This work is aimed to design and implement software for simulating operational properties of heat pumps and process data from measurements. Work contains the issue of heat pumps, their principle of functionality, different types of systems and coefficients used for rating of efficiency of heat pumps. Next it contains physical or electrical parameters that needs to be measured by designed system. The result is functional software, which contains mathematical library written in C++ and graphical user interface written in C#.

Master thesis is focused on design of ground heat pump with direct evaporation. First part is dedicated to description of heat pump technology, cooling circulation and sources of low-potential heat. Heat pump ground-water, its main components, classification of refridgerant and systems of direct evaporation are all described in the second part. The last part consists of design of each individual component of heat pump and solution of ground heat exchanger for direct evaporation of refridgerant.

This diploma thesis deals with the design of thermodynamic heat pump, used to utilize thermal energy of flue gases arised from the combustion of natural gas in a heat exchanger. The flow rates of the compader compressor, bypass compressor and turbine are calculated. Part of this thesis is simplified design of gearbox and economical evaluation of heat pump installation. The appendix of the thesis contains technical documentation.

A steady-state numerical model of a PV/microchannel integrated direct-expansion CO2 heat pump (PV-DXHP) water heater is developed, validated, and analyzed in the present study. To accomplish the objectives, a numerical model of a microchannel evaporator integrated into a CO2 PV DXHP is developed and validated. The effects of evaporator operating parameters on the heat absorption and pressure drop are analyzed. Utilizing the evaporator model, the PV-DXHP model is developed, and the baseline values of the heat pump operating parameters are determined from the evaporator parametric study. The PV-DXHP demonstrates high water heating capability, while maintaining a reasonably high COP. The COP has the highest dependency on the CO2 mass flow rate, while the water outlet temperature has the highest dependency on the water mass flow rate. The results are highly promising and indicate the system has potential to help meet the energy requirements for residential and industrial water heating demands.

The diploma thesis is concerned with selection of the optimal heat pump for model family house heating (and domestic hot water – DHW - preparation) where the preferred aspect is the fastest economic return. As a part of the diploma thesis there is an introduction into the heat pumps field and also heat pumps dividing according to their lowpotential heat withdrawing. Calculating part includes both heat loss and electric energy consumption calculation of the object. Moreover there is stated a presentation of leading heat pump producers in the Czech Republic, including their price bids which are compared with their economic return. In conclusion there is presented an economic comparison of electric energy consumption of the object which is provided with the heat pump in contrast to other regular heating systems.

The influence of control strategies and storage tank sizes on the system performance of a solar thermal assisted ground source heat pump(SAGSHP) installation has been investigated. The system investigated is in the design stage and will be implemented in the project Slottsholmen in Västervik, Sweden during 2015. Using the simulation software TRNSYS the suggested system has been modelled in its entirety and the response of the system for different control strategies and storage tank size configurations have been investigated.The system is designed with a dual tank configuration where solar heat can either be used for direct domestic hot water(DHW) production(in a high grade tank) or utilized as additional source for the heat pumps(in a low grade tank) with the purpose of increasing evaporation temperatures of the heat pumps. Four different control strategies have been investigated. Two strategies where either tank is prioritized, one where the two tanks are run in series and heat can be delivered at two temperature levels simultaneously and one strategy where the low grade storage tank is by-passed and heat is only utilized directly for DHW production. For each control strategy a series of different tank size configurations have been tested. Results show that the influence of control strategies dominate the effect of different storage tank size configurations. Solar fraction for the system varies between 0.10 and 0.13 between control strategies while variations between storage tank sizes are close to negligible. The electricity use of the SAGHSP system has been compared to a reference system where the solar collectors are switched off. The results show that fractional energy savings of the SAGSHP system ranges from 0.066 to 0.099 between control strategies. Interestingly the fractional energy savings increases for cases with lower solar fraction. For control strategies which prioritize DHW production the temperature level in the solar collector loop increased thus leading to lower solar collector efficiency and less collected heat. However, solar heat used directly for DHW production leads to a higher electricity savings than using the heat as source for the heat pumps which explains the decoupling of fractional energy savings from solar fraction. An attempt to quantify the value of the harvested solar collected heat is done by introducing a performance figure named ''Solar Savings Efficiency'' which is the ratio of the electricity savings compared to the reference system to the collected solar heat. The Solar Savings Efficiency ranges from 0.23 to 0.46 with the higher value registered for strategies which prioritize DHW production. / Inverkan av strategier för styrning och ackumuleringsvolymer på systemprestandan hos en solkollektorassisterad bergvärmeinstallation har undersökts. Det undersökta systemet är i projekteringsstadiet och kommer att byggas i projektet Slottsholmen i Västervik under 2015. Genom att använda simuleringsmjukvaran TRNSYS har systemet modellerats i sin helhet och systemets respons på olika styrstrategier och konfiguration av ackumulatortankar har undersökts. Systemet är designat med två ackumuleringstankar för solkollektorkretsen där solvärme antingen kan användas för direkt beredning av varmvatten(en varm tank) eller som värmekälla för systemets värmepumpar(en kall tank) med syftet att då höja värmepumparnas förångningstemperatur. Fyra olika styrstrategier har undersökts. Två strategier där antingen den varma eller den kalla tanken är prioriterad, en strategi där båda tankarna är i serie och värme kan lämnas vid båda temperaturnivåer samtidigt samt en fjärde strategi där den kalla tanken alltid förbigås och solvärmen endast används för direkt beredning av varmvatten. För varje styrstrategi har en rad olika konfigurationer på ackumuleringstankarna testats. Resultatet visar att inverkan av styrstrategier dominerar över den effekt som olika ackumuleringsvolymer har. Andelen av systemets värmelast som betjänas av solvärme varierar mellan 0.10 och 0.13 mellan olika styrstrategier medan variation mellan olika ackumuleringsvolymer är nära försumbar. Elanvändningen i systemet har jämförts mot ett referenssystem där solkollektorerna är avstängda. Resultaten visar att besparingen i elektricitet relativt referenssystemet varierar mellan 6.6 % och 9.9 % mellan olika styrstrategier. Intressant är att elbesparingen är högre för fall med lägre andel solvärme. För styrstrategier som prioriterar varmvattenberedning ökar temperaturnivån i solkollektorkretsen vilket leder till lägre verkningsgrad för solkollektorerna och därmed lägre andel solvärme som förs in i systemet. Dock visas att solvärme som används direkt för varmvattenberedning leder till högre elbesparing än solvärme som används som källa för värmepumparna vilket förklarar den lägre elanvändningen vid lägre andel solvärme. Ett försök att kvantifiera värdet av den skördade solvärmen har utförts genom att introducera ett nyckeltal kallat ''Solbesparingsverkningsgrad (Solar Savings Efficiency)''. Nyckeltalet är definierat som kvoten av elbesparingen för en viss strategi/konfiguration jämfört med referenssystemet och total mängd solenergi som skördats. Solbesparingsverkningsgraden varierar mellan 0.23 och 0.46 med det högre värdet för strategier som prioriterar direkt varmvattenberedning.

In recent years a growing interest in Borehole Heat Exchangers (BHEs) has been shown in Europe thanks to the increase of installations in systems connected to Ground Source Heat Pumps (GSHPs) used for heating and cooling needs. Different geometries and technical solutions have been de- veloped in order to improve heat exchange with the ground, accompanied by several descriptive models. Recently, innovative technologies as optical fiber for a new Distributed Thermal Response Test (DTRT) have been proposed. This method allows the quantification of the BHE local perfor- mances, so that a more accurate punctual analysis of thermal phenomena is allowed. The aim of this thesis is to locate an analytical model thanks to the most recent data, to achieve the definition of overall efficiency of a single BHE in terms of thermal resistance and of a BHE-GSHP system in terms of evaluation of the Coefficient of Performance. This model accuracy will be verified with new measures in a real installation. A particular attention will be given to the thermal-fluid-dynamics aspects, defining semi-empirical correlation for free and forced convection within the BHE groundwater filling.

Absorption Heat Pumps (AHP) have been developed since the late 19th century. They enable to produce cooling and heating directly from a heat source, unlike Compression Heat Pumps that require mechanical work. In the context of scarcity of resources and global warming, the company Helioclim develops solar air conditioning using an Absorption Heat Pump. The heat is gathered at rooftop solar concentrators and powers an ammonia-water AHP. The present study proposes an EES model of Helioclim’s AHP allowing assessing its performances under various operating conditions. Another aspect developed is the Modelling of the whole system (from solar energy to the economic assessment) in order to find the best parameters to propose to a potential client. Regarding EES model, three existing EES examples of AHP have been used. Those models, ranging from the simple single-stage ammonia AHP to a more complex GAX-cycle, did not correspond exactly to the features of Helioclim’s cycle. Therefore, a new model has been built: the position of the GAX and its connections to the other heat exchangers have been adapted and a recirculation in the generator has been proposed in order to correspond to Helioclim’s design. The model obtained is then used to assess the improvement of the performances with the GAX. It is also compared to the available experimental data. In the present study, a software program representing the whole solar air conditioning system is also developed, integrating the previous EES model. The software program considers the solar energy gathered by the collectors and deduces the energy transmitted to the heat pump. The EES model is then used to assess the performances of the heat pump in the operating conditions, allowing determining the produced cooling and heating. An economic and energy synthesis is produced, summarizing effectively the parameters and economic advantages of the installation. This software program allows sizing an installation for a client much more quickly than before.

Heat production accounted in 2021 for 50 % of the energy end use globally, where a strongconnection to fossil sources still exists. Large-scale electrical heat pumps can therefore have akey role in the energy system to enable a decreased reliance on fossil fuels and at the same timecontribute to stable system when incorporating more intermittent renewable sources. To operatea heat pump, a working fluid i.e., refrigerant is required. Historically these substances havebeen ozone depleting with a significant global warming potential. Applied regulations andlegislations have therefore limited the substances possible to implement. This study therefore focuses on investigating potential future refrigerants in LSHPs, by studying both current and potential future legislations and regulations but also the potential performanceof the substances. The performance was evaluated for two operational condition cases wherethe first focused on meeting the supply and demand of a third generation district heating systemwith an evaporation temperature of 0 °C. The second case investigated a middle temperature industrial process with an evaporation temperature of 33 °C. For both cases a two-stage compressor heat pump cycle was considered. Substances available in the database REFPROP were considered, where legislations and regulations, classifications, thermodynamic properties, and the performance were investigated. Substances not fulfilling the set criterions were eliminated. Seven substances were then investigated in depth where e.g., the volume flow rate, performance, operational electricity cost and both footprint and cost of the evaporator were considered. All substances were investigated both with and without an internal liquid-suction HEX, to investigate how such component potentially could affect the performance. The result of the study shows that environmental, safety aspects and thermodynamic propertieshave a large impact on possible refrigerants, with a decrease from 160 available substances to20 possible for each case. If an evaporation pressure in the vacuum range or a transcritical cyclewould have been investigated the number of possible refrigerants would increase. Out of the 20possible substances, seven substances namely isobutane, butane, isobutene, butene, propane,perfluoropentane and isopentane were chosen for further investigation. The performance andelectrical operational cost can be concluded to be fairly similar, with an increase when includingan internal liquid-suction HEX. The performance for case 2, is although slightly higher, whereperfluoropentane performs superior. The high GWP value for perfluoropentane however limitsits possibility to be used. Lastly the size and cost of the evaporator was investigated. It couldbe concluded that case 1 required a smaller design than case 2, related to the size of the HTCvalue.

This report is a case study about geothermal energy system and its application forthe hospital in the city of Gävle. Today the hospital uses district heating and -coolingas their main energy source.There is a report about the hospital in the city of Umeå where geothermal energyhas been installed. Both hospitals have the same need when it comes to using heatand cooling all year round. The hospital in Umeå installed geothermal energy sothat they got a less vulnerable energy system. The emissions of CO2 were also lowereddue to this installation.This report aims to answer the following research question.How geothermal energy can be a option of choice for the hospital I the city ofGävle?The report presents a literature study on subject close to this research question. Focusfor the report is to find out if increased electricity consumption is better than usinglocal district heating- and cooling. The report from the geothermal installation inUmeå has on big difference and that is from which fuels the district heating is produced.In Gävle the energy comes from biomass which gives that the emission factoris almost zero.The calculations and modelling are performed in Excel and the results presented ingraphs.The results are positive both from an economical view and environmental perspective.If the total electricity price doesn’t increase more than 36% per year then geothermalenergy is more cost effective. Looking at the emissions of CO2 equivalentswith an emission factor of 90.4 kg per MWh electricity the COP-factor should notbe lower than 7.5. If that can be reached, then geothermal energy performs betterthan district heating- and cooling.