Apparatus, method, and solvent for cleaning turbine components

A cleaning method and a cleaning fluid are provided. The cleaning method includes accessing a plurality of turbine components attached to a turbine assembly, the turbine assembly being a portion of a turbomachine, positioning at least one cleaning vessel over at least one of the turbine components, forming a liquid seal with a sealing bladder, providing a cleaning fluid to the cleaning vessel, and draining the cleaning fluid from the cleaning vessel. The cleaning fluid includes a carrier fluid and a solvent additive for removing fouling material from the turbine component. An alternative cleaning method is also provided.

FIELD OF THE INVENTION

The present invention is directed to an apparatus, a method, and a solvent for cleaning turbine components. More specifically, the present invention is directed to an apparatus, a method, and a solvent for removing fouling material from turbine components.

BACKGROUND OF THE INVENTION

Gas turbines (GT) are often subjected to harsh operating conditions and prolonged operation times, leading to fouling of turbine components. For GT compressor components, fouling may adversely affect the aerodynamic performance of the turbine components by increasing the coefficient of drag (CD) and resulting in reduced performance. Usually during major inspections, which are conducted at predetermined intervals, turbine components such as rotor blades and stator vanes are manually scrubbed and/or cleaned to partially restore the surface finish of the blades and vanes. The scrubbing and/or cleaning of the rotor blades and vanes improves the surface finish, partially restoring GT output and efficiency. However, current methods of cleaning do not fully restore the surface finish to that of a new turbine component.

Manual scrubbing and/or cleaning of the rotor blades is a time-consuming process which results in a less than optimal surface finish of the blade. An alternative to manual scrubbing and/or cleaning of the rotor blades is submerging the turbine components in a cleaning fluid.

Submerging of the rotor blades in a cleaning fluid provides an improved surface finish of the blade, as compared to manual scrubbing. However, current methods and/or cleaning fluids require disassembly and/or transportation of the GT. Disassembly and transportation increase the GT downtime, resulting in lost productivity. Downtime for transportation of the GT can be up to two months.

A cleaning method that does not suffer from one or more of the above drawbacks is desirable in the art.

BRIEF DESCRIPTION OF THE INVENTION

In one exemplary embodiment, a method for cleaning a gas turbine includes accessing a plurality of turbine components attached to a turbine assembly, the turbine assembly being a portion of a turbomachine, positioning at least one cleaning vessel over at least one of the turbine components, forming a liquid seal with a sealing bladder, providing a cleaning fluid to the cleaning vessel, and draining the cleaning fluid from the cleaning vessel. The cleaning fluid comprises a carrier fluid and a solvent additive for removing fouling material from the turbine component.

In another exemplary embodiment, a method for cleaning a gas turbine includes accessing a plurality of turbine components attached to a turbine assembly, the turbine assembly being a portion of a turbomachine, providing a cleaning fluid in a cleaning vessel, rotating the plurality of turbine components to at least partially immerse the turbine components in the cleaning fluid in the cleaning vessel, and separating the plurality of turbine components from the cleaning fluid in the cleaning vessel. The cleaning fluid comprises a carrier fluid and a solvent additive for removing a fouling material from the turbine components.

In another exemplary embodiment, a cleaning fluid for cleaning a gas turbine includes a solvent additive, and a carrier fluid. The solvent additive is capable of removing fouling material from a turbine component immersed in the cleaning fluid.

DETAILED DESCRIPTION OF THE INVENTION

Provided are a cleaning fluid and methods for cleaning a gas turbine. Embodiments of the present disclosure, in comparison to methods and cleaning fluids not using one or more of the features disclosed herein, increase cleaning efficiency, decrease turbine downtime, decrease turbine transportation, decrease labor for polishing, decrease cost of cleaning fluid, decrease cleaning time, increase cleaning effectiveness, or a combination thereof.

Referring toFIGS. 1-2, a method for cleaning a gas turbine is provided. In one embodiment, the method is performed in-situ. For purposes of this application, in-situ means at the operational site or venue of the turbine, such as during a planned inspection. In another embodiment, the method for cleaning the gas turbine includes accessing (step110) a plurality of turbine components230attached to a turbine assembly210, the turbine assembly210being a portion of a turbomachine201. For example, accessing (step110) the plurality of turbine components230may include removing a rotor upper casing to expose a portion of the turbine assembly210. The plurality of turbine components230includes any suitable turbine component, such as, but not limited to, a compressor blade232, a rotor blade, a stator vane, or a combination thereof. In one embodiment, the plurality of turbine components230include platform sections affixed to compressor discs233which are attached to a turbine shaft or sub-shaft211of the turbine assembly210. Exemplary turbine series include, but are not limited to, turbine series 6FA, 7FA, and 9FA produced by General Electric Company, and the turbine assemblies210removed from such series.

As shown inFIGS. 1-3, at least one cleaning vessel220including a sealing bladder413is then positioned (step120) over at least one of the turbine components230. The sealing bladder413forms (step130) a liquid seal between the turbine component230and the cleaning vessel220. Positioning (step120) more than one cleaning vessel220over more than one of the turbine components230permits simultaneous cleaning of the turbine components230. In one embodiment, prior to positioning the cleaning vessel220(step120), the turbine components230are optionally sprayed with a fluid to remove loose debris. Next, a cleaning fluid221is provided to the cleaning vessel220(step140) to immerse the turbine component230and remove a fouling material from the turbine component230. The turbine components230are immersed in the cleaning fluid221for a predetermined time, and/or until the turbine components230include a predetermined finish, and then the cleaning fluid221is drained (step150) from the cleaning vessel220. In another embodiment, the cleaning fluid221within the cleaning vessel220is agitated to increase a rate of removal of the fouling material from the turbine component230.

The cleaning fluid221includes a carrier fluid and a solvent additive. The carrier fluid includes any suitable solvent for carrying the solvent additive, such as, but not limited to, a distillate. Suitable distillates include, but are not limited to, petrochemical distillates such as naphtha, heavy aromatic naphtha, kerosene, diesel, or a combination thereof. The cleaning fluid221includes any suitable amount of the solvent additive, such as, but not limited to, up to about 99%, between about 1% and about 50%, between about 1% and about 30%, between about 10% and about 30%, between about 1% and about 20%, up to about 15%, between about 10% and about 20%, between about 5% and about 10%, about 10%, or any combination, sub-combination, range, or sub-range thereof.

The solvent additive includes any suitable solvent additive capable of removing the fouling material from the turbine component230. In one embodiment, the solvent additive includes a calcium long chain alkyl phenate sulphide. In another embodiment, the calcium long chain alkyl phenate sulphide includes, by weight percent, between about 8.7% and about 9.7% calcium, between about 8.9% and about 9.5% calcium, between about 9.1% and about 9.3% calcium, about 9.2% calcium, or any combination, sub-combination, range, or sub-range thereof. In a further embodiment, the calcium long chain alkyl phenate sulphide includes, by weight percent, between about 2.75% and about 3.75% sulfur, between about 2.95% and about 3.55% sulfur, between about 3.15% and about 3.35% sulfur, about 3.25% sulfur, or any combination, sub-combination, range, or sub-range thereof. For example, one suitable composition of the calcium long chain alkyl phenate sulphide includes, by weight percent, between about 8.7% and about 9.7% calcium, and between about 2.75% and about 3.75% sulfur, with a total base number of between about 225 and about 275 mg KOH/g.

In one embodiment, the solvent additive includes a mix of calcium alkyl phenol sulphide and polyolefin phosphorosulphide. In another embodiment, the mix of calcium alkyl phenol sulphide and polyolefin phosphorosulphide includes, by weight percent, between about 1.1% and about 2.1% calcium, between about 1.3% and about 1.9% calcium, between about 1.55% and about 1.65% calcium, or any combination, sub-combination, range, or sub-range thereof. In a further embodiment, the mix of calcium alkyl phenol sulphide and polyolefin phosphorosulphide includes, by weight percent, between about 0.5% and about 1.5% phosphorous, between about 0.7% and about 1.3% phosphorous, between about 0.9% and about 1.03% phosphorous, or any combination, sub-combination, range, or sub-range thereof. In a further embodiment, the mix of calcium alkyl phenol sulphide and polyolefin phosphorosulphide includes, by weight percent, between about 2.0% and about 3.5% sulphur, between about 2.3% and about 3.3% sulphur, between about 2.4% and about 3.2% sulphur, or any combination, sub-combination, range, or sub-range thereof. For example, one suitable composition of the mix of calcium alkyl phenol sulphide and polyolefin phosphorosulphide includes, but is not limited to, by weight percent, between about 1.1% and about 2.1% calcium, between about 0.5% and about 1.5% phosphorus, and between about 2.3% and about 3.3% sulfur, with a total base number of between about 25 and about 75 mg KOH/g.

In another embodiment, after draining the cleaning fluid221(step150) an aqueous solution is optionally provided (step160) to the cleaning vessel220to remove the cleaning fluid221from the turbine component230. The turbine component230having the predetermined finish is immersed in the aqueous solution for a second predetermined time to remove the cleaning fluid221, then the aqueous solution is drained (step170) from the cleaning vessel220.

In another embodiment, the turbine components230having the predetermined finish are optionally rinsed with water to remove the aqueous solution. The rinsing of the turbine components230with water includes any suitable method for removing the aqueous solution. For example, in one embodiment, prior to removing the cleaning vessel220, the water is provided to the cleaning vessel220then subsequently drained from the cleaning vessel220to remove the aqueous solution. In an alternate embodiment, after draining the aqueous solution (step170), the cleaning vessel220is removed from the turbine component230and the turbine components230are subsequently sprayed with the water (e.g., power washed), to rinse the turbine components230and remove the aqueous solution. Once the fouling material has been removed from the turbine components230, the turbine components230have been rinsed, and the cleaning vessels220have been removed from the turbine components230, a dry corrosion inhibitor is applied over the turbine components230. The dry corrosion inhibitor is applied as any suitable solution, such as, but not limited to, a water based solution which is dried over the turbine components230. The application of the dry corrosion inhibitor includes, but is not limited to, spraying, painting, dipping, rubbing, or a combination thereof. The dry corrosion inhibitor reduces or eliminates formation of corrosion on portions of the turbine components230exposed during removal of the fouling material by the cleaning method.

In an alternate embodiment, once the fouling material has been removed from the turbine components230and the cleaning fluid221is drained (step150) from the cleaning vessel220, the cleaning vessel220is removed from turbine component230without providing an aqueous solution (step160) or rinsing the turbine components230with water. The cleaning fluid221remains on the turbine components230and acts to reduce or eliminate corrosion of the turbine component230, permitting completion of the method without removal of the cleaning fluid221or application of the dry corrosion inhibitor.

The removing of the fouling material from the turbine component230decreases a build-up of fouling material, which may accumulate on the turbine components230during operation of the turbomachine201. The fouling material includes, but is not limited to, a petrochemical film, oxidation, corrosion, foreign objects, such as sand or dust, which may be ingested by the turbomachine201, loose film, other materials that form a film over the turbine component230, or a combination thereof. Decreasing or eliminating the build-up of fouling material on the turbine component230increases an aerodynamic efficiency of the turbine component230, thus increasing the efficiency of the turbomachine201.

Referring toFIG. 3, in one embodiment, the sealing bladder413includes any suitable device for filling a space between the turbine component230and the cleaning vessel and forming the liquid seal. Suitable seals include, but are not limited to, pneumatic seals, circumferential seals, or a combination thereof. In another embodiment, the sealing bladder413is configured to follow a contour of the turbine component230. In a further embodiment, the sealing bladder413is coupled to an air bladder pump411that inflates the sealing bladder413to create the liquid seal.

The liquid seal formed by the sealing bladder413retains a liquid (e.g., the cleaning fluid221, the aqueous solution, water) within the cleaning vessel220to permit immersing of the turbine component230in any orientation. For example, in one embodiment, the plurality of turbine components230that are accessed (step110) by removing the rotor upper casing are extending away from the turbine assembly210in a direction generally opposite that of gravity. The cleaning vessel220positioned (step120) over the turbine component230includes an opening facing opposite the direction of the turbine component230. As liquid is provided to the cleaning vessel220, the sealing bladder413retains the liquid within the cleaning vessel220and permits a filling of the cleaning vessel220with the liquid.

Referring toFIGS. 4-5, in one embodiment, a seal support420is optionally positioned over the opening in the cleaning vessel220to increase retention of the liquid within the cleaning vessel220. The seal support420includes a first side502coupled to a second side504with a securing member430. The securing member430is any suitable member for coupling the first side502to the second side504, such as, but not limited to, a securing pin. The first side502and the second side504form a central opening to permit passage there through of the turbine component230. Upon completion of cleaning the turbine component230, the seal support420is removed, the sealing bladder413is vented, and the cleaning vessel220is removed from the turbine component230.

In one embodiment, the liquid is provided to the cleaning vessel220from at least one liquid supply tank250. The at least one liquid supply tank250is coupled to at least one liquid supply fitting252on the cleaning vessel220through at least one liquid supply line254. In another embodiment, one or more liquid pumps260force the liquid from the at least one liquid supply tank250, through the at least one liquid supply line254, to fill the cleaning vessel220. The one or more liquid pumps260may be integral with a valve manifold270for controlling liquid flow from the at least one liquid supply tank250. A single type of liquid is provided in each of the at least one liquid supply tanks250. For example, in one embodiment, the cleaning fluid221is provided in at least one cleaning fluid supply tank, the aqueous solution is provided in at least one aqueous solution supply tank, and the water is provided in at least one water supply tank.

In one embodiment, the cleaning vessel220includes at least one liquid return fitting282coupled to at least one liquid return tank280through at least one liquid return line284, the liquid return tank280being separate from the liquid supply tank250. In an alternate embodiment, a single tank forms the liquid supply tank250and the liquid return tank280to create a closed loop including the cleaning vessel220. The at least one liquid supply fitting252and the at least one liquid return fitting282permit filling and draining of the cleaning vessel220without venting the sealing bladder413and breaking the liquid seal.

For example, in one embodiment, the cleaning fluid supply tank, the aqueous solution supply tank, and the water supply tank are coupled to the at least one liquid supply fitting252through the liquid supply lines254attached to the liquid pump260integral with the valve manifold270. After pressurizing the sealing bladder413to form the liquid seal, the cleaning vessel220is filled with the cleaning fluid221from the cleaning fluid supply tank. The cleaning fluid221removes the fouling material from the turbine component230within the cleaning vessel220, and is then drained from the cleaning vessel220to the liquid return tank280through the liquid return fitting282. The aqueous solution and the water are subsequently provided to, and drained from the cleaning vessel220in the same manner. In another embodiment, the liquid is provided to the cleaning vessel220concurrently with the draining of the liquid from the cleaning vessel220. The liquid is provided at an increased rate as compared to the draining, to permit filling of the cleaning vessel220. Together, the providing of the liquid and the draining of the liquid agitate the liquid within the cleaning vessel220to provide increased cleaning of the turbine components230.

Referring toFIGS. 6-7, in an alternate embodiment, the method for cleaning the gas turbine includes accessing (step610) the plurality of turbine components230attached to the turbine assembly210, and optionally removing the turbine assembly210from the turbomachine201(step620). After removing the turbine assembly210from the turbomachine201(step620), the turbine assembly210is placed on supports202configured to suspend and/or rotate the turbine assembly210. The cleaning vessel220is then optionally positioned (step630) below the turbine assembly210, and the cleaning fluid221is provided in the cleaning vessel220(step640). In an alternate embodiment, a liner is positioned within the turbomachine201and the cleaning fluid221is provided to the turbomachine201, permitting cleaning of the gas turbine without removing the turbine assembly210. In another embodiment, the cleaning vessel220may be positioned within the turbomachine201to form the liner.

The turbine assembly210is then rotated to rotate the plurality of turbine components230and at least partially immerse the turbine components230in the cleaning fluid221in the cleaning vessel220(step650). The immersion of the plurality of turbine components230in the cleaning fluid221removes the fouling material from the turbine components230to form the predetermined finish. After forming the predetermined finish the cleaning fluid221is optionally drained (step660) from the cleaning vessel220. In another embodiment, the aqueous solution is then optionally provided in a rinsing vessel (step670), and the plurality of turbine components230having the predetermined finish are rotated to at least partially immerse the turbine components230in the aqueous solution and remove the cleaning fluid221(step680). After immersing the turbine component230in the aqueous solution, the aqueous solution is optionally drained from the rinsing vessel.

In one embodiment, the cleaning vessel220forms a rinsing vessel to permit cleaning and rinsing of the turbine components230in the same vessel. In an alternate embodiment, the cleaning vessel220is separate from the rinsing vessel to permit cleaning and rinsing of the turbine components230without draining of the cleaning fluid221or the aqueous solution. For example, after forming the predetermined finish, the cleaning vessel220with the cleaning fluid221may be separated from the turbine assembly210, and the rinsing vessel with the aqueous solution may be positioned relative to the turbine assembly210. The cleaning and rinsing of the turbine components230without draining of the cleaning fluid221or the aqueous solution permits re-use of the cleaning fluid221and/or the aqueous solution.

In one embodiment, subsequent to removing the cleaning fluid221with the aqueous solution, the plurality of turbine components230are rinsed with water to remove the aqueous solution, and then the dry corrosion inhibitor is applied over the turbine components230having the predetermined finish. The plurality of turbine components230may be rinsed by any suitable method. For example, in one embodiment, upon completion of cleaning the turbine components230, the cleaning vessel220is removed from below the turbine assembly210and the turbine components230are power washed. In an alternate embodiment, water is provided to the cleaning vessel220and the turbine components230are rotated through the water to remove the aqueous solution from the turbine components.

In an alternate embodiment, once the fouling material has been removed from the turbine components230, the cleaning fluid221is optionally drained (step660) and/or the turbine components230are separated from the cleaning vessel220without subsequently immersing the turbine components230in the aqueous solution or rinsing the turbine components230with water. The cleaning fluid221remains on the turbine components230and acts to reduce or eliminate corrosion of the turbine component230, permitting completion of the method without removal of the cleaning fluid221or application of the dry corrosion inhibitor.

Referring toFIG. 7, in one embodiment, the cleaning vessel220positioned below the turbine assembly210or within the turbomachine201includes one or more compartments223corresponding to one or more sections of turbine components230on the turbine assembly210. In another embodiment, each compartment223includes the liquid maintained at a predetermined volume level. The predetermined volume level within each compartment223corresponds to a length of the turbine components230in the corresponding section of the turbine assembly210. For example, in one embodiment, at least two of the sections extend away from a centerline of the turbine assembly210at a different length, the corresponding compartments223including differing predetermined volume levels based upon the length of the turbine components230. In another embodiment, the predetermined volume level in each of the compartments223is the same, corresponding to the plurality of turbine components230extending away from the centerline of the turbine assembly210with the same length.

The rotation of the turbine assembly210to immerse the turbine components230in the cleaning fluid221, the aqueous solution, and/or water, may be either continuous or intermittent, and is driven by a rotor drive50. During either continuous or intermittent rotation, the rotation of the turbine assembly210includes a predetermined maximum speed. The predetermined maximum speed is a functional limitation, preventing the liquid from splashing out of the cleaning vessel220. The predetermined maximum speed includes, but is not limited to, between about 1 and about 4 rotations per minute (RPM), between about 2 and about 4 RPM, between about 1 and about 3 RPM, between about 0.5 and about 1.5 RPM, between about 1 and about 2 RPM, between about 2 and about 3 RPM, between about 3 and about 4 RPM, or any suitable combination, sub-combination, range, or sub-range thereof. At or below the predetermined maximum speed, without splashing, the rotation of the turbine assembly210may still remove a portion of the liquid from the cleaning vessel220. Additional liquid is added in some embodiments due to loss of the fluid from the cleaning vessel220.

In one embodiment, a composition of the plurality of turbine components230differs along a length of the turbine assembly210. The composition of the cleaning fluid221may vary between compartments223based upon the composition of the plurality of turbine components230. In another embodiment, the plurality of turbine components230includes the compressor blades232, which do not have a thermal barrier coating, such as is found on the turbine blades. Suitable compositions for the compressor blades232include, but are not limited to, high content steels, such as a precipitation-hardened steel or titanium.