Concrete regulation and control system and method integrating heat recovery, spraying and gradient control

Abstract

The invention provides a concrete regulation and control system and method integrating heat recovery, spraying and gradient control, and relates to the technical field of concrete curing, and the concrete regulation and control system comprises a temperature sensing element and a humidity sensing element which are mounted on reinforcing steel bars in a concrete structure in a layered manner in the depth direction; the cooling water circulating system comprises a water pump and a cooling water pipe, and the cooling water pipe is arranged in the mass concrete structure and externally connected with a variable frequency circulating pump; the double-water-tank system is matched with the heater to realize graded regulation of water temperature; the automatic spraying system is connected with the integrated electric heating module; the heat recovery and circulation assembly is connected with an outlet of a cooling water pipe in the concrete, recovers concrete hydration heat brought out by the cooling water pipe, and transfers heat of high-temperature cooling water with the temperature being 50 DEG C or above to the phase change heat storage tank; the central control unit continuously receives and records monitoring data of the temperature sensor and the humidity sensor and analyzes the monitoring data in real time, and when the temperature gradient or the humidity gradient exceeds the limit, a gradient field control instruction is automatically triggered to achieve energy efficiency maximization.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete curing, and more specifically, particularly relates to a concrete regulation system and method integrating heat recovery, spraying and gradient control. Background Art

[0002] Mass concrete is widely used in large building floors, bridge abutments and equipment foundations, etc. Due to its large volume, significant internal and external temperature differences are generated due to hydration heat during the hardening process. The internal humidity gradient will intensify the shrinkage stress and at the same time affect the distribution of the temperature gradient, resulting in temperature cracks and dry shrinkage cracks. Therefore, effective temperature control measures must be taken during the construction process to eliminate the cracking risk.

[0003] Traditional methods use a single cooling water pipe or surface sprinkling for curing, which have certain limitations. First, after the mass concrete is poured, the problem of stable heat dissipation and cooling of the hydration heat inside the structure. There are already relevant technologies in this regard, such as using circulating water to cool down, but this method still relies on manual management and does not cooperate with the internal temperature detection system of the mass concrete. Construction workers can only carry out the cooling water circulation based on experience, and it is difficult to achieve the purpose of real-time and stable heat dissipation of the internal temperature of the mass concrete. In addition, the existing curing technologies ignore the contribution of the internal humidity gradient to the cracks, and the humidity gradient will further affect the temperature gradient. Second, the curing of mass concrete has strict requirements for temperature. According to the specification requirements, the temperature difference between the surface temperature of the mass concrete and the atmosphere should be less than 25°C, and the temperature difference between the curing water temperature and the concrete surface should not be greater than 15°C. The spraying water temperature of the existing curing technologies is not adjusted in real time according to the ambient temperature, resulting in the frequent breakthrough of the 25°C specification limit of the temperature difference between the surface temperature of the mass concrete and the atmosphere. In addition, the high-temperature water in the cooling water pipe is mostly naturally cooled, and the waste heat is not well utilized. Although the existing patents propose distributed temperature monitoring, they do not solve the problems of humidity gradient quantification and waste heat recycling. For example, a mass concrete curing system and its construction method disclosed in Chinese Patent CN117661873 realizes the automatic and intelligent curing of mass concrete through the combination of a control switch, a temperature detection element, a composite layer, a cooling water circulation system, and a humidity compensation system, but does not clarify the waste heat recovery mechanism, the energy efficiency improvement is limited, and the temperature and humidity gradient collaborative control model is not mentioned, and the crack risk function is not quantified. Chinese Patent CN216920343U discloses a curing structure for super-high-rise and super-thick raft slab concrete, which solves the problem of too high center temperature of super-high-rise and super-thick raft slab concrete, and then controls the generation and development of concrete cracks, but does not integrate temperature and humidity sensors, cannot dynamically adjust the spraying and cooling strategies, and the waste heat is only used for surface heat preservation, and no heat recovery device (such as a plate heat exchanger) is designed.

[0004] Therefore, there is an urgent need to develop a system that integrates temperature and humidity gradient control and energy recovery. In view of the problems existing in the existing large-volume concrete curing technology, such as single temperature and humidity control, waste of waste heat, and dependence on manual regulation, a large-volume concrete gradient control system and method based on heat recovery and intelligent spraying are designed. By using distributed fiber optic sensors to monitor the internal temperature-humidity gradient of concrete in real time and combining with an infrared thermal imager to capture the surface temperature field, three-dimensional dynamic data fusion is achieved. At the same time, the waste heat of cooling water is recovered in stages through a plate heat exchanger (high-temperature water is stored in a phase change heat storage tank, and medium- and low-temperature water is used to preheat the spray), and based on a multi-objective optimization model (crack risk function R = αΔT + β(dT / dt) + γΔH), the cooling water flow rate and spraying strategy are dynamically adjusted, and finally a double-gradient closed-loop control of temperature and humidity is formed. This system can be widely applied to large-volume concrete structures such as dams and high-rise building foundations, significantly reducing the crack incidence rate (expected to be reduced by ≥30%), improving the energy utilization rate (waste heat recovery rate ≥40%), while reducing manual intervention and resource waste, and having significant economic benefits and engineering practical value. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a concrete control system and method that integrates heat recovery, spraying, and gradient control to solve the above problems.

[0006] A concrete control system that integrates heat recovery, spraying, and gradient control includes:

[0007] Temperature-humidity gradient sensing network: It is composed of distributed fiber optic temperature sensors, distributed fiber optic humidity sensors buried in layers along the depth direction of the concrete, an infrared thermal imager arranged on the surface of the concrete, and a surface humidity sensor, and is used to monitor the temperature field and humidity gradient inside and on the surface of the concrete in real time;

[0008] Cooling water circulation system: It includes a variable-frequency water pump, a serpentine cooling water pipe arranged inside the concrete, and a plate heat exchanger connected to the outlet of the cooling water pipe. The serpentine cooling water pipe is used to circulate cooling water to take away the hydration heat of the concrete, and the variable-frequency water pump adjusts the water flow rate according to the instructions of the central control unit;

[0009] Intelligent spraying subsystem: It includes electromagnetic nozzles with annular zoning and an electric heating module. The electromagnetic nozzles support the switching between atomization and direct current dual modes, and the spraying water temperature is adjusted by the heat recovery system;

[0010] Heat recovery circulation device: It includes a plate heat exchanger and a phase change heat storage tank, and is used to store the waste heat of high-temperature cooling water in stages and provide preheated medium- and low-temperature water to the spraying system;

[0011] Central control unit: Dynamically adjusts the cooling water flow rate, spraying mode, and waste heat distribution strategy based on temperature and humidity gradient data. It has a built-in multi-objective optimization model with the minimization of the crack risk function R = αΔT + β(dT / dt) + γΔH as the ultimate goal, where ΔT is the maximum temperature difference between the inside and outside of the concrete, ΔH is the internal humidity gradient, dT / dt is the maximum temperature difference change rate, and α, β, and γ are empirical coefficients.

[0012] Preferably, the mode switching logic of the intelligent spraying subsystem is as follows:

[0013] When the internal humidity gradient > 15% RH / m or the internal temperature difference gradient ΔT / d > 15 °C / m, start atomized spraying (particle size ≤ 50 μm);

[0014] When the core temperature > 60 °C and the core layer humidity < 80% RH, switch to direct current spraying (flow rate ≥ 10 L / min) and inject pre-cooled circulating water.

[0015] Preferably, the hierarchical utilization strategy of the heat recovery cycle device includes:

[0016] High-temperature cooling water (> 50 °C) is preferentially stored in the phase change heat storage tank, and the phase change material is paraffin or inorganic salt, with a phase change temperature of 40 - 60 °C;

[0017] Medium and low-temperature water (30 - 50 °C) is supplied to the spray electric heating module after secondary circulation through a plate heat exchanger.

[0018] Preferably, the distributed optical fiber humidity sensor uses an optical fiber grating array, with a humidity sensitive unit arranged every 0.5 m along the concrete depth direction. The humidity measurement range is 20 - 100% RH, and the accuracy is ±3% RH;

[0019] The humidity sensitive unit is encapsulated in a porous ceramic sheath to directly contact the internal environment of the concrete.

[0020] Preferably, the multi-objective optimization model built in the central control unit uses the crack risk function:

[0021] R = αΔT + β(dT / dt) + γΔH as the objective function, and realizes the coordinated control of the internal temperature and humidity gradient of the concrete by adjusting the rotation speed of the variable frequency water pump, the mode of the electromagnetic nozzle, and the heat distribution of the phase change heat storage tank.

[0022] Preferably, the cooling water pipe is made of 304 stainless steel, with an inner diameter of 25 mm, arranged in a serpentine shape along the internal steel bar grid of the concrete, with a horizontal spacing of 0.8 - 1.2 m and a vertical spacing of 0.6 - 1.0 m. The outlet end is connected to the plate heat exchanger through a flange.

[0023] Preferably, the electromagnetic nozzle is installed at a height of 0.3 - 0.5 m from the concrete surface, with an inclination angle of 15° - 30°, arranged in a grid partition of 5 m × 5 m, and the coverage area of a single nozzle is 8 - 12 ㎡.

[0024] Preferably, the capacity of the phase change heat storage tank is determined according to the volume of concrete, and 0.1 - 0.2 m 3 of heat storage volume is configured for each cubic meter of concrete, and a spiral guide plate is built-in to improve the heat exchange efficiency.

[0025] Another technical problem to be solved by the present invention is to provide a gradient temperature control method, including the following steps:

[0026] S1: Obtain the internal temperature - humidity gradient data of concrete through a distributed optical fiber temperature sensor and a distributed optical fiber humidity sensor, generate a surface temperature field in combination with an infrared thermal imager, and form a three-dimensional temperature and humidity distribution map;

[0027] S2: When the temperature of the core layer exceeds 60°C or the internal humidity gradient > 15% RH / m, the central control unit starts a variable-frequency water pump, pre-cools the cooling water to 5 - 25°C through a plate heat exchanger and injects it into the internal pipe network of the concrete, and at the same time recovers the heat of the high-temperature water above 50°C at the outlet end to the phase change heat storage tank;

[0028] S3: Dynamically select the spraying mode according to the surface humidity sensor and the internal humidity gradient data: start atomizing spraying (frequency ≥ once every 30 minutes) when the humidity gradient > 15% RH / m, and switch to direct current spraying and add 1 - 3% curing agent when the humidity of the core layer < 75% RH.

[0029] Preferably, the flow rate of the cooling water in S2 is dynamically adjusted according to the temperature difference gradient. When ΔT / d > 20°C / m, the flow rate is set to 50 m 3 / h, when 10°C / m ≤ ΔT / d ≤ 15°C / m, the flow rate is reduced to 20 m 3 / h until the temperature difference gradient is stabilized within 10°C / m.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] In the present invention, a three-dimensional monitoring network is constructed through a distributed optical fiber temperature sensor and a humidity sensor to capture the internal temperature difference gradient (ΔT / d) and humidity gradient (ΔH) of concrete in real time. In combination with the multi-objective optimization model built into the central control unit, the flow rate of the cooling water and the spraying strategy are dynamically adjusted. When the internal temperature difference gradient exceeds 15°C / m or the humidity gradient > 15% RH / m, atomizing spraying or direct current cooling is automatically started to control the temperature difference gradient within 10°C / m and the humidity gradient ≤ 10% RH / m, reducing the incidence of cracks compared with the traditional single temperature control process, and effectively solving the cracking problem of mass concrete caused by hydration heat and humidity shrinkage.

[0032] In the present invention, the high-temperature water (>50°C) at the outlet of the cooling water pipe transfers heat to the phase change heat storage tank through a plate heat exchanger for storage, and the medium-low temperature water (30 - 50°C) is used to preheat the spraying system, achieving a waste heat recovery rate of ≥40%. Compared with the traditional process of directly discharging high-temperature cooling water, the present invention can reduce the cooling energy consumption. At the same time, by utilizing the heat storage characteristics of phase change materials (paraffin / inorganic salts), it provides preheating for the spraying water at night or in a low-temperature environment, reducing the energy consumption of the electric heating module. The overall energy utilization efficiency is significantly improved, meeting the concept of green construction.

[0033] In the present invention, the electromagnetic nozzle supports the dual-mode switching of atomization (particle size ≤50μm) and direct current (flow rate ≥10L / min), and dynamically adjusts the spraying strategy according to real-time monitoring data: when the humidity gradient is on the high side, atomized spraying is started to uniformly supplement the surface moisture; when the core temperature >60°C and the humidity is insufficient, it switches to the direct current mode and injects pre-cooled circulating water to precisely control the temperature and humidity environment. At the same time, the spraying water temperature is adjusted by the heat recovery system to ensure that the temperature difference from the concrete surface is ≤15°C, avoiding the risk of sudden temperature drop caused by traditional cold water spraying, improving the refinement and intelligence level of the curing process, and reducing manual intervention.

[0034] In the present invention, the system adopts a modular integrated design of four major modules: distributed optical fiber sensing network, cooling water circulation, intelligent spraying, and heat recovery. It is convenient to install and can be flexibly adjusted according to the concrete volume (such as configuring 0.1 - 0.2m 3 phase change heat storage tank) per cubic meter of concrete. The central control unit communicates with equipment such as frequency conversion water pumps and electromagnetic nozzles in real time through PLC, and automatically executes monitoring, adjustment, and warning tasks throughout the cycle, reducing manual operation errors and shortening the curing cycle. At the same time, both the sensors and the actuating components are designed to be high-temperature resistant and waterproof (such as stainless steel cooling water pipes and epoxy resin-sealed terminal blocks), adapting to harsh construction environments and improving the stability and safety of the system.

[0035] In the present invention, it is applicable to various large-volume concrete structures such as dams, high-rise building foundations, and bridge footings. Through the hierarchical temperature control and humidity compensation strategy, it can meet the curing requirements of different seasons (such as high temperature in summer and low temperature in winter) and structural thicknesses. For example, in summer, the core temperature is reduced by pre-cooled circulating water and atomized spraying, and in winter, the phase change heat storage tank is used to preheat the spraying water to maintain the surface temperature, avoiding the fluctuation of curing effects caused by seasonal differences in traditional processes. The popularization and application of this system can significantly improve the quality of concrete construction, reduce maintenance costs, and promote the upgrading of the civil engineering field towards intelligence and greenness. Brief Description of the Drawings

[0036] Figure 1 is a structural schematic diagram of the system of the present invention;

[0037] Figure 2This is the specific implementation flowchart of the present invention;

[0038] Figure 3 This is the elevation schematic diagram of the layout of the cooling water pipes in the present invention;

[0039] Figure 4 This is the plan schematic diagram of the horizontal layout of the cooling water pipes in the present invention;

[0040] Figure 5 This is the plan schematic diagram of the longitudinal layout of the cooling water pipes in the present invention;

[0041] Figure 6 This is the perspective view of the arrangement of the temperature and humidity sensors inside and on the surface of the mass concrete.

[0042] In the figure, the corresponding relationship between the component names and the drawing numbers is as follows: 1. Distributed optical fiber temperature sensor; 2. Infrared thermal imager; 3. Surface humidity sensor; 4. Electromagnetic spray head; 5. Electric heating module; 6. Variable frequency water pump; 7. Plate heat exchanger; 8. Phase change heat storage tank; 9. Central control unit; 10. Distributed optical fiber humidity sensor. Specific Embodiments

[0043] The following further describes in detail the implementation manners of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0044] Please refer to Figures 1 - 6 , the present invention provides a concrete regulation system and method integrating heat recovery, spraying and gradient control, specifically as follows:

[0045] 1. System hardware deployment and installation:

[0046] 1.1 Construction of the temperature and humidity gradient sensing network:

[0047] Distributed optical fiber temperature sensor 1: Buried in layers at a spacing of 0.5 m along the depth direction of the mass concrete structure, using high-temperature resistant optical fiber (working temperature -40°C to 80°C), fixed to the reinforcement cage nodes through binding straps, and each optical fiber is connected in series with 10 - 20 temperature sensitive units (accuracy ±0.5°C), covering the concrete core layer (center) to the surface layer (within 0.3 m from the surface).

[0048] Distributed optical fiber humidity sensor 10: Using an optical fiber grating array, each humidity sensitive unit is encapsulated in a porous ceramic sheath (pore diameter 5 - 10 μm), in direct contact with the concrete, arranged one every 0.5 m along the depth direction, with a measurement range of 20 - 100% RH and an accuracy of ±3% RH, and integrated with the temperature sensor on the same transmission bus through an optical fiber fusion splicer.

[0049] Surface monitoring equipment: Capacitive surface humidity sensors 3 are arranged on the concrete surface in a 5m×5m grid, and the wiring terminals are sealed with epoxy resin; infrared thermal imagers 2 are installed simultaneously, and the bracket is fixed on the inner side of the template. The field of view covers the entire surface to be measured, with a resolution of 0.1℃, and real-time capture of the two-dimensional temperature field.

[0050] 1.2 Cooling water circulation system installation:

[0051] Cooling water pipe layout: 304 stainless steel serpentine pipe (inner diameter 25mm, wall thickness 2mm) is used, and it is welded and fixed along the steel grid inside the concrete with a horizontal spacing of 0.8-1.2m and a vertical spacing of 0.6-1.0m. The inlet and outlet ends are connected to the plate heat exchanger 7 through flanges, and thermal conductive silicone grease is applied on the surface of the pipe to enhance the heat exchange efficiency.

[0052] Variable frequency pump 6: Model: Grundfos CRN5-10, flow range: 5-50m 3 / h, lift 30m, rubber shock-absorbing throats are installed on the inlet and outlet, and communicate with the central control unit 9 through the PLC control module.

[0053] 1.3 Intelligent sprinkler subsystem deployment:

[0054] Electromagnetic sprinkler 4: Arranged in an annular partition, the installation height is 0.3-0.5m from the concrete surface, the inclination angle is 20°, a single sprinkler covers an area of 10㎡, supports dual modes of atomization (particle size ≤50μm) and direct current (flow rate 15L / min), and is connected to the annular sprinkler network through a DN20 stainless steel pipe.

[0055] Electric heating module 5: power 30kW, built-in temperature sensor (accuracy ±1°C), input end connected to phase change heat storage tank 8 and plate heat exchanger 7, output end water temperature control accuracy ±2°C.

[0056] 1.4 Heat recovery cycle device construction:

[0057] Plate heat exchanger 7: Model APVM10-B, heat exchange area 15㎡, cooling water side and spray water side independent circulation, high temperature cooling water (>50℃) is cooled to 30-40℃ after heat exchange, and medium and low temperature water (30-50℃) is supplied to the spray system.

[0058] Phase change heat storage tank 8: The capacity is configured according to the concrete volume (0.15m3 per cubic meter of concrete 3 Thermal storage volume), built-in paraffin phase change material (phase change temperature 45-55℃), the outside of the tank is covered with a 50mm thick rubber and plastic insulation layer (thermal conductivity ≤0.034W / (m·K)).

[0059] 2. System operation and control process:

[0060] 2.1 Data collection and preprocessing:

[0061] After the concrete pouring is completed, the central control unit 9 receives the data of the distributed optical fiber sensor at a frequency of 1 time per second and calculates in real time:

[0062] Internal temperature difference gradient ΔT / d (temperature difference between the core layer and the surface layer / structural thickness);

[0063] Humidity gradient ΔH (humidity difference between the core layer and the surface layer / structural thickness);

[0064] Rate of change of temperature difference dT / dt (unit: °C / h).

[0065] The infrared thermal imager 2 generates a surface temperature cloud map every 5 minutes, which is fused with the internal temperature data to form a three-dimensional temperature and humidity field model.

[0066] 2.2 Cooling water circulation control:

[0067] Starting condition: When the core layer temperature > 60°C or ΔT / d > 15°C / m, the central control unit 9 sends an instruction to the variable frequency water pump 6 to inject pre-cooled circulating water at an initial flow rate of 30 m 3 / h at 5 - 25°C (the water temperature is adjusted by the plate heat exchanger 7).

[0068] Dynamic adjustment:

[0069] If ΔT / d > 20°C / h, the flow rate is increased to 50 m 3 / h;

[0070] If 10°C / m ≤ ΔT / d ≤ 15°C / m, the flow rate is reduced to 20 m 3 / h;

[0071] When ΔT / d ≤ 10°C / m and the core temperature < 50°C, the cooling water circulation is automatically stopped.

[0072] Waste heat recovery: The high-temperature water (> 50°C) at the outlet of the cooling water pipe transfers heat to the phase change heat storage tank 8 through the plate heat exchanger 7, and the medium and low-temperature water (30 - 50°C) enters the spray electric heating module 5 for preheating.

[0073] 2.3 Intelligent spraying strategy:

[0074] Atomized spraying mode: Trigger condition: Internal humidity gradient > 15% RH / m or ΔT / d > 15°C / m; Execution parameters: The atomization particle size of the nozzle ≤ 50 μm, the single spraying duration is 5 minutes, the interval is 30 minutes, and the spraying water temperature is 35 - 50°C (preheated by the phase change heat storage tank).

[0075] DC Spraying Mode: Trigger Condition: Core temperature > 60°C and core layer humidity < 80% RH; Execution Parameters: Flow rate 15 L / min, add 1 - 3% concrete curing agent (composition: acrylic resin emulsion) to the spraying water until the core layer humidity ≥ 85% RH.

[0076] 2.4 Hierarchical Utilization of Waste Heat:

[0077] High-temperature Water Storage: When the cooling water outlet temperature > 50°C, preferentially store the heat in the phase change heat storage tank 8, and accelerate the heat exchange through the spiral guide plate (the heat storage efficiency is increased by 20%).

[0078] Utilization of Medium and Low-temperature Water: The 30 - 50°C cooling water undergoes secondary circulation through the plate heat exchanger 7 to provide preheating for the spraying electric heating module 5, reducing the electric heating energy consumption by more than 40%.

[0079] Construction Steps and Parameters:

[0080] Sensor Embedding:

[0081] 24 hours before pouring, mark the sensor positions on the steel bar framework according to the design drawings. The distributed optical fiber temperature / humidity sensors are fixed to the steel bar joints through binding straps, and the humidity sensor sheath faces the inside of the concrete.

[0082] Installation of Cooling Water Pipes:

[0083] The serpentine water pipes are welded to the steel bar grid, with a horizontal spacing of 1.0 m and a vertical spacing of 0.8 m. Flange interfaces are reserved at the inlet and outlet ends. After the pipe surface is coated with thermal conductive silicone grease, it is wrapped with an aluminum foil reflective layer.

[0084] Commissioning of the Spraying System:

[0085] Calibrate the angle of the electromagnetic nozzle to 20°. Adjust the atomization mode pressure to 0.3 MPa (atomization particle size ≤ 50 μm) and the DC mode pressure to 0.5 MPa (flow rate 15 L / min) through a pressure tester.

[0086] System Calibration:

[0087] The temperature sensor is calibrated by a blackbody furnace (accuracy ±0.5°C), the humidity sensor is calibrated in a saturated salt solution (error ±3% RH), and the infrared thermal imager is corrected by a standard temperature plate.

[0088] Full-cycle Monitoring:

[0089] Monitor in real time after pouring. Start the temperature difference gradient warning at the first peak of hydration heat (about 12 - 36 hours). When ΔT / d ≤ 10°C / m and ΔH ≤ 10% RH / m for 72 consecutive hours, the system enters the low-power mode (monitoring frequency is reduced to 1 time / 10 minutes).

[0090] 4. Key Component Parameter Table:

[0091]

[0092]

[0093] Through the collaborative control of temperature and humidity gradients and waste heat recovery, the present invention achieves:

[0094] Reduction of crack risk: The temperature difference gradient is controlled within 10 °C / m, the humidity gradient ≤ 10% RH / m, and the crack incidence rate is reduced by 35% compared with the traditional method;

[0095] Improvement of energy efficiency: The waste heat recovery rate reaches 45%, the energy consumption of the spray system is reduced by 60%, and the cooling water consumption is reduced by 40%;

[0096] Intelligent construction: Full-cycle automatic control, reducing manual intervention by more than 80%, meeting the requirements of the "Code for Construction of Mass Concrete" (GB50496-2018).

[0097] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific purposes.

Claims

1. An integrated heat recovery, spray and gradient control concrete regulation system, characterized in that, Including: Temperature-humidity gradient sensing network: It is composed of distributed optical fiber temperature sensors (1), distributed optical fiber humidity sensors (10) buried in layers along the depth direction of the concrete, an infrared thermal imager (2) arranged on the concrete surface, and a surface humidity sensor (3), and is used to monitor the temperature field and humidity gradient inside and on the surface of the concrete in real time; Cooling water circulation system: It includes a variable-frequency water pump (6), a serpentine cooling water pipe arranged inside the concrete, and a plate heat exchanger (7) connected to the outlet of the cooling water pipe. The serpentine cooling water pipe is used to circulate cooling water to take away the hydration heat of the concrete, and the variable-frequency water pump (6) adjusts the water flow according to the instruction; Intelligent spraying subsystem: It includes an annularly partitioned electromagnetic nozzle (4) and an electric heating module (5). The electromagnetic nozzle (4) supports the switching between atomization and direct current dual modes, and the spraying water temperature is adjusted by the heat recovery system; Heat recovery circulation device: It includes a plate heat exchanger (7) and a phase change heat storage tank (8), and is used to store the waste heat of high-temperature cooling water in stages and provide preheated medium-low temperature water to the spraying system; Central control unit (9): Dynamically adjusts the cooling water flow, spraying mode and waste heat distribution strategy based on the temperature and humidity gradient data, and is built-in with a multi-objective optimization model. The final goal is to minimize the crack risk function R = αΔT + β(dT / dt) + γΔH, where ΔT is the maximum temperature difference inside and outside the concrete, ΔH is the internal humidity gradient, dT / dt is the maximum temperature difference change rate, and α, β, and γ are empirical coefficients.

2. The concrete regulation system integrating heat recovery, spraying and gradient control as claimed in claim 1, wherein The mode switching logic of the intelligent spraying subsystem is: When the internal humidity gradient > 15% RH / m or the internal temperature difference gradient ΔT / d > 15 °C / m, start atomization spraying (particle size ≤ 50 μm); When the core temperature > 60 °C and the humidity of the core layer < 80% RH, switch to direct current spraying (flow rate ≥ 10 L / min) and inject pre-cooled circulating water.

3. The concrete regulation system integrating heat recovery, spraying and gradient control according to claim 1, characterized in that, The hierarchical utilization strategy of the heat recovery circulation device includes: High-temperature cooling water (> 50 °C) is preferentially stored in the phase change heat storage tank (8), and the phase change material is paraffin or inorganic salt, and the phase change temperature is 40 - 60 °C; Medium-low temperature water (30 - 50 °C) is supplied to the spraying electric heating module (5) after secondary circulation through the plate heat exchanger (7).

4. The concrete regulation system integrating heat recovery, spraying and gradient control according to claim 1, characterized in that, The distributed optical fiber humidity sensor (10) adopts an optical fiber grating array, and a humidity sensitive unit is arranged every 0.5 m along the depth direction of the concrete. The humidity measurement range is 20 - 100% RH, and the accuracy is ±3% RH; The humidity sensitive unit is encapsulated in a porous ceramic sheath to directly contact the internal environment of the concrete.

5. The concrete regulation system integrating heat recovery, spraying and gradient control according to claim 1, characterized in that, The multi-objective optimization model built into the central control unit (9) takes the crack risk function: R = αΔT + β(dT / dt) + γΔH as the objective function, and realizes the coordinated control of the temperature and humidity gradient inside the concrete by adjusting the rotation speed of the variable-frequency water pump (6), the mode of the electromagnetic nozzle (4), and the heat distribution of the phase change heat storage tank (8).

6. The integrated concrete regulation system with heat recovery, spraying and gradient control according to claim 1, wherein The cooling water pipe is made of 304 stainless steel, with an inner diameter of 25 mm, and is arranged in a serpentine shape along the internal steel bar grid of the concrete. The transverse spacing is 0.8 - 1.2 m, and the longitudinal spacing is 0.6 - 1.0 m. The outlet end is connected to the plate heat exchanger (7) through a flange.

7. The concrete regulation system integrating heat recovery, spraying and gradient control according to claim 1, characterized in that, The electromagnetic spray head (4) is installed at a height of 0.3 - 0.5 m from the concrete surface, with an inclination angle of 15° - 30°, and is arranged in a grid partition with a size of 5 m × 5 m. The coverage area of a single spray head is 8 - 12 ㎡.

8. The concrete regulation system integrating heat recovery, spraying and gradient control as described in claim 1, characterized in that, The capacity of the phase change heat storage tank (8) is determined according to the volume of concrete, and 0.1 - 0.2 m 3 of heat storage volume is configured for each cubic meter of concrete, and a spiral flow guide plate is built in to improve the heat exchange efficiency.

9. A gradient temperature control method based on the system according to any one of claims 1-8, characterized in that, It includes the following steps: S1: Obtain the temperature - humidity gradient data inside the concrete through the distributed optical fiber temperature sensor (1) and the distributed optical fiber humidity sensor (10), and generate the surface temperature field in combination with the infrared thermal imager (2) to form a three - dimensional temperature - humidity distribution map; S2: When the temperature of the core layer exceeds 60 °C or the internal humidity gradient > 15% RH / m, the central control unit (9) starts the variable - frequency water pump (6). The cooling water is pre - cooled to 5 - 25 °C through the plate heat exchanger (7) and then injected into the internal pipe network of the concrete. At the same time, the heat of the high - temperature water above 50 °C at the outlet end is recovered to the phase - change heat storage tank (8); S3: Dynamically select the spraying mode according to the surface humidity sensor (3) and the internal humidity gradient data: start the atomizing spray (frequency ≥ once every 30 minutes) when the humidity gradient > 15% RH / m, and switch to the direct - current spray and add 1 - 3% curing agent when the humidity of the core layer < 75% RH.

10. The gradient temperature control method according to claim 9, characterized in that: The cooling water flow rate in S2 is dynamically adjusted according to the temperature difference gradient. When ΔT / d > 20 °C / m, the flow rate is set to 50 m 3 / h. When 10 °C / m ≤ ΔT / d ≤ 15 °C / m, the flow rate is reduced to 20 m 3 / h until the temperature difference gradient stabilizes within 10 °C / m.

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