دانلود مقاله نیروگاه های زمین گرمایی در تولید برق شبکه

چکیده

مقدمه

انرژی زمین گرمایی و تولید برق

فن آوری، طراحی و ساخت نیروگاه های سرچاهی

تاثیر تولید برق معمولی و سرچاهی

نتایج و بحث

نتیجه گیری

خط مشی و توصیه های کلی

منابع

Abstract

Introduction

Geothermal energy and electric power generation

Wellhead power plants technology, design and construction

Impact of conventional and wellhead power generation

Results and discussion

Conclusions

Policy and general recommendations

References

چکیده

     انرژی زمین گرمایی نقش مهمی در انتقال جهانی به سیستم‌های انرژی تجدیدپذیر و کم کربن ایفا می‌کند، زیرا توانایی آن در تامین برق پایدار و انعطاف‌پذیر به ویژه برای تقاضای بار پایه به دلیل رقابت‌پذیری هزینه آن در مقایسه با گزینه‌های انرژی سوخت فسیلی است. با این حال، زمین گرمایی با چالش زمان طولانی توسعه پروژه با نیروگاه های معمولی که به طور متوسط   5 تا 10 سال طول می کشد و با خطرات بالا مرتبط با حفاری چاه های غیرمولد مواجه است که سرمایه گذاری خصوصی و استقرار سریع را منع می کند. اگرچه انرژی زمین گرمایی پتانسیل عظیمی برای تولید برق دارد، اما در حال حاضر کمتر از 1 درصد از ظرفیت تولید برق جهان را تشکیل می دهد. ظرفیت تولید از 8.7 گیگاوات در سال 2005 به 15.61 گیگاوات در پایان سال 2020 افزایش یافت که نشان دهنده رشد متوسط   سالانه 4.01٪ است. هدف کلی این مطالعه تعیین پتانسیل، ویژگی ها و کاربرد نیروگاه های سرچاهی در تولید برق برای تکمیل و جایگزین نیروگاه های مرکزی بود. مشخص شد که نیروگاه های سرچاهی می توانند به طور موقت در طول توسعه پروژه یا به طور دائم به عنوان تاسیسات تولید متصل به شبکه یا خارج از شبکه مورد استفاده قرار گیرند. با فناوری فعلی، ژنراتورهای سرچاهی تا ظرفیت 15 مگاوات را می توان بر روی پدهای چاه چاه های تولیدی برای تامین برق موقت یا دائمی نصب کرد. ژنراتورهای سرچاهی می‌توانند استفاده بهینه از منابع را به ویژه برای چاه‌هایی با شرایط منحصربه‌فرد مانند فشار و دمای خیلی بالا یا خیلی پایین در مقایسه با سایر چاه‌های موجود در همان بخار تسهیل کنند. آنها عموماً به دلیل عدم صرفه جویی در مقیاس نسبت به نیروگاه های مرکزی پایین تر هستند، بنابراین هزینه واحد برق بالاتر است. پذیرش موفقیت‌آمیز نیروگاه‌های سرچاهی برای برق‌رسانی سریع‌تر مستلزم حمایت و مشوق‌های دولتی از نظر یارانه‌ها، توسعه گید برق، خوراک جذاب در تعرفه‌ها و مشوق‌های مالیاتی است که بدون آن‌ها با نیروگاه‌های مرکزی مرسوم رقابت مطلوبی نخواهند داشت. به طور کلی، نیروگاه های سرچاهی می توانند پروژه های برق زمین گرمایی را با کاهش موانع در سرمایه گذاری و تولید برق اولیه و درآمد برای سرمایه گذاران امکان پذیرتر کنند. با این حال، اگر زمان بین حفاری اولین چاه مولد و تکمیل یک کارخانه مرکزی بیش از یک سال باشد، سرمایه گذاری به صورت موقت منطقی اقتصادی است. مشوق هایی مانند خوراک بالا در تعرفه ها و مشوق های مالیاتی ممکن است برای رقابتی کردن آنها در برابر نیروگاه های معمولی برتر ضروری باشد.

توجه! این متن ترجمه ماشینی بوده و توسط مترجمین ای ترجمه، ترجمه نشده است.

Abstract

     Geothermal energy has a significant role to play in the global transition to renewable and low-carbon energy systems because of its ability to supply steady and flexible electricity particularly for baseload demand because of its cost competitiveness compared to fossil fuel energy options. However, geothermal faces a challenge of long project development times with conventional power plant taking an average of 5–10 years and with high risks associated with drilling of unproductive wells which discourage private investment and quick deployment. Although geothermal energy has a huge potential for power generation, it currently contributes less than 1% of global electricity generation capacity. The generation capacity grew from 8.7 GWe in 2005 to 15.61 GWe at the end of the year 2020, representing average annual growth of 4.01%. The overall objective of this study was to determine the potential, features and application of wellhead power plants in electricity generation both to complement and substitute central powerplants. It was established that wellhead power plants can be used on temporary basis during the project development or permanently as grid connected or off grid generation facilities. With current technology, wellhead generators of up to 15 MW capacity can be installed on well pads of production wells for temporary or permanent electricity supply. Wellhead generators can facilitate optimum resource utilization especially for wells with unique conditions like too high or too low pressure and temperature compared to others in the same steam. They are generally inferior to central power plants due to lack of economies of scale hence higher unit cost of power. Successful adoption of wellhead powerplants for faster electrifications calls for state support and incentives in terms of subsidies, development of electricity gid, attractive feed in tariffs and tax incentives without which they won't compete favorably against the conventional central powerplants. Generally, wellhead powerplants can make geothermal electricity projects more feasible with reduced barriers in investment and early electricity and revenue generation for investors. However, investment on temporary basis makes reasonable economic sense if the time between drilling the first productive well and completion of a central plant is more than one year. Incentives like high feed in tariffs and tax incentives may be necessary to make them competitive against the superior conventional powerplants.

Introduction

     There is a global consensus and resolution to transition to renewable and low-carbon energy systems, which has generated interest in geothermal electricity particularly due to its ability to supply competitively priced electric power reliably and with desirable flexibility to meet base load steady energy demand and fluctuating demand for intermediate and base load energy demand compared with variable renewable sources like wind and solar PV depending on a power grid's needs [1]. The challenges of greenhouse gas emissions and climate change have generated significant interest and demand for renewable sources of energy like geothermal which has the ability to supply continuous and steady energy supply ideal for base load heat and power application [2,3]. It takes about 5–10 years from the time the first well drilled to the time of central geothermal power plant commissioning for operation and maintenance while wellhead powerplants take between 3 months and 6 months from the time of completion of well drilling and testing to commissioning time for power generation, operation and maintenance of the plant [[4], [5], [6], [7]]. In central power plant development, upon drilling the well, it must be shut in until enough wells are drilled and the powerplant is constructed ready for commissioning and operation [8,9]. Upon successful geothermal well drilling and testing in central powerplant development, it is possible to utilize these productive wells for electricity generation using wellhead generating unit (WGU) on temporary basis to supply power for field operations or to the grid until the powerplant is constructed and hence the need to connect it to the many production wells which would otherwise be idle, some for very many years [10].

Conclusions

     Geothermal energy has a significant role to play in the global transition to renewable and low-carbon energy systems because of its ability to supply steady and flexible electricity particularly for baseload demand because of its cost competitiveness with fossil fuel energy options. However, geothermal faces a challenge of long project development times with conventional power plant taking average of 5–10 years and with high risks associated with drilling and unproductive wells which discourage private investment and quick deployment. Although geothermal energy has a huge potential for power generation, it currently contributes less than 1% of global electricity generation capacity. The generation capacity grew from 8.7 GWe in 2005 to 15.61 GWe in 2020, representing average annual growth of 4.01%. Wellhead and central geothermal powerplants can adopt various conversion technologies that are common to both although to different sizes. The main reason why geothermal generation growth is low and hence limited contribution is that it takes a very long time between the time the first viable resource is established and the time to construct and operate a central powerplant which exerts financial pressure to financiers and developers. It is this challenge that wellhead generators can be used to address by putting to immediate use the wells that have been drilled and tested. The main difference between wellhead power plants and the conventional powerplants is that wellhead power plants often use steam from one or in some cases few closely located geothermal production wells with limited steam pipeline connections and steam field development.