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Abstract

The research provides a thermodynamic analysis of the theoretical model of a ventilation and air conditioning heat pump system with the ventilation air cold energy recovery depending on outside air parameters, the recovery efficiency and characteristics of a premise. A confectionery production workshop was taken as a prototype where technological conditions (temperature and humidity) must be maintained during the warm season. Calculations using the method of successive approximations to estimate air parameters at system’s nodal points were conducted. It allowed to determine theoretical refrigeration efficiency of the studied system and proved advantages of heat recuperation for smaller energy consumption. The model can be applied for design of heating, ventilation, and air conditioning units which work as a heat pump. The studied system has the highest energy efficiency in the area of relatively low environment temperatures and relative humidity which is suitable for countries with temperate continental climates characterized by low relative humidity.
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Bibliography

[1] Zhang J., Zhang H.-H., He Y.-L., Tao W.-Q.: A comprehensive review on advances and applications of industrial heat pumps based on the practices in China. Appl. Energ. 178(2016), 800–825.
[2] Chwieduk D.: Analysis of utilization of renewable energies as heat sources for heat pumps in building sector. Renew. Energ. 9(1996), 720–723.
[3] Khrustaliov B.M.: Heat Supply and Ventilation. ASV, Moscow 2007 (in Russian).
[4] Mazzeo D.: Solar and wind assisted heat pump to meet the building air conditioning and electric energy demand in the presence of an electric vehicle charging station and battery storage. J. Clean. Prod. 213(2019), 1228–1250.
[5] Chwieduk B., Chwieduk D.: Analysis of operation and energy performance of a heat pump driven by a PV system for space heating of a single family house in Polish conditions. Renew. Energ. 165(2021), 117–126.
[6] Bezrodny M., Prytula N., Tsvietkova M.: Efficiency of heat pump systems of air conditioningfor removing excessive moisture. Arch. Thermodyn. 40(2019), 2, 151–165.
[7] Bezrodny E.K., Misiura T.O.: The heat pump system for ventilation and air conditioning inside the production area with an excessive internal moisture generation. Eurasian Phys. Tech. J. 17(2020), 118–132.
[8] Adamkiewicz A., Nikonczuk P.: Waste heat recovery from the air preparation room in a paint shop. Arch. Thermodyn. 40(2019), 3, 229–241.
[9] Szreder M.: Investigations into the influence of functional parameters of a heat pump on its thermal efficiency. Teka. Commission of Motorization and Energetics in Agriculture 13(2013), 191–196.
[10] Redko A., Redko O., DiPippo R.: Low-Temperature Energy Systems with Applications of Renewable Energy. Academic Press, Elsevier, 2020.
[11] Morozjuk T.V.: The Theory of Chillers and Heat Pumps. Studija “Negociant”, Odessa 2006 (in Russian).
[12] Jaber S., Ezzat A.W.: Investigation of energy recovery with exhaust air evaporative cooling in ventilation system. Energ. Buildings 139(2017), 439–448.
[13] Bozhenko M.F.: Heat Sources and Heat Consumers. NTUU KPI “Politehnika”, Kyiv 2004 (in Ukrainian).
[14] State Building Standards of Ukraine DBN B.2.5-67: 2013, “Heating, ventilation and air conditioning”. Ministry of Regional Development, Construction and Housing of Ukraine, Kyiv 2013 (in Ukrainian).
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Authors and Affiliations

Myhailo Kostiantynovych Bezrodny
1
Tymofii Oleksiyovych Misiura
1

  1. National Technical University of Ukraine, Igor Sikorsky, Kyiv Polytechnic Institute, Prosp. Peremohy 37, 03056 Kyiv, Ukraine
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Abstract

The article addresses the issues falling within the scope of the economic analysis of a detached building’s heating system with a direct evaporation ground source heat pump installation. The paper was elaborated based on the data made available by the investment’s contractor and the investor. The paper provides data on the investment expenditures and utility cost, calculations of the installation payback, internal return rate and the current net value.
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Authors and Affiliations

Karol Tucki
Michał Sikora
Magdalena Karlikowska
Wojciech Będkowski
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Abstract

Research in termoacoustics began with the observation of the heat transfer between gas and solids. Using this interaction the intense sound wave could be applied to create engines and heat pumps. The most important part of thermoacoustic devices is a regenerator, where press of conversion of sound energy into thermal or vice versa takes place. In a heat pump the acoustic wave produces the temperature difference at the two ends of the regenerator. The aim of the paper is to find the influence of the material used for the construction of a regenerator on the properties of a thermoacoustic heat pump. Modern technologies allow us to create new materials with physical properties necessary to increase the temperature gradient on the heat exchangers. The aim of this paper is to create a regenerator which strongly improves the efficiency of the heat pump.
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Authors and Affiliations

Bartłomiej Kruk
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Abstract

The numerical simulation of the heat transfer in the flow channels of the minichannel heat exchanger was carried out. The applied model was validated on the experimental stand of an air heat pump. The influence of louver heights was investigated in the range from 0 mm (plain fin) to 7 mm (maximum height). The set of simulations was prepared in Ansys CFX. The research was carried out in a range of air inlet velocities from 1 to 5 m/s. The values of the Reynolds number achieved in the experimental tests ranged from 93 to 486. The dimensionless factors, the Colburn factor and friction factor, were calculated to evaluate heat transfer and pressure loss, respectively. The effectiveness of each louver height was evaluated using the parameter that relates to the heat transfer and the pressure drop in the airflow. The highest value of effectiveness (1.53) was achieved by the louver height of 7 mm for the Reynolds number of around 290.
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Authors and Affiliations

Artur Romaniak
1
Michał Jan Kowalczyk
1
Marcin Łęcki
1
Artur Gutkowski
1
Grzegorz Górecki
1

  1. Lodz University of Technology, Zeromskiego 116, 90-924 Łódz, Poland
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Abstract

HVAC systems use a substantial part of the whole energy usage of buildings. The optimizing of their operation can greatly affect the power use of a building, making them an interesting subject when trying to save energy. However, this should not affect the comfort of the people inside. Many approaches aim to optimize the operation of the heating and cooling system; in this paper, we present an approach to steer the heat pumps to reduce energy usage while aiming to maintain a certain level of comfort. For this purpose, we employ a market-based distributed method for power-balancing. To maintain the comfort level, the market-based distributed system assigns each device a cost-curve, parametrized with the current temperature of the room. This allows the cost to reflect the urgency of the HVAC operation. This approach was tested in a real-world environment: we use 10 heat pumps responsible for temperature control in 10 comparable-sized rooms. The test was performed for 3 months in summer. We limited the total peak power, and the algorithm balanced the consumption of the heat pumps with the available supply. The experiments showed that the system successfully managed to operate within the limit (lowering peak usage), and - to a certain point - reduce the cost without significantly deteriorating the working conditions of the occupants of the rooms. This test allowed us to estimate the minimal peak power requirement for the tested set-up that will still keep the room temperatures in or close to comfortable levels. The experiments show that a fully distributed market-based approach with parametrized cost functions can be used to limit peak usage while maintaining temperatures.
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Authors and Affiliations

Weronika Radziszewska
1
ORCID: ORCID
Marcin A. Bugaj
2
ORCID: ORCID
Mirosław Łuniewski
1
ORCID: ORCID
Gerwin Hoogsteen
3
ORCID: ORCID
Patryk Chaja
1
ORCID: ORCID
Sebastian Bykuć
1
ORCID: ORCID

  1. Institute of Fluid-Flow Machinery Polish Academy of Science, ul. Fiszera 14, 80-231 Gdańsk, Poland
  2. Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, ul. Nowowiejska 21/25, 00-665 Warsaw, Poland
  3. Department of Electrical Engineering, Mathematica and Computer Science,University of Twente, PO BOX 217, 7500 AE Enschede, Netherlands
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Abstract

In the paper a heating system with a vapour compressor heat pump and vertical U-tube ground heat exchanger for small residential house is considered. A mathematical model of the system: heated object - vapour compressor heat pump - ground heat exchanger is presented shortly. The system investigated is equipped, apart from the heat pump, with the additional conventional source of heat. The processes taking place in the analyzed system are of unsteady character. The model consists of three elements; the first containing the calculation model of the space to be heated, the second - the vertical U-tube ground heat exchanger with the adjoining area of the ground. The equations for the elements of vapour compressor heat pump form the third element of the general model. The period of one heating season is taken into consideration. The results of calculations for two variants of the ground heat exchanger are presented and compared. These results concern variable in time parameters at particular points of the system and energy consumption during the heating season. This paper presents the mutual influence of the ground heat exchanger subsystem, elements of vapour compressor heat pump and heated space.

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Authors and Affiliations

Małgorzata Hanuszkiewicz-Drapała
Jan Składzień
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Abstract

This paper presents the results of thermodynamic analyses of a system using a horizontal ground heat exchanger to cool a residential building in summer and heat it in the autumn-winter period. The main heating device is a vapour compression heat pump with the ground as the lower heat source. The aim of the analyses is to examine the impact of heat supply to the ground in the summer period, when the building is cooled, on the operation of the heating system equipped with a heat pump in the next heating season, including electricity consumption. The processes occurring in cooling and heating systems have an unsteady nature. The main results of the calculations are among others the time-dependent values of heat fluxes extracted from or transferred to the ground heat exchanger, the fluxes of heat generated by the heat pump and supplied to the heated building by an additional heat source, the parameters in characteristic points of the systems, the temperature distributions in the ground and the driving electricity consumption in the period under analysis. The paper presents results of analysis of cumulative primary energy consumption of the analyzed systems and cumulative emissions of harmful substances.

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Authors and Affiliations

Małgorzata Hanuszkiewicz-Drapała
Tomasz Bury
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Abstract

The dynamic performance of cylindrical double-tube adsorption heat pump is numerically analysed using a non-equilibrium model, which takes into account both heat and mass transfer processes. The model includes conservation equations for: heat transfer in heating/cooling fluids, heat transfer in the metal tube, and heat and mass transfer in the adsorbent. The mathematical model is numerically solved using the method of lines. Numerical simulations are performed for the system water-zeolite 13X, chosen as the working pair. The effect of the evaporator and condenser temperatures on the adsorption and desorption kinetics is examined. The results of the numerical investigation show that both of these parameters have a significant effect on the adsorption heat pump performance. Based on computer simulation results, the values of the coefficients of performance for heating and cooling are calculated. The results show that adsorption heat pumps have relatively low efficiency compared to other heat pumps. The value of the coefficient of performance for heating is higher than for cooling

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Authors and Affiliations

Kinga Kowalska
Bogdan Ambrożek
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Abstract

Chemical heat pumps (CHP) use reversible exothermal and endothermal chemical reactions to increase the temperature of working fluids. In comparison to the “classical” vapour compression chemical heat pumps, CHP enables us to achieve significantly higher temperatures of a heated medium which is crucial for the potential application, e.g. for production of superheated steam. Despite the advantages presented, currently, there are no installations using CHP for lowgrade waste heat recovery available on the market. The scaling up of industrial processes is still one of the greatest challenges of process engineering. The aim of the theoretical and experimental concept study presented here was to evaluate a method of reclaiming energy from low temperature waste streams and converting it into a saturated steam of temperature from 120 to 150 ◦C, which can be useful in industry. A chemical heat pump concept, based on the dilution and concentration of phosphoric acid, was used to test the method in the laboratory scale. The heat of dilution and energy needed for water evaporation from the acid solutionwere experimentally measured. The cycle of successive processes of dilution and concentration has been experimentally confirmed. A theoretical model of the chemical heat pump was tested and coefficient of performance measured.

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Authors and Affiliations

Marzena Czapnik
Michał Tylman
Maciej Jaskulski
Paweł Wawrzyniak
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Abstract

By the emergence of distributed energy resources, with their associated communication and control complexities, there is a need for an efficient platform that can digest all the incoming data and ensure the reliable operation of the power system, which can be achieved by using digital twins. The paper discusses the advantages of using digital twins in the development of control systems and operation of distributed heat and electric power generation facilities. The possibilities of using the digital doubles for increasing the efficiency of the considered objects is presented as the example of optimizing the configuration of a control system of solar collectors in the presence of heat losses in pipelines of the external circuit. Further, the total balance consumed and generated electric and heat energy are presented. Examples of algorithms for protecting equipment to improve security are given, and the possibilities of improving the reliability of distributed power systems are considered. The system use of the digital twins provides the possibility of developing and debugging control algorithms, which increase the efficiency, reliability and safety of control objects, including distributed thermal and electrical power generation complexes.
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Authors and Affiliations

Makhsud Mansurovich Sultanov
1
Edik Koirunovich Arakelyan
1
Ilia Anatolevich Boldyrev
1
Valentina Sergeevna Lunenko
1
Pavel Dmitrievich Menshikov
1

  1. National Research University MPEI, Krasnokazarmennaya 17, Moscow, 111250 Russia
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Abstract

Energy management plays a crucial role in cabin comfort as well as enormously affects the driving range. In this paper energy balances contemplating the implementation of a heat pump and an expansion device in battery electric vehicles are elaborated, by comparing the performances of refrigerants R1234yf and R744, from –20°C to 20°C. This work calculates the coefficient of performance, energy requirements for ventilation (from 1 to 5 people in the cabin) and energy required with the implementation of a heat pump, with the employment of a code in Python with the aid of Cool- Prop library. The work ratio is also estimated if the work recovery device recuperates the work during the expansion. Comments on the feasibility of the implementation are as well explicated. The results of the analysis show that the implementation of an expansion device in an heat pump may cover the energy requirement of the compressor from 27% to more than 35% at 20°C in cycles operating with R744, and from 15% to more than 20% with refrigerant R1234yf, considering different compressor efficiencies. At –20°C, it would be possible to recuperate between around 30 and 24%. However, the risk of suction when operating with R1234yf at ambient temperatures below –10°C shows that the heat pump can only operate with R744. Thus, it is the only refrigerant that achieves the reduction of energy consumption at these temperatures.
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Authors and Affiliations

Maria Laura Canteros
1
Jiri Polansky
2

  1. Czech Technical University in Prague, Jugoslávských partyzánu 1580/3, 160 00 Prague 6 – Dejvice, Czech Republic
  2. ESI Group, Brojova 16, 326 00 Plzen, Czech Republic
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Abstract

Adsorption cooling and desalination technologies have recently received more attention. Adsorption chillers, using eco-friendly refrigerants, provide promising abilities for low-grade waste heat recovery and utilization, especially renewable and waste heat of the near ambient temperature. However, due to the low coefficient of performance (COP) and cooling capacity (CC) of the chillers, they have not been widely commercialized. Although operating in combined heating and cooling (HC) systems, adsorption chillers allow more efficient conversion and management of low-grade sources of thermal energy, their operation is still not sufficiently recognized, and the improvement of their performance is still a challenging task. The paper introduces an artificial intelligence (AI) approach for the optimization study of a two-bed adsorption chiller operating in an existing combined HC system, driven by low-temperature heat from cogeneration. Artificial neural networks are employed to develop a model that allows estimating the behavior of the chiller. Two crucial energy efficiency and performance indicators of the adsorption chiller, i.e., CC and the COP, are examined during the study for different operating sceneries and a wide range of operating conditions. Thus this work provides useful guidance for the operating conditions of the adsorption chiller integrated into the HC system. For the considered range of input parameters, the highest CC and COP are equal to 12.7 and 0.65 kW, respectively. The developed model, based on the neurocomputing approach, constitutes an easy-to-use and powerful optimization tool for the adsorption chiller operating in the complex HC system.
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Authors and Affiliations

Jarosław Krzywanski
1
ORCID: ORCID
Karol Sztekler
2
ORCID: ORCID
Marcin Bugaj
3
ORCID: ORCID
Wojciech Kalawa
2
ORCID: ORCID
Karolina Grabowska
1
ORCID: ORCID
Patryk Robert Chaja
4
ORCID: ORCID
Marcin Sosnowski
1
ORCID: ORCID
Wojciech Nowak
2
ORCID: ORCID
Łukasz Mika
2
ORCID: ORCID
Sebastian Bykuć
4
ORCID: ORCID

  1. Jan Dlugosz University in Czestochowa, Faculty of Science and Technology, ul. A. Krajowej 13/15, 42-200 Czestochowa, Poland
  2. AGH University of Science and Technology, Faculty of Energy and Fuels, ul. A. Mickiewicza 30, 30-059 Cracow, Poland
  3. Warsaw University of Technology, Faculty of Power and Aeronautical Engineering, ul. Nowowiejska 24, 00-665 Warsaw, Poland
  4. Institute of Fluid-Flow Machinery Polish Academy of Sciences, Department of Distributed Energy, ul. Fiszera 14, 80-952 Gdansk, Poland
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Abstract

In recent years, European countries have experienced a noteworthy surge in the interest surrounding renewable energy sources, particularly the integration of photovoltaic (PV) panels with various types of heat pumps. This study aims to evaluate the energy performance of a grid19 connected hybrid installation, combining a PV array with an air-source heat pump (AHP), for domestic hot water preparation in a residential building located in Cracow, Poland. The primary focus of this evaluation is to assess the extent to which self-consumption (SC) of energy can be increased. The study utilizes Transient System Simulation Tool 18 software to construct and simulate various system models under different scenarios. These scenarios include building electricity consumption profiles, PV power systems, and the specified management of AHP. Analyses were conducted over a period of 1 year to assess the operational performance of the systems. In the considered installations, the differences in SC values between PV installation ranged from 9 to 25%. Notably, the highest SC values were observed during the winter months. AHP with operation control allows to obtain in some months of the year up to 35% higher value the SC parameter compared to systems without AHP. The highest annual 29 SC value recorded reached 83.9%. These findings highlight the crucial role of selecting an appropriate PV system size to maximize the SC parameter.
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Authors and Affiliations

Sebastian Pater
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Chemical Engineering and Technology, Warszawska 24, 31-155 Cracow, Poland
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Abstract

The paper presents selected issues relating to the energy analysis of the air heat pump for hot water. Experimental studies on a test stand made it possible to verify the operational parameters of the heat pump under actual conditions of use. The study shows that heating the water in the storage tank with the capacity of 130 dm3 from 25°C to 40°C took approximately 60 minutes and the water heating for another 5°C took 30 minutes longer. The heat pump process in the field of higher water temperature in the tank is less effective, thus heating the water in the tank above 50°C is less favorable economically.
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Authors and Affiliations

Mariusz Szreder

Abstract

In this study a cooling ejector cycle coupled to a compression heat pump is analyzed for simultaneous cooling and heating applications. In this work, the influence of the thermodynamic parameters and fluid nature on the performances of the hybrid system is studied. The results obtained show that this system presents interesting performances. The comparison of the system performances with hydrofluorocarbons (HFC) and natural fluids is made. The theoretical results show that the a low temperature refrigerant R32 gives the best performance.
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Abstract

The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics.

Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points.

Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.

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Authors and Affiliations

Mikhail Bezrodny
Natalia Prytula
Maria Tsvietkova
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Abstract

Two-dimensional numerical investigations of the fluid flow and heat transfer have been carried out for the laminar flow of the louvered fin-plate heat exchanger, designed to work as an air-source heat pump evaporator. The transferred heat and the pressure drop predicted by simulation have been compared with the corresponding experimental data taken from the literature. Two dimensional analyses of the louvered fins with varying geometry have been conducted. Simulations have been performed for different geometries with varying louver pitch, louver angle and different louver blade number. Constant inlet air temperature and varying velocity ranging from 2 to 8 m/s was assumed in the numerical experiments. The air-side performance is evaluated by calculating the temperature and the pressure drop ratio. Efficiency curves are obtained that can be used to select optimum louver geometry for the selected inlet parameters. A total of 363 different cases of various fin geometry for 7 different air velocities were investigated. The maximum heat transfer improvement interpreted in terms of the maximum efficiency has been obtained for the louver angle of 16° and the louver pitch of 1.35 mm. The presented results indicate that varying louver geometry might be a convenient way of enhancing performance of heat exchangers.

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Authors and Affiliations

Tomasz Muszyński
Sławomir Marcin Kozieł
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Abstract

The effects of water-side operating conditions (mass flow rates and inlet temperatures) of both evaporator and gas cooler on the experimental as well as simulated performances (cooling and heating capacities, system coefficient of performance (COP) and water outlet temperatures) of the transcritical CO2 heat pump for simultaneous water cooling and heating the are studied and revised. Study shows that both the water mass flow rate and inlet temperature have significant effect on the system performances. Test results show that the effect of evaporator water mass flow rate on the system performances and water outlet temperatures is more pronounced (COP increases by 0.6 for 1 kg/min) compared to that of gas cooler water mass flow rate (COP increases by 0.4 for 1 kg/min) and the effect of gas cooler water inlet temperature is more significant (COP decreases by 0.48 for given range) compared to that of evaporator water inlet temperature (COP increases by 0.43 for given range). Comparisons of experimental values with simulated results show the maximum deviation of 5% for cooling capacity, 10% for heating capacity and 16% for system COP.
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Authors and Affiliations

Jahar Sarkar
Souvik Bhattacharyya

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