scholarly journals Modeling dynamics of the spacecraft power plant consisting of Stirling engine and external thermal circuit

2021 ◽  
Vol 313 ◽  
pp. 12002
Author(s):  
Aigiz Valiullin ◽  
Vladimir Zenkin

Modern space programs cover a wide range of missions, including both near-earth missions and those affecting areas of deep space. In the second case, power plants based on the conversion of thermal energy into electrical energy are often considered for the power supply of spacecraft. One of the possible thermoelectric converters is the Stirling engine. To be able to design modern power plants of spacecraft built based on Stirling engines, it is necessary to use calculation tools to simulate their operation in a wide range of modes, to take into consideration the influence of subsystems on each other and the final characteristics of the power plant. As part of the work, a thermodynamic model of an external thermal circuit was created, consisting of heat pipes, heat exchangers and radiator cooler panels. The hot thermal circuit is consisted of two parts: primary and secondary, the cold thermal circuit is consisted of only one part. A mathematical model of the free-piston Stirling engine of the first order has been also implemented. The working fluid in the engine is helium. The developed models were independently debugged and then integrated into a single model of the power plant. For each type of model, the corresponding mathematical models are presented and the basic assumptions are described. The model is implemented in an open simulation environment of xcos/scilab, examples of power plant model implementation are presented. Numerical experiments were carried out to study the dynamics of the heating of the contour elements (with independent, and then with integrated modeling) and the effect of the non-stationary thermal state on the engine performance. The article presents the basic equations and the design schemes for the power plant model, as well as some results of numerical simulation, including the dynamics of hot and cold circuit temperature changes and the dynamics of changes in the indicator diagram of the engine when the external thermal circuit is heated. The developed model can be used in the early stages of spacecraft design for a preliminary assessment of the main indicators of the power plant, its dimensions and thermal loads.

2017 ◽  
Vol 21 (2) ◽  
pp. 1153-1160 ◽  
Author(s):  
Aleksandra Borsukiewicz

The paper presents the idea of using organic substances as working fluids in vapor power plants, in order to convert the low and medium temperature thermal energy sources into electrical energy. The calculation results of the power plant efficiency for butane-ethane zeotropic mixtures of different mass compositions, for the power plant supplied with hot water having a temperature of 120?C. Based on the results of thermal-flow calculations it was found that the use of zeotropic mixture does not allow to increase the efficiency and output of the power plant (these values appeared as slightly lower ones). However, it was found that, through the selection of a mixture of sufficiently large temperature glide, the heat exchange surface of the condenser can be reduced or a co-generation system can be implemented.


ijd-demos ◽  
2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Nida Urrohmah ◽  
Karin Caroline Kelly ◽  
Fitri Yuliani

Electric Steam Power Plants (PLTU) need coal as fuel to produce electricity. The higher the electrical energy needed to eat, the more fuel will be used. This has happened in the construction of shelters 9 and 10 Suralaya Merak-Banten steam power plant (PLTU). This development is reaping various kinds of rejection because it causes environmental damage not only in the area around the development operation but also in the Greater Jakarta area. The rejection movement was initiated by local residents and supported by international Environmental NGOs.Pembangkit Listrik Tenaga Uap (PLTU) membutuhkan batu bara sebagai bahan bakar untuk menghasilkan energi listrik. Semakin tinggi energi listrik yang dibutuhkan makan akan semakin banyak bahan bakar yang digunakan. Hal ini terjadi pada pembangunan shelter 9 dan 10 PLTU Suralaya di pulau Jawa spesifiknya di daerah Merak-Banten. Pembangunan ini menuai berbagai macam penolakan karena mengakibatkan kerusakan lingkungan tidak hanya pada wilayah sekitar operasi pembangunan namun juga pada wilayah Jabodetabek. Gerakan penolakan diinisiasi tentunya oleh warga setempat dan didukung dengan NGO Internasional penggiat isu lingkungan. 


Author(s):  
Bima Sakti ◽  
Nur Rani Alham ◽  
Ahmad Nur Fajri ◽  
Ilham Rizal Ma’rif

<em>The need for electricity in Indonesia is very important considering the limited resources and the lack of manpower, making Indonesia desperately need to increase electricity generation. One source of energy that can be converted into electrical energy is tidal barrage using the tidal barrage method. The application of this energy is still very small in Indonesia but there are a number of areas that have the potential to be implemented by the power plant. Tidal power plants that utilize the potential energy contained in the differences in tides and tides of sea water by trapping water in dams and then moving water turbines and when the water turbine is connected to a generator can produce electrical energy. Related to how the output of the generated power can it is known by looking at what height the water level drives the turbine. This type of power plant is environmentally friendly because it does not damage the natural ecosystem and the dam can be used for various activities.</em><em></em>


Kilat ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 261-271
Author(s):  
Sugeng Purwanto

ABSTRACT Renewable energy is potential alternative energy to replace the central role of fossil energy which has been going on since the early 20th century. The solar power plant is alternative energy, especially for households and industry, and can be designed as a hybrid power plant consisting of solar panels, batteries, an automatic transfer switch (ATS), and a grid. This research will focus on developing ATS based on a microcontroller. It functions to regulate the load supply automatically from the three sources of electrical energy, like solar panels, batteries, and grid while the microcontroller functions to monitor the transfer of power from the solar power plant to grid and voltage movements in the system so that current and voltage data can be recorded from time to time to improve system reliability, effectiveness, and efficiency of the tool. ATS components consist of MCB, magnetic contactor, timer H3CR, relay, 2000VA inverter, solar charge controller 100A, NodeMCU ESP8266 IoT, and battery 12V 100AH. This research is conducted in one year to produce ATS based on a microcontroller that can automatically regulate the supply of loads from the three sources of electrical energy with a good level of efficiency and stability.  Keywords: solar power plants, hybrid power plants, an automatic transfer switch.  ABSTRAK Energi baru terbarukan merupakan energi alternatif yang potensial untuk menggantikan peran sentral dari energi fosil yang telah berlangsung sejak awal abad ke 20. PLTS merupakan salah satu energi alternatif penyedia energi listrik untuk rumah tangga dan industri serta dapat dirancang sebagai sistem pembangkit listrik tenaga hibrid (PLTH) yang terdiri dari panel surya, baterai, sistem pengaturan beban atau ATS (automatic transfer switch) dan jaringan PLN. Peneltian difokuskan pada pengembangan sistem ATS berbasiskan mikrokontroler. ATS berfungsi untuk mengatur suplai beban secara otomatis dari ketiga sumber energi listrik yaitu panel surya, baterai dan PLN sedangkan mikrokontroler berfungsi memonitor perpindahan daya dari PLTS ke sumber PLN dan pergerakan tegangan pada sistem sehingga dapat dilakukan pencatatan data arus dan tegangan dari waktu ke waktu sehingga dapat meningkatkan keandalan sistem, efektifitas dan efisiensi alat. Komponen ATS terdiri dari MCB, magnetic contactor, timer H3CR, relay, inverter 2000VA, solar charge controller 100A, NodeMCU ESP8266 IoT, dan baterai 12V 100Ah. Penelitian ini akan dilakukan dalam periode satu tahun menghasilkan ATS berbasiskan mikrokontroler yang dapat mengatur suplai beban secara otomatis dari ketiga sumber energi listrik dengan tingkat efisiensi dan kestabilan yang baik. Tim penelitian ini tediri dari 3 orang dan berasal dari program studi teknik elektro, IT PLN.  Kata kunci: pembangkit listrik tenaga surya, pembangkit listrik tenaga hibrid, pengaturan suplai beban.


Author(s):  
Xing L. Yan ◽  
Lawrence M. Lidsky

High generating efficiency has compelling economic and environmental benefits for electric power plants. There are particular incentives to develop more efficient and cleaner coal-fired power plants, to permit use of the world’s most abundant and secure energy source. This paper presents a newly-conceived power plant design, the Dual Brayton Cycle Gas Turbine PFBC, that yields 45% net generating efficiency and fires on a wide range of fuels with minimum pollution, of which coal is a particularly intriguing target for its first application. The DBC-GT design allows power plants based on the state-of-the-art PFBC technology to achieve substantially higher generating efficiencies while simultaneously providing modern gas turbine and related heat exchanger technologies access to the large coal power generation market.


Author(s):  
Yongju Jeong ◽  
Seongmin Son ◽  
Seong kuk Cho ◽  
Seungjoon Baik ◽  
Jeong Ik Lee

Abstract Most of the power plants operating nowadays mainly have adopted a steam Rankine cycle or a gas Brayton cycle. To devise a better power conversion cycle, various approaches were taken by researchers and one of the examples is an S-CO2 (supercritical CO2) power cycle. Over the past decades, the S-CO2 power cycle was invented and studied. Eventually the cycle was successful for attracting attentions from a wide range of applications. Basically, an S-CO2 power cycle is a variation of a gas Brayton cycle. In contrast to the fact that an ordinary Brayton cycle operates with a gas phase fluid, the S-CO2 power cycle operates with a supercritical phase fluid, where temperatures and pressures of working fluid are above the critical point. Many advantages of S-CO2 power cycle are rooted from its novel characteristics. Particularly, a compressor in an S-CO2 power cycle operates near the critical point, where the compressibility is greatly reduced. Since the S-CO2 power cycle greatly benefits from the reduced compression work, an S-CO2 compressor prediction under off-design condition has a huge impact on overall cycle performance. When off-design operations of a power cycle are considered, the compressor performance needs to be specified. One of the approaches for a compressor off-design performance evaluation is to use the correction methods based on similitude analysis. However, there are several approaches for deriving the equivalent conditions but none of the approaches has been thoroughly examined for S-CO2 conditions based on data. The purpose of this paper is comparing these correction models to identify the best fitted approach, in order to predict a compressor off-design operation performance more accurately from limited amount of information. Each correction method was applied to two sets of data, SCEIL experiment data and 1D turbomachinery code off-design prediction code generated data, and evaluated in this paper.


Author(s):  
M. A. Gotovsky ◽  
V. F. Ermolov ◽  
V. E. Mikhailov ◽  
Yu G. Sukhorukov ◽  
N. N. Trifonov

Now in Russia a new NPP “Brest – OD - 300” is developing which is to become a head in a series of fast reactors cooled by liquid lead or lead-bismuth alloy. Russian abbreviation OD is translated as Pilot-Demonstrational. The ideas are developed to use in this power plant deaeratorless thermal circuit. Such the schemes are widely and successfully used for conventional power plants in Russia. Deaeratorless thermal schemes are based on the use of direct contact low-pressure reheaters. These reheaters have deaeration ability. Such schemes improve power plants efficiency by 1.5 %. Some other deaerator functions are distributed among other elements of plant. In particular, the presence of an external, independent supply of water, which is available at nuclear power plants and much higher than the supply of water in the deaerator. Danger of return flow exists for direct-contact low pressure reheaters. But its design allows to eliminate completely the possibility of dangerous return flow. Compliance with safety was verified by calculation and in the operated power plants.


Author(s):  
Maximilian Roedder ◽  
Matthias Neef ◽  
Christoph Laux ◽  
Klaus-P. Priebe

The organic Rankine cycle (ORC) is an established thermodynamic process that converts waste heat to electric energy. Due to the wide range of organic working fluids available the fluid selection adds an additional degree-of-freedom to the early design phase of an ORC process. Despite thermodynamic aspects such as the temperature level of the heat source, other technical, economic, and safety aspects have to be considered. For the fluid selection process in this paper, 22 criteria were identified in six main categories while distinguishing between elimination (EC) and tolerance criteria (TC). For an ORC design, the suggested method follows a practical engineering approach and can be used as a structured way to limit the number of interesting working fluids before starting a detailed performance analysis of the most promising candidates. For the first time, the selection process is applied to a two-stage reference cycle, which uses the waste heat of a large reciprocating engine for cogeneration power plants. It consists of a high temperature (HT) and a low temperature (LT) cycle in which the condensation heat of the HT cycle provides the heat input of the LT cycle. After the fluid selection process, the detailed thermodynamic cycle design is carried out with a thermodynamic design tool that also includes a database for organic working fluids. The investigated ORC cycle shows a net thermal efficiency of about 17.4% in the HT cycle with toluene as the working fluid and 6.2% in LT cycle with isobutane as the working fluid. The electric efficiency of the cogeneration plant increases from 40.4% to 46.97% with the both stages of the two-stage ORC in operation.


1998 ◽  
Vol 120 (3) ◽  
pp. 566-572 ◽  
Author(s):  
X. L. Yan ◽  
L. M. Lidsky

High generating efficiency has compelling economic and environmental benefits for electric power plants. There are particular incentives to develop more efficient and cleaner coal-fired power plants in order to permit use of the world’s most abundant and secure energy source. This paper presents a newly conceived power plant design, the Dual Brayton Cycle Gas Turbine PFBC, that yields 45 percent net generating efficiency and fires on a wide range of fuels with minimum pollution, of which coal is a particularly intriguing target for its first application. The DBC-GT design allows power plants based on the state-of-the-art PFBC technology to achieve substantially higher generating efficiencies, while simultaneously providing modern gas turbine and related heat exchanger technologies access to the large coal power generation market.


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