CN114700681A - Convection heating device for hot tightening of split bolt in cylinder and use method thereof - Google Patents
Convection heating device for hot tightening of split bolt in cylinder and use method thereof Download PDFInfo
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- CN114700681A CN114700681A CN202210386090.7A CN202210386090A CN114700681A CN 114700681 A CN114700681 A CN 114700681A CN 202210386090 A CN202210386090 A CN 202210386090A CN 114700681 A CN114700681 A CN 114700681A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P11/00—Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for
- B23P11/02—Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for by first expanding and then shrinking or vice versa, e.g. by using pressure fluids; by making force fits
- B23P11/025—Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for by first expanding and then shrinking or vice versa, e.g. by using pressure fluids; by making force fits by using heat or cold
Abstract
The invention discloses a convection heating device for hot tightening of split bolts in a cylinder and a use method thereof, wherein the convection heating device comprises: one end of the air inlet base cylinder is provided with an air inlet, and the other end of the air inlet base cylinder is a closed end; a plurality of air outlet through holes are formed in the preset part, close to the closed end, of the air inlet basic cylinder; a first flow channel is arranged in the air inlet base cylinder; the outlet sleeve is provided with an inlet and an outlet; the gas inlet of the gas inlet basic cylinder is used for introducing gas at a first preset temperature; the outer wall surface of the air inlet base cylinder and the inner wall surface of the column core of the bolt to be hot-tightened form a second flow channel; and the plurality of air outlet through holes are communicated with the outlet of the outlet sleeve sequentially through the second flow channel and the inlet of the outlet sleeve. According to the convection heating device, the bolt is heated by utilizing the convection heat exchange between the high-temperature gas and the inner surface of the bolt heating section, and compared with the traditional resistance rod heating mode, the convection heating device is safer and more efficient.
Description
Technical Field
The invention belongs to the technical field of cylinder split sealing, and particularly relates to a convection heating device for hot tightening of split bolts in a cylinder and a using method thereof.
Background
The cylinder of the steam turbine is the largest and most complex steel casting needing to be processed in the steam turbine and is generally divided into an upper half cylinder body and a lower half cylinder body, and the horizontal joint surface of the upper half cylinder body and the lower half cylinder body is called a split surface; the split surfaces of the existing steam turbine and gas turbine cylinders are usually connected by bolts, and the bolts need to be tightened by heat in the assembling process of the bolts due to the large size of the bolts, so that the bolts can obtain enough pretightening force.
In the existing process method for hot tightening the bolt, the bolt is usually heated by a resistance heating rod, the heating process of a single bolt is generally about 10-20 minutes, the heating time of a single cylinder for a whole circle of bolt is usually more than 4 hours, and the construction period can reach about 3-4 days when the bolt of the whole unit is heated; in addition, in the heating process, due to the fact that the structure of the resistor body is uneven or the resistor rod is not placed, uneven bolt heating and abrasion are easily caused, and the problem that the cylinder deforms due to uneven bolt fastening exists.
Disclosure of Invention
The invention aims to provide a convection heating device for hot tightening of split bolts in a cylinder and a using method thereof, so as to solve one or more technical problems. The convection heating device can realize bolt heating by utilizing the convection heat exchange between high-temperature gas and the inner surface of the bolt heating section on the premise of ensuring the safety of the bolt thread section, and is safer and more efficient compared with the traditional resistance rod heating mode.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a convection heating device for hot tightening of split bolts in a cylinder, which comprises:
the air inlet base cylinder is provided with an air inlet at one end and a closed end at the other end; a plurality of air outlet through holes are formed in the preset part, close to the closed end, of the air inlet basic cylinder; a first flow channel is arranged in the air inlet base cylinder;
an outlet sleeve provided with an inlet and an outlet;
the gas inlet of the gas inlet basic cylinder is used for introducing gas at a first preset temperature; the air inlet base cylinder is used for being installed in a column core of a bolt to be heated and tightened, an air inlet of the air inlet base cylinder is arranged outside the column core of the bolt to be heated and tightened, and a second flow channel is formed by the outer wall surface of the air inlet base cylinder and the inner wall surface of the column core of the bolt to be heated and tightened; the outlet sleeve is sleeved outside the air inlet of the air inlet base cylinder and used for plugging an outlet of a column core of the bolt to be thermally tightened;
the air inlet sequentially passes through the first flow channel, the plurality of air outlet through holes, the second flow channel and the inlet of the outlet sleeve and the outlet of the outlet sleeve, and gas introduced into the second flow channel is used for heating the bolts to be heated to a second preset temperature to realize heat fastening.
In a further development of the device according to the invention, the gas is air; the air inlet of the air inlet basic cylinder is filled with air at the air flow rate of 5-7 m/s, and the air pressure is 1.5-2 times of atmospheric pressure.
The device is further improved in that the first preset temperature is 250-450 ℃.
The device is further improved in that the second preset temperature is 200-400 ℃.
The device of the invention is further improved in that the air inlet base cylinder is used for being installed in the column core of the bolt to be hot-tightened, and the closed end of the air inlet base cylinder is used for being installed in the column core of the bolt to be hot-tightened in an inserting mode.
The device of the invention is further improved in that the outer wall surface of the air inlet basic cylinder is provided with an annular boss part for sleeving the outlet sleeve.
The device is further improved in that a plurality of air outlet through holes are formed in the preset position, close to the closed end, of the air inlet base cylinder, specifically, the plurality of air outlet through holes are formed in a plurality of preset cross sections, close to the closed end, of the air inlet base cylinder, and the air outlet through holes in each cross section are uniformly distributed along the circumferential direction.
The device of the invention is further improved in that the air inlet basic cylinder is of a straight cylinder structure; and the outlet sleeve and the air inlet part of the air inlet basic cylinder are made of heat insulating materials.
The invention provides a convection heating system for hot tightening of split bolts in a cylinder, which comprises a plurality of convection heating devices; the plurality of convection heating devices adopt the same air source and are used for being simultaneously and respectively inserted into the column cores of the plurality of bolts to be heated and tightened of the split surfaces in the air cylinder.
The invention provides a using method of a convection heating device for hot tightening of a split bolt in a cylinder, which comprises the following steps of:
installing an air inlet base cylinder in a column core of a bolt to be thermally tightened, wherein an air inlet of the air inlet base cylinder is arranged outside the column core of the bolt to be thermally tightened, and a second flow channel is formed by the outer wall surface of the air inlet base cylinder and the inner wall surface of the column core of the bolt to be thermally tightened;
sleeving an outlet sleeve outside an air inlet of the air inlet base cylinder, and plugging an outlet of a column core of the bolt to be thermally tightened;
gas at a first preset temperature is introduced through the gas inlet of the gas inlet basic cylinder, the gas enters the second flow channel through the first flow channel and the gas outlet through hole, the gas entering the second flow channel is heated, the bolt to be hot-tightened is hot-tightened to a second preset temperature, and the gas after heat exchange is led out through the outlet of the outlet sleeve.
Compared with the prior art, the invention has the following beneficial effects:
based on the technical problems that the existing bolt heating method is very complicated and consumes a large amount of time and labor, the invention particularly provides a convection heating device for hot tightening of split bolts in a cylinder; the bolt convection heating pipe structure can accelerate the heating process of bolts, shorten the overhaul time of a unit and improve the running safety of the unit. Compared with the resistance heating rod in the prior art, the heating device provided by the invention can heat the bolt more uniformly, and can greatly reduce the abrasion caused by nonuniform heating; this heating device can a plurality of same supporting devices of connection and simultaneous working, can greatly shorten the heating process of whole cylinder bolt, raises the efficiency.
The device adopts a mode of connecting two sleeve structures, can realize quick installation in a bolt structure, and has simple structure and convenient assembly and disassembly.
The device of the invention only needs one high-temperature pressure gas tank and one recovery tank as the matching equipment, and has low matching cost.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; it is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a schematic view of the installation position of a convection heating device in a cylinder bolt in an embodiment of the present invention;
FIG. 2 is a schematic illustration of the location of the bolts and convection heating device in an embodiment of the present invention;
FIG. 3 is an exploded view of a convective heating arrangement for hot-up of a split bolt in a cylinder according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a convection heating device for hot-tightening of split bolts in a cylinder according to an embodiment of the present invention;
FIG. 5 is a schematic cross-sectional view of a convective heating arrangement for hot-up of a split bolt in a cylinder according to an embodiment of the present invention;
FIG. 6 is a schematic view of the air flow of a cross-bolt hot-fastened convection heating apparatus for use in a cylinder in accordance with an embodiment of the present invention during operation;
FIG. 7 is a diagram illustrating the results of a numerical simulation process in accordance with an embodiment of the present invention;
in the figure, 100, the cylinder outer cylinder; 200. the cylinder is connected with a nut; 300. a cylinder connecting bolt; 400. a convection heating device; 401. an intake base cylinder; 402. an outlet sleeve;
1. an air intake section; 2. air supply mesh; 3. a closing section; 4. an outlet rectifying section; 5. and an air outlet section.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in other sequences than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1 to 5, a convection heating device for a split bolt hot-fastening in a cylinder according to an embodiment of the present invention, specifically, a bolt convection heating tube structure in a cylinder of a steam turbine or a gas turbine, which can be directly inserted into a stud core of a bolt of the cylinder, and the structural size of the bolt convection heating tube structure can be determined according to the size of the stud in a cooling state of the cylinder, so as to facilitate installation; wherein, the mounting position can be seen in fig. 1 and 2, the cylinder outer casing 100 is fixed by the cylinder connecting bolt 300 and the cylinder connecting nut 200; the structure of the convection heating apparatus 400 can be seen in fig. 3 to 5.
The convection heating device for the hot tightening of the split bolt in the cylinder mainly comprises an air inlet basic cylinder 401 and an outlet sleeve 402; wherein, the air inlet basic cylinder 401 consists of three substructures of an air inlet section 1, an air inlet mesh 2 and a closed section 3; the outlet sleeve 402 is composed of two substructures, an outlet rectifying section 4 and an outlet section 5.
The air inlet basic cylinder 401 is used for introducing high-temperature gas with a first preset temperature, so that the high-temperature gas can be quickly introduced into the device; during use, high-temperature gas enters the gas inlet basic cylinder 401 from a first flow passage in the cylinder and flows out from a second flow passage formed by the outer wall of the cylinder and the bolts, so that the gas inlet basic cylinder 401 also plays a role in keeping the temperature of the gas in the heating pipe outlet sleeve 402; the basic section of thick bamboo 401 of admitting air is with the runner that high-temperature gas leading-in section of thick bamboo outer wall and bolt constitute for high-temperature gas heats the bolt. Specifically, the air inlet section 1 may be a long cylindrical metal part, which is located inside the whole device and does not contact with the bolts of the steam turbine during assembly, the air inlet section 1 is divided into two sections by a protruding ring structure, the outer section and the protruding ring structure are located outside the bolts after assembly, and the whole structure is kept concentric with the bolts. The structure part outside the bolt of the air inlet section 1 is used for receiving high-temperature gas introduced by the high-pressure tank and guiding the gas to the air feeding mesh 2.
When the device of the embodiment of the invention operates, the structural part of the air inlet section 1 in the bolt keeps heat exchange with the gas outside the air inlet section 1, and the protruding annular structure is used for matching and sealing with the outlet sleeve 402. The air supply mesh holes 2 are arranged at the tail end of the air inlet section 1, namely the tail end of the bolt for heating, are uniformly distributed along the circumferential direction of the cylinder and are formed by a plurality of layers of arranged holes, and are used for uniformly draining high-temperature air flow led in by the air inlet section 1 to a flow channel formed by the outer wall of the cylinder and the inner wall of the bolt in the air inlet section 1, the closed section 3 is arranged at the tail end of the air inlet section 1 and is of a solid metal structure, the end face of the closed section 3 is level with the end face of the bolt after assembly and slightly exceeds the end face of the bolt, the size of the closed section 3 is slightly smaller than the diameter of the bolt and is used for closing the outlet section, so that the strength of the integral structure of the air inlet basic cylinder 401 is maintained, and the air inlet basic cylinder is convenient to position and install due to the large size of the air inlet basic cylinder.
The outlet sleeve 402 is used for guiding out the gas after the bolt is heated, so that the gas flows into the low-pressure tank for recycling, and the use cost is reduced; wherein, export rectifying section 4 is the drum structure, and its assembly back part is located the bolt outside, and the part is located inside, and its internal diameter on the top is less, and then closely cooperates with the protruding cyclic annular structure of section of admitting air 1 for gas drainage behind the heating bolt to the section of giving vent to anger 5, and form closely cooperating with section of admitting air 1, avoid high-temperature gas's revealing, improve the security of device and reduce energy loss, the section of giving vent to anger 5 sets up on the cylinder side of bolt outside export rectifying section 4 to communicate with each other with export rectifying section 4, be used for exporting the gas in the rectifying section 4 of exporting to in the low-pressure pipe.
In the embodiment of the invention, the type and the temperature of the required gas are limited in order to enable the device to complete the heating function of the bolt in a short time and comprehensively consider the cost. The inflow gas of the device is generally air, the highest temperature is higher than the temperature to be heated of the bolt, generally 250-450 ℃, the flow velocity of a given gas inlet is 5-7 m/s and the pressure is 1.5-2 times of atmospheric pressure due to different bolt hole diameters.
The working principle of the device provided by the embodiment of the invention comprises the following steps: after the device is started, the temperature of the inner wall surface of the bolt reaches the temperature to be heated by high-temperature gas, then the inner wall surface of the bolt conducts heat to the inside to gradually increase the temperature and expand the inner wall surface to a certain length, and then an upper nut and a lower nut of the stud bolt or a nut on the wire-planting bolt are screwed up to enhance the pretightening force of the stud bolt; during disassembly, the heating device is inserted into the central hole of the bolt according to the steps during installation to heat and extend the bolt until the tightening force disappears, and the nut can not be unscrewed and screwed out. Because the device is simple in structure and easy to manufacture, the devices required by all the bolts are manufactured at lower cost, and connection heating is carried out simultaneously, after a certain bolt reaches the temperature requirement, the bolt device can be closed, and relevant operation is carried out. Therefore, the invention can shorten the construction period of bolt maintenance of the whole unit by a mode of simultaneous operation with lower cost.
In the embodiment of the invention, the metal materials of the air supply network structure and the closed section 3 in the air inlet section 1 of the air inlet base cylinder 401 are selected, the heat conductivity is required to be strong, the heat conductivity coefficient is required to be more than 200w/(m multiplied by k), the heat conductivity coefficient of the materials is required to be not less than 100w/(m multiplied by k) under the high-temperature condition, namely the heating temperature of the bolt is 200-400 ℃, the high-heat-conductivity materials can accelerate the heat transfer, the heating time is further shortened, and the high-heat-conductivity materials can be made of copper and copper alloy. The material of the outer side part of the air inlet end of the air inlet basic cylinder 401 needs to have good heat insulation performance and small heat conductivity coefficient, the heat conductivity coefficient is lower than 10w/(m multiplied by k), and the air inlet basic cylinder can be made of aluminum silicate ceramic fiber special-shaped parts, so that the heat loss of an inlet flow guide section can be reduced, and the introduced gas can keep high temperature. The metal material of the outlet cylinder is selected according to the requirements of good heat insulation performance and small heat conductivity coefficient, the heat conductivity coefficient is lower than 10w/(m multiplied by k), and the outlet cylinder can be manufactured by aluminum silicate ceramic fiber special-shaped parts, so that the heat loss at the outlet can be reduced, and the integral heat utilization rate is higher.
In the embodiment of the present invention, the air inlet section 1 is a section of cylinder with a boss at the middle and outside, the length of the cylinder is greater than the length of the bolt, and it should be noted that the boss position needs to meet the position requirement of the component outlet sleeve 402; furthermore, taking the high-pressure cylinder bolt as an example, the length of the high-pressure cylinder bolt can reach 900 mm. The cylinder length of the air inlet section 1 should be about 1.1-1.2 times of the bolt length, and the length of the air inlet section 1 of the high-pressure cylinder body bolt is 990 mm-1080 mm. The boss structure should account for 0.03 ~ 0.05 times of the 1 length of section of admitting air in drum diameter direction, then should be about 30mm ~ 50mm to the width of the 1 boss structure of section of admitting air in the heating structure of high pressure cylinder body bolt, the boss structure of higher width is favorable to overall structure's gas tightness to and be favorable to and give vent to anger the cooperation of 5 structures of section. Sufficient length should be reserved with the 1 port of section of admitting air to the lug boss structure so that the hyperbaric tank with admit air the section of being connected of 1, its also should not overlength, and then reduce the calorific loss of the section of admitting air 1, the terminal surface distance that the section of admitting air 1 entry terminal surface that then the lug boss annular structure is close is about 0.05 times of the section of admitting air 1 length with the terminal surface distance of the section of admitting air 1. Taking the high-pressure cylinder bolt as an example, the end surface of the boss is about 50mm away from the end surface of the air inlet section 1.
The air supply mesh holes 2 are positioned at the connecting part of the rear end of the air inlet section 1 and the closed section 3, and can be through holes which are uniformly distributed along the circumferential direction and the axial direction of the cylinder, and the positive correlation between the number and the aperture size of the through holes and the size of the bolt needs to be noticed; illustratively, taking the high-pressure cylinder bolt as an example, the bore diameter of the high-pressure cylinder bolt can reach 21 mm. The diameter of the holes should be 0.2-0.3 times of the outer diameter of the bolt holes, the number of the holes should be 5-6, and the number of the layers should be 4-5. In the area of the air supply mesh 2, the open area should be approximately equal to the non-open area. More open area is favorable to the quick through of air current, can effectual increase heat transfer rate.
In the embodiment of the invention, the diameter of the outer wall of the air inlet section 1 and the thickness of the cylinder are related to the inner diameter of the bolt hole. In order to maintain heating and strength, the outer diameter should be about 0.15 times the inner diameter of the bolt hole away from the inner diameter of the bolt hole, i.e. the diameter of the outer wall of the cylinder 1 of the air inlet section is about 0.6 times the inner diameter of the bolt hole. Taking the high-pressure cylinder bolt as an example, the diameter of the high-pressure cylinder bolt can reach 21mm, and the outer diameter of the cylinder of the air inlet section 1 is about 12 mm. To maintain structural strength, the thickness of the barrel should be 1mm to 2 mm.
In the embodiment of the present invention, the closed section 3 is a closed cylindrical section disposed at the bottom of the air inlet section 1, and it should be noted that the length of the closed cylindrical section should meet the size requirement of the bolt section to be heated. The closing section 3 serves to support the stable structure, so that the length should not be too short, but an excessively long closing section 3 affects the rate of temperature rise of the corresponding bolt section. Therefore, the dimension of the closed section 3 in the present invention should be about 0.1 to 0.2 times the length of the bolt. Taking a high-pressure cylinder bolt as an example, the length of the bolt is 900mm, and the size of the closed section 3 is 90-180 mm. The difference between the outer diameter of the closed section 3 and the inner diameter of the bolt is about 0.2mm, so that the assembly and the disassembly after cooling are convenient. When the bolt works, the closed section 3 expands due to the heating of the airflow, and is tightly attached to the inner wall of the bolt; when the device is taken out after heating is finished, the expansion rate is different after cooling due to the difference of materials and bolts, and the device can be quickly separated from the bolts.
In the embodiment of the invention, the outlet rectifying section 4 is specifically a cylinder which can be sleeved on the air inlet section 1, and a port can be matched with a boss of the air inlet section 1 for positioning and sealing, and attention needs to be paid to that the outer surface of the cylinder is tightly matched with the inner surface of a stud in a cooling state of the cylinder; the air outlet section 5 is a cylinder which is vertical to the rectifying section and is communicated with the rectifying section. The whole length of the outlet sleeve 402 is 0.2 times of the length of the bolt, the diameter of the outer wall of the outlet sleeve is the inner bore diameter of the bolt, and the thickness of the outlet sleeve is 1 mm-2 mm. The inner wall diameter of the cooperation department of outlet sleeve 402 and the section of admitting air 1 protrusion annular structure is the same with the outer wall diameter of the section of admitting air 1, realizes promptly that the sleeve of giving vent to anger closely cooperates with the section of admitting air 1, reduces revealing of high-temperature gas. The length of the 5-port of the air outlet section is 0.05 time of the length of the bolt, the inner diameter of the air outlet section is 0.8 time of the inner diameter of the air inlet section 1, and the thickness of the air outlet section is the same as the integral thickness of the air outlet sleeve. Taking a high-pressure cylinder bolt as an example, the length of the bolt is 900mm, the aperture of the bolt can reach 21mm, the diameter of the outer wall of the outlet sleeve 402 is 21mm, the length of the 5-port part of the air outlet section is about 45mm, and the inner diameter is about 9 mm.
Referring to fig. 6, a method for using a convection heating device 400 for hot tightening of a split bolt in a cylinder according to an embodiment of the present invention includes the following steps:
the high-temperature gas can flow into the gas inlet base cylinder 401 with the convection heating pipe structure under the driving of high pressure, and the part of the gas inlet section 1 leaking out of the bolt is made of heat insulation materials, so that the gas temperature is hardly reduced. And because the air inlet basic cylinder 401 is of a straight cylinder structure, air flow in the air inlet basic cylinder 401 can rapidly pass through, and at the moment, high-temperature air flow carries out convective heat transfer on the cylinder wall of the air inlet section 1 of the air inlet basic cylinder 401, so that the cylinder wall of the air inlet section 1 is maintained at a higher temperature (almost the same as the air flow temperature).
Secondly, the high temperature air flow flows into the end of the air inlet basic cylinder 401 composed of the air feeding mesh 2 and the bottom closed section 3, and the air flow flows into the flowing area composed of the outer wall of the air inlet section 1 and the inner wall of the bolt from the air feeding mesh 2. The bottom closed section 3 is heated by the heat exchange of high-temperature airflow, expands to contact with the inner wall of the bolt, and then conducts contact heat transfer to the rear end of the bolt. And then, high-temperature airflow enters a flowing area formed by the outer wall of the air inlet section 1 and the inner wall of the bolt, the airflow directly carries out heat convection with the inner wall of the bolt, and the bolt is heated to a preheating temperature (200-400 ℃). The outer wall of the air inlet section 1 is kept at a higher temperature due to the heat transfer influence of the inner wall, so that the outer wall also carries out heat convection on the air flow, the temperature of the air in the whole flowing area is kept at a higher level, and the temperature of the air at the tail end of the heating cannot be reduced to a temperature which cannot meet the heating requirement.
Finally, the gas flows through a flow area formed by the outer wall of the gas inlet section 1 and the inner wall of the bolt, enters the outlet sleeve 402 structure, and flows out of the structure to a low-pressure pipe from the gas outlet section 5. The outlet sleeve 402 is a thermally insulating material, reducing the heat loss of the gas. The gas driving force of the whole device is the pressure difference of the gas in the high-pressure tank and the low-pressure pipe.
In fig. 6, the hatched surface is the bearing surface on the cylinder, corresponding to the fastening surface of the connecting wedge. In the operation process, the port of the air inlet section is connected with an air compressing tank capable of adjusting the flow of air flow, high-temperature air flow enters the cylinder from the port of the air inlet section after the proper flow is adjusted, flows into the air inlet section linearly and rapidly, flows into the flow channels on the inner sides of the air inlet basic cylinder and the bolts through the through holes, and is collected to the air outlet section through the rectifying section to flow out of the structure.
The illustrative optional, installation steam turbine and gas turbine cylinder bolt put into the middle of the double-screw bolt and the adjustment position with the basic section of thick bamboo of admitting air of bolt convection heating pipe, directly put the cover on the basic section of thick bamboo of admitting air with the export sleeve of bolt convection heating pipe, guarantee the laminating of two section of thick bamboo draw-in groove positions. And connecting the high-temperature air pressing tank to the air inlet port and connecting the air outlet port to the recovery tank. After the installation of inspection sleeve and gas pitcher, open high temperature pressure gas pitcher for less flow for bolt convection heating pipe structure is heated the inflation, makes between the heating pipe structure substructure, is connected more closely between heating pipe and the bolt. The high-temperature gas tank is adjusted to be working flow, high-temperature gas flows through a flow channel between the heating pipe and the bolt quickly, the bolt and the gas flow have large heat exchange due to quick passing of the high-temperature gas flow, the bolt is heated up quickly, and the pre-tightening force requirement is met. Compared with the traditional resistance heating rod, the heat pipe in the invention has simple structure, only two sleeves need to be installed, and the assembly and disassembly are convenient; more electrical equipment matched with a resistance heating rod is not needed, and only a high-temperature pressure gas tank and a recovery tank are needed; according to the invention, the stud is heated by adopting rapid high-temperature airflow, so that the heating temperature of each section is basically consistent, and the whole stud is uniformly heated; referring to fig. 7, it can be seen from the numerical simulation result that, during the heating process, the radial temperature difference of the bolt is substantially not different except at the inlet, and the temperature distribution is relatively uniform. The axial temperature changes smoothly in the heating process, the maximum temperature difference is only 30 ℃, and the thermal stress is small. In addition, in the heating process, the highest temperature in the bolt is never higher than the temperature of the air flow, so that the situation that local high temperature causes local yielding of materials in the bolt can be avoided.
The heat pipe structure can be simultaneously connected with a plurality of high-temperature pressure air tanks, so that the heating time of the whole air cylinder bolt is reduced, and more equipment is not required to be matched like a resistance heating rod. Taking a high-pressure cylinder as an example, the method performs numerical simulation calculation, and the model part adopted by the calculation is considered as the solid area of the bolt body of the contact part of the flow area formed by the inner wall of the bolt and the outer wall of the air inlet section and the air flow. The bolt size is: the outer diameter is 160 mm; the inner diameter is 21 mm; the length is 900 mm; considering the heating of the inner side of the air inlet section to the airflow on the outer wall of the air inlet section, the flowing boundary of the outer wall of the air inlet section is set to be an isothermal boundary condition and is equal to the temperature of the airflow at the inlet; the inner wall of the bolt and the flow area are set to be in a convection heat exchange condition; the temperature of the air flow at the inlet is slightly higher than the temperature of the bolt to be preheated; by adopting unsteady cfx calculation, the heating time of the high-pressure cylinder bolt is about 8-9 hours, and the temperature distribution in the heating process is shown in fig. 7.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (10)
1. A convection heating apparatus for hot-up of split bolt in a cylinder, comprising:
the air inlet base cylinder (401), one end of the air inlet base cylinder (401) is provided with an air inlet, and the other end of the air inlet base cylinder is a closed end; a plurality of air outlet through holes are formed in the preset part, close to the closed end, of the air inlet basic cylinder (401); a first flow channel is arranged in the air inlet basic cylinder (401);
an outlet sleeve (402), the outlet sleeve (402) being provided with an inlet and an outlet;
the gas inlet of the gas inlet basic cylinder (401) is used for introducing gas at a first preset temperature; the air inlet basic cylinder (401) is used for being installed in a column core of a bolt to be heated and tightened, an air inlet of the air inlet basic cylinder (401) is arranged outside the column core of the bolt to be heated and tightened, and a second flow channel is formed by the outer wall surface of the air inlet basic cylinder (401) and the inner wall surface of the column core of the bolt to be heated and tightened; the outlet sleeve (402) is sleeved outside an air inlet of the air inlet basic cylinder (401) and used for plugging an outlet of a column core of the bolt to be thermally tightened;
the air inlet is communicated with the outlet of the outlet sleeve (402) through the inlets of the first flow channel, the plurality of air outlet through holes, the second flow channel and the outlet sleeve (402) in sequence, and gas introduced into the second flow channel is used for heating the bolts to be thermally tightened to a second preset temperature to achieve thermal tightening.
2. The convective heating apparatus for split bolt hot-up in a cylinder of claim 1, wherein the gas is air;
the air inlet of the air inlet basic cylinder (401) is filled with air at the air flow rate of 5-7 m/s, and the air pressure is 1.5-2 times of atmospheric pressure.
3. The convection heating device for the hot-tightening of split bolts in a cylinder as set forth in claim 2, wherein the first preset temperature is 250-450 ℃.
4. The convection heating apparatus for split bolt hot-clinching in a cylinder as set forth in claim 3, wherein said second predetermined temperature is 200-400 ℃.
5. The convection heating device for split bolt hot-fastening in a cylinder according to claim 1, wherein the air intake base cylinder (401) is used for being installed in a column core of a bolt to be hot-fastened,
the closed end of the air inlet base cylinder (401) is used for being installed in a column core of a bolt to be hot-tightened in an inserting mode.
6. The convection heating device for split bolt hot-up in cylinder as set forth in claim 1, wherein the outer wall surface at the air inlet of the air intake base cylinder (401) is provided with an annular boss portion for fitting the outlet sleeve (402).
7. The convection heating device for split bolt tightening in cylinder according to claim 1, wherein a plurality of air outlet through holes are provided at predetermined positions of the air inlet basic cylinder (401) near the closed end,
the basic section of thick bamboo of admitting air (401) is close to set up on a plurality of predetermined cross-sections of blind end a plurality of air outlet holes, air outlet hole on every cross-section all along circumference equipartition.
8. The convection heating device for split bolt hot-up in a cylinder according to claim 1, wherein the air intake base cylinder (401) is of a straight cylinder structure;
the air inlet parts of the outlet sleeve (402) and the air inlet basic cylinder (401) are made of heat insulating materials.
9. The convection heating system for split bolt hot-clinching in a cylinder of claim 1, including a plurality of the convection heating apparatuses of claim 1;
the convection heating devices adopt the same air source and are used for being simultaneously and respectively inserted into a plurality of bolts to be heated and tightened of the middle section of the cylinder.
10. A method of using the convective heating arrangement for split bolt hot-up in a cylinder of claim 1, comprising the steps of:
installing an air inlet basic cylinder (401) in a column core of a bolt to be heated and tightened, wherein an air inlet of the air inlet basic cylinder (401) is arranged outside the column core of the bolt to be heated and tightened, and a second flow channel is formed by the outer wall surface of the air inlet basic cylinder (401) and the inner wall surface of the column core of the bolt to be heated and tightened;
sleeving an outlet sleeve (402) outside an air inlet of the air inlet basic cylinder (401) to plug an outlet of a column core of the bolt to be thermally tightened;
the gas inlet through basic section of thick bamboo (401) of admitting air lets in the gas of first preset temperature, and gas gets into the second runner through first runner and outlet vent hole, and the gas heating that gets into the second runner treat that hot tight bolt is to the second temperature of predetermineeing realizes hot tight, leads to the gas after the heat transfer through the export of export sleeve (402).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210386090.7A CN114700681A (en) | 2022-04-13 | 2022-04-13 | Convection heating device for hot tightening of split bolt in cylinder and use method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210386090.7A CN114700681A (en) | 2022-04-13 | 2022-04-13 | Convection heating device for hot tightening of split bolt in cylinder and use method thereof |
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| CN114700681A true CN114700681A (en) | 2022-07-05 |
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| CN202210386090.7A Pending CN114700681A (en) | 2022-04-13 | 2022-04-13 | Convection heating device for hot tightening of split bolt in cylinder and use method thereof |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87106713A (en) * | 1986-10-01 | 1988-04-13 | 东芝株式会社 | The method of adjustment of quick-connecting bolt and fastening force thereof |
| CA2313501A1 (en) * | 2000-04-12 | 2001-10-12 | George Tatarczuk | Gas bolt heater |
| CN201159461Y (en) * | 2007-12-14 | 2008-12-03 | 上海电气电站设备有限公司 | Flame heater for cylinder coupling bolt of turbine |
| CN101718470A (en) * | 2008-10-09 | 2010-06-02 | 扬中市华能电力设备有限公司 | Portable gas bolt heating device |
| CN103180088A (en) * | 2011-10-26 | 2013-06-26 | Newpol机械工程有限公司 | Gas bolt heating apparatus |
| CN205610961U (en) * | 2016-05-17 | 2016-09-28 | 青岛海越机电科技有限公司 | Steam turbine cylinder induction heater |
| CN111970776A (en) * | 2020-09-29 | 2020-11-20 | 核电运行研究(上海)有限公司 | High-frequency induction heating device for through hole hot-tightening bolt of steam turbine |
| CN112658591A (en) * | 2020-12-01 | 2021-04-16 | 山东齐鲁电机制造有限公司 | Heating device and method for hot tightening of large bolts of steam turbine |
| CN113909800A (en) * | 2021-10-18 | 2022-01-11 | 中核核电运行管理有限公司 | Resistance heating control device and method for hot-fastening bolt |
-
2022
- 2022-04-13 CN CN202210386090.7A patent/CN114700681A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87106713A (en) * | 1986-10-01 | 1988-04-13 | 东芝株式会社 | The method of adjustment of quick-connecting bolt and fastening force thereof |
| CA2313501A1 (en) * | 2000-04-12 | 2001-10-12 | George Tatarczuk | Gas bolt heater |
| CN201159461Y (en) * | 2007-12-14 | 2008-12-03 | 上海电气电站设备有限公司 | Flame heater for cylinder coupling bolt of turbine |
| CN101718470A (en) * | 2008-10-09 | 2010-06-02 | 扬中市华能电力设备有限公司 | Portable gas bolt heating device |
| CN103180088A (en) * | 2011-10-26 | 2013-06-26 | Newpol机械工程有限公司 | Gas bolt heating apparatus |
| CN205610961U (en) * | 2016-05-17 | 2016-09-28 | 青岛海越机电科技有限公司 | Steam turbine cylinder induction heater |
| CN111970776A (en) * | 2020-09-29 | 2020-11-20 | 核电运行研究(上海)有限公司 | High-frequency induction heating device for through hole hot-tightening bolt of steam turbine |
| CN112658591A (en) * | 2020-12-01 | 2021-04-16 | 山东齐鲁电机制造有限公司 | Heating device and method for hot tightening of large bolts of steam turbine |
| CN113909800A (en) * | 2021-10-18 | 2022-01-11 | 中核核电运行管理有限公司 | Resistance heating control device and method for hot-fastening bolt |
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