Design of a Multigenerational System With Absorption Cooling for a Residential Community: A Case Study

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Andre Bolt ◽  
Branson Chea ◽  
Ibrahim Dincer ◽  
Martin Agelin-Chaab ◽  
Marc Rosen
Keyword(s):  
British Columbia ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Residential Community ◽  
Heating And Cooling ◽  
Absorption Cooling ◽  
Energy And Exergy

Abstract In this paper, a multigeneration system is proposed, which utilizes geothermal energy and a lithium-bromide absorption cooling cycle. The proposed system is capable of providing electricity, heating, cooling, and domestic hot water to a small residential community in Vancouver, British Columbia, Canada. The performance of the system's heating and cooling capabilities were evaluated energetically and exergetically. A case study is presented by considering human occupancy loads and the impact of building material conditions on heating and cooling. System performance was investigated using parametric studies, where the operating conditions and ambient conditions were varied. Similar systems in the open literature were found to have an energetic and exergetic coefficient of performance (COP) of 0.8 and 0.3 for heating, while the proposed multigeneration system resulted in an energetic and exergetic coefficient of performance of 1.14 and 0.63 for heating, an increase of 30–52%. Additionally, the literature revealed that some systems resulted in an energy and exergy efficiency of 26.2% and 36.6%. The proposed multigeneration system achieved an energy and exergy efficiency of 31.86% and 63.33%, an improvement of 5.66–26.73%. The study was able to utilize the existing recommendations made by British Columbia to determine the necessary heating and cooling loads while also being able to successfully generate four useful outputs with a smaller footprint than those in the literature.

scholarly journals Energy and Exergy Analysis of the Air Source Transcritical CO2 Heat Pump Water Heater Using CO2-Based Mixture as Working Fluid

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4470
Author(s):  
Yikai Wang ◽  
Yifan He ◽  
Yulong Song ◽  
Xiang Yin ◽  
Feng Cao ◽  
...  
Keyword(s):  
Exergy Analysis ◽  
Heat Pumps ◽  
Exergy Efficiency ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Domestic Hot Water ◽  
Practical Applications ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

Given the large demand nowadays for domestic hot water, and its impact on modern building energy consumption, air source transcritical CO2 heat pumps have been extensively adopted for hot water production. Since their system efficiency is limited by significant irreversibility, a CO2-based mixture could offer a promising drop-in technology to overcome this deficiency without increasing system complexity. Although many CO2 blends have been studied in previously published literature, little has been presented about the CO2/R32 mixture. Therefore, a proposed mixture for use in transcritical CO2 heat pumps was analyzed using energy and exergy analysis. Results showed that the coefficient of performance and exergy efficiency variation displayed an “M” shape trend, and the optimal CO2/R32 mixture concentration was determined as 0.9/0.1 with regard to flammability and efficiency. The irreversibility of the throttling valve was reduced from 0.031 to 0.009 kW⋅kW−1 and the total irreversibility reduction was more notable with ambient temperature variation. A case study was also conducted to examine domestic hot water demand during the year. Pure CO2 and the proposed CO2 blend were compared with regard to annual performance factor and annual exergy efficiency, and the findings could provide guidance for practical applications in the future.

Development of a Geothermal-Based Integrated Plant for Generating Clean Hydrogen and Other Useful Commodities

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Yunus Emre Yuksel ◽  
Murat Ozturk ◽  
Ibrahim Dincer
Keyword(s):  
Geothermal Energy ◽  
Hydrogen Generation ◽  
Positive Impact ◽  
Exergy Efficiency ◽  
Integrated System ◽  
Operating Conditions ◽  
Hot Water ◽  
Fluid Temperature ◽  
Geothermal Fluid ◽  
Energy And Exergy

Abstract In this study, geothermal energy is considered as a renewable energy source to finally provide various useful outputs such as electricity, hydrogen, fresh and hot water, drying, heating, and cooling. In this regard, a new geothermal power-based multigenerational system is proposed to meet these demands in an environmentally benign manner and studied thermodynamically by considering energy and exergy approaches and investigating parametrically. A combination of geothermal energy is used to achieve the most promising hydrogen generation rates and high plant performances. The results of this study indicate that the energy and exergy efficiency values of the entire plant for the selected operating conditions become 38.41% and 42.57%. In addition to the thermodynamic analysis performed, numerous parametric studies are performed to reveal how operating conditions and state parameters affect the overall system performance. According to the parametric analyses results, for given ranges, an increase in ambient temperature, separator working temperature, geothermal fluid temperature, and geothermal fluid mass flowrate have positive impact on both energy and exergy efficiency of the integrated system and useful products generation rate as well.

A Novel Thermally Activated R744 Heat Pump Cycle

2013 ◽  
Author(s):  
Luke Bannar-Martin ◽  
Peter Childs
Keyword(s):  
Gas Turbine ◽  
Heat Pump ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Inlet Temperature ◽  
Tertiary Sector ◽  
Thermally Activated ◽  
Heating And Cooling

A novel thermally activated transcritical R744 heat pump cycle, which combines the principles of both the reverse Rankine cycle and Brayton cycle has been analysed. The cycle produces simultaneous hot and cold streams at three temperature levels; 60°C for hot water, 40°C for low temperature ambient heating, 10°C for ambient cooling. The cycle has been designed to fulfil the requirements of a flexible ‘hybrid’ trigeneration scheme, where the three energy streams (electricity, heating and cooling) can be matched closely to the user demands — maximising the Energy Utilisation Factor (EUF) of the fuel. Such a system is likely to be used in environmentally resilient cities in either tertiary sector buildings, interconnected residential zones, industry or other large buildings such as hospitals and educational establishments. The cycle is activated using recuperated thermal energy from a gas turbine exhaust stream and under certain operating conditions uses a small proportion of the electricity produced by the gas turbine generator set. Recuperation is achieved using a direct exhaust gas to R744 recuperating heat exchanger. At higher levels of thermal recuperation, the increase in expander inlet temperature results in a substantial increase in the Coefficient Of Performance (COP). With an expander inlet temperature of 250°C the cycle achieves a COP in cooling of 1.13, whilst with a expander inlet temperature of 350°C the cycle achieves a COP in cooling of 1.58. These values of COP in cooling are typical of double and triple stage absorption chillers respectively. The values for COP in heating are 1.97 for an expander inlet temperature of 250°C, and 2.41 for an expander inlet temperature of 350°C. The cycle is also capable of acting as a power positive bottoming cycle, whilst still providing heating and cooling. Under these circumstances, and assuming an expander inlet temperature of 350°C, the cycle has a thermal to mechanical conversion efficiency of 9.7%. The corresponding values of COP in cooling and heating are 1.03 and 1.80 respectively.

scholarly journals Energetic and exergetic analysis of a convective drier: A case study of potato drying process

2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné
Keyword(s):  
Energy Consumption ◽  
Research Work ◽  
Specific Energy Consumption ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Convective Drying ◽  
Drying Time ◽  
Energy And Exergy ◽  
Exergy Losses

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.

scholarly journals Modelling and simulation of a solar absorption cooling system for India

2006 ◽  
Vol 17 (3) ◽  
pp. 65-70 ◽  
Author(s):  
V Mittal ◽  
K S Kasana ◽  
N S Thakur
Keyword(s):  
Surface Area ◽  
Cooling System ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Reference Temperature ◽  
Inlet Temperature ◽  
Solar Absorption ◽  
Absorption Cooling ◽  
Solar Absorption Cooling ◽  
Absorption Cooling System

This paper presents modelling and simulation of a solar absorption cooling system. In this paper, the modelling of a solar-powered, single stage, absorption cooling system, using a flat plate collector and water–lithium bromide solution, is done. A computer program has been developed for the absorption system to simulate various cycle configurations with the help of various weather data for the village Bahal, District Bhiwani, Haryana, India. The effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling component are studied. The hot water inlet temperature is found to affect the surface area of some of the system components. Moreover the effect of the reference temperature which is the minimum allowable hot water inlet temperature on the fraction of total load met by non-purchased energy (FNP) and coefficient of performance (COP) is studied and it is found that high reference temperature increases the system COP and decreases the surface area of system components but lower reference temperature gives better results for FNP than high reference temperatures.

Experimental Study of Heating-Cooling Combined Ground Source Heat Pump System with Horizontal Ground Heat Exchanger

2011 ◽  
Vol 374-377 ◽  
pp. 398-404 ◽  
Author(s):  
Ying Ning Hu ◽  
Ban Jun Peng ◽  
Shan Shan Hu ◽  
Jun Lin
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Pump ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Ground Heat Exchanger ◽  
Pipe Length ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling

A hot-water and air-conditioning (HWAC) combined ground sourse heat pump(GSHP) system with horizontal ground heat exchanger self-designed and actualized was presented in this paper. The heat transfer performance for the heat exchanger of two different pipe arrangements, three layers and four layers, respectively, was compared. It showed that the heat exchange quantity per pipe length for the pipe arrangement of three layers and four layers are 18.0 W/m and 15.0 W/m. The coefficient of performance (COP) of unit and system could remain 4.8 and 4.2 as GSHP system for heating water, and the COP of heating and cooling combination are up to 8.5 and 7.5, respectively. The power consumption of hot-water in a whole year is 9.0 kwh/t. The economy and feasibility analysis on vertical and horizontal ground heat exchanger were made, which showed that the investment cost per heat exchange quantity of horizontal ground heat exchanger is 51.4% lower than that of the vertical ground heat exchanger, but the occupied area of the former is 7 times larger than the latter's.

scholarly journals Comparison of Transcritical CO2 and Conventional Refrigerant Heat Pump Water Heaters for Domestic Applications

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 479
Author(s):  
Ignacio Paniagua ◽  
Ángel Álvaro ◽  
Javier Martín ◽  
Celina Fernández ◽  
Rafael Carlier
Keyword(s):  
Heat Pump ◽  
Thermodynamic Cycle ◽  
Heat Pumps ◽  
Design Tool ◽  
Operating Conditions ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Ambient Conditions ◽  
Water Heater ◽  
Water Heaters

Although CO 2 as refrigerant is well known for having the lowest global warming potential (GWP), and commercial domestic heat pump water heater systems exist, its long expected wide spread use has not fully unfolded. Indeed, CO 2 poses some technological difficulties with respect to conventional refrigerants, but currently, these difficulties have been largely overcome. Numerous studies show that CO 2 heat pump water heaters can improve the coefficient of performance (COP) of conventional ones in the given conditions. In this study, the performances of transcritical CO 2 and R410A heat pump water heaters were compared for an integrated nearly zero-energy building (NZEB) application. The thermodynamic cycle of two commercial systems were modelled integrating experimental data, and these models were then used to analyse both heat pumps receiving and producing hot water at equal temperatures, operating at the same ambient temperature. Within the range of operation of the system, it is unclear which would achieve the better COP, as it depends critically on the conditions of operation, which in turn depend on the ambient conditions and especially on the actual use of the water. Technology changes on each side of the line of equal performance conditions of operation (EPOC), a useful design tool developed in the study. The transcritical CO 2 is more sensitive to operating conditions, and thus offers greater flexibility to the designer, as it allows improving performance by optimising the global system design.

Effect of TiO2/MO Nano-lubricant on Energy and Exergy Savings of an Air Conditioner using Blends of R22/R600a

2020 ◽  
Vol 17 (4) ◽  
pp. 8283-8297
Author(s):  
M.E. Abdur Razzaq ◽  
J. U. Ahamed ◽  
M.A. M. Hossain
Keyword(s):  
Energy Consumption ◽  
Power Consumption ◽  
Tio2 Nanoparticles ◽  
Volume Fraction ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Exergy Destruction ◽  
Nano Lubricant

This experimental study determines the energetic and exergetic performances of an air conditioner using blend of R22/R600a (60:40 by mass) for different volume fractions (0.1 %, 0.2 %, 0.3 %, and, 0.4 %) of TiO2 nanoparticles dispersed into mineral oil (MO). Energetic and exergetic parameters investigated in this experiment including power consumption, cooling effect, discharge pressure and temperature, coefficient of performance (COP), exergy destruction (irreversibility), irreversibility in the component, sustainability index (SI) and exergy efficiency at different operating conditions. The k-type thermocouples and pressure gauge were used to measure the temperature and pressure at different locations of the air conditioner. Thermodynamic characteristics of the refrigerant were collected using REFPROP 7. Results showed that the lowest power consumption and total exergy destruction were observed in the system with 0.4% volume fraction of TiO2 nanoparticles charge in the TiO2/MO lubricant with refrigerant blend; these values of energy consumption and total exergy destruction were 12.76 % and 7.5 % respectively, which is lower than R22/Polyol ester (POE) lubricant. The COP for the blend was increased by 6.5% to 8.3% compared to R22 and with nano-lubricant COP for the blend was increased by 17.9% to 19.9% compared to R22/POE. The air conditioner using blend charge with 0.4% TiO2/MO lubricant has the maximum COP and exergy efficiency among the selected nano-lubricants. These values of COP and exergy efficiency were 19.9 % and 35.07 % respectively, greater than that of R22/POE. Again, compressor discharge temperature was found to be decreased with the introduction of nano-lubricants compared to the original system, and the expectancy of compressor life may be extended with TiO2/MO nano-lubricant. Among the components, the compressor was found to be maximum exergy destroyer (at 60 %), followed by the condenser (at 25.4 %) and evaporator (at 13.3 %). Overall, the study found that refrigerant blend with nano-lubricant minimised the energy consumption and exergy destruction and the system operated safely with nano-lubricant without any system modification.

Life Cycle Cost for a Solar Heating and Cooling System

2009 ◽  
Author(s):  
Yin Hang ◽  
Ming Qu
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Cooling System ◽  
Heating System ◽  
Solar Heating ◽  
Hot Water ◽  
Solar Absorption ◽  
Heating And Cooling ◽  
Absorption Cooling ◽  
Solar Absorption Cooling

Solar absorption cooling has been an intriguing research subject since 1970. However, it is not widely applied because the first cost of the system is high, the commercial hot water absorption chiller is not mature, the site demonstration and evaluation are not adequate and the price of conventional fossil energy sources is relatively low. This paper investigates the commercialization potentials of solar absorption cooling and solar heating system by comparing the life cycle cost between it and the conventional electrical chiller cooling and gas-fired boiler heating system. A computational model has been programmed in the Engineering Equation Solver (EES) to analyze the economical performances of the two systems applied to a dedicated building. The model considers the cost of capital, installation, operation and maintenance, the discount rate, the fuel prices, and the inflation rates. The result of the model indicated that given the present fuel cost, the solar absorption cooling and heating system is not as economic as the conventional system especially when its size is small. However, according to the sensitivity analysis carried, the solar absorption cooling and heating system could compete with the conventional cooling and heating system when the electricity price and fuel inflation increase.

Modelling and Simulation of a Solar Single Effect Absorption Cooling System in Aspen Hysys®

2016 ◽  
Author(s):  
Erni S. Ramos ◽  
Guillermo E. Valencia ◽  
Adriana M. Jiménez ◽  
Marisol Osorio ◽  
Marley C. Vanegas
Keyword(s):  
Loss Rate ◽  
Exergy Efficiency ◽  
Exergy Loss ◽  
Coefficient Of Performance ◽  
Second Law ◽  
Total Solar Radiation ◽  
Steady State Condition ◽  
Aspen Hysys ◽  
Absorption Cooling ◽  
Single Effect

As an alternative to conventional vapor compression cooling systems, a thermodynamic analysis with the integration of Aspen Hysys® and MatLab® to a solar driven single effect LiBr - Water absorption cooling is conducted in this paper under meteorological conditions for Barranquilla in Colombia supplied with a solar captive system integrated by 15 flat plat solar collectors Barilla F22AR. First law and second law of thermodynamic are applied to system in order to calculate the thermodynamic states and exergy of each stream of the system, in addition to the Coefficient of performance and second law exergy efficiency of the chiller, and exergy loss rate for every component and the whole system. The influence of monthly variation of total solar irradiance on COP, exergy efficiency and exergy loss rate is evaluated in this study under steady state condition for each month of the year. The results of this study show a proportional relationship between heat loads calculated in each component and the heat flow supplied by the solar captive system to the generator, moreover the total solar radiation is directly related to the COP and inversely proportional exergy efficiency.

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