Device with collecting tank

Abstract

The invention relates to a device (1) and a method, the device (1) comprising a collection tank (2) having a feed (3) for a mixture of barrier oil and a refrigerant, the collection tank (2) further comprising a discharge (10) for the barrier oil, the collection tank (2) further comprising an additional tank (6), the additional tank (6) is designed to collect the refrigerant and is fluidically connected to the collecting tank (2).

Description

Technical Field

[0001] The present invention relates to an apparatus including a collection tank having a conveying section for a mixture of barrier oil and refrigerant, and further including an outlet section for the barrier oil.

[0002] Furthermore, the present invention relates to a method for collecting barrier oil and refrigerant, wherein in one step a mixture consisting of barrier oil and refrigerant is guided into a collection tank. Background Technology

[0003] A turbo compressor, which can also be configured as a heat pump, is used to compress process gases in the process technology. In the case of a heat pump, the process gas is also called a refrigerant. The turbo compressor has a rotor, which is supported by bearings outside a housing surrounding the rotor. Because there is relative movement between the rotor and the housing during turbo compressor operation, a clearance is maintained at the location where the rotor shaft extends outward from the inside of the housing. This clearance is compensated by a shaft seal to suppress leakage of process gas from the inside of the turbo compressor to the outside, or at least to keep the leakage acceptablely small. If the process gas is flammable, toxic, and / or environmentally hazardous, then the requirements for the shaft seal in terms of its sealing performance are high. It is known that oil-lubricated sliding bearings, especially oil-lubricated tilting pad bearings, are used for the bearings. The design of this sliding bearing is coordinated with the rotor's operating speed and rotor dynamics, wherein the shaft seal and the bearing are directly adjacent to each other on the shaft.

[0004] High demands are placed on shaft seals in cyclic processes, such as refrigeration circuits. Leakage of process gases from the turbo compressor must be minimized. If the shaft seal is configured as a liquid seal, for example, using a barrier oil for barrier purposes, then the barrier oil must be selected to be chemically compatible with the refrigerant. Traditionally, barrier oils are also used as lubricants for bearings, resulting in turbo compressors being supplied with a combined lubricating oil / barrier oil system, where the barrier oil must also be suitable for lubricating and cooling the bearings, thus requiring the barrier oil to meet various requirements. For example, mineral oil may not be suitable as a barrier oil for lubricating bearings and barrier shaft seals because it may be incompatible with the refrigerant used in the cooling process. A remedy is to develop special synthetic oils; however, these synthetic oils are highly hygroscopic and therefore cannot be exposed to the humidity of the external atmosphere.

[0005] Therefore, in the oil-lubricated slip ring seals of refrigerant compressors, the barrier oil can absorb refrigerant during operation. The refrigerant must be drawn back into the refrigerant circuit in a gaseous state through an extraction process. The problem in this case is that the extraction process must be carried out under near-atmospheric conditions because the sealing system is open to the atmosphere on one side.

[0006] The atmospheric side is open in conventional seals and is exposed to the environment. Therefore, there is always an emission in such seals. Thus, efforts are made to keep this leakage as small as possible. Summary of the Invention

[0007] In this context, the object of the present invention is to provide an apparatus in which refrigerant is prevented from being released.

[0008] This objective is achieved by an apparatus comprising a collection tank having a conveying section for a mixture of barrier oil and refrigerant, a drain section for the barrier oil, and an auxiliary tank configured to collect the refrigerant and connected to the collection tank in a flow technology.

[0009] Furthermore, the objective is also achieved by a method for collecting barrier oil and refrigerant, the method comprising the following steps:

[0010] - The mixture consisting of barrier oil and refrigerant is transported to a collection tank;

[0011] - The refrigerant flowing out of the barrier oil will be collected in an auxiliary tank.

[0012] The present invention achieves approximate prevention of refrigerant discharge by using an auxiliary tank configured to collect the refrigerant and having a variable volume.

[0013] A fundamental concept of this invention is that the auxiliary tank has a bladder that collects refrigerant and whose volume is variable. Therefore, refrigerant exchange is possible between the auxiliary tank and the collection tank during operation.

[0014] The refrigerant canister, which could also be referred to as the atmospheric refrigerant canister, should now cause a leak in the seal and separation from atmospheric air, a separation that can only establish a minimum pressure difference. Therefore, it is no longer possible to exchange the refrigerant into the environment.

[0015] A bladder made of elastic material is installed in an auxiliary tank and encloses the filled sealing oil. The bladder contracts when returned to the sealing oil circuit from the tank, the bladder matching the volume of the sealing oil. The cavity between the inner wall of the tank and the bladder is then filled with air instead of refrigerant vapor, allowing the cavity to breathe towards the atmosphere.

[0016] The advantage is that it prevents refrigerant from being released into the environment.

[0017] Preferred improvements are described in the dependent claims.

[0018] The features, characteristics, and advantages of the present invention described above, and the ways and methods of achieving such features, characteristics, and advantages, become clearer and easier to understand in conjunction with the following description of the embodiments, which are illustrated in detail with reference to the accompanying drawings.

[0019] Here, the same components or components with the same function are given the same reference numerals. Attached Figure Description

[0020] Embodiments of the invention are described below with reference to the accompanying drawings. The drawings are not necessarily to scale; rather, they are given in a schematic and / or slightly modified manner to aid in explanation. For supplementation to the teachings readily apparent from the drawings, refer to the relevant prior art.

[0021] The attached diagram shows:

[0022] Figure 1 A schematic diagram of one embodiment of the device according to the present invention is shown. Detailed Implementation

[0023] Figure 1 A schematic diagram illustrating one embodiment of the present invention is shown.

[0024] Figure 1 The apparatus 1 includes a collection tank 2. The collection tank 2 is configured to be filled with a mixture of barrier oil and refrigerant. The mixture of barrier oil and refrigerant originates, for example, from a turbo compressor or heat pump, in which the barrier oil is used in the shaft seal, and wherein the barrier oil mixes with the refrigerant in small amounts during operation. The refrigerant is used as a process gas in the turbo compressor or heat pump.

[0025] Accordingly, the mixture of barrier oil and refrigerant generated in the turbo compressor or heat pump is delivered to the collection tank 2 via the conveying section 3. The mixture of barrier oil and refrigerant accumulates in the collection tank 2, wherein the refrigerant is released from the barrier oil, i.e., separated, and accumulates on top of the barrier oil over time.

[0026] exist Figure 1 The first fill height 4 with barrier oil is shown by a dashed line. Accordingly, the barrier oil can accumulate up to the line, where the space above the dashed line is then filled with refrigerant. Two additional dashed lines above the dashed line 4 exemplarily depict additional fill heights with barrier oil.

[0027] The refrigerant reaches the auxiliary tank 6 via pipe 5. Pipe 5 establishes a flow-technical connection between the collection tank 2 and the auxiliary tank 6. Here, pipe 5 is located in a geographically elevated position.

[0028] The auxiliary tank 6 comprises a shell 7, within which a bladder 8 is located, ultimately filled with refrigerant. The volume of the bladder 8 is variable to allow refrigerant to accumulate gradually during operation. Therefore, the bladder 8 is constructed of an elastic material. The upper half of the diagram of the auxiliary tank 6 shows the state of the bladder 8, in which it is relatively well-filled, while the lower half of the diagram shows a smaller degree of filling, which can be seen from the smaller volume of the bladder 8.

[0029] Therefore, the operation of capsule 8 is similar to that of a balloon whose volume can also change. Here, the volume of capsule 8 also changes according to operating conditions, thus the amount of refrigerant temporarily stored is variable.

[0030] This device 1 prevents refrigerant from leaving the turbine compressor process or heat pump process and entering the atmosphere.

[0031] An air vent is provided between the bladder 8 and the shell 7.

[0032] A valve 9 is installed in pipeline 5, which is normally open when filling bladder 8. During operation, a certain amount of barrier oil is discharged via outlet 10. The discharge of the barrier oil creates a negative pressure above filling height 4. This causes the space above the barrier oil in collection tank 2 to be filled with refrigerant from auxiliary tank 6.

[0033] If the refrigerant charge in collection tank 2 and auxiliary tank 6 reaches its upper limit, the refrigerant is drawn off via vent valve 11 located in pipeline 5. In this case, the refrigerant can be delivered again as a process gas to the turbo compressor or heat pump. Valve 9 must remain closed when the refrigerant is drawn off via vent valve 11.

[0034] Therefore, the collecting tank 2 and the auxiliary tank 6 are operated such that the collecting tank 2 is filled with a mixture of barrier oil and refrigerant, the refrigerant is separated from the barrier oil and collected in the auxiliary tank 6, wherein after the barrier oil separated from the refrigerant is drawn out, the collecting tank 2 is filled with refrigerant from the auxiliary tank 6.

[0035] Because the barrier oil drawn from collection tank 2 may still contain refrigerant, the barrier oil separates from the refrigerant during the downstream process, which will not be described in detail here.

[0036] Although the details of the invention have been described and illustrated with reference to preferred embodiments, the invention is not limited to the disclosed examples and other variations can be derived by those skilled in the art without departing from the scope of protection of the invention.

Claims

1. An apparatus (1), said apparatus (1) comprising: Collection tank (2), which has a conveying section (3) for a mixture of barrier oil and refrigerant. The collection tank (2) also includes an outlet (10) for blocking oil. The collection tank (2) also has an auxiliary tank (6) which is configured to collect refrigerant and is connected to the collection tank (2) in a flow technology.

2. The apparatus (1) according to claim 1. The additional can (6) therein has a bladder (8) made of elastic material.

3. The apparatus (1) according to claim 2. The volume of the sac (8) is variable.

4. The apparatus (1) according to claim 2 or 3. A shell (7) is provided around the sac (8). Air is provided between the housing (7) and the bladder (8), and the air is connected to the atmosphere via a valve.

5. The apparatus (1) according to any one of the preceding claims. A valve (9) is provided between the collection tank (2) and the auxiliary tank (6).

6. The apparatus (1) according to any one of the preceding claims. The collection tank (2) therein has an exhaust valve (11) that forms a flow-technical connection between the refrigerant in the collection tank (2) and the auxiliary device.

7. A method for collecting barrier oil and refrigerant, the method comprising the following steps: - The mixture consisting of barrier oil and refrigerant is transported to the collection tank (2); - The refrigerant flowing out of the barrier oil is collected in the auxiliary tank (6).

8. The method according to claim 7, When the barrier oil is removed from the collection tank (2) via the outlet (10), the collection tank (2) is filled with refrigerant from the auxiliary tank (6).

9. The method according to claim 7 or 8, A valve (9) is provided between the auxiliary tank (6) and the collection tank (2).

10. The method according to any one of claims 7 to 9, The flow technology connection is provided between the collection tank (2) and the auxiliary tank (6) by an exhaust valve (11), which establishes a flow technology connection between the refrigerant in the collection tank (2) and the auxiliary device.

11. The method according to any one of claims 7 to 10, The additional canister (6) therein comprises a bladder (8) made of elastic material, wherein the volume of the bladder (8) is variable.

12. The method according to any one of claims 7 to 11, In the method, in the first process step, the mixture consisting of barrier oil and refrigerant is in the collection tank (2), and the refrigerant is separated from the barrier oil and accumulates above the barrier oil, wherein the refrigerant above the barrier oil fills the auxiliary tank (6), wherein in the second process step, the collected barrier oil is taken out via the outlet (10), and the space above the barrier oil in the collection tank (2) is filled by the refrigerant from the auxiliary tank (6).

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