Thermoeconomic Indicators of Air Conditioning in a River Ship to Change the Configuration of Their Thermal Insulation

2014 ◽  
Author(s):  
J. Fajardo ◽  
B. Sarria ◽  
M. Alvarez Guerra
Keyword(s):  
System Performance ◽  
Heat Load ◽  
Air Conditioning ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Cooling Load ◽  
Air Conditioning System ◽  
Object Of Study ◽  
The Cost

This work has as object of study the energy of a river ship air conditioning system performance, using fiberglass, polyurethane or rockwool as insulation. Thermoeconomics Indicators based on second law of thermodynamics which take into account the quality of the energy and the cost of the exergy were used for research. It was observed that: (i) by increasing the thickness of the insulation the irreversibilities decreased, (ii) increases in the destroyed exergy increased generation of cooling load costs and (iii) costs per unit of exergy of heat load and area for the generation of cooling load and for investment in exergetic insulation, were minors for polyurethane.

EXERGY ANALYSIS OF THE PERFORMANCE OF A VARIABLE REFRIGERANT FLOW (VRF) AIR CONDITIONING SYSTEM

2011 ◽  
Vol 19 (01) ◽  
pp. 57-68 ◽  
Author(s):  
MIGUEL PADILLA
Keyword(s):  
System Performance ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Control Volume ◽  
Hvac Systems ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Air Conditioning System ◽  
Operational Conditions ◽  
Highly Sensitive

Commercial multiple evaporators variable refrigerant flow (VRF) HVAC systems present many advantages such as being energy saving and the capability of adjusting refrigerant mass flow rate according to the change of high rises occurrence. This paper deals with an experimental control volume exergy analysis in a VRF air conditioning system. The experimental results show that the brunt of the total exergy destroyed in the whole system occurs in the outdoor unit, where the exergy destroyed in the condenser is more important. The values of coefficient of performance (COP) obtained for the tests increase as the system reaches operational conditions imposed in every indoor unit zone. The VRF system analyzed is highly sensitive to the action of the constant speed compressor. The use of an inverter compressor improves the system performance by adjusting the power consumption according to the cooling load in the evaporators.

scholarly journals ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ СИСТЕМИ КОМБІНОВАНОГО ТИПУ

2019 ◽  
pp. 9-14
Author(s):  
Євген Іванович Трушляков ◽  
Андрій Миколайович Радченко ◽  
Микола Іванович Радченко ◽  
Сергій Анатолійович Кантор ◽  
Веніамін Сергійович Ткаченко
Keyword(s):  
Heat Load ◽  
Air Conditioning ◽  
Rational Design ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Energetic Efficiency ◽  
Cooling Load ◽  
Air Conditioner ◽  
Outdoor Air ◽  
Air Conditioning System

One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems is to provide the operation of refrigeration compressors in nominal or close to nominal modes by choosing rational design cooling loads (cooling capacities) and their distribution according to a cooling load behaviour within the overall design (installed) cooling load band to match current changeable climatic conditions and provide close to maximum annual cooling capacity generation according to cooling duties. The direction of increasing the efficiency of outdoor air conditioning in combined central-local type systems by rationally distributing the heat load - cooling capacity of the central air conditioner into zones of variable heat load in accordance with current climatic conditions and its relatively stable value, i.e. cooling capacity required for further air cooling at the entrance to the indoor recirculation air conditioning system is justified. By comparing the values of the excessive production of cold and its deficit within every 3 days for a rational design heat load of the air conditioning system (cooling capacity of the installed refrigeration machine), which provides close to maximum annual production of cold, and the corresponding values of the excess and deficit of cooling capacity in accordance with current climatic conditions during July substantiated the feasibility of accumulating the excess of cooling capacity of a central air conditioner at low current loads and its use for covering cooling deficit at elevated heat loads through pre-cooling the outdoor air. It is developed a scheme of a combined central-local air conditioning system, which includes the subsystems for the outdoor air conditioning in a central air conditioner and the local indoor recirculated air conditioning.

scholarly journals Application of the Second Law of Thermodynamics in Brazilian Residential Appliances towards a Rational Use of Energy

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 616 ◽  
Author(s):  
Carlos Eduardo Keutenedjian Mady ◽  
Clara Reis Pinto ◽  
Marina Torelli Reis Martins Pereira
Keyword(s):  
Energy Efficiency ◽  
Natural Resources ◽  
Air Conditioning ◽  
Second Law Of Thermodynamics ◽  
Exergy Efficiency ◽  
Second Law ◽  
Vapor Compression ◽  
Energy Matrix ◽  
Additional Information

This article proposes the utilization of the concepts of destroyed exergy and exergy efficiency for equipment and process performance indicators that are related to the current energy planning scenario in Brazil, more specifically with energy-efficiency labelling. Several indicators associated with these concepts are discussed, including one national program that is based on labeling the energy efficiency of several residential, commercial and industrial appliances. The grades are indicated in the equipment using values from A to G. This labeling system is useful for discriminating similar technologies used for the same function; nevertheless produced by different enterprises. For this complementary analysis, two types of refrigeration methods were compared, absorption and vapor compression; however, these energy indexes alone are not sufficient parameters to select among these two technologies, because their performance indexes definition are different. To address this, our research considers the second law of thermodynamics through exergy analysis as a proper sub-index to obtain a systematic comparison between these various indicators. It is significant to highlight that seldom research studies addressed to this problem so explicitly, in an actual governmental working solution, aiming at discussing to the society the advantage of the usage of the “quality of the energy” as a complementary index to governmental and personal choices. Results indicate that it is possible to use the destroyed exergy and exergy efficiency to help select the technology that better utilizes natural resources, considering the energy matrix of the country. Appliances for water heating and air conditioning were compared from energy and exergy viewpoint, where the last gave additional information about the quality of energy conversion process, giving a completely different trend from the energy analysis alone, without the necessity to think about the energy matrix. Later this issue is addressed from both points of view. Future studies may suggest an exergy based index. The energy efficiency suggests that electrical shower (values higher than 95%) are better than gas water heaters (83% ) in using natural resources, whereas the exergy efficiency shares similar magnitudes (about 3%). A related pattern is shown for the theoretical air conditioning systems. The vapor compression systems have an energy index higher than 3, and absorption systems lower than 1. For these circumstances, the exergy efficiency shows figures nearby 30%.

Thermodynamic Analysis of a Multi-Fueled Single Cylinder SI Engine

2011 ◽  
Author(s):  
M. Z. Haq ◽  
M. R. Mohiuddin
Keyword(s):  
Thermodynamic Analysis ◽  
Chemical Properties ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Si Engine ◽  
Gaseous Species ◽  
Single Cylinder ◽  
Engine Cylinder ◽  
Si Engines

The paper presents a thermodynamic analysis of a single cylinder four-stroke spark-ignition (SI) engine fuelled by four fuels namely iso-octane, methane, methanol and hydrogen. In SI engines, due to phenomena like ignition delay and finite flame speed manifested by the fuels, the heat addition process is not instantaneous, and hence ‘Weibe function’ is used to address the realistic heat release scenario of the engine. Empirical correlations are used to predict the heat loss from the engine cylinder. Physical states and chemical properties of gaseous species present inside the cylinder are determined using first and second law of thermodynamics, chemical kinetics, JANAF thermodynamic data-base and NASA polynomials. The model is implemented in FORTRAN 95 using standard numerical routines and some simulation results are validated against data available in literature. The second law of thermodynamics is applied to estimate the change of exergy i.e. the work potential or quality of the in-cylinder mixture undergoing various phases to complete the cycle. Results indicate that, around 4 to 24% of exergy initially possessed by the in-cylinder mixture is reduced during combustion and about 26 to 42% is left unused and exhausted to the atmosphere.

scholarly journals Performance analysis of retrofit R410a refrigerant with R32 refrigerant on a split air conditioner

2021 ◽  
Vol 2 (1) ◽  
pp. 1-4
Author(s):  
I Nengah Ardita ◽  
◽  
I Gusti Agung Bagus Wirajati ◽  
I Dewa Made Susila ◽  
Sudirman Sudirman ◽  
...  
Keyword(s):  
System Performance ◽  
Air Conditioning ◽  
Quantitative Description ◽  
Air Conditioner ◽  
Experimental Equipment ◽  
Evaporation Heat ◽  
Before And After ◽  
Common Group ◽  
The Cost ◽  
Design And Manufacture

Split air conditioning (AC) is the most widely used in the community for both commercial and domestic utilities. At the present refrigerant which used in Split AC is mostly common group of HFCs, such as R410a. R410a is a zeotropic refrigerant and if there is a leak in the system, it cannot be added this refrigerant. This will increase the cost of maintenance. The aims of this research is to investigate the retrofit of R410a with R32 on the Split AC system. The R32 is chosen because it has higher latent evaporation heat at the same temperature and has less effect on global warming. The refrigeration effect, the power consumption and the system performance are the main three quantities that want to be examined in this research which are observed before and after retrofit. Experimental investigation conducted during this research, including design and manufacture of experimental equipment, calibration and tools installment, collecting the experimental data and analysis by quantitative description method before and after retrofit. The results informed that cooling effect increased during the research, but the COP system has a slight decrease about 4%. R32 refrigerant is quite feasible as a retrofit refrigerant to R410a refrigerant.

scholarly journals RESEARCH OF QUALITY FORMATION OF TRANSPORT SERVICES BY PASSENGER TRANSPORT ENTERPRISES OF EU

2021 ◽  
Vol 49 (2) ◽  
pp. 122-130
Author(s):  
Nazarenko I ◽  
Keyword(s):  
Quality Criteria ◽  
Modern Society ◽  
Enterprise Management ◽  
Passenger Transport ◽  
Global Trends ◽  
Transport Services ◽  
Object Of Study ◽  
The Cost ◽  
Transport Complex

The article examines the processes, criteria and factors to ensure the quality of passenger transport services. Object of study - processes to ensure the quality of passenger transport services in the context of European integration of Ukraine. Purpose - a study of the world experience in the formation of the concept of quality of transport services, summarizing the main factors that affect the quality of transport services, as well as the main criteria affecting the qualitative characteristics of the services of the transport. Method study - generalization of fundamental works of Ukrainian and foreign scientists of economists is in the internal checking system, dialectical going, fundamental positions of economic theory, system-logical approach near research of the economic phenomena and processes. Satisfaction the needs of society and economy of passenger transport services depends on the quality and timeliness of those services. Questions of quality passenger transport services are interested in users of transport services, companies providing them. However, the requirements and the basic criteria for assessing the quality they are different. If the passenger transport enterprise interested in providing their services with minimal effort and money, the service users in their assessment pay attention not only on the cost of services, but also on transport safety, comfort, delivery time, etc.. The quality of the transport concept of integrated services, which is constantly being developed and improved. Global trends show that the quality of transport services must ensure the needs and expectations of consumers. Accordingly, it is increasing the importance of defining the qualities that affect the quality of service. Given the transient and dynamic nature of modern society and the lifestyle of the main consumers of the services the system factors and quality criteria must be flexible and dynamic to meet the industry's competitiveness on the European market of services. Awareness of the main criteria for assessing the quality of services will help to identify potential strengths and weaknesses. This will help improve not only the quality but also the process of enterprise management, industry, improve customer satisfaction of services received, will increase competitiveness. The results of the article can be inculcated in-process services of enterprises of a transport complex. KEYWORDS: QUALITY, TRANSPORT SERVICE. CRITERIA of QUALITY, TRANSPORT.

scholarly journals Energy in Growth Accounting and the Aggregation of Capital and Output

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Reiner Kümmel ◽  
Dietmar Lindenberger
Keyword(s):  
Time Series ◽  
Work Performance ◽  
Value Added ◽  
Second Law Of Thermodynamics ◽  
Production Functions ◽  
Growth Accounting ◽  
Second Law ◽  
Industrial Countries ◽  
The Cost ◽  
Energy Dependent

Abstract We review the physical aggregation of value added and capital in terms of work performance and information processing and its relation to the deflated monetary time series of output and capital. In growth accounting it complements the time series of labor and energy, measured in hours worked per year and kilowatt-hours consumed per year, respectively. This aggregation is the conceptual basis on which those energy-dependent production functions have been constructed that reproduce economic growth of major industrial countries in the 20th century with small residuals and output elasticities that are for energy much larger and for labor much smaller than the cost shares of these factors. Accounting for growth in such a way, which deviates from that of mainstream economics, may serve as a first step towards integrating the First and the Second Law of Thermodynamics into economics.

Exergy Analysis on a Split-Type Conditioner Using Ejector as an Expansion Device

2014 ◽  
Vol 699 ◽  
pp. 828-833 ◽  
Author(s):  
Sumeru ◽  
Markus ◽  
Farid Nasir Ani ◽  
Henry Nasution
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Energy Savings ◽  
Air Conditioner ◽  
Total Energy Consumption ◽  
Air Conditioning System ◽  
Air Conditioners ◽  
Exergy Losses

Air conditioning system consumes approximately 50% of the total energy consumption of buildings. Split-type air conditioner is the most widely used in residential and commercial buildings. As a result, enhancement on the performance of the air conditioners will yield a significant energy savings. The use of ejector as an expansion device on the split-type air conditioners is one method to increase the system performance. Exergy analysis on a split-type air conditioner uses an ejector as an expansion device at room and outdoor temperatures of 24 °C and 34 °C, respectively, yielded the percentage of exergy reduction up to 40.6%. Also, the exergy losses on in the compressor had the highest impact on the performance improvement of the split-type air conditioner.

First and second law analyses of the developed solar-desiccant air-conditioning system (SDACS) operation during the summer day

2013 ◽  
Vol 60 ◽  
pp. 239-251 ◽  
Author(s):  
Napoleon Enteria ◽  
Hiroshi Yoshino ◽  
Rie Takaki ◽  
Hiroshi Yonekura ◽  
Akira Satake ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Second Law ◽  
Air Conditioning System
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