CN104713904A - Calculating method and detection device of seafloor in-situ thermal conductivity - Google Patents

Abstract

The invention provides a calculating method and a detection device of seafloor in-situ thermal conductivity, and belongs to the technical field of seafloor in-situ heat flow detection. The calculating method comprises the following steps: detecting gestures and moving conditions of a probe in the sea floor by using a gesture detection module, and then controlling a heat pulse control module to excite heat pulses by using a main control module to perform electric heating on heating wires of the probe at the front end of a measuring unit; synchronously, controlling a temperature acquisition module to acquire temperature data of submarine sediments by using the main control module, and then outputting the temperature data to a PC machine; and establishing a finite element TC_FE numerical model by virtue of the PC machine, and performing parameter inversion by using a mesh encryption search method. According to the calculating method and the detection device of the seafloor in-situ thermal conductivity provided by the invention, by adopting the gesture detection module, the seafloor arrival conditions can be judged and automatic heat pulse control can be performed; meanwhile, the in-situ environment temperature and in-situ thermal conductivity of the submarine sediments can be acquired, and the offshore operation safety and seafloor detection efficiency can also be greatly improved; and by establishing an in-situ thermal conductivity numerical inversion method, the limitation of analytical solutions of a simplified model depended by in-situ thermal conductivity solution can be eliminated.

Description

The calculation method of a kind of seabed in-situ heat conductance and sniffer thereof

Technical field

The invention belongs to original position hot-fluid Detection Techniques field, seabed, particularly the calculation method of a kind of seabed in-situ heat conductance and sniffer thereof.

Background technology

Geothermy, as an important branch of geophysics subject, is the subject that a basic and application is all very strong, and terrestrial heat flow measurements is the most basic means obtaining earth's temperature regime parameter, is also the link of most critical during geothermy is studied.The main source of oceanic heat flow parameter is Digitalisation data (as oil and deep sea drilling boring) and oceanic heat flow probe measurement.Early 1980s, many scholars utilized the Bottom-simulating reflection face (BSR) of disclosing in natural gas hydrate exploration to estimate oceanic heat flow so far.Because oil boring is mainly positioned at shoal water zone (being no more than on the continental platform of 200m as China's south sea petroleum boring is mainly positioned at the depth of water), although deep sea drilling boring is in deepwater regions, but erect-position quantity is little, and the oceanic heat flow data estimated by BSR exist more uncertain factor.It can thus be appreciated that the detection of probe-type oceanic heat flow becomes the Main Means of profundal zone and the investigation of ocean basin floor oceanic heat flow, and the developing direction that probe-type Detection Techniques also will be oceanic heat flow Detection Techniques.

As far back as the 1950's, researcher utilizes the Bullard type geothermal probe of design successfully to carry out geothermal measurement in marine site, the North Atlantic Ocean, opens the epoch of oceanic heat flow investigation.Along with improving and the progress of technical method of thermal measurement theory, and the progress of computer technology and large scale integrated circuit technology and memory technology and popularization and application, through the development of nearly over half a century, oceanic heat flow probe Detection Techniques are also developed rapidly.Current more ripe in the world and the oceanic heat flow probe be widely used can be divided into Ewing type (as shown in Figure 1) and Lister type (as shown in Figure 2) two class.As shown in Figure 1, traditional Ewing type probe is equidistant for the measuring unit 2 that temperature-sensing element 1 the is housed spiral outer diverse location hanging over stopple coupon 3, can only realize the original position ground temperature gradiometry of marine bottom sediment, thermal conductivity needs to carry out independent measurement acquisition in indoor to the sediment sample gathered; During owing to gathering sediment sample, sample original structure and water cut inevitably to some extent destroy and environment temperature, pressure condition change and cause institute's calorimetric conductance error larger, therefore, the sediment thermal conductivity that laboratory records generally all needs to carry out temperature, pressure and water cut and corrects.It can thus be appreciated that, although traditional Ewing type probe has the advantage of Measuring Time shorter (about 8 minutes), can not directly obtain in-situ heat conductance, in fact just a kind of underground temperature gradient probe.Lister type probe adopts thermal pulse technology, theoretical model is simplified based on the unlimited long column thermal source (IICS) of transient heating, process frictional heat and thermal pulse heat two stage Temperature-time data to solve underground temperature gradient and in-situ heat conductance, achieve the measurement of pulsed original position hot-fluid.As shown in Figure 2, the probe of the type is also referred to as " bow " type probe, in its tubule 4, heater strip 5 is installed, equally spaced arrangement multiple (or group) temperature-sensing element 1 simultaneously, keep at a certain distance away and be fixed on thick firm steel lance 6, but Lister type probe comparatively thick (radius generally reaches 5.0mm), theoretical model is simplified for meeting IICS as far as possible, after requiring PULSE HEATING, probe needs static stop 25 minutes even longer in sediment, to measure sufficiently long temperature damping's data to be used for calculating reliable original position underground temperature gradient and in-situ heat conductance, thus obtain in-situ heat flow data accurately.Therefore, compared with Ewing type probe, the habitata efficiency of Lister type heat flow probe is relatively low, and the sea situation when dynamically positioning ability of operation ship and operation is required harsh especially, once operation ship departs from probe, to insert sedimental position far away, probe rises and to be easy to be pulled out curved when pulling out, and cause probe impaired, this just increases offshore operation risk to a great extent.

In sum, all kinds of probes used in the world at present all also exist weak point in actual oceanic heat flow measuring process.

Summary of the invention

For the deficiencies in the prior art, the object of the invention is to consider from the singularity of oceanic heat flow detection, the security of marine actual job, high efficiency and convenience, calculation method and the sniffer thereof of a kind of seabed in-situ heat conductance are provided, overcome Ewing type probe and directly can not measure in-situ heat conductance and the Lister type probe measurement time longer deficiency being unfavorable for offshore operations, be convenient to offshore operation, simultaneously can also within a short period of time accurately and safety detection seabed in-situ heat conductance.

For achieving the above object, the present invention takes following technical scheme: the calculation method of a kind of seabed in-situ heat conductance, comprises the following steps:

(1) by the attitude of attitude detection module detector probe in seabed and motion conditions, when judging that probe inserts and is still in marine bottom sediment, master control module controls thermal pulse control module excites thermal pulse to carry out electrical heating to the heater strip of measuring unit front-end probe;

(2) temperature collect module be electrically connected with probe by master control module controls carries out marine bottom sediment temperature data acquisition;

(3) main control module carries out from holding process to temperature data;

(4) be connected with the communication between optimum configurations with data reader by measuring unit from the data held and output to PC;

(5) set up finite element TC_FE numerical model by PC, adopt mesh refinement search procedure to carry out parametric inversion, step is as follows:

1) marine bottom sediment is established to look thermal conductivity λ ₂₁(λ ₂₁for marine bottom sediment thermal conductivity λ and measuring unit front-end probe volumetric heat capacity C ₁ratio, i.e. λ/C ₁) and marine bottom sediment apparent volume thermal capacitance C ₂₁(C ₂₁for marine bottom sediment volumetric heat capacity C and measuring unit front-end probe volumetric heat capacity C ₁ratio, i.e. C/C ₁), to domain

$\left\{\begin{array}{c}{\mathrm{\λ}}_{21}\∈[1.0\×{10}^{-7}{m}^2\·s^{-1},2.0\×{10}^{-6}{m}^2\·s^{-1}]\\ C_{21}\∈\left[\mathrm{0.1,4.0}\right]\end{array}\right.$ Middle two parameter all carries out m equal portions subdivision, obtains the individual grid node of initial (m+1) × (m+1) wherein i, j=1,2, Λ, m;

2) λ is got ₁₁=1.0 × 10 ^-4m ²s ^-1, utilize TC_FE model to calculate time, the T-t temperature data of measuring unit front-end probe top end, is designated as wherein λ ₁₁for measuring unit front-end probe equivalent thermal conductivity λ ₁with its equivalent volume thermal capacitance C ₁ratio, namely because theoretical research shows, λ ₁₁change on inversion result impact very little, can ignore, therefore can according to the experience thermal conductivity of measuring unit front-end probe rapidoprint, volumetric specific heat capacity and thermal diffusivity variation range value, value λ ₁₁=1.0 × 10 ^-4m ²s ^-1.

3) finite element analogy acquisition is carried out by PC ((T is designated as with the T-t temperature data that probe is surveyed in marine bottom sediment _meas, t _n)) be normalized, obtain normalization std.T-t data:

${\mathrm{std}.T}_{\mathrm{mod}}^{i,j}\left(t_n\right)=\frac{T_{\mathrm{mod}}^{i,j}\left(t_n\right)}{\mathrm{Max}\left\{T_{\mathrm{mod}}^{i,j}\left(t_n\right)\right\}},$

${\mathrm{std}.T}_{\mathrm{meas}}\left(t_n\right)=\frac{[T_{\mathrm{meas}}\left(t_n\right)-T_{\mathrm{meas}}\left(0\right)]}{\mathrm{Max}\{T_{\mathrm{meas}}\left(t_n\right)-T_{\mathrm{meas}}\left(0\right)\}};$

4) least square method is utilized, right with std.T _meas(t _n) carry out linear fit and draw:

${\mathrm{std}.T}_{\mathrm{meas}}\left(t_n\right)=K_1^{i,j}\·\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_n\right),$

Solve this fitting a straight line slope and coefficient R ^i,j, wherein Calculation of correlation factor expression formula is as follows

$R^{i,j}=\frac{n\underset{k=1}{\overset{n}{\mathrm{\Σ}}}(\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right)\·{\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right))-\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right)\right)\·\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right)\right)}{\sqrt{[n\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\left({\mathrm{std}.T}_{\mathrm{mod}}^{i,j}\left(t_k\right)\right)}^2-{\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{std}.T}_{\mathrm{mod}}^{i,j}\left(t_k\right)\right)}^2\·[n\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\left({\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right)\right)}^2-{\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right)\right)}^2]}};$

5) objective definition function is and solve the target function value at each net point place i, j=1,2, Λ, m;

6) net point that target function value is minimum is found out, $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})=\min \left\{F({\mathrm{\&lambda;}}_{21}^i,C_{21}^j)\right\},$ If $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})<\mathrm{\&epsiv;}$ (ε judges whether to meet the threshold value solving and require to set), then accept for the required marine bottom sediment solved looks thermal physical property parameter (λ ₂₁, C ₂₁), otherwise, will be with centered by neighborhood be domain, by mesh refinement, turn back to step 2), until meet for this reason, thus resolve and obtain marine bottom sediment and look thermal physical property parameter

7) again least square method is utilized, right with T _meas(t _n) carry out linear fit:

marine bottom sediment environment temperature T is recorded according to temperature collect module ₀, solve its fitting a straight line slope with wherein

$K_2^{i,j}=\frac{H_{0\_\mathrm{meas}}}{H_{0\_\mathrm{mod}}}=\frac{A_{0\_\mathrm{meas}}/C_1}{A_{0\_\mathrm{mod}}/C_1},$

Measuring unit front-end probe volume heat generation rate A is obtained according to the PULSE HEATING Current calculation that step (1) records _{0_meas}, the apparent volume heat generation rate H of probe is drawn according to TC_FE model _{0_mod}=A _{0_mod}/ C ₁, the volumetric heat capacity obtaining popping one's head in can be solved thus

$C_1=\frac{A_{0\_\mathrm{meas}}}{K_2^{i,j}\&CenterDot;[A_{0\_\mathrm{mod}}/C_1]}=\frac{A_{0\_\mathrm{meas}}}{K_2^{i,j}\&CenterDot;H_{0\_\mathrm{mod}}},$

Again according to λ=λ ₂₁c ₁marine bottom sediment thermal conductivity λ can be solved.

A kind of sniffer implementing above-mentioned calculation method, comprise front-end probe, probe internally provided temperature-sensing element and heater strip, also comprise main control module, temperature collect module, attitude detection module and thermal pulse control module, main control module is by microprocessor, communication interface circuit, real-time clock, storer and DC constant voltage electric power generating composition, communication interface circuit, real-time clock, storer, DC constant voltage power supply are corresponding with microprocessor to be respectively electrically connected, and communication interface circuit is connected with data reader communication by measuring unit shell; Temperature collect module is made up of constant-current source circuit, temperature signal regulation circuit and temperature detecting resistance bridge, constant-current source circuit, temperature signal regulation circuit, thermistor are corresponding with temperature detecting resistance bridge to be respectively electrically connected, and temperature signal regulation circuit is corresponding with microprocessor to be electrically connected; Attitude detection module is made up of attitude signal modulate circuit and attitude sensor, and attitude sensor is electrically connected with attitude signal modulate circuit, and attitude signal modulate circuit is corresponding with microprocessor to be electrically connected; Thermal pulse control module is made up of DC constant flowing power and pulsed triggering circuit, and DC constant flowing power, heater strip are electrically connected with pulsed triggering circuit respectively, and DC constant flowing power is corresponding with microprocessor to be electrically connected.

Main control module carries out cooperation control to whole sniffer, main control module can control temperature acquisition module whole detection process and sniffer are transferred in the seawater, insert marine bottom sediment after friction Temperature Rise and heat fade process, thermal pulse start after temperature rise and heat fade process and the whole process that is recycled to scientific investigation boat deck after extracting marine bottom sediment in the seawater carry out temperature acquisition.Main control module can also control the attitude of attitude detection module monitors probe in seabed operation process and motion conditions, and control thermal pulse control module and excite thermal pulse to carry out electrified regulation to measuring unit front end heater strip, concrete temperature sensing process is as follows: DC constant voltage electric current is that measuring unit is powered, the real-time clock log time, storer is for depositing program and data; Heat flow probe is being transferred in the process in seabed from operation ship, and attitude detection module and temperature collect module start collecting work in the moment set, and keep low-frequency sampling; Microprocessor is by the attitude of attitude detection module-monitoring heat flow probe in seabed operation process and motion conditions, when judging that probe inserts and is still in marine bottom sediment, microprocessor start-up temperature acquisition module enters high frequency sample phase, records the temperature rise curve caused because of measuring unit head temperature sensor probe and marine bottom sediment friction; The heat of friction of setting terminates rear (being generally a few minutes) writing time, and microprocessor starting impulse trigger circuit provide constant heating current to heater strip, simultaneously by temperature collect module record temperature variation curve; All data and the temporal information of record are all kept in storage chip; After the heat time set terminates, microprocessor stops heating, and continuous high frequency sampling terminated to the high frequency sampling time set; After this measuring unit enters low-frequency sampling pattern, and heat flow probe is recycled to operation ship simultaneously.Measuring unit leaves after the water surface enters deck, and special data reader carries out data read operation by connecting measuring unit shell, and the data of acquisition are transferred to PC further and carry out heat flow data process and resolve.

Innovative point of the present invention is: not only possessed the advantage in Ewing type oceanic heat flow probe, measuring unit structure being convenient to offshore operation, and because adding heater strip in its front-end probe, determine end situation by attitude detection module and carry out thermal pulse control, thus also having possessed automatic heating pulse function, the in-situ heat conductance numerical simulation inversion method that the temperature data after its thermal pulse just can be used for proposing in the present invention resolves.Therefore the present invention can obtain marine bottom sediment underground temperature gradient and in-situ heat conductance and original position hot-fluid simultaneously, and greatly can improve security and the habitata efficiency of offshore operation; By setting up in-situ heat conductance numerical inversion model, break away from the limitation that in-situ heat conductance solves relied on simplified model analytic solution.

Accompanying drawing explanation

Fig. 1 is Ewing type oceanic heat flow meter schematic diagram;

Fig. 2 is Lister type oceanic heat flow meter schematic diagram;

Fig. 3 is measuring unit structural representation in the in-situ heat conductance sniffer of seabed;

Fig. 4 is the control principle block diagram of seabed in-situ heat conductance sniffer;

Fig. 5 is seabed in-situ heat conductance calculation method process flow diagram;

Fig. 6 is the temperature data curve map that seabed in-situ heat conductance sniffer is surveyed at erect-position Ind2012HF12.

Embodiment

Below in conjunction with drawings and Examples, content of the present invention is described further.

As shown in Figure 3, a kind of apparatus and method being applied to seabed in-situ heat conductance and measuring, comprise watertight pressure-resistant bin body, main control module, temperature collect module, attitude detection module, thermal pulse control module, and in-situ heat conductance the Method for Numerical Inversion.

Described watertight pressure-resistant bin body, comprises battery compartment 1, spring assembly 2, battery 3, brass electrode 4, insulation sleeve 5, urceolus 6, circuit board 7, nut 8, inner shield ring 9, joint 10, outer back-up ring 11, end cap 12, probe 13, O type circle 14, O type circle 15, O type circle 16, pad 17 and O type circle 18 and forms.

Battery compartment 1 comprises spring assembly 2, brass electrode 4, battery 3 and insulation sleeve 5.Insulation sleeve 5 keeps apart brass electrode 4 and urceolus 6, prevents battery 3 and urceolus 6 short circuit.

Battery compartment 1 and urceolus 6 are threaded, and are wherein provided with O type circle 18 between battery compartment 1 and urceolus 6 for axial watertight.

Probe 13, end cap 12, outer back-up ring 11, joint 10, inner shield ring 9, be fastenedly connected successively by nut 8, wherein pop one's head between 13 and end cap 12 and O type circle 14 is installed for axial watertight, O type circle 15 is installed for axial watertight between end cap 12 and outer back-up ring 11.

Urceolus 6 and joint 10 are threaded connection, and are wherein provided with O type circle 16 between urceolus 6 and joint 10 for axial watertight.

It is inner that circuit board 7 is arranged on urceolus 6, is connected by screw one end with nut 8, is wherein provided with pad 17, for insulating between the installation end of circuit board 7 and the installation end of nut 8.

The external diameter of battery compartment 1 and urceolus 6 is 30mm, and measuring unit total length is 200mm.Probe diameter is 5mm, and probe length is 40mm.

Whole watertight pressure-resistant bin body adopts the processing of 316L stainless steel.

Described watertight pressure-resistant bin body forms primarily of serial connections such as battery compartment, urceolus, copper rod, probe storehouse, insulation sleeves.

Described battery compartment comprises battery compartment shell, negative spring compounded plate, anode brass core and battery composition, for whole equipment is powered.Insulation sleeve keeps apart brass anode and shell, make battery electrode not with housing contacts.

Described copper rod diameter (2a) is designed to 3-8mm, and it, built with temperature sensor (platinum thermal resistance or thermistor), detects temperature.Be contained in measuring unit front-end probe storehouse.

Described probe storehouse length (L) is 30-50mm, and storehouse is built with copper rod assembly.

The pressurized capsule of battery compartment and urceolus composition, its external diameter (φ c) is 20-50mm, and (Lc) length is about 190-300mm.Battery compartment and urceolus use helicitic texture to be connected.

The in succession joint nut of end cap and urceolus of copper rod couples together, and adopts O RunddichtringO to carry out axial watertight.End cap is connected with urceolus, carries out axial watertight between the two with O RunddichtringO.O RunddichtringO is had to carry out axial watertight during joint is connected with urceolus.O RunddichtringO is had, for axial watertight between copper rod and end cap.

The metal parts of watertight pressure-resistant bin body adopts 316L stainless steel or TA10 titanic alloy machining to form.

The sealing of watertight pressure-resistant bin body all uses O RunddichtringO, and footpath, cross section is 3mm.

Described main control module, temperature collect module, attitude detection and thermal pulse control module are installed on watertight pressure-resistant bin body inside.

A calculation method for seabed in-situ heat conductance, comprises the following steps:

(1) by the attitude of attitude monitoring module monitors probe in seabed and motion conditions, when judging that probe inserts and is still in marine bottom sediment after 7-10 minute, master control module controls thermal pulse control module excites thermal pulse to carry out electrical heating to the heater strip in measuring unit front-end probe;

Lister type probe has a tubule that 4-6 rice is long, 10cm is thick usually.In tubule, heater strip is installed, simultaneously equally spaced arrangement multiple (or group) thermistor, keeps at a certain distance away and be fixed on thick firm steel lance.Its operating feature is as follows: after probe inserts and stablizes and be still in marine bottom sediment, first measure the intensification that causes of heat of friction and attenuation process afterwards thereof, after heat of friction decayed substantially, restart thermal pulse, PULSE HEATING time general 10-20 second, then stop heating.The temperature of the intensification that PULSE HEATING causes and heat fade process afterwards thereof equally also goes on record.Therefore Lister type probe is reduced to transient heating unlimited long column thermal source (IICS) model usually, then processes measured temperature data according to the analytic solution of its correspondence thus obtains in-situ heat conductance and hot-fluid parameter.

(2) temperature collect module be connected with measuring unit by master control module controls carries out marine bottom sediment temperature data acquisition;

(3) main control module carries out from holding process to temperature data;

(4) be connected with the communication between optimum configurations with data reader by measuring unit from the data held and output to PC;

Optimum configurations and data reader are a set of independently integrated circuit, are exclusively used in and carry out the operation such as optimum configurations and digital independent to measuring unit.Communication between them is by serial communication, is not USB.After data reader reads data from measuring unit, then send data to PC by USB communication.

From appearance process be exactly the underwater work of measuring unit all by microprocessor from main control, do not need On-line Control or manual control, self-tolerant work refer to one operation or gatherer process in robotization mode, show that equipment is autonomous manipulation.

Probe refers to a whole set of oceanic heat flow detection system (being also commonly called as oceanic heat flow probe), and plug-in on heat flow probe support bar is measuring unit, and measuring unit front end syringe needle (being built-in with temperature-sensing element and heater strip) is called front-end probe.

Need first to download to PC from the data held, the finite element numerical model (TC_FE) then set up by FEPG software is carried out thermal conductivity numerical inversion and is resolved.This intermediate demand uses data reader by data relay, instead of measuring unit is directly by data importing PC.

(5) by the finite element TC_FE numerical model that PC is set up, adopt mesh refinement search procedure to carry out parametric inversion, step is as follows:

Before carrying out in-situ heat conductance numerical inversion, for the feature of this problem, carry out parameter normalization, sensitivity and extreme value analysis, find that this problem can be described as the Parametric optimization problem of band boundary constraint, and the parameter of required Optimization Solution has only had sediment to look thermal conductivity (λ ₂₁, be sediment thermal conductivity λ and probe volume thermal capacitance C ₁ratio, i.e. λ/C ₁) and sediment apparent volume thermal capacitance (C ₂₁, be volume of sediment thermal capacitance C and probe volume thermal capacitance C ₁ratio, i.e. C/C ₁).To this, adopt mesh refinement search procedure to carry out parametric inversion, concrete steps overview is as follows:

Step.01: establish marine bottom sediment to look thermal conductivity λ ₂₁(λ ₂₁for marine bottom sediment thermal conductivity λ and measuring unit front-end probe volumetric heat capacity C ₁ratio, i.e. λ/C ₁) and marine bottom sediment apparent volume thermal capacitance C ₂₁(C ₂₁for marine bottom sediment volumetric heat capacity C and measuring unit front-end probe volumetric heat capacity C ₁ratio, i.e. C/C ₁), to domain

$\left\{\begin{array}{c}{\mathrm{\&lambda;}}_{21}\&Element;[1.0\&times;{10}^{-7}{m}^2\&CenterDot;s^{-1},2.0\&times;{10}^{-6}{m}^2\&CenterDot;s^{-1}]\\ C_{21}\&Element;\left[\mathrm{0.1,4.0}\right]\end{array}\right.$ Middle two parameter all carries out m equal portions subdivision, obtains the individual grid node of initial (m+1) × (m+1) wherein i, j=1,2, Λ, m;

Step.02: get λ ₁₁=1.0 × 10 ^-4m ²s ^-1, utilize TC_FE model to calculate time, the T-t temperature data of measuring unit front-end probe top end, is designated as wherein λ ₁₁for measuring unit front-end probe equivalent thermal conductivity λ ₁with its equivalent volume thermal capacitance C ₁ratio, namely because theoretical research shows, λ ₁₁change on inversion result impact very little, can ignore, therefore can according to the experience thermal conductivity of measuring unit front-end probe rapidoprint, volumetric specific heat capacity and thermal diffusivity variation range value, value λ ₁₁=1.0 × 10 ^-4m ²s ^-1.

Step.03: carry out finite element analogy acquisition by PC ((T is designated as with the T-t temperature data that probe is surveyed in marine bottom sediment _meas, t _n)) be normalized, obtain normalization std.T-t data:

${\mathrm{std}.T}_{\mathrm{mod}}^{i,j}\left(t_n\right)=\frac{T_{\mathrm{mod}}^{i,j}\left(t_n\right)}{\mathrm{Max}\left\{T_{\mathrm{mod}}^{i,j}\left(t_n\right)\right\}},$

${\mathrm{std}.T}_{\mathrm{meas}}\left(t_n\right)=\frac{[T_{\mathrm{meas}}\left(t_n\right)-T_{\mathrm{meas}}\left(0\right)]}{\mathrm{Max}\{T_{\mathrm{meas}}\left(t_n\right)-T_{\mathrm{meas}}\left(0\right)\}};$

Step.04: utilize least square method is right with std.T _meas(t _n) carry out linear fit and draw:

${\mathrm{std}.T}_{\mathrm{meas}}\left(t_n\right)=K_1^{i,j}\&CenterDot;\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_n\right),$

Solve this fitting a straight line slope and coefficient R ^i,j, wherein Calculation of correlation factor expression formula is as follows

$R^{i,j}=\frac{n\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}(\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right)\&CenterDot;{\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right))-\left(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right)\right)\&CenterDot;\left(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right)\right)}{\sqrt{[n\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{\left({\mathrm{std}.T}_{\mathrm{mod}}^{i,j}\left(t_k\right)\right)}^2-{\left(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{std}.T}_{\mathrm{mod}}^{i,j}\left(t_k\right)\right)}^2\&CenterDot;[n\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{\left({\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right)\right)}^2-{\left(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{std}.T}_{\mathrm{meas}}\left(t_k\right)\right)}^2]}};$

Step.05: objective definition function is and solve the target function value at each net point place i, j=1,2, Λ, m;

Step.06: find out the net point that target function value is minimum, $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})=\min \left\{F({\mathrm{\&lambda;}}_{21}^i,C_{21}^j)\right\},$ If $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})<$ $\mathrm{\&epsiv;}$ (ε judges whether to meet the threshold value solving and require to set), then accept for the required marine bottom sediment solved looks thermal physical property parameter (λ ₂₁, C ₂₁), otherwise, will be with centered by neighborhood be domain, by mesh refinement, turn back to step 2), until meet for this reason, thus resolve and obtain marine bottom sediment and look thermal physical property parameter $({\mathrm{\&lambda;}}_{21},C_{21})=({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0});$

Step.07: again utilize least square method is right with T _meas(t _n) carry out linear fit:

marine bottom sediment environment temperature T is recorded according to temperature collect module ₀, solve its fitting a straight line slope with wherein

$K_2^{i,j}=\frac{H_{0\_\mathrm{meas}}}{H_{0\_\mathrm{mod}}}=\frac{A_{0\_\mathrm{meas}}/C_1}{A_{0\_\mathrm{mod}}/C_1},$

Measuring unit front-end probe volume heat generation rate A is obtained according to the PULSE HEATING Current calculation recorded _{0_meas}, the apparent volume heat generation rate H of probe is drawn according to TC_FE model _{0_mod}=A _{0_mod}/ C ₁, the volumetric heat capacity obtaining popping one's head in can be solved thus

$C_1=\frac{A_{0\_\mathrm{meas}}}{K_2^{i,j}\&CenterDot;[A_{0\_\mathrm{mod}}/C_1]}=\frac{A_{0\_\mathrm{meas}}}{K_2^{i,j}\&CenterDot;H_{0\_\mathrm{mod}}},$

Again according to λ=λ ₂₁c ₁marine bottom sediment thermal conductivity λ can be solved.

Again because λ ₁=λ ₁₁c ₁, λ=λ ₂₁c ₁, C=C ₂₁c ₁, then can solve actual probe thermal conductivity accordingly, sediment thermal conductivity and volumetric heat capacity, arrive this, and probe and sedimental thermal physical property parameter have solved complete all.

A kind of sniffer implementing above-mentioned calculation method, comprise front-end probe, probe internally provided temperature-sensing element and heater strip, also comprise main control module, temperature collect module, attitude detection module and thermal pulse control module, main control module is by microprocessor, communication interface circuit, real-time clock, storer and DC constant voltage electric power generating composition, communication interface circuit, real-time clock, storer, DC constant voltage power supply are corresponding with microprocessor to be respectively electrically connected, and communication interface circuit is connected with data reader communication by measuring unit shell; Temperature collect module is made up of constant-current source circuit, temperature signal regulation circuit and temperature detecting resistance bridge, constant-current source circuit, temperature signal regulation circuit, thermistor are corresponding with temperature detecting resistance bridge to be respectively electrically connected, and temperature signal regulation circuit is corresponding with microprocessor to be electrically connected; Attitude detection module is made up of attitude signal modulate circuit and attitude sensor, and attitude sensor is electrically connected with attitude signal modulate circuit, and attitude signal modulate circuit is corresponding with microprocessor to be electrically connected; Thermal pulse control module is made up of DC constant flowing power and pulsed triggering circuit, and DC constant flowing power, heater strip are electrically connected with pulsed triggering circuit respectively, and DC constant flowing power is corresponding with microprocessor to be electrically connected.

Concrete temperature sensing process is as follows: DC constant voltage electric current is that measuring unit is powered, the real-time clock log time, storer is for depositing program and data; Heat flow probe is being transferred in the process in seabed from operation ship, and attitude detection module and temperature collect module start collecting work in the moment set, and keep low-frequency sampling; Microprocessor is by the attitude of attitude detection module-monitoring heat flow probe in seabed operation process and motion conditions, when judging that probe inserts and is still in marine bottom sediment, microprocessor start-up temperature acquisition module enters high frequency sample phase, records the temperature rise curve caused because of measuring unit head temperature sensor probe and marine bottom sediment friction; The heat of friction of setting terminates rear (being generally a few minutes) writing time, and microprocessor starting impulse trigger circuit provide constant heating current to heater strip, simultaneously by temperature collect module record temperature variation curve; All data and the temporal information of record are all kept in storage chip; After the heat time set terminates, microprocessor stops heating, and continuous high frequency sampling terminated to the high frequency sampling time set; After this measuring unit enters low-frequency sampling pattern, and heat flow probe is recycled to operation ship simultaneously.Measuring unit leaves after the water surface enters deck, special data reader carries out data read operation by connecting measuring unit shell, and the finite element numerical model (TC_FE) set up by FEPG software after the data of acquisition are transferred to PC is further carried out thermal conductivity numerical inversion and resolved.

Fig. 5 is temperature/attitude-time data that this device is surveyed at erect-position Ind2012HF12, the heat conductivity value that the data value that table 1 utilizes erect-position Ind2012HF12 to survey for this device resolves.

Table 1 Indian Ocean Ind2012HF12 erect-position in-situ heat conductance result of detection

In Fig. 6, data show the complete oceanic heat flow measuring process of Ind2012HF12 erect-position, and the data in figure are recorded by 3 different measuring units.The continuous curve of figure middle and lower part is the temperature consecutive variations curve that 3 measuring units record; The change of the loose expression measuring unit attitude at figure middle part.The temperature curve of slow decline shows, transfers to the process of seabed at heat flow probe from sea, and ocean temperature constantly declines; At distance seabed about 20m, heat flow probe can stop a period of time, then vertically inserts in marine bottom sediment in freely falling body mode; After static in insertion sediment, can see that attitude curve becomes straight line, show that attitude no longer changes; Now, due to temperature arrising caused by friction, temperature measuring unit can be recorded to temperature a pulse raised, and after this temperature declines and final identical with surrounding marine bottom sediment temperature gradually; Second increase pulses in temperature curve is that the heating of measuring unit startup heater strip causes, and the temperature be recorded in this stage raises and lower drop data will be used for resolving marine bottom sediment thermal conductivity; After thermal conductivity measurement terminates, heat flow probe is pulled out sediment once again, and regains on operation ship, now can know that heat flow probe rises in dynamic rocking by a small margin by attitude detection module.

Above-listed detailed description is illustrating for possible embodiments of the present invention, and this embodiment is also not used to limit the scope of the claims of the present invention, and the equivalence that all the present invention of disengaging do is implemented or changed, and all should be contained in the scope of the claims of this case.

Claims (2)

1. a calculation method for seabed in-situ heat conductance, is characterized in that: comprise the following steps:

(1) by the attitude of attitude monitoring module monitors probe in seabed and motion conditions, when judging that probe inserts and is still in marine bottom sediment after 7-10 minute, master control module controls thermal pulse control module excites thermal pulse to carry out electrical heating to the heater strip in measuring unit front-end probe;

(2) temperature collect module be connected with measuring unit by master control module controls carries out marine bottom sediment temperature data acquisition;

(3) main control module carries out from holding process to temperature data;

(4) be connected with the communication between optimum configurations with data reader by measuring unit from the data held and output to PC;

(5) by the finite element TC_FE numerical model that PC is set up, adopt mesh refinement search procedure to carry out parametric inversion, step is as follows:

1) marine bottom sediment is established to look thermal conductivity λ ₂₁with marine bottom sediment apparent volume thermal capacitance C ₂₁, wherein λ ₂₁for marine bottom sediment thermal conductivity λ and measuring unit front-end probe volumetric heat capacity C ₁ratio, i.e. λ/C ₁, C ₂₁for marine bottom sediment volumetric heat capacity C and measuring unit front-end probe volumetric heat capacity C ₁ratio, i.e. C/C ₁, to domain

$\left\{\begin{array}{c}{\mathrm{\&lambda;}}_{21}\&Element;[1.0\&times;{10}^{-7}{m}^2\&CenterDot;s^{-1},2.0\&times;{10}^{-6}{m}^2\&CenterDot;s^{-1}]\\ C_{21}\&Element;\left[\mathrm{0.1,4.0}\right]\end{array}\right.$ Middle two parameter all carries out m equal portions subdivision, obtains the individual grid node of initial (m+1) × (m+1) wherein i, j=1,2, Λ, m;

2) λ is got ₁₁=1.0 × 10 ^-4m ²s ^-1, utilize TC_FE model to calculate time, the T-t temperature data of measuring unit front-end probe top end, wherein T is temperature, and t is the time, is designated as wherein λ ₁₁for measuring unit front-end probe equivalent thermal conductivity λ ₁with its equivalent volume thermal capacitance C ₁ratio, namely because theoretical research shows, λ ₁₁change on inversion result impact very little, can ignore, therefore can according to the experience thermal conductivity of measuring unit front-end probe rapidoprint, volumetric specific heat capacity and thermal diffusivity variation range value, value λ ₁₁=1.0 × 10 ^-4m ²s ^-1;

3) finite element analogy acquisition is carried out by PC ((T is designated as with the T-t temperature data that probe is surveyed in marine bottom sediment _meas, t _n)) be normalized, obtain normalization std.T-t data:

$\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_n\right)=\frac{T_{\mathrm{mod}}^{i,j}\left(t_n\right)}{\mathrm{Max}\left\{T_{\mathrm{mod}}^{i,j}\left(t_n\right)\right\}},$

$\mathrm{std}.T_{\mathrm{meas}}\left(t_n\right)=\frac{[T_{\mathrm{meas}}\left(t_n\right)-T_{\mathrm{meas}}\left(0\right)]}{\mathrm{Max}\{T_{\mathrm{meas}}\left(t_n\right)-T_{\mathrm{meas}}\left(0\right)\}};$

4) least square method is utilized, right with std.T _meas(t _n) carry out linear fit and draw:

$\mathrm{std}.T_{\mathrm{meas}}\left(t_n\right)=K_1^{i,j}\&CenterDot;\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_n\right),$

Solve this fitting a straight line slope and coefficient R ^i,j, wherein Calculation of correlation factor expression formula is as follows

$R^{i,j}=\frac{n\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}(\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right)\&CenterDot;\mathrm{std}.T_{\mathrm{meas}}\left(t_k\right))-(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right))\&CenterDot;(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{std}.T_{\mathrm{meas}}\left(t_k\right))}{\sqrt{[n\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{(\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right))}^2-{(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{std}.T_{\mathrm{mod}}^{i,j}\left(t_k\right))}^2]\&CenterDot;[n\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{(\mathrm{std}.T_{\mathrm{meas}}\left(t_k\right))}^2-{(\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{std}.T_{\mathrm{meas}}\left(t_k\right))}^2]}};$

5) objective definition function is and solve the target function value at each net point place i, j=1,2, Λ, m;

6) net point that target function value is minimum is found out, $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})=\min \left\{F({\mathrm{\&lambda;}}_{21}^i,C_{21}^j)\right\},$ If $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})<\mathrm{\&epsiv;}(\mathrm{\&epsiv;}$ Require and the threshold value that sets for judging whether to meet to solve), then accept for the required marine bottom sediment solved looks thermal physical property parameter (λ ₂₁, C ₂₁), otherwise, will be with centered by neighborhood be domain, by mesh refinement, turn back to step 2), until meet $F({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0})<\mathrm{\&epsiv;}$ For this reason, thus resolve and obtain marine bottom sediment and look thermal physical property parameter $({\mathrm{\&lambda;}}_{21},C_{21})=({\mathrm{\&lambda;}}_{21}^{i0},C_{21}^{j0});$

7) again least square method is utilized, right with T _meas(t _n) carry out linear fit:

marine bottom sediment environment temperature T is recorded according to temperature collect module ₀, solve its fitting a straight line slope with wherein

$K_2^{i,j}=\frac{H_{0\_\mathrm{meas}}}{H_{0\_\mathrm{mod}}}=\frac{A_{0\_\mathrm{meas}}/C_1}{A_{0\_\mathrm{mod}}/C_1},$

Measuring unit front-end probe volume heat generation rate A is obtained according to the PULSE HEATING Current calculation that step (1) records _{0_meas}, the apparent volume heat generation rate H of probe is drawn according to TC_FE model _{0_mod}=A _{0_mod}/ C ₁, the volumetric heat capacity obtaining popping one's head in can be solved thus

$C_1=\frac{A_{0\_\mathrm{meas}}}{K_2^{i,j}\&CenterDot;[A_{0\_\mathrm{mod}}/C_1]}=\frac{A_{0\_\mathrm{meas}}}{K_2^{i,j}\&CenterDot;H_{0\_\mathrm{mod}}},$

Again according to λ=λ ₂₁c ₁marine bottom sediment thermal conductivity can be solved.

2. one kind implements the claims the sniffer of the seabed in-situ heat conductance of 1, comprise front-end probe, probe internally provided temperature-sensing element and heater strip, it is characterized in that: also comprise main control module, temperature collect module, attitude detection module and thermal pulse control module, main control module is by microprocessor, usb circuit, real-time clock, storer and DC constant voltage electric power generating composition, usb circuit, real-time clock, storer, DC constant voltage power supply are corresponding with microprocessor to be respectively electrically connected, and usb circuit is connected with PC communication by USB; Temperature collect module is made up of constant-current source circuit, temperature signal regulation circuit and temperature detecting resistance bridge, constant-current source circuit, temperature signal regulation circuit, thermistor are corresponding with temperature detecting resistance bridge to be respectively electrically connected, and temperature signal regulation circuit is corresponding with microprocessor to be electrically connected; Attitude detection module is made up of attitude signal modulate circuit and attitude sensor, and attitude sensor is electrically connected with attitude signal modulate circuit, and attitude signal modulate circuit is corresponding with microprocessor to be electrically connected; Thermal pulse control module is made up of DC constant flowing power and pulsed triggering circuit, and DC constant flowing power, heater strip are electrically connected with pulsed triggering circuit respectively, and DC constant flowing power is corresponding with microprocessor to be electrically connected.