CN111139179A

CN111139179A - Portable isothermal amplification rapid detector capable of independently controlling temperature

Info

Publication number: CN111139179A
Application number: CN201911366438.0A
Authority: CN
Inventors: 陈皓; 叶子弘; 樊伟东; 骆志成; 郦宏; 管峰
Original assignee: China Jiliang University
Current assignee: China Jiliang University
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-05-12
Anticipated expiration: 2039-12-26
Also published as: CN111139179B

Abstract

The invention discloses a portable constant-temperature fluorescence detector capable of independently controlling temperature, which belongs to the field of biological detection and comprises a shell, wherein a plurality of light source modules, a plurality of heating modules, a plurality of radiating modules, a plurality of detection modules, a heat cover module, an interface module, a main control board and a secondary control board are arranged in the shell, the heat cover module is arranged on the shell, the radiating module is arranged below the heating modules, one side of each heating module is connected with the corresponding light source module, and the other side of each heating module is connected with the corresponding detection module. The invention adopts the design of a modularized device, and a manufacturer can customize detection instruments with different hole site quantities according to the requirements of customers. Meanwhile, if the detection instrument has redundant detection positions, the same user can simultaneously carry out constant temperature detection experiments at different temperatures; different users can detect the experiment under the condition that does not influence other people and be using, and both do not influence each other, have improved experimental efficiency and instrument rate of utilization.

Description

Portable isothermal amplification rapid detector capable of independently controlling temperature

Technical Field

The invention relates to the field of biological detection instruments, in particular to a portable isothermal amplification rapid detector capable of independently controlling temperature.

Background

Polymerase Chain Reaction (PCR) is a process of in vitro copying daughter strand DNA complementary to a parent strand DNA by using the parent strand DNA as a template and a specific primer as an extension origin under the catalysis of DNA polymerase through the steps of denaturation, annealing, extension and the like. The characteristics of high specificity and high sensitivity make the molecular probe be widely applied to the field of molecular biology. However, the conventional PCR technique requires expensive instruments and is not portable because the temperature-changing process requires a large-sized thermal cycling device.

In recent years, with the rise of nucleic acid isothermal amplification technology, various corresponding isothermal amplification detection instruments are developed in succession, and due to the characteristics of constant temperature and portability, the complexity and experimental operation procedures of the instruments are simplified, and meanwhile, the change of fluorescence intensity can be monitored in real time, so that the occurrence of false negative conditions is effectively avoided.

At present, the temperature of the continuous holes of most portable isothermal amplification instruments after heating is in Poisson distribution, the uniformity is poor, the maximum temperature difference between the holes is about 0.5 ℃, and the temperature can influence the efficiency of fluorescent dye or fluorescent probe, so that the fluorescence intensity is different. Although the PCR instrument with the isothermal amplification function is available abroad, the purchase cost is higher than that of the common PCR instrument, the structure is more complicated, and the PCR instrument is not suitable for most laboratory researchers or professional detection personnel.

The Chinese patent application No. CN201910698218.1 discloses an automatic controllable multi-temperature real-time microorganism detector, but in the scheme, the positions of a light source and a detector in a photoelectric detection column determine that a gap exists between a detection hole and a test tube, and part of excitation light emitted by the light source without an addition polymerization lens influences the detection result of the detector in the gap.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a portable isothermal amplification rapid detector capable of independently controlling temperature.

The technical scheme of the invention is as follows: the utility model provides a portable constant temperature fluorescence detector of independent temperature control, includes the shell, be equipped with a plurality of light source module, a plurality of heating module, a plurality of heat dissipation module, a plurality of detection module, hot cover module, interface module, main control board and vice control board in the shell, be equipped with hot cover module on the shell, the below of heating module is equipped with heat dissipation module, one side of heating module is connected with light source module, and the opposite side is connected with detection module, hot cover module, light source module, heating module, heat dissipation module and main control board are connected with vice control board respectively, the main control board is connected with detection module and interface module respectively.

The heating module comprises a base, a heat preservation layer, a fixing plate, a heating sheet, screws and a copper column, wherein the copper column is fixed on the bottom surface inside the shell, the fixing plate is fixed on the copper column, the heating sheet is fixed at the center of the fixing plate, the base is arranged above the heating sheet, the base is connected with the fixing plate through the screws, a heating test tube is placed in the base, the heat preservation layer is arranged outside the base, and the heating sheet is electrically connected with the auxiliary control board.

The base includes ring columniform basement and square sleeve, the sleeve is established in the basement, telescopic inner wall and heating test tube outer wall laminate mutually, it all has circular opening to correspond light path passageway and fiber channel department around the sleeve, the basement size of base is the same with the heating plate size, the fixed plate is the Z template.

The heat dissipation module comprises a heat dissipation sheet and a fan, two ends of the heat dissipation sheet are fixed on the copper columns, the fan is arranged below the heat dissipation sheet, the fan is connected with the auxiliary control plate, and the heat dissipation sheet is fixed below the heating sheet.

The light path module comprises a light source, an excitation light filter, a lens and a light path channel, wherein the excitation light source is arranged at one end inside the light path channel, the lens is arranged in the light path channel, the light path channel is divided into two parts, one part is a cylindrical light channel which accords with the size of the light source and is divided by the lens, the other part is a truncated cone-shaped channel with the gradually reduced aperture, the bottom of the light path channel is supported by a light source module support, the light source is arranged on an auxiliary control board, and the auxiliary control board is fixed on the shell through an auxiliary control board support.

The hot lid links to each other with the shell through hot lid pivot, the below of hot lid one end is equipped with a plurality of laminating portion, and the lower part of every laminating portion all is equipped with heating film and copper sheet, heating film is connected with vice accuse board, be equipped with a plurality of and laminating portion complex recess on the shell, separate each other through the parting bead between each recess, the bottom of recess is equipped with the heat insulating board, recess and heat insulating board link to each other with the upper end of heating module.

The top of hot lid is equipped with the draw-in groove, the shell top is equipped with hot lid kayser, hot lid kayser and draw-in groove joint cooperation, be equipped with joint strip around the laminating portion.

The detection module comprises an optical fiber channel, an optical fiber fixer, a loose screw, an optical fiber support, an optical fiber, a cassette, an emission optical filter and a detector, wherein the optical fiber is arranged in the optical fiber channel, one end of the optical fiber is connected with the opening of the side wall of the base, the other end of the optical fiber is connected with the cassette, two ends of the optical fiber channel are fixed through the optical fiber fixer, the optical fiber in the optical fiber channel is fixed in position through the loose screw on the optical fiber fixer, the cassette is installed on the main control board, and the emission optical filter and the photoelectric detector are installed in.

The interface module is fixed on the side face of the shell and comprises a USB-A interface, a USB-B interface and a power interface, the USB-A interface and the USB-B interface are connected with the main control board, the power interface is electrically connected with the main control board, the main control board is electrically connected with the battery jar, and a lithium battery is arranged in the battery jar.

The thermal printer is characterized in that the shell is provided with a touch screen and a thermal printer, the touch screen and the thermal printer are connected with the main control panel, four corners of the bottom of the shell are provided with base supporting points, the bottom of the shell is provided with bottom heat dissipation ports, and side heat dissipation ports are arranged on the side faces of the shell.

The invention has the following characteristics: the modular device design is adopted, the structure is simple, the installation is convenient, and a manufacturer can customize detection instruments with different hole site numbers according to the requirements of customers; the control system can independently control the heating film of each hot cover module, the heating sheet of each heating module and the fan of each heat dissipation module, so that later-stage debugging is facilitated to carry out temperature compensation and fluorescence compensation, the uniformity of temperature and fluorescence intensity is improved, and the accuracy of real-time monitoring is guaranteed. Meanwhile, if the detection instrument has redundant detection positions, the same user can simultaneously carry out constant temperature detection experiments at different temperatures; different users can detect the experiment under the condition that does not influence other people and be using, and both do not influence each other, have improved experimental efficiency and instrument rate of utilization.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a cross-sectional view of the present invention;

FIG. 3 is a left side view of the present invention;

FIG. 4 is a bottom view of the present invention;

in the figure: 100-a thermal cover module; 101-a light source module; 102 heating the module; 103-a heat dissipation module; 104-a detection module; 105-an interface module; 106-battery jar; 107-thermal printer; 108-a touch screen; 1-hot cover; 2-thermal cover locking; 3-sealing adhesive tape; 4-a housing; 5-heating the film; 6-copper sheet; 7-heating the test tube; 8-heat insulation plate; 9-a heat-insulating layer; 10-a base; 11-loosening and tightening screws; 12 an optical fiber holder; 13-a screw; 14-a gasket; 15-fixing the plate; 16-copper pillars; 17-a heating plate; 18-a heat sink; 19-a fan; 20-a hot lid spindle; 21-an optical path channel; 22-excitation filter; 23-a condenser lens; 24-a thermistor; 25-an excitation light source; 26-a secondary control panel support; 27 secondary control boards; 28-light source module holder; 29-fiber channel; 30-an optical fiber; 31-an emission filter; 32-a cassette; 33-a photodetector; 34-a main control board; 35-a fiber optic support; 36-main control board support; 37-USB-a interface; 38-USB-B data interface; 39-power interface; 40-side heat dissipation ports; 41-base fulcrum; 42-bottom heat sink; 43-division bars; 44-a sleeve; 45-a substrate; 46-a fitting portion; 47-groove.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

the utility model provides a portable constant temperature fluorescence detector of independent temperature control, includes shell 4, be equipped with a plurality of light source module 101, a plurality of heating module 102, a plurality of heat dissipation module 103, a plurality of detection module 104, hot lid module 100, interface module 105, main control board 34 and vice control panel 27 in the shell 4, be equipped with hot lid module 100 on the shell 4, the below of heating module 102 is equipped with heat dissipation module 103, one side of heating module 102 is connected with light source module 101, and the opposite side is connected with detection module 104, hot lid module 100, light source module 101, heating module 102, heat dissipation module 103 and main control board 34 are connected with vice control panel 27 respectively, main control board 34 is connected with detection module 104 and interface module 105 respectively, and the chip model of main control board 34 is STM32F103RCT 6.

Heating module 102 includes base 10, heat preservation 9, fixed plate 15, heating plate 17, screw 13, gasket 14 and copper post 16, copper post 16 is fixed on the inside bottom surface of shell 4, be fixed with fixed plate 15 on the copper post 16, fixed plate 15 adopts the aluminum alloy material, the center of fixed plate 15 is fixed with heating plate 17, the top of heating plate 17 is equipped with base 10, base 10 and fixed plate 15 pass through

screw

13 and 14 fixed connection of gasket, placed heating test tube 7 in the base 10, detect that test tube 7 chooses for use 0.2 ml's pcr pipe. The outer parcel of base 10 has heat preservation 9, and heat preservation 9 adopts black silica gel material, prevents that the temperature that 1 laminating zone 46 of hot lid produced from transmitting for reagent through base 10. The heating plate 17 is electrically connected with the sub-control board 27.

The base 10 comprises a ring cylindrical substrate 45 and a square sleeve 44, the sleeve 44 is arranged on the substrate 45, the inner wall of the sleeve 44 is attached to the outer wall of the heating test tube 7, and the heat conduction rate is guaranteed. The front and back of the sleeve 44 are provided with round openings corresponding to the light path channel 21 and the optical fiber channel 29, the size of the base 10 is the same as that of the heating plate 17, and the fixing plate 15 is a Z-shaped aluminum alloy plate. The bottom of the sleeve 44 is provided with an opening for placing the thermistor 24 for measuring temperature, and a gap between the thermistor 24 and the hole wall is filled with heat-conducting silicone grease. Corresponding to the sleeve wall of heating test tube 7 and silica gel heat preservation 9 both sides have the trompil that runs through around, and light path module 101 light path channel 21 is connected to one side, and the fibre channel 29 of detection module 104 is connected to the opposite side. The base 10 is made of aluminum alloy, and insulating coatings are added on the outer layers of aluminum alloy workpieces to ensure insulativity.

The heat dissipation module 103 comprises a heat dissipation sheet 18 and a fan 19, two ends of the heat dissipation sheet 18 are fixed on the copper column 16, the fan 19 is arranged below the heat dissipation sheet 18, the fan 19 is connected with the auxiliary control board 27, a bottom heat dissipation opening 42 is arranged below the fan 19, and the heat dissipation sheet 18 is fixed below the heating sheet 17. And heat conduction silicone grease is filled between the base 10 and the heating plate 17 and between the bottom of the heating plate 17 and the top of the radiating fin 18, so that the heat transfer efficiency is ensured. The heat sink 18 is made of copper.

The light path module 101 comprises a light source 25, an excitation filter 22, a lens 23 and a light path channel 21, wherein the excitation light source 25 is arranged at one end inside the light path channel 21, the lens 23 is arranged in the light path channel 21, the light path channel 21 is divided into two parts, one part is a cylindrical light channel conforming to the size of the light source 25 and is divided by the lens 23, the other part is a truncated cone-shaped channel with gradually reduced aperture, and the direction of the light path and the vertical direction of the base 10 form a certain acute angle. The bottom of the light path channel 21 is supported by a light source module support 28, the light source 25 is installed on a secondary control board 27, and the secondary control board 27 is fixed on the shell 4 through a secondary control board support 26 and mainly provides a power supply function. The light source 25 selects an LED with a wavelength of 470nm or 575 nm; the wavelength of the excitation light source optical filter 22 is 470 +/-10 nm or 575nm +/-10 nm; the lens 23 is a condensing lens, which ensures that the excitation light can smoothly pass through the gradually narrowed optical channel and enhances the reaction efficiency. Correspondingly, the wavelength of the emission filter 31 is 525nm + -10 nm or 630nm + -10 nm.

The heat cover 1 is connected with the shell 4 through a heat cover rotating shaft, a plurality of inverted quadrangular frustum pyramid shaped attaching parts 46 are arranged below one end of the heat cover 1, a heating film 5 and a copper sheet 6 are arranged on the lower part of each attaching part 46, the heating film 5 is connected with the auxiliary control board 27, a plurality of grooves 47 matched with the attaching parts 46 in shape are arranged on the shell 4, the grooves 47 are mutually separated through a separation strip 43, a heat insulation plate 8 is arranged at the bottom of each groove 47, the heat insulation plate 8 is made of glass fiber materials, the upper end of the heat insulation layer 9 is slightly higher than the upper end of the heat insulation plate 8, and the heat insulation plate 8 can prevent heat transfer between the heat cover 1 and the shell 4; the recess 47 and the heat shield plate 8 are connected to the upper end of the base 10 of the heating module 102. The same distance is maintained between each individual heating module 102.

The top of hot lid 1 is equipped with the draw-in groove, 4 tops of shell are equipped with hot lid kayser 2, hot lid kayser 2 and draw-in groove joint cooperation, laminating portion 46 is equipped with joint strip 3 all around, and joint strip 3 can be sealed the space when the lid is tight for hot lid 1, prevents that the heat from running off.

The detection module 104 comprises an optical fiber channel 29, an optical fiber holder 12, a loose screw 11, an optical fiber support 35, an optical fiber 30, a cassette 32, an emission filter 32 and a detector 33, wherein the optical fiber 30 is arranged in the optical fiber channel 29, one end of the optical fiber 30 is connected with an opening on the side wall of the base 10, the other end of the optical fiber 30 is connected with the cassette 32, two ends of the optical fiber channel 29 are fixed through the optical fiber holder 12, the optical fiber 30 in the optical fiber channel is fixed in position through the loose screw 11 on the optical fiber holder 12, the cassette 32 is installed on a main control board 34, and the emission filter 31 and the photodetector 33 are installed in the cassette 32. The reason that the optical fiber bundle with multiple inlets and single outlets or multiple inlets and multiple outlets is not used is that the fluorescence intensity has certain loss along with the bending and the length of the optical fiber, and the fluorescence intensity errors are different due to different deformation degrees of each optical fiber; meanwhile, the solution of guide rail plus single photodiode movement detection is not selected because the mechanical moving parts occupy a large space and the instability in movement can cause the increase of the detected fluorescence intensity error. It is preferable that the optical fiber 30 and the photodiode detector detect separately.

The interface module 105 is fixed on the side of the housing 4, the interface module 105 includes a USB-a interface 37, a USB-B interface 38 and a power interface 39, and the USB-a interface 37 and the USB-B interface 38 are connected to the main control board 34. The power interface 39 is electrically connected to the main control board 34, the main control board 34 is electrically connected to the battery container 106, and the battery container 106 contains a lithium battery, which can be used in the field without power supply. The USB-A interface 37 is used for reading USB flash disk transmission data, the USB-B interface 38 is used for connecting a computer for transmitting data, and the power supply interface 39 is used for supplying power.

A touch screen 108 and a thermal printer 107 are fixed on the shell 4, the touch screen 108 and the thermal printer 107 are connected with the main control board 34, and the touch screen 108 can display the temperature of each thermal cover 1 and the base 10 and the rotating speed of the fan 19; the thermal printer 107 can immediately print a detection result report. The heat dissipation structure is characterized in that four corners of the bottom of the shell 4 are provided with base supporting points 41, the bottom of the shell 4 is provided with a bottom heat dissipation opening 42, the side face of the shell 4 is provided with a side heat dissipation opening 40, and the base supporting points 41 are used for leaving a gap between the bottom heat dissipation opening 42 and an external plane, so that heat dissipation is facilitated.

After the thermal cover 1 is covered tightly, the attaching area 46 in the thermal cover 1 is tightly attached to the test tube cover of the heating test tube 7, the temperature is generally higher than the heating temperature of the heating sheet 17 by about 10 ℃, and the volume change of the reagent caused by the evaporation of the reagent is prevented from influencing the detection result. After the thermal cover 1 is covered, the thermal cover is fixed by a push type thermal cover latch 2, and a fixing part of the latch 2 extends into a groove of the thermal cover 1. The attaching part 46, the sealing rubber strip 3, the shell 4, the heat-insulating layer 9, the heat-insulating plate 8 and the parting strip 43 form a closed heating zone around the cover of the test tube 7, and each heating zone is guaranteed to be independent. After the heating test tube 7 is placed into the aluminum alloy base 10, the outer side of the tube wall of the heating test tube is just attached to the inner wall of the base sleeve barrel 44, and the aluminum alloy material has higher heat conduction efficiency than air, so that gaps are reserved as little as possible. The light source 25 and the photodetector 33 collect fluorescence signals at a certain period, and simultaneously display the fluorescence intensity variation curve of each well on the touch screen 108 for comparison of the results.

The invention has the following advantages: the modular device design is adopted, the structure is simple, the installation is convenient, and a manufacturer can customize detection instruments with different hole site numbers according to the requirements of customers; the control system can independently control the heating film 5, the heating sheet 17 and the fan 19 of each heating module 102, so that later-stage debugging is facilitated for temperature compensation and fluorescence compensation, the uniformity of temperature and fluorescence intensity is improved, and the accuracy of real-time monitoring is guaranteed. Meanwhile, if the instrument has redundant hole sites, the same user can simultaneously carry out constant temperature detection experiments at different temperatures; different users can detect the experiment under the condition that does not influence other people and be using, and both do not influence each other, have improved experimental efficiency and instrument rate of utilization.

Claims

1. The utility model provides a portable constant temperature fluorescence detector of independent temperature control, includes shell (4), its characterized in that: the LED lamp heating module is characterized in that a plurality of light source modules (101), a plurality of heating modules (102), a plurality of heat dissipation modules (103), a plurality of detection modules (104), a heat cover module (100), an interface module (105), a main control board (34) and an auxiliary control board (27) are arranged in the shell (4), the heat cover module (100) is arranged on the shell (4), the heat dissipation module (103) is arranged below the heating modules (102), one side of each heating module (102) is connected with the corresponding light source module (101), the other side of each heating module is connected with the corresponding detection module (104), the heat cover modules (100), the light source modules (101), the heating modules (102), the heat dissipation modules (103) and the main control board (34) are respectively connected with the auxiliary control board (27), and the main control board (34) is respectively connected with the detection modules (104) and the interface module (105).

2. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 1, wherein: heating module (102) includes base (10), heat preservation (9), fixed plate (15), heating plate (17), screw (13) and copper post (16), copper post (16) are fixed on the inside bottom surface of shell (4), be fixed with fixed plate (15) on copper post (16), the center of fixed plate (15) is fixed with heating plate (17), the top of heating plate (17) is equipped with base (10), base (10) and fixed plate (15) are connected through screw (13), placed heating test tube (7) in base (10), base (10) are equipped with heat preservation (9) outward, heating plate (17) and vice control panel (27) electric connection.

3. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 2, wherein: base (10) are including ring columniform basement (45) and square sleeve (44), establish on basement (45) sleeve (44), the inner wall and the outer wall of heating test tube (7) of sleeve (44) are laminated mutually, sleeve (44) front and back correspond light path (21) and fibre channel (29) department and all have circular opening, base (10) basement size is the same with heating plate (17) size, fixed plate (15) are the Z template.

4. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 2, wherein: the heat dissipation module (103) comprises a heat dissipation sheet (18) and a fan (19), two ends of the heat dissipation sheet (18) are fixed on the copper column (16), the fan (19) is arranged below the heat dissipation sheet (18), the fan (19) is connected with the auxiliary control board (27), and the heat dissipation sheet (18) is fixed below the heating sheet (17).

5. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 1, wherein: light path module (101) includes light source (25), excitation filter (22), lens (23) and light path passageway (21), excitation light source (25) are established in the inside one end of light path passageway (21), be equipped with lens (23) in light path passageway (21), light path passageway (21) divide into two parts, and partly for the cylindrical light passageway that accords with light source (25) size to lens (23) are the boundary, and another part is the truncated cone shape passageway that the aperture reduces gradually, there is light source module support (28) to support light path passageway (21) bottom, light source (25) are installed on vice control panel (27), vice control panel (27) are fixed on shell (4) through vice control panel support (26).

6. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 1, wherein: hot lid (1) links to each other with shell (4) through hot lid pivot, the below of hot lid (1) one end is equipped with a plurality of laminating portion (46), and the lower part of every laminating portion (46) all is equipped with heating film (5) and copper sheet (6), heating film (5) are connected with vice control panel (27), be equipped with a plurality of and laminating portion (46) matched with recess (47) on shell (4), separate each other through parting bead (43) between each recess (47), the bottom of recess (47) is equipped with heat insulating board (8), recess (47) and heat insulating board (8) link to each other with the upper end of heating module (102).

7. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 6, wherein: the top of hot lid (1) is equipped with the draw-in groove, shell (4) top is equipped with hot lid kayser (2), hot lid kayser (2) and draw-in groove joint cooperation, laminating portion (46) are equipped with joint strip (3) all around.

8. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 1, wherein: the detection module (104) comprises an optical fiber channel (29), an optical fiber fixer (12), a loose screw (11), an optical fiber support (35), an optical fiber (30), a cassette (32), an emission optical filter (32) and a detector (33), wherein the optical fiber (30) is arranged in the optical fiber channel (29), one end of the optical fiber (30) is connected with an opening on the side wall of the base (10), the other end of the optical fiber (30) is connected with the cassette (32), two ends of the optical fiber channel (29) are fixed through the optical fiber fixer (12), the optical fiber (30) in the optical fiber channel is fixed in position through the loose screw (11) on the optical fiber fixer (12), the cassette (32) is installed on a main control board (34), and the emission optical filter (31) and the photoelectric detector (33) are installed in the cassette (32).

9. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 1, wherein: the interface module (105) is fixed on the side face of the shell (4), the interface module (105) comprises a USB-A interface (37), a USB-B interface (38) and a power interface (39), the USB-A interface (37) and the USB-B interface (38) are connected with the main control board (34), the power interface (39) is electrically connected with the main control board (34), the main control board (34) is electrically connected with the battery jar (106), and a lithium battery is arranged in the battery jar (106).

10. The portable constant-temperature fluorescence detector capable of independently controlling temperature according to claim 1, wherein: the touch screen (108) and the thermal printer (107) are fixed on the shell (4), the touch screen (108) and the thermal printer (107) are connected with the main control board (34), four corners of the bottom of the shell (4) are provided with base supporting points (41), the bottom of the shell (4) is provided with a bottom heat dissipation opening (42), and the side face of the shell (4) is provided with a side heat dissipation opening (40).