Abstract

The experience of operating powerful energy steam turbines has clearly shown that a significant share of losses with reduced steam consumption is accounted for by the steam distribution system, which is characterized by intensive throttling of steam entering the turbine’s flow section. Of the two main steam distribution systems—throttle and nozzle—nozzle steam distribution has an obvious advantage, where, unlike throttle, a reduction in steam flow through a turbine is achieved by throttling not only the entire steam stream but only part of it in a series of consecutively opening valves. To implement this method of steam distribution, it was necessary to introduce a special regulating stage into the turbine flow section, separated from the remaining stages by a regulating stage chamber (mixing chamber) designed to equalize uneven velocity fields at the entrance to the first unregulated stage, which are especially distinct with partial turbine loads. A detailed analysis of the advantages and disadvantages of the throttle and nozzle steam distribution is given and it is indicated that, taking into account all the additional consequences associated with the use of nozzle steam distribution, its advantage over the throttle becomes noticeable only when the turbine load is reduced by more than 25%. To eliminate the disadvantages inherent in the nozzle steam distribution, it is proposed to move the mixing chamber (chamber of the control stage) outside the turbine casing, thereby eliminating the control stage and greatly simplifying the supply of steam to the high-pressure cylinder of the steam turbine. In conclusion, a constructive solution for nozzle steam distribution with an external mixing chamber is proposed.

中文翻译：

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带远程混合室的喷嘴蒸汽分配

摘要

运转强大的节能型蒸汽涡轮机的经验清楚地表明，蒸汽分配系统可减少蒸汽消耗，这是损失的很大一部分，其特点是进入涡轮机流动部分的蒸汽经过大量节流。在两个主要的蒸汽分配系统（节气门和喷嘴）中，喷嘴蒸汽分配具有明显的优势，与节流阀不同，通过不仅使整个蒸汽流而且仅对一部分蒸汽进行节流来减少通过涡轮的蒸汽流量。系列连续打开的阀门。为了实施这种蒸汽分配方法，有必要在涡轮机的流动部分引入一个特殊的调节级，通过调节级室（混合室）与其余级分开，该级被设计为使第一级非调节级入口处的不均匀速度场相等，这在部分涡轮负载下尤其明显。对节气门和喷嘴蒸汽分配的优缺点进行了详细分析，结果表明，考虑到与使用喷嘴蒸汽分配有关的所有其他后果，只有在涡轮机中，其在节流方面的优势才变得明显。负载减少了25％以上。为了消除喷嘴蒸汽分配固有的缺点，建议将混合室（控制级室）移至涡轮机壳体外，从而省去了控制阶段，并大大简化了向蒸汽轮机高压缸的蒸汽供应。总而言之，提出了使用外部混合室的喷嘴蒸汽分配的建设性解决方案。