中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2012年
17期
25-30
,共6页
戈志华%杨佳霖%何坚忍%贺茂石
戈誌華%楊佳霖%何堅忍%賀茂石
과지화%양가림%하견인%하무석
大型纯凝机组%供热%背压机%变工况%节能
大型純凝機組%供熱%揹壓機%變工況%節能
대형순응궤조%공열%배압궤%변공황%절능
large scale pure condensing unit%heating%backpressure turbine%off-design%energy-saving
大型纯凝汽轮机供热改造过程中，由于中压缸级数相对于设计的供热机组少，导致中低压缸联通管打孔抽汽压力远远高于所需求的供热压力，造成可用能的节流损失。该文针对此问题提出了解决措施，即增加背压机，将较高压力的抽汽先做功发电后再进行供热。分别针对单机型和双机型大型纯凝汽轮机的供热改造建立了理论分析模型，结合实际300Mw机组的案例分析发现，采用增加背压机做功的模式，对单机型改造，可以在不影响供热效果的前提下，回收供热抽汽的动力，同时由于不与另外机组耦合，设备结构简单，运行控制简便；对双机型改造，设备连接虽相对复杂，但采用热网加热器的串联模式，能量的梯级利用更加合理，保证供热的条件下，回收了更多的供热抽汽动力。结果表明，新型的供热改造模式可以收到较好的综合经济效益。
大型純凝汽輪機供熱改造過程中，由于中壓缸級數相對于設計的供熱機組少，導緻中低壓缸聯通管打孔抽汽壓力遠遠高于所需求的供熱壓力，造成可用能的節流損失。該文針對此問題提齣瞭解決措施，即增加揹壓機，將較高壓力的抽汽先做功髮電後再進行供熱。分彆針對單機型和雙機型大型純凝汽輪機的供熱改造建立瞭理論分析模型，結閤實際300Mw機組的案例分析髮現，採用增加揹壓機做功的模式，對單機型改造，可以在不影響供熱效果的前提下，迴收供熱抽汽的動力，同時由于不與另外機組耦閤，設備結構簡單，運行控製簡便；對雙機型改造，設備連接雖相對複雜，但採用熱網加熱器的串聯模式，能量的梯級利用更加閤理，保證供熱的條件下，迴收瞭更多的供熱抽汽動力。結果錶明，新型的供熱改造模式可以收到較好的綜閤經濟效益。
대형순응기륜궤공열개조과정중，유우중압항급수상대우설계적공열궤조소，도치중저압항련통관타공추기압력원원고우소수구적공열압력，조성가용능적절류손실。해문침대차문제제출료해결조시，즉증가배압궤，장교고압력적추기선주공발전후재진행공열。분별침대단궤형화쌍궤형대형순응기륜궤적공열개조건립료이론분석모형，결합실제300Mw궤조적안례분석발현，채용증가배압궤주공적모식，대단궤형개조，가이재불영향공열효과적전제하，회수공열추기적동력，동시유우불여령외궤조우합，설비결구간단，운행공제간편；대쌍궤형개조，설비련접수상대복잡，단채용열망가열기적천련모식，능량적제급이용경가합리，보증공열적조건하，회수료경다적공열추기동력。결과표명，신형적공열개조모식가이수도교호적종합경제효익。
During the process of heating retrofitting, the pressure of steam extracted from the communicating pipe between intermediate pressure（IP） and low pressure（LP） cylinders is much higher than required heating pressure, because the IP cylinder of pure condensing turbine has fewer stages than cogeneration turbine. Heating with such high pressure steam leads to the waste of energy grade. To solve this problem, this paper proposed a measure that using a back pressure turbine to bring high pressure of extracted steam down and generate power, after that the steam with reasonable pressure transferred heat with water in heat-supply network. Viewing of single and double retrofitted unit, the analytical models were set up respectively. Based on theoretical calculation of 300MW retrofitted unit, it can be found that much power is recovered with no impact on heating. The improvement proposal for single retrofitted unit has the advantage of simple structure and convenient maintain and operation. While to the improvement proposal for double retrofitted units we can recover more power as a result of series thermal-system heater and the effect of cascade utilization of energy is more apparent, though the structure of this system is more complex. In conclusion, the new retrofitted mode to pure condensing unit not only has no impact on heating, but also can gain more economic returns.
