Where heat is applied to a process via a heat exchanger, the steam surrenders energy as latent heat as it condenses to hot water. This water is lost, or ( usually) collected and returned to the boiler. Re-using condensate has four objectives:
●re-using the energy contained in the hot condensate
●saving the cost of the (raw) top-up water
●saving the cost of boiler water treatment (the condensate has to be treated)
●saving the cost of waste water discharge (where applicable).
Condensate is collected at atmospheric and negative pressures. The condensate may originate from steam in appliances at a much higher pressure.

蒸汽以熱交換器將其潛熱釋出提供製程使用後，凝結成為熱水，此熱水就可以不再使用了，但一般都會將之收集起來回到鍋爐再利用。再利用凝結水有下列目的：
●熱凝結水中的熱焓再利用
●節省補充水(原水)的水費
●節省鍋爐水處理的成本(凝結水不必再處理)
●節省廢水排放的費用
蒸汽在設備中以高壓狀態做功後凝結成水，被收集時已成常壓或負壓狀態。

No data submitted.

無資料。

The technique is not applicable in cases where the recovered condensate is polluted or if the condensate is not recoverable because the steam has been injected into a process.
With respect to new designs, a good practice is to segregate the condensates into potentially polluted and clean condensate streams. Clean condensates are those coming from sources which, in principle, will never be polluted ( for instance, coming from reboilers where steam pressure is higher than process pressure, so that in the case of leaking tubes, steam goes into the process rather than process components into the steam side). Potentially polluted condensates are condensates which could be polluted in the case of an incident (e.g. tube rupture on reboilers where process-side pressure is higher than steam-side pressure). Clean condensates can be recovered without further precautions. Potentially polluted condensates can be recovered except in the case of pollution (e.g. leak from a reboiler) which is detected by online monitoring, e.g. TOC meter.

這項技術不能用在回收凝結水受到汙染或蒸汽直接噴入製程後已無可能成凝結水回收的情況。
較新的蒸汽系統設計會將受汙染的和乾淨的凝結水分開。乾淨的管路來自絕不會受到汙染的來源，(例如從再沸器來的，其中蒸汽壓力會比製程壓力大，如果管子有洩漏，蒸汽就進入製程而製程端不會進入蒸汽端)。凝結水受到汙染的原因可能因為事故發生(例如再沸器蒸汽管破裂致製程端的壓力大於蒸汽端)。清潔的凝結水回收後可以不需再做預防處理。有被污染可能的凝結水仍然可以回收，除非汙染情形已被線上偵測儀器偵測到已經汙染了(如被線上總有機碳分析儀TOC偵測到 )。

The recovery of condensate has significant benefits and should be considered in all applicable cases ( see Applicability, above), except where the a mount of condensate is low ( e.g. where steam is added into the process).

凝結水的回收效益顯著，應該在所有的可應用的案件上使用，除非是蒸汽大量被注入到生產製程當中，可凝結成水的量較少。

Energy Efficiency (2009) 3.2.13