Dam concrete temperature control anti-cracking system and method integrating monitoring

Abstract

The invention discloses a dam concrete temperature control anti-cracking system and method fused with monitoring, and relates to the technical field of hydraulic engineering construction.The system comprises a cooling pipe set arranged in dam concrete, and a heat exchange medium flows in the cooling pipe set and can conduct heat exchange and cooling on the dam concrete; the phase change energy pile module is arranged at the side slope of the downstream bank slope of the dam and can utilize underground latent heat for refrigeration; the heat pump assembly communicates with the cooling pipe set and the phase change energy pile module and can drive a heat exchange medium to circularly flow between the cooling pipe set and the phase change energy pile module. The monitoring module is arranged in dam concrete, optical fibers are pasted through notch grooves in steel bars, the temperature and strain in the dam concrete can be monitored, monitoring data are transmitted to the control end of the heat pump assembly, and the control end can dynamically adjust the temperature and flow speed of a water inlet and a water outlet of the heat pump assembly according to the monitoring data. According to the invention, the energy consumption in the dam concrete temperature control anti-cracking process is low, and no harm is caused to the environment.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy project construction and safety monitoring, and in particular to a dam concrete temperature control and crack prevention system and method for integrated monitoring. Background Art

[0002] In water conservancy projects and large-scale concrete construction, temperature fluctuations can pose a serious threat to concrete structures, causing through-hole cracks and, in turn, significantly compromising the integrity, durability, and impermeability of the dam concrete. To ensure concrete pour quality and maintain the safety and long-term stable operation of the dam, water cooling has become an indispensable temperature control and crack prevention method in large-scale concrete construction.

[0003] The principle of hydrocooling is to control the concrete temperature by introducing cooling water to dissipate heat from the poured concrete, thereby preventing cracks from forming. This process is designed to ensure that the concrete shrinks evenly during the hardening process, reducing internal temperature differences and thus reducing the risk of cracks.

[0004] Currently, hydropower station dam concrete construction typically uses mobile chiller stations with ammonia refrigeration technology to control the temperature and flow of cooling water to cool the concrete. Secondly, adding admixtures to the concrete mix can reduce the amount of cement in the concrete mix, thereby lowering the heat of hydration and minimizing the development of cracks. Another approach is to lower the temperature of concrete leaving the silo, either by pre-cooling concrete aggregate or mixing concrete with cold water during hot weather. Current refrigeration technology consumes relatively high energy, placing a significant burden on project operations. Furthermore, ammonia refrigeration can pose environmental risks.

[0005] Therefore, there is an urgent need to design a technical solution for temperature control and crack prevention of dam concrete that has low energy consumption and does not cause harm to the environment. Summary of the Invention

[0006] The purpose of the present invention is to provide a dam concrete temperature control and crack prevention system and method with integrated monitoring to solve the problems existing in the above-mentioned prior art, with low energy consumption in the process of dam concrete temperature control and crack prevention, and without causing harm to the environment.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a dam concrete temperature control and crack prevention system with integrated monitoring, comprising:

[0009] A cooling pipe group is arranged in the dam concrete, wherein a heat exchange medium flows in the cooling pipe group, which can exchange heat and cool the dam concrete;

[0010] Phase change energy pile modules, located on the slope of the downstream bank of the dam, can utilize underground latent heat for cooling;

[0011] A heat pump assembly is connected to the cooling tube group and the phase change energy pile module respectively, and can drive the heat exchange medium to circulate between the cooling tube group and the phase change energy pile module;

[0012] The monitoring module is installed in the dam concrete and can monitor the temperature and strain in the dam concrete and transmit the monitoring data to the control end of the heat pump component.

[0013] Preferably, the phase change energy pile module includes a plurality of phase change energy piles, and the phase change energy piles are made of a mixture of phase change material and concrete; a heat exchange structure connected to the heat pump assembly is provided inside the phase change energy pile.

[0014] Preferably, multiple heat exchange structures are connected in series in sequence, and the heat exchange structure in the phase change energy pile at one end is connected to the return heat pipe of the heat pump assembly, and the heat exchange structure in the phase change energy pile at the other end is connected to the delivery cold pipe of the heat pump assembly.

[0015] Preferably, the heat exchange structure includes a heat exchange tube, which is buried in the phase change energy pile along the axial direction, and the heat exchange tube is respectively provided with a medium inlet and a medium outlet.

[0016] Preferably, the cooling pipe group is horizontally arranged in the concrete of the strong constraint zone and the weak constraint zone of the dam foundation, and the concrete of the strong constraint zone and the weak constraint zone of the dam foundation is mixed with phase change material. The mixed phase change material can absorb part of the hydration heat of the concrete and reduce the degree of cracking of the dam concrete; the concrete of the strong constraint zone and the weak constraint zone of the dam foundation adopts phase change concrete, which can utilize the characteristics of phase change concrete that absorbs heat during the phase change process and the temperature generally does not change much, to reduce the maximum temperature of the concrete hydration process, thereby reducing the possibility of cracks in the concrete.

[0017] Preferably, the monitoring module includes monitoring steel bars, which are tied to the steel mesh in the corridor area or buried in the dam concrete; the monitoring steel bars are provided with temperature fiber optic sensors and strain fiber optic sensors, and the temperature fiber optic sensors and strain fiber optic sensors are respectively connected to the control ends of the heat pump components.

[0018] Preferably, a groove arranged along the axial direction of the monitoring steel bar is opened on the side wall of the monitoring steel bar, the strain fiber optic sensor is arranged in the groove, and the groove is filled with epoxy resin; a protective sleeve is attached to one side of the monitoring steel bar, and the temperature fiber optic sensor is passed through the protective sleeve.

[0019] Preferably, the heat exchange medium is water, and the heat pump assembly can transport the water cooled by heat exchange in the phase change energy pile module to the concrete aggregate silo to pre-cool the concrete aggregate.

[0020] The present invention also provides a dam concrete temperature control and crack prevention method with integrated monitoring, comprising the following steps:

[0021] A monitoring module is manufactured and installed in the concrete of the dam where the cooling pipe group is buried. The monitoring module transmits monitoring data to the control end of the heat pump assembly;

[0022] Based on the temperature and strain data of the monitoring module, the heat pump component is started to drive the heat exchange medium to circulate between the cooling pipe group and the phase change energy pile module at a set flow rate and flow velocity; the heat exchange medium flows into the cooling pipe group to absorb heat and heat up, and flows into the phase change energy pile module to release heat and cool down, realizing the temperature control process of the dam concrete.

[0023] Preferably, the monitoring module manufacturing method includes the following steps:

[0024] A groove is provided along the axial direction on one side of the monitoring steel bar;

[0025] Paste the strain fiber sensor into the groove of the monitoring steel bar, and then apply epoxy resin into the groove;

[0026] The temperature optical fiber sensor with a protective sleeve is fixed on the side wall of the monitored steel bar, and the temperature measuring point corresponds to the position of the strain measuring point.

[0027] Compared with the prior art, the present invention has achieved the following technical effects:

[0028] In the dam concrete temperature control and crack prevention method integrated with monitoring of the present invention, the concrete in the strong constraint zone and weak constraint zone of the dam foundation adopts phase change concrete. The characteristics of phase change concrete that absorbs heat during the phase change process and the temperature generally does not change much can be used to reduce the maximum temperature of the concrete during the hydration process, thereby reducing the possibility of concrete cracks. In addition, a cooling pipe group is provided in the phase change concrete to further cool it. The phase change energy pile in the phase change energy pile module is a slope support anti-slip pile for the downstream slope of the dam. The anti-slip pile not only serves as a supporting structure, but also can be used as a heat exchange structure by embedding heat exchange pipes inside it, without incurring additional pile pouring costs. The phase change energy pile can efficiently use underground shallow geothermal energy to cool the cooling water pipes in the concrete, pre-cool the concrete aggregate, and provide cold water for concrete mixing in hot seasons. Shallow geothermal energy is a clean and renewable energy source. Therefore, compared with the use of mobile cold water station ammonia refrigeration technology to cool river water, the phase change energy pile system is cheaper and more environmentally friendly. The integrated monitoring module in the solution of the present invention can realize integrated monitoring of strain and temperature, and cooperate with the energy pile system to form a three-in-one system of "energy pile cooling-intelligent monitoring-phase change temperature control", which is used for temperature control and crack prevention in dam concrete construction. The flow rate, flow velocity and inlet and outlet temperatures of the cooling pipe group can be adjusted in time according to the monitoring results (temperature and strain) of the monitoring module. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic diagram of the layout of a dam concrete temperature control and crack prevention system for integrated monitoring in one or some embodiments of the present invention;

[0031] Figure 2 A schematic cross-sectional view of a dam A section of a dam concrete temperature control and crack prevention system integrated with monitoring in one or some embodiments of the present invention;

[0032] Figure 3 A schematic diagram of a cooling pipe group of a dam concrete temperature control and crack prevention system integrated with monitoring in one or some embodiments of the present invention;

[0033] Figure 4 A schematic diagram of monitoring steel bars in a dam concrete temperature control and crack prevention system integrated with monitoring in one or some embodiments of the present invention;

[0034] Figure 5 A schematic diagram of a radial cross-section of monitoring steel bars in a dam concrete temperature control and crack prevention system integrated with monitoring in one or some embodiments of the present invention;

[0035] Figure 6 A schematic diagram of the arrangement of the phase change energy pile module and the heat pump assembly of the dam concrete temperature control and crack prevention system integrated with monitoring in one or some embodiments of the present invention;

[0036] Figure 7 A schematic diagram of the internal structure of a phase change energy pile in one or some embodiments of the present invention;

[0037] Figure 8 A schematic diagram of the working process of a dam concrete temperature control and crack prevention system integrating monitoring in one or some embodiments of the present invention;

[0038] Figure 9 Schematic diagram of the working process of the dam concrete temperature control and crack prevention system with integrated monitoring under extreme working conditions in one or some embodiments of the present invention.

[0039] In the figure: 1-phase change energy pile, 101-parallel double U-shaped heat exchange tube, 2-heat pump assembly, 3-cooling pipe group, 4-aggregate silo, 5-monitoring steel bar, 501-groove, 502-temperature fiber optic sensor, 503-strain fiber optic sensor, 6-weakly constrained area of ​​dam foundation, 7-strongly constrained area of ​​dam foundation, 8-phase change material, 9-unconstrained area, 10-slope, 11-dam. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide a dam concrete temperature control and crack prevention system and method with integrated monitoring to solve the problems existing in the above-mentioned prior art, with low energy consumption in the process of dam concrete temperature control and crack prevention, and without causing harm to the environment.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] At present, the concrete construction of hydropower station dams usually adopts mobile chiller station ammonia refrigeration technology to control the temperature and flow of cooling water to achieve the cooling of concrete. The process consumes a lot of energy and ammonia refrigeration is easy to cause damage to the environment. In order to solve this problem, the present invention provides a dam concrete temperature control and crack prevention system with integrated monitoring, such as Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, it includes a cooling pipe group 3 arranged in the dam concrete, and a heat exchange medium flows in the cooling pipe group 3, which can heat exchange and cool the dam concrete; combined with Figure 1The dam 11 is set on the bedrock surface, with one side of the dam 11 being upstream and the other side being downstream. The phase change energy pile module is set at the slope 10 of the downstream bank of the dam 11, which can use the underground latent heat to cool the heat exchange medium. A horse path is provided on the inner side of the slope 10. The phase change energy piles in the phase change energy pile module are anti-slip piles for supporting the slope of the downstream bank of the dam. The anti-slip piles can not only serve as supporting structures, but also can be used as heat exchange structures by embedding heat exchange pipes inside them, without generating additional pile pouring costs. The heat pump assembly 2 is respectively connected to the cooling pipe group 3 and the phase change energy pile module, which can It is able to drive the heat exchange medium to circulate between the cooling pipe group 3 and the phase change energy pile module; thereby, the low-temperature heat exchange medium in the cooling pipe group 3 exchanges heat with the dam concrete to increase its temperature, causing the dam concrete temperature to decrease. The heated heat exchange medium is driven into the phase change energy pile module through the heat pump assembly 2, and exchanges heat with the low-temperature soil where the phase change energy pile module is located to cool it down. The cooled heat exchange medium then flows back into the cooling pipe group 3 and circulates in sequence to achieve cooling of the dam concrete. During this process, underground shallow heat is used to cool the cooling water pipes in the concrete, resulting in low energy consumption. The lower part of the dam 11 in this embodiment is the dam foundation strong constraint area 7, followed by the dam foundation weak constraint area 6 and the non-constraint area 9 upwards.

[0044] In order to achieve precise temperature control of the dam concrete, a monitoring module is provided in this embodiment. The monitoring module includes a temperature fiber optic sensor 502 and a strain fiber optic sensor 503 provided in the dam concrete. The monitoring module can monitor the temperature and strain in the dam concrete and transmit the monitoring data to the control end of the heat pump component 2. The heat pump component 2 and its control end are both mature structures. The heat pump component 2 mainly includes a heat pump as a heat exchange medium power and a delivery pipeline, and its control end can use a computer and a control panel to realize the control function of opening and closing the heat pump and the delivery speed and flow size of the delivery pipeline.

[0045] In one embodiment, the phase change energy pile module includes a plurality of phase change energy piles 1, such as Figure 7As shown, the phase change energy pile 1 is provided with parallel double U-shaped heat exchange tubes 101, which are arranged in a staggered manner and have a water inlet and a water outlet on the top. The phase change energy pile 1 replaces the complex heat exchange pipe network arranged in the soil with a pipe buried in the pile, which not only saves construction cost and underground space, but also reduces the corrosion of the heat exchange pipe, thereby extending the service life of the ground source heat pump system. This embodiment is further improved on the basis of the energy pile and designed as a phase change energy pile 1. The phase change energy pile 1 is made of a mixture of phase change material 8 and concrete. The specific composition, phase change temperature and structure of the phase change material 8 are not limited. Organic phase change material or inorganic phase change material can be used; adding phase change material 8 to a traditional energy pile to form a phase change energy pile 1 can effectively increase the heat storage / cold storage capacity of the energy pile and improve the energy density, reduce the temperature variation of the pile body, reduce the impact of the temperature load on the pile body and reduce the heat diffusion range of the energy pile, and at the same time improve the heat exchange performance of the energy pile and improve the structural safety of the energy pile. The phase change energy pile 1 is internally provided with a heat exchange structure connected to the heat pump assembly 2. In order to improve applicability, the size and shape of the phase change energy pile 1 are not restricted, and its cross-section can be designed to be circular, square, or irregular polygonal, etc. The phase change energy pile 1 can be used as an anti-slip pile to support the slope 10 of the downstream bank of the dam 11. The anti-slip pile can not only serve as a supporting structure, but also has a heat exchange structure embedded in it, without incurring additional pile pouring costs, thus achieving multiple uses of one pile. The phase change energy pile 1 can efficiently utilize underground shallow geothermal energy to cool the cooling water pipes in the concrete, pre-cool the concrete aggregate, and provide cold water for concrete mixing in hot seasons. Shallow geothermal energy is a clean and renewable energy source. Therefore, compared with the use of mobile cold water station ammonia refrigeration technology to cool river water, the phase change energy pile 1 is cheaper and more environmentally friendly, and does not harm the environment.

[0046] Multiple heat exchange structures are connected in series in sequence, and the heat exchange structure in the phase change energy pile 1 at one end is connected to the return heat pipe of the heat pump assembly 2, and the heat exchange structure in the phase change energy pile 1 at the other end is connected to the delivery cold pipe of the heat pump assembly 2. There is no specific limitation on the heat exchange structure. In one embodiment, the heat exchange structure adopts parallel double U-shaped heat exchange tubes. In other embodiments, a single U-shaped heat exchange tube or a spiral heat exchange tube can be used, which is buried in the phase change energy pile 1 along the axial direction with the opening facing upward, so that the medium inlet and medium outlet of the heat exchange structure are both located at the top of the phase change energy pile 1, which is convenient for serial connection with the heat exchange structures in other phase change energy piles 1, and also convenient for communication with the heat pump assembly 2.

[0047] In order to further improve the temperature control effect, the cooling pipe group 3 of this embodiment uses cooling pipes in a spiral, serpentine, or other shape, and is arranged horizontally in the concrete of the dam foundation strong constraint zone 7 and the dam foundation weak constraint zone 6. The concrete of the dam foundation strong constraint zone 7 and the dam foundation weak constraint zone 6 is mixed with a phase change material 8. The method of adding the phase change material 8 to the phase change concrete of the dam foundation strong constraint zone 7 and the dam foundation weak constraint zone 6 is not fixed. The phase change material 8 can be combined with the concrete in the form of microcapsules, steel balls, and adsorption. The reason for using phase change concrete in the dam foundation strong constraint zone 7 and the dam foundation weak constraint zone 6 is that the maximum allowable temperature requirements of the foundation strong constraint zone and the weak constraint zone are more stringent than those of the non-constrained zone, and the maximum allowable temperature is relatively low. The use of phase change concrete can effectively reduce the maximum temperature of the concrete, thereby reducing concrete cracking.

[0048] To achieve more precise temperature control while minimizing disturbance to the dam's concrete structure, in one embodiment, the monitoring module utilizes a monitoring rebar 5 structure. The monitoring rebar 5 is tied to the corridor's steel mesh or embedded within the dam's concrete. A temperature fiber optic sensor 502 and a strain fiber optic sensor 503 are attached to the monitoring rebar 5. These sensors are connected to an external junction box, the outlets of which are connected to the control terminal of the heat pump assembly 2. Both the temperature fiber optic sensor 502 and the strain fiber optic sensor 503 in this embodiment are optical fiber sensors. Compared to traditional temperature and strain monitoring methods, such as thermocouples, thermistor temperature fiber optic sensors 502, or vibrating wire strain gauges, optical fiber sensors offer significant advantages in dam 11 safety monitoring. Traditional sensors are susceptible to lightning strikes, electromagnetic interference, and environmental corrosion, resulting in reduced data acquisition stability. Optical fiber sensors, on the other hand, not only offer resistance to electromagnetic interference, corrosion resistance, and long transmission distances, but also enable distributed monitoring, accurately acquiring temperature and strain information at varying elevations and dam wheelbases, improving the reliability and durability of the monitoring system. This embodiment uses FBG strain fiber and temperature fiber. FBG strain fiber is a fiber Bragg grating. In other embodiments, distributed (Brillouin) fiber or Raman scattering fiber can also be used for strain monitoring. The temperature fiber can not only monitor concrete temperature changes but also be used for strain fiber temperature compensation.

[0049] In one embodiment, in order to better arrange the sensors, it is proposed to produce the monitoring steel bar 5 by laser grooving, embed the optical fiber sensor into the groove 501 of the monitoring steel bar 5, and then coat the groove 501 with epoxy resin as a protective layer. The thickness of the protective layer is ≥3mm. While ensuring that the optical fiber sensor is protected from construction damage, it achieves precise coupling of monitoring data and structural response, further improving the engineering applicability and long-term stability of the monitoring system. Specifically, in this embodiment, a groove 501 is opened on the side wall of the monitoring steel bar 5 and arranged along the axial direction of the monitoring steel bar 5. The strain optical fiber sensor 503 is set in the groove 501, and then the groove 501 is filled with epoxy resin as a protective layer; a protective sleeve is attached to the side of the monitoring steel bar 5 at a position corresponding to the strain optical fiber sensor 503, and a temperature optical fiber sensor 502 is inserted into the protective sleeve. The present invention monitors the strain and temperature of the steel bar 5 in an integrated monitoring structure, and cooperates with the phase change energy pile module and the phase change material 8 in the dam concrete to form a three-in-one dam concrete construction temperature control and crack prevention scheme, which includes phase change energy pile 1 for cooling - monitoring module for monitoring temperature and strain - and dam concrete phase change temperature control. The scheme can timely adjust the flow rate and flow velocity of the heat exchange medium and the inlet and outlet temperatures of the cooling water pipe according to the monitoring results (temperature and strain) of the steel bar 5, thereby enhancing the temperature control and crack prevention effect of the dam concrete construction.

[0050] In order to further reduce energy consumption and lower costs, in one embodiment, the heat exchange medium is water, and nearby river water can be used. The heat pump component 2 can transport the water after heat exchange and cooling in the phase change energy pile module to the concrete aggregate silo 4 in the nearby area to pre-cool the concrete aggregate.

[0051] The present invention also provides a dam concrete temperature control and crack prevention method with integrated monitoring, comprising the following steps:

[0052] A monitoring module is made and set in the dam concrete where the cooling pipe group 3 is buried. The monitoring module transmits the monitoring data to the control end of the heat pump component 2; the high-temperature river water is pumped into the heat pump component 2 through a water pump; based on the temperature and strain data of the monitoring module, the heat pump component 2 is started to drive the river water to circulate between the cooling pipe group 3 and the phase change energy pile module at a set flow rate and flow velocity; the high-temperature river water in the heat pump flows into the parallel double U-shaped heat exchange tubes of the phase change energy pile 1 through the heat exchange tubes, and the high-temperature river water in the parallel double U-shaped heat exchange tubes exchanges heat with the phase change energy pile 1 and the soil around the pile (the underground soil is in a constant temperature state of 10-15°C all year round), and during this heat exchange process, the phase change material 8 in the phase change energy pile 1 undergoes phase change, releasing a large amount of latent heat, which can further reduce the temperature of the river water. The river water after the temperature is reduced flows into other phase change energy piles 1 in series in turn to continue heat exchange and cooling. Finally, the water flows back to the heat pump through the medium outlet of the final phase-change energy pile 1. The heat pump then pumps the chilled river water into cooling water pipes within the dam concrete, cooling the concrete. Simultaneously, the heat pump can also pump the chilled river water into the concrete aggregate silo 4 to pre-cool the concrete aggregate or provide cooler river water for concrete mixing.

[0053] In the above scheme, the monitoring module manufacturing method includes the following steps:

[0054] A groove 501 is cut axially along one side of the monitoring rebar 5. Specifically, a laser notcher is used to create the groove, with a cross-sectional dimension of 3 mm wide and 3 mm deep. The strain fiber sensor is affixed to the groove 501 using adhesive, and then epoxy resin is applied to the groove. A temperature fiber with a protective sleeve is then affixed to the monitoring rebar 5, with the temperature measurement points aligned with the strain measurement points. Finally, the prepared monitoring rebar 5 is installed and tied to the corridor's steel mesh or directly embedded in the concrete in the pouring bin to monitor concrete strain and temperature changes.

[0055] like Figure 8 As shown, in one embodiment, the dam concrete temperature control and crack prevention system of the present invention with integrated monitoring works as follows:

[0056] After the dam concrete is poured, the phase change material within the concrete undergoes a phase change. The monitoring module acquires the dam concrete temperature and strain and determines whether the concrete monitoring data exceeds the safe temperature range or strain limit. If it does, no adjustments are required and monitoring continues. If it does, the module acquires the current temperature and flow rate of the dam's cooling water pipes, as well as the current temperature and flow rate at the phase change energy source inlet and outlet. The temperature control analysis module then develops an adjustment strategy, such as lowering the water temperature to reflect rising concrete temperatures in high-temperature areas and reducing the flow rate in low-temperature areas. The phase change energy source system adjusts the number of energy sources connected in series and the flow rate of the circulating fluid. The heat pump control module's heat pump component dynamically adjusts the inlet temperature and flow rate of the cooling water pipes in different areas of the dam concrete.

[0057] The specific plan for the above work process includes:

[0058] Concrete pouring and phase change activation: Control the temperature of large concrete entering the mold (phase change energy piles provide cold water to pre-cool the aggregate before mixing the concrete). After the dam concrete is poured, the phase change material mixed inside triggers endothermic phase change when the concrete temperature rises to the phase change temperature of the phase change material, thereby buffering the temperature rise rate.

[0059] Dam concrete temperature and strain monitoring: The system activates the monitoring module to obtain real-time temperature and strain data of the dam concrete. The monitoring data is collected through sensors (such as temperature fiber optics and strain fiber optics).

[0060] Determine safety range: The system automatically determines whether the current monitoring data exceeds the safety threshold based on the preset safety temperature range and strain limit:

[0061] (a) Dam Concrete Temperature Control Indicators: The maximum allowable temperature for each part of the mass concrete is divided into different zones based on the long side dimension (L) of the cast block and its height from the foundation surface: Strongly Constrained Zone (0-0.2L): When L < 30m, the maximum allowable temperature is 39.0°C; when 30m ≤ L < 70m, the maximum allowable temperature is 36.0°C. Weakly Constrained Zone (0.2L-0.4L): When L < 30m, the maximum allowable temperature is 41.0°C; when 30m ≤ L < 70m, the maximum allowable temperature is 38.0°C. Free Zone (>0.4L): When L < 30m, the maximum allowable temperature is 43.0°C; when 30m ≤ L < 70m, the maximum allowable temperature is 41.0°C. The temperature difference between the inside and outside of the dam concrete should not exceed 15°C.

[0062] (b) Dam concrete strain control indicator: Control the tensile strain caused by temperature deformation to prevent it from exceeding the ultimate tensile capacity of the concrete. Calculate the tensile stress based on the strain value and compare it with 80% of the design value. Secondly, control the temperature-controlled cracking safety factor. If both the concrete temperature and strain are within the safe range, the system does not require any adjustments and continues monitoring.

[0063] If the temperature or strain exceeds the safe range, proceed to the next step of the adjustment procedure.

[0064] Temperature Control Analysis and Adjustment Strategy Development: If monitoring data exceeds the safe range, the temperature control analysis module conducts in-depth analysis and formulates an adjustment strategy based on the following information: the current temperature and flow rate of the dam's cooling water pipes; the current temperature and flow rate of the phase change energy pile inlet and outlet. Combined with the dam concrete's temperature control indicators, the temperature rise curve in high-temperature areas is predicted in advance. Through analysis, the temperature control analysis module generates specific adjustment strategies and implements appropriate temperature control measures for dam concrete in different areas: High-temperature areas: If the concrete temperature is too high, the system will adjust the cooling water pipe inlet temperature and reduce the water flow rate according to the strategy to help quickly reduce the temperature in the high-temperature area. Low-temperature areas: If the concrete temperature is too low, the system will adjust the water flow rate to a lower level to prevent overcooling.

[0065] Phase Change Energy Pile Adjustment: The phase change energy pile system adjusts the number of series energy piles and the flow rate of the circulating fluid based on the current temperature control strategy to optimize temperature control. The temperature and flow rate of each energy pile are finely adjusted according to the actual needs of the dam.

[0066] Heat pump regulation: The heat pump component will dynamically adjust the temperature and flow of the cooling water pipe inlet according to the temperature control requirements of different areas of the dam to ensure that the temperature in each area is controlled within the optimal range.

[0067] Entering the next cycle: After completing the current adjustment, the system will enter the next cycle and continue to monitor the changes in concrete temperature and strain to ensure that the dam concrete is always within a safe temperature and strain range.

[0068] like Figure 9 As shown, in another embodiment, the working process of the dam concrete temperature control and crack prevention system of the present invention under extreme working conditions is as follows:

[0069] After the dam concrete is poured, the phase change material within the concrete undergoes a phase change. Climate temperature data is collected, and extreme high-temperature conditions are identified. The monitoring module acquires the dam concrete temperature and strain, the current temperature and flow rate of the dam's cooling water pipes, and the current temperature and flow rate at the phase-change energy pile inlet and outlet. The temperature control analysis module, based on the extreme temperature, formulates an adjustment strategy, such as lowering the water temperature to reflect rising concrete in high-temperature areas and reducing the flow rate in low-temperature areas. The phase-change energy pile system adjusts the number of series-connected energy piles and the flow rate of the circulating fluid. The heat pump regulation module dynamically adjusts the inlet temperature and flow rate of the cooling water pipes in different areas of the dam concrete. A backup cooling tower is activated, and the data collection frequency is increased. The monitoring module repeats the steps to acquire the dam concrete temperature and strain, as well as the subsequent steps.

[0070] The specific plan for the above work process includes:

[0071] Concrete pouring and phase change activation: Control the temperature of concrete entering the mold (phase change energy piles provide cold water to pre-cool the aggregate before mixing the concrete). After the dam concrete is poured, the phase change material mixed inside triggers an endothermic phase change when the concrete temperature rises to the phase change temperature of the phase change material, thereby buffering the temperature rise rate.

[0072] Extreme high temperature identification and graded warning:

[0073] Judgment conditions: Level 1 warning: ambient temperature ≥ 38℃ and concrete temperature rise rate > 0.3℃ / h; Level 2 warning: ambient temperature ≥ 42℃ or core area temperature > 45℃, and lasts for more than 2 hours.

[0074] The monitoring module obtains the temperature and strain of the dam concrete.

[0075] Temperature Control Analysis and Adjustment Strategy Development: If monitoring data exceeds the safe range, the temperature control analysis module conducts in-depth analysis and develops an adjustment strategy based on the following information: the current temperature and flow rate of the dam's cooling water pipes; the current temperature and flow rate of the phase change energy pile inlet and outlet. The temperature control analysis module dynamically evaluates changes in external and internal dam temperatures, predicting temperature rise curves in high-temperature areas in advance and making corresponding adjustments. Through analysis, the temperature control analysis module generates specific adjustment strategies and implements appropriate temperature control measures for dam concrete in different areas: High-temperature areas: If the concrete temperature is too high, the system will adjust the cooling water pipe inlet temperature and reduce the water flow rate according to the strategy to help quickly reduce the temperature in the high-temperature area. Low-temperature areas: If the concrete temperature is too low, the system will adjust the water flow rate to a lower level to avoid overcooling.

[0076] Phase Change Energy Pile Adjustment: The phase change energy pile system adjusts the number of series energy piles and the flow rate of circulating fluid based on the current temperature control strategy to optimize temperature control. The temperature and flow rate of each energy pile are finely tuned to the actual needs of different areas of the dam.

[0077] Coordinated regulation of the heat pump system: In extremely hot weather, the regulation of the heat pump system needs to be more flexible, and it may also face the situation of overload of cooling demand. At this time, the backup cooling tower should be started.

[0078] Cooling water temperature regulation: By adjusting the outlet water temperature of the heat pump system, ensure that the water temperature entering the cooling water pipe is always maintained within the appropriate temperature control range to avoid external high temperature affecting the cooling effect.

[0079] High-efficiency cooling mode: The heat pump system will enable high-efficiency cooling mode, giving priority to providing cooling support to areas with higher temperatures.

[0080] Start the backup cooling tower: The backup cooling tower is used to meet the cooling needs of extreme high temperatures.

[0081] Encrypted monitoring: Increase the frequency of data collection. In extremely hot weather, the system needs to strengthen real-time monitoring of temperature, strain and other data.

[0082] Entering the next cycle: After completing the adjustment, the system will continue to monitor the temperature and strain changes of the concrete. Each temperature control adjustment cycle should be shortened according to the changes in extreme high temperature weather to ensure that the concrete temperature is always within the safe range to avoid cracking.

[0083] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A dam concrete temperature control and crack prevention system with integrated monitoring, characterized by: include: A cooling pipe group is arranged in the dam concrete, wherein a heat exchange medium flows in the cooling pipe group, which can exchange heat and cool the dam concrete; Phase change energy pile modules, located on the slope of the downstream bank of the dam, can utilize underground latent heat for cooling; A heat pump assembly is connected to the cooling tube group and the phase change energy pile module respectively, and can drive the heat exchange medium to circulate between the cooling tube group and the phase change energy pile module; The monitoring module is installed in the dam concrete and can monitor the temperature and strain in the dam concrete and transmit the monitoring data to the control end of the heat pump component.

2. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 1 is characterized by: The phase change energy pile module includes a plurality of phase change energy piles, and the phase change energy piles are made of a mixture of phase change material and concrete; a heat exchange structure connected to the heat pump assembly is provided inside the phase change energy pile.

3. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 2 is characterized by: The multiple heat exchange structures are connected in series in sequence, and the heat exchange structure in the phase change energy pile at one end is connected to the return heat pipe of the heat pump assembly, and the heat exchange structure in the phase change energy pile at the other end is connected to the delivery cold pipe of the heat pump assembly.

4. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 2 is characterized by: The heat exchange structure includes a heat exchange tube, which is buried in the phase change energy pile along the axial direction. The heat exchange tube is respectively provided with a medium inlet and a medium outlet.

5. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 1 is characterized by: The cooling pipe group is horizontally arranged in the concrete of the strong constraint area and the weak constraint area of ​​the dam foundation, and the concrete of the strong constraint area and the weak constraint area of ​​the dam foundation is mixed with phase change material. The mixed phase change material can absorb part of the concrete hydration heat and reduce the degree of cracking of the dam concrete.

6. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 1 is characterized by: The monitoring module includes monitoring steel bars, which are tied to the steel mesh in the corridor area or buried in the dam concrete; the monitoring steel bars are provided with temperature fiber optic sensors and strain fiber optic sensors, which are respectively connected to the control end of the heat pump assembly.

7. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 6 is characterized by: A groove arranged along the axial direction of the monitoring steel bar is opened on the side wall of the monitoring steel bar, the strain fiber optic sensor is arranged in the groove, and the groove is filled with epoxy resin to protect the strain fiber optic sensor; a protective sleeve is attached to one side of the monitoring steel bar, and the temperature fiber optic sensor is passed through the protective sleeve.

8. The dam concrete temperature control and crack prevention system with integrated monitoring according to claim 1 is characterized by: The heat exchange medium is water, and the heat pump assembly can transport the water cooled after heat exchange in the phase change energy pile module to the concrete aggregate silo to pre-cool the concrete aggregate.

9. A dam concrete temperature control and crack prevention method with integrated monitoring, characterized by: The steps include: A monitoring module is manufactured and placed in the phase-change concrete of the dam where the cooling pipe group is buried. The monitoring module transmits monitoring data to the control end of the heat pump assembly; Based on the temperature and strain data of the monitoring module, the heat pump component is started to drive the heat exchange medium to circulate between the cooling pipe group and the phase change energy pile module at a set flow rate and flow velocity; the heat exchange medium flows into the cooling pipe group to absorb heat and heat up, and flows into the phase change energy pile module to release heat and cool down, realizing the temperature control process of the dam concrete.

10. The dam concrete temperature control and crack prevention method with integrated monitoring according to claim 9 is characterized in that: The monitoring module manufacturing method includes the following steps: A groove is provided along the axial direction on one side of the monitoring steel bar; Paste the strain fiber sensor into the groove of the monitoring steel bar, and then apply epoxy resin into the groove; The temperature optical fiber sensor with a protective sleeve is fixed on the side wall of the monitored steel bar, and the temperature measuring point corresponds to the position of the strain measuring point.

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