Mathau o synhwyrydd nwy a eu ceisiadau mewn nwy canfod a monitro offer
Gyda y datblygu o y petrocemegol diwydiant, y math a cais ystodau o flammable, ffrwydrol a gwenwynig nwyon wedi wedi cynnydd. Unwaith hyn nwyon gollwng yn ystod cynhyrchu, cludiant, a defnydd, bydd achos gwenwyno, tân a ffrwydrad damweiniau, o ddifrif peryglu pobl's bywydau a eiddo diogelwch. Due i y diffusibility o y nwy itself, ar ôl A gollyngiad yn digwydd, y nwy bydd gwasgariad ar hyd y ddaear arwyneb o dan gweithredu allanol gwynt grym a mewnol crynodiad graddiant% 2c ffurfio A hylosgi ffrwydro neu gwenwynig perygl parth yn y damwain safle, a ehangu y ardal beryglus.
Once nwy nwy gollyngiadau damwain digwydd, 2c gohebu mesurau rhaid fod cymryd cyn cyn fel bosibl i lleihau y damwain loss. Amserol a dibynadwy canfod y o sicrwydd nwyon yn y aer, amserol a effeithiol adfer mesurau, a cywir gwaredu dulliau i lleihau damweiniau achosi gan yn amodau angenrheidiol ar gyfer osgoi eiddo mawr a anafedigion. Mae hyn puts ymlaen gofynion uwch ar gyfer nwy canfod a monitro offer. Fel an pwysig nwy synhwyrydd, nwy synhwyrydd wedi mawr datblygu yn yn ddiweddar blynyddoedd. datblygu o synhwyrydd gwneud ei cais mwy a mwy helaeth.
Nwy Synhwyrydd Trosolwg
Foreign gwledydd dechrau ymchwil a datblygu nwy synwyryddion yn y 1930s. Yn y past, nwy synwyryddion yn yn bennaf defnyddiwyd ar gyfer y canfod a larwm o glo nwy, 2c nwy yn mwyngloddiau. Yn presennol% 2c y mathau o nwyon hynny angen i yn wedi'u canfod wedi wedi ehangu o y gwreiddiol lleihau nwyon (H2% 2c C4H10, CH4) (CO, NO2% 2c H2S, NO, NH3% 2c PH3).
Mae yn llawer math o nwy synwyryddion. According i y gwahanol synhwyro nwy deunyddiau a nwy-synhwyro nodweddion used, mae'n gall fod rhannu lled-ddargludyddion math, solid electrolyte math, math, cyswllt math, polymer math, ac ati.
% 0aSemiconductor nwy synhwyrydd
This synhwyrydd bennaf defnyddiau lled-ddargludyddion nwy-sensitif deunyddiau. Ers y lled-ddargludyddion metel ocsid nwy synhwyrydd daeth allan yn 1962% 2c mae'n wedi wedi manteision uchel sensitifrwydd a cyflym ymateb, a HAS un o y mwyaf a y rhan fwyaf eang defnyddio synwyryddion yn y byd. According i y ffyrdd gwahanol o canfod y y nwy-synhwyro nodwedd maint, mae'n rhannu i dau math: resistive type a heb fod yn gwrthsefyll math.
Resistive semiconductor gas sensor works by detecting the change of gas sensor with gas content. Metal oxide ceramic gas sensitive materials are mainly used. With the research and development of new materials such as composite metal oxides and mixed metal oxides in recent years, the characteristics and application range of this gas sensor have been greatly improved. For example: WO3 gas sensor can detect NH3 concentration range from 5ppm to 50ppm, ZnO-CuO gas sensor is very sensitive to 200ppm CO.
Non-gwrthiannol lled-ddargludyddion synwyryddion gwaith ar yr egwyddor y cyfredol foltedd o y y nwy synhwyrydd newidiadau gyda y nwy cynnwys. Mae yn bennaf MOS deuod math synhwyrydd. Rhan o y canfod nwyon yn yn combustible nwyon fel hydrogen a silane.
Solid electrolyte gas sensors use solid electrolyte gas-sensing materials as gas-sensing elements. The principle is that the gas-sensitive material generates ions when passing through the gas, thereby forming an electromotive force, and measuring the electromotive force to measure the gas concentration. Due to the high conductivity, good sensitivity and selectivity of this sensor, it has been widely used, and has entered almost all fields of petrochemical, environmental protection, mining, etc., second only to metal oxide semiconductor gas sensors. For example, YST-Au-WO3 for measuring H2S, NH plus 4CaCO3 for measuring NH3, etc.
Contact hylosgiad nwy synhwyrydd
It can be divided into direct contact combustion type and catalytic contact combustion type. Its working principle is: when the gas-sensitive material is energized, the flammable gas is oxidized and burned under the action of a catalyst, and the heat generated heats up the heating wire, thereby changing its resistance value, and measuring the change of resistance to measure the gas concentration. This sensor can only measure combustible gases and is insensitive to non-combustible gases. For example, sensors made by coating active catalysts Rh and Pd on Pt wire have broad-spectrum characteristics, that is, they can detect various combustible gases. The contact combustion gas sensor is very stable at ambient temperature and can detect most flammable gases with the lower limit of explosion. It is widely used in the monitoring and alarm of flammable gases in petrochemical plants, shipyards, mine tunnels, bathrooms, kitchens, etc.
Polymer nwy synhwyrydd
Gas sensors using polymer gas-sensing materials have been greatly developed in recent years. When the polymer gas-sensing material encounters a specific gas, its physical properties such as resistance, dielectric constant, material surface acoustic wave propagation speed and frequency, and material weight will change. There are mainly phthalocyanine polymers, LB film, phenylcyanine acetylene, polyvinyl alcohol-phosphoric acid, polyisobutylene, aminoundecyl silane, etc. Polymer gas-sensing materials play an important role in the detection of toxic gases and food freshness due to their ease of operation, simple process, good selectivity at room temperature, low price, and easy combination with microstructure sensors and surface acoustic wave devices. According to the gas-sensing properties of the materials used, this type of sensor can be divided into: polymer resistive gas sensors that measure gas concentration by measuring the resistance of gas-sensing materials; concentration battery-type gas sensors that measure the electromotive force to determine the gas concentration by forming a concentration cell when the gas-sensing material absorbs gas; surface acoustic wave gas sensors that are made based on the principle that the propagation speed or frequency of sound waves on the surface of the material changes after the gas-sensing polymer absorbs gas; The polymer gas sensor has high sensitivity to specific gas molecules, good selectivity, simple structure, can be used at normal temperature, and can supplement the deficiencies of other gas sensors.
