Bearing cylinder for energy recovery unit and preparation deformation control method of bearing cylinder

Abstract

According to the bearing cylinder for the energy recovery unit and the preparation deformation control method of the bearing cylinder, the bearing cylinder is formed by assembling an upper bearing cylinder half body and a lower bearing cylinder half body, each of the upper bearing cylinder half body and the lower bearing cylinder half body comprises a bearing cylinder inner flow channel, a corrosion-resistant layer is additionally arranged in a partial area of the air outlet side of each bearing cylinder inner flow channel, and a chamfer is arranged at the joint of each corrosion-resistant layer and the corresponding bearing cylinder inner flow channel. The chamfer is beneficial to implementation of a welding process and deformation control; a first platform is arranged in the middle of an inner flow channel of the bearing cylinder, an adjustable supporting rod is connected into the first platform, the upper bearing cylinder half body and the lower bearing cylinder half body are combined through process bolts, a whole circle of shroud ring used for increasing fastening tools is arranged on the outer circle of the air outlet side of the bearing cylinder, and a second platform used for machining deformation detection is arranged in the middle of the outer portion of the bearing cylinder. The preparation deformation control method comprises the steps of preparation front bearing cylinder deformation control, preparation process deformation control and thermal process deformation control, and the requirement for a gap between an inner runner of the whole circular bearing cylinder and a rotor moving blade is met. The corrosion resistance of the runner in the bearing cylinder is improved, and the product manufacturing cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace gas residual pressure recovery turbine power generation device (TRT), and in particular to a bearing cylinder for an energy recovery unit and a preparation deformation control method thereof. Background Art

[0002] The blast furnace gas waste pressure recovery turbine power generation device (TRT) is a secondary energy recovery device that converts the internal energy of the high-temperature and high-pressure gas generated by the blast furnace into mechanical energy or electrical energy to achieve energy recycling.

[0003] With the improvement of blast furnace smelting technology, the temperature of blast furnace gas entering the TRT unit has been reduced from 120-150℃ to 90-120℃. The reduction in blast furnace gas temperature will cause strong acidic liquid condensation on the flow channel side of the unit's cylinder, accelerating the corrosion of the flow channel surface in the cylinder. After the flow channel in the cylinder is corroded, the gaps between the moving blades, stationary blades and cylinder inside the unit will increase, and leakage between stages will cause the unit's power generation efficiency to decrease. The increased corrosion depth will reduce the unit's life and even affect the safe operation of the unit. The existing measure is to replace the cylinder inside the blast furnace gas residual pressure recovery turbine power generation device with cast stainless steel, but there are still the following disadvantages: 1) Affected by the working environment of the steel plant, the raw gas used has a complex composition, and stainless steel materials, especially in high Cl - 1) Intergranular corrosion is prone to occur in the environment; 2) The coal gas contains dust, and the low hardness of stainless steel leads to insufficient erosion resistance; 3) The cylinder size is large, and cast stainless steel is used as the whole, which has high manufacturing costs. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a bearing cylinder for an energy recovery unit and a method for controlling deformation of its preparation. Through the structure and preparation of the bearing cylinder for the energy recovery unit, the clearance requirements between the entire circular inner flow channel of the bearing cylinder and the rotor blades can be guaranteed, and the corrosion resistance of the inner flow channel of the bearing cylinder can be improved. At the same time, the thickness of the corrosion-resistant layer of the inner flow channel of the bearing cylinder can be controlled between 0.5-10mm, thereby greatly reducing the product manufacturing cost.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0006] A support cylinder for an energy recovery unit is assembled from an upper support cylinder half and a lower support cylinder half. The upper support cylinder half and the lower support cylinder half both include a support cylinder inner flow channel 1. A corrosion-resistant layer 2 is configured in a partial area on the outlet side of the support cylinder inner flow channel 1. A chamfer 3 is provided at the connection between the corrosion-resistant layer 2 and the support cylinder inner flow channel 1. The chamfer 3 is set to an angle of 45-60 degrees.

[0007] A first platform 6 is provided in the middle of the flow channel 1 in the support cylinder, and an adjustable support rod 8 is arranged inside the first platform 6. The adjustable support rod 8 is used to adjust the deformation of the flow channel 1 in the support cylinder. After the adjustment is completed, the adjustable support rod 8 needs to be removed.

[0008] The upper cylinder half body and the lower cylinder half body are joined together by four process bolts located at the dividing surface position in the cylinder.

[0009] A full circle of belt 5 for adding fastening tooling is arranged at the outer circumference of the air outlet side of the support cylinder.

[0010] The middle part of the outer portion of the support cylinder is provided with a second platform 7 for machining deformation detection.

[0011] The thickness of the corrosion-resistant layer 2 is 0.5-10 mm; the material of the corrosion-resistant layer 2 is a nickel-based high-temperature alloy.

[0012] A method for controlling the deformation of a bearing cylinder for an energy recovery unit comprises the following steps:

[0013] 1) Preparation of front bearing cylinder deformation control:

[0014] 1.1) At the mid-section position of the support cylinder, the upper support cylinder half and the lower support cylinder half are assembled by the process bolts 4;

[0015] 1.2) A full circle of belt 5 is set on the outer circle of the air outlet side of the cylinder, and the outer side of the belt 5 is controlled by adding fastening tooling to control processing deformation;

[0016] 1.3) An adjustable support rod 8 is arranged inside the first platform 6 in the middle of the flow channel 1 in the support cylinder, and the deformation of the flow channel 1 in the support cylinder is adjusted by the adjustable support rod 8;

[0017] 1.4) A second platform 7 is arranged at the middle part of the outer portion of the support cylinder for machining deformation detection;

[0018] 2) Deformation control during the manufacturing process:

[0019] 2.1) Pre-process the stationary blade holes in advance, and reserve a margin of 5-10mm on one side of the stationary blade holes;

[0020] 2.2) Select laser welding or cladding method to process the corrosion-resistant layer 2, and set the laser power, scanning speed, powder feeding speed, overlap rate, and spot diameter parameters;

[0021] 2.3) Set the welding or cladding path to avoid the stationary blade hole position;

[0022] 3) Thermal process deformation control:

[0023] 3.1) Heat treatment tooling: Before heat treatment, an adjustable support rod 8 is added to the first platform 6 next to the corrosion-resistant layer 2. The material of the adjustable support rod 8 is a high-temperature alloy with a high thermal expansion coefficient, including GH4169 and GH2130;

[0024] 3.2) Heat treatment equipment: Use a pre-vacuum furnace for heat treatment and stress relief treatment, and use a high-temperature, short-time insulation and segmented furnace cooling heat treatment stress relief process;

[0025] 4) Repair:

[0026] 4.1) Remove the adjustable support rod 8, and check the clearance between the intermediate surfaces of the cylinder to determine whether to increase the pre-tightening force setting of the fastening tooling. If the clearance between the intermediate surfaces is ≤0.1mm, no fastening tooling is required. If the clearance between the intermediate surfaces is >0.1mm, apply pre-tightening force to the fastening tooling to make the clearance ≤0.1mm.

[0027] 4.2) Remove the process bolt 4, use the dial gauge platform to align and readjust the processing reference, and complete the center surface polishing processing and the stationary blade hole processing.

[0028] In the step 2.2), the laser power is 1500-2400W; the overlap rate is ≥40%; the welding or scanning speed is 15-25mm / s, the spot diameter is 2-4mm, and the powder feeding speed when cladding is selected is 15-30g / min.

[0029] The step 2.3) uses two sets of robotic arms to perform symmetrical cladding in a circular manner from the center of the cylinder to reduce stress and deformation.

[0030] The step 3.2) of medium-high temperature short-time insulation and segmented furnace cooling is specifically as follows: heating rate: 100-150°C / hour; heating temperature: 620±20°C; insulation time: 1 hour±wall thickness / 100 hours; cooling curve: furnace cooling to 150-200°C before exiting the furnace.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) Since the flow channel in the bearing cylinder of the present invention is provided with a corrosion-resistant layer, the service life of the bearing cylinder can be effectively extended. At the same time, the thickness of the corrosion layer is relatively thin at 0.5-10 mm. Compared with the overall use of cast stainless steel, it greatly reduces the use of high Cr and Ni materials and significantly reduces the manufacturing cost;

[0033] 2) Since the preparation deformation control method of the present invention adopts the deformation control of the bearing cylinder before preparation, the deformation control of the preparation process and the deformation control of the thermal process, it can effectively prevent the deformation of the bearing cylinder and ensure the dimensional accuracy of the bearing cylinder;

[0034] 3) Due to the deformation control of the preparation process of the present invention, based on the thickness of the corrosion-resistant layer, a laser welding or cladding method with a small deformation is selected for processing; and according to the thickness requirements of the corrosion-resistant layer, the laser power, scanning speed, powder feeding speed, overlap rate, and spot diameter parameters are set, laser power: 1500-2400w; overlap rate: ≥40%; welding or scanning speed: 15-25mm / s, spot diameter 2-4mm, wherein the powder feeding speed when cladding is selected: 15-30g / min, so the welding or cladding amount is reduced;

[0035] 4) Since the preparation process of the present invention uses two sets of mechanical arms to perform cladding symmetrically and step by step from the center of the cylinder in a circular pattern during deformation control, stress and deformation are reduced, so the cladding quality is good;

[0036] 5) During the thermal process deformation control of the present invention, in order to control the deformation of the bearing cylinder, adjustable support rods are added on both sides of the corrosion-resistant area (corrosion-resistant layer 2) before heat treatment, and the material is a high-temperature alloy with a high thermal expansion coefficient, so the thermal process deformation control effect is good;

[0037] 6) Since the heat treatment equipment of the present invention uses a pre-vacuum furnace to perform heat treatment and stress relief treatment during the thermal process deformation control, the oxidation of the bearing cylinder surface is reduced;

[0038] 7) Since the thermal process deformation control of the present invention adopts a high-temperature short-time heat preservation and segmented furnace cooling heat treatment stress relief process, the heating rate is: 100-150°C / hour; heating temperature: 620±20°C; insulation time: 1 hour±wall thickness / 100 hours; cooling curve: furnace cooling to 150-200°C, so the stress relief effect is good;

[0039] In summary, the present invention ensures the clearance requirements between the entire circular bearing cylinder inner flow channel and the rotor moving blades; improves the corrosion resistance of the bearing cylinder inner flow channel, and at the same time can control the thickness of the corrosion-resistant layer of the bearing cylinder inner flow channel to between 0.5-10mm, thereby greatly reducing the product manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG. 1( a ) is a schematic diagram of the structure of the support cylinder of the present invention; FIG. 1( b ) is a schematic diagram of the preparation deformation control of the support cylinder of the present invention.

[0041] Figure 2 A flow chart of a deformation control method for preparing the present invention. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with embodiments and drawings.

[0043] Embodiment 1, referring to Figure 1(a) and Figure 1(b), a support cylinder for an energy recovery unit is assembled from an upper support cylinder half and a lower support cylinder half, the upper support cylinder half and the lower support cylinder half are joined by a process bolt 4 located at a dividing surface position in the support cylinder, a full circle of a belt 5 is provided on the outer circle of the air outlet side of the support cylinder, and a second platform 7 is provided in the middle part of the outer part of the support cylinder; the upper support cylinder half and the lower support cylinder half both include a flow channel 1 in the support cylinder, a corrosion-resistant layer 2 is provided in a partial area on the air outlet side of the flow channel 1 in the support cylinder, a chamfer 3 is provided at the junction of the corrosion-resistant layer 2 and the flow channel 1 in the support cylinder, the chamfer 3 is set to a 60° bevel angle, and the chamfer 3 is conducive to the implementation of the welding process and deformation control; a first platform 6 is provided in the middle part of the flow channel 1 in the support cylinder.

[0044] The thickness of the corrosion-resistant layer 2 is 5 mm; the material of the corrosion-resistant layer 2 is Inconel625.

[0045] Reference Figure 2 A method for controlling the deformation of a bearing cylinder for an energy recovery unit comprises the following steps:

[0046] 1) Referring to Figure 1(a) and Figure 1(b), prepare the deformation control of the front bearing cylinder:

[0047] 1.1) At the mid-face position of the support cylinder, the upper support cylinder half and the lower support cylinder half are assembled by the process bolt 4, and the single-side margin of the process bolt 4 is 4mm;

[0048] 1.2) A full circle of belt 5 is set on the outer circle of the air outlet side of the cylinder, and the outer side of the belt 5 is controlled by adding fastening tooling to control processing deformation;

[0049] 1.3) An adjustable support rod 8 is arranged inside the first platform 6 in the middle of the flow channel 1 in the cylinder, and the deformation of the flow channel 1 in the cylinder is adjusted by the adjustable support rod 8; the adjustable support rod 8 is made of carbon steel and is removed after processing;

[0050] 1.4) A second platform 7 is arranged at the middle part of the outer portion of the support cylinder for machining deformation detection;

[0051] 2) Deformation control during the manufacturing process:

[0052] 2.1) The stationary blade holes are pre-processed in advance. To ensure the tolerance requirements of the stationary blade holes, a 5mm margin is reserved on one side of the stationary blade holes;

[0053] 2.2) Based on the thickness of the corrosion-resistant layer 2 of 5 mm, a laser welding method with small deformation is selected to process the corrosion-resistant layer 2; according to the thickness requirements of the corrosion-resistant layer, the laser power, scanning speed, powder feeding speed, overlap rate, and spot diameter parameters are set to reduce the welding amount;

[0054] In this embodiment, the laser power of the base layer is 1800w, the welding speed is 20mm / s, the laser power of the subsequent filling layer is 2400w, the spot diameter is 3mm, the welding speed is 25mm / s, and the overlap rate is 50%;

[0055] 2.3) Set the welding or cladding path to avoid the position of the stationary blade holes and perform cladding in different areas to reduce stress and deformation;

[0056] In this embodiment, only the rear half of the support cylinder is welded, and the welding is carried out in a circular manner from right to left;

[0057] 3) Thermal process deformation control:

[0058] 3.1) Heat treatment tooling: Before heat treatment, an adjustable support rod 8 is added to the first platform 6 next to the corrosion-resistant layer 2. The material of the adjustable support rod 8 is a high-temperature alloy with a high thermal expansion coefficient, such as GH4169, to reduce the shrinkage of the bearing cylinder during the heat treatment process;

[0059] 3.2) Heat treatment equipment: Use pre-vacuum furnace for heat treatment and stress relief treatment, vacuum degree 1×10 -3 Pa, reduce the oxidation of the bearing cylinder surface; use high temperature short time insulation and segmented furnace cooling heat treatment stress relief process to eliminate welding stress;

[0060] The specific parameters of the high temperature short time heat preservation and staged furnace cooling in this embodiment are: heating rate: 120℃ / hour; heating temperature: 620℃; heat preservation time: 1 hour; cooling curve: furnace cooling to 200℃ and then out of the furnace;

[0061] 4) Repair:

[0062] 4.1) Remove the adjustable support rod 8, check the clearance between the bearing cylinder and the dividing surface to be 0.08mm, and no additional fastening tooling is required;

[0063] 4.2) Remove the process bolt 4, use the dial gauge platform to align and readjust the processing reference, and complete the center surface polishing processing and the stationary blade hole processing.

[0064] Beneficial effects of this embodiment: This embodiment ensures the clearance requirements between the entire circular bearing cylinder inner flow channel and the rotor moving blades; improves the corrosion resistance of the bearing cylinder inner flow channel, and at the same time can control the thickness of the corrosion-resistant layer of the bearing cylinder inner flow channel between 5±0.5mm, greatly reducing the product manufacturing cost; compared with the cast stainless steel bearing cylinder, the cost of this embodiment is reduced by 1 times; compared with ordinary cast steel and cast iron bearing cylinders, the service life of this embodiment is increased by 2.5 times.

[0065] Example 2, a cylinder structure for an energy recovery unit is similar to Example 1, except that the chamfer 3 is set to a 45° angle, the thickness of the corrosion-resistant layer 2 is changed to 0.5mm, the corrosion-resistant layer 2 is changed from the rear half of the cylinder to the entire flow channel, and the preparation method is changed to laser cladding; step 2.4) uses two sets of robotic arms to clad symmetrically in steps from the center of the cylinder in a circular manner; step 2.3) is changed to a base layer laser power of 1500w, a scanning speed of 15mm / s, a subsequent filling layer laser power of 2000w, a spot diameter of 2mm, and an overlap rate of 40%; powder feeding speed during cladding: 15g / min.

[0066] Beneficial effects of this embodiment: This embodiment ensures the clearance requirements between the flow channel in the entire circular bearing cylinder and the rotor blades, and the thickness of the corrosion-resistant layer in the flow channel in the bearing cylinder is controlled between 0.5±0.1mm; the corrosion resistance of the flow channel in the bearing cylinder is improved, and the product manufacturing cost is greatly reduced; compared with the cast stainless steel bearing cylinder, the cost of this embodiment is reduced by 2 times; compared with ordinary cast steel and cast iron bearing cylinders, the service life of this embodiment is increased by 2 times.

[0067] Example 3, a cylinder structure for an energy recovery unit is similar to Example 2, except that the chamfer 3 is set to a 50° angle, the thickness of the corrosion-resistant layer 2 is changed to 10mm, the corrosion-resistant layer 2 is changed from the rear half of the cylinder to the entire flow channel, and the preparation method is changed to laser cladding; step 2.4) uses two sets of robotic arms to clad symmetrically in steps from the center of the cylinder in a circular manner; step 2.3) is changed to a base layer laser power of 1500w, a scanning speed of 25mm / s, a subsequent filling layer laser power of 2400w, a spot diameter of 4mm, and an overlap rate of 45%; powder feeding speed during cladding: 30g / min; step 3.1) the material of the adjustable support rod 8 is GH2130.

[0068] Beneficial effects of this embodiment: This embodiment ensures the clearance requirements between the flow channel in the entire circular bearing cylinder and the rotor blades, and the thickness of the corrosion-resistant layer in the flow channel in the bearing cylinder is controlled between 10±1mm; the corrosion resistance of the flow channel in the bearing cylinder is improved, and the product manufacturing cost is greatly reduced; compared with the cast stainless steel bearing cylinder, the cost of this embodiment is reduced by 1.5 times; compared with ordinary cast steel and cast iron bearing cylinders, the service life of this embodiment is increased by 3 times.

Claims

1. A support cylinder for an energy recovery unit, characterized in that: The invention is assembled from an upper cylinder half body and a lower cylinder half body, each of which comprises a cylinder inner flow channel (1), a corrosion-resistant layer (2) is arranged on a part of the gas outlet side of the cylinder inner flow channel (1), a chamfer (3) is arranged at the junction between the corrosion-resistant layer (2) and the cylinder inner flow channel (1), and the chamfer (3) is set to an angle of 45-60 degrees.

2. The support cylinder for an energy recovery unit according to claim 1, characterized in that: A first platform (6) is provided in the middle of the flow channel (1) in the support cylinder. An adjustable support rod (8) is connected inside the first platform (6). The adjustable support rod (8) is used to adjust the deformation of the flow channel (1) in the support cylinder. After the adjustment is completed, the adjustable support rod (8) needs to be removed.

3. The support cylinder for an energy recovery unit according to claim 1, characterized in that: The upper support cylinder half body and the lower support cylinder half body are joined together by a process bolt (4) located at a dividing surface position in the support cylinder.

4. The support cylinder for an energy recovery unit according to claim 1, characterized in that: A full circle of belt (5) for adding a fastening tool is arranged at the outer circle of the air outlet side of the support cylinder.

5. The support cylinder for an energy recovery unit according to claim 1, characterized in that: The middle part of the outer portion of the support cylinder is provided with a second platform (7) for machining deformation detection.

6. The support cylinder for an energy recovery unit according to claim 1, characterized in that: The thickness of the corrosion-resistant layer (2) is 0.5-10 mm; the material of the corrosion-resistant layer (2) is a nickel-based high-temperature alloy.

7. A method for controlling deformation of a support cylinder for an energy recovery unit according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Preparation of deformation control of front bearing cylinder: 1.1) At the mid-section of the support cylinder, assemble the upper support cylinder half and the lower support cylinder half by means of process bolts (4); 1.2) A full circle of circumferential belt (5) is provided on the outer circumference of the air outlet side of the cylinder, and the outer side of the circumferential belt (5) is controlled to be deformed by adding fastening tooling; 1.3) An adjustable support rod (8) is arranged inside the first platform (6) in the middle of the flow channel (1) in the support cylinder, and the deformation of the flow channel (1) in the support cylinder is adjusted by the adjustable support rod (8); 1.4) A second platform (7) is arranged at the middle part of the outer portion of the support cylinder for machining deformation detection; 2) Deformation control during the manufacturing process: 2.1) Pre-process the stationary blade holes in advance, and reserve a margin of 5-10mm on one side of the stationary blade holes; 2.2) Select laser welding or cladding method to process the corrosion-resistant layer (2), and set the laser power, scanning speed, powder feeding speed, overlap rate, and spot diameter parameters; 2.3) Set the welding or cladding path to avoid the stationary blade hole position; 3) Thermal process deformation control: 3.1) Heat treatment tooling: before heat treatment, an adjustable support rod (8) is added to the first platform (6) next to the corrosion-resistant layer (2). The material of the adjustable support rod (8) is a high-temperature alloy with a high thermal expansion coefficient, including GH4169 or GH2130; 3.2) Heat treatment equipment: Use a pre-vacuum furnace for heat treatment and stress relief treatment, and use a high-temperature, short-time insulation and segmented furnace cooling heat treatment stress relief process; 4) Repair: 4.1) Remove the adjustable support rod (8), and check the clearance between the intermediate surfaces of the bearing cylinder to determine whether to increase the pre-tightening force setting of the fastening tooling. If the clearance between the intermediate surfaces is ≤0.1mm, it is not necessary to increase the fastening tooling. If the clearance between the intermediate surfaces is >0.1mm, apply the pre-tightening force to the fastening tooling to make the clearance ≤0.1mm. 4.2) Remove the process bolts (4), use the dial gauge to align and then readjust the processing datum to complete the center surface polishing and stationary blade hole processing.

8. The method for controlling deformation of the production process according to claim 7, characterized in that: In the step 2.2), the laser power is 1500-2400W; the overlap rate is ≥40%; the welding or scanning speed is 15-25mm / s, the spot diameter is 2-4mm, and the powder feeding speed when cladding is selected is 15-30g / min.

9. The method for controlling deformation during preparation according to claim 7, characterized in that: The step 2.3) uses two sets of robotic arms to perform symmetrical cladding in a circular manner from the center of the cylinder to reduce stress and deformation.

10. The method for controlling deformation of the production process according to claim 7, characterized in that: The step 3.2) of medium-high temperature short-time insulation and segmented furnace cooling is specifically as follows: heating rate: 100-150°C / hour; heating temperature: 620±20°C; insulation time: 1 hour±wall thickness / 100 hours; cooling curve: furnace cooling to 150-200°C before exiting the furnace.

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