The vapor compression cycle (VCC) is useful for the removal
of heat through the region of low temperature to the high temperature
reservoir. The load variation in the system makes capable for the peak cooling
system. In case of standard vapor
compression cycle there are four major processes including compression,
condensation, expansion and evaporation (Jain, Neera; Alleyne,
Andrew G., 2011).
The coefficient of performance is basically efficiency metric for the first law
of thermodynamics. The optimization of vapor cycle performance was carried out
by using The Expert System for Thermodynamics (TEST) on the online webpage http://www.thermofluids.net/ .
The efficiency for the low and higher temperature
consideration is a function of temperature and the metric based analysis are
according to first law thermodynamics. The present work measures various
factors having effect on the efficiency of the vapor cycle. Two parameters are
selected for the optimization of the vapor cycle. The vapor compression cycle
is formulated by using vapor compression cycle. The evaluation begins with formulism
of appropriate functions (Jain & Alleyne,
2011).
Vapor cycle performance using test
The first step is to identify the objective function for the
working principle of life cycle, the second step is to formulate the equations
to deduce the problem solving strategies. The goal of project is optimization
of cycle efficiency or meaning of coefficient of performance for the
parameters. The evaluation process of vapor properties for the vapor cycle is
carried out by using a web Brower based program that is The Expert System for
Thermodynamics (TEST) (Diva-portal. org,
2011).
The Expert System for
Thermodynamics (TEST) is a web based services provided through the HTML pages
and provides equations, schematics, embedded Java applets, animations, and
thermodynamic and these functions are known as daemons . The general objective
of the Expert System for Thermodynamics (TEST) as a visual tool is to solve the
thermodynamic problems (Zietlow, 2014).
Figure 1: Online daemon selection
In case of Rankine cycle the analysis contains regenerative
cycle and reheating process. The heat pumps and the refrigerators works on the
basis of complex cycles of multistage (refrigerator-freezer) system (Peer. asee.
org, 2003).
The significant performance of the vapor compression cycle is due to saturation
temperature, effective temperature and coefficient of performance. The drop is
saturation temperature of condenser results in increase of heat transfer on the
surface area with increase in coefficient of performance (Jain & Alleyne,
2011).
The efficiency of mechanical devices provides information about ratio of input
and output performance. The typical values of efficiency for the mechanical
devices are mentioned below,
|
Mechanical
device
|
Efficiency
|
|
Turbine
|
80
% - 95 %
|
|
Pumps
and compressor
|
70 % - 85 %
|
|
Boiler
efficiency
|
90
%
|
In order to perform the measurement for the vapor cycle
performance by using the Expert System for Thermodynamics (TEST) the working
fluid was first considered for the flow. The variables were added for the state
of the fluid and the extended set of variables was according to the local
thermodynamic equilibrium. The complex material model is used for the phase
change fluid, the ideal gases are considered as intermediate variable and
composition is applied.
The temperature plot is given for the non-refrigerated
fluids and superimpose of inlet temperature is given. The outcome of the
analysis is to measurement of specific enthalpy and components of the systems.
The isothermal processes and the isentropic process are considered for the
performance of system. The isentropic process measured the component
performance and the heat exchanged in the process. The saturation line data was
obtained through the online calculation.
Conclusion of
Optimization on vapor cycle performance using TEST
The TEST analysis for the optimization of vapor cycle
performance is carried out by using freely accessible online source http://www.thermofluids.net/. The input
parameters for the heat cycle is provided to the TEST on the SDSU server. The output
curve of the analysis consisted of four processes was analyzed. The four cycles
includes compression, evaporation, condensation, and expansion.
References of Optimization on vapor cycle performance using test
Diva-portal.
org. (2011). Optimization of performance and assessment of material cost of the
refrigerator condenser. Retrieved from www.diva-portal.org:
http://www.diva-portal.org/smash/get/diva2:441222/ATTACHMENT01
Jain, N., & Alleyne, A. G. (2011). THERMODYNAMICS-BASED
OPTIMIZATION AND CONTROL OFVAPOR-COMPRESSION CYCLE OPERATION: CONTROL SYNTHESIS.
Proceedings of the ASME 2011 Dynamic Systems and Control Conference, 01(01),
01-08.
Jain, Neera; Alleyne, Andrew G. (2011). Thermodynamics-Based
Optimization and Control of Vapor-Compression Cycle Operation: Optimization
Criteria. American Control Conference, 01(01), 1352-1357.
Peer. asee. org. (2003). TEST - THE EXPERT SYSTEM FOR
THERMODYNAMICS. Retrieved from peer.asee.org:
https://peer.asee.org/test-the-expert-system-for-thermodynamics.pdf
Zietlow, D. C. (2014). Optimization of Vapor Compression Cycles.
American Society for Engineering Education, 01(01), 01-23.
