Ecological dredging mud temperature and pressure coupling heat phase change type dewatering and drying system and method

Abstract

The application discloses an ecological dredged sediment temperature-pressure coupling thermal phase change type dewatering and drying system and method, and belongs to the technical field of ecological dredged sediment dewatering and drying, which comprises the following steps: obtaining guiding parameters of target sediment; first, extracting sample sediment from the target sediment, arranging data acquisition modules and dewatering and drying components in the sample sediment, then performing a temperature-pressure coupling thermal phase change type dewatering and drying experiment on the sample sediment, finally selecting experimental data meeting target requirements as the guiding parameters through analysis of the experimental data; arranging data acquisition modules and dewatering and drying components in the target sediment; using the dewatering and drying components to perform temperature-pressure coupling thermal phase change type dewatering and drying treatment on the target sediment, collecting state parameters of the target sediment in real time or at fixed time intervals during the treatment; comparing the state parameters with the guiding parameters, selecting the guiding parameter with the least difference from the guiding parameters, and adjusting the working condition parameters of the dewatering and drying components by using the guiding parameter.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ecological dredged sediment dewatering and drying, and particularly relates to a warm-pressure coupling thermal phase change type dewatering and drying system and method for ecological dredged sediment. BACKGROUND

[0002] It is known that the main components of ecological dredged sediment include fine and sticky particles, silty particles, organic matter, a large amount of water and gas, and the ecological dredged sediment has characteristics such as high water content, large void ratio, poor permeability and strong compressibility. In recent years, the state has vigorously carried out ecological management projects of rivers, lakes and reservoirs, and a large amount of dredged sediment has been produced. The disposal and treatment of the sediment is a major problem in dredging and treatment projects, and the high water content in the sediment is a key factor restricting its resource utilization.

[0003] At present, the traditional drainage consolidation technology mainly includes vacuum preloading, electro-osmotic vacuum preloading, combined load and vacuum preloading and mechanical pressure filtration. The above technologies all apply external force or electrochemical action to carry out drainage consolidation without changing the state of water in the sediment. However, as the drainage consolidation proceeds, the void ratio continuously decreases, the permeability becomes poor, the drainage consolidation efficiency decreases, and the drainage consolidation period is long and the effect is poor. Therefore, the thermal phase change technology can be used to change the phase state of water in the sediment, improve the permeability of water in the sediment, and many scholars have studied the influence of temperature increase and heating technology on sediment dewatering and consolidation in related papers. For example, the documents (Influence of heating on vacuum preloading drainage consolidation of soft soil sediment, Hydrogeology and Engineering Geology, 2020, 47(1), 62-68; Field test study on vacuum preloading of sludge based on temperature increase and heating technology, Hydrogeology and Engineering Geology, 2022, 49(4), 125-134) all study the influence of temperature increase and heating on the drainage consolidation of sludge, and believe that the higher the temperature, the better the dewatering and drying effect of the sediment.

[0004] However, it is found in actual operation that too high a temperature will cause the sediment to rapidly dewater and harden, and then form a clay layer that blocks the conduction of temperature and reduces the seepage path of water, resulting in poor dewatering and drying effect in a large range. At the same time, too high a temperature requires large energy consumption, high cost, poor stability and safety. SUMMARY

[0005] In order to solve the technical problems in the prior art, the present application provides a warm-pressure coupling thermal phase change type dewatering and drying system and method for ecological dredged sediment, which obtains guiding parameters for efficiently realizing the warm-pressure coupling thermal phase change type dewatering and drying process through warm-pressure coupling thermal phase change type dewatering and drying experiment analysis of sample sediment.

[0006] The first object of the present application is to provide a warm-pressure coupling thermal phase change type dewatering and drying system for ecological dredged sediment, which comprises:

[0007] The first acquisition unit acquires the target sediment;

[0008] The second acquisition unit acquires the guiding parameters of the target sediment: first, a sample sediment is extracted from the target sediment, a data acquisition module and a dewatering and drying component are arranged in the sample sediment, then a temperature and pressure coupled thermal phase change type dewatering and drying experiment is performed on the sample sediment, during the experiment, experimental data are collected by the data acquisition module, the experimental data include the temperature, the permeability coefficient, the degree of consolidation, the water discharge rate, the settlement rate and the pore water pressure change rate of the sample sediment, finally, through analysis of the experimental data, the experimental data meeting the target requirements are selected as the guiding parameters; the dewatering and drying component includes a heating element, a drainage assembly and a vacuum pumping device; wherein:

[0009] The analysis of the experimental data includes:

[0010] Analysis I: through analysis of the water discharge rate, the settlement rate, the pore water pressure change rate and the temperature of the sample sediment, the phase change point temperature of water in the sample sediment under different vacuum degrees is obtained; the specific analysis process under each vacuum degree is as follows:

[0011] When the vacuum degree is determined, the sample sediment is gradually heated, the temperature, the water discharge rate, the settlement rate and the pore water pressure change rate in the heating process are obtained, and finally the temperature T w at the water discharge rate mutation point, the temperature T s at the settlement rate mutation point and the temperature T v at the pore water pressure change rate mutation point are extracted, and the maximum value of T v , T w and T s is selected as the phase change point temperature T;

[0012] Analysis II: the most suitable drainage temperature Tz of the sample sediment under different degrees of consolidation and the permeability coefficient k max under the most suitable drainage temperature Tz under different vacuum degrees are obtained.

[0013] The arrangement unit: the data acquisition module and the dewatering and drying component are arranged in the target sediment;

[0014] The information acquisition unit: the target sediment is subjected to temperature and pressure coupled thermal phase change type dewatering and drying treatment by using the dewatering and drying component, and the state parameters of the target sediment are collected in real time or at regular intervals during the treatment;

[0015] The control unit: the state parameters are compared with the guiding parameters, the guiding parameter with the smallest difference is selected from the guiding parameters, and the working condition parameters of the dewatering and drying component are adjusted by using the guiding parameter; the guiding parameters include the heating temperature and the vacuum degree of the target sediment; the heating temperature is not greater than T+5.

[0016] Preferably, the acquisition process of the first acquisition unit is:

[0017] S101, determining a target area of the ecological dredged sediment;

[0018] S102, establishing an isolation zone around the target sediment in the target area, or transferring the target sediment in the target area to an isolation zone;

[0019] S103, setting a covering sealing film on the target area.

[0020] Preferably, the acquisition process of the second acquisition unit is:

[0021] S201, extracting a single or M portions of sample sediment from the same or different positions of the target sediment, M being a natural number greater than 1, and arranging a data collection module and a dehydration and drying unit in each portion of sample sediment;

[0022] S202, performing a temperature-pressure coupling thermal phase change dehydration and drying experiment on each portion of sample sediment, and collecting experimental data in real time or at regular intervals during the experiment;

[0023] S203, analyzing each portion of experimental data, and selecting experimental data meeting the target requirements as the guiding parameters of the target sediment in the sampling point area corresponding to the experimental data.

[0024] Preferably, the method for obtaining the phase transition temperature T is:

[0025] Step one: Put the sample sediment into a sealed container and perform vacuum extraction;

[0026] Step two: When the average water discharge rate is less than 10 g / h within 4-6 consecutive hours, gradually increase the temperature of the sample sediment by 5-10°C each time; during the temperature increasing process:

[0027] Measure the water discharge rate of the sample sediment, and when the water discharge rate of the sample sediment instantaneously increases by more than 10 times, record the temperature at this time as T w ;

[0028] Measure the sedimentation rate of the sample sediment, and when the sedimentation rate of the sample sediment instantaneously increases by more than 10 times, record the temperature at this time as T s ;

[0029] Measure the change rate of pore water pressure, and when the change rate of pore water pressure instantaneously increases by more than 10 times, record the temperature at this time as T v ;

[0030] Step three: Select the maximum value of T w , T s and T v as the phase transition temperature T.

[0031] Preferably, the negative pressure condition is 80 KPA, and the experiment of consolidation degree includes:

[0032] S2-1, test the permeability coefficient k of the sample bottom mud under the negative pressure condition within the temperature interval i ; the temperature interval is T i (20, 60);

[0033] S2-2, perform a quartic polynomial fitting on the sample bottom mud temperature t i and the permeability coefficient k i ;

[0034] The expression of the curve after the quartic polynomial fitting is:

[0035] k i =a0+a1t i +a2t i 2 +a3t i 3 +a4t i 4 ;

[0036] In the formula, a0, a1, a2, a3, and a4 are fitting coefficients;

[0037] S2-3, obtain the optimal drainage temperature T z and the optimal permeability coefficient k max under the optimal drainage temperature Tz through the curve;

[0038] Obtain the second derivative of the curve:

[0039] k”=2a2+6a3t i +12a4t i 2 ;

[0040] In the formula, t i is the temperature of the sample bottom mud;

[0041] Let k”=0; then the optimal drainage temperature T z is:

[0042]

[0043] The optimal permeability coefficient k max corresponding to the optimal drainage temperature is:

[0044] k max =a0+a1T z +a2T z 2 +a3T z 3 +a3Tz 4 ;

[0045] S2-4, under stable pressure conditions, determine the permeability coefficient of the sample bottom mud under different consolidation states;

[0046] Using a nonlinear fitting method to establish the consolidation degree U t In the lifting process, the optimal permeability coefficient k max The optimal drainage temperature T z The change characteristic curve;

[0047] Under different consolidation degrees U t , repeat S2-1-S2-3, and obtain the optimal drainage temperature T max The optimal permeability coefficient k z of the sample bottom mud under different consolidation states;

[0048] S2-5, in the consolidation degree U t growth process, establish the corresponding relationship between the consolidation degree U t and the optimal drainage temperature T z .

[0049] Preferably, the specific steps of the quartic polynomial fitting are: obtaining the quartic polynomial optimal solution by using the loss function Loss minimization, or iteratively approaching the optimal solution based on the gradient descent method.

[0050] Preferably, the process of adjusting the working condition parameters of the dewatering and drying component by using the guide parameter is:

[0051] S501, obtain the target bottom mud consolidation degree;

[0052] According to the pore water pressure, the pore water pressure dissipation value Δus i of the target bottom mud is obtained, and the target bottom mud consolidation degree U s is equal to the sample bottom mud consolidation degree U t ;

[0053]

[0054] In the formula: P is the dewatering and drying preloading; u s0 The excess pore water pressure of the target bottom mud before dewatering and drying;

[0055] S502, according to the target bottom mud consolidation degree U s , match the fitting data of the quartic polynomial fitting;

[0056] Determine the soil state of the target bottom mud, associate the target bottom mud consolidation degree at the current time node with the sample bottom mud consolidation degree, and obtain the optimal drainage temperature Tz and the corresponding optimal permeability coefficient k of the sample bottom mud with the consolidation degree in the test.max ;

[0057] S503, setting the optimum temperature interval;

[0058] The optimum permeability coefficient k max The corresponding optimum drainage temperature T z , set as the central value, the upward temperature float is 5, and the downward temperature float is 5, that is, the optimum temperature interval (T z min , T z max ) is (T z -5, T z +5);

[0059] S504, maintaining the temperature of the target sediment in the optimum temperature interval (T z min , T z max ) by controlling the heating device; specifically:

[0060] When the temperature of the target sediment is higher than the temperature control interval, turn off the heating element and stop heating;

[0061] When the temperature of the target sediment is lower than the temperature control interval, turn on the heating element and start heating.

[0062] Preferably, the data acquisition module comprises an air pressure sensor for acquiring the vacuum degree under the membrane, a temperature sensor for acquiring the soil temperature, a pressure sensor for acquiring the pore water pressure, and an Internet of Things electric meter for monitoring the electric energy consumption.

[0063] Preferably, a proximal temperature sensor is arranged around each heating element, and the proximal temperature sensor is located at the same depth as the heating element; a distal temperature sensor is arranged between two adjacent heating elements, and the distance between the two heating elements is equal.

[0064] Preferably, one proximal temperature sensor is arranged around each heating element, and L distal temperature sensors are arranged between two adjacent heating elements; when L is equal to 1, the distal temperature sensor is located at the same depth as the two heating elements; when L is greater than 1, the L distal temperature sensors are located at different depths.

[0065] Preferably, the arrangement method of the heating element is as follows:

[0066] The heating element is buried: the heating element is placed at the bottom or middle of the drainage plate in a form perpendicular to the construction operation surface;

[0067] The heating element comprises a hollow cylindrical heating body, a heater is arranged in the sandwich of the heating body, the heater is connected with an external power supply through a wire, so that the inner cavity of the heating body forms a heating cavity, the upper and lower ends of the heating body are respectively provided with water-permeable and air-permeable stone materials for connecting the heating cavity with the outside, the inner cavity of the heating body is provided with a support rod, the upper and lower ends of the support rod respectively extend into the water-permeable and air-permeable stone materials, and a pressing portion is arranged at the lower end of the support rod and penetrates through the water-permeable and air-permeable stone materials.

[0068] Releasing the heating body and connecting the circuit;

[0069] Reducing the water content of dredged sludge under the action of temperature and pressure coupling: when the conventional vacuum preloading drainage consolidation is carried out to the later stage, the heating body is powered on to heat the dredged sludge, and at the same time, the vacuum drainage is continued, by controlling the temperature of the heating body and the vacuum negative pressure of the dredged sludge, the water molecules in the dredged sludge are quickly converted from liquid to gas, and are discharged through the drainage plate, so that the water content of the dredged sludge is reduced;

[0070] S4, constant temperature control of the heating body.

[0071] Preferably, the drainage assembly comprises a drainage plate, and a vacuum negative pressure device connected with a drainage pipe.

[0072] Preferably, the drainage plate is provided with at least P levels of independent drainage systems, wherein P is a natural number greater than 1.

[0073] Preferably, each level of drainage system comprises a plurality of drainage plate monomers arranged in the transverse and longitudinal directions of the target sludge, and the depths of the drainage plate monomers of the same level are the same.

[0074] The drainage plate monomers of the lower level drainage system are arranged between the drainage plate monomers of the upper level drainage system, and the upper ends of the drainage plate monomers of the lower level drainage system overlap the lower ends of the drainage plate monomers of the upper level drainage system by a distance.

[0075] The first level drainage system is arranged in the shallow layer of the target sludge, and the upper end of each drainage plate monomer of the first level drainage system is connected with a first level water vapor separation bottle through a joint and a first level drainage branch pipe.

[0076] The air suction port of the first level water vapor separation bottle is connected with a first level vacuum negative pressure device through a first level air suction main pipe, and the drainage port of the first level water vapor separation bottle is connected with a drainage main pipe or a drainage ditch through a drainage pipe.

[0077] In addition to the upper end of the drainage plate monomer of the above-mentioned first-stage drainage system being connected to the first-stage water-vapor separation bottle through a joint and a first-stage drainage branch pipe, the lower end of the drainage monomer of the rest of the stage drainage system is connected to the corresponding stage water-vapor separation bottle through a joint and a corresponding stage drainage branch pipe which is independent of each other; the air suction port of each stage water-vapor separation bottle is connected to the corresponding stage vacuum negative pressure equipment which is independently controlled through a corresponding stage air suction main pipe; and the drainage port of each stage water-vapor separation bottle is connected to the drainage main pipe or the drainage ditch through a connecting drainage pipe.

[0078] The second object of the present application is to provide an ecological dredged sediment temperature-pressure coupling thermal phase change dehydration method, comprising:

[0079] S1, obtaining target sediment;

[0080] S2, obtaining the guiding parameters of the target sediment: first, extracting sample sediment from the target sediment, arranging data acquisition modules and dehydration drying components in the sample sediment, then performing a temperature-pressure coupling thermal phase change dehydration experiment on the sample sediment, collecting experimental data through the data acquisition modules during the experiment, the experimental data including the temperature, permeability coefficient, degree of consolidation, water discharge rate, sedimentation rate and pore water pressure change rate of the sample sediment, and finally selecting experimental data meeting the target requirements as guiding parameters through analysis of the experimental data; the dehydration drying components include heating elements, drainage assemblies and vacuum pumping equipment; wherein:

[0081] The analysis of the experimental data includes:

[0082] Analysis I: through analysis of the water discharge rate, sedimentation rate, pore water pressure change rate and temperature of the sample sediment, the phase change point temperature of water in the sample sediment under different vacuum degrees is obtained; the specific analysis process for each vacuum degree is as follows:

[0083] When the vacuum degree is determined, the sample sediment is gradually heated, and the temperature, water discharge rate, sedimentation rate and pore water pressure change rate during the heating process are obtained, and finally the temperature T w at the water discharge rate mutation point, the temperature T s at the sedimentation rate mutation point and the temperature T v at the pore water pressure change rate mutation point are extracted, and the maximum value among T v , T w and T s is selected as the phase change point temperature T;

[0084] Analysis II: the most suitable drainage temperature Tz of the sample sediment under different degrees of consolidation and the permeability coefficient k max under the most suitable drainage temperature Tz under different vacuum degrees are obtained.

[0085] S3, arranging data acquisition modules and dehydration drying components in the target sediment;

[0086] S4, performing temperature-pressure coupling thermal phase change dewatering and drying treatment on the target sediment by using the dewatering and drying component, and collecting state parameters of the target sediment in real time or at regular time intervals during the treatment;

[0087] S5, comparing the state parameters with the guidance parameters, selecting a guidance parameter with the smallest difference from the guidance parameters, and adjusting the working condition parameters of the dewatering and drying component by using the guidance parameter; the guidance parameters include a heating temperature and a vacuum degree of the target sediment; the heating temperature is not greater than T+5.

[0088] Preferably, S1 is specifically:

[0089] S101, determining a target area of the ecological dredged sediment;

[0090] S102, establishing an isolation zone around the target sediment in the target area, or transferring the target sediment in the target area to an isolation zone;

[0091] S103, setting a covering sealing film on the target area.

[0092] Preferably, S2 is specifically:

[0093] S201, extracting a single or M portions of sample sediment from the same position or different positions of the target sediment, M being a natural number greater than 1, and arranging a data collection module and a dewatering and drying component in each portion of sample sediment;

[0094] S202, performing temperature-pressure coupling thermal phase change dewatering and drying experiments on each portion of sample sediment, and collecting experimental data in real time or at regular time intervals during the experiments;

[0095] S203, analyzing each portion of experimental data, and selecting experimental data meeting target requirements as guidance parameters of the target sediment in the sampling point area corresponding to the experimental data.

[0096] Preferably, the method for obtaining the phase transition temperature T is:

[0097] Step one: placing the sample sediment into a sealed container and performing vacuum extraction;

[0098] Step two: when the average water discharge rate is less than 10 g / h within 4-6 consecutive hours, gradually increasing the temperature of the sample sediment by 5-10°C each time; during the temperature increasing process:

[0099] measuring the water discharge rate of the sample sediment, and when the water discharge rate of the sample sediment instantaneously increases by more than 10 times, recording the temperature at this time as T w ;

[0100] Measuring the sample bottom mud sedimentation rate, when the sample bottom mud sedimentation rate instantaneously increases by more than 10 times, record the temperature at this time as T s ;

[0101] Measuring the rate of change of pore water pressure, when the rate of change of pore water pressure instantaneously increases by more than 10 times, record the temperature at this time as T v ;

[0102] Step three: select the maximum value of T w , T s and T v as the phase transition point temperature T.

[0103] Preferably, under the condition of negative pressure of 80KPA, the consolidation degree experiment includes:

[0104] S2-1, test the permeability coefficient k i of the sample bottom mud under the condition of negative pressure in the temperature interval; the temperature interval is T i (20, 60); the negative pressure condition is 80KPA;

[0105] S2-2, the sample bottom mud temperature t i and the permeability coefficient k i are fitted by a fourth order polynomial;

[0106] The expression of the curve after the fourth order polynomial fitting is:

[0107] k i = a0+a1t i +a2t i 2 +a3t i 3 +a4t i m ;

[0108] In the formula: a0, a1, a2, a3, a4 are all fitting coefficients;

[0109] S2-3, through the curve, obtain the optimal drainage temperature T z and the optimal permeability coefficient k max under the optimal drainage temperature Tz;

[0110] The second order derivative function of the curve is:

[0111] k” = 2a2+6a3t i +12a4t i 2 ;

[0112] Where: t i is the temperature of the sample bottom mud;

[0113] Let k"=0; the optimum drainage temperature T z is:

[0114]

[0115] The optimum drainage temperature corresponds to the optimal permeability coefficient k max is:

[0116] k max =a0+a1T z +a2T z 2 +a3T z 3 +a3T z 4 ;

[0117] S2-4, under stable pressure conditions, the permeability coefficient of the sample bottom mud under different consolidation states is measured;

[0118] The degree of consolidation U t is established by using a nonlinear fitting method; max The optimum permeability coefficient k z The optimum drainage temperature T t changes characteristic curve;

[0119] Under different degrees of consolidation U max , repeat S2-1-S2-3, to obtain the optimum drainage temperature T z of the sample bottom mud under different consolidation states with the optimal permeability coefficient k t ;

[0120] S2-5, in the process of increasing the degree of consolidation U t , the relationship between the degree of consolidation U z and the optimum drainage temperature T i is established.

[0121] Preferably, the specific steps of the quartic polynomial fitting are: using the loss function Loss minimization to obtain the quartic polynomial optimal solution, or iterative approximation of the optimal solution based on gradient descent method.

[0122] Preferably, the process of adjusting the working condition parameters of the dewatering and drying component by using the guide parameter is:

[0123] S501, the target bottom mud consolidation degree is obtained;

[0124] According to the pore water pressure, the pore water pressure dissipation value Δus i of the target bottom mud is obtained, and the target bottom mud consolidation degree U s is equal to the sample bottom mud consolidation degree U t ;

[0125]

[0126]

[0127] In the formula, P is the preloading of dewatering and drying; u s0 is the target over-consolidation ratio of the target sediment before dewatering and drying;

[0128] S502, according to the target sediment consolidation degree U s , the fitting data of the quartic polynomial fitting is matched;

[0129] determining the soil state of the target sediment, associating the target sediment consolidation degree at the current time node with the consolidation degree of the sample sediment, and obtaining the optimal drainage temperature Tz and the corresponding optimal permeability coefficient k max of the sample sediment with the consolidation degree in the test;

[0130] S503, setting the optimal temperature interval;

[0131] the optimal permeability coefficient k max and the corresponding optimal drainage temperature T z are set as the center values, the upward temperature float is 5, and the downward temperature float is 5, i.e., the optimal temperature interval (T z min , T z max ) is (T z -5, T z +5);

[0132] S504, maintaining the temperature of the target sediment in the optimal temperature interval (T z min , T z max ) by controlling the heating device; specifically:

[0133] when the temperature of the target sediment is higher than the temperature control interval, the heating element is turned off and the heating is stopped;

[0134] when the temperature of the target sediment is lower than the temperature control interval, the heating element is turned on and the heating is started.

[0135] Preferably, the heating element is arranged as follows:

[0136] the heating element is buried: the heating element is placed at the bottom or middle of the drainage plate in a form perpendicular to the construction operation surface;

[0137] The heating element comprises a hollow cylindrical structure heating body, a heater is arranged in the sandwich of the heating body, the heater is connected with an external power supply through a wire, so that the inner cavity of the heating body forms a heating cavity, the upper and lower ends of the heating body are respectively provided with water-permeable and air-permeable stone materials for connecting the heating cavity with the outside, the inner cavity of the heating body is provided with a support rod, the upper and lower ends of the support rod respectively extend into the water-permeable and air-permeable stone materials, and a pressing portion is arranged at the lower end of the support rod and penetrates through the water-permeable and air-permeable stone materials.

[0138] Releasing the heating body and connecting the circuit;

[0139] Reducing the water content of dredged sludge under the action of temperature and pressure coupling: when the conventional vacuum preloading drainage consolidation is carried out to the later stage, the heating body is powered on to heat the dredged sludge, and at the same time, the vacuum drainage is continued, by controlling the temperature of the heating body and the vacuum negative pressure of the dredged sludge, the water molecules in the dredged sludge are quickly converted from liquid to gas, and are discharged through the drainage plate, so that the water content of the dredged sludge is reduced.

[0140] S4, constant temperature control of the heating body.

[0141] Preferably, the drainage assembly comprises a drainage plate, and a drainage pipe connected with a vacuum negative pressure device; the drainage plate is provided with at least P level independent drainage systems, wherein P is a natural number greater than 1.

[0142] Preferably, P is equal to 3, and the arrangement method of the three level independent drainage systems is as follows:

[0143] 1) The depth of each level drainage plate system and the length of each level drainage plate monomer are determined according to the depth of the target sludge;

[0144] 2) The drainage plate monomer of the third level drainage system with the deepest depth is first set, then the second level drainage system is set, and finally the first level drainage system is set;

[0145] When the third level drainage system is set, the lower end of the third level drainage monomer prepared in advance is sealed and connected with the third level drainage branch pipe through a sealing clamp, one end of the third level drainage branch pipe is downward, and the drainage plate monomers of the third level drainage system are set one by one according to the set spacing and the drainage plate monomer layout in the horizontal and vertical directions;

[0146] When the second level drainage system is set, the lower end of the second level drainage monomer prepared in advance is sealed and connected with the second level drainage branch pipe through a sealing clamp, one end of the second level drainage branch pipe is downward, the drainage plate monomers of the second level drainage system are located between the drainage plate monomers of the P level drainage system, and the drainage plate monomers of the second level drainage system are set one by one according to the set spacing and the drainage plate monomer layout in the horizontal and vertical directions when setting; the setting depth of the drainage plate monomers of the second level drainage system overlaps with the upper end of the drainage plate monomers of the third level drainage system by a distance.

[0147] In the process of setting up the first-stage drainage system, the upper end of the prepared first-stage drainage system drainage monomer is sealed and connected with the first-stage drainage branch pipe, one end of the first-stage drainage branch pipe is upward, and the first-stage drainage system drainage monomer is located between the second-stage drainage system drainage monomers; in the process of setting up, the first-stage drainage system drainage monomers are set up one by one according to the set spacing and drainage monomer layout in the horizontal and vertical directions; the setting-up depth of the first-stage drainage system drainage monomer overlaps the upper end of the second-stage drainage system drainage monomer by a distance;

[0148] 3) Connect the drainage branch pipe of each stage of drainage system with the corresponding water vapor separation bottle, and connect the water vapor separation bottle of each stage with the corresponding vacuum negative pressure equipment or vacuum negative pressure station through the drainage main pipe, and connect the drainage port of the water vapor separation bottle of each stage with the drainage main pipe or drainage ditch through the drainage pipe;

[0149] 4) Arrange a data acquisition system, which comprises a pressure acquisition device for acquiring vacuum pressure, a water level acquisition device for acquiring water level, a surface settlement acquisition device for acquiring surface settlement, and a target bottom sediment pore water pressure acquisition device;

[0150] 5) Lay woven cloth, geotextile and sealing membrane on the working cushion in sequence, the sealing membrane extends to the sealing ditch at the periphery, and the sealing ditch is backfilled with sealing soil;

[0151] 6) Connect the drainage main pipe of each stage of drainage system with the corresponding vacuum negative pressure equipment or vacuum negative pressure station respectively, open the vacuum negative pressure equipment, debug the vacuum negative pressure equipment, and detect whether there is air leakage, and if there is air leakage, carry out sealing repair treatment.

[0152] The application has the advantages and positive effects that:

[0153] The application firstly samples the target bottom sediment to obtain sample bottom sediment, because the properties of the sample bottom sediment are basically consistent with those of the target bottom sediment, therefore, the optimal temperature-pressure coupling thermal phase change type dehydration and drying related data (such as phase change point temperature, pore water pressure data, drainage efficiency under different temperatures and pressures, power consumption, etc.) can be obtained through the temperature-pressure coupling thermal phase change type dehydration and drying experimental analysis of the sample bottom sediment, then the optimal temperature-pressure coupling thermal phase change type dehydration and drying related data are used as guiding parameters, and finally the guiding parameters are used to realize the temperature-pressure coupling thermal phase change type dehydration and drying process of the target bottom sediment efficiently. BRIEF DESCRIPTION OF DRAWINGS

[0154] Figure 1 The flowchart of the preferred embodiment of the application;

[0155] Figure 2 The flowchart of obtaining the target bottom sediment in the preferred embodiment of the application;

[0156] Figure 3 Flow chart for guiding parameter acquisition in preferred embodiments of the present application;

[0157] Figure 4 Flow chart for consolidation experiment in preferred embodiments of the present application;

[0158] Figure 5 Flow chart for adjusting working condition parameters of dewatering and drying components using the guiding parameters in preferred embodiments of the present application. DETAILED DESCRIPTION

[0159] In order to make the above-mentioned objectives, design, control system and advantages of the present application more clear and understandable, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0160] As shown in Figures 1 to 5 the technical scheme of the present application is:

[0161] An ecological dredged sediment temperature-pressure coupling heat phase change type dewatering and drying system, comprising:

[0162] The first acquisition part: acquires target sediment; in the present application, the target sediment is taken as an example of river, lake and reservoir dredged sediment, which needs to be separated from the surrounding environment before dewatering and drying, otherwise the water in the surrounding environment will continuously infiltrate into the dewatering and drying area during the dewatering and drying process; the acquisition process of the first acquisition part is: S101, determining the target area of the ecological dredged sediment; mainly including the geographical position coordinate area of the dewatering and drying area; S102, separating the target sediment from the surrounding environment: that is, establishing an isolation belt around the target sediment in the target area, thereby obtaining the in-situ target sediment, or transferring the target sediment in the target area to an isolation area; for example, transferring the target sediment in the target area to a dredged channel, and then setting two diaphragm dams in the dredged channel; S103, pretreating the target sediment, which includes: removing sundries, and setting a covering sealing film on the target area; for example, to achieve better negative pressure effect, a working cushion layer can be set on the target area, and then woven cloth, geotextile and sealing film are sequentially laid on the working cushion layer;

[0163] The second acquisition unit acquires the guiding parameters of the target sediment. First, a sample sediment is extracted from the target sediment, and the sample sediment has substantially the same properties as the target sediment, such as the same optimal parameters of temperature-pressure coupling thermal phase change type dewatering and drying. Then, a data acquisition module and a dewatering and drying component are arranged in the sample sediment. Then, a temperature-pressure coupling thermal phase change type dewatering and drying experiment is performed on the sample sediment. During the experiment, the data acquisition module acquires experimental data, including the temperature, vacuum degree, permeability coefficient, consolidation degree, water discharge rate, sedimentation rate, and pore water pressure change rate of the sample sediment. Finally, the experimental data that meets the target requirements is selected as the guiding parameters through analysis of the experimental data.

[0164] The analysis of the experimental data includes:

[0165] Analysis I: Through analysis of the water discharge rate, sedimentation rate, pore water pressure change rate, and temperature of the sample sediment, the phase change point temperature of water in the sample sediment under different vacuum degrees is obtained. The specific analysis process for each vacuum degree is as follows:

[0166] When the vacuum degree is determined, the sample sediment is gradually heated, and the temperature, water discharge rate, sedimentation rate, and pore water pressure change rate during the heating process are obtained. Finally, the temperature T w at the water discharge rate mutation point, the temperature T s at the sedimentation rate mutation point, and the temperature T v at the pore water pressure change rate mutation point are extracted, and the maximum value among T v , T w , and T s is selected as the phase change point temperature T. For example, the method for obtaining the phase change point temperature T is as follows:

[0167] Step 1: Place the sample sediment in a sealed container and perform vacuum pumping.

[0168] Step 2: When the average water discharge rate is less than 10 g / h for 4-6 consecutive hours, gradually increase the temperature of the sample sediment by 5-10°C each time. During the temperature increasing process:

[0169] Measure the water discharge rate of the sample sediment. When the water discharge rate of the sample sediment instantaneously increases by more than 10 times, record the temperature at this time as T w .

[0170] Measure the sedimentation rate of the sample sediment. When the sedimentation rate of the sample sediment instantaneously increases by more than 10 times, record the temperature at this time as T s .

[0171] Measuring the rate of change of pore water pressure, when the rate of change of pore water pressure instantaneously increases by more than 10 times, recording the temperature at this time as T v ;

[0172] Step three: selecting the maximum value of T w , T s and T v as the phase transition point temperature T.

[0173] Through the above analysis one, the phase transition point temperature of water in the sample bottom mud under different vacuum negative pressures can be determined. In the construction process, the heating temperature can be set according to the size of the vacuum degree on site. The heating temperature is set in the range of the phase transition point temperature T to T+5℃. According to the model test, the limit of 5℃ is taken to ensure that the water in the soil is fully phase transition, and the influence on the properties of the bottom mud is minimal, so as to avoid the hardening of the soil structure and the formation of a "heat and water insulation barrier". Generally, the surface in the conventional vacuum preloading construction is between 80 to 85kpa. However, the vacuum degree is different at different depths, and the vacuum degree decreases with the depth. The gasification point is different under different vacuum pressures, and the phase transition point temperature is also different for different depths.

[0174] The guidance parameters include the heating temperature of the target bottom mud; the heating temperature is not greater than T+△T, and the range of△T is 0~5; when the heating temperature is too high, the bottom mud will be quickly dehydrated and hardened, and then a layer of clay heat and water insulation layer will be formed, which will block the conduction of temperature and reduce the seepage path of water, resulting in poor dehydration and drying effect in a large range. At the same time, the high temperature will result in high energy consumption, high cost, poor stability and safety. Therefore, the selection of the heating temperature not only affects the dehydration and drying efficiency, but also affects the utilization rate of energy consumption;

[0175] Analysis two: obtaining the most suitable drainage temperature Tz of the sample bottom mud at different degrees of consolidation under different vacuum conditions and the permeability coefficient k under the most suitable drainage temperature Tz max ;

[0176] The degree of consolidation is also an important factor affecting the dehydration and drying efficiency. Therefore, in the preferred embodiment, the obtaining process of the second obtaining part further includes obtaining guidance parameters through a consolidation degree experiment, the guidance parameters including the most suitable drainage temperature Tz of the sample bottom mud having optimal drainage characteristics under different states of the degree of consolidation Ut and the permeability coefficient k under the most suitable drainage temperature Tz max ; the consolidation degree experiment includes:

[0177] S2-1, testing the permeability coefficient k of the sample bottom mud in the temperature interval under negative pressure conditions i ; the temperature interval is T i (20, 60); it is assumed that the negative pressure condition is 80KPA;

[0178] S2-2, the temperature t of the sample bottom mud i and the permeability coefficient k i Perform a four-order polynomial fitting;

[0179] The expression of the curve after four-order polynomial fitting is:

[0180] k i = a0 + a1t i + a2t i 2 + a3t i 3 + a4t i 4 ;

[0181] In the formula, a0, a1, a2, a3, and a4 are fitting coefficients;

[0182] In this step, curve fitting can be performed by two algorithms, which are:

[0183] (1) Based on the minimization of the loss function Loss, that is, the optimal solution of the polynomial is obtained;

[0184]

[0185]

[0186] Let: 5 equations of simplified partial derivative = 0:

[0187]

[0188] Convert to matrix multiplication form:

[0189]

[0190] Two matrix multiplications:

[0191] XA = Y;

[0192] Wherein: A is the coefficient matrix of the polynomial;

[0193] Use Gaussian elimination method to perform elementary row transformation on the augmented matrix of the linear equation set, solve the coefficients, and obtain the fitting curve, wherein k i is the permeability coefficient corresponding to the t i moment:

[0194] k i = a0 + a1t i + a2t i 2 + a3t i 3 + a3t i 4

[0195] (2) Based on gradient descent method to approach the optimal solution iteratively;

[0196] Calculate the gradient value Gradient_a corresponding to each coefficient k :

[0197]

[0198] Update the corresponding coefficient a k :

[0199] a k = a k + learn rate × gradient_a k ;

[0200] Get the fitting curve:

[0201] k = a0 + a1t0 + a2t0 2 + a3t0 3 + a3t0 4 ;

[0202] S2-3, through the curve, get the optimal drainage temperature T z and the optimal permeability coefficient k under the optimal drainage temperature Tz max ;

[0203] Second-order derivative function of the curve:

[0204] k” = 2a2 + 6a3t i + 12a4t i 2 ;

[0205] Where: t i is the temperature of the soil sample;

[0206] Let k” = 0; as Figure 3 shown: the overall shape of the curve is open downward, so a4 < 0, so its second-order derivative function k” is an open downward parabola, there are two zeros, given the condition 20-60℃ interval k increases with t monotonically, therefore, the left zero point is the minimum point of the derivative function k', and the minimum value is zero, the right zero point is a maximum point of its derivative function k', this point is the point to be solved.

[0207] Then the optimal drainage temperature T z is:

[0208]

[0209] The optimal permeability coefficient k max corresponding to the optimal drainage temperature is:

[0210] k max = a0 + a1T z + a2T z 2 + a3T z 3 + a3T z 4 ;

[0211] S2-4, under stable pressure conditions, the permeability coefficient of the sample bottom mud under different consolidation states is determined;

[0212] The degree of consolidation U t is established by using a nonlinear fitting method. max The optimal permeability coefficient k z of the sample bottom mud under different consolidation states is determined.

[0213] Under different degrees of consolidation U t , steps S2-1 to S2-3 are repeated to determine the optimal drainage temperature T max of the sample bottom mud under different consolidation states. z ;

[0214] S2-5, during the increase of the degree of consolidation U t , the relationship between the degree of consolidation U t and the optimal drainage temperature T z is established.

[0215] The specific steps of the quartic polynomial fitting are: obtaining the optimal solution of the quartic polynomial by using the loss function Loss minimization, or iteratively approximating the optimal solution based on the gradient descent method.

[0216] The process of adjusting the working condition parameters of the dewatering and drying component by using the guidance parameter is:

[0217] S501, the target bottom mud consolidation degree is determined.

[0218] According to the pore water pressure, the pore water pressure dissipation value Δus i of the target bottom mud is determined, and the target bottom mud consolidation degree U s is equal to the sample bottom mud consolidation degree U t ;

[0219]

[0220] In the formula: P is the dewatering and drying preloading; u s0 is the excess pore water pressure of the target bottom mud before dewatering and drying;

[0221] S502, according to the target bottom mud consolidation degree U s, matching a fourth polynomial fitting to the fitted data;

[0222] determining the soil state of the target bottom mud, associating the consolidation degree of the target bottom mud at the current time node with the consolidation degree of the sample bottom mud, obtaining the optimal drainage temperature Tz and the corresponding optimal permeability coefficient k of the sample bottom mud with the consolidation degree in the test max ;

[0223] S503, setting the optimal temperature interval;

[0224] The optimal permeability coefficient k max corresponding to the optimal drainage temperature T z , set as the center value, the upward temperature float is △T1, and the downward temperature float is △T2, that is, the optimal temperature interval (T z min , T z max ) is (T z -△T2, T z +△T1); in the preferred embodiment, △T1=△T2=5;

[0225] S504, by controlling the heating device, the temperature of the target bottom mud is maintained in the optimal temperature interval (T z min , T z max ); Specifically:

[0226] When the temperature of the target bottom mud is higher than the temperature control interval, the heating element is turned off and the heating is stopped;

[0227] When the temperature of the target bottom mud is lower than the temperature control interval, the heating element is turned on and the heating is started.

[0228] Laying part: laying data acquisition module and dewatering and drying components in the target bottom mud; the dewatering and drying components include heating elements, drainage components and vacuum pumping equipment;

[0229] Information acquisition part: using the dewatering and drying components to carry out temperature-pressure coupling thermal phase change type dewatering and drying treatment on the target bottom mud, and collecting the state parameters of the target bottom mud in real time or at regular intervals during the treatment; The main purpose of the information acquisition part is to detect the vacuum pressure, pore water pressure, heating energy consumption, temperature of the bottom mud and change of groundwater level in the treatment area at different positions of the treated bottom mud; wherein: the temperature of the bottom mud is realized by temperature sensors, which are arranged around the heating elements; The pore water pressure and water level monitoring equipment 5 (water level sensor) is arranged around the drainage plate and is arranged at the middle position of adjacent drainage plates; In the preferred embodiment, the water level monitoring equipment selects JM-90 type steel ruler water level gauge.

[0230] Monitoring method: temperature and pore water pressure are monitored at regular intervals, automatic reading and recording every hour, real-time monitoring of vacuum pressure, heating energy consumption, and groundwater level.

[0231] Temperature and pressure anomaly warning and disposal: the boiling point of water changes under different pressures, and the boiling point of water under different pore water pressures is different. Through the monitoring of temperature, pressure, groundwater level and pore water pressure, and through the changes in the power-on time and power-on interval, it is ensured that the temperature near the heating element does not exceed the boiling point of water, and the temperature at the distal end of the heating element is appropriately increased. Engineers adjust the working parameters of the heating element based on the monitoring results.

[0232] Control unit: compare state parameters with guidance parameters, select the guidance parameter with the smallest difference from the guidance parameters, and adjust the working condition parameters of the dewatering and drying component using the guidance parameter; the guidance parameters include the heating temperature and vacuum degree of the target sediment; the heating temperature is not greater than T+△T, and △T is in the range of 0-5.

[0233] In the above preferred embodiment, when the range of the target sediment is relatively large, the properties of the sediment at different positions may differ significantly, so multiple sampling points are needed, and the acquisition process of the second acquisition unit is:

[0234] S201, extracting a single or M samples of the target sediment from the same or different positions of the target sediment, M being a natural number greater than 1, and arranging a data acquisition module and a dewatering and drying component in each sample of the sediment;

[0235] S202, performing a temperature-pressure coupled thermal phase change dewatering and drying experiment on each sample of the sediment, and collecting experimental data in real time or at regular intervals during the experiment;

[0236] S203, analyzing each experimental data and selecting experimental data meeting the target requirements as the guidance parameters of the target sediment in the sampling point area corresponding to the experimental data.

[0237] A proximal temperature sensor is arranged around each heating element, and the proximal temperature sensor is located at the same depth as the heating element. A distal temperature sensor is arranged between two adjacent heating elements, and the distance between the distal temperature sensor and the two heating elements is equal, and multiple distal temperature sensors are located on the central axis of the two heating elements.

[0238] A proximal temperature sensor is arranged around each heating element. L distal temperature sensors are arranged between two adjacent heating elements. When L is equal to 1, the distal temperature sensor is located at the same depth as the two heating elements. When L is greater than 1, the L distal temperature sensors are located at different depths.

[0239] In the embodiment, the proximal temperature sensor is arranged at a position 0.5 m away from the heating element, the distal temperature sensor is arranged at a position between the two heating elements, the distance between the two heating elements is greater than 1 m, the proximal temperature sensor is arranged with only one temperature sensor at the same depth as the heating element, the distal temperature sensor is distributed in layers in the vertical direction, and the distribution mode is different according to the processing depth and the horizontal distance between the heating elements. When the processing depth is less than the distance between the heating elements, one temperature sensor is arranged, and when the processing depth is greater than the distance between the heating elements, two temperature sensors are arranged at the distal end.

[0240] The dewatering and drying component comprises a heating element and a drainage assembly.

[0241] The arrangement method of the heating element is as follows:

[0242] The heating element is buried: the heating element is placed at the bottom or middle of the drainage board in a form perpendicular to the construction operation surface;

[0243] The heating element comprises a hollow columnar structure heating body, a heater is arranged in the interlayer of the heating body, the heater is connected with an external power supply through a wire, so that the inner cavity of the heating body forms a heating cavity, water-permeable and air-permeable stone materials for connecting the heating cavity with the outside are arranged at the upper and lower ends of the heating body, a support rod is arranged in the inner cavity of the heating body, the upper and lower ends of the support rod extend into the water-permeable and air-permeable stone materials, respectively, and a pressing portion is arranged at the lower end of the support rod and penetrates through the water-permeable and air-permeable stone materials;

[0244] The heating body is released and the circuit is connected;

[0245] Under the action of temperature and pressure coupling, the water content of the dredged sludge is reduced: when the conventional vacuum preloading drainage consolidation is carried out to the later stage, the heating body is powered on to heat the dredged sludge, and at the same time, the vacuum drainage is continued. By controlling the temperature of the heating body and the vacuum negative pressure of the dredged sludge, the water molecules in the dredged sludge are quickly converted from liquid to gas, and are discharged through the drainage board, thereby reducing the water content of the dredged sludge;

[0246] The heating body is controlled at a constant temperature.

[0247] The drainage assembly mainly comprises a drainage board and a drainage pipe connected with a vacuum negative pressure equipment.

[0248] The drainage board is provided with at least P independent drainage systems, wherein P is a natural number greater than 1. In the embodiment, P is 3;

[0249] Each drainage system comprises a plurality of drainage board monomers arranged in the lateral and longitudinal directions of the target sludge, and the depths of the drainage board monomers in the same level are the same;

[0250] The lower level drainage system is laid between the drainage plate units of the upper level drainage system, and the upper end of the drainage plate unit of the lower level drainage system overlaps the lower end of the drainage plate unit of the upper level drainage system by a distance;

[0251] The upper end of each drainage plate unit of the first level drainage system is connected to a first water-vapor separation bottle through a joint and a first level drainage branch pipe;

[0252] The air outlet of the first water-vapor separation bottle is connected to a first vacuum negative pressure device through a first air suction main pipe, and the water outlet of the first water-vapor separation bottle is connected to a drainage main pipe or a drainage ditch through a drainage pipe;

[0253] In addition to the upper end of the drainage plate unit of the first level drainage system being connected to the first water-vapor separation bottle through the joint and the first level drainage branch pipe, the lower end of the drainage plate unit of the remaining levels of drainage systems is connected to the water-vapor separation bottle of the corresponding level through a joint and a corresponding level drainage branch pipe that is independent of each other; the air outlet of the water-vapor separation bottle of each level is connected to a corresponding level vacuum negative pressure device that is independently controlled through a corresponding level air suction main pipe, and the water outlet of the water-vapor separation bottle of each level is connected to the drainage main pipe or the drainage ditch through a drainage pipe.

[0254] An ecological dredged sediment temperature-pressure coupling heat phase change dehydration method, comprising:

[0255] S1, obtaining target sediment; In this application, the target sediment is taken as the dredged sediment of rivers, lakes and reservoirs. Before dehydration and drying, the target sediment needs to be separated from the surrounding environment, otherwise the water in the surrounding environment will continuously seep into the dehydration and drying area during the dehydration and drying process. The first obtaining part obtains the target sediment as follows: S101, determining the target area of the ecological dredged sediment; mainly including the geographical position coordinate area of the dehydration and drying area; S102, separating the target sediment from the surrounding environment: that is, establishing an isolation belt around the target sediment in the target area, thereby obtaining the in-situ target sediment, or transferring the target sediment in the target area to an isolation area; for example, transferring the target sediment in the target area to a dredged channel, and then setting two diaphragm dams in the dredged channel; S103, pretreating the target sediment, which includes: removing sundries and setting a covering sealing film on the target area. In order to achieve better negative pressure effect, a working cushion layer can be set on the target area, and then a woven cloth, a geotextile and a sealing film are sequentially laid on the working cushion layer;

[0256] S2, obtaining the guiding parameters of the target sediment: first, extracting a sample sediment from the target sediment, the sample sediment and the target sediment are basically consistent in nature, such as the best parameters of the temperature-pressure coupling thermal phase change type dewatering and drying of the two are consistent, arranging the data acquisition module and the dewatering and drying component in the sample sediment, then performing a temperature-pressure coupling thermal phase change type dewatering and drying experiment on the sample sediment, in the process of the experiment, collecting experimental data through the data acquisition module, the experimental data includes the temperature, vacuum degree, permeability coefficient, consolidation degree, water discharge rate, sedimentation rate and pore water pressure change rate of the sample sediment, and finally selecting experimental data meeting the target requirements as the guiding parameters through analysis of the experimental data; in this embodiment: the data acquisition module includes an air pressure sensor for collecting the vacuum degree under the film, a temperature sensor for collecting the soil temperature, a pressure sensor for collecting the pore water pressure, and an Internet of Things electric meter for monitoring the electric power consumption; wherein:

[0257] The analysis of the experimental data includes:

[0258] Analysis I: through analysis of the water discharge rate, sedimentation rate, pore water pressure change rate and temperature of the sample sediment, the phase change point temperature of water in the sample sediment under different vacuum degrees is obtained; the specific analysis process under each vacuum degree is as follows:

[0259] When the vacuum degree is determined, the sample sediment is gradually heated, and the temperature, water discharge rate, sedimentation rate and pore water pressure change rate in the heating process are obtained, and finally the temperature T w at the water discharge rate mutation point, the temperature T s at the sedimentation rate mutation point and the temperature T v at the pore water pressure change rate mutation point are extracted, and the maximum value of T v , T w and T s is selected as the phase change point temperature T; for example, the method for obtaining the phase change point temperature T is as follows:

[0260] Step 1: place the sample sediment in a sealed container and perform vacuum pumping;

[0261] Step 2: when the average water discharge rate is less than 10 g / h for 4-6 h, gradually heat the sample sediment by 5-10 DEG C each time; during the heating process:

[0262] measure the water discharge rate of the sample sediment, when the water discharge rate of the sample sediment instantaneously increases by more than 10 times, record the temperature at this time as T w ;

[0263] measure the sedimentation rate of the sample sediment, when the sedimentation rate of the sample sediment instantaneously increases by more than 10 times, record the temperature at this time as T s ;

[0264] The rate of change of the pore water pressure is measured, and when the rate of change of the pore water pressure instantaneously increases by more than 10 times, the temperature at this time is recorded as T v ;

[0265] Step three: selecting the maximum value of T w , T s and T v as the phase transition point temperature T.

[0266] Through the above analysis one, the phase transition point temperature of water in the sample bottom mud under different vacuum negative pressures can be determined. In the construction process, the heating temperature can be set according to the size of the vacuum degree on site. The heating temperature is set in the range of the phase transition point temperature T to T+5℃. According to the model test, the limit of 5℃ is taken to ensure that the water in the soil is fully phase transition, and the influence on the properties of the bottom mud is minimal, so as not to cause the hardening of the soil structure, form a "heat and water insulation barrier", and the surface in the general conventional vacuum preloading construction is between 80 to 85kpa. However, the vacuum degree is different at different depths, and the vacuum degree decreases with the depth. The gasification point is different under different vacuum pressures, and the phase transition point temperature required is also different at different depths.

[0267] The guidance parameters include the heating temperature of the target bottom mud; the heating temperature is not greater than T+△T, and the range of△T is 0~5; when the heating temperature is too high, the bottom mud will be quickly dehydrated and hardened, and then a layer of clay heat and water insulation layer is formed, which blocks the conduction of temperature and reduces the seepage path of water, resulting in poor dehydration and drying effect in a large range. At the same time, the high temperature has high energy consumption, high cost, poor stability and safety; therefore, the selection of the heating temperature not only affects the dehydration and drying efficiency, but also affects the utilization rate of energy consumption;

[0268] Analysis two: obtaining the most suitable drainage temperature Tz of the sample bottom mud at different consolidation degrees under different vacuum conditions and the permeability coefficient k under the most suitable drainage temperature Tz max ;

[0269] The consolidation degree is also an important factor affecting the dehydration and drying efficiency, so in the preferred embodiment, the obtaining process of the second obtaining part further includes obtaining guidance parameters through a consolidation degree experiment, the guidance parameters including the most suitable drainage temperature Tz of the sample bottom mud having optimal drainage characteristics under different states of consolidation degree Ut and the permeability coefficient k under the most suitable drainage temperature Tz max ; the consolidation degree experiment includes:

[0270] S2-1, testing the permeability coefficient k of the sample bottom mud in the temperature interval under the negative pressure condition i ; the temperature interval is T i (20, 60); the negative pressure condition is generally set to 80KPA;

[0271] S2-2, the temperature t of the sample bottom mud i and the permeability coefficient k i Perform a four-order polynomial fitting; in this step, curve fitting can be performed by two algorithms, which are: (3) based on loss function Loss minimization, that is, to obtain the optimal solution of the polynomial;

[0272]

[0273] Let: 5 equations of simplified partial derivatives = 0:

[0274]

[0275] Convert to matrix multiplication form:

[0276]

[0277] Two matrix multiplications:

[0278] XA=Y;

[0279] Where: A is the coefficient matrix of the polynomial;

[0280] Use Gaussian elimination method to perform elementary row transformation on the augmented matrix of the linear equation set to solve each coefficient and obtain the fitting curve, where k i is the permeability coefficient corresponding to the time t i :

[0281] k i =a0+a1t i +a2t i 2 +a3t i 3 +a3t i 4

[0282] (4) Based on the gradient descent method to iteratively approach the optimal solution;

[0283] Calculate the gradient value Gradient_a k corresponding to each coefficient:

[0284]

[0285] Update the corresponding coefficient a k :

[0286] a k =a k +learn rate ×gradient_a k ;

[0287] Obtain the fitting curve:

[0288] k = a0 + a1t0 + a2t0 2 +a3t0 3 +a3t0 4 ;

[0289] S2-3, through the curve, obtain the optimal drainage temperature Tz z and the optimal permeability coefficient k under the optimal drainage temperature Tz max ;

[0290] The second derivative of the curve is obtained:

[0291] k” = 2a2 + 6a3t i + 12a4t i 2 ;

[0292] Where: t i is the temperature of the soil sample;

[0293] Let k” = 0; as Figure 3 shown: the overall shape of the curve is open downward, so a4 < 0, so its second derivative k” is an open downward parabola, there are two zeros, known conditions 20-60 ℃ interval, k increases with t monotonically, therefore, the left zero point is the minimum point of the derivative function k', and the minimum value is zero, the right zero point is a maximum point of its derivative function k', this point is the point to be solved.

[0294] Then the optimal drainage temperature T z is:

[0295]

[0296] The optimal permeability coefficient k max corresponding to the optimal drainage temperature is:

[0297] k max = a0 + a1T z +a2T z 2 +a3T z 3 +a3T z 4 ;

[0298] S2-4, under the condition of stable pressure, determine the permeability coefficient of the sample bottom mud under different consolidation states;

[0299] Use nonlinear fitting to establish the consolidation degree U t in the lifting process, the optimal drainage temperature T max of the optimal permeability coefficient k z changes characteristic curve;

[0300] Under different consolidation degrees U t , repeat S2-1-S2-3 to obtain the optimal drainage temperature T max of the sample bottom mud under different consolidation states with the optimal permeability coefficient k z ;

[0301] S2-5, during the increase of the consolidation degree U t , establish the correspondence between the consolidation degree U t and the optimal drainage temperature T z .

[0302] The specific steps of the quartic polynomial fitting are: obtaining the optimal solution of the quartic polynomial by using the loss function Loss minimization, or iteratively approximating the optimal solution based on the gradient descent method.

[0303] The process of adjusting the working condition parameters of the dewatering and drying component by using the guidance parameter is:

[0304] S501, obtain the target bottom mud consolidation degree;

[0305] According to the pore water pressure, obtain the pore water pressure dissipation value Δus i of the target bottom mud, and let the target bottom mud consolidation degree U s equal to the sample bottom mud consolidation degree U t ;

[0306]

[0307] In the formula: P is the dewatering and drying preloading; u s0 is the excess pore water pressure of the target bottom mud before dewatering and drying;

[0308] S502, according to the target bottom mud consolidation degree U s , match the fitting data of the quartic polynomial fitting;

[0309] Determine the soil state of the target bottom mud, associate the target bottom mud consolidation degree at the current time node with the sample bottom mud consolidation degree, and obtain the optimal drainage temperature Tz of the sample bottom mud with the consolidation degree in the test and the corresponding optimal permeability coefficient k max ;

[0310] S503, set the optimal temperature interval;

[0311] Set the optimal permeability coefficient k max corresponding to the optimal drainage temperature T z as the center value, the upward temperature float as ΔT1, and the downward temperature float as ΔT2, that is, the optimal temperature interval (T z min , T z max ) is (Tz -△T2, T z +△T1); in the preferred embodiment, △T1=△T2=5;

[0312] S504, maintaining the temperature of the target sediment in the optimum temperature range (T z min , T z max ) by controlling the temperature increasing device; specifically:

[0313] When the temperature of the target sediment is higher than the temperature control range, turn off the heating element and stop heating;

[0314] When the temperature of the target sediment is lower than the temperature control range, turn on the heating element and start heating.

[0315] S3, arranging data acquisition modules and dewatering and drying components in the target sediment;

[0316] S4, using the dewatering and drying components to perform temperature-pressure coupling thermal phase change dewatering and drying treatment on the target sediment, and collecting state parameters of the target sediment in real time or at regular intervals during the treatment;

[0317] S5, comparing the state parameters with the guidance parameters, selecting the guidance parameter with the smallest difference from the guidance parameters, and adjusting the working condition parameters of the dewatering and drying components using the guidance parameter; the guidance parameters include the heating temperature and the vacuum degree of the target sediment; the heating temperature is not greater than T+△T, and △T is in the range of 0-5.

[0318] S2 specifically includes:

[0319] S201, extracting single or M portions of sample sediment from the same position or different positions of the target sediment, M being a natural number greater than 1, and arranging data acquisition modules and dewatering and drying components in each portion of sample sediment;

[0320] S202, performing temperature-pressure coupling thermal phase change dewatering and drying experiments on each portion of sample sediment, and collecting experimental data in real time or at regular intervals during the experiments;

[0321] S203, analyzing each portion of experimental data, and selecting experimental data meeting the target requirements as the guidance parameters of the target sediment in the sampling point area corresponding to the experimental data.

[0322] The guide parameters include a heating temperature of the target bottom mud; the heating temperature is not greater than T+△T, and △T is in a range of 0-5; when the heating temperature is too high, the bottom mud is quickly dehydrated, hardened and solidified, and then a clay heat and water insulation layer is formed, the conduction of temperature is blocked, the seepage path of water is reduced, and a large range of dehydration and drying effect is poor; meanwhile, the high temperature has high energy consumption, high cost, poor stability and safety; in sequence, the selection of the heating temperature not only affects the dehydration and drying efficiency, but also affects the utilization rate of energy consumption;

[0323] The dehydration and drying component includes a heating element and a drainage assembly.

[0324] The heating element is arranged in the following manner:

[0325] The heating element is buried in the following manner: the heating element is placed at the bottom or middle of the drainage board in a form perpendicular to the construction operation surface;

[0326] The heating element includes a hollow columnar structure heating body, a heater is arranged in the interlayer of the heating body, the heater is connected with an external power supply through a wire, so that the inner cavity of the heating body forms a heating cavity, the upper and lower ends of the heating body are respectively provided with water-permeable and air-permeable stone materials for connecting the heating cavity with the outside, the inner cavity of the heating body is provided with a support rod, the upper and lower ends of the support rod extend into the water-permeable and air-permeable stone materials, respectively, and a pressing portion is arranged at the lower end of the support rod and penetrates through the water-permeable and air-permeable stone materials.

[0327] The heating body is released and the circuit is connected;

[0328] The water content of the dredged bottom mud is reduced under the temperature and pressure coupling effect: when the conventional vacuum preloading drainage consolidation is carried out to the later stage, the heating body is powered on to heat the dredged bottom mud, and vacuum drainage is continued, the temperature of the heating body and the vacuum negative pressure of the dredged bottom mud are controlled, so that the water molecules in the dredged bottom mud are quickly converted from liquid to gas, and are discharged through the drainage board, thereby reducing the water content of the dredged bottom mud.

[0329] The heating body is controlled at a constant temperature.

[0330] The drainage assembly includes drainage boards, and a drainage pipe connected with a vacuum negative pressure device; the drainage boards are provided with at least P-level independent drainage systems, wherein P is a natural number greater than 1.

[0331] When P is equal to 3, the arrangement method of the three-level independent drainage systems is as follows:

[0332] 1) The depth of each level of drainage board system and the length of each drainage board in each level of drainage system are determined according to the depth of the target bottom mud.

[0333] 2) Firstly, the drainage plate monomer of the third-level drainage system with the deepest depth is punched, and then the second-level drainage system is punched, and finally the first-level drainage system is punched;

[0334] In the process of punching the third-level drainage system, the lower end of the prepared drainage monomer of the third-level drainage system is sealed and connected with the third-level drainage branch pipe with one end of the third-level drainage branch pipe facing downward; the third-level drainage plate monomers are punched one by one according to the set spacing and the drainage plate monomer layout in the horizontal and vertical directions;

[0335] In the process of punching the second-level drainage system, the lower end of the prepared drainage monomer of the second-level drainage system is sealed and connected with the second-level drainage branch pipe with one end of the second-level drainage branch pipe facing downward, and the drainage plate monomers of the second-level drainage system are located between the drainage plate monomers of the P-level drainage system; when punching, the drainage plate monomers of the second-level drainage system are punched one by one according to the set spacing and the drainage plate monomer layout in the horizontal and vertical directions; the punching depth of the drainage plate monomers of the second-level drainage system overlaps the upper end of the drainage plate monomers of the third-level drainage system by a distance;

[0336] In the process of punching the first-level drainage system, the upper end of the prepared drainage monomer of the first-level drainage system is sealed and connected with the first-level drainage branch pipe with one end of the first-level drainage branch pipe facing upward, and the drainage plate monomers of the first-level drainage system are located between the drainage plate monomers of the second-level drainage system; when punching, the drainage plate monomers of the first-level drainage system are punched one by one according to the set spacing and the drainage plate monomer layout in the horizontal and vertical directions; the punching depth of the drainage plate monomers of the first-level drainage system overlaps the upper end of the drainage plate monomers of the second-level drainage system by a distance;

[0337] 3) Connect the drainage branch pipes of each level of drainage system with the corresponding water vapor separation bottles; connect the water vapor separation bottles of each level through the drainage main pipes with the corresponding vacuum negative pressure equipment or vacuum negative pressure station; and connect the drainage outlets of the water vapor separation bottles of each level with the drainage main pipe or drainage ditch through the drainage pipe;

[0338] 4) Arrange a data acquisition system, which includes a pressure acquisition device for acquiring vacuum pressure, a water level acquisition device for acquiring water level, a surface settlement acquisition device for acquiring surface settlement, and a target bottom sediment pore water pressure acquisition device;

[0339] 5) Lay woven cloth, geotextile, and sealing membrane on the working cushion in sequence, and extend the sealing membrane to the sealing ditch around; backfill sealing soil in the sealing ditch;

[0340] 6) Connect the drainage main pipes of each level of drainage system with the corresponding vacuum negative pressure equipment or vacuum negative pressure station respectively, turn on the vacuum negative pressure equipment, debug the vacuum negative pressure equipment, and detect whether there is air leakage; if there is air leakage, perform sealing repair treatment.

[0341] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application are within the scope of the technical solutions of the present application.

Claims

1. An ecological dredged sediment dewatering and drying system using warm pressure coupled thermal phase change, characterized in that, The application relates to a method for obtaining guiding parameters of target bottom mud. The method comprises the following steps of: a first obtaining part: obtaining target bottom mud; a second obtaining part: obtaining guiding parameters of the target bottom mud; first, extracting sample bottom mud from the target bottom mud, arranging a data acquisition module and a dehydration and drying part in the sample bottom mud, then carrying out a temperature-pressure coupling thermal phase change type dehydration and drying experiment on the sample bottom mud, collecting experimental data in the process of the experiment through the data acquisition module, wherein the experimental data comprises temperature, a permeability coefficient, a consolidation degree, a water discharge rate, a sedimentation rate and a pore water pressure change rate of the sample bottom mud, finally selecting experimental data meeting target requirements as the guiding parameters through analysis of the experimental data; the dehydration and drying part comprises a heating element, a drainage assembly and a vacuum pumping device; wherein: the analysis of the experimental data comprises the following steps of: analysis I: through analysis of the water discharge rate, the sedimentation rate, the pore water pressure change rate and the temperature of the sample bottom mud, the phase change point temperature of water in the sample bottom mud under different vacuum degrees is obtained; the specific analysis process under each vacuum degree is as follows: when the negative pressure is 80 KPA, the experiment of the consolidation degree comprises the following steps of: a first step: collecting the experimental data of the sample bottom mud under the condition of the negative pressure being 80 KPA; a second step: carrying out a polynomial fitting on the experimental data of the sample bottom mud under the condition of the negative pressure being 80 KPA; a third step: obtaining a second-order derivative function of the curve; a fourth step: obtaining a fourth-order polynomial fitting curve of the second-order derivative function; a fifth step: obtaining a fourth-order polynomial fitting expression of the fourth-order polynomial fitting curve; wherein: a0, a1, a2, a3 and a4 are all fitting coefficients; the fourth-order polynomial fitting specific steps are as follows: a fourth-order polynomial optimal solution is obtained by using a loss function Loss minimization, or the optimal solution is iteratively approached based on a gradient descent method; a laying part: arranging the data acquisition module and the dehydration and drying part in the target bottom mud; an information acquisition part: carrying out temperature-pressure coupling thermal phase change type dehydration and drying treatment on the target bottom mud by using the dehydration and drying part, and collecting state parameters of the target bottom mud in real time or at fixed time intervals in the process of the treatment; a control part: comparing the state parameters with the guiding parameters, selecting guiding parameters with minimum difference from the guiding parameters, and adjusting working condition parameters of the dehydration and drying part by using the guiding parameters; the guiding parameters comprise a heating temperature and a vacuum degree of the target bottom mud; when the guiding parameters select the phase change point temperature T under different vacuum degree conditions, the heating temperature is not higher than T+5; S501: obtaining the consolidation degree of the target bottom mud; S503: setting a most suitable temperature interval; when the temperature of the target bottom mud is higher than the temperature control interval, the heating element is turned off and the heating is stopped; when the temperature of the target bottom mud is lower than the temperature control interval, the heating element is turned on and the heating is started. The obtaining process of the first obtaining part is as follows: S101: determining a target area of ecological dredging bottom mud; S102: establishing an isolation belt around the target bottom mud in the target area, or transferring the target bottom mud in the target area to an isolation area; S103: arranging a covering sealing film on the target area. The obtaining process of the second obtaining part is as follows: S201: extracting single or M portions of sample bottom mud from the same position or different positions of the target bottom mud, M is a natural number greater than 1, and arranging the data acquisition module and the dehydration and drying part in each portion of the sample bottom mud. ​ When the vacuum degree is determined, the sample bottom mud is gradually warmed, and the temperature, water discharge rate, settlement rate, and pore water pressure change rate during the warming process are obtained. Finally, the temperature T at the water discharge rate mutation point is extracted w , the temperature T at the settlement rate mutation point s , and the temperature T at the pore water pressure change rate mutation point v . The maximum value of T v , T w , and T s is selected as the phase transition point temperature T. Analysis II, the most suitable drainage temperature Tz of the sample bottom mud under different consolidation degrees and the permeability coefficient under the most suitable drainage temperature Tz when the negative pressure condition is 80 KPA k max ; ​ S2-1, the permeability coefficient k of the test sample bottom mud in the temperature interval under the negative pressure condition i ; the temperature interval is T i (20, 60); S2-2, temperature t of the sample bottom mud i and the permeability coefficient k i polynomial fitting is performed four times; ​ ； ​ S2-3, obtain the optimal drainage temperature Tz by the curve z and the optimal permeability coefficient k at the optimal drainage temperature Tz max ; ​ ； where: t i is the temperature of the sample bottom mud; Let k" = 0; then the optimum drainage temperature T z is: ； The optimal permeability coefficient k corresponds to the optimal drainage temperature max is: ； ​ Establishing the consolidation degree U using a non-linear fitting method t In the lifting process, the optimal permeability coefficient k max The most suitable drainage temperature T z Change characteristic curve; Under different consolidation degrees U t , repeat sub S2-1 ~ S2-3, obtain the most suitable drainage temperature T max of the sample bottom mud with the optimal permeability coefficient k z under different consolidation states S2-5, in the consolidation degree U t In the growth process, the consolidation degree U t corresponding relationship with the optimal drainage temperature T z ; ​ ​ ​ ​ ​ When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal ​ The pore water pressure dissipation value Δus of the target bottom mud is calculated according to the pore water pressure i , and the consolidation degree U s of the target bottom mud is equal to the consolidation degree U t of the sample bottom mud. ； ； In the formula, P is the preloading of dewatering and drying; u s0 is the excess pore water pressure of the target sediment before dewatering and drying; S502, according to the target consolidation degree U of the bottom mud s , match the fitting data of the quartic polynomial fitting; Determine the soil state of the target bottom mud, associate the consolidation degree of the target bottom mud at the current time node with the consolidation degree of the sample bottom mud, and obtain the most suitable drainage temperature Tz of the sample bottom mud with the consolidation degree in the test and the corresponding optimal permeability coefficient k max ; ​ The optimal permeability coefficient k max The corresponding optimal drainage temperature T z , is set as the central value, the upward temperature float is 5, and the downward temperature float is 5, that is, the optimal temperature interval (T z min , T z max ) is (T z -5, T z +5); S504, maintaining the temperature of the target sediment within the optimum temperature range (T z min , T z max ) by controlling the temperature increasing device; specifically, ​ ​ 2. The eco-dredged sediment thermal phase change dewatering and drying system of claim 1, wherein, ​ ​ ​ ​ 3. The eco-dredged sediment thermal phase change dewatering and drying system of claim 1, wherein, ​ ​ S202, for each sample of bottom mud, a temperature-pressure coupling thermal phase change dehydration drying experiment is carried out, and experimental data are collected in real time or at regular time intervals during the experiment; S203, each experimental data is analyzed, and the experimental data meeting the target requirements are selected as the guiding parameters of the target bottom mud in the sampling point area corresponding to the experimental data.

4. The eco-dredged sediment thermal phase change dewatering and drying system of claim 1, wherein, The method for obtaining the phase transition point temperature T is: Step 1: Put the sample bottom mud into a sealed container and perform vacuum extraction; Step 2: When the average water discharge rate is less than 10g / h for 4-6h, gradually increase the temperature of the sample bottom mud by 5-10℃ each time; during the temperature increasing process: Measuring the sample bottom sediment water outflow rate, when the sample bottom sediment water outflow rate instantaneously increases by more than 10 times, recording the temperature at this time as T w ; Measuring the sample bottom mud settling rate, when the sample bottom mud settling rate instantaneously increases by more than 10 times, record the temperature at this time as T s ; The rate of change of pore water pressure is measured, and when the rate of change of pore water pressure instantaneously increases by more than 10 times, the temperature at this time is recorded as T v ; Step three: Select T w , the maximum value of T s and T v as the phase transition point temperature T.

5. The eco-dredged sediment thermal phase transition dewatering and drying system of claim 1, wherein, The data acquisition module includes an air pressure sensor for acquiring the vacuum degree under the membrane, a temperature sensor for acquiring the soil temperature, a pressure sensor for acquiring the pore water pressure, and an Internet of Things electric meter for monitoring the electric power consumption.

6. The eco-dredged sediment thermal phase change dewatering and drying system of claim 5, wherein, A proximal temperature sensor is arranged around each heating element, and the proximal temperature sensor is located at the same depth as the heating element; a distal temperature sensor is arranged between two adjacent heating elements, and the distance between the distal temperature sensor and the two heating elements is equal.

7. The eco-dredged sediment thermal phase change dewatering and drying system of claim 5, wherein, A proximal temperature sensor is arranged around each heating element, and L distal temperature sensors are arranged between two adjacent heating elements; when L is equal to 1, the distal temperature sensor is located at the same depth as the two heating elements; when L is greater than 1, the L distal temperature sensors are located at different depths.

8. The eco-dredged sediment thermal phase change dewatering and drying system of claim 1, wherein, The arrangement method of the heating element is: The heating element is buried: the heating element is placed at the bottom or middle of the drainage plate in a vertical form to the construction operation surface; The heating element includes a hollow columnar structure heating body, a heater is arranged in the interlayer of the heating body, the heater is connected with an external power supply through a wire, so that the inner cavity of the heating body forms a heating cavity, the upper and lower ends of the heating body are respectively provided with water-permeable and air-permeable stone materials for connecting the heating cavity with the outside, the inner cavity of the heating body is provided with a support rod, the upper and lower ends of the support rod respectively extend into the water-permeable and air-permeable stone materials, and a pressing portion is arranged at the lower end of the support rod and penetrates through the water-permeable and air-permeable stone materials; Release the heating body and connect the circuit; Under the action of temperature-pressure coupling, the water content of dredged bottom mud is reduced: when the conventional vacuum preloading drainage consolidation is carried out to the later stage, the heating body is powered on to heat the dredged bottom mud, and vacuum drainage is continued at the same time, by controlling the temperature of the heating body and the vacuum negative pressure of the dredged bottom mud, the water molecules in the dredged bottom mud are quickly converted from liquid to gas, and are discharged through the drainage plate, thereby reducing the water content of the dredged bottom mud; The heating body is controlled at a constant temperature.

9. The eco-dredged sediment thermal phase change dewatering and drying system of claim 1, wherein, The drainage assembly includes drainage plates and vacuum negative pressure equipment connected with drainage pipes.

10. The eco-dredged sediment thermal phase change dewatering and drying system of claim 9, wherein, The drainage plate is provided with at least P independent drainage systems, wherein P is a natural number greater than 1.

11. The eco-dredged sediment thermal phase change dewatering and drying system of claim 10, wherein, Each drainage system includes a plurality of drainage plate monomers arranged in the transverse and longitudinal directions of the target bottom mud, and the depths of the drainage plate monomers of the same level are the same; The drainage plate monomers of the lower level drainage system are arranged between the drainage plate monomers of the upper level drainage system, and the upper ends of the drainage plate monomers of the lower level drainage system overlap the lower ends of the drainage plate monomers of the upper level drainage system by a distance; The upper end of each drainage plate monomer of the primary drainage system is connected to a primary water-vapor separation bottle through a joint and a primary drainage branch pipe; The air outlet of the primary water-vapor separation bottle is connected to a primary vacuum negative pressure equipment through a primary air extraction main pipe, and the water outlet of the primary water-vapor separation bottle is connected to a drainage main pipe or a drainage ditch through a drainage pipe; In addition to the upper end of the drainage plate monomer of the primary drainage system being connected to a primary water-vapor separation bottle through a joint and a primary drainage branch pipe, the lower end of the drainage monomer of each subsequent drainage system is connected to a corresponding water-vapor separation bottle of the corresponding level through a joint and a corresponding drainage branch pipe of the corresponding level that is independent of each other; the air outlet of each water-vapor separation bottle is connected to a corresponding vacuum negative pressure equipment of the corresponding level through a corresponding air extraction main pipe of the corresponding level that is independently controlled; and the water outlet of each water-vapor separation bottle is connected to a drainage main pipe or a drainage ditch through a drainage pipe.

12. An ecological dredged sediment dewatering and drying method by warm pressure coupling thermal phase change, characterized in that, Comprise: S1, obtaining a target bottom mud; S2, obtaining guiding parameters of the target bottom mud: first, extracting a sample bottom mud from the target bottom mud, arranging a data acquisition module and a dehydration and drying component in the sample bottom mud, then performing a temperature and pressure coupled thermal phase change type dehydration and drying experiment on the sample bottom mud, collecting experimental data in the process of the experiment through the data acquisition module, the experimental data including temperature, permeability coefficient, degree of consolidation, water discharge rate, settlement rate and pore water pressure change rate of the sample bottom mud, and finally selecting experimental data meeting target requirements as the guiding parameters through analysis of the experimental data; the dehydration and drying component comprises a heating element, a drainage assembly and a vacuum extraction equipment; wherein: The analysis of the experimental data comprises: Analysis I: through analysis of the water discharge rate, settlement rate, pore water pressure change rate and temperature of the sample bottom mud, the phase change point temperature of water in the sample bottom mud under different vacuum degrees is obtained; the specific analysis process for each vacuum degree is as follows: When the vacuum degree is determined, the sample bottom mud is gradually warmed, and the temperature, water discharge rate, settlement rate, and pore water pressure change rate during the warming process are obtained. Finally, the temperature T at the water discharge rate mutation point is extracted w , the temperature T at the settlement rate mutation point s , the temperature T at the pore water pressure change rate mutation point v , and the maximum value of T v , T w , and T s is selected as the phase transition point temperature T. Analysis II, the most suitable drainage temperature Tz of the sample bottom mud under different consolidation degrees and the permeability coefficient under the most suitable drainage temperature Tz when the negative pressure condition is 80 KPA k max ; When the negative pressure condition is 80 KPA, the experiment of the degree of consolidation comprises: S2-1, the permeability coefficient k of the test sample bottom mud in the temperature interval under the negative pressure condition i ; the temperature interval is T i (20, 60); S2-2, temperature t of the sample bottom mud i and the permeability coefficient k i polynomial fitting is performed four times; The expression of the curve after the quartic polynomial fitting is as follows: ； In the formula, a0, a1, a2, a3 and a4 are all fitting coefficients; S2-3, obtain the optimal drainage temperature Tz by the curve z and the optimal permeability coefficient k at the optimal drainage temperature Tz max ; The second-order derivative function of the curve is as follows: ； where: t i is the temperature of the sample bottom mud; Let k" = 0; then the optimum drainage temperature T z is: ； The optimal permeability coefficient k corresponds to the optimal drainage temperature max is: ； S2-4, under the condition of stable pressure, the permeability coefficient of the sample bottom mud under different consolidation states is measured; Establishing the consolidation degree U using a non-linear fitting method t In the lifting process, the optimal permeability coefficient k max The optimal drainage temperature T z Variation characteristic curve; Under different consolidation degrees U t , repeat sub S2-1 ~ S2-3, obtain the most suitable drainage temperature T max of the sample bottom mud with the optimal permeability coefficient k z under different consolidation states; S2-5, in the consolidation degree U t In the growth process, the consolidation degree U t corresponding relationship with the optimal drainage temperature T z ; The specific steps of the quartic polynomial fitting are as follows: the quartic polynomial optimal solution is obtained by using loss function Loss minimization, or the optimal solution is iteratively approximated based on the gradient descent method; S3, arranging a data acquisition module and a dehydration and drying component in the target bottom mud; S4, performing temperature and pressure coupled thermal phase change type dehydration and drying treatment on the target bottom mud by using the dehydration and drying component, and collecting state parameters of the target bottom mud in real time or at regular intervals in the process of the treatment; S5, comparing the state parameters with the guiding parameters, selecting a guiding parameter with the least difference from the guiding parameters, and adjusting the working condition parameters of the dehydration and drying component by using the guiding parameter; the guiding parameters include heating temperature and vacuum degree of the target bottom mud; When the guiding parameter selects the corresponding phase change point temperature T under different vacuum degree conditions, the heating temperature is not greater than T+5; When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal drainage temperature T z When the guide parameter selects different consolidation degrees, the corresponding optimal S501, obtaining the degree of consolidation of the target bottom mud; The pore water pressure dissipation value Δus of the target bottom mud is calculated according to the pore water pressure i , and the consolidation degree U s of the target bottom mud is equal to the consolidation degree U t of the sample bottom mud. ； ； In the formula, P is the preloading of dewatering and drying; u s0 is the excess pore water pressure of the target sediment before dewatering and drying; S502, according to the target consolidation degree U of the bottom mud s , match the fitting data of the quartic polynomial fitting; Determine the soil state of the target bottom mud, associate the consolidation degree of the target bottom mud at the current time node with the consolidation degree of the sample bottom mud, and obtain the most suitable drainage temperature Tz of the sample bottom mud with the consolidation degree in the test and the corresponding optimal permeability coefficient k max ; S503, setting the most suitable temperature interval; The optimal permeability coefficient k max The corresponding optimal drainage temperature T z , is set as the central value, the upward temperature float is 5, and the downward temperature float is 5, that is, the optimal temperature interval (T z min , T z max ) is (T z -5, T z +5); S504, maintaining the temperature of the target sediment within the optimum temperature range (T z min , T z max ) by controlling the temperature increasing device; specifically, When the temperature of the target bottom mud is higher than the temperature control range, the heating element is turned off and the heating is stopped; When the temperature of the target bottom mud is lower than the temperature control range, the heating element is turned on and the heating is started.

13. The eco-dredged sediment thermal phase transition dewatering and drying method of claim 12, wherein, S1 is specifically: S101, determining the target area of the ecological dredged bottom mud; S102, establishing an isolation zone around the target bottom mud in the target area, or transferring the target bottom mud in the target area to an isolation zone; S103, setting a covering sealing film on the target area.

14. The eco-dredged sediment thermal phase transition dewatering and drying method of claim 12, wherein, S2 is specifically: S201, extracting a single or M portions of sample bottom mud from the same or different positions of the target bottom mud, M being a natural number greater than 1, and arranging a data collection module and a dehydration and drying component in each portion of sample bottom mud; S202, performing a temperature and pressure coupled thermal phase change type dehydration and drying experiment on each portion of sample bottom mud, and collecting experimental data in real time or at regular intervals during the experiment; S203, analyzing each portion of experimental data, and selecting experimental data meeting target requirements as guiding parameters of the target bottom mud in the sampling point area corresponding to the experimental data.

15. The eco-dredged pond sludge thermocouple dehydration method according to claim 12, characterized in that, The method for obtaining the phase transition point temperature T is: Step one: place the sample bottom mud in a sealed container and perform vacuum extraction; Step two: when the average water discharge rate is less than 10 g / h for 4-6 consecutive hours, gradually increase the temperature of the sample bottom mud by 5-10°C each time; during the temperature increasing process: Measuring the sample bottom sediment water outflow rate, when the sample bottom sediment water outflow rate instantaneously increases by more than 10 times, recording the temperature at this time as T w ; Measuring the sample bottom mud settling rate, when the sample bottom mud settling rate instantaneously increases by more than 10 times, record the temperature at this time as T s ; The rate of change of pore water pressure is measured, and when the rate of change of pore water pressure instantaneously increases by more than 10 times, the temperature at this time is recorded as T v ; Step three: Select T w , the maximum value of T s , and T v as the phase transition point temperature T.

16. The eco-dredged pond sludge thermally induced phase transition type dewatering and drying method according to claim 12, characterized by, The arrangement method of the heating element is: The heating element is buried: the heating element is placed at the bottom or middle of the drainage plate in a form perpendicular to the construction operation surface; The heating element includes a hollow columnar structure heating body, a heater is arranged in the interlayer of the heating body, the heater is connected with an external power supply through a wire, so that the inner cavity of the heating body forms a heating cavity, water-permeable and air-permeable stone materials are arranged at the upper and lower ends of the heating body respectively for connecting the heating cavity with the outside, a support rod is arranged in the inner cavity of the heating body, the upper and lower ends of the support rod extend into the water-permeable and air-permeable stone materials respectively, and a pressing portion is arranged at the lower end of the support rod and penetrates through the water-permeable and air-permeable stone materials; Release the heating body and connect the circuit; Under the action of temperature and pressure coupling, the water content of the dredged bottom mud is reduced: when the conventional vacuum preloading drainage consolidation is carried out to the later stage, the heating body is powered on to heat the dredged bottom mud, and vacuum extraction is continued at the same time, by controlling the temperature of the heating body and the vacuum negative pressure of the dredged bottom mud, the water molecules in the dredged bottom mud are quickly converted from liquid to gas, and are discharged through the drainage plate, thereby reducing the water content of the dredged bottom mud; S4, constant temperature control of the heating body.

17. The eco-dredged pond sludge thermally induced phase transition type dewatering and drying method according to claim 12, characterized by, The drainage assembly includes drainage plates and a drainage pipe connected with a vacuum negative pressure device; the drainage plates are provided with at least P independent drainage systems, where P is a natural number greater than 1.

18. The eco-dredged sediment thermal phase transition dewatering and drying method of claim 17, wherein, When P is equal to 3, the arrangement method of the three independent drainage systems is: 1) determine the depth of each level of drainage plate system and the length of each drainage plate monomer in each level of drainage system according to the depth of the target bottom mud; 2) first, set the drainage plate monomers of the deepest third-level drainage system, then set the second-level drainage system in turn, and finally set the first-level drainage system. In the three-level drainage system, the lower end of the prepared drainage monomer of the three-level drainage system is connected to the three-level drainage branch pipe through a sealing clamp, and the end of the three-level drainage branch pipe is downward; the drainage monomers of the three-level drainage system are arranged according to the set spacing and the drainage monomer arrangement map; In the two-level drainage system, the lower end of the prepared drainage monomer of the two-level drainage system is connected to the two-level drainage branch pipe through a sealing clamp, and the end of the two-level drainage branch pipe is downward, and the drainage monomers of the two-level drainage system are located between the drainage monomers of the P-level drainage system; the drainage monomers of the two-level drainage system are arranged according to the set spacing and the drainage monomer arrangement map; In the one-level drainage system, the upper end of the prepared drainage monomer of the one-level drainage system is connected to the one-level drainage branch pipe, and the end of the one-level drainage branch pipe is upward, and the drainage monomers of the one-level drainage system are located between the drainage monomers of the two-level drainage system; the drainage monomers of the one-level drainage system are arranged according to the set spacing and the drainage monomer arrangement map; 3) Connect the drainage branch pipe of each level of drainage system to the corresponding water vapor separation bottle, and connect the water vapor separation bottle of each level to the corresponding vacuum negative pressure equipment or vacuum negative pressure station through the drainage main pipe, and connect the drainage port of each level of water vapor separation bottle to the drainage main pipe or drainage ditch through the drainage pipe; 4) Arrange a data acquisition system, which includes a pressure acquisition device for acquiring vacuum pressure, a water level acquisition device for acquiring water level, a surface settlement acquisition device for acquiring surface settlement, and a target bottom mud pore water pressure acquisition device for acquiring target bottom mud pore water pressure; 5) Pile up woven cloth, geotextile and sealing film on the working cushion layer in sequence, and extend the sealing film to the sealing ditch around, and backfill sealing soil in the sealing ditch; 6) Connect the drainage main pipe of each level of drainage system to the corresponding vacuum negative pressure equipment or vacuum negative pressure station, open the vacuum negative pressure equipment, debug the vacuum negative pressure equipment, and detect whether there is air leakage. If there is air leakage, seal and repair the leakage.

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