Course syllabus

Course-PM

Humanity is facing a tremendous challenge in limiting climate changes caused by the anthropogenic use of fossil energy sources. Most of the world’s leaders has agreed that something must be done. As an example, the European Union has decided to reduce the amount of carbon dioxide emitted from the member countries with 20% until the 2020 and after that another 20% until 2030. In addition, the European Council supports a proposal suggesting a reduction of emitted greenhouse gases with 95% until the year of 2050. However, despite these environmental goals formulated by the EU and other international constellations, the United Nations presented in 2018 that the 2 degree target will not be reached unless something drastic happens. Already today we can read about occurring consequences of the ongoing climate change such as a rising sea level and extreme weather occurring more often than ever.

To mitigate climate change, and to work towards a more sustainable society, actions are needed across all sectors e.g. agriculture and transportation. Focus for this course is, however, on thermal heat and power production plants. Even though the share of renewable power production has increased, the fossil-based power plants are, both globally and from a European perspective, still responsible for the main share of power production. The high share of intermittent sources has, however, caused changes in operational patterns of thermal power plants. Thermal power plants originally designed for base load power generation have to more and more act as top load plants. As top load plants they have to ramp up and down to follow the demand (Figure 1). Combined cycle thermal power plants might even need to start-up and shut down on daily basis or several times over the course of a week, even if they were conceived for base load generation. Therefore, flexible and transient operation is becoming of increasing importance in thermal power generation. Such a transient operation will have a huge influence on the performance of the plant affecting efficiency as well as emissions.

Figure 1. Example of load variation for a coal fired power plant connected to a power grid with a large share of intermittent power generation. To the left, variations in maximum continuous rating (MCR) as a function of time during 24 hours. To the right, MCR as a function of time during one week.

Switching from coal to biogenic and waste derived fuels are one of the proposed ways to reduce CO₂ emissions from power generation and industrial furnaces. Due to the different composition between coal and these other fuels, it is, however, not only a question of switching fuel, but also how to handle the problems that arise. One such problem is the high temperature corrosion (HTC) which is a problem that affects the heat transfer surfaces in a boiler. HTC is caused mainly by alkali-based salts that easily are deposited on heat transfer surfaces and are also corrosive. Compounds that contain alkali metals and chlorine are among the most aggressive agents, which is why HTC is primarily a problem for power plants that are fired with bio- and waste-fuels rather than coal.

A second alternative to significantly reduce CO₂ emissions is to apply carbon capture where the CO₂ is separated from the flue gas and later used or stored to prevent it to be emitted to the atmosphere. An interesting alternative is to combine combustion of biogenic fuels and carbon capture which has the potential to reduce the atmospheric CO₂ concentration. The capture part can be performed in different ways but always comes with an extra energy requirement reducing the efficiency and increasing the investment and operational cost compared to not applying carbon capture.

Figure 2. View of Nordjyllandsværket a Danish coal fired power plant. (source: Vattenfall)	Figure 3. The waste fired Lillesjö CHP plant in Udevalla, Sweden. (source: Uddevalla Energi)

It is a tremendous effort that has to be put in to the heat and power production sector to be able to adopt to the new situation it is facing and at the same time keep emissions like SO_X, NO_X and particulates below emission limits. The plant design is important in order to find a solution. In this course the design opportunities of modern power plants will be discussed as well as the potential of modernizing older power plants. This is done by looking into the design of coal, natural gas and waste or biomass based combined heat and power plants. Their similarities and differences will be discussed from a thermodynamic point of view. Theoretical knowledge gained will then be applied in a project work, consisting of simulations of these different power plants (Figure 4). When building different models, the students will be able to see how the performance of a power plant changes by, for example, adding a carbon capture unit or switching fuel from coal to biomass. Combined with the theoretical background given during lectures the student will also understand why the power plant behaves in a certain way and be able to evaluate different thermal power plants with respect to overall performance, regional energy system and emission regulations.

Figure 4. Example of a model built using Ebsilon Professional, the software used for power plant simulations in this course.

Course administration

MEN120 Heat and power systems engineering (7.5 hp) is given in lp1 by the division of Energy Technology at the department of Space, Earth and Environment. Klas Andersson is the examiner of the course and shares the main responsibility of the course with Thomas Allgurén. In addition to Klas and Thomas, also Chahat, Guillermo, Gulnara, Isabel and Rubén is a part of the teaching team. Finally, Lars Strömberg is taking part in the course as a guest lecturer. Lars is currently CEO for Vasa Värme and has previously been working for Vatenfall involved in their work with carbon capture and storage.

Contact details                           
Klas Andersson                               klon@chalmers.se      
Thomas Allgurén                            thomas.allaguren@chalmers.se         
Rubén Mocholí Montañés        mochol@chalmers.se  
Chahat Mandviwala                     chahat@chalmers.se
Gulnara Shavalieva                       gulnara.shavalieva@chalmers.se       
Isabel Cañete Vela                         canete@chalmers.se   
Guillermo Martinez Castilla    castilla@chalmers.se  

Course purpose

The purpose of this course is to give students a good insight into power plant engineering. The course focuses on production of heat and electric power in thermal power plants. Students will also get an overview on how such plants fit into the energy system, including aspects on distribution of heat and electricity as well as principles of the electricity market. After completing the course, students will be able to perform a thorough analysis of the efficiency and environmental performance of a Combined Heat and Power (CHP) plant, as required for making investment decisions regarding construction of a greenfield CHP plant within a district heating system. In addition, students will be able to use a state-of-the-art process simulation tool to evaluate the performance of thermal power plants.

Schedule

For schedule see TimeEdit or the schedule document for more details.

Course literature

The main literature used in this course include the book Khartchenko, N. V, Advanced Energy Systems, Taylor& Francis, Washington. The book can be borrowed from the Division of Energy Technology. The course literature also include material handed out during the lectures and the Case study project description.

Course design

There are three parts of the course, lectures, problem solving sessions and the case study which is a group exercise. The lectures comprises theory and engineering knowledge looking on design aspects of thermal power plants using solid and gaseous fuels as feed stock; renewable and fossil. The main components of steam and combined cycle power plants are presented in lectures and further studied based on hand calculations during the problem-solving sessions. Lectures and problem-solving sessions will give the student a theoretical understanding of the differences between different power plant configurations from a thermodynamic point of view as well as with respect to emissions and an energy system perspective. Lectures are given according to the provided schedule with the different topics specified. The problem-solving sessions will also follow given schedule and reflect on what has been discussed during recent lectures. It is not mandatory, but the students are highly recommended to look at the provided example problems relevant for a given session on forehand. Main responsible for lectures and problem-solving sessions are Klas, Rubén and Thomas.

The third part, the case study, is performed by the students in groups of 2. The case study includes modeling of thermal heat and power plants using a commercial software (EBSILON®Professional), which is a state-of-the-art process modelling tool. The simulation tool makes it possible to compare different designs and concepts for thermal power generation. In this way the students have a possibility to further evaluate and analyze what has been discussed during lectures and problem-solving sessions gaining a deeper understanding of the theory and how it links to the design of an actual power plant. To increase the understanding of power plants from a practical point of view even further, a mandatory field trip to a modern combined heat and power plant is arranged. This plant will also be the inspiration for one of the power plants modeled in the case study. There are several hours scheduled for the students to work with the case study in computer rooms with teachers available for supervision. The case study will be supervised mainly by Chahat, Guillermo, Gulnara and Isabel who will be present during these sessions. The students are expected to also work with the case study outside of these computer-sessions and the software will be available in several computer rooms at Chalmers and may also be installed on a personal PC. The case study project runs throughout the course and is examined in two steps. First part of the project shall be presented orally by each group during a mid-course seminar. At the end of the course shall also a written report be handed in, covering the entire project. The students are also given the opportunity to hand in a draft report before submission of the final report. Handing in a draft report is not compulsory but highly recommend since it provides an opportunity for the students to get feed back prior to handing in the final report.

Lecture material, example problems, case study instructions etcetera will be available to download from the Canvas home page. All hand ins will also be submitted via Canvas. General information from the teachers to all students will be provided via Canvas and e-mail. Individual communication between teachers and students, e.g. a student having a question regarding a modelling problem, should however be done via e-mail.

Changes made since the last occasion

Only minor changes will be done for this year with slightly updated lecture materials.

Learning objectives and syllabus

At the end of this course, students should be able to analyse and evaluate new heat and power plants. After completing the course, students will be aware of the technological options and environmental problems and opportunities associated with these options. The main generic skills developed within this course include the ability to apply thermodynamics to thermal processes for heat and electric power generation and to analyze opportunities for investment in a new CHP plant in an existing energy system. Specific learning outcomes are:

• To know the main technological options for generation of heat and electric power, including both existing technologies as well as new technologies in the development stage
• To be able to perform thermodynamic analysis of thermal power plants in different design modes
• To be able to analyze the environmental impact from different types of power plants and to know which cleaning technologies to apply
• To be able to use a state-of-the-art process simulation tool in order to establish the process flowsheet schematic of a CHP plant and to determine the performance of the plant.

Study plan

Examination form

To pass the course (grade 3) the student must; take part in the study visit, participate and give a presentation at the mid-course seminar, have an approved case study report and score at least 12 out of 24 points on the written exam. The written exam also provides the opportunity to get grade 4 or 5 with a score of at least 16 or 20 points respectively. Once all four compulsory parts are approved the student will be given the same grade on the course as he or she got on the written exam. The written exam is consisting of one theory and one calculation section with the total point divided equally between the two sections. Examples of previous exams will be provided during the course. Steam and air properties tables will be handed out during the written exam if needed. In addition, Mollier chart and calculator with cleared memory are allowed aids during the written exam.

Dates for compulsory events in the course 2019-2020

Study visit                                            September 11 2019   
Mid-course seminar                      September 26 2019   
Hand in of Case study report  October 17 2019       
Written exam                                   October 29 2019       
Re-exam                                              January 08 2020       
Re-exam                                              August  2020