Dynaamisen lämmönsiirtomallin kehittäminen

Dynaamisia simulointimalleja tarvitaan, jotta voidaan tarkastella järjestelmän käyttäytymistä ajan funktiona. Simulointimallilla voidaan simuloida järjestelmän lähtö erilaisilla herätteillä. Mallin avulla saadaan myös tarkempi käsitys järjestelmästä ja sen osa-alueista, koska simulointimallista voidaan tarkastella sellaisia asioita, jotka voivat olla oikeasta järjestelmästä vaikeasti mitattavia. Tässä työssä kehitetään LUT Energian hyötysuhdemittapaikan keskikokoista kalorimetriä approksimoiva dynaaminen lämmönsiirtomalli käyttäen Matlab® Simulink -ohjelmistoa. Kehitetyn lämmönsiirtomallin tarkkuutta arvioidaan todellisella järjestelmällä tehdyillä mittauksilla. Työssä käytetään karkeita approksimaatioita, jotka tulee korvata tarkemmilla matemaattisilla malleilla jatkokehitystä varten. Työssä kehitetty dynaaminen lämmönsiirtomalli approksimoi todellisen järjestelmän vastetta lämmitysvaiheessa keskimääräisenvirheen ±0,19 °C tarkkuudella.

Energy efficiency parameters in variable speed drives

The main purpose of this thesis is to measure and evaluate how accurately the current energy saving calculation in ABB’s new variable speed drive ACS850 works. The main topic of this thesis is energy-efficiency parameters. At the beginning of this thesis centrifugal pump, squirrel cage motor and variable speed drive, including some equations related to them, are being introduced. Also methods of throttling control and variable speed drive control of centrifugal pumps are being introduced. These subjects are introduced because the energy saving calculation in ACS850 is related to the centrifugal pumps usually driven by squirrel cage motors. The theory also includes short section about specific energy of pumping. Before measurements the current energy saving calculation of ACS850 is being introduced and analyzed. The measurements part includes introduction of measuring equipment, measurement results, summary and analysis of the measurements. At the end of this thesis a proposal for an improvement to the current energy saving calculation is being introduced and few proposals are made for new energy-efficiency parameters, which could be added to variable speed drives. At the end are also thoughts

Environmental policy instruments concerning industrial end-use energy efficiency

Energy efficiency and saving energy are the main question marks when thinking of reducing carbon dioxide emissions or cutting costs. The objective of thesis is to evaluate policy instruments concerning end-use energy efficiency of heavy industry in European Union. These policy instruments may be divided in various ways, but in this thesis the division is to administrative, financial, informative and voluntary instruments. Administrative instruments introduced in this thesis are Directive on Integrated Pollution Prevention and Control, Directive on Energy End-use Efficiency and Energy Services, and Climate and Energy Package. Financial means include energy and emission taxation, EU Emission Trading Scheme and diverse support systems. Informative instruments consist of horizontal BAT Reference Document for Energy Efficiency, as well as substantial EU documents including Green Paper on Energy Efficiency, Action Plan for Energy Efficiency and An Energy Policy for Europe. And finally, voluntary instruments include environmental managements systems like ISO 14001 and EMAS, energy auditing and benchmarking. The efficiency of different policy instruments vary quite a lot. Informative instruments lack the commitment from industry and are thus almost ineffective, contrary to EU Emission Trading Scheme, which is said to be the solution to climate problems. The efficiency of administrative means can be placed between those mentioned and voluntary instruments are still quite fresh to be examined fruitfully. However, each instrument has their potential and challenges. Cases from corporate world strengthen the results from theoretical part. Cases were written mainly on the basis of interviews. The interviewees praised the energy efficiency contract of Finnish industry, but the EU ETS takes the leading role of policy instruments. However, for industry the reductions do not come easily.

Induction Motor Drive Energy Efficiency - Simulation and Analysis

A coupled system simulator, based on analytical circuit equations and a finite element method (FEM) model of the motor has been developed and it is used to analyse a frequency-converterfed industrial squirrel-cage induction motor. Two control systems that emulate the behaviour of commercial direct-torque-controlled (DTC) and vector-controlled industrial frequency converters have been studied, implemented in the simulation software and verified by extensive laboratory tests. Numerous factors that affect the operation of a variable speed drive (VSD) and its energy efficiency have been investigated, and their significance in the simulation of the VSD results has been studied. The dependency of the frequency converter, induction motor and system losses on the switching frequency is investigated by simulations and measurements at different speeds for both the vector control and the DTC. Intensive laboratory measurements have been carried out to verify the simulation results.

Evaluation of energy efficiency and best available techniques in pumping processes

The potential for enhancing the energy efficiency of industrial pumping processes is estimated to be in some cases up to 50 %. One way to define further this potential is to implement techniques in accordance to definition of best available techniques in pumping applications. These techniques are divided into three main categories: Design, control method & maintenance and distribution system. In the theory part of this thesis first the definition of best available techniques (BAT) and its applicability on pumping processes is issued. Next, the theory around pumping with different pump types is handled, the main stress being in centrifugal pumps. Other components needed in a pumping process are dealt by presenting different control methods, use of an electric motor, variable speed drive and the distribution system. Last part of the theory is about industrial pumping processes from water distribution, sewage water and power plant applications, some of which are used further on in the empirical part as example cases. For the empirical part of this study four case studies on typical pumping processes from older Master’s these were selected. Firstly the original results were analyzed by studying the distribution of energy consumption between different system components and using the definition of BAT in pumping, possible ways to improve energy efficiency were evaluated. The goal in this study was that by the achieved results it would be possible to identify the characteristic energy consumption of these and similar pumping processes. Through this data it would then be easier to focus energy efficiency actions where they might be the most applicable, both technically and economically.

Energy Efficiency of Pumping Medium Consistency Pulp with Centrifugal Pump

Approximately a quarter of electrical power consumption in pulp and paper industry is used in different pumping systems. Therefore, improving pumping system efficiency is a considerable way to reduce energy consumption in different processes. Pumping of wood pulp in different consistencies is common in pulp and paper industry. Earlier, centrifugal pumps were used to pump pulp only at low consistencies, but development of MC technology has made it possible to pump medium consistency pulp. Pulp is a non-Newtonian fluid, which flow characteristics are significantly different than what of water. In this thesis is examined the energy efficiency of pumping medium consistency pulp with centrifugal pump. The factors effecting the pumping of MC pulp are presented and through case study is examined the energy efficiency of pumping in practice. With data obtained from the case study are evaluated the effects of pump rotational speed and pulp consistency on energy efficiency. Additionally, losses caused by control valve and validity of affinity laws in pulp pumping are evaluated. The results of this study can be used for demonstrating the energy consumption of MC pumping processes and finding ways to improve energy efficiency in these processes.

Solution Business Model for Energy Efficiency

This study examined solution business models and how they could be applied into energy efficiency business. The target of this study was to find out, what a functional solution business model applied to energy efficiency improvement projects is like. The term “functionality” was used to refer not only to the economic viability but to environmental and legal aspects and also to the implement of Critical Success Factors (CSFs) and the ability to overcome the most important market barriers and risks. This thesis is based on a comprehensive literature study on solution business, business models and energy efficiency business. This literature review was used as a foundation to an energy efficiency solution business model scheme. The created scheme was tested in a case study which studied two different energy efficiency improvement projects, illustrated the functionality of the created business model and evaluated their potential as customer targets. Solution approach was found to be suitable for energy efficiency business. The most important characteristics of a good solution business model were identified to be the relationship between the supplier and customer, a proper network, knowledge on the customer’s process and supreme technological expertise. Thus the energy efficiency solution business was recognized to be particularly suitable for example for energy suppliers or technological equipment suppliers. Because the case study was not executed from a certain company’s point of view, the most important factors such as relationships and the availability of funding could not be evaluated. Although the energy efficiency business is recognized to be economically viable, the most important factors influencing the profitability and the success of energy efficiency solution business model were identified to be the proper risk management, the ability to overcome market barriers and the realization of CSFs.

The energy efficiency of chilled beam systems in an office building at different climates

Besides the sustaining of healthy and comfortable indoor climate, the air conditioning system should also achieve for energy efficiency. The target indoor climate can be ob-tained with different systems; this study focuses on comparing the energy efficiency of different air conditioning room unit systems in different climates. The calculations are made with dynamic energy simulation software IDA ICE by comparing the indoor cli-mate and energy consumption of an office building with different systems in different climates. The aim of the study is to compare the energy efficiency of chilled beam systems to other common systems: variable air volume, fan coil and radiant ceiling systems. Besides the annual energy consumption also the sustainability of target indoor climate is compared between the simulations. Another aim is to provide conclusions to be used in the product development of the chilled beam systems’ energy efficiency. The adaptable chilled beam system and the radiant ceiling system prove to be energy efficient independent of the climate. The challenge of reliable comparison is that other systems are not able to reach the target indoor climate as well as the others. The complex calculation environment of the simulation software, made assumptions and excluding of the financial aspects complicate comparing the big picture. The results show that the development of the chilled beam systems should concentrate on energy efficient night heating, flexible demand based ventilation and capacity control and possibilities on integrating the best practices with other systems. 

Energy Efficiency of a Diesel-Electric MobileWorking Machine

The power demand of many mobile working machines such as mine loaders, straddle carriers and harvesters varies significantly during operation, and typically, the average power demand of a working machine is considerably lower than the demand for maximum power. Consequently, for most of the time, the diesel engine of a working machine operates at a poor efficiency far from its optimum efficiency range. However, the energy efficiency of dieseldriven working machines can be improved by electric hybridization. This way, the diesel engine can be dimensioned to operate within its optimum efficiency range, and the electric drive with its energy storages responds to changes in machine loading. A hybrid working machine can be implemented in many ways either as a parallel hybrid, a series hybrid or a combination of these two. The energy efficiency of hybrid working machines can be further enhanced by energy recovery and reuse. This doctoral thesis introduces the component models required in the simulation model of a working machine. Component efficiency maps are applied to the modelling; the efficiency maps for electrical machines are determined analytically in the whole torque–rotational speed plane based on the electricalmachine parameters. Furthermore, the thesis provides simulation models for parallel, series and parallel-series hybrid working machines. With these simulation models, the energy consumption of the working machine can be analysed. In addition, the hybridization process is introduced and described. The thesis provides a case example of the hybridization and dimensioning process of a working machine, starting from the work cycle of the machine. The selection and dimensioning of the hybrid system have a significant impact on the energy consumption of a hybrid working machine. The thesis compares the energy consumption of a working machine implemented by three different hybrid systems (parallel, series and parallel-series) and with different component dimensions. The payback time of a hybrid working machine and the energy storage lifetime are also estimated in the study.

Energy Efficiency Consideration in Electric Vehicle Transmission

This study is a survey of benefits and drawbacks of embedding a variable gearbox instead of a single reduction gear in electric vehicle powertrain from efficiency point of view. Losses due to a pair of spur gears meshing with involute teeth are modeled on the base of Coulomb’s law and fluid mechanics. The model for a variable gearbox is fulfilled and further employed in a complete vehicle simulation. Simulation model run for a single reduction gear then the results are taken as benchmark for other types of commonly used transmissions. Comparing power consumption, which is obtained from simulation model, shows that the extra load imposed by variable transmission components will shade the benefits of efficient operation of electric motor. The other accomplishment of this study is a combination of modified formulas that led to a new methodology for power loss prediction in gear meshing which is compatible with modern design and manufacturing technology.

Applying Nordic Energy Efficiency and Renewable Energy Solutions in Kaliningrad Oblast, Russia

RENSOL (Regional Energy Solutions) project deals with the use of energy efficiency and renewable energy solutions in Kaliningrad Oblast to tackle climate change. Overall objective of the RENSOL work package 1 is to build awareness and knowledge on solutions for energy efficient buildings and street lightning applications. The project report describes available solutions to improve housing energy efficiency.

Belt conveyor energy efficiency analysis and energy model development

An energy model of a belt conveyor was designed. Operation of a belt conveyor was researched. Operational indexes were calculated. Energy optimization process and recommendations were presented.

Concentration of hydrogen peroxide and improving its energy efficiency

Distillation is a unit operation of process industry, which is used to separate a liquid mixture into two or more products and to concentrate liquid mixtures. A drawback of the distillation is its high energy consumption. An increase in energy and raw material prices has led to seeking ways to improve the energy efficiency of distillation. In this Master's Thesis, these ways are studied in connection with the concentration of hydrogen peroxide at the Solvay Voikkaa Plant. The aim of this thesis is to improve the energy efficiency of the concentration of the Voikkaa Plant. The work includes a review of hydrogen peroxide and its manufacturing. In addition, the fundamentals of distillation and its energy efficiency are reviewed. An energy analysis of the concentration unit of Solvay Voikkaa Plant is presented in the process development study part. It consists of the current and past information of energy and utility consumptions, balances, and costs. After that, the potential ways to improve the energy efficiency of the distillation unit at the factory are considered and their feasibility is evaluated technically and economically. Finally, proposals to improve the energy efficiency are suggested. Advanced process control, heat integration and energy efficient equipment are the most potential ways to carry out the energy efficient improvements of the concentration at the Solvay Voikkaa factory. Optimization of the reflux flow and the temperatures of the overhead condensers can offer immediate savings in the energy and utility costs without investments. Replacing the steam ejector system with a vacuum pump would result in savings of tens of thousands of euros per year. The heat pump solutions, such as utilizing a mechanical vapor recompression or thermal vapor recompression, are not feasible due to the high investment costs and long pay back times.

Framework for Regional Heating Energy Efficiency Assessment

The aim of this project was to develop general framework for systematic assessment of energy efficiency of heating on regional level in Russia. The framework created during this project includes two main instruments, namely: general regional heating energy efficiency assessment model (REEMod) and general regional heating energy efficiency assessment criteria for housing areas (REECrit). Framework pays extreme attention to realization of energy saving, overall cost efficiency and comfortable indoor climate. Life-cycle ideology was applied during creation of the framework. Application of the framework can provide decision-making process with systematically collected and processed information on current state of areas energy efficiency. Such information will help decision makers to evaluate current situation of the whole energy chain, to compare different development scenarios and to identify the most efficient improvement methods, thus supporting realization of regions efficient energy management. Simultaneous pursuit of energy savings, cost efficiency and indoor air quality can contribute to development of sustainable community. Presented instruments should be continuously developed further as an iterative process based on knew experience, development of technology and overall understanding of energy efficiency issues.