This thesis considers the problem of implementation of Model Predictive Control (MPC) strategies in the general area of Heating, Ventilation, Air Conditioning (HVAC). Specifically, the contributions utilize the constraint handling and optimality properties of MPC to achieve energy efficient control of many different HVAC systems. First, the thesis focuses on a linear offset-free MPC design for a vapor compression cycle. The key contributions include a a sequential tuning method and application to a detailed simulation test-bed, demonstrating superior closed-loop results to that of traditional control strategies in the presence of both disturbances and measurement noise. Next, a modified linear offset-free MPC formulation is implemented on a heat pump. The key contribution is the formulation of an optimization problem that recognizes the tradeoff between energy conservation and tracking performance. Simulation results illustrate superior performances as measured through three separate metrics: safety, energy efficiency and tracking. The implementation of MPC formulations to these realistic problems also pointed to a lack of MPC formulations with explicit performance considerations in the control design. Thus, in the final part of the thesis, these observed shortcomings in the standard offset-free linear MPC design are addressed via a new performance specification-based MPC. Desired closed-loop output response is specified and achieved through a tiered optimization formulation that can handle plant model mismatch. Superior closed-loop response, in terms of desired transient behavior and disturbance rejection, relative to standard linear-based and offset-free MPC designs is achieved. Finally, directions for future work are discussed. / Thesis / Doctor of Philosophy (PhD)

Исследование влияния отопительных систем и конструктивных особенностей на энергетическую и экономическую эффективность индивидуальных жилых зданий. / The most effective variant of a heating system and a constructive system for increasing the energy and economic efficiency of an individual residential building are proposed.

<p dir="ltr">Building cooling and ventilation account for nearly 10% of the global electricity consumption. In fact, a recent study even showed that, globally, dehumidification consumes more energy than sensible cooling. One high-efficiency dehumidification technology is selective membrane dehumidification. Selective membranes allow water vapor transport but block air transport. There are two overarching gaps in the literature that are addressed in this dissertation: (1) vacuum membrane dehumidification (VMD) has been rigidly defined as an isothermal process and (2) literature on one of the most efficient VMD system designs, which I will refer to as the “dual module humidity pump,” is limited to ideal thermodynamic modeling (no experimental demonstration or practical system modeling in the current literature).</p><p dir="ltr">This work presents a novel system concept, referred to as the “Active Membrane Energy Exchanger” (AMX), which specifically couples VMD and air cooling into one process to provide the first non-isothermal VMD system concept. The present study provides a wholistic understanding of the benefits and limitations of the AMX approach through both thermodynamic system modeling and experimental protype development and demonstration.</p><p dir="ltr">System models developed in Engineering Equation Solver were used to compare the energy performance of the AMX to other HVAC technologies. These models showed that the AMX could achieve up to 25% annual cooling electricity savings in commercial buildings and up to 60% annual cooling electricity savings in 100% outdoor air applications. Experiments showed that combining cooling and dehumidification increased membrane permeance by up to 40% and increased dehumidification performance by 3-6%. Further demonstration showed the prototype could remove up to 45% of the humidity in the humid air flow but struggled to reject all of that vapor to the exhaust air (mass transfer imbalance). This discovery enabled a practical thermofluid model to estimate theoretical and practical COP limits, which were approximately 40 and 10, respectively. Additionally, a global sensitivity analysis on the new model showed that mechanical design is far more limiting to the performance than material design.</p><p dir="ltr">In summary, this dissertation develops and demonstrates a novel air conditioning technology, from system modeling to prototype demonstration. This work was funded and guided by industry partners, and the results of this dissertation are a major step towards real-world implementation.</p>

No description available.

Energy efficiency is a growing field that concerns more and more companies, individuals as well as governments in order to reduce costs and use less energy for a more sustainable development. Engie is no exception and values energy efficient projects. In this paper will be documented three energy efficiency related projects that I carried out during my five month end of studies internship. This work spans different topics, the parallel operation of hydraulic distribution pumps, the modeling of an heat exchangers as well as pid calculations for a dedicated ehating network. We delve into the technical aspect of each subject before introducing the tools developed, with some of their results. / Energieffektivisering är ett växande område som berör allt fler företag, privatpersoner såväl som myndigheter för att minska kostnaderna och använda mindre energi för en mer hållbar utveckling. Engie är inget undantag och värdesätter energieffektiva projekt. I den här artikeln kommer tre energieffektivitetsrelaterade projekt att dokumenteras som jag genomförde under min fem månder långa praktikperiod. Detta arbete spänner över olika ämnen, parallelldrift av hydrauliska distributionspumpar, modellering av en värmeväxlare samt pid-beräkningar för ett dedikerat värmenätverk. Vi fördjupar oss i den tekniska aspekten av varje ämne innan vi introducerar de utvecklade verktygen, med några av deras resultat.

Can a tool effectively aid user experience (UX) and user interface (UI) designers, along with frontend developers, in implementing more energy efficient websites? The foundation for formulating the thesis questions and identifying the issue was laid through an exploration of related work. This study aims to present the development of a tool encompassing recommendations and practices from existing research, providing valuable support for designers and developers.  Several methods, namely six, were established to better define and concretise the problems. The idea phase continued exploring potential solution both through looking at similar solutions as well as doing workshops together with potential users. In this phase the guidelines, now named SCOPES - System Conscious of Potential Energy Saving, started taking shape. The prototype was designed to assist web designers and developers in reducing energy consumption during website development. The study and especially the test phase found that guidelines empowered web designers to create energy efficient web pages, and users accept lower energy pages when aware of their efficiency, given that essential functionalities are retained.  The results of this thesis, supported by a total of 16 methods and 64 users with various backgrounds, ethnicities, and genders, emphasize the importance of addressing the challenges, posed by our energy-demanding society, pointing to potential pathways for a more sustainable and efficient future.

No description available.

No description available.

No description available.

No description available.