CN112489968A - Large-volume dry type direct current casing core curing control method - Google Patents
Large-volume dry type direct current casing core curing control method Download PDFInfo
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- CN112489968A CN112489968A CN201910862521.0A CN201910862521A CN112489968A CN 112489968 A CN112489968 A CN 112489968A CN 201910862521 A CN201910862521 A CN 201910862521A CN 112489968 A CN112489968 A CN 112489968A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B19/00—Apparatus or processes specially adapted for manufacturing insulators or insulating bodies
- H01B19/02—Drying; Impregnating
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
- H01F41/12—Insulating of windings
- H01F41/125—Other insulating structures; Insulating between coil and core, between different winding sections, around the coil
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Casting Or Compression Moulding Of Plastics Or The Like (AREA)
Abstract
The invention discloses a large-volume dry-type direct current sleeve core curing control method, which takes heat conducting oil as a heating medium to promote the reaction of epoxy resin and a curing agent; installing a temperature sensor in the large-volume dry type direct current sleeve core conduit to monitor the exothermic peak of the epoxy resin reaction; the heating process adopts segmented gradual heating, and the gradient temperature rise process is gradually reduced from bottom to top; according to the exothermic peak temperature curve when the large-volume dry-type direct current casing core is heated, stopping heating the tank body when the exothermic peak of the reaction reaches the highest exothermic peak; when the exothermic peak temperature line is reduced and is coincident with the heating set temperature of the tank body, the heating device is started again to perform segmented gradual heating, and the post-curing process of the core is implemented; the glass-transition temperature Tg of the solidified core is not less than 130 ℃ and the solidified core is qualified. The invention monitors the reaction exothermic peak value of the main insulating core in the curing process and adjusts the temperature, thereby avoiding the problems of core aging and core brittleness increasing, improving the yield and reducing the production cost.
Description
Technical Field
The invention relates to a dry type direct current sleeve manufacturing technology, in particular to a large-volume dry type direct current sleeve core solidification control method.
Background
The valve side sleeve of the dry type direct current (epoxy resin impregnated paper capacitance type) converter transformer is a core component of the high-end converter transformer, bears the voltage extraction and current carrying of the valve side, is used as the ground alternating current and direct current insulation and mechanical support of a conductive part, and is mainly applied to high-end direct current transmission engineering.
China is a major building country of direct current transmission engineering, the development technology of direct current bushings represents the most advanced technology in the field of transformer bushings, few bushing enterprises in China are gradually increased in the aspect of direct current bushing development investment, but after a prototype is successfully developed, the market popularization chance is less, and batch supply is not formed. The development phase is still being explored.
A main insulation capacitor core of a high-end dry type direct current (epoxy resin impregnated paper capacitance type) converter transformer valve side sleeve adopts an epoxy resin impregnated paper structure, the capacitor core is formed by rolling crepe paper and an aluminum foil electrode and impregnating and curing the crepe paper and the aluminum foil electrode by using epoxy resin, and the main insulation capacitor core is large in size and large in product manufacturing difficulty, so that three manufacturing difficulties, namely pouring control, curing control and machining control, are generally recognized in the manufacturing of the main insulation core.
At present, the curing control of the main insulating core in the manufacturing process adopts a production process of heating in place in one step, and the main insulating core is still heated when the peak value reaches the maximum value, so that the internal temperature of the core is overhigh, the core is easy to age, the brittleness of the core is increased, the core is easy to crack, the yield is reduced, and the production cost is increased.
Disclosure of Invention
Aiming at the defects that the solidification control of a main insulation core in the manufacturing process in the prior art is easy to cause core aging, core brittleness increasing and cracking and the like, the invention aims to solve the problem of providing a large-volume dry type direct current sleeve core solidification control method which can avoid core aging and core brittleness increasing by monitoring the reaction exothermic peak value to adjust the temperature.
In order to solve the technical problems, the invention adopts the technical scheme that:
the invention relates to a curing control method for a large-volume dry-type direct current sleeve core, which is characterized in that the large-volume dry-type direct current sleeve core is placed in a vacuum drying tank, and after the pouring is finished, the tank body is heated, and the curing control method comprises the following steps:
the heat conducting oil is used as a heating medium to promote the reaction of the epoxy resin and the curing agent;
installing a temperature sensor in the large-volume dry type direct current sleeve core conduit to monitor the exothermic peak of the epoxy resin reaction;
the heating process adopts segmented gradual heating, and the gradient temperature rise process is gradually reduced from bottom to top;
according to the exothermic peak temperature curve when the large-volume dry-type direct current casing core is heated, stopping heating the tank body when the exothermic peak of the reaction reaches the highest exothermic peak;
when the exothermic peak temperature line is reduced and is coincident with the heating set temperature of the tank body, the heating device is started again to perform segmented gradual heating, and the post-curing process of the core is implemented;
the glass-transition temperature Tg of the solidified core is not less than 130 ℃, and the solidified core is qualified.
The step-by-step heating in the subareas is as follows:
the large-volume dry-type direct current sleeve core is taken as a heating area from bottom to top at each specified distance, the temperature value of each heating area is gradually increased, and the temperature increase gradient is set to be 5 ℃.
The highest exothermic peak is: during curing reaction, the core of the casing releases a great deal of heat energy to make the temperature inside the core higher than the temperature of the tank, and when the temperature begins to drop, the inflection point of the temperature curve is the highest exothermic peak.
The large-volume dry-type direct-current casing core is formed by rolling crepe paper and an aluminum foil electrode, and the diameter of the main insulation is more than or equal to 600 mm; the length is more than or equal to 10000 mm.
The vacuum drying is provided with independent control of temperature of each zone during sectional and zone heating.
The invention has the following beneficial effects and advantages:
1. the invention monitors the reaction exothermic peak value of the main insulating core in the curing process and adjusts the temperature, thereby avoiding the problems of core aging and core brittleness increasing, improving the yield and reducing the production cost.
Drawings
FIG. 1 is a schematic diagram of a large-volume dry-type DC bushing core structure and a heating zone according to the present invention.
Wherein, 1 is a large-volume drying core, 2 is a temperature sensor, 3 is a first heating zone, 4 is a second heating zone, 5 is a third heating zone, 6 is a fourth heating zone, and 7 is a fifth heating zone.
Detailed Description
The invention is further elucidated with reference to the accompanying drawings.
The curing process of the large-volume dry type direct current casing core is an irreversible key control procedure in the manufacturing process of a high-end dry type direct current casing core used in the field of power transmission and transformation, namely a curing control process after the dry type core is poured, in particular to a solid production control process formed by fully drying corrugated insulating paper, pouring the paper by using liquid epoxy resin in a vacuum state, and heating the liquid resin after pouring to promote the resin to react with a curing agent.
The large-volume dry-type direct-current sleeve capacitor core is formed by rolling crepe paper and aluminum foil electrodes, then is placed into a metal mold and is vertically placed into a vertical vacuum drying tank, the core is fully dried and then poured, after the pouring is finished, the tank body is heated and heated, so that epoxy resin and a curing agent in the core are fully reacted, and a completely solid epoxy resin dry-type core is formed,
the invention mainly refers to a curing control process that the reaction of epoxy resin and curing agent is promoted by controlling the heating of a tank body after core pouring, the reaction heat release is controlled, and the relatively high glass transition temperature Tg is more than or equal to 130 ℃.
The invention relates to a curing control method for a large-volume dry-type direct current sleeve core, which is characterized in that the large-volume dry-type direct current sleeve core is placed in a vacuum drying tank, and after the pouring is finished, the tank body is heated, and the curing control method comprises the following steps:
the heat conducting oil is used as a heating medium to promote the reaction of the epoxy resin and the curing agent;
installing a temperature sensor in the large-volume dry type direct current sleeve core conduit to monitor the exothermic peak of the epoxy resin reaction;
the heating process adopts zone-by-zone gradual heating, and the gradient temperature rise process is gradually reduced from bottom to top;
according to the exothermic peak temperature curve when the large-volume dry-type direct current casing core is heated, stopping heating the tank body when the exothermic peak of the reaction reaches the highest exothermic peak;
when the exothermic peak temperature line is reduced and is coincident with the heating set temperature of the tank body, the heating device is started again to carry out segmented gradual heating, the temperature difference of 5 ℃ is still kept from bottom to top, and the post-curing process of the core is carried out;
the glass-transition temperature Tg of the solidified core is not less than 130 ℃, and the solidification is finished.
The step-by-step heating in different areas is as follows:
the large-volume dry-type direct current sleeve core is taken as a heating area from bottom to top at each specified distance, the temperature value of each heating area is gradually increased, and the temperature increase gradient is set to be 5 ℃.
The highest exothermic peak is: during curing reaction, the core of the casing releases a great deal of heat energy to make the temperature inside the core higher than the temperature of the tank, and when the temperature begins to drop, the inflection point of the temperature curve is the highest exothermic peak.
The large-volume dry-type direct-current casing core is formed by rolling crepe paper and an aluminum foil electrode, and the diameter of the main insulation is more than or equal to 600 mm; the length is more than or equal to 10000 mm.
The vacuum drying is provided with independent control of temperature of each zone during sectional and zone heating.
In the present example, the glass transition temperature Tg is the temperature at which the resin (liquid) changes from a high elastic state to a glassy state (solid). In fig. 1, one temperature sensor (in the present embodiment, a platinum resistor PT100) is seen for curing monitoring, and the other temperature sensors are installed in the tank heating layer in one-to-one correspondence with the heating zones of the large-volume dry-type dc bushing core, and the signal lines of all the temperature sensors are connected to a temperature controller.
As shown in fig. 1, the embodiment takes a large-volume dry-type dc bushing core with a diameter of 600mm and a length of 10000mm as an example, and is divided into five heating zones from bottom to top, i.e., first to fifth heating zones 3 to 7. The large-volume dry-type direct-current sleeve core is placed in a vacuum drying tank, after pouring (the pouring amount is more than or equal to 4000kg of epoxy resin and curing agent), the tank body is heated, the heating medium is heat conduction oil to promote the reaction of the epoxy resin and the curing agent, the heating process adopts segmented gradual heating, the gradient temperature rise process is gradually reduced from bottom to top, specifically, a heating area 1 is larger than a heating area 2 is larger than a heating area 3, a heating area 4 is larger than a heating area 5, and the gradient is set to be 5 DEG C
The PT100 platinum resistor is arranged in the core conduit and is mainly used for monitoring the exothermic peak of the epoxy resin reaction, and the tank body is stopped to be heated when the exothermic peak of the reaction reaches the highest point. And (3) as time goes on, the exothermic peak temperature line goes downwards and is coincident with the heating setting of the tank body, the next step of heating is started, and the post-curing process of the core is implemented. Other temperatures are simultaneously started and heated according to a set post-curing temperature curve, and the temperature difference is 5 ℃ from bottom to top.
After the core body is fully reacted and cured, sampling is carried out on the core body for testing, and when the glass transition temperature Tg is more than or equal to 130 ℃, the curing is qualified.
Claims (5)
1. A large-volume dry-type direct current sleeve core solidification control method is characterized by comprising the following steps of:
the heat conducting oil is used as a heating medium to promote the reaction of the epoxy resin and the curing agent;
installing a temperature sensor in the large-volume dry type direct current sleeve core conduit to monitor the exothermic peak of the epoxy resin reaction;
the heating process adopts segmented gradual heating, and the gradient temperature rise process is gradually reduced from bottom to top;
according to the exothermic peak temperature curve when the large-volume dry-type direct current casing core is heated, stopping heating the tank body when the exothermic peak of the reaction reaches the highest exothermic peak;
when the exothermic peak temperature line is reduced and is coincident with the heating set temperature of the tank body, the heating device is started again to perform segmented gradual heating, and the post-curing process of the core is implemented;
the glass-transition temperature Tg of the solidified core is not less than 130 ℃, and the solidified core is qualified.
2. The method for controlling the curing of the large-volume dry-type direct current bushing core according to claim 1, wherein the step-by-step heating in the sub-zones is:
the large-volume dry-type direct current sleeve core is taken as a heating area from bottom to top at each specified distance, the temperature value of each heating area is gradually increased, and the temperature increase gradient is set to be 5 ℃.
3. The method of claim 1, wherein the peak exothermic peak is: during curing reaction, the core of the casing releases a great deal of heat energy to make the temperature inside the core higher than the temperature of the tank, and when the temperature begins to drop, the inflection point of the temperature curve is the highest exothermic peak.
4. The method for controlling the curing of the large-volume dry-type direct current bushing core according to claim 1, wherein: the large-volume dry-type direct-current casing core is formed by rolling crepe paper and an aluminum foil electrode, and the diameter of the main insulation is more than or equal to 600 mm; the length is more than or equal to 10000 mm.
5. The method for controlling the curing of the large-volume dry-type direct current bushing core according to claim 1, wherein: the vacuum drying is provided with independent control of temperature of each zone during sectional and zone heating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910862521.0A CN112489968A (en) | 2019-09-12 | 2019-09-12 | Large-volume dry type direct current casing core curing control method |
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| CN201910862521.0A CN112489968A (en) | 2019-09-12 | 2019-09-12 | Large-volume dry type direct current casing core curing control method |
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| CN112489968A true CN112489968A (en) | 2021-03-12 |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011117893A2 (en) * | 2010-03-26 | 2011-09-29 | Crompton Greaves Limited | Method and heater for uniformly curing a resin impregnated electrical bushing |
| CN102286156A (en) * | 2011-01-19 | 2011-12-21 | 江苏宝亨新电气有限公司 | Large-capacity dry-type transformer curing process |
| CN104795254A (en) * | 2014-01-22 | 2015-07-22 | 特变电工沈阳变压器集团有限公司 | Ultrahigh-voltage oilpaper capacitive bushing capacitor core drying method |
| CN105070496A (en) * | 2015-07-24 | 2015-11-18 | 南京电气高压套管有限公司 | Glass fiber reinforced large-current transformer bushing and production method thereof |
| CN105633877A (en) * | 2015-12-28 | 2016-06-01 | 南京电气高压套管有限公司 | Dry capacitive-type through wall-penetrating bushing employing impregnated fiber |
| CN106486946A (en) * | 2016-12-26 | 2017-03-08 | 山东彼岸电力科技有限公司 | A kind of compound inslation immersion capacitive type wall bushing |
| CN108615589A (en) * | 2018-05-08 | 2018-10-02 | 安泽庆 | A kind of processing technology of dry type compound inslation bushing |
-
2019
- 2019-09-12 CN CN201910862521.0A patent/CN112489968A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011117893A2 (en) * | 2010-03-26 | 2011-09-29 | Crompton Greaves Limited | Method and heater for uniformly curing a resin impregnated electrical bushing |
| CN102286156A (en) * | 2011-01-19 | 2011-12-21 | 江苏宝亨新电气有限公司 | Large-capacity dry-type transformer curing process |
| CN104795254A (en) * | 2014-01-22 | 2015-07-22 | 特变电工沈阳变压器集团有限公司 | Ultrahigh-voltage oilpaper capacitive bushing capacitor core drying method |
| CN105070496A (en) * | 2015-07-24 | 2015-11-18 | 南京电气高压套管有限公司 | Glass fiber reinforced large-current transformer bushing and production method thereof |
| CN105633877A (en) * | 2015-12-28 | 2016-06-01 | 南京电气高压套管有限公司 | Dry capacitive-type through wall-penetrating bushing employing impregnated fiber |
| CN106486946A (en) * | 2016-12-26 | 2017-03-08 | 山东彼岸电力科技有限公司 | A kind of compound inslation immersion capacitive type wall bushing |
| CN108615589A (en) * | 2018-05-08 | 2018-10-02 | 安泽庆 | A kind of processing technology of dry type compound inslation bushing |
Non-Patent Citations (2)
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Application publication date: 20210312 |
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