能源使用先期管理資訊平台

Losses during short cycles occur every time a boiler is switched off for a short period of time. The boiler cycle consists of a purge period, a post-purge, an idle period, a pre-purge and a return to firing. Part of the losses during the purge periods and idle period can be low in modern, well isolated boilers, but can increase rapidly in older boilers with inferior insulation.
Losses due to short term cycles for steam boilers can be magnified if the boilers can generate the required capacity in a very short period of time. This is the case if the installed capacity of the boiler is considerably larger than that generally needed. The steam demand for the process can change over time and should be reassessed periodically (see Section 2.2.2). Total steam demand may have been reduced through energy savings measures. Alternatively, boilers may have been installed with a view to a later expansion, which was never realised.
A first point for attention is the type of boiler in the design phase of the installation. Fire tube boilers have considerably large thermal inertia, and considerable water content. They are equipped to deal with continuous steam demand and to meet large peak loads. Steam generators or water tube boilers in contrast can also deliver steam in larger capacities. Their relatively lower water content makes water pipe boilers more suitable for installations with strongly varying loads.
Short cycling can be avoided by installing multiple boilers with a smaller capacity instead of one boiler with a large capacity. As a result, both flexibility and reliability are increased. An automated control of the generation efficiency and of the marginal costs for steam generation in each boiler can direct a boiler management system. Thus, additional steam demand is provided by the boiler with the lowest marginal cost.
Another option is possible where there is a standby boiler. In this case, the boiler can be kept to temperature by circulating water from the other boiler directly through the standby boiler. This minimises the flue-gas losses for standby. The standby boiler should be well insulated and with a correct air valve for the burner.
Energy savings can be obtained by boiler isolation or boiler replacement.

當鍋爐在短時間內開停車會造成能源的損失。鍋爐的運轉過程有吹掃期、後吹掃期、靜置期、預吹掃，而後回到點火加熱。先進且絕熱良好的鍋爐在吹掃期與靜置期的熱能損失較少，但老式又絕熱不良的鍋爐損失就會提高不少。
如果一座鍋爐能在短時間內產生所需要的蒸汽量，則短期運轉蒸汽鍋爐的損失會增大。同樣地，因為考慮未來產能的擴充而加大容量的鍋爐也可能有同樣情形，，但是可能從來不會實現。這現象說明了鍋爐的裝置容量有可能比實際需求的容量還大。製程所需的蒸氣量會隨時隨地變化，所以應該定期評估用量情形。蒸汽的總需求量可以透過各種節省能源的方法來減少。
首先要注意的是設施設計階段所採用的鍋爐型式。火管式鍋爐有頗大量熱慣性(譯註：加溫和降溫都要花長時間及需要許多用水)，以提供連續性蒸氣需求及大型尖峰負載時使用。蒸氣產生器或水管式鍋爐相對來說也可以提供較大量的蒸氣容量，相較之下，水管式鍋爐需要較低的水容積，比較適合用於負載變動很大的設施。
鍋爐短周期運轉是可以避免的。可以裝置多座鍋爐系統，其中利用一較小容量的鍋爐去取代一座大容量鍋爐，這樣設計在彈性和可靠度都可以提升。
自動控制每一座鍋爐產出效率和蒸氣發生的邊際成本資訊，將之導引至鍋爐管理系統，這樣額外的蒸氣需求就可以由最低邊際成本的鍋爐供應。
另外一個可行的方式是設置一備用鍋爐。此鍋爐可以從其他鍋爐將水循環到這備用鍋爐，以維持其一定的溫度，如此可減少燃燒此座鍋爐時的煙氣熱損失。這座備用鍋爐必須要良好的保溫和裝設正確的燃燒器進氣控制閥門。