Thesis describes the procedures for evaluating performance parameters of heat pumps COP, SCOP (coefficient of perfomance, seasonal coefficient of perfomance). It is focused on the most common types of heat pumps in european geographical conditions, heat pumps air-water, water-water, brine-water.

A ground source heat pump (GSHP) system utilizes a borehole heat exchanger to extract energy from the ground during the heating season and to deposit energy during the cooling season. This requires the drilling of an extended borehole, typically ranging from 100 to 200 meters in length, with a diameter of approximately 6 to 8 inches. Inside the borehole, a U-shaped tube is placed and surrounded by a grout that aids heat transfer between the tube and the surrounding soil. A heat transfer fluid, often a mixture of water and glycol, circulates through the tube to exchange heat with the ground. During the winter, the system draws energy from the ground for household space heating, while in the summer, when air conditioning is used, it expels energy from the house into the ground. In regions with heating-dominated climates, such as Canada, more energy is withdrawn from the ground during the winter than can be naturally restored during the summer. Consequently, the soil progressively cools over time, leading to reduced heat pump coefficient of performance and a decline in the overall system efficiency. This study explores a solution to this issue by integrating solar domestic hot water systems which employ solar thermal collectors to heat water for domestic purposes. These systems are relatively straightforward, consisting of solar thermal collectors, piping, pumps, a hot water tank, and controllers. The collector area is designed to deliver high solar fractions during the summer, but it typically exhibits lower efficiency in the winter. In Toronto, annual solar fraction, defined as the proportion of energy supplied by the solar thermal system to the total energy required by the load, typically range between 50-70%. This research aims to leverage solar thermal collectors for recharging the ground during the summer months. This approach enables the installation of larger collector areas, improving system performance in the winter, while simultaneously depositing excess energy into the ground during the summer. Notably, this study focuses on a single household located in Toronto, Canada, where the recommended solar thermal collector area is 10 square meters, and the borehole heat exchanger length is 150 meters. Also, it is assumed that four people are living in this house and required energy for heating and cooling of the house are 28000 and 7000 kWh per year, respectively. This approach offers a promising solution to balance seasonal heat transfer to the ground, mitigating the long-term decline in GSHP performance. The study demonstrates that by coupling the solar thermal system with the GSHP, the targeted outcomes are achievable. / Thesis / Master of Applied Science (MASc)

Ces dernières années, les coûts et la demande en énergie n’ont cessé d’augmenter. Par conséquent, l’humanité fait face à de graves menaces environnementales telles que l'augmentation des rejets de CO2. À cet égard, la communauté internationale doit parvenir à réduire de son empreinte carbone et à veiller à ce que les besoins en énergie thermique soient couverts de manière durable. D’importantes quantités de chaleur résiduaire à basse température (60 - 100°C) sont libérées quotidiennement dans l'atmosphère par de nombreuses installations industrielles. Les thermo-transformateurs de chaleur à absorption constituent un outil intéressant car ils peuvent revaloriser des chaleurs résiduaires pour produire de la chaleur utile pour le chauffage et la production d’eau chaude. Actuellement, les mélanges de travail utilisés dans les pompes à absorption sont les systèmes {ammoniac + eau} et {eau + bromure de lithium}. Cependant, ces deux fluides de travail présentent certains inconvénients tels que la toxicité, la cristallisation et la corrosivité. Par conséquent, il est important de rechercher de nouveaux mélanges de travail. Cette étude a pour objectif d’évaluer l’intérêt d’utiliser des mélanges constitués de liquides ioniques et d'eau au sein de thermo-transformateurs à absorption. Tout d'abord, les propriétés thermodynamiques de ces systèmes binaires (pression de vapeur, densité, capacité thermique et enthalpie d’excès) ont été mesurées dans un large domaine de température et de composition. Ces données expérimentales ont été corrélées à l’aide de modèles thermodynamiques adéquats. Ensuite, les performances de ces fluides de travail ont été évaluées. Les résultats montrent que les systèmes binaires {H2O + Ils} sont une alternative prometteuse aux fluides de travail traditionnels tels que {H2O + LiBr} / Recently, the cost and use of energy continually rise. Hence, humans are close to face serious environmental problems such as increasing CO2 discharges. In this regard, global community is to achieve the ambitious objective of reducing carbon footprint and to ensure that the heating demand is covered in a sustainable manner. Since, enormous amounts of low-temperature waste heat are released on daily bases from many industrial plants to the atmosphere at temperatures between 60 - 100°C. Absorption heat transformers (AHT) are interesting because they can recover low temperature waste heat from different industrial activities and renewable energy sources such as solar and geothermal. AHT can be used to upgrade waste heat to produce useful heat for heating and hot water supplies. Nowadays, the standard working pairs used for AHTs are {ammonia + water} and {water + lithium bromide}. However, both of the working pairs show questionable behavior such as toxicity, crystallization and corrosiveness. Therefore, exploring new working pairs which do not exhibit limitations become of great importance. This work includes an investigation to analyze the AHT systems using {water + ionic liquids} binary systems as working fluids. First, basic thermodynamic properties including vapor pressure, density, heat capacity as well as excess enthalpy of these binary systems were measured at various temperatures with different ionic liquid concentrations. The thermodynamic properties data were correlated by different equations, respectively. The correlated values were significantly consistent with the experimental data. Next, simulation of the AHT performance based on the thermodynamic properties of the new working pairs and on the mass and energy balance for each component of the system were performed. Results show that the {H2O + ILs} binary systems are promising alternatives to replace the already used {H2O + LiBr} working pairs

This diploma thesis deals with the energy efficiency of heat pumps, especially efficiency of air/water system. In the this thesis is simply described the principle of the heat pump and function of each component. It shows the issues of determining the parameters of performance of the heat pump and also describes verification in according to applicable standards. The diploma thesis gives an analysis of determining the energetical efficiency and calculation of coefficient of performance, in other words, the seasonal heating coefficient of performance. Seasonal energy efficiency of selected samples of heat pumps for the heating season is designated for specific climatic conditions.

No description available.

This thesis presents work on a holistic approach for improving the overall design of solar cooling systems driven by solar thermal collectors. Newly developed methods for thermodynamic optimization of hydraulics and control were used to redesign an existing pilot plant. Measurements taken from the newly developed system show an 81% increase of the Solar Cooling Efficiency (SCEth) factor compared to the original pilot system. In addition to the improvements in system design, new efficiency factors for benchmarking solar cooling systems are presented. The Solar Supply Efficiency (SSEth) factor provides a means of quantifying the quality of solar thermal charging systems relative to the usable heat to drive the sorption process. The product of the SSEth with the already established COPth of the chiller, leads to the SCEth factor which, for the first time, provides a clear and concise benchmarking method for the overall design of solar cooling systems. Furthermore, the definition of a coefficient of performance, including irreversibilities from energy conversion (COPcon), enables a direct comparison of compression and sorption chiller technology. This new performance metric is applicable to all low-temperature heat-supply machines for direct comparison of different types or technologies. The achieved findings of this work led to an optimized generic design for solar cooling systems, which was successfully transferred to the market.