Energy recovery unit cylinder and method for controlling deformation of the same

Abstract

An energy recovery unit cylinder and a preparation deformation control method thereof, the cylinder is assembled by an upper cylinder half and a lower cylinder half, the upper cylinder half and the lower cylinder half both include a cylinder inner flow channel, a corrosion-resistant layer is added to a part of an air outlet side of the cylinder inner flow channel, a chamfer is arranged at a joint between the corrosion-resistant layer and the cylinder inner flow channel, the chamfer is beneficial to welding process implementation and deformation control, a first platform is arranged at a middle part of the cylinder inner flow channel, an adjustable support rod is connected to the first platform, the upper cylinder half and the lower cylinder half are combined by process bolts, a surrounding band for increasing fastening tools is arranged on an outer circle of an air outlet side of the cylinder, a second platform for processing deformation detection is arranged at a middle part of an outer part of the cylinder; the preparation deformation control method includes cylinder deformation control before preparation, preparation process deformation control and thermal process deformation control, and ensures a clearance requirement between the entire circular cylinder inner flow channel and a rotor blade; the corrosion-resistant capability of the cylinder inner flow channel is improved, and the product manufacturing cost is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of blast furnace gas pressure recovery turbine generator (TRT), and particularly relates to a cylinder for energy recovery unit and a preparation deformation control method thereof. BACKGROUND

[0002] The blast furnace gas pressure recovery turbine generator (TRT) is a secondary energy recovery device, which converts the internal energy of the high-temperature and high-pressure gas generated by the blast furnace into mechanical energy or electrical energy, so as to realize the cyclic utilization of energy.

[0003] With the improvement of the blast furnace smelting process, the temperature of the blast furnace gas entering the TRT unit is reduced from 120-150 DEG C to 90-120 DEG C. The reduction of the temperature of the blast furnace gas will cause strong acid liquid condensation on the side of the flow passage of the cylinder, accelerate the corrosion of the flow passage surface in the cylinder, and increase the gap between the dynamic blade, the static blade and the cylinder after the corrosion of the flow passage in the cylinder. The leakage between the stages will reduce the power generation efficiency of the unit, and the increase of the corrosion depth will reduce the service life of the unit and even affect the safe operation of the unit. The existing measure is to change the cylinder in the TRT unit into a cast stainless steel, but there are still the following shortcomings: 1) due to the influence of the working environment of the steel plant, the composition of the raw gas used is complex, the intergranular corrosion of the stainless steel material is easy to occur, especially in the high Cl - environment; 2) the gas contains dust, and the low hardness of the stainless steel material leads to insufficient erosion resistance; 3) the size of the cylinder is large, and the overall cast stainless steel material is selected, so that the manufacturing cost is high. SUMMARY

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a cylinder for energy recovery unit and a preparation deformation control method thereof. Through the structure and preparation of the cylinder for energy recovery unit, the gap requirements between the entire circular cylinder inner flow passage and the rotor dynamic blade can be guaranteed, the corrosion resistance of the cylinder inner flow passage can be improved, and the thickness of the corrosion resistant layer in the cylinder inner flow passage can be controlled between 0.5-10 mm, so that the product manufacturing cost is greatly reduced.

[0005] In order to solve the above-mentioned technical problems, the present application adopts the following technical solutions:

[0006] A cylinder for energy recovery unit is assembled by an upper cylinder half and a lower cylinder half, the upper cylinder half and the lower cylinder half both include a cylinder inner flow passage 1, a corrosion resistant layer 2 is arranged on the gas outlet side of the cylinder inner flow passage 1, a chamfer 3 is arranged at the joint between the corrosion resistant layer 2 and the cylinder inner flow passage 1, and the chamfer 3 is arranged as a 45-60 DEG inclined angle.

[0007] The first platform 6 is arranged in the middle part of the inner flow channel 1, and an adjustable supporting rod 8 is arranged in the first platform 6, which is used for adjusting the deformation of the inner flow channel 1, and the adjustable supporting rod 8 needs to be removed after the adjustment is completed.

[0008] The upper cylinder half and the lower cylinder half are combined by the process bolt 4 located at the middle split surface of the cylinder.

[0009] The surrounding band 5 for increasing the fastening tool is arranged on the outer circle of the gas outlet side of the cylinder.

[0010] The second platform 7 for processing deformation detection is arranged in the middle part of the outer part of the cylinder.

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

[0012] A preparation deformation control method of a cylinder for an energy recovery unit, comprising the following steps:

[0013] 1) Preparation of the cylinder before deformation control:

[0014] 1.1) The upper cylinder half and the lower cylinder half are combined by the process bolt 4 located at the middle split surface of the cylinder.

[0015] 1.2) The surrounding band 5 is arranged on the outer circle of the gas outlet side of the cylinder, and the outer side of the surrounding band 5 is controlled by increasing the fastening tool to control the processing deformation.

[0016] 1.3) The adjustable supporting rod 8 is arranged in the first platform 6 in the middle part of the inner flow channel 1, and the adjustable supporting rod 8 is used for adjusting the deformation of the inner flow channel 1.

[0017] 1.4) The second platform 7 for processing deformation detection is arranged in the middle part of the outer part of the cylinder.

[0018] 2) Preparation process deformation control:

[0019] 2.1) The static blade hole is pre-processed in advance, and a single-side allowance of 5-10 mm is reserved.

[0020] 2.2) The laser welding or cladding method is selected for processing the corrosion-resistant layer 2, and the laser power, scanning speed, powder feeding speed, overlap rate and spot diameter parameters are set.

[0021] 2.3) The welding or cladding path is set to avoid the static blade hole position.

[0022] 3) Thermal process deformation control:

[0023] 3.1) Heat treatment tooling: adjustable support rods 8 are added in the first platform 6 beside the corrosion-resistant layer 2 before heat treatment, and the material of the adjustable support rods 8 is selected from high-temperature alloys with high thermal expansion coefficients, including GH4169 and GH2130;

[0024] 3.2) Heat treatment equipment: a pre-vacuum furnace is selected to perform stress relief treatment, and a high-temperature short-time holding segmented furnace cooling heat treatment stress relief process is selected;

[0025] 4) Modification:

[0026] 4.1) Remove the adjustable support rods 8, and determine whether to increase the pre-tightening force of the fastening tooling by checking the gap between the middle split surfaces in the cylinder, when the gap is ≤0.1mm, the pre-tightening force of the fastening tooling does not need to be increased, and when the gap is >0.1mm, the pre-tightening force of the fastening tooling is applied to make the gap ≤0.1mm;

[0027] 4.2) Remove the process bolts 4, and adjust the machining reference after alignment on the dial platform, and complete the light machining of the middle split surface and the machining of the static blade hole.

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

[0029] Two groups of mechanical arms are used in the step 2.3) to melt and clad in steps from the center of the cylinder to the circumference, thereby reducing stress and deformation.

[0030] The high-temperature short-time holding segmented furnace cooling in the step 3.2) is specifically as follows: the heating rate is 100-150℃ / hour, the heating temperature is 620±20℃, the holding time is 1 hour±wall thickness / 100 hours, and the cooling curve is furnace cooling to 150-200℃ and then taken out of the furnace.

[0031] Compared with the prior art, the beneficial effects of the present application are:

[0032] 1) Since the inner flow passage of the cylinder in the present application is provided with a corrosion-resistant layer, the service life of the cylinder can be effectively prolonged, and since the corrosion-resistant layer has a thickness of 0.5-10mm, which is relatively thin, compared with the use of whole cast stainless steel material, the use of high-Cr and high-Ni materials is greatly reduced, and the manufacturing cost is greatly reduced;

[0033] 2) Since the deformation control method in the present application adopts cylinder deformation control before preparation, process deformation control during preparation, and thermal process deformation control, the cylinder deformation can be effectively prevented, and the size accuracy of the cylinder can be ensured;

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

[0035] 4) due to the deformation control of the preparation process of the present application, two groups of mechanical arms are used to melt and clad in steps according to the circumference from the central symmetry of the cylinder, so as to reduce the stress and deformation, and therefore the cladding quality is good;

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

[0037] 6) due to the deformation control of the thermal process of the present application, the heat treatment equipment is selected as a pre-vacuum furnace for heat treatment and stress relief treatment, so as to reduce the oxidation of the cylinder surface;

[0038] 7) due to the deformation control of the thermal process of the present application, a high-temperature short-time holding segmented furnace cooling heat treatment stress relief process is selected, the heating rate is 100-150℃ / h, the heating temperature is 620±20℃, the holding time is 1h±wall thickness / 100h, and the cooling curve is furnace cooling to 150-200℃ and then taken out, so the stress relief effect is good;

[0039] In summary, the present application guarantees the requirements of the entire circular cylinder inner flow passage and the rotor blade gap; improves the corrosion resistance of the cylinder inner flow passage, and at the same time, the thickness of the corrosion-resistant layer of the cylinder inner flow passage can be controlled between 0.5-10mm, which greatly reduces the product manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0040] Fig. 1(a) is a structural schematic view of the cylinder of the present application; Fig. 1(b) is a preparation deformation control schematic view of the cylinder of the present application.

[0041] Figure 2 The flow chart of the preparation deformation control method of the present application. DETAILED DESCRIPTION

[0042] The present application will be described in detail below in combination with the embodiments and the drawings.

[0043] Embodiment 1, referring to Fig. 1(a) and Fig. 1(b), a cylinder for energy recovery unit is assembled by an upper cylinder half and a lower cylinder half, the upper cylinder half and the lower cylinder half are combined by process bolts 4 at the middle surface position of the cylinder, a whole-circle surrounding band 5 is arranged at the outer circle of the gas outlet side of the cylinder, a second platform 7 is arranged at the middle part of the outer part of the cylinder; the upper cylinder half and the lower cylinder half each include a cylinder inner flow channel 1, a corrosion-resistant layer 2 is arranged at the part area of the gas outlet side of the cylinder inner flow channel 1, a chamfer 3 is arranged at the joint of the corrosion-resistant layer 2 and the cylinder inner flow channel 1, the chamfer 3 is arranged as a 60° bevel, the chamfer 3 is beneficial to the welding process implementation and deformation control; a first platform 6 is arranged at the middle part of the cylinder inner flow channel 1.

[0044] The corrosion-resistant layer 2 has a thickness of 5 mm; the corrosion-resistant layer 2 is made of Inconel 625.

[0045] Referring to Figure 2 A deformation control method for preparing a cylinder for an energy recovery unit, comprising the following steps:

[0046] 1) Referring to Fig. 1(a) and Fig. 1(b), deformation control of the cylinder before preparation:

[0047] 1.1) The upper cylinder half and the lower cylinder half are combined by process bolts 4 at the middle surface position of the cylinder, the process bolts 4 have a single-side allowance of 4 mm;

[0048] 1.2) A whole-circle surrounding band 5 is arranged at the outer circle of the gas outlet side of the cylinder, the outer side of the surrounding band 5 is controlled for processing deformation by increasing fastening tools;

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

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

[0051] 2) Deformation control of the preparation process:

[0052] 2.1) The stator hole is pre-processed in advance, a single-side allowance of 5 mm is reserved for the stator hole to ensure the stator hole tolerance requirement;

[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 for processing the corrosion-resistant layer 2; according to the thickness requirement of the corrosion-resistant layer, parameters such as laser power, scanning speed, powder feeding speed, overlap rate and spot diameter are set to reduce the welding amount;

[0054] 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 stator blade hole position, and divide the cladding to reduce stress and deformation;

[0056] In this embodiment, only the rear half of the bearing cylinder is welded, and the welding is performed in the circumferential direction from right to left.

[0057] 3) Hot process deformation control:

[0058] 3.1) Heat treatment tooling: adjustable support rods 8 are added in the first platform 6 beside the corrosion-resistant layer 2 before heat treatment, the material of the adjustable support rods 8 is selected from high-temperature alloys with high thermal expansion coefficients, GH4169 is selected, and the shrinkage of the bearing cylinder during heat treatment is reduced.

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

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

[0061] 4) Modification:

[0062] 4.1) Remove the adjustable support rods 8, check the gap between the middle sections of the bearing cylinder to be 0.08mm, and do not need to add fastening tooling.

[0063] 4.2) Remove the process bolts 4, use the dialing platform to align, adjust the machining reference again, complete the light machining of the middle section and the machining of the stator blade hole.

[0064] The beneficial effects of this embodiment are: this embodiment ensures the gap requirements between the inner flow passage of the entire circular bearing cylinder and the rotor blade; improves the corrosion resistance of the inner flow passage of the bearing cylinder, and at the same time, the thickness of the corrosion-resistant layer of the inner flow passage of the bearing cylinder can be controlled between 5±0.5mm, greatly reducing the product manufacturing cost; compared with the cast stainless steel bearing cylinder, the cost is reduced by 1 times; compared with the ordinary cast steel and cast iron bearing cylinder, the service life is improved by 2.5 times.

[0065] Example 2, a kind of energy recovery unit with cylinder structure and implementation 1 similar, only chamfer 3 is set to 45 ° bevel, the thickness of corrosion-resistant layer 2 is changed to 0.5 mm, corrosion-resistant layer 2 is changed to the entire flow passage from the rear half of the cylinder, and the preparation method is changed to laser cladding;Step 2.4) is adopted by two groups of mechanical arms, and is cladded in steps according to the circumference from the central symmetry of the cylinder;Change step 2.3) to the laser power of the primer layer is 1500w, the scanning speed is 15mm / s, the subsequent filling layer laser power is 2000w, the spot diameter is 2mm, and the overlap rate is 40%;The powder feeding speed during cladding is 15g / min.

[0066] The beneficial effects of the present embodiment are: the present embodiment ensures the entire circular cylinder inner flow passage and rotor blade gap requirements, the corrosion-resistant layer thickness in the cylinder inner flow passage is controlled between 0.5±0.1mm;Improve the corrosion resistance of the cylinder inner flow passage, greatly reduce the product manufacturing cost;Compared with the cast stainless steel cylinder, the cost is reduced by 2 times;Compared with ordinary cast steel and cast iron cylinder, the service life is improved by 2 times.

[0067] Example 3, a kind of energy recovery unit with cylinder structure and implementation 2 similar, only chamfer 3 is set to 50 ° bevel, the thickness of corrosion-resistant layer 2 is changed to 10 mm, corrosion-resistant layer 2 is changed to the entire flow passage from the rear half of the cylinder, and the preparation method is changed to laser cladding;Step 2.4) is adopted by two groups of mechanical arms, and is cladded in steps according to the circumference from the central symmetry of the cylinder;Change step 2.3) to the laser power of the primer layer is 1500w, the scanning speed is 25mm / s, the subsequent filling layer laser power is 2400w, the spot diameter is 4mm, and the overlap rate is 45%;The powder feeding speed during cladding is 30g / min;Step 3.1) can adjust the support rod 8 material to choose GH2130.

[0068] The beneficial effects of the present embodiment are: the present embodiment ensures the entire circular cylinder inner flow passage and rotor blade gap requirements, the corrosion-resistant layer thickness in the cylinder inner flow passage is controlled between 0.5±0.1mm;Improve the corrosion resistance of the cylinder inner flow passage, greatly reduce the product manufacturing cost;Compared with the cast stainless steel cylinder, the cost is reduced by 2 times;Compared with ordinary cast steel and cast iron cylinder, the service life is improved by 2 times.

Claims

1. A method for controlling the deformation during the fabrication of a bearing cylinder for an energy recovery unit, characterized in that: A bearing cylinder for an energy recovery unit is assembled from an upper bearing cylinder half and a lower bearing cylinder half. Both the upper and lower bearing cylinder half include an inner flow channel (1). A corrosion-resistant layer (2) is provided in a portion of the outlet side of the inner flow channel (1). A chamfer (3) is provided at the junction of the corrosion-resistant layer (2) and the inner flow channel (1). The chamfer (3) is set at a 45-60° bevel angle. The aforementioned deformation control method includes the following steps: 1) Controlling the deformation of the front bearing cylinder during manufacturing: 1.1) At the split position in the bearing cylinder, the upper bearing cylinder half and the lower bearing cylinder half are joined together by process bolts (4); 1.2) A full-circle circumference band (5) is set at the outer circle of the air outlet side of the bearing cylinder. The deformation of the outer side of the circumference band (5) is controlled by adding fastening fixtures. 1.3) An adjustable support rod (8) is installed inside the first platform (6) in the middle part of the flow channel (1) of the bearing cylinder, and the deformation of the flow channel (1) of the bearing cylinder is adjusted by the adjustable support rod (8); 1.4) A second platform (7) is configured in the middle of the outer part of the bearing cylinder for processing deformation detection; 2) Control of deformation in the preparation process: 2.1) Pre-process the stationary vane hole in advance, leaving a 5-10mm allowance on each side of the stationary vane hole; 2.2) Select laser welding or cladding method to process the corrosion-resistant layer (2), and set the parameters of laser power, scanning speed, powder feeding speed, overlap rate and spot diameter; 2.3) Set the welding or cladding path to avoid the location of the stationary blade hole; 3) Thermal process deformation control: 3.1) Heat treatment fixture: 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 coefficient of thermal expansion, including GH4169 or GH2130. 3.2) Heat treatment equipment: A pre-vacuum furnace is selected for heat treatment stress relief, and a high-temperature short-time heat preservation and segmented furnace cooling heat treatment stress relief process is selected. 4) Shaping: 4.1) Remove the adjustable support rod (8), and determine whether to add a pre-tightening force setting for the fastening fixture by checking the gap between the middle surfaces of the bearing cylinder. When the gap between the middle surfaces is ≤0.1mm, no fastening fixture needs to be added. When the gap between the middle surfaces is >0.1mm, apply a pre-tightening force to the fastening fixture to make the gap ≤0.1mm. 4.2) Remove the process bolts (4), readjust the machining reference after aligning with the dial gauge platform, and complete the machining of the center split surface and the machining of the stationary leaf hole.

2. The deformation control method according to claim 1, characterized in that: The corrosion-resistant layer (2) has a thickness of 0.5-10 mm; the material of the corrosion-resistant layer (2) is a nickel-based high-temperature alloy.

3. The deformation control method according to claim 1, characterized in that, In step 2.2), the laser power is 1500~2400w; the overlap rate is ≥40%; the welding or scanning speed is 15~25mm / s, and the spot diameter is 2~4mm. The powder feeding speed during cladding is 15~30g / min.

4. The deformation control method according to claim 1, characterized in that: Step 2.3) uses two sets of robotic arms to symmetrically melt and coat the cylinder in a circular manner from the center, thereby reducing stress and deformation.

5. The deformation control method according to claim 1, characterized in that, In step 3.2), the high-temperature short-time heat preservation and segmented furnace cooling are as follows: heating rate: 100~150℃ / hour; heating temperature: 620±20℃; heat preservation time: 1 hour ± wall thickness / 100 hours; cooling curve: furnace cooled to 150-200℃ before exiting the furnace.

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