66 results about "Microwave scattering" patented technology

Microwave imaging via space-time beamforming is carried out by transmitting microwave signals from multiple antenna locations into an individual to be examined and receiving the backscattered microwave signals at multiple antenna locations to provide received signals from the antennas. The received signals are processed in a computer to remove the skin interface reflection component of the signal at each antenna to provide corrected signal data. The corrected signal data is provided to a beamformer process that time shifts the received signals to align the returns from a scatterer at a candidate location, and then passes the time aligned signals through a bank of filters, the outputs of which are summed, time-gated and the power therein calculated to produce the beamformer output signal at a candidate location. The beamformer is then scanned to a plurality of different locations in the individual by changing the time shifts, filter weights and time-gating of the beamformer process. The output power may be displayed as a function of scan location, with regions of large output power corresponding to significant microwave scatterers such as malignant lesions.

The invention discloses a microwave scattering property test system based on a vector network analyzer. The microwave scattering property test system comprises the vector network analyzer, an antenna and a main control computer, wherein the vector network analyzer is used for generating a pulse radio frequency signal of a designated parameter under the control of the main control computer; the pulse radio frequency signal is transmitted by the antenna; and the vector network analyzer is also used for carrying out strobe treatment on a target echo signal received by the antenna to obtain microwave scattering property data within a designated area range. The vector network analyzer can be used for generating a narrowband pulse radio frequency signal with the frequency range covering wavebands of L, S, C, X, Ku and Ka; and the position of a strobe gate of a receiver is set by adopting a mode of fixed point test in pulse according to a test object. The microwave scattering property test system disclosed by the invention is convenient for field work and stable in performance and can be used for scattering property test of the ground background and a large-area camouflage net or the target scattering property test.

The invention relates to a simulation method for forest remote sensing data of a synthetic aperture radar, in particular to a quantified simulation method, belonging to the forest remote sensing technical field of the synthetic aperture radar. The simulation method comprises the following steps that: a geometrical model of a three-dimensional forest scene is built, a back scattering model of the radar is built, and SAR (Specific Absorption Rate) echo signal simulation and SAR image treatment are carried out. According to the invention, the echo signal simulation and image treatment processes are introduced in the quantified simulation process of the SAR forest remote sensing data, the overall acting process of a remote sensing system and the natural environment is reflected, and the overall link fidelity simulation from the observed object description and the action mechanism description of microwave scattering process to the acquisition of the original signal of the remote sensing system and ground image treatment can be accomplished.

The invention provides a forest biomass amount retrieval method based on collaboration of an optical reflection model and a microwave scattering model. The forest biomass amount retrieval method comprises the following steps: 1) establishing an optical-microwave radiation transmission collaborative model by comparing the difference between the optical reflection model and the microwave scattering model; 2) establishing an optical bidirectional reflection and microwave back scattering characteristic databank and a corresponding over-ground forest biomass parameter bank of a forest based on an individual growth model and the optical-microwave radiation transmission collaborative model; 3) respectively establishing a unisource optical model and a unisource microwave model for biomass retrieval based on an optical-microwave collaborative simulation databank; 4) through sensitivity analysis on optical and microwave key factors, confirming respective weights of the optical and microwave data in the collaborative model, thereby establishing an optical-microwave collaborative model for AGB retrieval. According to the forest biomass amount retrieval method, optical remote sensing data and microwave remote sensing data are combined, the advantages of the optical remote sensing data and the microwave remote sensing data in biomass retrieval are put into full play sufficiently, and the quantitative retrieval precision of the over-ground frost biomass amount is effectively improved.

The invention provides a method for typhoon monitoring and evaluation of the monitoring precision based on multi-source satellite data, belongs to the technical field, and solves the problem of limitation of a single satellite data source in the practical application in the prior art. The method for typhoon monitoring and evaluation of the monitoring precision based on the multi-source satellite data includes: (1) typhoon information data acquisition: obtaining typhoon visible light or infrared image information data by employing a Fengyun geostationary meteorological satellite, and obtaining typhoon microwave scattering data by employing a microwave scatterometer of an ocean satellite; (2) information data standardization processing: performing cloud atlas grayscale information extraction on a read base data source of visible light or infrared images of a Fengyun geostationary meteorological satellite partition map, performing geo-statistical interpolation on the microwave scattering data of the ocean satellite to obtain a final regional wind field map; and (3) typhoon center interpretation: determining the typhoon center. According to the method, accurate typhoon information is obtained by employing mutual confirmation and mutual supplementation of different satellite data.

The invention mainly belongs to the field of signal measurement and in particular relates to a signal nonlinear time-domain measurement and simulation method and application for nonlinear devices. A signal nonlinear time-domain measurement method caused by nonlinear devices such as power amplifiers, mixers and the like, does not need quadrature demodulation, directly measures the output waveforms of a nonlinear device at different input power of an input signal by using a digital storage oscilloscope to obtain a set of time-domain sequences. The time-domain sequences are transformed into analytic function forms by mathematical processing. When the period measured by the digital storage oscilloscope is N1, 0 to Nth-order Fourier transform is performed on the analytic function forms to obtain a complex function of the 0 to Nth-order Fourier series varying with input voltage, namely the 0 to Nth harmonics output by the no-linear device. The time-domain waveforms obtained by the measurement and simulation method are used to further obtain a segmented representing method of a fundamental wave and a measurement calibration method of a nonlinear microwave scattering parameter test instrument.

The invention relates to the technical field of voltage sensors, concretely relates to a passive high-temperature voltage sensor utilizing the microwave scattering principle and also a preparation method thereof, and helps to solve the problems that a conventional voltage measuring method has many defects in high-temperature and other severe environments. The passive high-temperature voltage sensor includes a cylindrical pedestal and a sealing membrane. A concave cylindrical cavity is disposed inside the pedestal. Four symmetrical cylinders are disposed in the middle of the concave cylindrical cavity, and the height of each inner cylinder is lower than the upper surface of the concave cylindrical cavity. The upper surface of the pedestal, the inner surface of the concave cylindrical cavity and the upper surface of each inner cylinder are all equipped with metal layers through sputtering. A silk screen on the upper surface of the sealing membrane is provided with a microstrip antenna through sputtering, a grounding plane is disposed on the entire lower surface of the sealing membrane through sputtering, and the lower surface is equipped with a rectangular coupling slit. The pedestal and the sealing membrane are bonded to form a microwave resonant cavity. The passive high-temperature voltage sensor is reasonable in design and high in sensitivity, exhibits great stability, can work for a long period of time in high-temperature, high-voltage and other severe environments, and belongs to a passive high-temperature ceramic voltage sensor for wireless measuring on the basis of microwave scattering.

A method of detecting small changes to a complex integrated circuit measuring RF / microwave scattering parameters between every pin over a wide frequency range. The data from a characterization of a known good integrated circuit is stored and compared to each subsequent integrated circuit of unknown background.

The invention discloses a secondary scattering characteristic simulation method of an SAR image. The method comprises the specific steps that 1, a three-dimensional imaging scene is built by using a three-dimensional model of an architecture target; 2, all triangular facets in the three-dimensional imaging scene are endowed with different microwave scattering attributes; 3, an interaction processof electromagnetic waves and the architecture target is simulated by using a ray-tracing algorithm, and simulated echo signals are generated; 4, the generated simulated echo signals are mapped to an SAR image plane, and a secondary scattering characteristic image is generated. According to the secondary scattering characteristic simulation method of the SAR image, based on the given three-dimensional imaging scene, echo signal characteristics of secondary scattering between the electromagnetic waves and the target are simulated, and a secondary scattering characteristic simulated image is generated; the secondary scattering characteristic simulation method of the SAR image can meet requirements of imaging mechanism analysis, target identification and parameter extraction of the SAR image of the architecture target.

The invention discloses an agitating fan for a microwave oven and belongs to components of cooking equipment through microwave heating. The agitating fan for the microwave oven comprises an agitating fan shaft and an agitating fan arranged on the agitating fan shaft, wherein the agitating fan shaft comprises a base and a middle shaft protruding from the center of the base; the agitating fan comprises an agitating fan main body forming a middle part of the agitating fan and a plurality of fan blades extending from the agitating fan main body, wherein one side of each fan blade is bent to one side to form a blade; a middle hole is formed in the center of the agitating fan main body; a shaft sleeve corresponding to the middle shaft is formed in the center of the agitating fan; an annular induced air baffle upwards protruding around the middle shaft on the base is formed; and a middle shaft assembly consisting of the induced air baffle, the middle shaft and the base is integrally formed. The agitating fan with the structure has the advantages of making the agitating fan rotate faster and more stably, effectively meeting the requirement of the agitating fan on the microwave scattering rotation speed, and improving the efficiency for scattering microwaves.

The invention discloses a microwave rotary tiller for eliminating root-knot nematodes, which comprises a flat-plate frame. Travelling wheels are disposed at the front end of the frame. Rotary blades are connected to the middle of the bottom of the frame, a microwave irradiation cavity is reserved around the rotary blades, the cross section of the microwave irradiation cavity is semispherical and provided with a bottom opening, the microwave irradiation cavity is connected with the frame, a plurality of microwave emitters are mounted on the outer front wall of the microwave irradiation cavity,a plurality of first microwave emitters are evenly distributed on the microwave irradiation cavity along the width direction, a plurality of second microwave emitters are mounted on the outer rear wall of the microwave irradiation cavity, the second microwave emitters are evenly distributed and horizontally arranged on the microwave irradiation cavity in the width direction, the wall of the microwave irradiation cavity is provided with microwave scattering through holes corresponding to the microwave emitters, vent holes are reserved on two sides of the upper portion of the microwave irradiation cavity and evenly distributed along the width direction of the microwave irradiation cavity, and the rotary blades are connected with a motor through a worm-and-gear and gears. The microwave rotary tiller can be used for eliminating the root-knot nematodes in soil within 30cm in depth sequentially during rotary tillage, and the elimination rate reaches 100%.

The invention relates to the technical field of active microwave remote sensing, in particular to a microwave scatterometer wind field inversion method and system based on maximum likelihood estimation, and the method comprises the steps: obtaining a backscattering echo signal received by a microwave scatterometer, and processing the backscattering echo signal to obtain a backscattering coefficient; on the basis of a maximum likelihood estimation method in combination with a geophysical model function, calculating a wind field inversion residual error and a wind field fuzzy solution of a corresponding wind vector unit through a backscattering coefficient; traversing a pre-established likelihood probability model based on the wind field inversion residual error of the wind vector unit to obtain the likelihood probability of the fuzzy wind field solution of the corresponding wind vector unit; and obtaining an L2B-level wind field data product through fuzzy removal and quality control. The invention provides a new method for analyzing the residual characteristics of different positions of the swath. A likelihood probability model function related to the position of the cradling amplitude is provided according to the change of observation information at different positions of the cradling amplitude.

The invention belongs to the technical field of ocean scattering echo analysis, and discloses a near-shore nonlinear sinusoidal wave microwave scattering characteristic analysis method, which comprises the following steps of: firstly, modeling near-shore environment nonlinear sea waves by adopting a simple and representative sinusoidal function based on a fluid dynamics Boussinesq model; and calculating the scattering coefficient of the near-shore nonlinear sinusoidal sea wave by using an analytical progressive model-second-order small slope approximation method; and finally analyzing the seawave scattering coefficient under different near-shore environment water depth change conditions. According to the method, nonlinear sea waves under the condition of near-shore water depth change, which cannot be simulated by a traditional linear sea wave modeling theory, are effectively assessed and analyzed, and compared with existing related researches under the condition of constant water depth for modeling of the traditional linear sea wave modeling theory, the method better meets the requirements of actual near-shore sea wave scattering mechanism analysis. Compared with existing linear sea wave modeling, the method better conforms to the actual near-shore marine environment.

The invention discloses a microwave three-dimensional imaging method based on multi-phase center observation constrained optimization. The microwave three-dimensional imaging method comprises the following steps: step A: imaging a target by a multi-phase center; pre-processing a received target echo signal after imaging; step B: carrying out distance attenuation factor compensation and antenna pattern correction processing on the pre-processed echo signal; step C: processing the compensated and corrected echo signal by adopting an observation constrained optimization method; and step D: extracting an observation region three-dimensional microwave scattering image, an observation region scene three-dimensional digital surface model or an observation region scene orthographic projection microwave image from a processing result of the step C. The method is applicable to microwave three-dimensional imaging of uniform synthetic aperture globe observation geometric description under the condition of different sampling constraints and different phase center quantities.

The invention discloses an oil film thickness inversion device of a ship borne microwave scatterometer. The device comprises a microwave scattering transmitter, a microwave scattering receiver and a net device, wherein the microwave scattering transmitter transmits microwaves on the surface of a target object, and scattering lights of various angles are generated; the microwave scattering transmitter receives the scattering lights of the target object, and the obtained scattering lights are finally transmitted to the net device; the net device is an important device of microwave radio frequency circuit measurement, microwave scattering curves can be obtained through the analysis of the net device, and the oil film thickness inversion is carried out through utilizing the microwave scattering curves and a scattering electromagnetic model; and the whole device can be convenient and flexible to operate through mounting a movable window and a sliding-rail-type support on a ship. The microwave scatterometer can be applied to oil spilling detection on the sea all day and all weather, the ship borne microwave scatterometer is convenient and flexible to detect the oil spilling, and simultaneously the oil film inversion by the microwave scatterometer is relatively accurate.

The invention relates to the field of remote sensing, The inventionand provides a wheat crop leaf area index inversion method based on microwave scattering and canopy simulation. The method comprisesthe steps that of S1, S1, the, based on actually measured crop and soil data, simulating microwave scattering conditions of wheat crops in each key growth period and soil in a research area through awheat crop growth period-based microwave scattering model, calculating a crop microwave scattering ratio according to the microwave scattering conditions, and performing spatial interpolation on the microwave scattering ratio to obtain a space crop microwave scattering ratio; S; s2, preprocessing the radar image of each key growth period of the wheat crops; o; obtaining HV and HH polarization backward scattering coefficients, inverting the wheat crop LAI pixel by pixel by using the wheat crop LAI inversion model based on canopy simulation based on the space crop microwave scattering ratio, andperforming mask by using the wheat crop distribution map to obtain a regional wheat crop LAI inversion result. According to the method, the regional wheat crop LAI inversion precision and efficiencyare improved, and a new technical means is provided for rapid, large-area, real-time and dynamic crop growth vigor and yield monitoring.

The invention discloses a system parameter design method for a multi-mode small satellite SAR in a scanning mode and a transmitting power optimization method. The system parameter design method is used for providing system working parameters such as the antenna size, signal bandwidth, pulse repetition frequency, scanning wave digit, wave position and the like for system simulation in the scanningmode. According to the transmitting power optimization method, the transmitting power is reduced by fully utilizing the characteristics of high wind speed and strong sea surface microwave scattering under the condition of proper wind direction, so that the starting time of each orbit when the multi-mode small satellite SAR works in an SAR mode is prolonged. A system parameter design result under the scanning mode, an ocean scene simulation result under conventional power and an ocean scene simulation result after power optimization are given. Results show that when the designed system parameters are adopted for system simulation, a good ocean scene imaging result is obtained. The simulation result also verifies that when the sea surface wind speed is high and the wind direction is proper,a good ocean scene imaging result can still be obtained by using the reduced transmitting power.

There is provided a microwave oven. In the microwave oven, a screw covering part is protruded toward an inside of a waveguide for an installation of a motor, a convergence preventing part is formed at a portion of a cavity with a shape corresponding to that of the screw covering part and at a location corresponding to that of the screw covering part, and an elevated portion formed by modifying a portion of the cavity in order to uniformly distribute microwave scattered by a stirrer fan. Therefore, the microwave can be distributed more uniformly about the cavity and thereby food can be cooked more evenly and speedily.

The invention relates to a microwave absorption spectrum measurement device based on thermo-acoustic effect. The microwave absorption spectrum measurement device comprises a microwave generator, a transmitting antenna, a sample tank, an ultrasonic detector, an amplifier, a data acquisition card and a computer, wherein the microwave generator, the transmitting antenna and the sample tank are arranged in sequence along a microwave input direction of the sample tank; and the sample tank, the ultrasonic detector, the amplifier, an oscilloscope and the computer are further arranged in sequence along an ultrasonic output direction of the sample tank. The invention further relates to a microwave absorption spectrum measurement method based on the thermo-acoustic effect and application of the microwave absorption spectrum measurement device based on the thermo-acoustic effect. The invention provides a method for directly measuring a microwave absorption coefficient and a microwave absorption spectrum, and the influences of microwave scattering and reflection are alleviated; and the thermo-acoustic effect is introduced into the measurement of the microwave absorption spectrum for the first time and substance concentration analysis can also be provided; and the method belongs to the technical field of the measurement of the microwave absorption spectrum.

The invention discloses a microwave radiation water-film-type drinking water sterilizing system. The microwave radiation water-film-type drinking water sterilizing system comprises a to-be-sterilizedwater storage chamber, a sawtooth-type microwave scatter plate, a microwave cavity, a built-in flow regulating valve, a microwave scattering cone, an upper water film forming plate, a magnetron pillar, a magnetron, a lower water film forming plate, a sterilized water storage area, an external valve, and a wall surface. The microwave cavity is divided to a microwave working area I and a microwave working area II by the upper water film forming plate and the lower water film forming plate. The lower part of the to-be-sterilized water storage chamber is a circular vertical water inlet. The lowerpart of the sterilized water storage area is a circular vertical water outlet. The upper water film forming plate is suspended by three sling chains. The lower water film forming plate is supported bythree inclined columns. The system has the advantages of high microwave utilization ratio, good drinking water sterilizing effect, and long service life of the magnetron.

The invention discloses a metamaterial focusing antenna for measuring spatio-temporal evolution of streamer electron density, which belongs to the technical field of metamaterial focusing antennas; the antenna comprises a planar dielectric lens array, a metamaterial metal unit, a focusing lens, a dielectric punching unit and a horn antenna. The horn antenna outputs a microwave scattering signal; the planar dielectric lens array converts signals into plane waves and outputs the plane waves, the plane waves are focused into a single wave beam through the metamaterial metal unit and the focusing lens between the planar dielectric lens array and the focusing antenna, so that high gain and high space synthesis efficiency of the transmitting array antenna are achieved. According to the invention, the planar dielectric lens is uniformly provided with air through holes, thereby achieving the phase compensation of electromagnetic waves transmitted by the circularly polarized horn antenna, and achieving a purpose of improving the gain and directionality of the circularly polarized horn antenna. The metamaterial metal unit is added between the planar dielectric lens and the focusing lens to converge to form a single wave beam, so that high gain and high space synthesis efficiency of the antenna are realized.

The present invention relates to one kind of small integral structure system of ground microwave radiation-scattering meter. The system is integral one of microwave radiation meter and microwave scattering meter, and features the microwave scattering meter of noise system with frequency band range designed to match that of the microwave radiation meter. Under the control of one main controlling and data processing unit, the microwave radiation meter and the microwave scattering meter operate alternately in time sharing mode, have emission leakage detection and receiving gain regulation, and share one receiver. The present invention is favorable to system integration and minimization, and has simplified system structure and lowered system cost.

The invention provides a long-distance radar microwave scattering receiving method, and relates to the technical field of surveying and mapping detection, and the method comprises the following steps: S1, setting a first receiving plate and a second receiving plate; S2, arranging a first microwave detector, a second microwave detector and a third microwave detector; S3, driving the second receiving plate to rotate around the first receiving plate during detection; S4, starting the first microwave detector and the second microwave detector to obtain microwave information, analyzing a detection signal, and decoding information content of a reference microwave signal; S5, detecting the detection information of a third microwave detector when the second receiving plate rotates by one circle; S6, acquiring a group of data with the largest information content difference with the reference microwave signal, and acquiring the position information of a third microwave detector; and S7, analyzing a microwave scattering value according to the position and the information content difference. The device is convenient to use and good in detection effect, effectively detects a microwave signal and a scattering value thereof, facilitates microwave signal correction, improves microwave detection accuracy, and can remotely read the microwave signal.

Microwave detection is nondestructive and rapid, the portability is good, but a severe development bottleneck exists on the aspect of humidity range detection. Most existing microwave moisture detecting systems adopt single frequency points for humidity measurement, are not wide in measurement range and are difficult to apply in practice. A microwave attenuation principle is utilized, microwave scattered signals of measured objects different in humidity under broadband frequency are obtained by using ultrawide-band antennae and serve as humidity regression training sample sets of the measured objects, and accordingly a measured object humidity regression model is established by utilizing a supervised machine learning method. The regression-type machine learning algorithm is adopted for data modeling, a cross validation mode is utilized to obtain optimum training parameters, accordingly the obtained model is optimized, and regression errors are smallest. The humidity range of fabrics which can be detected is greatly increased, and a foundation is laid for further devolvement of the microwave detection systems towards the application field.

The invention relates to a scattering matrix parameter detection system for microwave sensing. The system comprises a direct current parameter scanning module (1), a microwave circuit module (2), a processing display module (3) and a microwave sensor module (4) which are mutually combined to realize voltage control frequency parameter scanning, the values of the incident signal and the reflectionsignal or the straight-through signal are compared to obtain the variation trend of the reflection coefficient and the transmission coefficient in the microwave scattering matrix parameter, and the variation trend of the reflection coefficient and the transmission coefficient is calibrated to obtain the microwave scattering matrix parameter detected in real time; according to the invention, the function of displaying the scattering matrix parameter curve fed back by the microwave sensor and the value of the resonance point frequency on the screen in real time is finally realized. The inventionprovides the system capable of testing the scattering matrix parameter of a microwave device in an external complex environment. According to the specific technical mode, scattering matrix parametertesting of the microwave sensor is achieved through matching of single-chip microcomputer programming and a radio frequency circuit module.

The invention discloses a method for extracting deformation information of a railway line and a line area. The method comprises the following steps: acquiring longitude and latitude coordinates P1 corresponding to each mileage at the position of a center line of the railway line, GNSS continuous observation values G1 of a plurality of deformation reference point positions equipped with corner reflectors in an observation area and deformation information S1 of surface target body microwave scattering points under a geographic coordinate system in the observation area; according to the deformation information S1 of the microwave scattering points, taking the GNSS continuous observation values G1 of the reference point positions as constraint conditions, and fitting to obtain a deformation curved surface S2; constructing a line area influence range according to the fitted deformation curved surface S2 and the longitude and latitude coordinates P1 corresponding to each mileage at the position of the center line of the railway line; and extracting line deformation S3 in the line area influence range in the surface deformation of the observation area. According to the method, the deformation information of the railway line and the line area is separated by combining the advantages of GNSS continuous observation and microwave scattering body deformation observation, and the surface deformation observation precision of the railway strip area is improved.

The present invention relates to the electromagnetic reflection and transmission characteristic measurement technology field, and provides an arched support used for the material electromagnetic characteristic measurement in the wireless communication channel modeling. The arched support comprises a pedestal, a support body, a semi-circular sliding rail, a sliding block and a rotating driving mechanism. The support body is arranged on the pedestal, the semi-circular sliding rail is arranged on the support body, can rotate around the diameter and is equipped with the scales, the rotating driving mechanism is used to drive the semi-circular sliding rail to rotate around a shaft, and the sliding block is arranged on the semi-circular sliding rail and is equipped with a locking mechanism. The beneficial effects of the present invention are that the problems in the building material electromagnetic characteristic measurement in the wireless communication channel modeling that the distances can not be positioned flexibly and accurately and the angles can not be adjusted, are solved; the arched support is suitable for placing different types of antennas; the sliding rail can be moved, is convenient to disassemble and reassemble and can be used for researching the characteristics of the different building materials flexibly; the glass fiber reinforced plastics are used to manufacture the pedestal and the support body, so that the arched support has the characteristics of ultralow microwave scattering, high intensity and corrosion resistance, being insulating, etc.

The invention relates to a microwave crystal oscillator drying device for zero emission of desulfurization wastewater. According to the microwave crystal oscillator drying device, a spray end of a rotary spray head faces downwards and extends into a drying cylinder, a liquid inlet end is communicated with a crystal slurry solution, an air inlet end is communicated with one end of a heat exchanger,and the other end of the heat exchanger is provided with an air suction inlet communicated with the heat exchanger; the drying cylinder is vertically arranged, a spiral guide groove is formed in theinner wall of the drying cylinder from top to bottom, and a finished product discharging port is formed in the bottom of the drying cylinder; a magnetron device for emitting microwaves to the center is arranged around the drying cylinder, a vertical nested vibrating screen pipe corresponding to the magnetron device is arranged in the center of the drying cylinder, the outer ring of the nested vibrating screen pipe is a microwave scattering surface with a breathable film clamped inside, the inner ring of the nested vibrating screen pipe is a crystal oscillator element, and an air interlayer isreserved between the outer ring and the inner ring; the nested vibrating screen pipe extends out of the drying cylinder and is connected with a fan, air is exhausted outwards through an air exhaust pipeline, the air exhaust pipeline penetrates through a heat exchanger, and air sucked in through an air suction inlet is heated through the heat exchanger.