CN104048993A - Portable in-situ shallow geotemperature and heat conductivity coefficient measurement device and testing method - Google Patents

Abstract

The invention relates to a portable in-situ shallow geotemperature and heat conductivity coefficient measurement device and a testing method. A tablet personal computer is connected with a storage battery by a PLC (Programmable Logic Controller), the storage battery is connected with a solid-state relay and a temperature transmitter respectively, and the PLC is connected with a temperature sensor through the temperature transmitter, and connected with a heating wire through the solid-state relay. The problem of not simultaneously testing the shallow geotemperature in situ and the heat conductivity coefficient of a soil layer for a long time can be solved; both the temperature and the heat conductivity coefficient can be tested under the control of a parallel circuit; a data acquisition and management system is arranged, the measurement precision is high, the operation is simple, and the operation process is visible; an injection system is arranged, and the device is convenient to carry, capable of conducting measurement everywhere, free of the limit of drilling equipment and vehicles, simple and convenient to work in the wild, simple in technology, low in cost, and high in working efficiency.

Description

Portable in-situ shallow earth and heat conductivity measuring device and method of testing

Technical field

The present invention relates to a kind of engineering geology parameters measurement mechanism and method, especially obtain original position shallow earth and heat conductivity measuring device and method of testing

Background technology

Along with non-renewable energy resources are day by day in short supply, the inexorable trend that the renewable shallow layer geothermal energy resource that develops cleanliness without any pollution has been social development.Current domestic shallow layer geothermal energy exploration engineering field does not have professional Portable in-situ shallow earth and Determination of conductive coefficients system.Existing Portable temperature or coefficient of heat conductivity probe test equipment:

" material science " 2006.39 (6) p65-70 disclose " utilizing sonde method to measure the coefficient of heat conductivity of soil " such as Meng Fanfeng, and the method and be confined to earth's surface and use cannot be used for underground in site measurement.

CN202770794U discloses " a kind of experiment automatically controlled heating measurement mechanism of sandy soil medium thermal conduction characteristic detection system " and has comprised heating rod and temperature sensor, main frame comprises processor and measurement and control unit, switch arrays comprise at least four electrode switch, each electrode switch comprises electrode, switch and switch measure and control device, processor sends the first steering order to automatically controlled heating measurement mechanism, controlling heating rod heats sandy soil medium, and processor sends the second steering order to switch arrays, switch measure and control device changes the state of connected switch to respond the electric parameter that changes the electrode being connected with this switch according to the second steering order, the temperature of temperature sensor measurement sandy soil medium, measurement and control unit is measured the electric parameter of the electrode in power supply state, switch measure and control device is measured the electric parameter of the electrode in measuring state.

CN202770796U disclose " a kind of thermal conductivity measurement system " for the temperature signal on collecting test sample machine show, the Test Host of analyzing and processing and the work of control test sample machine, for the host computer of calculation of thermal conductivity, real-time monitored and many multidata processing and printout; Described Test Host is connected with test sample machine, host computer respectively by connecting line.

CN101320007 discloses a kind of " material thermal conductivity measurement apparatus by probe method ", and it comprises probe, microprocessor system and stabilized voltage supply, probe comprises electrical heating wire, probe tube and thermopair, thermopair and heater strip are placed in the inside of probe tube, insert the probe of measured material measurement material temperature electric potential signal is sent in microprocessor system, process, convert and show; Stabilized voltage supply provides constant voltage to make heating power constant to electrical heating wire, and its voltage range value is by microprocessor system control.Only heat conducting coefficient measuring and do not consider to measure temperature, and be confined to earth's surface and use, cannot be used for underground in site measurement.

CN102141528A discloses " a kind of original position soil layer heat conduction coefficient measuring " and has comprised that one can be pressed into by mechanical perforation device the conical probe of soil layer, described probe is made up of conical conehead, cylinder barrel and top connection, wherein on conical conehead, be provided with primary probe and at least two little probes of correspondence by synchronous telescopic device control, in primary probe, be provided with heating arrangement, it is positioned at the center of conehead, and the relative primary probe of each little probe is uniformly-spaced distributed on surrounding; In little probe, be provided with highly sensitive temperature sensor, the signal conductor of little probe and primary probe is connected with control instrument through cylinder barrel, top connection.Need large-scale vehicle-mounted mechanical perforation device to be pressed into soil layer, probe process of press in has larger perturbation to stratum.And only heat conducting coefficient measuring, can not measure ground temperature.Single measurement temperature or coefficient of heat conductivity cannot calculate underground heat flow field exactly, can not measure exactly underground heat abnormal occurrence.

Sladek C, Coolbaugh M F, Zehner R E.Development of2-meter soil temperature probes and results of temperature survey conducted at Desert Peak, Nevada, USA[J] .Geothermal Resources Council Transactions, 2007, that 31:363-368. discloses is a kind of " 2 meters dark development of soil moisture detector and the investigation of the temperature of result ", this equipment depends on mobile generator, utilize electric hammer or electric drill that drilling rod in 2.2 meters is pierced to underground 2 meters of depths, then temperature probe is put into hollow drill pipe and after inner 1 hour, recorded measurement temperature, but a whole set of test macro is portable not, surveying work is confined to the place that vehicle can arrive, the too mechanization of measuring method and collecting method, descend immeasurably coefficient of heat conductivity, do not belong to in-situ technique.

Summary of the invention:

Object of the present invention is just for above-mentioned the deficiencies in the prior art, and a kind of Portable in-situ shallow earth and heat conductivity measuring device are provided;

Another object of the present invention is to provide the method for testing of a kind of Portable in-situ shallow earth and heat conductivity measuring device.

The object of the invention is to be achieved through the following technical solutions:

Portable in-situ shallow earth and heat conductivity measuring device, to be connected with accumulator 3 through PLC2 by the panel computer 1 of initialize data acquisition management system, accumulator 3 connects respectively solid-state relay 5 and temperature transmitter 4, PLC2 Yi road is connected with the temperature sensor 6 being placed in probe case 8 with wire through temperature transmitter 4, another road of PLC2 is connected with the heater strip 7 being placed in probe case 8 with wire through solid-state relay 5, and the front end of probe case 8 is provided with probe 9 and forms.

In probe case 8, conduction oil is housed.

Probe case 8 and probe 9 are placed in the cavity of auger drill head, and drill bit cavity front end is equipped with magnetic cone point 11, and its tail end slightly larger in diameter is in probe case 8 leading portion diameters.

Probe case 8 and drill bit cavity are variable-diameter structure, drill bit cavity thin diameter section is ﹥ 5mm, probe case 8 thin diameter sections are ﹤ 5mm, drill bit cavity top wide section diameter is 10mm, probe case 8 top wide section diameters are ﹤ 10mm, between the wide section of drill bit cavity and probe case 8 and thin diameter section, be equipped with inclined-plane half the circumference of the sleeve where it joins the shoulder, 20 ° of inclined-plane and center line angles.

Probe case 8 is slidably matched in the cavity of auger drill head 10.

The data acquisition management system of Portable in-situ shallow earth and test device of thermal conductivity coefficient, comprises the following steps:

A, beginning, input measurement point position information is also preserved;

B, measurement ground temperature t;

C, temperature stabilization, record data are also preserved;

D, heat conducting coefficient measuring;

E, heating, record heat time τ, and record τ moment temperature, calculation of thermal conductivity λ;

F, coefficient of heat conductivity λ are stable, and record data are also preserved;

G, by initial temperature t ₀bring underground heat transfer model into coefficient of heat conductivity λ computation and measurement point underground heat flow field, determines according to heat conduction model whether measurement point has thermal anomaly phenomenon;

In formula, λ is coefficient of heat conductivity, unit: W/ (mK); T is the temperature increasing progressively with the degree of depth, K; Z is the degree of depth, and the negative sign in formula represents the direction of hot-fluid and the opposite direction that temperature increases progressively;

H, there is thermal anomaly, have thermal source; No, without thermal source.

The method of testing of Portable in-situ shallow earth and test device of thermal conductivity coefficient, comprises the following steps:

A, preliminary work: first magnetic cone point 11 is proceeded in the hole of chisel edge on earth's surface, connect drill bit, drilling rod and unit head, rig starts to creep into, stop boring when creeping into after projected depth upwards promotes drilling rod 2-3cm, and fixing drilling rod, unloads unit head;

B, pack wire socket by connecting the wire of heating wire 7 into the wire that is connected temperature sensor 6, then the wire socket that wire is housed is packed in drilling rod and drill bit cavity in the lump;

C, be connected with temperature transmitter 4 connecting the wire of temperature sensor 6, the wire of connection heating wire 7 be connected with solid-state relay 5 simultaneously;

D, push away the probe 9 10-12cm that buries downwards by wire socket, the probe 9 that Sensor section is housed is inserted to the soil layer of drill bit below without disturbance;

E, temperature survey start, start to gather Geothermal Information by panel computer 1 by programmable memory 2 temperature sensors 6, and feed back to panel computer 1, and showing ground temperature temporal evolution curve, the temperature after tending towards stability is the initial temperature t of measurement point underground temperature field ₀and preserve;

F, data acquisition management system are opened thermal conductivity measurement circuit, and heater strip and temperature sensor are started working simultaneously, start timing from τ=0, start to record temperature acquisition number of times from i=0, record τ _ithe temperature t that moment gathers for the i time _i, pass through formula:

${\mathrm{\λ}}_i=\frac{q}{4\mathrm{\π}}\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_i\mathrm{\Σ}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}$

Calculate τ _ithe coefficient of heat conductivity λ in moment _i, and real-time Apparent thermal conductivity λ temporal evolution curve, the coefficient of heat conductivity showing after curve is stable is measurement point formation thermal conductivity.

G, by initial temperature t ₀determine with coefficient of heat conductivity λ whether measurement point has thermal anomaly phenomenon, if there is thermal anomaly phenomenon, judges that measurement point is underground and there is thermal source, on the contrary the nothing of being judged to be.

Beneficial effect: the invention solves and can not carry out for a long time the problem that in-situ test shallow earth and soil layer coefficient of heat conductivity are tested simultaneously; Adopt parallel circuit control, can survey again coefficient of heat conductivity by thermometric, with data acquisition management system, measuring accuracy is high, simple to operate, and operating process is visual; Carry injection system, be convenient for carrying, measure everywhere, be not subject to boring apparatus and vehicle restriction, field work is easy, and technique is simple, with low cost, and work efficiency is high;

Brief description of the drawings:

Accompanying drawing 1 is Portable in-situ shallow earth and heat conductivity measuring device structural drawing

Accompanying drawing 2 is A-A ' cut-open views in Fig. 1

Accompanying drawing 3 is drill bit 10 structural drawing in Fig. 1

Accompanying drawing 4 is drill bit 10 cut-open views in Fig. 1

Accompanying drawing 5 is Portable in-situ shallow earth and Determination of conductive coefficients process flow diagram

1 panel computer, 2 programmable storages, 3 accumulators, 4 temperature transmitters, 5 transistor switches, 6 temperature sensors, 7 heater strips, 8 probe case, 9 probes, 10 drill bits, 11 magnetic cone points.

Embodiment:

Be described in further detail below in conjunction with drawings and Examples:

Portable in-situ shallow earth and Determination of conductive coefficients instrument, to be connected with accumulator 3 through PLC2 by the panel computer 1 of initialize data acquisition management system, accumulator 3 connects respectively solid-state relay 5 and temperature transmitter 4, PLC2 Yi road is connected with the temperature sensor 6 being placed in probe case 8 with wire through temperature transmitter 4, another road of PLC2 is connected with the heater strip 7 being placed in probe case 8 with wire through solid-state relay 5, and the front end of probe case 8 is provided with probe 9 and forms.

In probe case 8, conduction oil is housed.

Probe case 8 and probe 9 are placed in the cavity of auger drill head, and drill bit cavity front end is equipped with magnetic cone point 11, and its tail end slightly larger in diameter is in probe case 8 leading portion diameters.

Probe case 8 and drill bit cavity are variable-diameter structure, drill bit cavity thin diameter section is ﹥ 5mm, probe case 8 thin diameter sections are ﹤ 5mm, drill bit cavity top wide section diameter is 10mm, probe case 8 top wide section diameters are ﹤ 10mm, between the wide section of drill bit cavity and probe case 8 and thin diameter section, be equipped with inclined-plane half the circumference of the sleeve where it joins the shoulder, 20 ° of inclined-plane and center line angles.

Probe case 8 is slidably matched in the cavity of auger drill head 10.

The data acquisition management system of Portable in-situ shallow earth and test device of thermal conductivity coefficient, comprises the following steps:

A, beginning, input measurement point position information is also preserved;

B, measurement ground temperature t;

C, temperature stabilization, record data are also preserved;

D, heat conducting coefficient measuring;

E, heating, record heat time τ, and record τ moment temperature, calculation of thermal conductivity λ;

F, coefficient of heat conductivity λ are stable, and record data are also preserved;

G, by initial temperature t ₀bring underground heat transfer model into coefficient of heat conductivity λ underground heat flow field, computation and measurement point position, determines according to heat conduction model whether measurement point has thermal anomaly phenomenon;

In formula, the coefficient of heat conductivity that λ is rock, unit: W/ (mK); T is the temperature increasing progressively with the degree of depth, K; Z is the degree of depth, and the negative sign in formula represents the direction of hot-fluid and the opposite direction that temperature increases progressively, and hot-fluid q is based on two fundamental measurements: the one, and temperature survey on the spot, the 2nd, temperature measuring section geologic body thermal conductivity measurement;

H, there is thermal anomaly, have thermal source; No, without thermal source.

The method of testing of Portable in-situ shallow earth and test device of thermal conductivity coefficient, comprises the following steps:

A, preliminary work: first magnetic cone point 11 is proceeded in the hole of chisel edge on earth's surface, connect drill bit, drilling rod and unit head, rig starts to creep into, stop boring when creeping into after projected depth upwards promotes drilling rod 2-3cm, and fixing drilling rod, unloads unit head;

B, pack wire socket by connecting the wire of heating wire 7 into the wire that is connected temperature sensor 6, then the wire socket that wire is housed is packed in drilling rod and drill bit cavity in the lump;

C, be connected with temperature transmitter 4 connecting the wire of temperature sensor 6, the wire of connection heating wire 7 be connected with solid-state relay 5 simultaneously;

D, push away the probe 9 10-12cm that buries downwards by wire socket, the probe 9 that Sensor section is housed is inserted to the soil layer of drill bit below without disturbance;

E, temperature survey start, start to gather Geothermal Information by panel computer 1 by programmable memory 2 temperature sensors 6, and feed back to panel computer 1, and showing ground temperature temporal evolution curve, the temperature after tending towards stability is the initial temperature t of measurement point underground temperature field ₀and preserve;

F, data acquisition management system are opened thermal conductivity measurement circuit, and heater strip and temperature sensor are started working simultaneously, start timing from τ=0, start to record temperature acquisition number of times from i=0, record τ _ithe temperature t that moment gathers for the i time _i, pass through formula:

${\mathrm{\λ}}_i=\frac{q}{4\mathrm{\π}}\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_i\mathrm{\Σ}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}$

Calculate τ _ithe coefficient of heat conductivity λ in moment _i, and real-time Apparent thermal conductivity λ temporal evolution curve, the coefficient of heat conductivity showing after curve is stable is measurement point formation thermal conductivity.

G, by initial temperature t ₀determine with coefficient of heat conductivity λ whether measurement point has thermal anomaly phenomenon, if there is thermal anomaly phenomenon, judges that measurement point is underground and there is thermal source, on the contrary the nothing of being judged to be.

In infinitely-great isothermal medium, insert that infinite in length is long, the infinitesimal line heat source of diameter, as the hot-fluid with firm power heats hot line source, hot line source and ambient substance thereof will produce temperature rise, just can obtain the coefficient of heat conductivity of medium according to the temperature rise of hot line source.In theory, sonde method is the unstable state heat conduction based in infinite medium, and the simplified condition in diabatic process is as follows:

(1) underground is approximately the uniform heat transfer medium of infinitely-great initial temperature;

(2) the hot physical property of underground is uniformly, and does not change with the variation of the soil moisture;

(3) ignore the geometric scale of boring and boring be approximately to the line heat source of endless on axial line;

According to above-mentioned hypothesis, the heat transfer of depth direction (comprising earth's surface) is not considered, and then this heat transfer problem is reduced to the one dimensional heat transfer problem under cylindrical-coordinate system.Boring heat transfer is around actually one dimension axisymmetric problem, and governing equation, starting condition and boundary condition are respectively:

$\frac{\∂T}{\∂\mathrm{\τ}}=\frac{a}{r}\frac{\∂}{\∂r}\left(r\frac{\∂T}{\∂r}\right)$

T(r,0)＝0

$-\mathrm{\λ}\frac{\∂T}{\∂r}(0,\mathrm{\τ})\·2\mathrm{\πr}{|}_{r=0}=q$

The too temperature field distribution function in τ moment is:

$\mathrm{\θ}=t-t_0=\frac{-q}{4\mathrm{\π\λ}}{E}_i(-\frac{r^2}{4\mathrm{a\τ}})---\left(1\right)$

In formula, θ is excess enthalpy temperature; τ is the heat time; Q is heating power; λ is medium heat conduction coefficient; A is thermal diffusion coefficient (Thermal Diffusivity); R is the distance of certain point to line heat source; T is the temperature in τ moment; t ₀for initial temperature; Ei is exponential integral function, and its expression formula is:

$E_i(-\mathrm{\μ})=C+1n\left(\mathrm{\μ}\right)-\mathrm{\μ}+\frac{{\mathrm{\μ}}^2}{2\·2!}-\frac{{\mathrm{\μ}}^3}{3\·3!}+...+\frac{{(-\mathrm{\μ})}^i}{i\·i!}+...$

Wherein μ=r ²/ 4a τ.

When r less, when τ is larger, when the value of μ is very little, E _iapproximate front two expressions of getting series expansion of value of (μ), that is:

E _i(-μ)＝C+ln(μ)

Substitution (1) formula has:

$\mathrm{\θ}=t-t_0=\frac{-q}{4\mathrm{\π\λ}}[-C-1n\left(\frac{r^2}{4\mathrm{a\τ}}\right)]---\left(2\right)$

In formula, c=0.57726, is called Euler's constant.

As τ=τ ₁time, t=t ₁; τ=τ ₂time, t=t ₂, the temperature at r place can be expressed as:

${\mathrm{\θ}}_2-{\mathrm{\θ}}_1=t_2-t_1=\frac{q}{4\mathrm{\π\λ}}1n\left(\frac{{\mathrm{\τ}}_2}{{\mathrm{\τ}}_1}\right)$

Therefore have:

$\mathrm{\λ}=\frac{q}{4\mathrm{\π}(t_2-t_1)}1n\left(\frac{{\mathrm{\τ}}_2}{{\mathrm{\τ}}_1}\right)---\left(3\right)$

Through type (3) distortion has:

$\frac{4\mathrm{\π\λ}}{q}=\frac{1n{\mathrm{\τ}}_2-1n{\mathrm{\τ}}_1}{t_2-t_1}---\left(4\right)$

Can find out that ln τ and t are linear relationship, establish:

lnτ＝α ₀+α ₁t (5)

Application " principle of least square method ", by measured value ln τ _iwith utilize formula (5) calculated value (ln τ _j=a ₀+ a ₁t _i) quadratic sum ∑ (the ln τ of deviation _i-ln τ _j) ²minimum is " optimization criterion "; Obtain:

$a_0=\frac{\left(\mathrm{\Σ}1n{\mathrm{\τ}}_i\right)-a_1\left(\mathrm{\Σ}{t}_i\right)}{n}---\left(6\right)$

$a_1=\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_i\mathrm{\Σ}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}---\left(7\right)$

Had by (5) and (7):

$\frac{{4\mathrm{\π\λ}}_i}{q}=\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_{i}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}---\left(8\right)$

That is:

${\mathrm{\λ}}_i=\frac{q}{4\mathrm{\π}}\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_i\mathrm{\Σ}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}$

Test as example taking somewhere, Changchun:

1, assembling measurement mechanism, packs magnetic cone point 11 in bit point of the drill aperture into, connects drill bit, drilling rod and gasoline engine, and bit point of the drill is placed in to the position that pierces that earth's surface chooses, buttress gasoline engine keep drilling rod for vertically to; Start gasoline engine, make bit drills underground layer, pierce after the degree of depth reaches 1.95 meters and stop creeping into, unload gasoline engine; On drilling rod, carry 2～3 centimetres, drill bit 10 and soil layer are departed from, connect measuring sonde, and by wire socket, probe and wire are put into drilling rod hole, wait to put into 1.95 meters of degree of depth, after probe case 8 tips contact with magnetic cone point 11, to the downward application of force of wire socket, make measuring probe 9 magnetic cone point 11 be ejected to aperture downwards, probe inserts the soil layer of drill bit below without disturbance smoothly by bit point of the drill aperture, after 10 centimetres of insertion depths, stop, to the wire socket application of force, completing measuring probe injection, carry out 2.00 meters of deep hypothermias and coefficient of heat conductivity in site measurement;

2, connect respectively temperature sensor 6 and heater strip 7 by Fig. 1 panel computer 1 by wire, open panel computer, the data acquisition management system in operation panel computer, the information such as coordinate, formation information, Measuring Time and the measurement environment of input measurement point position;

3, pass through data acquisition management system, click " temperature survey " button, open temperature measuring circuit, temperature transmitter and temperature sensor are started working, the underground temperature data recording of data acquisition management system Real-time Collection dynamically displays temperature change curve, after approximately 5 minutes, temperature curve tends to be steady, sample ten times, and displays temperature t successively ₀for: 25.58,19.63,18.14,17.76,17.49,17.36,17.29,17.30,17.28,17.29; Unit: W/ (mK).17.29W/ (mK) is the initial temperature in temperature field, the underground 2.00 meters of depths of measurement point, clicks " preservation " button, preserves measurement data;

4, by data acquisition management system, click " thermal conductivity measurement " button, open thermal conductivity measurement circuit, heating system and temp measuring system are worked simultaneously, start timing from τ=0, start to record temperature acquisition number of times from i=0, record τ _ithe temperature t that moment gathers for the i time _i, pass through formula:

${\mathrm{\λ}}_i=\frac{q}{4\mathrm{\π}}\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_i\mathrm{\Σ}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}$

Calculate τ _ithe coefficient of heat conductivity λ in moment _i, and real-time Apparent thermal conductivity λ temporal evolution curve, the coefficient of heat conductivity showing after curve is stable is measurement point geologic body coefficient of heat conductivity.

The real-time calculation of thermal conductivity λ of data acquisition management system, and dynamic Apparent thermal conductivity λ temporal evolution curve, after approximately 1 minute, curve is stable, sample ten times, Apparent thermal conductivity λ successively ₀for: 2.358,1.790,1.620,1.571,1.553,1.541,1.539,1.536,1.537,1.535; Unit: W/ (mK).1.535W/ (mK) is measurement point formation thermal conductivity, clicks " preservation " button, preserves thermal conductivity measurement data;

6, by data acquisition management system, click " terrestrial heat flow calculating " button, judgment result displays does not have thermal anomaly, thereby judges that this place does not exist the underground thermal source of hiding.

7, this point measurement finishes, and disconnects wire, extracts drilling rod, and point " exits " button and exits data acquisition management system;

8, repeat above-mentioned 1-7 step, change fathoms, and restarts new surveying work.

Claims (7)

1. a Portable in-situ shallow earth and test device of thermal conductivity coefficient, it is characterized in that, to be connected with accumulator 3 through PLC2 by the panel computer 1 of initialize data acquisition management system, accumulator 3 connects respectively solid-state relay 5 and temperature transmitter 4, PLC2 Yi road is connected with the temperature sensor 6 being placed in probe case 8 with wire through temperature transmitter 4, another road of PLC2 is connected with the heater strip 7 being placed in probe case 8 with wire through solid-state relay 5, and the front end of probe case 8 is provided with probe 9 and forms.

2. according to a kind of Portable in-situ shallow earth claimed in claim 1 and test device of thermal conductivity coefficient, it is characterized in that, in probe case 8, conduction oil is housed.

3. according to a kind of Portable in-situ shallow earth claimed in claim 1 and test device of thermal conductivity coefficient, it is characterized in that, probe case 8 and probe 9 are placed in the cavity of auger drill head, and drill bit cavity front end is equipped with magnetic cone point 11, and its tail end slightly larger in diameter is in probe case 8 leading portion diameters.

4. according to a kind of Portable in-situ shallow earth claimed in claim 1 and test device of thermal conductivity coefficient, it is characterized in that, probe case 8 and drill bit cavity are variable-diameter structure, drill bit cavity thin diameter section is ﹥ 5mm, probe case 8 thin diameter sections are ﹤ 5mm, and drill bit cavity top wide section diameter is 10mm, and probe case 8 top wide section diameters are ﹤ 10mm, between the wide section of drill bit cavity and probe case 8 and thin diameter section, be equipped with inclined-plane half the circumference of the sleeve where it joins the shoulder, 20 ° of inclined-plane and center line angles.

5. according to a kind of Portable in-situ shallow earth claimed in claim 1 and test device of thermal conductivity coefficient, it is characterized in that, probe case 8 is slidably matched in the cavity of auger drill head 10.

6. according to a kind of Portable in-situ shallow earth claimed in claim 1 and test device of thermal conductivity coefficient, it is characterized in that, described data acquisition management system, comprises the following steps:

A, beginning, input measurement point position information is also preserved;

B, measurement ground temperature t;

C, temperature stabilization, record data are also preserved;

D, heat conducting coefficient measuring;

E, heating, record heat time τ, and record τ moment temperature, calculation of thermal conductivity λ;

F, coefficient of heat conductivity λ are stable, and record data are also preserved;

G, by initial temperature t ₀bring underground heat transfer model into coefficient of heat conductivity λ computation and measurement point underground heat flow field, determines whether measurement point has thermal anomaly phenomenon;

In formula, the coefficient of heat conductivity that λ is rock, unit: W/mK; T is the temperature increasing progressively with the degree of depth, K; Z is the degree of depth, and the negative sign in formula represents the direction of hot-fluid and the opposite direction that temperature increases progressively;

H, there is thermal anomaly, have thermal source; No, without thermal source.

7. a method of testing for Portable in-situ shallow earth and test device of thermal conductivity coefficient, is characterized in that, comprises the following steps:

A, preliminary work: first magnetic cone point 11 is proceeded in the hole of chisel edge on earth's surface, connect drill bit, drilling rod and unit head, rig starts to creep into, stop boring when creeping into projected depth, unloads unit head, upwards promotes drilling rod 2-3cm, and fixing drilling rod;

B, pack wire socket by connecting the wire of heating wire 7 into the wire that is connected temperature sensor 6, then the wire socket that wire is housed is packed in drilling rod and drill bit cavity in the lump;

C, be connected with temperature transmitter 4 connecting the wire of temperature sensor 6, the wire of connection heating wire 7 be connected with solid-state relay 5 simultaneously;

D, push away the probe 9 10-12cm that buries downwards by wire socket, the probe 9 that Sensor section is housed is inserted to the soil layer of drill bit below without disturbance;

E, temperature survey start, start to gather Geothermal Information by panel computer 1 by programmable memory 2 temperature sensors 6, and feed back to panel computer 1, and showing ground temperature temporal evolution curve, the temperature after tending towards stability is the initial temperature t of measurement point underground temperature field ₀and preserve;

F, data acquisition management system are opened thermal conductivity measurement circuit, and heater strip and temperature sensor are started working simultaneously, start timing from τ=0, start to record temperature acquisition number of times from i=0, record τ _ithe temperature t that moment gathers for the i time _i, pass through formula:

${\mathrm{\λ}}_i=\frac{q}{4\mathrm{\π}}\frac{\mathrm{n\Σ}{t}_{i}1n{\mathrm{\τ}}_i-\mathrm{\Σ}{t}_i\mathrm{\Σ}1n{\mathrm{\τ}}_i}{\mathrm{n\Σ}{t}_i^2-{\left(\mathrm{\Σ}{t}_i\right)}^2}$

Calculate τ _ithe coefficient of heat conductivity λ in moment _i, and real-time Apparent thermal conductivity λ temporal evolution curve, the coefficient of heat conductivity showing after curve is stable is measurement point formation thermal conductivity.

G, by initial temperature t ₀determine with coefficient of heat conductivity λ whether measurement point has thermal anomaly phenomenon, if there is thermal anomaly phenomenon, judges that measurement point is underground and there is latent type thermal source, on the contrary the nothing of being judged to be.