【正文】
高壓氣缸吸氣溫度(圖1中BC),是降低排氣溫度的有效方法。如果壓縮機回氣溫度為20℃,理論排氣溫度將高達193℃(排氣管上測得的溫度約為160℃)。九十年代中后期,環(huán)保制冷劑R404A以及POE潤滑油等技術(shù)被認可后,他們紛紛放棄了R22雙級壓縮機,再次采用了單級壓縮機,并開始使用環(huán)保制冷劑R404A。實際情況要復雜一些。 2stage pressor。單級壓縮機與雙級壓縮機在超市應用中的比較摘要:單級壓縮機與雙級壓縮機的結(jié)構(gòu)不同,制冷溫度覆蓋的范圍也不同,使用場合應該有所區(qū)別。關(guān)鍵詞:單級壓縮機;雙級壓縮機;超市冷凍冷藏Comparison of Singlestage Compressors Versus 2stage Compressors In Supermarket ApplicationJet Han Joe Healy☆ Emerson Climate Technologies, Hong KongAbstract: Singlestage and 2stage pressors are very different in structure, and the ranges of temperature they cover are not identical, applications of these two pressors should therefore be discriminated. Although both pressors can be used for supermarket food preservation at evaporating temperature of –32℃~38℃, the results are different. Analysis of the performances, costs and reliabilities of both pressors in applications to supermarket is carried out in this paper.Key words: Singlestage pressor。有人就建議使用單機雙級壓縮機(以下簡稱雙級壓縮機),并認為雙級壓縮機制冷量大,效率高。由于R22排氣溫度高,為了保證足夠的蒸發(fā)溫度(-32~-38℃),當時只能選擇雙級壓縮機。2. 排氣溫度 對于普通回氣冷卻型單級壓縮機,如果系統(tǒng)工質(zhì)為R22,℃, 蒸發(fā)溫度為40℃時,壓縮比為21。phG G’F F’E E’ D D’A A’ C B 圖1 單/雙級制冷系統(tǒng)壓焓圖 雙級壓縮機的氣體壓縮是分兩步(圖1中AB,CD)在兩個氣缸(低壓氣缸及與高壓氣缸)中