本文關(guān)鍵詞： 冷庫(kù) 雙蒸發(fā)器 熱氣融霜 蓄冷　出處：《天津商業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：冷庫(kù)運(yùn)行一段時(shí)間后,制冷系統(tǒng)中的蒸發(fā)器出現(xiàn)結(jié)霜現(xiàn)象,結(jié)霜嚴(yán)重時(shí)會(huì)造成蒸發(fā)器的蒸發(fā)能力降低,能耗大幅度增加等各種惡劣的影響,所以必須要求除霜。目前常用的除霜方式有電熱除霜和熱氣除霜,不管用何種除霜方法,總會(huì)有大部分熱量散到冷庫(kù)周圍環(huán)境,這不但使能量有所損失,而且還破壞了周圍的溫度場(chǎng)。為保證食物儲(chǔ)藏的品質(zhì),本課題著眼于降低冷庫(kù)溫度波動(dòng)的蓄冷裝置的研究。本課題從理論上分析了霜的結(jié)構(gòu),霜的物性參數(shù)和蒸發(fā)器性能參數(shù),然后重點(diǎn)對(duì)冷庫(kù)進(jìn)行理論分析計(jì)算,針對(duì)空庫(kù)狀態(tài)下連續(xù)融霜過程中庫(kù)溫波動(dòng)計(jì)算得到最大可能需要的蓄冷量;利用Fluent對(duì)帶蓄冷裝置的冷庫(kù)在連續(xù)融霜過程中的氣流場(chǎng)進(jìn)行模擬計(jì)算,然后分析結(jié)果,用實(shí)驗(yàn)值驗(yàn)證模擬值的可靠性;最后開始冷庫(kù)降溫實(shí)驗(yàn),將冷庫(kù)溫度場(chǎng)維持在-18±0.5℃半小時(shí)左右,使冷庫(kù)溫度場(chǎng)達(dá)到穩(wěn)定狀態(tài),當(dāng)冷庫(kù)達(dá)到除霜要求時(shí)開始除霜,分析研究冷庫(kù)有無蓄冷板時(shí)在制冷風(fēng)機(jī)有無霜層的工況下在0m,0.7m,1.4m,2m處的截面溫度,冷庫(kù)整體溫度,1號(hào)2號(hào)風(fēng)機(jī)中軸線位置處蓄冷板底部溫度和融霜能耗等。研究結(jié)果表明:除霜過程中,安裝蓄冷板的冷庫(kù)各截面溫度均低于空庫(kù)溫度;制冷風(fēng)機(jī)有霜狀態(tài)下,安裝蓄冷板整體庫(kù)溫波動(dòng)比空庫(kù)溫度波動(dòng)減小2.48℃,融霜能耗增加1.36%,可以忽略不計(jì)蓄冷板的安裝對(duì)融霜能耗的影響;制冷風(fēng)機(jī)無霜狀態(tài)下,安裝蓄冷板整體庫(kù)溫波動(dòng)比空庫(kù)溫度波動(dòng)減小2.92℃,融霜能耗增加1.81%,同樣可以忽略不計(jì)蓄冷板對(duì)融霜能耗的影響;制冷風(fēng)機(jī)中軸線位置處蓄冷板底部的溫度在遠(yuǎn)離風(fēng)機(jī)位置處越高,融霜風(fēng)機(jī)中軸線位置處蓄冷板底部的溫度在遠(yuǎn)離風(fēng)機(jī)位置處越低。通過實(shí)驗(yàn)對(duì)比得,冷庫(kù)頂部安裝蓄冷板能夠有效降低冷庫(kù)連續(xù)融霜過程中的冷庫(kù)溫度波動(dòng)。這樣雙蒸發(fā)器融霜過程中庫(kù)頂安裝的蓄冷裝置既減小了冷庫(kù)內(nèi)溫度波動(dòng),又保證了冷庫(kù)內(nèi)濕度的恒定。
[Abstract]:After the cold storage operation for a period of time, the evaporator in the refrigeration system appears frosting phenomenon, when frosting is serious, the evaporator evaporation ability will be reduced, the energy consumption will be greatly increased and other bad effects. So defrosting must be required. At present, the commonly used defrosting methods are electrothermal defrosting and hot gas defrosting. No matter what kind of defrosting method is used, most of the heat is always dispersed into the surrounding environment of the freezer, which not only results in a loss of energy, In order to ensure the quality of food storage, this project focuses on the research of the cold storage device to reduce the temperature fluctuation in the cold storage. The structure of the frost, the physical parameters of the frost and the performance parameters of the evaporator are analyzed theoretically. Then, the theoretical analysis and calculation of the cold storage are carried out, and the maximum amount of cold storage is obtained according to the fluctuation of the reservoir temperature in the process of continuous defrosting under the condition of empty storage. Fluent is used to simulate the airflow field of a cold storage tank in the process of continuous defrosting, then the results are analyzed, and the reliability of the simulated value is verified with the experimental value. Finally, the cold storage cooling experiment is started. If the temperature field of the cold storage is maintained at -18 鹵0.5 鈩，

本文編號(hào)：1494158