CN114736036A

CN114736036A - Large-volume ultra-high-performance concrete thermal curing system and thermal curing process

Info

Publication number: CN114736036A
Application number: CN202210195256.7A
Authority: CN
Inventors: 李植; 吴新印; 万国强; 胡臻峰; 王森海
Original assignee: Hunan Zhonglu Huacheng Bridge Technology Co ltd; Guangdong Middle Road Protection Engineering Co ltd
Current assignee: Hunan Zhonglu Huacheng Bridge Technology Co ltd; Guangdong Middle Road Protection Engineering Co ltd
Priority date: 2022-03-01
Filing date: 2022-03-01
Publication date: 2022-07-12

Abstract

The invention discloses a large-volume ultra-high performance concrete thermal curing system and a thermal curing process, belonging to the technical field of bridges and related civil engineering, wherein an insulation shed is arranged on large-volume UHPC concrete and is surrounded on the periphery, a steam heating device is arranged on the ground around the large-volume UHPC concrete in the insulation shed, and a temperature adjusting device is arranged at the bottom of the large-volume UHPC concrete; the system provides a solution for uniformly heating and cooling the large-volume UHPC concrete in a front-back, upper-down, left-right omnibearing controllable temperature difference mode, and can intelligently realize that the temperature difference between a core part and the surface is stabilized between 5 and 15 degrees in the stages of maintenance heating and cooling, thereby greatly reducing the cracking risk of the large-volume UHPC concrete structure and improving the engineering quality; meanwhile, because the absolute temperature rise of a large UHPC concrete structure is large, the traditional cooling time is long, the system can rapidly cool by adopting gradient constant-temperature water and can ensure that the temperature difference of the inner surface is within a controllable set value. The construction period is shortened, and the comprehensive cost of the project is effectively reduced.

Description

Large-volume ultrahigh-performance concrete thermal curing system and thermal curing process

Technical Field

The invention relates to the technical field of bridges and related civil engineering, in particular to a large-volume ultrahigh-performance concrete thermal curing system and a thermal curing process.

Background

The Ultra-high performance concrete is called UHPC (Ultra-high performance concrete) for short, the UHPC can be called as an engineering material with the best durability, the mechanical property of the UHPC with proper reinforcement is close to that of a steel structure, and meanwhile, the UHPC has excellent wear resistance and anti-explosion performance. Therefore, UHPC is particularly suitable for use in large span bridges, blast resistant structures (military engineering, bank vaults, etc.) and thin-walled structures, as well as in highly abrasive, highly corrosive environments. Currently, UHPC has been applied in some practical projects, such as large-span pedestrian bridges, highway and railway bridges, thin-walled silos, nuclear waste tanks, wire rope anchor stiffeners, ATM machine protective casings, and the like.

The large-volume concrete construction mainly adopts natural curing at present, and the surface temperature difference is controlled by heat preservation measures, and cooling water pipes are pre-buried in a concrete structure, and natural water cooling is adopted, so that natural cooling or top water storage heat preservation is adopted for working conditions which are not suitable for pre-burying the cooling water pipes in the concrete structure. The cooling mode can not realize synchronous temperature rise and temperature reduction, the actual application cases of the large-volume ultrahigh-performance concrete are few at present, the traditional large-volume common concrete curing process is basically adopted, and because the cement dosage of the large-volume ultrahigh-performance concrete is high, the absolute temperature rise of hydration heat is 2 times of that of the common concrete, when the absolute temperature of the large-volume ultrahigh-performance concrete is high, the extremely large internal and external temperature difference is inevitably generated, the risk of structural cracking is increased, meanwhile, the temperature reduction is slower, the construction period is longer, and the efficiency is low.

Disclosure of Invention

The invention aims to provide a large-volume ultrahigh-performance concrete thermal curing system and a thermal curing process, and solves the following technical problems: the existing novel material, namely large-volume ultra-high performance concrete (UHPC), is subjected to heat curing, the ultra-high performance concrete is a novel material with high strength and high durability, the hydration heat of the novel material is more than 2 times that of common concrete, the core temperature of the large-volume UHPC concrete is as high as 90 degrees (or higher), the surface temperature difference is extremely large, and the problem of risk of cracking of a large-volume structure is caused to increase steeply and the like.

The purpose of the invention can be realized by the following technical scheme:

the invention discloses a large-volume ultra-high performance concrete thermal curing system, which comprises a thermal insulation shed, a heating adjusting device, large-volume UHPC concrete, a constant-temperature water cooling device and a process intelligent control device, wherein the constant-temperature water cooling device is connected with the thermal insulation shed; the heat preservation shed is arranged above the large-volume UHPC concrete and surrounds the large-volume UHPC concrete, and the heat preservation shed is used for preserving heat of the large-volume UHPC concrete; temperature rise adjusting devices are distributed on the periphery, the top surface and the bottom surface of the large-volume UHPC concrete, and the temperature rise adjusting devices are used for synchronously raising the temperature of the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface, the top surface and the bottom surface of the large-volume UHPC concrete; constant-temperature water cooling devices are distributed in all directions on the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete, and are used for synchronously reducing the uniform cooling temperature of the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete; constant-temperature water bottom heating and cooling heat exchange tubes are distributed in the base of the large-volume UHPC concrete, and the bottom heating and cooling heat exchange tubes are used for uniformly heating and synchronously heating the bottom of the large-volume UHPC concrete when the temperature is raised, and synchronously reducing the uniform cooling temperature when the temperature is lowered; the process intelligent control device is arranged at the periphery of the large-volume UHPC concrete, temperature sensors of the process intelligent control device are arranged at the large-volume UHPC concrete core part, the surface layer, the inner cavity of the thermal insulation shed and the constant-temperature hot water source and used for detecting the real-time temperatures of the core part, the surface layer, the inner cavity of the thermal insulation shed and the hot water source, and when the temperature rises, the process intelligent control device automatically sends out an instruction and controls related valve elements to open so that the temperature rise adjusting device starts to convey heat, and the uniform controllable rate temperature rise of the large-volume UHPC concrete core part and the surface layer is realized; when the temperature is reduced, the intelligent process control device automatically sends an instruction and controls -related valve elements to enable the constant-temperature water cooling device to convey constant-temperature water with the temperature lower than the temperature of the core part and to circularly flow, heat exchange is carried out by utilizing the temperature difference, the heat of the large-volume UHPC concrete is quickly taken away, and uniform and controllable speed cooling is realized; the structure and the function form a large-size ultrahigh-performance concrete thermal curing system.

As a further scheme of the invention: the constant-temperature water cooling device comprises an intelligent-regulation constant-temperature hot water source, a constant-temperature hot water pump, a tee joint, a bottom heating and cooling heat exchange pipe, a constant-temperature water automatic control valve I, a flow rate regulating valve I and a parallel header pipe, one side of the intelligent regulation constant-temperature hot water source is connected with a constant-temperature hot water pump through a pipeline, the other end of the constant-temperature hot water pump is connected with a tee joint, one outlet of the tee joint is connected with a parallel main pipe of the bottom heating and cooling heat exchange pipe, a first constant-temperature water automatic control valve and a first flow control valve are distributed on the parallel main pipe of the bottom heating and cooling heat exchange pipe, a plurality of bottom heating and cooling heat exchange tubes are arranged in the base side by side, the large part of the heat exchange tubes in the length direction is buried below the upper plane of the base by 0-30 cm, one end of each heat exchange tube is connected with a parallel header pipe arranged on the ground of the base, and the other end of each heat exchange tube is bent to extend out of the upper plane of the base to discharge circulating constant-temperature cooling water.

As a further scheme of the invention: the bottom heating and cooling heat exchange tubes are square flat tubes, and the distance between every two bottom heating and cooling heat exchange tubes is 5-30 cm.

As a further scheme of the invention: the constant-temperature water cooling device also comprises a main pipe, an upper plane water delivery pipe, a constant-temperature water automatic control valve II, a flow regulating valve II, a vertical surface constant-temperature water cooling pipe, a constant-temperature water automatic control valve III and a flow regulating valve III;

one other outlet of the tee joint is connected with a main pipe, an upper plane water pipe and a vertical surface constant temperature water cooling pipe are sequentially arranged on the main pipe, a constant temperature water automatic control valve II and a flow control valve II are arranged on the upper plane water pipe, and the upper plane water pipe is used for cooling water conveyed in a large-volume UHPC concrete upper plane water storage area;

the vertical surface constant temperature water cooling pipe is provided with a third constant temperature water automatic control valve and a third flow control valve, the vertical surface constant temperature water cooling pipe is arranged above the edge of the vertical surface around the large-volume UHPC concrete, water outlet holes are uniformly formed in the bottom of the vertical surface constant temperature water cooling pipe, and the vertical surface constant temperature water cooling pipe is used for spraying constant temperature water to the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface of the large-volume UHPC concrete for cooling.

As a further scheme of the invention: the temperature rise adjusting device comprises a steam generating device, an automatic control steam valve, a uniform steam conveying pipe, steam distributing holes, an intelligent adjusting constant temperature hot water source, a constant temperature hot water pump, a tee joint, a bottom heating pipe, a cooling heat exchange pipe, a first constant temperature water automatic control valve, a first flow regulating valve and a parallel header pipe, wherein the steam generating device is arranged on the periphery outside the large-volume UHPC concrete, a steam output pipe of the steam generating device is communicated with the uniform steam conveying pipe, the uniform steam conveying pipe is arranged on the lower bottom surface of the periphery of the outer side of the large-volume UHPC concrete, the automatic control steam valve is arranged at the input end of the uniform steam conveying pipe, a plurality of 0.2-3mm steam distributing holes are uniformly arranged on the uniform steam conveying pipe in the direction close to the side of the heat preservation shed, and automatic control steam distributing holes are opened when the difference between the core temperature and the surface layer temperature detected by the intelligent process control device reaches a set value, steam of the steam generating device is conveyed into the heat preservation shed through the steam uniform conveying pipe and the steam distribution holes, the periphery and the top of the large-volume UHPC concrete absorb heat and rise in temperature, so that the temperature of a heat absorption part rises at a preset rate, and the temperature rises synchronously with the temperature rise of core hydration heat; meanwhile, the process intelligent control device sends an instruction to pump constant-temperature hot water of an intelligent-adjustment constant-temperature hot water source at a water temperature higher than the preset temperature value of the core part by a constant-temperature hot water pump, after a first constant-temperature water automatic control valve and a first flow control valve are opened , the constant-temperature hot water higher than the preset temperature value of the core part enters the inlet end of a bottom heating and cooling heat exchange tube, then the constant-temperature hot water flows out from the other end at a certain preset flow rate and enters a warm water recycling enclosure, the temperature of the constant-temperature hot water in the bottom heating and cooling heat exchange tube is higher than or equal to the temperature of the core part, and the heat of the constant-temperature hot water is transmitted to the bottom of the large-volume UHPC concrete, so that the temperature of the UHPC concrete rises at a preset rate and is synchronous with the temperature rise of hydration heat of the core part.

As a further scheme of the invention: the method is characterized in that warm water recycling devices are arranged around the large-size UHPC concrete, each warm water recycling device comprises a warm water recycling enclosure, a drain pipe, a warm water recycling pool, a warm water circulating water suction pipe and a warm water circulating pump, the warm water recycling enclosure is arranged around the heat preservation shed, the drain pipe is installed on one side of the warm water recycling enclosure, the drain pipe discharges warm water in the warm water recycling enclosure to the warm water recycling pool, the warm water recycling pool is embedded into the base, the warm water circulating water suction pipe is arranged in the warm water recycling pool, the other end of the warm water circulating water suction pipe is communicated with the warm water circulating pump, the other end of the warm water circulating pump is communicated with a circulating recycling warm water input pipe, and the recycled warm water is input into a water pool of the intelligent regulation constant-temperature hot water source.

As a further scheme of the invention: the height of the warm water recycling enclosure is 0.5cm-25 cm.

As a further scheme of the invention: the heat preservation shed is a front, back, left, right and top closed space structure, the sealing structure is arranged on the periphery of the lower part of the heat preservation shed and the upper plane of the base, the heat preservation layer of the heat preservation shed is at least arranged more than two layers, the inner layer is a waterproof layer, and the outer layer is a heat preservation material layer.

As a further scheme of the invention: the intelligent process control device comprises a PLC (programmable logic controller), a preset automatic control program for the thermal curing process of the large-volume ultrahigh-performance concrete, a temperature sensor, a first flow control valve, a second flow control valve, a third flow control valve, a first automatic control valve, a second automatic control valve, a third automatic control valve and a fourth automatic control valve, wherein the temperature sensor is distributed in a large-volume UHPC (ultra high performance concrete) concrete core part, the front, the rear, the left and the right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete are respectively provided with the temperature sensor, the temperature sensor and the temperature sensor, the temperature sensor is distributed in the heat preservation shed, and the water storage area at the top of the large-volume UHPC concrete is provided with the temperature sensor, the intelligent regulation constant-temperature hot water source is internally provided with a temperature sensor, the first flow regulating valve, the second flow regulating valve, the third flow regulating valve, the first automatic control valve, the second automatic control valve, the third automatic control valve and the fourth automatic control valve are all in wired connection with a PLC (programmable logic controller) of the intelligent process control device, and under the control of a self-control program of the large-volume ultrahigh-performance concrete thermal curing process, the temperature of the large-volume UHPC concrete core temperature sensor, the surface temperature sensor, the temperature sensor and the temperature sensor are automatically detected; the temperature of a temperature sensor 78 in the heat-preservation shed and the temperature of a temperature sensor in a top water storage area are regulated, the temperature of the temperature sensor in the constant-temperature hot water source is regulated, the internal and external temperature difference of the large-volume UHPC concrete is automatically calculated, whether the internal and external temperature difference is a set value or not is judged, when the preset condition is reached in the temperature rise stage, opening instructions are automatically sent to a first automatic control valve, a second automatic control valve, a third automatic control valve and a fourth automatic control valve by a program, and a constant-temperature hot water pump and a steam generation device work to provide heat sources for the first automatic control valve, the second automatic control valve, the third automatic control valve and the fourth automatic control valve, so that the large-volume UHPC concrete is uniformly and stably heated in the controllable temperature difference; when the large-volume UHPC concrete reaches the temperature rise peak value and exceeds 80 ℃, the system automatically maintains the temperature of the large-volume UHPC concrete to be above 80 ℃ for 72 hours; automatically giving an instruction in the automatic control program of the thermal curing process of the mass ultrahigh-performance concrete: and closing the self-control steam valve and the steam generating device, reducing the constant-temperature water temperature of the intelligent-adjustment constant-temperature hot water source, and simultaneously commanding the constant-temperature water temperature of the intelligent-adjustment constant-temperature hot water source to be adjusted downwards to actually-measured temperature difference set values of the front, the rear, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete. And automatically opening the first constant-temperature water automatic control valve, the first flow control valve, the third constant-temperature water automatic control valve, the third flow control valve, the second constant-temperature water automatic control valve and the second flow control valve to supply constant-temperature water with the temperature 5-25 ℃ lower than the temperature of the core part to enable the constant-temperature water to reach a proper flow, uniformly cooling the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete at a controllable speed rate, gradually reducing the temperature of the core part of the large-volume UHPC concrete along with the time, synchronously reducing an intelligent-regulation constant-temperature hot water source along with the temperature, and continuously and circularly descending until the temperature of the core part of the large-volume UHPC concrete is reduced to be within 15 ℃ of the temperature difference of the atmospheric environment, so that the thermal curing of the large-volume UHPC concrete can be completed.

As a further scheme of the invention: the thermal curing process of the large-volume ultrahigh-performance concrete thermal curing system comprises the following steps of:

firstly, the following preliminary preparation construction is carried out:

constructing a base, and constructing and embedding bottom heating and cooling heat exchange tubes and accessories;

installing a large-volume UHPC concrete structural steel bar and accessories; installing a temperature sensor, a temperature sensor and a temperature sensor which are preset in the large-volume UHPC concrete, installing surrounding vertical face templates of the large-volume UHPC concrete, pouring the UHPC concrete, spraying water mist on the top surface of the UHPC concrete, and covering a moisture retention film;

after the preparation construction is finished, the following thermal curing process is carried out on the large-volume UHPC concrete:

the method comprises the following steps:

installing an intelligent regulating constant-temperature hot water source, a constant-temperature hot water pump, a tee joint, a bottom heating device, a constant-temperature water automatic control valve I, a flow control valve I, a parallel main pipe, a steam generating device, an automatic control steam valve, a steam uniform conveying pipe and a steam distribution hole around and above the large-volume UHPC concrete;

connecting and installing a control signal and action element connecting line between the process intelligent control device and the temperature measuring sensor and a host of the process intelligent control device;

installing and constructing a heat-preservation shed, and constructing a sealing structure between the periphery of the bottom of the heat-preservation shed and the base;

optional construction installation: the warm water recycling device comprises a warm water recycling enclosure, a drain pipe, a warm water recycling pool, a warm water circulating water suction pipe and a warm water circulating pump facility.

Step two:

the process intelligent control device host is internally provided with a self-control program for the large-volume ultra-high performance concrete thermal curing process, and the self-control elements, circuits and logic relations of the self-control elements, circuits and logic relations are comprehensively debugged to ensure that no error exists.

Step three:

opening intelligent control device for large-volume ultra-high performance concrete thermal curing process, automatically operating and detecting the core temperature, surface temperature, temperature in the heat preservation shed, cooling water temperature and water storage area temperature of large-volume UHPC concrete according to preset process parameters, and starting automatic watching;

step four: after the large-volume UHPC concrete is poured, the large-volume UHPC concrete generates hydration heat to cause the temperature to rise, and the temperature rise speed of a core part is far greater than that of the periphery, at the moment, a system automatically detects the temperature of the core part and the temperature of a surface layer according to a preset certain frequency, when the difference value is close to a preset allowable difference value, a process intelligent control device sends a starting working instruction to a steam generating device and an intelligent regulation constant-temperature hot water source to respectively prepare steam and constant-temperature hot water matched with a heating process, when the difference value between the temperature of the core part and the temperature of the surface layer reaches the preset allowable difference value, a large-volume ultrahigh-performance concrete thermal curing process automatic control program sends an instruction to open an automatic control steam valve, a constant-temperature water automatic control valve and a flow control valve, steam of the steam generating device sends a proper amount of steam to a thermal insulation shed through a steam uniform conveying pipe, and the steam heats an inner cavity of the thermal insulation shed and the large-volume UHPC concrete front part, The temperature of the rear, left, right, top and bottom surfaces is uniformly raised, the steam delivery volume is synchronously adjusted according to the temperature rise speed of the large-volume UHPC concrete core, and the constant temperature water temperature and supply flow of a constant temperature hot water source are intelligently adjusted, so that the uniform and synchronous temperature rise of the front, rear, left, right, top and bottom surfaces of the large-volume UHPC concrete and the core is realized, and the temperature difference between the inside and the surface layer of the large-volume UHPC concrete is stably controlled; with the increase of hydration heat in the large-volume UHPC concrete, the temperature continuously rises, the process intelligent control device continuously synchronously adjusts the steam delivery volume according to the temperature rise speed of the large-volume UHPC concrete core and intelligently adjusts the constant-temperature water temperature and supply flow of the constant-temperature hot water source, and the uniform and synchronous temperature rise of the front, the back, the left, the right, the top surface, the bottom surface and the core of the large-volume UHPC concrete is continuously realized until the temperature rises to the highest limit temperature.

Step five, when the large-volume UHPC concrete reaches the temperature rise peak value and exceeds 80 ℃, the temperature of the large-volume UHPC concrete is maintained to be above 80 ℃ for 72 hours, the process intelligent control device is automatically switched from the temperature rise stage to the temperature reduction stage, and a built-in self-control program of the large-volume ultrahigh-performance concrete thermal curing process sends an instruction: and closing the self-control steam valve and the steam generating device, and reducing the constant-temperature water temperature of the intelligent-regulation constant-temperature hot water source.

Step six:

21855and a constant-temperature cooling process; the self-control program of the thermal curing process of the large-volume ultrahigh-performance concrete instructs the intelligent adjustment of the temperature of the constant-temperature water of the constant-temperature hot water source to be adjusted to the set value of the actually measured temperature difference between the front, the back, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete. Simultaneously, automatically opening a first constant-temperature water automatic control valve, a first flow control valve, a third constant-temperature water automatic control valve, a third flow control valve, a second constant-temperature water automatic control valve and a second flow control valve, supplying constant-temperature water with the temperature 5-25 ℃ lower than the temperature of a core part to a heating and cooling heat exchange pipe, an upper plane water pipe and a vertical plane constant-temperature water cooling pipe to ensure that the constant-temperature water reaches proper flow, uniformly cooling the front vertical surface, the rear vertical surface, the left vertical surface, the right vertical surface, the top surface and the bottom surface of the large-volume UHPC concrete at a controllable speed, increasing the temperature of lower constant-temperature water through heat exchange between the constant-temperature water and the large-volume UHPC concrete, rapidly carrying away the heat of the large-volume UHPC concrete, and synchronously, orderly and uniformly reducing the external temperatures of 6 surfaces of the large-volume UHPC concrete in a continuous constant-temperature water circulation process;

step seven: along with the gradual reduction of the core temperature, the intelligent-adjustment constant-temperature hot water source is synchronously reduced, and the intelligent-adjustment constant-temperature hot water source is continuously circulated and circularly reduced until the temperature of the large-volume UHPC concrete core is reduced to be within 15 ℃ of the difference between the temperature of the large-volume UHPC concrete core and the temperature of the atmospheric environment, so that the large-volume UHPC concrete is subjected to thermal curing;

optional auxiliary processes:

when setting up the warm water recycle device, warm water recycle encloses the fender and collects the warm water to discharge into the warm water recovery pond through the drain pipe in, the warm water circulating pump absorbs water the water in the pipe with the warm water recovery pond through the warm water circulation and takes out recycle in the intelligent regulation constant temperature hot water source, in continuous circulation, the water economy resource reduces the energy consumption.

The invention has the beneficial effects that:

(1) according to the invention, by adopting a scheme that a heat preservation shed is adopted for covering and preserving heat, steam is sent out, and a bottom heating and cooling heat exchange pipe is arranged in a large-volume UHPC concrete structure bottom surface bearing platform and is close to the UHPC concrete surface, the function of accurately controlling the surface temperature difference of the large-volume UHPC concrete structure is achieved by detecting the temperature difference among the core part, the surface and the constant temperature water temperature and intelligently controlling the heating rate, 6 surfaces of the large-volume UHPC concrete can be rapidly and synchronously heated, so that the temperature difference between the core part and the surface of the large-volume UHPC concrete can be controlled within a controllable range, the internal stress is reduced, and the cracking is avoided;

(2) meanwhile, by arranging the vertical surface constant-temperature water cooling pipe and the upper plane constant-temperature water cooling pipe, under the synergistic cooperation effect of the bottom heating and cooling heat exchange pipes, the cooling in all directions of the front, the back, the left, the right, the upper and the lower of the large-volume UHPC concrete structure can be synchronously performed, so that the surface temperature in the large-volume UHPC concrete is controllable, and the actual temperature difference value is consistent;

(3) warm water recycling barriers are arranged on the base to collect cooling (or heating) constant-temperature circulating water, so that the process cost is reduced, and water resources are saved; the temperature of the constant-temperature hot water source is intelligently adjusted according to the temperature difference between the core temperature and the surface temperature detected by the system, so that the temperature of the constant-temperature hot water source dynamically accords with a constant temperature value set by an automatic control program, and the temperature of the warm water source can be reduced at intervals; according to the invention, different inner surface control temperature difference values and difference values between the surface of the UHPC concrete and the dynamic constant temperature water temperature can be set according to UHPC concretes with different volumes; the application range is wider, and the practicability is stronger;

(4) the invention provides a process method for thermal curing and dynamic stable control of the inside temperature difference of large-volume UHPC concrete; the molding efficiency and quality of the large-volume UHPC concrete are improved;

(5) under the condition of not damaging the structural strength, the invention quickly reduces the heat generated by the hydration heat of the large-volume UHPC concrete through a process method and a structure, and obviously shortens the construction period.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view of a thermal curing system for mass ultra-high performance concrete according to the present invention;

FIG. 2 is a schematic perspective view of the temperature rise regulating device of the present invention;

FIG. 3 is a schematic perspective view of the constant temperature water cooling apparatus of the present invention;

FIG. 4 is a schematic perspective view of the warm water recycling apparatus according to the present invention;

FIG. 5 is a schematic perspective view of the temperature sensor connection in the process control system of the present invention;

FIG. 6 is a schematic view showing the three-dimensional structure of the connection between the thermostatic water automatic control valve and the flow control valve in the process intelligent control device of the present invention.

In the figure: 1. a base; 2. a warm water recycling device; 21. warm water recycling fenders; 22. a drain pipe; 23. a warm water recovery tank; 24. a warm water circulating water suction pipe; 25. a warm water circulating pump; 3. a thermal insulation shed; 31. a sealing structure; 4. a temperature rise adjusting device; 41. a steam generating device; 42. a self-control steam valve; 43. a steam uniform delivery pipe; 44. a vapor distribution aperture; 5. bulk UHPC concrete; 51. a template; 6. a constant temperature water cooling device; 61. intelligently adjusting a constant-temperature hot water source; 62. a constant temperature hot water pump; 63. a tee joint; 64. bottom heating and cooling heat exchange tubes; 642. a first constant-temperature water automatic control valve; 643. a first flow regulating valve; 644. a main pipe is connected in parallel; 65. a header pipe; 661. an upper plane water delivery pipe; 662. a second constant-temperature water automatic control valve; 663. a flow regulating valve II; 671. a vertical face constant temperature water cooling pipe; 672. a third constant-temperature water automatic control valve; 673. a flow regulating valve III; 68. recycling the warm water input pipe; 7. a process intelligent control device; 70. a PLC; 71. a temperature sensor; 72. a temperature sensor; 73. a temperature sensor; 74. a temperature sensor; 75. a temperature sensor; 76. a temperature sensor; 77. a temperature sensor; 78. a temperature sensor; 79. a temperature sensor; 710. a temperature sensor; 711. a first flow regulating valve; 712. a flow regulating valve II; 713. a flow regulating valve III; 714. a first automatic control valve; 715. a second self-control valve; 716. a third self-control valve; 717. and a fourth self-control valve.

Detailed Description

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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-6, the large-volume ultra-high performance concrete thermal curing system of the present invention comprises a thermal insulation shed 3, a temperature-raising adjusting device 4, a large-volume UHPC concrete 5, a constant temperature water cooling device 6, and a process intelligent control device 7; the heat preservation shed 3 is arranged above the large-volume UHPC concrete 5 and surrounds the large-volume UHPC concrete 5, and the heat preservation shed 3 is used for preserving heat of the large-volume UHPC concrete 5; temperature rise adjusting devices 4 are distributed on the periphery, the top surface and the bottom surface of the large-volume UHPC concrete 5, and the temperature rise adjusting devices 4 are used for synchronously raising the temperature of the front vertical surface, the rear vertical surface, the left vertical surface, the right vertical surface, the top surface and the bottom surface of the large-volume UHPC concrete 5; constant-temperature water cooling devices 6 are distributed in all directions on the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete 5, and the constant-temperature water cooling devices 6 are used for synchronously reducing the uniform cooling temperature of the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete 5; a constant-temperature water bottom heating and cooling heat exchange pipe 64 is distributed in the base 1 of the large-volume UHPC concrete 5, and the bottom heating and cooling heat exchange pipe 64 is used for uniformly heating and synchronously heating the bottom of the large-volume UHPC concrete 5 when the temperature is raised and synchronously reducing the uniform cooling temperature when the temperature is lowered; the process intelligent control device 7 is arranged on the periphery of the large-volume UHPC concrete 5, temperature sensors of the process intelligent control device 7 are arranged at the core part, the surface layer, the inner cavity of the thermal insulation shed 3 and a constant-temperature hot water source of the large-volume UHPC concrete 5 and used for detecting the real-time temperatures of the core part, the surface layer, the inner cavity of the thermal insulation shed and the hot water source, when the temperature rises, the process intelligent control device 7 automatically sends out an instruction and controls related valve elements to open so that the temperature rise adjusting device 4 starts to convey heat, and uniform controllable rate temperature rise of the core part and the surface layer of the large-volume UHPC concrete 5 is realized; when the temperature is reduced, the intelligent process control device 7 automatically sends an instruction and controls -related valve elements to enable the constant-temperature water cooling device 6 to convey constant-temperature water with the temperature lower than the temperature of the core part and to flow circularly, heat exchange is carried out by utilizing the temperature difference, the heat of the large-volume UHPC concrete 5 is taken away quickly, and uniform and controllable speed cooling is realized; the structure and the function form a large-size ultrahigh-performance concrete thermal curing system.

The constant-temperature water cooling device 6 comprises an intelligent regulation constant-temperature hot water source 61, a constant-temperature hot water pump 62, a tee joint 63, a bottom heating and cooling heat exchange pipe 64, a constant-temperature water automatic control valve 642, a flow rate regulation valve 643 and a parallel main pipe 644, wherein one side of the intelligent regulation constant-temperature hot water source 61 is connected with the constant-temperature hot water pump 62 through a pipeline, the other end of the constant-temperature hot water pump 62 is connected with the tee joint 63, one outlet of the tee joint 63 is connected with the parallel main pipe 644 of the bottom heating and cooling heat exchange pipe 64, the parallel main pipe 644 of the bottom heating and cooling heat exchange pipe 64 is provided with the constant-temperature water automatic control valve 642 and the flow rate regulation valve 643, a plurality of bottom heating and cooling heat exchange pipes 64 are arranged in the base 1 side by side, the major part of the length direction of each heat exchange pipe is buried below the upper plane of the base by 15cm, and one end of each heat exchange pipe is connected with the parallel main pipe 644 arranged on the ground of the base 1, the other end is bent to extend out of the upper plane of the base 1, and circulating constant-temperature cooling water is discharged.

The bottom heating and cooling heat exchange tubes 64 are square flat tubes, and the distance between every two bottom heating and cooling heat exchange tubes 64 is 10cm, so that the bottom heating and cooling heat exchange tubes are heated more uniformly and have higher efficiency.

The constant-temperature water cooling device 6 further comprises a header pipe 65, an upper plane water conveying pipe 661, a second constant-temperature water automatic control valve 662, a second flow regulating valve 663, a vertical surface constant-temperature water cooling pipe 671, a third constant-temperature water automatic control valve 672 and a third flow regulating valve 673;

one other outlet of the tee joint 63 is connected with a main pipe 65, an upper plane water pipe 661 and a vertical surface constant temperature water cooling pipe 671 are sequentially arranged on the main pipe 65, a constant temperature water automatic control valve II 662 and a flow rate regulating valve II 663 are arranged on the upper plane water pipe 661, and the upper plane water pipe 661 is used for cooling water conveyed in a plane water storage area on the large-volume UHPC concrete 5;

the vertical surface constant temperature water cooling pipe 671 is provided with a third constant temperature water automatic control valve 672 and a third flow control valve 673, the vertical surface constant temperature water cooling pipe 671 is arranged around the upper part of the edge of the vertical surface at the periphery of the large-volume UHPC concrete 5, water outlet holes are uniformly formed in the bottom of the vertical surface constant temperature water cooling pipe 671, and the vertical surface constant temperature water cooling pipe 671 is used for spraying constant temperature water to the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface of the large-volume UHPC concrete 5 for cooling.

The temperature rise adjusting device 4 comprises a steam generating device 41, an automatic control steam valve 42, a steam uniform delivery pipe 43, a steam distribution hole 44, an intelligent adjustment constant temperature hot water source 61, a constant temperature hot water pump 62, a tee joint 63, a bottom heating and cooling heat exchange pipe 64, a constant temperature water automatic control valve 642, a flow rate adjusting valve 643 and a parallel main pipe 644, wherein the steam generating device 41 is arranged on the periphery outside the large-volume UHPC concrete 5, a steam output pipe of the steam generating device 41 is communicated with the steam uniform delivery pipe 43, the steam uniform delivery pipe 43 is arranged on the lower bottom surface of the periphery of the outer side of the large-volume UHPC concrete 5, the automatic control steam valve 42 is arranged at the input end of the steam uniform delivery pipe 43, the steam uniform delivery pipe 43 is uniformly provided with a plurality of 1mm steam distribution holes 44 in the direction close to the side of the heat preservation shed 3, and the automatic control steam valve 42 is opened when the difference between the core temperature and the surface layer temperature detected by the intelligent process control device 7 reaches a set value, steam of the steam generating device 41 is conveyed into the heat-insulating shed 3 through the steam uniform conveying pipe 43 and the steam distributing holes 44, the periphery and the top of the large-volume UHPC concrete 5 absorb heat and rise in temperature, so that the temperature of a heat absorption part rises at a preset rate, and the steam and the temperature rise of core hydration heat are synchronous; meanwhile, the process intelligent control device 7 sends an instruction to pump the constant-temperature hot water of the intelligent-adjustment constant-temperature hot water source 61 at a water temperature higher than the preset temperature of the core part by the constant-temperature hot water pump 62, after the constant-temperature water automatic control valve 642 and the flow control valve 643 are opened , the constant-temperature hot water higher than the preset temperature of the core part enters the inlet end of the bottom heating and cooling heat exchange tube 64, then the constant-temperature hot water flows out from the other end at a certain preset flow rate and enters the warm water recycling enclosure 21, the temperature of the constant-temperature hot water in the bottom heating and cooling heat exchange tube 64 is higher than or equal to the temperature of the core part, and the heat of the constant-temperature hot water is transferred to the bottom of the large-volume UHPC concrete 5, so that the temperature of the constant-temperature hot water rises at a preset rate and is synchronous with the temperature rise of the hydration core part.

The warm water recycling device 2 is arranged around the large-volume UHPC concrete 5, the warm water recycling device 2 comprises a warm water recycling enclosure 21, a drain pipe 22, a warm water recycling pool 23, a warm water recycling water suction pipe 24 and a warm water circulating pump 25, the warm water recycling enclosure 21 is arranged around the heat preservation shed 3, the drain pipe 22 is arranged on one side of the warm water recycling enclosure 21, the drain pipe 22 discharges warm water in the warm water recycling enclosure 21 into the warm water recycling pool 23, the warm water recycling pool 23 is embedded in the base 1, the warm water recycling water suction pipe 24 is arranged in the warm water recycling pool 23, the other end of the warm water recycling water suction pipe 24 is communicated with the warm water circulating pump 25, and the other end of the warm water circulating pump 25 is communicated with a recycling warm water input pipe 69 to input recycled warm water into a water pool of the intelligent regulation constant-temperature hot water source 61.

The height of warm water recycle rail 21 is 3 cm.

Thermal-insulation shed 3 is preceding, back, left and right and the airtight space structure in top, and its lower part sets up seal structure 31 with base 1 upper plane all around, through setting up seal structure 31, can play good heat preservation effect, and thermal-insulation shed 3 heat preservation sets up more than two-layer at least, and the inlayer is waterproof layer, outer insulation material layer, has good heat preservation effect, can raise the temperature fast.

The intelligent process control device 7 comprises a PLC70, a preset self-control program for the thermal curing process of the large-volume ultrahigh-performance concrete, a temperature sensor 71, a temperature sensor 72, a temperature sensor 73, a temperature sensor 74, a temperature sensor 75, a temperature sensor 76, a temperature sensor 77, a temperature sensor 78, a temperature sensor 79, a temperature sensor 710, a first flow control valve 711, a second flow control valve 712, a third flow control valve 713, a first self-control valve 714, a second self-control valve 715, a third self-control valve 716 and a fourth self-control valve 717, wherein the temperature sensor 71 is arranged in a core of the large-volume UHPC concrete 5, the temperature sensor 72, the temperature sensor 73, the temperature sensor 74, the temperature sensor 75, the temperature sensor 76 and the temperature sensor 77 are respectively arranged on the front vertical surface, the rear surface, the left vertical surface, the right vertical surface and the bottom surface of the large-volume UHPC concrete 5, the temperature sensor 78 is distributed in the heat preservation shed 3, the temperature sensor 79 is distributed in the water storage area at the top of the large-volume UHPC concrete 5, the temperature sensor 710 is distributed in the intelligent regulation constant-temperature hot water source 61, the temperature sensor 71, the temperature sensor 72, the temperature sensor 73, the temperature sensor 74, the temperature sensor 75, the temperature sensor 76, the temperature sensor 77, the temperature sensor 78, the temperature sensor 79, the temperature sensor 710, the flow regulating valve I711, the flow regulating valve II 712, the flow regulating valve III 713, the self-control valve I714, the self-control valve II 715, the self-control valve III 716 and the self-control valve IV 717 are all in wired connection with the PLC70 of the intelligent process control device 7, and the temperature of the core temperature sensor 71 of the large-volume UHPC concrete 5 is automatically detected under the control of the large-volume ultrahigh-performance concrete thermal curing process, Temperatures of the surface temperature sensor 72, the temperature sensor 73, the temperature sensor 74, the temperature sensor 75, the temperature sensor 76, and the temperature sensor 77; the temperature of a temperature sensor 78 in the heat-preservation shed 3 and the temperature of a top water storage area temperature sensor 79 are adjusted, the temperature of a temperature sensor 710 in the constant-temperature hot water source 61 is adjusted, the internal and external temperature difference of the large-volume UHPC concrete 5 is automatically calculated, whether the internal and external temperature difference is a set value or not is judged, when the temperature rise stage reaches a preset condition, opening instructions are automatically sent to a self-control valve I, a self-control valve II, a self-control valve III and a self-control valve IV by a program, the constant-temperature hot water pump 62 and the steam generating device 41 work to provide heat sources for the self-control valves, and the large-volume UHPC concrete 5 is uniformly and stably heated in the controllable temperature difference; when the large-volume UHPC concrete 5 reaches the temperature rise peak value and exceeds 80 ℃, the system automatically maintains the temperature of the large-volume UHPC concrete 5 to be above 80 ℃ for 72 hours; automatically giving an instruction in the automatic control program of the thermal curing process of the mass ultrahigh-performance concrete: and closing the self-control steam valve 42 and the steam generating device 41, reducing the temperature of the constant-temperature water of the intelligent-adjustment constant-temperature hot water source 61, and simultaneously, commanding the temperature of the constant-temperature water of the intelligent-adjustment constant-temperature hot water source 61 to be adjusted to the actually measured temperature difference set values of the front, the back, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete. And automatically opening the first constant-temperature water automatic control valve 642, the first flow rate regulating valve 643, the third constant-temperature water automatic control valve 672, the third flow rate regulating valve 673, the second constant-temperature water automatic control valve 662 and the second flow rate regulating valve 663 to supply constant-temperature water with the temperature lower than 10 ℃ of the core part so as to enable the constant-temperature water to reach a proper flow rate, uniformly and controllably cooling the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete 5 at a speed rate, gradually reducing the core part temperature of the large-volume UHPC concrete 5 along with the time, synchronously reducing the intelligent regulating constant-temperature hot water source 41 along with the temperature, and continuously and circularly reducing the temperature until the temperature of the large-volume UHPC concrete core part is reduced to be within 15 ℃ of the difference with the atmospheric environment temperature, and finishing the thermal curing of the large-volume UHPC concrete 5.

The thermal curing process of the large-volume ultrahigh-performance concrete thermal curing system comprises the following steps of:

firstly, the following preliminary preparation construction is carried out:

constructing a base 1, constructing and embedding a bottom heating and cooling heat exchange tube 64 and accessories;

installing a large-volume UHPC concrete 5 structural steel bar and accessories; installing a temperature sensor 71, a temperature sensor 72, a temperature sensor 73, a temperature sensor 74, a temperature sensor 75, a temperature sensor 76 and a temperature sensor 77 which are preset in the large-volume UHPC concrete 5, installing surrounding vertical face templates 51 of the large-volume UHPC concrete 5, pouring the UHPC concrete 5, spraying water mist on the top surface of the UHPC concrete, and covering a moisture retention film;

after the preparation construction is finished, the following thermal curing process is carried out on the large-volume UHPC concrete 5:

the method comprises the following steps:

an intelligent adjusting constant-temperature hot water source 61, a constant-temperature hot water pump 62, a tee joint 63, bottom heating, a constant-temperature water automatic control valve 642, a flow control valve 643, a parallel main pipe 644, a steam generating device 41, an automatic control steam valve 42, a steam uniform conveying pipe 43 and a steam distributing hole 44 are arranged around and above the large-volume UHPC concrete 5;

connecting and installing a control signal and action element connecting line between the process intelligent control device 7 and the temperature measuring sensor and a host of the process intelligent control device 7;

the thermal insulation shed 3 is installed and built, and the sealing structure 31 is arranged between the periphery of the bottom of the thermal insulation shed and the base 1.

The system aims at the thermal curing of novel material large-volume ultrahigh-performance concrete (UHPC), the UHPC is a novel material with high strength and high durability, the hydration heat of the UHPC is more than 2 times that of common concrete, the core temperature of the large-volume UHPC concrete is as high as 90 degrees (or higher), the temperature difference between the inner surface and the outer surface is extremely large, and the risk of cracking of a large-volume structure is increased steeply. The system creatively provides a solution for uniformly cooling the large-volume UHPC concrete in all directions, namely front, back, up, down, left and right, and can intelligently realize that the temperature difference between the core and the surface is stabilized between 10 ℃ in the stages of maintenance, temperature rise and temperature reduction, thereby greatly reducing the cracking risk of the large-volume UHPC concrete structure and improving the engineering quality; meanwhile, because the absolute temperature rise of a large UHPC concrete structure is large, the traditional cooling time is long, the system adopts gradient constant-temperature water to quickly cool and can ensure that the temperature difference of the inner surface is within a controllable set value. The construction period is shortened, and the comprehensive cost of the project is effectively reduced.

Optional construction installation: the warm water recycling system comprises warm water recycling barriers 21 contained in the warm water recycling device 2, a drain pipe 22, a warm water recycling pool 23, a warm water circulating water suction pipe 24 and a warm water circulating pump 25.

Step two:

the host of the process intelligent control device 7 is internally provided with a self-control program for the large-volume ultra-high performance concrete thermal curing process, and the self-control elements, circuits and logic relations of the self-control elements, circuits and logic relations are comprehensively debugged to ensure that no error exists.

Step three:

an process intelligent control device 7 is started, a self-control program of the large-volume ultrahigh-performance concrete thermal curing process is operated, and the system automatically operates and detects the core temperature, the surface temperature, the temperature in the heat preservation shed 3, the temperature of cooling water and the temperature of a water storage area of the large-volume UHPC concrete 5 according to preset process parameters to start automatic watching;

step four: after the large-volume UHPC concrete is poured, the large-volume UHPC concrete generates hydration heat, so that the temperature of the large-volume UHPC concrete rises, the temperature rise speed of a core part is far greater than the temperature rise speed of the periphery, at the moment, a system automatically detects the temperature of the core part and the temperature of a surface layer according to a preset certain frequency, when the difference value is close to a preset allowable difference value, a process intelligent control device 7 sends a starting working instruction to a steam generating device 41 and an intelligent adjusting constant-temperature hot water source 61 to respectively prepare steam and constant-temperature hot water matched with a heating process, when the difference value between the temperature of the core part and the temperature of the surface layer reaches the preset allowable difference value, a large-volume ultrahigh-performance concrete thermal curing process automatic control program sends an instruction to open an automatic control steam valve 42, a constant-temperature water automatic control valve 642 and a flow control valve 643, steam of the steam generating device 41 is sent to a thermal insulation shed 3 through a steam uniform delivery pipe 43, the inner cavity of the steam heating heat preservation shed 3 and the front, the back, the left, the right, the top surface and the bottom surface of the large-volume UHPC concrete 5 are uniformly heated, the steam delivery quantity is synchronously adjusted according to the heating speed of the core part of the large-volume UHPC concrete 5, and the constant temperature water temperature and the supply flow of the constant temperature hot water source 61 are intelligently adjusted, so that the uniform and synchronous heating of the front, the back, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete is realized, and the temperature difference between the inside and the surface layer of the large-volume UHPC concrete is stably controlled; with the increase of the hydration heat in the large-volume UHPC concrete and the continuous rise of the temperature, the process intelligent control device 7 continuously synchronously adjusts the steam delivery volume according to the temperature rise speed of the core part of the large-volume UHPC concrete 5 and intelligently adjusts the constant-temperature water temperature and the supply flow of the constant-temperature hot water source 61, and continuously realizes the uniform and synchronous temperature rise of the front, the back, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete until the maximum limit temperature is raised to about 90 degrees generally.

Step five, when the large-volume UHPC concrete 5 reaches the temperature rise peak value and exceeds 80 ℃, the temperature of the large-volume UHPC concrete 5 is maintained at 80 ℃ or more for 72 hours, the process intelligent control device 7 is automatically switched from the temperature rise stage to the temperature reduction stage, and a self-control program of the large-volume ultrahigh-performance concrete thermal curing process, which is built in the process intelligent control device 7, sends an instruction: and closing the self-control steam valve 42 and the steam generating device 41, and reducing the temperature of the constant-temperature water of the intelligent-adjustment constant-temperature hot water source 61.

Step six:

21855and a constant-temperature cooling process; the self-control program for the thermal curing process of the large-volume ultrahigh-performance concrete instructs the intelligent adjustment of the temperature of the constant-temperature hot water source 61 to be adjusted to the set value of the actually measured temperature difference between the front, the back, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete. Simultaneously, automatically opening a first constant-temperature water automatic control valve 642, a first flow rate regulating valve 643, a third constant-temperature water automatic control valve 672, a third flow rate regulating valve 673, a second constant-temperature water automatic control valve 662 and a second flow rate regulating valve 663, supplying constant-temperature water with the temperature 5-25 ℃ lower than the temperature of the core part to the heating and cooling heat exchange pipe 64, the upper plane water pipe 661 and the vertical plane constant-temperature water cooling pipe 671, enabling the constant-temperature water to reach a proper flow rate, uniformly and controllably cooling the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete 5, rapidly carrying away the heat of the large-volume UHPC concrete 5 through the heat exchange between the constant-temperature water and the large-volume UHPC concrete 5, and synchronously and uniformly descending the external temperature of 6 surfaces of the large-volume UHPC concrete 5 in a constant-temperature water continuous circulation;

step seven: along with the gradual reduction of the core temperature, the intelligent-adjustment constant-temperature hot water source 41 is synchronously reduced, and is continuously circulated and circularly reduced until the temperature of the large-volume UHPC concrete core is reduced to be within 15 ℃ of the difference between the temperature of the large-volume UHPC concrete core and the atmospheric environment temperature, so that the large-volume UHPC concrete is thermally cured;

optional auxiliary processes:

when setting up warm water recycle device 2, warm water recycle encloses fender 21 and collects the warm water to discharge into warm water recovery pond 23 through drain pipe 22 in, warm water circulating pump 25 absorbs water the water in 24 with warm water recovery pond 23 through the warm water circulation and takes out recycle in intelligent regulation constant temperature hot water source 61, in continuous circulation, the water economy resource reduces the energy consumption.

While one embodiment of the present invention has been described in detail, the description is only a preferred embodiment of the present invention and should not be taken as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims

1. The large-volume ultrahigh-performance concrete thermal curing system is characterized by comprising a thermal insulation shed (3), a temperature rise adjusting device (4), large-volume UHPC concrete (5), a constant-temperature water cooling device (6) and a process intelligent control device (7); the heat preservation shed (3) is arranged above the large-volume UHPC concrete (5) and surrounds the large-volume UHPC concrete, and the heat preservation shed (3) is used for preserving heat of the large-volume UHPC concrete (5); temperature rise adjusting devices (4) are distributed on the periphery, the top surface and the bottom surface of the large-volume UHPC concrete (5), and the temperature rise adjusting devices (4) are used for synchronously raising the temperature of the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface, the top surface and the bottom surface of the large-volume UHPC concrete (5); constant-temperature water cooling devices (6) are distributed in all positions of the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface, the top surface and the bottom surface of the large-volume UHPC concrete (5), and the constant-temperature water cooling devices (6) are used for synchronously reducing the uniform cooling temperature of the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface, the top surface and the bottom surface of the large-volume UHPC concrete (5); constant-temperature water bottom heating and cooling heat exchange tubes (64) are distributed in the base (1) of the large-volume UHPC concrete (5), and the bottom heating and cooling heat exchange tubes (64) are used for uniformly heating and synchronously heating the bottom of the large-volume UHPC concrete (5) when the temperature is raised, and synchronously reducing the uniform cooling temperature when the temperature is lowered; the process intelligent control device (7) is arranged on the periphery of the large-volume UHPC concrete (5), temperature sensors of the process intelligent control device (7) are arranged at the core part, the surface layer, the inner cavity of the heat-preservation shed (3) and a constant-temperature hot water source of the large-volume UHPC concrete (5) and are used for detecting the real-time temperatures of the core part, the surface layer, the inner cavity of the heat-preservation shed and the hot water source, and when the temperature rises, the process intelligent control device (7) automatically sends out an instruction and controls -related valve elements to enable the temperature rise adjusting device (4) to start to convey heat, so that the uniform and controllable speed temperature rise of the core part and the surface layer of the large-volume UHPC concrete (5) is realized; when the temperature is reduced, the intelligent process control device (7) automatically sends an instruction and controls -related valve elements to enable the constant-temperature water cooling device (6) to convey constant-temperature water with the temperature lower than the temperature of the core part and to flow circularly, heat exchange is carried out by utilizing the temperature difference, the heat of the large-volume UHPC concrete (5) is rapidly taken away, and uniform and controllable speed cooling is realized; the structure and the function form a large-volume ultrahigh-performance concrete thermal curing system.

2. The thermal curing system for the large-volume ultrahigh-performance concrete according to claim 1, wherein the constant-temperature water cooling device (6) comprises an intelligent-adjustment constant-temperature hot water source (61), a constant-temperature hot water pump (62), a tee joint (63), a bottom heating and cooling heat exchange pipe (64), a first constant-temperature water automatic control valve (642), a first flow control valve (643) and a parallel main pipe (644), one side of the intelligent-adjustment constant-temperature hot water source (61) is connected with the constant-temperature hot water pump (62) through a pipeline, the other end of the constant-temperature hot water pump (62) is connected with the tee joint (63), one outlet of the tee joint (63) is connected with the parallel main pipe (644) of the bottom heating and cooling heat exchange pipe (64), the first constant-temperature water automatic control valve (642) and the first flow control valve (643) are distributed on the parallel main pipe (644) of the bottom heating and cooling heat exchange pipe (64), the bottom heating and cooling heat exchange tubes (64) are arranged in the base (1) side by side, most of the heat exchange tubes in the length direction are buried below the upper plane of the base by 0-30 cm, one end of each heat exchange tube is connected with a parallel header pipe (644) arranged on the ground of the base (1), and the other end of each heat exchange tube is bent to extend out of the upper plane of the base (1) to discharge circulating constant-temperature cooling water.

3. The thermal curing system for large-volume ultrahigh-performance concrete according to claim 2, wherein the bottom heating and cooling heat exchange tubes (64) are square flat tubes, and the distance between every two bottom heating and cooling heat exchange tubes (64) is 5-30 cm.

4. The large-volume ultrahigh-performance concrete thermal curing system as claimed in claim 3, wherein the constant-temperature water cooling device (6) further comprises a header pipe (65), an upper plane water pipe (661), a second constant-temperature water automatic control valve (662), a second flow rate control valve (663), a vertical-surface constant-temperature water cooling pipe (671), a third constant-temperature water automatic control valve (672) and a third flow rate control valve (673);

one other outlet of the tee joint (63) is connected with a main pipe (65), an upper plane water pipe (661) and a vertical surface constant temperature water cooling pipe (671) are sequentially arranged on the main pipe (65), a second constant temperature water automatic control valve (662) and a second flow control valve (663) are arranged on the upper plane water pipe (661), and the upper plane water pipe (661) is used for cooling water conveyed in a plane water storage area on the large-volume UHPC concrete (5);

the automatic temperature control water cooling system is characterized in that a third temperature control water automatic control valve (672) and a third flow control valve (673) are arranged on the vertical surface constant temperature water cooling pipe (671), the vertical surface constant temperature water cooling pipe (671) surrounds the upper side of the vertical surface edge on the periphery of the large-volume UHPC concrete (5), water outlet holes are uniformly formed in the bottom of the vertical surface constant temperature water cooling pipe (671), and the vertical surface constant temperature water cooling pipe (671) is used for spraying constant temperature water to the front vertical surface, the rear vertical surface, the left vertical surface and the right vertical surface of the large-volume UHPC concrete (5) for cooling.

5. The large-volume ultrahigh-performance concrete thermal curing system according to claim 1, wherein the temperature rise adjusting device (4) comprises a steam generating device (41), an automatic control steam valve (42), a steam uniform delivery pipe (43), a steam distribution hole (44), an intelligent adjusting constant-temperature hot water source (61), a constant-temperature hot water pump (62), a tee joint (63), a bottom heating and cooling heat exchange pipe (64), a constant-temperature water automatic control valve I (642), a flow rate control valve I (643) and a parallel header pipe (644), the steam generating device (41) is arranged on the periphery outside the large-volume UHPC concrete (5), a steam output pipe of the steam generating device (41) is communicated with the steam uniform delivery pipe (43), the steam uniform delivery pipe (43) is arranged on the lower bottom surface of the periphery outside the large-volume UHPC concrete (5), the input end of the steam uniform delivery pipe (43) is provided with the automatic control steam valve (42), a plurality of 0.2-3mm steam distribution holes (44) are uniformly formed in the steam uniform conveying pipe (43) close to the side direction of the heat preservation shed (3), when the difference between the core temperature and the surface layer temperature detected by the process intelligent control device (7) reaches a set value, an self-control steam valve (42) is opened, steam of the steam generating device (41) is conveyed into the heat preservation shed (3) through the steam uniform conveying pipe (43) and the steam distribution holes (44), and the periphery and the top of the large-volume UHPC concrete (5) absorb heat and raise the temperature to enable the temperature of the heat absorption part to rise at a preset rate to achieve synchronous rise with the temperature rise of core hydration heat; meanwhile, the process intelligent control device (7) sends an instruction to pump constant-temperature hot water of an intelligent regulation constant-temperature hot water source (61) by a constant-temperature hot water pump (62) at a water temperature higher than the preset value of the core temperature, after an constant-temperature water automatic control valve I (642) and a flow control valve I (643) are opened, the constant-temperature hot water higher than the preset value of the core temperature enters the inlet end of a bottom heating and cooling heat exchange tube (64), then the constant-temperature hot water flows out of the other end of the constant-temperature water automatic control valve I and enters a warm water recycling enclosure (21) at a certain preset flow rate, the temperature of the constant-temperature hot water in the bottom heating and cooling heat exchange tube (64) is higher than or equal to the core temperature, and the heat of the constant-temperature hot water is conducted to the bottom of the large-volume UHPC concrete (5) so that the temperature of the constant-temperature hot water rises at the preset rate and is synchronous with the temperature rise of hydration of the core.

6. The large-volume ultrahigh-performance concrete thermal curing system according to claim 1, wherein a warm water recycling device (2) is arranged around the large-volume UHPC concrete (5), the warm water recycling device (2) comprises a warm water recycling enclosure (21), a drain pipe (22), a warm water recycling pool (23), a warm water circulating water suction pipe (24) and a warm water circulating pump (25), the warm water recycling enclosure (21) is arranged around the thermal insulation shed (3), the drain pipe (22) is arranged on one side of the warm water recycling enclosure (21), the drain pipe (22) discharges the warm water in the warm water recycling enclosure (21) into the warm water recycling pool (23), the warm water recycling pool (23) is embedded in the base (1), the warm water recycling pool (23) is provided with the warm water circulating water suction pipe (24), and the other end of the warm water circulating water suction pipe (24) is communicated with the warm water circulating pump (25), the other end of the warm water circulating pump (25) is communicated with a circulating recycling warm water input pipe (69), and recycled warm water is input into a water pool of the intelligent regulating constant-temperature hot water source (61).

7. The thermal curing system for mass ultra-high performance concrete according to claim 6, wherein the warm water recycling fence (21) has a height of 0.5cm to 25 cm.

8. The system of claim 1, wherein: the heat preservation shed (3) is a front, rear, left, right and top closed space structure, the sealing structure (31) is arranged on the periphery of the lower part of the heat preservation shed and the upper plane of the base (1), the heat preservation layer of the heat preservation shed (3) is at least arranged more than two layers, the inner layer is a waterproof layer, and the outer layer is a heat preservation material layer.

9. The large-volume ultrahigh-performance concrete thermal curing system as recited in claim 1, wherein said process intelligent control device (7) comprises a PLC (70) and a temperature sensor (71), a temperature sensor (72), a temperature sensor (73), a temperature sensor (74), a temperature sensor (75), a temperature sensor (76), a temperature sensor (77), a temperature sensor (78), a temperature sensor (79), a temperature sensor (710), a first flow regulating valve (711), a second flow regulating valve (712), a third flow regulating valve (713), a first automatic valve (714), a second automatic valve (715), a third automatic valve (716) and a fourth automatic valve (717), said temperature sensor (71) is arranged in a core of a large-volume UHPC concrete (5), and the front, rear, left and right vertical faces and a top face of said large-volume UHPC concrete (5) are arranged in the core of said large-volume UHPC concrete (5), Temperature sensor (72), temperature sensor (73), temperature sensor (74), temperature sensor (75), temperature sensor (76), temperature sensor (77) have been laid respectively to the bottom surface, temperature sensor (78) have been laid to the inside of thermal-insulation shed (3), temperature sensor (79) have been laid to bulky UHPC concrete (5) top water storage area, temperature sensor (710) have been laid to intelligent regulation constant temperature hot water source (61) inside, temperature sensor (71), temperature sensor (72), temperature sensor (73), temperature sensor (74), temperature sensor (75), temperature sensor (76), temperature sensor (77), temperature sensor (78), temperature sensor (79), temperature sensor (710), flow control valve (711), flow control valve two (712), flow control valve three (713), The first automatic control valve (714), the second automatic control valve (715), the third automatic control valve (716) and the fourth automatic control valve (717) are all in wired connection with a PLC (70) of the intelligent process control device (7), and the intelligent process control device (7) automatically detects the temperature of a core temperature sensor (71), a surface temperature sensor (72), a temperature sensor (73), a temperature sensor (74), a temperature sensor (75), a temperature sensor (76) and a temperature sensor (77) of the large-volume UHPC concrete (5); the temperature of a temperature sensor (78) in the heat-preservation shed (3) and the temperature of a top water storage area temperature sensor (79) are adjusted, the temperature of an internal temperature sensor (710) of a constant-temperature hot water source (61) is adjusted, the internal and external temperature difference of the large-volume UHPC concrete (5) is automatically calculated, whether the internal and external temperature difference is a set value or not is judged, when the internal and external temperature difference reaches a preset condition in a heating stage, an opening instruction is automatically sent to a first automatic control valve (714), a second automatic control valve (715), a third automatic control valve (716) and a fourth automatic control valve (717), and the constant-temperature hot water pump (62) and the steam generating device (41) work to provide heat sources for the large-volume UHPC concrete (5) so that the large-volume UHPC concrete (5) can be uniformly and stably heated in the controllable temperature difference; when the large-volume UHPC concrete (5) reaches the temperature rise peak value and exceeds 80 ℃, the system automatically maintains the temperature of the large-volume UHPC concrete (5) to be above 80 ℃ for 72 hours; the process intelligent control device (7) automatically sends out an instruction: closing the self-control steam valve (42) and the steam generating device (41), reducing the constant temperature water temperature of the intelligent-adjustment constant temperature hot water source (61), and simultaneously, instructing the constant temperature water temperature of the intelligent-adjustment constant temperature hot water source (61) to be reduced to a set value of actually measured temperature difference between the front, back, left, right, top surface, bottom surface and the core part of the large-volume UHPC concrete; automatically opening a first constant-temperature water automatic control valve (642), a first flow control valve (643), a third constant-temperature water automatic control valve (672), a third flow control valve (673), a second constant-temperature water automatic control valve (662) and a second flow control valve (663), supplying constant-temperature water with the temperature of 5-25 ℃ lower than the temperature of the core part to enable the constant-temperature water to reach a proper flow, uniformly and controllably cooling the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete (5), gradually reducing the temperature of the core part of the large-volume UHPC concrete (5) along with the time, synchronously reducing an intelligent regulation constant-temperature hot water source (41) and continuously and circularly reducing the temperature until the temperature of the core part of the large-volume UHPC concrete is reduced to be within 15 ℃ of the difference of the atmospheric environment temperature, and finishing the thermal curing of the large-volume UHPC concrete (5).

10. The thermal curing process of the large-volume ultrahigh-performance concrete thermal curing system is characterized by comprising the following steps of:

firstly, the following preliminary preparation construction is carried out:

a construction base (1) is constructed, and bottom heating and cooling heat exchange tubes (64) and accessories are constructed and embedded;

installing structural steel bars and accessories of the large-volume UHPC concrete (5); installing a temperature sensor (71), a temperature sensor (72), a temperature sensor (73), a temperature sensor (74), a temperature sensor (75), a temperature sensor (76), a temperature sensor (77) which are preset in the large-volume UHPC concrete (5), installing surrounding vertical face templates (51) of the large-volume UHPC concrete (5), pouring the UHPC concrete (5), spraying water mist on the top surface of the UHPC concrete, and covering a moisture retention film;

after the preparation construction is finished, the following thermal curing process is carried out on the large-volume UHPC concrete (5):

the method comprises the following steps:

installing an intelligent adjusting constant-temperature hot water source (61), a constant-temperature hot water pump (62), a tee joint (63), a bottom heating, a constant-temperature water automatic control valve I (642), a flow control valve I (643), a parallel main pipe (644), a steam generating device (41), an automatic control steam valve (42), a steam uniform delivery pipe (43) and a steam distribution hole (44) around and on a large-volume UHPC concrete (5);

connecting and installing a control signal and action element connecting line between the process intelligent control device (7) and the temperature measuring sensor and a host of the process intelligent control device (7);

installing and constructing a heat preservation shed (3), and constructing a sealing structure (31) between the periphery of the bottom of the heat preservation shed and the base (1);

optional construction installation: warm water contained in the warm water recycling device (2) is recycled and is enclosed by a baffle (21), a drain pipe (22), a warm water recycling pool (23), a warm water circulating water suction pipe (24) and a warm water circulating pump (25);

step two:

the respective control elements, circuits and logic relations are comprehensively debugged in the process intelligent control device (7) to ensure no error;

step three:

opening a process intelligent control device (7), automatically operating and detecting the core temperature, the surface temperature, the internal temperature of the heat preservation shed (3), the temperature of the cooling water and the temperature of the water storage area of the large-volume UHPC concrete (5) according to preset process parameters, and starting automatic watching;

step four: after the large-volume UHPC concrete is poured, the large-volume UHPC concrete generates hydration heat, so that the temperature of the large-volume UHPC concrete rises, the temperature rise speed of a core part is far larger than the temperature rise speed of the periphery, at the moment, a system automatically detects the temperature of the core part and the temperature of a surface layer according to a preset certain frequency, when the difference value of the core part temperature and the surface layer temperature is close to a preset allowable difference value, a process intelligent control device (7) sends a starting working instruction to a steam generating device (41) and an intelligent adjusting constant-temperature hot water source (61) to respectively prepare steam and constant-temperature hot water matched with a heating process, when the difference value of the core part temperature and the surface layer temperature reaches the preset allowable difference value, the process intelligent control device (7) sends an instruction to open an automatic control steam valve (42), a constant-temperature water automatic control valve I (642) and a flow control valve I (643), steam of the steam generating device (41) sends a proper amount of steam to a heat preservation shed (3) through a steam uniform conveying pipe (43), the inner cavity of the steam heating heat preservation shed (3) and the front, the back, the left, the right, the top surface and the bottom surface of the large-volume UHPC concrete (5) are uniformly heated, the steam delivery quantity is synchronously adjusted according to the heating speed of the core part of the large-volume UHPC concrete (5), and the constant temperature water temperature and the supply flow of the constant temperature hot water source (61) are intelligently adjusted, so that the uniform and synchronous heating of the front, the back, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete is realized, and the temperature difference between the inside and the surface layer of the large-volume UHPC concrete is stably controlled; with the increase of hydration heat in the large-volume UHPC concrete and the continuous rise of temperature, the process intelligent control device (7) continuously synchronously adjusts the steam delivery quantity according to the temperature rise speed of the core part of the large-volume UHPC concrete (5) and intelligently adjusts the constant-temperature water temperature and supply flow of the constant-temperature hot water source (61), and continuously realizes the uniform and synchronous temperature rise of the front, back, left, right, top and bottom surfaces of the large-volume UHPC concrete and the core part until the temperature rises to the highest limit temperature;

step five, when the large-volume UHPC concrete (5) reaches the temperature rise peak value and exceeds more than 80 ℃, maintaining the temperature of the large-volume UHPC concrete (5) at more than 80 ℃ for 72 hours, automatically switching the process intelligent control device (7) from the temperature rise stage to the temperature reduction stage, and sending an instruction by the process intelligent control device (7): closing the self-control steam valve (42) and the steam generating device (41), and reducing the temperature of the constant-temperature water of the intelligent regulation constant-temperature hot water source (61);

step six:

21855and a constant-temperature cooling process; the process intelligent control device (7) instructs the intelligent adjustment of the constant temperature water temperature of the constant temperature hot water source (61) to be adjusted to the actually measured temperature difference set values of the front, the rear, the left, the right, the top surface, the bottom surface and the core part of the large-volume UHPC concrete; simultaneously automatically opening a first constant-temperature water automatic control valve (642), a first flow regulating valve (643), a third constant-temperature water automatic control valve (672), a third flow regulating valve (673), a second constant-temperature water automatic control valve (662) and a second flow regulating valve (663), constant temperature water with the temperature 5-25 ℃ lower than the temperature of the core part is supplied to the heating and cooling heat exchange pipe (64), the upper plane water conveying pipe (661) and the vertical surface constant temperature water cooling pipe (671) to achieve the proper flow rate, uniformly cooling the front, rear, left and right vertical surfaces, the top surface and the bottom surface of the large-volume UHPC concrete (5) at a controllable rate, through the heat exchange between the constant temperature water and the large-volume UHPC concrete (5), the temperature of the lower constant temperature water rises, the heat of the large-volume UHPC concrete (5) is quickly taken away, in constant temperature water continuous circulation, the external temperature of 6 surfaces of the large-volume UHPC concrete (5) is synchronously, orderly and uniformly reduced;

step seven: along with the gradual reduction of the core temperature, the intelligent-adjustment constant-temperature hot water source (41) is synchronously reduced, and is continuously circulated and circularly reduced until the temperature of the large-volume UHPC concrete core is reduced to be within 15 ℃ of the difference between the temperature of the large-volume UHPC concrete core and the atmospheric environment temperature, so that the large-volume UHPC concrete is thermally cured;

optional auxiliary processes:

when setting up warm water recycle device (2), warm water recycle encloses fender (21) and collects the warm water to discharge into warm water recovery pond (23) through drain pipe (22), warm water circulating pump (25) absorb water pipe (24) through the warm water circulation and take out water among the warm water recovery pond (23) and take recycle in intelligent regulation constant temperature hot water source (61), in continuous circulation, the water economy resource reduces the energy consumption.