外文翻譯---果蔬太陽能干燥脫水裝置設(shè)計

1、<p>　　果蔬太陽能干燥脫水裝置設(shè)計</p><p>　　摘要：根據(jù)廣式?jīng)龉母稍锾匦裕O(shè)計開發(fā)了一套小型全天候太陽能干燥設(shè)備，并對該設(shè)備進(jìn)行應(yīng)用試驗研究，對比分析不同涼果在研制的干燥設(shè)備中的實際應(yīng)用結(jié)果，與傳統(tǒng)的自然日曬干燥、熱風(fēng)干燥相比的優(yōu)勢，尋找設(shè)備干燥涼果最佳工藝條件，對工廠的實際運作起指導(dǎo)作用。</p><p>　?。?）該小型裝置特點是利用對 V 型太陽能集熱板進(jìn)行

2、改造，使之成為既可輸送熱風(fēng)，也可實現(xiàn)儲存熱量于熱水中，該設(shè)備由集熱板，干燥室，小型風(fēng)機，儲熱水箱，蛇行風(fēng)管，水泵，溫濕度感應(yīng)器，小型換熱器，自動控制閥門及空氣過濾裝置組成，有完整的一套集熱收集太陽能系統(tǒng)和熱風(fēng)干燥系統(tǒng)。白天干燥過程中，風(fēng)從集熱器底部經(jīng)加熱后進(jìn)入干燥室干燥，排出的熱風(fēng)經(jīng)鼓風(fēng)機重新進(jìn)風(fēng)，當(dāng)干燥室內(nèi)溫度過高時，自動控制閥將打開，水由集熱器加熱收集熱量儲存于保溫水箱中；夜間當(dāng)溫度感應(yīng)器感應(yīng)干燥室內(nèi)部溫度過低，由控制閥中斷集熱器進(jìn)

3、風(fēng)口，風(fēng)由水箱中蛇形風(fēng)管由水加熱進(jìn)入干燥室，之后類似于白天干燥過程；白天重新開始時，控制單元驅(qū)動控制閥關(guān)閉蛇形風(fēng)管進(jìn)風(fēng)口，打開集熱器進(jìn)風(fēng)口，又開始集熱板熱風(fēng)干燥過程，儲熱水箱又可開始儲存熱能，周而復(fù)始，實現(xiàn)連續(xù)干燥操作；氣候條件不佳時，可利用水箱中的電熱絲加熱水，通過蛇形風(fēng)管實現(xiàn)熱風(fēng)干燥過程。該太陽能連續(xù)供熱式干燥設(shè)備，能連續(xù)供熱、全天候工作、成本低、結(jié)構(gòu)簡單、干燥效率且熱利用效率高。</p><p>　?。?）

4、試驗中采用的自主研制太陽能干燥設(shè)備，空氣對流方式為自然對流和強制對流方式，研究了樣品的干燥特性，在達(dá)到干燥要求的情況下，自然對流干燥時間需 14h，強制對流干燥所需時間為 12h，遠(yuǎn)遠(yuǎn)低于傳統(tǒng)日曬干燥（50h），自然對流干燥整個干燥過程樣品的平均 Deff值為 1.39×10-6m2/s，強制對流干燥過程中樣品的平均 Deff值為1.26×10-6m2/s，兩種干燥方式干燥的水分?jǐn)U散能力都比較均勻。</p>

5、;<p>　?。?）干燥設(shè)備自然對流干燥和強制對流干燥兩種干燥方式下，以干濕梅作為試驗樣品，研究樣品的理化品質(zhì)及感官特性，試驗結(jié)果表明，隨著濕基濕含量的降低，處于不同層的梅子成品時的總糖、總酸和鹽含量均有不同程度的增加，在樣品色澤方面，非酶褐變使各層樣品的 L*值和 a 值上升，但對于 b 值而言，果皮果肉在干燥過程中趨勢相反（果皮 b 值下降，果肉 b 值上升），達(dá)到出廠產(chǎn)品品質(zhì)要求。通過對干燥設(shè)備不同干燥方式不同物料層

6、，樣品理化及感官特性的研究，試驗結(jié)果表明，自然對流方式通過適當(dāng)?shù)恼{(diào)整物料層的位置，對于樣品的品質(zhì)會有一定程度的提高，而強制對流方式由于干燥相對比較穩(wěn)定，不需要通過調(diào)整物料層的位置來提高樣品的品質(zhì)。</p><p>　?。?）太陽能干燥設(shè)備不同干燥方式下的應(yīng)用研究表明，相對于自然日曬干燥、溫室、烘箱干燥等傳統(tǒng)干燥方式，太陽能干燥設(shè)備存在明顯優(yōu)勢，干燥時間明顯縮短，最多可以縮短 76%，設(shè)備干燥總效率為 63.4%，

7、干燥過程環(huán)保節(jié)能；干燥環(huán)境高溫低濕，產(chǎn)品品質(zhì)干燥效率和生產(chǎn)成本均有不同程度的提高，可以滿足包括梅子等熱敏性物料。</p><p>　　在內(nèi)的多種農(nóng)產(chǎn)品的干燥要求。</p><p>　?。?）樣品干燥至目標(biāo)水分含量時，自然日曬大約需要 50h，溫室干燥約為 30h，烘箱熱風(fēng)干燥需要 12h，自制太陽能干燥設(shè)備自然對流方式及強制對流干燥方式耗時分別為 14h 和 12h。強制對流、烘箱干燥、自

8、然對流、溫室干燥與自然日曬干燥在 12h 內(nèi)濕含量分別降至 58.08%、57.08%、60.21%、64.32%、69.22%。在干燥到相同的濕基濕含量（最終產(chǎn)品）的時候，五種干燥方式干燥產(chǎn)品水分活度均到達(dá)儲藏要求，產(chǎn)品品質(zhì)均達(dá)到了產(chǎn)品出廠的要求，綜合而言，太陽能干燥設(shè)備干燥效果最佳。</p><p>　　綜上分析可以知道，利用自制廣式?jīng)龉⌒吞柲苋旌蚋稍镌O(shè)備研究溫室、自然對流和強制對流等干燥方式與傳統(tǒng)熱風(fēng)

9、干燥與自然日曬干燥的差異，本試驗為小型太陽能全天候干燥設(shè)備對工廠的加工生產(chǎn)中的實際應(yīng)用提供理論依據(jù)。</p><p>　　太陽輻射具有分散性和斷續(xù)性的特點，是太陽能利用中最大的困難。如何有效地收集蓄積太陽能，對太陽能的利用效率有著非常重要的影響。太陽能在建筑采暖和農(nóng)業(yè)日光溫室的應(yīng)用中，太陽墻是太陽能收集和蓄積的關(guān)鍵技術(shù)，是實現(xiàn)太陽能-建筑-體化的重要組成部分，也是世界各國學(xué)者普遍研究和關(guān)注的課題。因此，太陽墻的研

10、究有著非常重要的意義。本文綜合分析了國內(nèi)外“太陽墻”的研究現(xiàn)狀，集多孔介質(zhì)復(fù)合Trombe墻和太陽能多孔集熱墻優(yōu)點為一體，設(shè)計了一種多孔介質(zhì)太陽墻，并采用數(shù)值模擬的方法對多孔介質(zhì)太陽墻的傳熱機理及應(yīng)用進(jìn)行了研究。</p><p>　　從簡化的角度出發(fā)，建立描述多孔介質(zhì)太陽墻傳熱與流動特性的一維數(shù)學(xué)模型，對作為媒質(zhì)的空氣在多孔墻內(nèi)的流動，以及與多孔墻之間的換熱機理進(jìn)行了初步的研究。結(jié)果表明:多孔墻能收集與蓄積太陽能

11、，并加熱空氣;降低多孔墻入口空氣速度，能夠提高空氣的溫度;在保證所需的太陽輻射吸收率的條件下，增大多孔墻的孔隙率與滲透率，能夠提高空氣的溫度;當(dāng)多孔固體材料采用金屬與非金屬材料時，出口空氣溫度有著較大的差別。當(dāng)多孔骨架材料采用鋁時，空氣的溫升幅度較大，出口空氣溫度高，而采用巖石，空氣的溫升幅度較小。在實際應(yīng)用中，應(yīng)合理選擇滲透率和多孔骨架材料，盡可能地降低初投資。</p><p>　　基于對多孔墻的熱分析，為降低

12、多孔墻與環(huán)境之間的輻射與對流換熱損失，從結(jié)構(gòu)上對多孔墻進(jìn)行改進(jìn)，設(shè)計了一種新型的多孔太陽墻系統(tǒng)。在多孔墻的集熱面與環(huán)境之間設(shè)玻璃蓋板，形成玻璃通道。利用玻璃通道的“溫室效應(yīng)”降低熱損失和收集熱空氣。在多孔墻內(nèi)側(cè)通道內(nèi)設(shè)有風(fēng)機，在風(fēng)機的作用下，室外空氣流入多孔墻，與多孔墻進(jìn)行熱交換后，被加熱到一定的溫度，用于冬季的供暖?；诙S穩(wěn)態(tài)Navier-Stoke方程、飽和多孔介質(zhì)Brinkrnan-Forchheimer Extended Da

13、rcy模型和能量雙方程模型，對這種設(shè)有風(fēng)機并附加玻璃通道的新型的多孔太陽墻系統(tǒng)內(nèi)的傳熱與流動特性進(jìn)行數(shù)值模擬。結(jié)果表明:風(fēng)機的設(shè)計對系統(tǒng)內(nèi)溫度場和流場有較大的影響;降低空氣入口流速，可減小空氣流動阻力，提高多孔墻的集熱效率;附加玻璃通道的多孔太陽墻可減小長波輻射損失，并具有收集熱空氣的作用。因此，它具有較高的集熱效率。</p><p>　　設(shè)計了一種多孔蓄熱墻-溫室系統(tǒng)。將溫室北墻設(shè)計為由“半透明”的等徑、均勻的

14、多孔球堆積而成的多孔墻，能吸收和蓄積太陽能，加熱溫室空氣，而且能夠主動地調(diào)節(jié)溫室內(nèi)的熱環(huán)境。將溫室與多孔蓄熱墻結(jié)合起來，充分發(fā)揮兩者的作用。從而提高了溫室的太陽能利用效果。借助帶內(nèi)熱源的飽和多孔介質(zhì)能量雙方程模型和Brinkman-Forchheimer Extended Darcy模型以及k-。紊流模型，對該太陽能溫室系統(tǒng)的傳熱與流動特性進(jìn)行預(yù)測。在此基礎(chǔ)上，進(jìn)一步模擬分析了孔隙率分層多孔墻對溫室系統(tǒng)特性的影響。結(jié)果表明:溫室系統(tǒng)的入

15、口參數(shù)和多孔墻的結(jié)構(gòu)對溫室內(nèi)的溫度場、流場和壓力場有較大的影響。因此，針對一定結(jié)構(gòu)的溫室系統(tǒng)，應(yīng)根據(jù)溫室熱環(huán)境的要求，合理地設(shè)計多孔墻本體，調(diào)節(jié)風(fēng)機的運行工況。</p><p>　　設(shè)計了兩種通風(fēng)方式下的多孔太陽墻采暖系統(tǒng)。采用飽和多孔介質(zhì)Brinlanan-Forchheirner Extended Darcy模型、帶內(nèi)熱源的能量雙方程模型以及k-。紊流模型對采暖系統(tǒng)內(nèi)的傳熱與流動特性進(jìn)行計算、分析和比較。結(jié)果

16、表明，多孔太陽墻采暖系統(tǒng)的送排風(fēng)方式，對采暖房內(nèi)的溫度場、流場有很大的影響，它直接影響到系統(tǒng)的保溫作用，對多孔墻的熱利用率有較大的影響。因此，在實際應(yīng)用中，應(yīng)合理地設(shè)計多孔太陽墻采暖系統(tǒng)，提高多孔墻的熱利用率，從而降低多孔墻的熱價。</p><p>　　對局部和斜坡地板送風(fēng)式多孔太陽墻采暖系統(tǒng)內(nèi)的傳熱與流動進(jìn)行了數(shù)值模擬，得到了兩種系統(tǒng)內(nèi)的溫度分布、流場分布。分析了架空地板的結(jié)構(gòu)、地板送風(fēng)口尺寸對采暖房內(nèi)溫度場和

17、流場的影響;分析了建筑南墻對室內(nèi)溫度的影響。結(jié)果表明:采用地板送風(fēng)方式，能夠保證采暖房內(nèi)均勻的溫度場和流場;采用斜坡式地板送風(fēng)方式，更有利于保證各送風(fēng)口流量分布均勻。在實際應(yīng)用中，應(yīng)注意建筑承重墻的隔熱，防止“熱蝕”現(xiàn)象發(fā)生。</p><p>　　針對多孔墻的結(jié)構(gòu)特點，采用描述填充結(jié)構(gòu)的多孔介質(zhì)模型，進(jìn)一步分析了多孔墻的結(jié)構(gòu)特性。結(jié)果表明:增大顆粒直徑和孔隙率能夠降低系統(tǒng)的阻力。這一結(jié)果提供了優(yōu)化多孔墻的結(jié)構(gòu)參數(shù)

18、。</p><p>　　設(shè)計了多孔太陽墻測試系統(tǒng)，該系統(tǒng)能用于測試多孔太陽墻系統(tǒng)的阻力，多孔墻的吸收率和體積換熱系數(shù)等特性參數(shù)。但由于太陽輻射的模擬是一個難點，因此，為了精確測試多孔墻的熱性能，還需對測試系統(tǒng)進(jìn)行改進(jìn)。</p><p>　　關(guān)鍵詞：太陽能干燥，強制對流，溫室干燥</p><p>　　Fruit and vegetable solar drying d

19、ehydration unit design</p><p>　　ABSTRACT：In this paper, a small scale solar drying equipment was designed based on the study of drying characteristics of preserved fruits of “Study of Drying Characteristics

20、of Preserved Fruit”.</p><p>　　The test and applied research of the solar drying equipment was studied and the application of the results of different preserved fruits in the development of the solar drying e

21、quipment were analyzed compared to the traditional natural sun drying, hot air drying. The optimum conditions for drying preserved fruits under the solar drying equipment was to be find out and the advantages of the dryi

22、ng equipment was also to be find out. The actual operation of the solar equipment for plants was invest</p><p>　　(1) The characteristics of the small scale solar drying devices is the reform of the V-plate s

23、olar collectors, making it not only transported hot air, but also stored heat in water. The device was comprised of heat collector, drying room, small fan, water storage tank, blast pipe, pumps, temperature and humidity

24、sensors, small heat exchangers, control valves and air filter. And it composed of a complete set of system to collect solar energy and hot air drying system. </p><p>　　Drying process during the daytime, the

25、hot air was blew into the drying chamber from the bottom of the collector. Hot air discharged from the chamber was sent back into the chamber by the blower. When the drying chamber temperature was too high than desire, t

26、he automatic control valve opens to stored heat to the water tank by the heating collectors. </p><p>　　Drying process during the nighttime, when the temperature sensor sensed that the internal temperature of

27、 the drying room was too low, the control valve inlet of the collector was interrupted, hot air blew from the pipe in the water tank into the drying chamber. The drying process was similar to the daytime drying process.

28、</p><p>　　When the second day started, the control valve inlet of the collector opened, collector plates began daytime drying process. The process was recycled to achieve continuous drying operation. </p&

29、gt;<p>　　During poor weather conditions, the water in the water tank was heated by the electric, the control valve inlet of the collector was interrupted, hot air blew from the pipe in the water tank into the dryi

30、ng chamber. </p><p>　　The drying process was similar to the daytime drying process. The advantage of the solar drying equipment was continuous heating, low cost, simple structure, high drying and thermal eff

31、iciency.</p><p>　　(2) Air convection of the solar drying equipment included natural convection and forcedconvection. And the drying characteristics of the sample were studied in the solar drying equipment. D

32、rying time of the process of natural convection required to 14h to attain the drying requirement, while the process of forced convection drying time required 12h, far below the traditional the process of sun drying which

33、 required 50h. During drying process of the sample, the Deff value was 1.39 × 10-6m2/s unde</p><p>　　(3) Chemical quality and sensory characteristics of the plum samples were investigated under two dryi

34、ng methods of the solar equipment. The experiment results showed that with lower moisture content of the samples, the sugar content, acid content and the salt content of the sample increased at different layers of the dr

35、ying room.</p><p>　　For the color of the sample, the value of L* and the value of a increased caused by non-enzymatic browning. The peel and the pulp of the sample had the opposite trend during the drying pr

36、ocess for the value of b. The b value of peel decreased while the b value of pulp increased. All the experiment value was according to the factory product quality requirements. </p><p>　　Chemical quality

37、and sensory characteristics of the plum samples were investigated in different layers of the solar drying equipment. Results show that appropriate adjustments to the location of materials were recommended during natural

38、convection to improve the quality of the products. For the quality of products were relatively stable during forced convection drying process, it had no needs for adjusting the position to improve the quality of the samp

39、le.</p><p>　　(4) The research of solar drying equipment under different drying methods showed that solar drying device has obvious advantages compared to natural sun drying, greenhouse drying, oven drying. T

40、he drying time of solar drying device was shortened up to 76%, while the total efficiency of the solar drying equipment was up to 63.4%. </p><p>　　The drying process under solar drying equipment was environm

41、ental protection and energy conservation. The drying environment was with high temperature and low humidity. The product quality and drying efficiency was some kind of increasing while the costs decreased in varying degr

42、ees. The equipment could meet the drying requirement of varieties of agricultural products.</p><p>　　(5) Samples were dried to target water content under different drying methods, the natural sun drying took

43、 about 50h, while greenhouse drying and oven drying took about 30h and 12h respectively. Drying time of solar drying equipment under natural convection and forced convection needed 14h and 12h respectively. The moisture

44、content within 12h underforced convection drying, oven drying, natural convection drying, natural sun drying and greenhouse drying were reduced to 58.08%, 57.08%, 60.21%, 64.</p><p>　　Fully aware of the anal

45、ysis could be known that greenhouse drying, natural convection and forced convection drying were investigated by using the self-made solar drying equipment. The difference among solar drying equipment, traditional hot ai

46、r drying and natural sun drying were also investigated. The test results provided theoretical basis for practical application of the self-made solar drying equipment to the factory production.</p><p>　　The c

47、haracteristics of discontinuity and disperse of solar radiation give a great difficulty in solar energy applications. The absorption and storage of solar radiation has important effect on the utilization efficiency of so

48、lar energy. In heating buildings and greenhouses, the solar wall is a key part to incorporate the utilization of solar energy with the building, and also subject studied by researchers at home and abroad. So, it is very

49、important to study the solar wall. In this paper, actua</p><p>　　For simplification, one-dimensional mathematic model is used to describe the heat transfer and flow in the porous solar wall. The flow and hea

50、t transfer in the porous wall with the air as heat transfer medium are investigated primarily. To reach such conclusions, the porous wall can collect and store solar energy, and heat air; The air temperature will increas

51、e with a decrease in the inlet velocity; On the premise of demand for solar radiation collection, the air temperature will increase with a</p><p>　　Based on the thermal analysis, the structure of the porous

52、solar wall is improved and a new porous solar wall is designed to reduce convection and radiation heat exchanges between the porous wall and the ambient. The glass plate is located between the porous wall and the ambient

53、 to form a glass duct, which can reduce heat losses and collect hot air by using "greenhouse effective". Additionally, the fan is located in the duct near the inside surface of the porous wall. Under the action

54、 of the fan</p><p>　　A new greenhouse with heat-storage porous wall is designed, in which the north wall is a heat-storage porous wall. Equal diameter, uniform and semitransparent porous balls are used as th

55、e material of the porous solar wall, which can collect and store solar energy to heat the air in the greenhouse, and condition the thermal environment in the greenhouse. Their effect both can be exerted fully by combinin

56、g the greenhouse with the heat-storage porous wall, which causes the higher solar energy utili</p><p>　　Two kinds of new solar heating systems with a new porous heat storage wall are designed, which have dif

57、ferent ventilation patterns. Based on k-E turbulent model, Brinkman-Forchheimer Extended Darcy model and energy two-equation model for saturated porous medium, the coupled heat transfer and flow characteristics in the ne

58、w solar heating system are simulated, analyzed and compared. The results show that ventilation pattern has great effect on temperature field and flow field, which also has impor</p><p>　　Based on the mathema

59、tical model used to describe the structure filled with uniform and equal diameter porous balls, the structure characteristics of porous solar wall are investigated further. The results show that the flow resistance will

60、decrease with an increase in particle diameter and porosity. The results also provide parameters for an optimization of the porous wall.</p><p>　　The porous solar wall experiment system is also designed, whi

61、ch can be used to investigate such performance parameters as the flow resistance of the porous solar wall system, the absorptivity and volume convection heat transfer coefficient of the porous wall etc. But simulation of

62、 solar radiation is so difficult that the porous solar wall experiment system should be developed further to test the thermal performance of the porous wall accurately.</p><p>　　KEY WORDS： Solar drying， Forc