冷库节能与自动控制.doc

无锡职业技术学院毕业设计说明书(中英文翻译)The energy-conservation of freezer, with automaticallying control1 A present freezer of automatic control current situations Though the cold storage self-control having been popularized all round, but great majority cold storages putting particular emphasis on is only a safeguard face to face , the energy conservation having increased Wenku picking up the self-adjustment and cold storage measuring and controlling, to entire system relates that under the control of seldom or. Even if another aspect, already getting the all-round universal safeguard, before actual condition in working cant admit of no sanguine, ? pins up the cold storage self-control facilities having become ear of the deaf person even having become furnishing and decorating decorating front appearance only. The Shanghai cold storage association has done investigation in recent years to Shanghai area ammonia refrigerating system cold storage safeguard and autocontrol condition , concrete conditions has seen that are what form l shows. A spot of should inquire into a data as the leopard has reflected current cold storage self-control general situationForm what 1 shows a self-control interposes and runs status though the very good cold storage only having 5 tidal current and direction accounting for 9% of the number counting, but it is these cold storages to have represented a nowadays. With the development of electron technology, the self-control component is more and more advanced , changeable procedure controller (PLC) and the PC function are more and more strong , self-control procedure is more and more perfect, system optimization and the energy conservation consciousness are also more and more strong. The cold storage energy conservation and the autocontrol relation are more and more rapid and intense , need the cold storage energy conservation to be ready for and composing much better, do well in and be engaged in better the autocontrol vitally needing right away. Above-mentioned example adopted by five cold storages representing tidal current in the nowadays and advanced level has all got the pretty important effect to realizing cold storage energy conservation.2 How be ready for cold storage energy conservation autocontrolFundamental above-mentioned content starting point is the cold storage taking ammonia as all together style refrigeration working medium refrigerating system , is that refrigeration working medium decentralization, allows all together style , all together style refrigerating system cold storage to have got very big development , whose self-control degree overtops also sometimes the all together style refrigerating system cold storage taking ammonia as refrigeration working medium on behalf of a hydrocarbon with the thick gravy nowadays. Many working mediums are unlike cold storage of system of all kinds extensive use, content having enriched cold storage autocontrol tremendously, application in energy conservation at the same time also has provided the vast scope for ones ability to autocontrol in the cold storage.2.1 Cold storage energy conservation autocontrol is energy conservation under the control of procedure establishment and self-control component selecting and using from the content coming to study the autocontrol developing cold storage energy conservations relates that mainly whom. The firm , special field designing institute or capable unit as self-control component may assume cold storage energy conservation autocontrol research and develop equally. The firm and the designing institute make a contribution to some extent without exception already by now within that field. Cold storage energy conservation autocontrol can be developed exploitation commonly by firm and designing institute best (not bad firm give first place to, the designing institute coordinates) , perfects in the process of putting into effect using an unit the new product getting into form and 资料来源 360毕业设计网 grinding unceasingly to get rich.2.2 Energy conservation autocontrol specific items design prepares a cold storage putting composition into practiceThat a specific items energy conservation autocontrols puts process into practice sometimes is that the purpose checking ? K amendment , reaching energy conservation until according with design demand by designing , assembling debugging , pilot run , effect is extremely. While the project requires that content is changed into a ratio to some extent, may revise ? K at any time satisfying a request.The cold storage energy conservation sometimes requires that the advanced refrigeration switches over to prepare , right system mates , effective the words emergency measure and strict operation manage to manage to be put into effect, be requiring that the refrigeration technician goes ahead in the basis optimizing refrigeration process design right now, know well that energy conservation needs , be tied in wedlock this project characteristic , the flow chart designing out entire cold storage energy conservation autocontrol. Ability accomplishes whose electricity self-control design according to the self-control flow chart , the electricity self-control technician , being able to wield whose professional knowledge at the same time, makes self-control technological process be simplification and an optimization more. Cold storage energy conservation is a cold storage autocontrol important component , all cold storage autocontrol is composed of refrigeration and electricity two parts content without exception , ? K makes cold storage energy conservation be carried out to the letter only when ability makes cold storage autocontrol come into effect in the field of two under technicians making joint efforts.3 Cold storage energy conservation autocontrol pilot run is also one very important ring , echoes the usage unit and the special field firm in the pilot run keeping close connection , uses an unit to discuss working effect , deliberates amendment measure with special field firm and.Energy conservation is one of cold storage autocontrol purpose. 3.1 adjusts storehouse temperature adjustment in the past about that the storehouse temperature and the evaporation temperature adjust the parametric storehouse of 3.1.1 multiple spots temperature temperature giving first place to dyadic adjustment of place, correct evaporate the temperature not sometimes doing adjustment , very difficult to reach good energy conservation effect. The ideal storehouse temperature control mode is that wind and their air-out temperature is entering parameter with the storehouse mean temperature , the air cooler moving forward , works out appropriate under the control of procedure , measures by the fact that PLC is in progress. So-called Wenku adjusts the request being able to reach energy conservation , also can satisfy the need that some storehouse high-accuracy temperature adjusts, self own but the accuracy reaching 0.250 C requires that energy conservation makes an appointment with 10% at present.3.1.2 ? ps stop being unlike the ? diversity evaporates because K couplet operation can only work under evaporating the temperature with a with a systematic refrigeration compression engine evaporating the cold room of temperature temperature cold if ? K couplet work, with regard to relatively evaporate temperature higher cold right away be in no energy conservation operation state, should cold hot load increasingly be promoted to a higher post increasingly no energy conservation. Ought to try ones best to avoid this condition appearing. One machine reviews the cold storage method of work pair in freon refrigerating system , add the back pressure valve on time of high temperature warehouse air tube , add single check valve on time of low temperature warehouse air tube, be representative block of wood energy conservation method of work, do not respond to encourage but suitable abolish. 3.1.3 unexpected turn of events evaporates temperature adjustmentDiversity evaporates cold the temperature room if ? K couplet works as being able to only work under evaporating the temperature with a with a systematic refrigeration compression engine,to evaporating the temperature relatively, higher cold room is in block of wood energy conservation operation state right away , is cold hot room loads turn to be promoted to a higher post increasingly getting over block of wood energy conservation. Ought to try ones best to avoid this condition appearing. One machine reviews the cold storage method of work pair in freon refrigerating system , add the back pressure valve on time of high temperature warehouse air tube , add single check valve on time of low temperature warehouse air tube, be representative block of wood energy conservation method of work, do not respond to encourage but suitable abolish.3.1.3 unexpected turn of events evaporates temperature adjustmentSome one work state lower if evaporate temperature can use storehouse hot load and refrigerating system refrigerating output be parameter be in progress adjustment, then now that can reach energy conservation purpose can make energy adjustment be more rational. The sort Er Yan , refrigerating system evaporation implement and refrigeration compression engine equipment can satisfy maximal load need basically all. Load falls off but the refrigerating output can not make corresponding adjustment in time if the cold room is hot, the refrigerating output and hot load being that the refrigerating system evaporation temperature will may act in responses reduces , uses a compression engine reach a new balance burning. The lessening evaporating the temperature has increased but the refrigerating output evaporating an implement conversely but , has faced the hot load that self own cuts down taking form surely frequently opening the consequence staying. Evaporate temperature 10 C per change, electric energy about 3 5% acting in responses adding or subtracting. Be energy conservation on making system burn in another ideal balance of ? if raising the evaporation temperature in time,have avoided freely not having achieved not only, having decreased by the refrigeration compression engines frequently starts , is the energy conservation measure achieving two things at one stroke.Not changeable fundamental refrigerant rate of flow rate of flow evaporating an implement adjusts 3.1.4 changeable rate of flow adjustment ammonia in the past refrigerating system; Freon system evaporates the implement refrigerant rate of flow , great majority achieve simple proportion measures. The air cooler air mass flow great majority do not measure or speed and the electric fan platform number measure only when two. This two kinds parametric rate of flow adjustment all are cold the adjustment assigning the equipment refrigerating output and storehouse temperature direct relevance , one of the content being also that the cold storage energy conservation self-control responds to in taking seriously with the storehouse.3.1.5 sets up right under the control of accuracy and adds the storehouse temperature setting up the commodity and different storage period controlling the different storehouse , different stock out of gauge having no equal to and their under the control of accuracy request. Set off from the energy conservation angle, the storehouse temperature ought to take height not choosing low , the mild high-accuracy controlling accuracy ought to fetch the warehouse taken height , insisted to run after face to face unnecessarily low low controls as long as not affecting the commodity quality.To the cold room of many ? storehouse temperature under the control of, except original storehouse temperature setting value, suitable add set up Kuwen transfinite controlling value. This pair of factors storehouse temperature adjusts deflect but premature bringing into service being able to achieve when refrigerating system needs bringing into service , incapable because of ? pins up the storehouse temperature; Can not make cold according to reality that time at intervals, refrigerating system stops working untimely Ding , fully utilizes now having energy ? K avoid equipment or systematic frequently open Ding.3.1.6 interpose avoid meeting high ? o operation under the control of electric power short-supplied be the universal phenomenon that current all parts of the country there exists in everywhere, huge bad especially heavy electric power of power consumption ? o grain is short-supplied , the electric charge ? o grain price differences puts into effect in a lot of city and price differences play big as early as successive steps for this purpose. Under the premise not affecting commodity mass, the cold storage is set up avoiding meeting high ? o operation , beneficial to the electrified wire netting cuts ? o repair a valley , help overall situation energy conservation on macroscopic view; Microcosmic Er Yan operation also beneficial to reducing a cold storage cost.3.2 cold room relative humidities adjust cold room relative humidity adjustment and the temperature adjusts the method similarity repeating description unnecessarily. But in general cold room relative humidity is in 85 the relative humidity that the also a little bit cold room demands is lower than or the relative humidity higher than the be 98%, but some crops of relative humidity kind of quality warehouse being range , for instance some gases turn to obj1 = 位 ? exchange the warehouse request demands 45% to be 40 between 95%. During the period of high relative humidity adjustment and low relative humidity adjustment, Youyin attaches importance to energy conservation measure.3.2.1 high relative humidities adjust the adjustment demanding the cold room to high relative humidity , are going try ones best to reduce the logarithm averages difference in temperature (2 advisable K) between the refrigerant temperature and the storehouse temperature, return refrigerating system back when being necessary but adopt to be loaded with the cold agent first; May adopt air defrosting ? K besides with defrosting water restoring to the storehouse. That this two measure is given by autocontrol being put into effect, is effective energy conservation method , the domestic trade headquarter has not been 20,000 tons of Long Kou City gas that the research institute designs obj1 exchange a warehouse being a very good example of one 17 .3.2.2 low relative humidities adjust the adjustment demanding the cold room to low relative humidity , controlling also should be ready for two aspect mainly. One is on the basis selecting and using dehumidification method and dehumidification machine stopping bringing quantity of heat into cold room to the full, hot few cold ? p rooms load controlling good dehumidification while procedure, reaching the relative humidity request. Its two is to avoid air current organizing the wet load controlling fever of taking now and then entering unnecessary outside; Once had the wet low one ? low temperature crops kind of quality warehouse, wet load roughly accounts for about 35% of plain meter ? load from invading the heat within being put in storage outside.3.3 measures about providing liquid way3.3.1 direct swelling is for liquids expanding directly to be for liquids being that great majority thick gravies pin up the confession liquid method that ammonia system adopts on behalf of hydrocarbon (include freon) system and ? . This provides liquid method with adopt the heating power expansion valve to provide liquid in the past basically , self problem, has no way to realize the energy conservation purpose since choosing the type , adjustment and product. Electron expansion valve appearing measures combining with selecting parametric Kuwen of temperature much , can realize energy conservation operation fairly good, sort but energy conservation 10%. But the thick gravy generation hydrocarbon refrigerating system heating power expansion valve product already be commensurate to maturity and still have the special-purpose PLC Kuwen controller, for a variety of reasons, adopt extension , wait for to increase energy not yet commonly in cold storage refrigerating system. Working hot shot degree of ammonia refrigerating system evaporation implement is not big , degree of difficulty is under the control of relatively bigger , there is no at present still mature ammonia using electron to expand ? ? valve product.The system 3.3.2 gravity is applied in being for liquid gravitys being for liquid systems being in old ammonia refrigerating system chasing the ashamed quilt ammonia pump very broadly, afterwards providing liquid is substituted. Gravity is for liquid systems not needing to consume electric power transmission although operation is inconvenient, as long as matching it with right autocontrol, operation being one kind of energy conservation beyond doubt. Xiamen commerce cold storage plant stream state melts the system freezing a device having adopt R22 gravity to provide liquid , Shanghai 21 generation writes down a cold storage adopt ammonia refrigeration gravity to be for liquid system ? Ks having realized autocontrol. How to be ready for gravity being for liquid system autocontrol energy conservations running ? K carry out quantitative analysis and improve unceasingly , be one ? aspect being worthy for us to pay close attention to. Circulatory system middle applies 3.3.3 liquid pump confession liquid liquid pump to ammonia refrigerating system again very broad; The upper world writes down Shanghai in the 70s foreign trade the cold storage freezing five ten thousand tons of factories is R22 liquid pump recycling refrigerating s