編者按：日(ri)前，國際(ji)電力(li)行業知名(ming)刊物《Power》刊登(deng)題為(wei)“模塊化發電(dian)廠(chang)正在(zai)提(ti)高肯尼亞地熱效率”的(de)文章，向全球介紹我集團首(shou)創的(de)地熱井口電(dian)站技術及其成(cheng)(cheng)就。這是繼新華社、《人民日報》等(deng)中國(guo)央媒介紹開山在(zai)肯尼亞取得的(de)成(cheng)(cheng)就之后，又一個國(guo)際級(ji)媒體的(de)推介。
《Power Magazine》在(zai)(zai)全球(qiu)電力(li)(li)行(xing)業(ye)(ye)具(ju)有顯著的(de)(de)(de)(de)(de)(de)(de)(de)影響力(li)(li)。作為(wei)全球(qiu)最古老(lao)的(de)(de)(de)(de)(de)(de)(de)(de)能源(yuan)行(xing)業(ye)(ye)期刊(kan)(kan)之(zhi)一(yi)，自(zi)(zi)1882年創刊(kan)(kan)以來(lai)(lai)，已成為(wei)電力(li)(li)行(xing)業(ye)(ye)內(nei)的(de)(de)(de)(de)(de)(de)(de)(de)重(zhong)要信(xin)(xin)息來(lai)(lai)源(yuan)和(he)(he)(he)行(xing)業(ye)(ye)標(biao)準。其(qi)影響力(li)(li)既源(yuan)于權(quan)(quan)威性和(he)(he)(he)歷史性，還因為(wei)其(qi)擁(yong)有廣泛的(de)(de)(de)(de)(de)(de)(de)(de)受眾(zhong)群體，讀者(zhe)涵蓋(gai)了全球(qiu)電力(li)(li)行(xing)業(ye)(ye)專(zhuan)業(ye)(ye)人士，包括電力(li)(li)工程師、運營經(jing)理、技(ji)(ji)術(shu)專(zhuan)家、決(jue)策者(zhe)和(he)(he)(he)企業(ye)(ye)高管，它通過提供深入的(de)(de)(de)(de)(de)(de)(de)(de)技(ji)(ji)術(shu)分析、案例(li)研(yan)究和(he)(he)(he)行(xing)業(ye)(ye)新聞，幫助專(zhuan)業(ye)(ye)人士做出更好的(de)(de)(de)(de)(de)(de)(de)(de)決(jue)策和(he)(he)(he)理解行(xing)業(ye)(ye)動態。《Power Magazine》在(zai)(zai)全球(qiu)電力(li)(li)行(xing)業(ye)(ye)扮演重(zhong)要的(de)(de)(de)(de)(de)(de)(de)(de)角色，既是信(xin)(xin)息傳(chuan)播的(de)(de)(de)(de)(de)(de)(de)(de)重(zhong)要渠(qu)道，也(ye)是行(xing)業(ye)(ye)趨勢(shi)和(he)(he)(he)技(ji)(ji)術(shu)發展的(de)(de)(de)(de)(de)(de)(de)(de)風向標(biao)，該刊(kan)(kan)物宣介開山(shan)地(di)熱(re)井口模(mo)塊(kuai)電站技(ji)(ji)術(shu)標(biao)志(zhi)著我集(ji)團(tuan)擁(yong)有自(zi)(zi)主(zhu)知(zhi)識產權(quan)(quan)的(de)(de)(de)(de)(de)(de)(de)(de)核(he)心技(ji)(ji)術(shu)得(de)到業(ye)(ye)內(nei)主(zhu)流媒體的(de)(de)(de)(de)(de)(de)(de)(de)認同，也(ye)料(liao)將極(ji)大地(di)推動開山(shan)技(ji)(ji)術(shu)在(zai)(zai)全球(qiu)的(de)(de)(de)(de)(de)(de)(de)(de)應用。
下(xia)面(mian)是(shi)本(ben)編輯(ji)部轉(zhuan)發的新聞鏈接和轉(zhuan)載(zai)文(wen)章的中英文(wen)對(dui)照文(wen)本(ben)，以饗讀者。
原文(wen)鏈接：//www.powermag.com/a-modular-power-plant-is-steaming-up-kenyas-geothermal-efficiency/
A Modular Power Plant Is Steaming Up Kenya's Geothermal Efficiency
Sosian Menegai during the commissioning phase. Courtesy: Kaishan Group
Sosian Menengai Geothermal Power, Kenya’s newest geothermal power plant, is powered by modular technology that maximizes efficiency, reduces costs, and enhances scalability.
Kenya’s scenic Rift Valley region is a literal hotbed of geothermal potential. Part of the vast East African Rift Valley System (EARS), a 6,400-kilometer (km) tectonic divergence that is cleaving the African continent into two plates, Kenya’s Rift Valley forms a vertical corridor of intensive faulting and volcanic activity, hot springs, fumaroles, and sulfur-oozing fissures. But while the country began geothermal exploration for power development in the 1950s, most of its investments have been focused on the Olkaria region situated within Hell’s Gate National Park near the flamingo-flecked Lake Naivasha in Nakuru County. Five of six geothermal power stations in Olkaria are owned by KenGen (with a combined capacity of 799 MW), while Nevada-based Ormat Technologies owns a 150-MW plant. Olkaria plants in 2023 provided nearly 45% of Kenya’s total generation, a sizeable contribution to the East African powerhouse’s meager 3.3-GW installed capacity.
In 2008, the Geothermal Development Co. (GDC), a state-owned special-purpose vehicle tasked with accelerating the nation’s geothermal resource development, expanded its focus to the Menengai region just north of Olkaria, at the site of a massive shield volcano with one of the biggest calderas in the world. While GDC says the Menengai complex harbors a potential of 1,600 MW, its long-term goal is to develop 465 MW of geothermal steam equivalent.
In 2013, it took the first step to competitively award the first three initial 35-MW power projects at the complex to three independent power producers (IPPs): Orpower 22 (a former subsidiary of New York firm Symbion now owned by China’s Kaishan Group), South African-based Quantum Power East Africa (now majority owned by UK firm Globeleq), and Nairobi-headquartered Sosian Energy. In August 2023, the first of these projects—Menengai III, now formally known as the Sosian Menengai Geothermal Power—wrapped up a 16-month construction timeframe and began delivering first power to the grid.
Map showing location of geothermal area along the Kenyan Rift Valley. Courtesy: KenGen
A Technology Breakthrough
Sosian’s condensed timeframe is especially stunning given that traditional geothermal development can exceed seven years. This is owing in part to a complex process that involves drilling and testing multiple wells, selecting a centralized power plant location, ordering steam turbines, and constructing extensive steam collection and reinjection systems. The traditional approach is also ridden with risks, including significant delays and inefficiencies, such as energy losses from steam pressure drops, thermal losses over long distances, and the underutilization of wells with varying pressures.
Sosian, to some measure, had the benefit of the GDC’s public-private partnership model for developing Menengai, under which the GDC assumes upfront risks of geothermal development. The state company has also notably set out to develop the field in five phases, starting with a 105-MW “steam sales” model, where it supplies steam from drilled wells to the power plants via a 25-km steam gathering and piping system. As of 2023, GDC had drilled 53 wells with a potential of 169 MW.
However, the power plant’s success can also be attributed to a distinctive new geothermal development process introduced by China’s Kaishan Group. Dr. Tang Yan, general manager of Kaishan Group, recalled realizing the need for a dramatic shift at a 2015 geothermal conference in Melbourne, Australia, where experts discussed the pitfalls of conventional methods. “I said, ‘Why don’t you put a power plant on the wellhead and do it phase by phase?’ ” he recounted.
Overcoming Traditional Challenges
While the approach proposed to support incremental power production from the start while providing revenue to support future project expansion, Yan learned no technology to support the approach was commercially available. Kaishan, which had then already begun its transition from a giant Shanghai-headquartered air compressor maker to a diversified global company, jumped into action to leverage its 2012-developed Organic Rankine Cycle (ORC) expander and screw steam expander technologies.
The technologies—originally developed for waste heat recovery from refineries and steel mills—allowed Kaishan to optimize geothermal power generation by maximizing energy output from varying well conditions, reducing inefficiencies, and enabling the development of four types of decentralized, modular power plants that are quicker to deploy and more adaptable to different geothermal fields, Yan told POWER. “These modular power plants include the steam screw expander modular power plants, the steam ORC modular power plants, the brine ORC modular power plants, and the steam and brine dual resource modular power plants,” he explained.
Steam screw expanders are specifically designed to handle wet or saturated steam, which is common in geothermal wells, effectively extracting energy from a wider range of well conditions, including wells with high non-condensable gas (NCG) content that may not be suitable for traditional turbines. ORC systems, meanwhile, are adept at converting lower-temperature steam and brine—byproducts that would otherwise go to waste—into additional electricity, Yan said.
In addition, Kaishan’s modular plants can be used to form hybrid cycles or thermal systems to meet any production well conditions, maximize their power output, and eliminate low-head pressure (WHP) wasted wells or idling wells. Because the technologies can be adapted to specific geothermal resource conditions at different project sites, they can be tailored to provide stellar efficiency, he said. “We can improve the well thermal efficiency of, for example, medium enthalpy wells, to up to 18% and 19%,” he said. That compares to only 8% to 12% for traditional centralized power plants that only use single-flash steam, he noted.
he 35-MWe Sosian Menengai Geothermal Power plant was commissioned in August 2023. The plant uses two Kaishan geothermal steam counterpressure screw expanders, which discharge their exhausts into three Organic Rankine Cycle units. Courtesy: Kaishan Group
A Competitive Edge for New Geothermal Power
Kaishan quickly expanded the niche technology into a lucrative business. Since it put online the first of four phases of the 240-MW Sorik Marapi Geothermal Project in Indonesia in 2018, it has built the 10-MW Sokoria Geothermal, also in Indonesia, alongside projects in Turkey, the U.S., and Hungary. At Sosian, Kaishan’s first project in Kenya, the company served as the engineering, procurement, and construction (EPC) contractor.
According to Yan, Kaishan’s cost-effective price point proved a crucial selection advantage. Kaishan’s EPC contract is valued at $65 million, compared to a $108 million EPC contract recently awarded for Menengai II, one of the region’s three equally sized IPP projects. The price difference is rooted in the technology selection, Yan explained. While Sosian’s 35-MW project was designed as a centralized power plant, it is powered by two steam screw expanders and three wet steam ORC modular power plants.
However, GDC’s steam contains 3.3% NCG—which represents a “huge percentage,” he said. If Sosian used traditional steam turbines, they would need to expand steam at 6 bar absolute and then consume more then 30 tons of steam per hour to remove NCG using steam injectors and vacuum pumps. Instead, Sosian employs steam screw expanders and a bottom cycle to handle the saturated steam discharge, reducing the steam to atmospheric levels throughout the entire process while eliminating the parasitic power typically consumed by vacuum systems.
“The overall efficiency compared to a traditional steam turbine is a huge game changer for this site,” Yan said. “The project only needed a guarantee of 33.25 MW, and the target was 35 MW, but we’re actually generating 37 MW.” At the same time, the project doesn’t need to purchase the extra 10% of steam for a steam injector, putting less of a burden on the GDC, he said.
A Solution for Idled Wells
The modularity of the system also proved beneficial to speed up construction and, crucially, to overcome supply chain and project management challenges posed by the COVID pandemic, Yan said. Kaishan typically assembles the modules and conducts component testing in a factory setting over six to nine months, he said. “And then, when we ship to the site, usually it takes a very short time to put them together, and you don’t need to do any welding on the power modules,” he added. “That’s sometimes where quality control can be a challenge,” he noted.
The success of the Sosian Menegai project has so far sparked significant interest in Kenya’s geothermal industry, Yan said. A key reason is that Kenya has a lot of wells, and an estimated 25% to 30% of those wells may not be supported by a steam collection system, which is needed by centralized steam turbines. “They call them idled wells or wasted wells, and they sit there and do nothing,” even if it was costly to drill them, he said. “But our technology doesn’t have that limitation because we can use any good pressure, whether they can produce brine or steam.”
—Sonal Patel is a POWER senior editor (@sonalcpatel, @POWERmagazine).
中文翻譯稿
模塊化發電廠正在(zai)提高肯尼亞地熱效率
調試(shi)階段的 Sosian Menegai。圖片(pian)來源：開山集團(tuan)
肯尼亞最新(xin)的地熱發電廠(chang) Sosian Menengai 地熱發(fa)電廠(chang)采(cai)用模塊化技術，可最大限(xian)度提高(gao)效率(lv)、降低(di)成本(ben)并增強可擴展性。
肯尼亞(ya)(ya)風景秀麗的裂谷(gu)地區是(shi)(shi)地熱(re)資源的寶庫(ku)。肯尼亞(ya)(ya)裂谷(gu)是(shi)(shi)廣(guang)闊的東非(fei)大(da)裂谷系(xi)統(tong) (EARS) 的(de)(de)(de)一(yi)部(bu)(bu)(bu)分(fen)，東(dong)非大(da)裂谷(gu)系(xi)統(tong)是一(yi)個長(chang)達(da) 6,400 公(gong)(gong)里(li)(li)的(de)(de)(de)地(di)質構造分(fen)叉，將非洲大(da)陸一(yi)分(fen)為二。肯尼(ni)亞裂谷(gu)形成了(le)(le)一(yi)個垂直(zhi)走廊，其中(zhong)(zhong)有(you)密集的(de)(de)(de)斷層和火山活(huo)動、溫泉、噴氣(qi)孔和硫磺滲出(chu)的(de)(de)(de)裂縫。盡管肯尼(ni)亞在(zai) 20 世紀 50 年代(dai)就開始進行地(di)熱勘(kan)探(tan)以開發電(dian)力，但(dan)其大(da)部(bu)(bu)(bu)分(fen)投資都(dou)集中(zhong)(zhong)在(zai)位于(yu)地(di)獄(yu)之門國(guo)家公(gong)(gong)園(yuan)內的(de)(de)(de)奧(ao)爾卡里(li)(li)亞地(di)區，該公(gong)(gong)園(yuan)靠(kao)近納庫魯(lu)縣火烈鳥點(dian)綴(zhui)的(de)(de)(de)納瓦沙(sha)湖。奧(ao)爾卡里(li)(li)亞的(de)(de)(de)六座(zuo)地(di)熱發電(dian)站(zhan)中(zhong)(zhong)有(you)五座(zuo)歸 KenGen 所(suo)有(you)（總(zong)容量(liang)為 799 兆瓦），而(er)總(zong)部(bu)(bu)(bu)位于(yu)內華達(da)州(zhou)的(de)(de)(de) Ormat Technologies擁有(you)一(yi)座(zuo) 150 兆瓦的(de)(de)(de)發電(dian)站(zhan)。到 2023 年，奧(ao)爾卡里(li)(li)亞 (Olkaria) 電(dian)廠將提供(gong)肯尼(ni)亞近 45% 的(de)(de)(de)總(zong)發電(dian)量(liang)，為這個東(dong)非強國(guo)僅有(you)的(de)(de)(de) 3.3 吉瓦的(de)(de)(de)裝機容量(liang)做出(chu)了(le)(le)巨大(da)貢(gong)獻。
2008 年，地(di)(di)(di)熱(re)(re)開發(fa)公司(si) (GDC) 將重點擴(kuo)大到奧爾卡(ka)里(li)亞以(yi)北的(de)(de)(de)梅嫩蓋地(di)(di)(di)區，該(gai)地(di)(di)(di)區是(shi)(shi)一座巨大的(de)(de)(de)盾形火山，擁有(you)世界上最大的(de)(de)(de)火山口之一。地(di)(di)(di)熱(re)(re)開發(fa)公司(si)是(shi)(shi)一家國有(you)特殊目的(de)(de)(de)公司(si)，其(qi)任務是(shi)(shi)加速(su)該(gai)國的(de)(de)(de)地(di)(di)(di)熱(re)(re)資源開發(fa)。GDC 表示，梅嫩蓋綜合體蘊(yun)藏著 1,600 兆瓦(wa)的(de)(de)(de)地(di)(di)(di)熱(re)(re)潛力，但其(qi)長期目標是(shi)(shi)開發(fa) 465 兆瓦(wa)的(de)(de)(de)地(di)(di)(di)熱(re)(re)蒸汽當量。
2013 年，該(gai)集團邁出了第(di)一步(bu)，通過競爭方(fang)式將該(gai)綜合體中的前三個 35 兆瓦發電項目(mu)授予(yu)三家獨立電力供(gong)應商 (IPP)：Orpower 22（前身為(wei)紐約 Symbion 公(gong)司的子(zi)公(gong)司，現(xian)(xian)歸中國開山(shan)集(ji)團所(suo)有）、總(zong)部位(wei)于(yu)南(nan)非的 Quantum Power East Africa（現(xian)(xian)由英國公(gong)司 Globeleq 控股）和總(zong)部位(wei)于(yu)內羅畢(bi)的 Sosian Energy。2023 年 8 月(yue)，這些項(xiang)目(mu)中的第(di)一個(ge)項(xiang)目(mu)——Menengai III（現(xian)(xian)正式(shi)稱為(wei) Sosian Menengai 地熱發電項(xiang)目(mu)）結(jie)束了(le)為(wei)期(qi) 16 個(ge)月(yue)的建設(she)工期(qi)，并開始向電網輸(shu)送第(di)一批電力(li)。
地圖顯示了(le)肯(ken)尼亞(ya)裂谷沿線地熱區的位置。圖片(pian)來源：KenGen
技術突(tu)破
鑒于傳統(tong)地(di)熱(re)開(kai)發可(ke)能要耗時(shi)超過七年，Sosian 的(de)(de)縮短工期尤其令人震驚。這(zhe)在一定程度(du)上歸因于一個(ge)復雜的(de)(de)過程，包括鉆(zhan)探(tan)和測試多個(ge)井、選擇集(ji)中(zhong)發電廠位(wei)置、訂購蒸(zheng)汽渦輪(lun)機(ji)以及建造(zao)廣泛的(de)(de)蒸(zheng)汽收集(ji)和再(zai)注入系統(tong)。傳統(tong)方法也充滿風(feng)險，包括嚴重的(de)(de)延誤(wu)和效(xiao)率(lv)低(di)下，例如蒸(zheng)汽壓力下降造(zao)成的(de)(de)能量損失、長距離(li)熱(re)損失以及壓力變化(hua)的(de)(de)井的(de)(de)利(li)用不足(zu)。
在某種程度上，Sosian 受益于 GDC 開(kai)發(fa) Menengai 的(de)公(gong)私合作模式(shi)，根據(ju)該(gai)模式(shi)，GDC 承擔地(di)熱(re)開(kai)發(fa)的(de)前期風險。值(zhi)得注意(yi)的(de)是，這(zhe)家(jia)國(guo)有(you)公(gong)司還計劃(hua)分五個(ge)階(jie)段開(kai)發(fa)該(gai)地(di)熱(re)田(tian)，首先采用(yong) 105 兆瓦的(de)“蒸汽(qi)銷售”模式(shi)，通(tong)過 25 公(gong)里長(chang)的(de)蒸汽(qi)收集(ji)和管道系統將(jiang)鉆(zhan)井(jing)中的(de)蒸汽(qi)供應給發(fa)電(dian)廠。截(jie)至 2023 年，GDC 已(yi)鉆(zhan)探了 53 口井(jing)，潛力為(wei) 169 兆瓦。
然而，該發電廠(chang)的成功也歸功于中國開山集團推出的獨特的新型地(di)熱開發工藝。開山集團總經理湯炎博士(shi)回憶(yi)說，他(ta)在(zai) 2015 年澳大(da)利亞墨爾本(ben)舉行的地(di)熱會議上意(yi)識(shi)到需要進(jin)行重大(da)轉變(bian)，當時專家們討(tao)論了傳(chuan)統方法的缺陷。“我說，‘你為什么(me)不(bu)在(zai)井口(kou)建一個發電廠(chang)，分階段進(jin)行呢？’”他(ta)回憶(yi)道(dao)。
克服傳統(tong)挑戰
雖然該方法從一開(kai)始(shi)就(jiu)提出支持(chi)增量發(fa)電，同時提供收入以支持(chi)未(wei)來的(de)(de)(de)項目(mu)擴展，但湯炎博士了(le)解到(dao)，沒(mei)有支持(chi)該方法的(de)(de)(de)技術可供商業使(shi)用(yong)。開(kai)山當(dang)時已經開(kai)始(shi)從一家(jia)總部位于上海的(de)(de)(de)大型(xing)空(kong)氣壓縮機(ji)制造商轉型(xing)為一家(jia)多元化的(de)(de)(de)全球性公司，并立即采取行動(dong)，利用(yong)其 2012 年開(kai)發(fa)的(de)(de)(de)有機(ji)朗肯循(xun)環 (ORC) 膨脹機(ji)和(he)螺桿(gan)蒸汽膨脹機技(ji)術。
湯炎博士(shi)告訴《POWER》雜志，這(zhe)些技(ji)術(shu)最初是為回收(shou)煉油廠(chang)和(he)鋼廠(chang)的廢(fei)熱(re)(re)(re)而開(kai)發(fa)的，它使開(kai)山公司能夠通過最大限度(du)地提高(gao)不同井況(kuang)下的能量(liang)輸出、減少低(di)效率，以及開(kai)發(fa)四種類(lei)型(xing)的分散(san)式模塊化(hua)發(fa)電(dian)(dian)廠(chang)來優化(hua)地熱(re)(re)(re)發(fa)電(dian)(dian)，這(zhe)些發(fa)電(dian)(dian)廠(chang)部署速度(du)更快，更能適應不同的地熱(re)(re)(re)田。 “這些模(mo)塊化(hua)(hua)(hua)發(fa)電廠(chang)(chang)包括蒸汽螺桿(gan)膨脹機模(mo)塊化(hua)(hua)(hua)發(fa)電廠(chang)(chang)、蒸汽 ORC 模(mo)塊化(hua)(hua)(hua)發(fa)電廠(chang)(chang)、鹽水(shui) ORC 模(mo)塊化(hua)(hua)(hua)發(fa)電廠(chang)(chang)以及蒸汽和鹽水(shui)雙(shuang)資源模(mo)塊化(hua)(hua)(hua)發(fa)電廠(chang)(chang)，”他解釋說(shuo)。
蒸(zheng)(zheng)汽螺桿(gan)膨脹機專(zhuan)門(men)設計用于處理地熱(re)井(jing)中常見的(de)濕蒸(zheng)(zheng)汽或飽和蒸(zheng)(zheng)汽，可(ke)有(you)效從各種井(jing)況中提(ti)取能量(liang)，包括可(ke)能不適合傳統渦(wo)輪機的(de)不凝性氣體 (NCG)含量(liang)高的(de)井(jing)。與此同時(shi)，ORC 系統擅長將低溫蒸(zheng)(zheng)汽和鹽水（否則這些(xie)副產品(pin)將被浪費）轉化為額(e)外的(de)電能，湯炎博士說。
此外，開山的模塊(kuai)化電廠可(ke)(ke)用于形成混合循(xun)環或熱(re)力系(xi)統(tong)，以(yi)滿足任何生產井條(tiao)件，最(zui)大(da)限度(du)地(di)提高其發電量(liang)，并(bing)消除低壓(ya) (WHP) 浪費井或閑(xian)置井。他說，由于這些技術可(ke)(ke)以(yi)適應不同項目地(di)點的特定地(di)熱(re)資源條(tiao)件，因此可(ke)(ke)以(yi)量(liang)身(shen)定制以(yi)提供(gong)卓越的效(xiao)率。他說：“我們可(ke)(ke)以(yi)將(jiang)中焓井的熱(re)效(xiao)率提高到 18% 和(he) 19%。”他指出，相(xiang)比之下，僅使用單次閃(shan)蒸蒸汽的傳統(tong)集(ji)中式發電廠的熱(re)效(xiao)率僅為 8% 至 12%。
35 MWe 的(de) Sosian Menengai 地(di)(di)熱發電廠于(yu) 2023 年 8 月(yue)投入使用(yong)。該電廠使用(yong)兩臺開山(shan)地(di)(di)熱蒸(zheng)汽反壓(ya)螺桿膨脹機(ji)，將廢(fei)氣(qi)排放到三(san)個有機(ji)朗肯循(xun)環(huan)裝置(zhi)中。圖片來源(yuan)：開山(shan)集團
新地熱發電的競(jing)爭優勢
開(kai)山迅速將這(zhe)項(xiang)(xiang)小眾技術(shu)拓展為一項(xiang)(xiang)利潤豐厚的業務。自(zi)2018 年在印度尼西亞(ya)投產 240 兆瓦(wa) Sorik Marapi 地熱項(xiang)(xiang)目四期(qi)工程(cheng)中的第一期(qi)以來，該公司已在印度尼西亞(ya)建造了(le) 10 兆瓦(wa)的 Sokoria 地熱項(xiang)(xiang)目，此外還在土(tu)耳其(qi)、美國和匈牙利開(kai)展了(le)項(xiang)(xiang)目。Sosian是開山在肯尼亞的第一個地熱項(xiang)目，公司(si)擔任工程、采購和施(shi)工 (EPC) 承包商(shang)。
湯炎博(bo)士表示(shi)，開(kai)山電廠(chang)(chang)具有(you)成本(ben)效益(yi)的(de)價(jia)(jia)格點是其(qi)關鍵的(de)選擇優勢。開(kai)山電廠(chang)(chang)的(de) EPC 合(he)同價(jia)(jia)值(zhi) 6500 萬美(mei)元，而該(gai)地區三個同等規模的(de) IPP 項目(mu)之一(yi) Menengai II 最近(jin)獲(huo)得(de)的(de) EPC 合(he)同價(jia)(jia)值(zhi) 1.08 億(yi)美(mei)元。湯炎博(bo)士解釋說，價(jia)(jia)格差異的(de)根源在于技術選擇。雖然 Sosian 的(de) 35 兆瓦項目(mu)設計為集中式發電廠(chang)(chang)，但它由(you)兩個蒸汽螺桿膨脹(zhang)機和三個濕蒸汽 ORC 模塊(kuai)化發電廠(chang)(chang)提供動力。
然而(er)，GDC 的(de)蒸汽含有 3.3% 的(de) NCG，這是一個“巨大(da)的(de)百分(fen)比”，他說(shuo)。如果 Sosian 使用傳統的(de)蒸汽輪機(ji)，他們需要(yao)將蒸汽膨脹(zhang)至(zhi) 6 bar 絕(jue)對壓力，然后(hou)每小時消耗超過 30 噸的蒸(zheng)汽(qi)(qi)(qi)，使用(yong)蒸(zheng)汽(qi)(qi)(qi)噴射器和真(zhen)空泵去除(chu) NCG。相反，Sosian 使用(yong)蒸(zheng)汽(qi)(qi)(qi)螺桿膨脹機和底部循環來處理飽和蒸(zheng)汽(qi)(qi)(qi)排放，在整個過程(cheng)中(zhong)將蒸(zheng)汽(qi)(qi)(qi)降低(di)到(dao)大(da)氣水平，同時消除(chu)真(zhen)空系統通(tong)常(chang)消耗的寄生(sheng)功率。
“與(yu)傳統蒸(zheng)汽輪機相比，整體效率對于該站點(dian)來(lai)說是一個(ge)巨大的(de)改變，”湯炎博士說道。“該項目只需要保證 33.25 兆瓦(wa)，目標是 35 兆瓦(wa)，但我們(men)實(shi)際上(shang)發電量為 37 兆瓦(wa)。”同時(shi)，該項目不需要額外購買(mai)10%的蒸汽(qi)用于蒸汽(qi)噴射器，從而減輕(qing)了GDC的負擔(dan)，他說。
閑(xian)置地熱井的解決方案
湯炎(yan)博士表示，該(gai)系統的(de)模(mo)塊(kuai)化(hua)設計也(ye)有(you)(you)利(li)于(yu)(yu)加(jia)快(kuai)施(shi)工(gong)速度，更重要的(de)是(shi)，有(you)(you)助于(yu)(yu)克服新冠疫情帶來(lai)的(de)供應鏈和項目管理挑戰。他說(shuo)，開(kai)山通(tong)常(chang)會(hui)在(zai)(zai)六到九個月的(de)時(shi)間(jian)內(nei)組(zu)(zu)裝(zhuang)模(mo)塊(kuai)并在(zai)(zai)工(gong)廠環境(jing)中進(jin)行組(zu)(zu)件測試。“然后，當(dang)我(wo)們運送到現場時(shi)，通(tong)常(chang)只需(xu)很短的(de)時(shi)間(jian)即可將它(ta)們組(zu)(zu)裝(zhuang)在(zai)(zai)一起，并且您無(wu)需(xu)對電源模(mo)塊(kuai)進(jin)行任何焊接，”他補(bu)充道。“有(you)(you)時(shi)，質(zhi)量控制可能是(shi)一個挑戰，”他指出。
他還(huan)說(shuo)，Sosian Menegai 項目的(de)成功迄今已(yi)引起人們(men)對肯尼亞地熱(re)產業的(de)極大興趣(qu)。一個關鍵原因(yin)是肯尼亞有(you)很(hen)多井(jing)(jing)，估計其(qi)中 25% 到(dao) 30% 的(de)井(jing)(jing)可能沒(mei)有(you)蒸汽收集系統，而蒸汽收集系統是集中式蒸汽渦輪機所必需的(de)。“他們(men)稱這(zhe)些井(jing)(jing)為(wei)閑置井(jing)(jing)或廢棄井(jing)(jing)，它們(men)就(jiu)放在那里，什(shen)么也不做”，即使鉆探這(zhe)些井(jing)(jing)的(de)成本很(hen)高，“但我(wo)們(men)的(de)技術沒(mei)有(you)這(zhe)種限制，因(yin)為(wei)我(wo)們(men)可以使用任何良好(hao)的(de)壓力(li)，無論它們(men)是產生鹽水還(huan)是蒸汽。”
— Sonal Patel 是 POWER 的高級編(bian)輯（@sonalcpatel, @POWERmagazine）