. In the context of the invention, it can now be provided that after the conversion of the anion exchanger in aqueous medium, a further process step is integrated into the production, wherein the anion exchanger is rinsed with an organic liquid, which is preferably miscible with water and further preferably easily evaporates. For example, alcohol, especially preferably isopropanol or ethanol, can be used. It is also conceivable that a mixture of different alcohols is used. When the anion exchanger is rinsed with the organic liquid, it absorbs the water from the anion exchanger. This step can preferably be monitored until the desired maximum residual water content is established. It can subsequently be provided that the anion exchanger is dried in the treatment space by means of an inert gas stream, for example by means of nitrogen or argon, in order to drive off the volatile organic liquid. Surprisingly, it has been found that after this drying process, the inorganic reducing agent with which the resin has been converted can be used well according to the invention for oxygen removal in oils.The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing. The drawing shows a working machine 10 in schematic representation. the working machine 10 has a power generation or conversion installation 14, in the present case an electrical transformer. Electrical energy can be generated or converted by means of the transformer. The transformer is assigned an oil circuit 11 through which oil is conducted. This is the insulating oil of the transformer.If necessary, it can be provided that a secondary feed line 12 is assigned to the oil circuit 11. Via this afterfeed line 12, missing oil can be filled into the oil circuit 11.As the drawing illustrates, it can also be the case that at least one heat exchanger 17 is integrated into the oil circuit 11. The heat dissipated from the transformer with the oil can be exchanged into the environment via the heat exchanger.In order to convey the oil in the oil circuit 11, a pump 15 is used. The pump 15 can be integrated either in the feed line 16 coming from the transformer or in the return line 13 leading to the transformer.As the illustration shows, the cooling circuit forms a main flow region 30, through which the oil is circulated. A bypass flow region 40 branches off from the main flow region 30, wherein the bypass flow region 40 runs parallel to the main flow region 30. It can be the case that the bypass flow region 40 is integrated into the region of the return 16, as FIG. 1 shows. However, it is also conceivable for the bypass flow region 40 to be integrated into the forward flow 13.As the illustration shows, two shut-off valves 20, 24 are assigned to the bypass flow region 40. By means of these, the bypass flow region 40 can be separated from the main flow region 30.The illustration furthermore shows that a treatment device 22 is integrated into the bypass flow region 40. The treatment device 22 is preferably arranged in the region between the two shut-off valves 20, 24. When the shut-off valves 20, 24 are closed, the treatment device 22 can be removed from the bypass flow region 40 for maintenance purposes without the main flow region 30 being impaired in the process.For delivering the oil through the bypass flow region 40, a bypass flow pump 21 is provided, which operates in the bypass flow region 40.The treatment device 22 has a treatment region 22.1, through which the oil guided in the bypass flow region 40 can flow. In this treatment region 22.1, an anion exchanger 22.2, in particular an anion exchange resin, is held.The anion exchanger 22.2 has, bound complex, a reducing agent for removing at least part of the oxygen from the oil passed through the treatment region 22.1.The reducing agent may be sulfite ions held complexly bound on the resin of the anion exchanger. As oil passes through the treatment area 22.1, sulfite ion reacts with the oxygen of the oil to form sulfate.In order to prevent materials, in particular resin particles, from being washed out of the treatment region 22.1, it can be provided that a filter 23, in particular a depth filter, is arranged downstream of the treatment device 22 in the flow direction.

Claims

Working machine (10) having an energy generation or energy conversion system (14) which has a mechanical, in particular electromechanical unit, wherein an oil circuit (11) is assigned to the mechanical unit, wherein at least a portion of the oil guided in the oil circuit (11) is guided through a treatment device (22), wherein the treatment device (22) has a treatment region (22.1), in which an anion exchanger (22.2) is held, and wherein the anion exchanger (22.2) has, bound complexly, a reducing agent for removing at least part of the oxygen from the oil guided through the treatment region (22.1).Working machine according to Claim 1, characterized in that the reducing agent is formed at least partially, preferably predominantly, in particular completely, by sulfite ions.Working machine according to claim 1 or 2, characterised in that in the case of the anion exchanger (22.2), at least partially OH -- ions are replaced by ions of the reducing agent, preferably by sulphite ions.Working machine according to one of Claims 1 to 3, characterized in that the treatment region (22.1) is arranged downstream of the mechanical unit in the direction of flow in the return of the oil circuit (11).Working machine according to one of Claims 1 to 4, characterized in that, downstream of the treatment region (22.1) in the direction of flow, a filter, (23) in particular a depth filter, is integrated into the oil circuit.Working machine according to one of Claims 1 to 5, characterized in that the treatment region (22.1) has a bypass flow region (40) which is branched off from a main flow region (30) and runs parallel thereto, wherein the treatment region (22.1) is arranged in the bypass flow region (40) and wherein preferably a bypass flow pump (21) conveys the oil through the bypass flow region (40).Working machine according to one of Claims 1 to 6, characterized in that a heat exchanger (17) is arranged in the oil circuit (11), preferably downstream of the mechanical unit in the direction of flow.Working machine according to one of Claims 1 to 7, characterized in that the mechanical unit (14) is an electrical transformer.Working machine according to one of Claims 1 to 8, characterized in that the volume flow through the treatment region (22.1) is in the range between 10 and 30 bed volumes (BV), wherein the bed volume is the volume which the anion exchanger (22.2) assumes in the treatment region (22.1).Treatment device for at least partially removing oxygen from an oil for a mechanical, in particular electromechanical unit (14), wherein a treatment device (22) is provided, wherein the treatment device (22) has a treatment region (22.1) in which an anion exchanger (22.2) is held, and wherein the anion exchanger (22.2) has, bound in a complex manner, a reducing agent for removing at least part of the oxygen from the oil guided through the treatment region (22.1).Treatment device according to claim 10, characterised in that the reducing agent is formed at least partially, preferably for the most part, in particular completely, by sulphite ions, wherein it is preferably provided that in the anion exchanger (22.2) at least partially OH -- ions are replaced by ions of the reducing agent, preferably by sulphite ions.Treatment device according to claim 10 or 11, characterised in that the residual water content of the anion exchanger (22.2) held in the treatment region (22.1) is ≤5%, preferably ≤3%, particularly preferably ≤1%.Treatment device according to one of Claims 10 to 12, characterized in that the anion exchanger (22.2) is a strongly basic anion exchange resin.Working machine according to one of Claims 1-9 having a treatment device according to one of Claims 10-13.

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