Volodymyr Voloshchuk: New Applications
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en-us2021 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemFri, 07 May 2021 15:27:42 GMTFri, 07 May 2021 15:27:42 GMTNew applications published by Volodymyr Voloshchukhttps://www.maplesoft.com/images/Application_center_hp.jpgVolodymyr Voloshchuk: New Applications
https://www.maplesoft.com/applications/author.aspx?mid=214609
Thermodynamic Calculations of Cascade Vapor Compression Refrigeration Cycle
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In the event that a high COP of a refrigeration cycle is of greater importance compared to other factors, it is possible to significantly increase the COP of a basic cycle through the use of a multistage vapor compression cycle. This is especially true when the pressure ratio between the heat rejection and heat absorption pressures is large 5 or more.
Multistaging involves one or more intermediate pressures between the heat rejection and heat absorption pressures, and a series of compressors operating between successive pressure intervals.
Cascade cycle is simply a chain of single stage vapor compression cycles operating in series, such that the condenser of a lower temperature cycle provides the heat input to the evaporator of the higher temperature cycle.<img src="https://www.maplesoft.com/view.aspx?si=154116/CascadeHP.png" alt="Thermodynamic Calculations of Cascade Vapor Compression Refrigeration Cycle" style="max-width: 25%;" align="left"/>In the event that a high COP of a refrigeration cycle is of greater importance compared to other factors, it is possible to significantly increase the COP of a basic cycle through the use of a multistage vapor compression cycle. This is especially true when the pressure ratio between the heat rejection and heat absorption pressures is large 5 or more.
Multistaging involves one or more intermediate pressures between the heat rejection and heat absorption pressures, and a series of compressors operating between successive pressure intervals.
Cascade cycle is simply a chain of single stage vapor compression cycles operating in series, such that the condenser of a lower temperature cycle provides the heat input to the evaporator of the higher temperature cycle.https://www.maplesoft.com/applications/view.aspx?SID=154116&ref=FeedTue, 07 Jun 2016 04:00:00 ZVolodymyr VoloshchukVolodymyr VoloshchukAdvanced Exergetic Analysis of Simple Vapor Compression Refrigeration Cycle
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An advanced exergetic analysis converts the most important limitations of the conventional analysis into strengths. An advanced analysis provides options to estimate (a) the real potential for improving the components (splitting the exergy destruction into unavoidable and avoidable parts); and (b) the mutual interdependencies among the exergy destructions within the components of a system (splitting the exergy destruction into endogenous and exogenous parts). Distinctions between avoidable and unavoidable exergy destruction on one side and endogenous and exogenous exergy destruction on the other side (with a further splitting of the exogenous exergy destruction) allow engineers to focus on the thermodynamic inefficiencies that can be avoided by simultaneously considering the interactions among system components. The avoidable endogenous and the avoidable exogenous exergy destructions provide the best guidance for improving the thermodynamic performance of energy conversion systems.
The drawbacks associated with the advanced exergetic analysis are the need for simulating some non-standard cycles (e.g., so-called hybrid cycles), the large number of required simulations and the associated engineering time.
Within this Maple-aided analysis, the potential for improving the thermodynamic efficiency of components and the overall vapor-compression refrigeration system as well as the interactions among components and their effect on the exergy destruction within each component can be estimated.<img src="https://www.maplesoft.com/view.aspx?si=154068/Vv-27-adv-ex-eng-SimpleRefrigerationCycle.png" alt="Advanced Exergetic Analysis of Simple Vapor Compression Refrigeration Cycle" style="max-width: 25%;" align="left"/>An advanced exergetic analysis converts the most important limitations of the conventional analysis into strengths. An advanced analysis provides options to estimate (a) the real potential for improving the components (splitting the exergy destruction into unavoidable and avoidable parts); and (b) the mutual interdependencies among the exergy destructions within the components of a system (splitting the exergy destruction into endogenous and exogenous parts). Distinctions between avoidable and unavoidable exergy destruction on one side and endogenous and exogenous exergy destruction on the other side (with a further splitting of the exogenous exergy destruction) allow engineers to focus on the thermodynamic inefficiencies that can be avoided by simultaneously considering the interactions among system components. The avoidable endogenous and the avoidable exogenous exergy destructions provide the best guidance for improving the thermodynamic performance of energy conversion systems.
The drawbacks associated with the advanced exergetic analysis are the need for simulating some non-standard cycles (e.g., so-called hybrid cycles), the large number of required simulations and the associated engineering time.
Within this Maple-aided analysis, the potential for improving the thermodynamic efficiency of components and the overall vapor-compression refrigeration system as well as the interactions among components and their effect on the exergy destruction within each component can be estimated.https://www.maplesoft.com/applications/view.aspx?SID=154068&ref=FeedWed, 30 Mar 2016 17:20:39 ZVolodymyr VoloshchukVolodymyr VoloshchukThermodynamic Calculations of Two-Stage Vapor Compression Refrigeration Cycle with Flash Chamber and Separate Vapor Mixing Intercooler
https://www.maplesoft.com/applications/view.aspx?SID=154065&ref=Feed
In the event that a high COP of a refrigeration cycle is of greater importance compared to other factors, it is possible to significantly increase the COP of a basic cycle through the use of a multistage vapor compression cycle. This is especially true when the pressure ratio between the heat rejection and heat absorption pressures is large 5 or more.
Multistaging involves one or more intermediate pressures between the heat rejection and heat absorption pressures, and a series of compressors operating between successive pressure intervals.
One type of multi-compressor vapor compression cycle includes a mixing chamber where saturated vapor from the flash chamber mixes with the vapor leaving the low pressure stage compressor. This vapor-mixing chamber acts as a regenerative intercooler since it cools the superheated vapor leaving the low-pressure stage compressor using lower temperature saturated workin fluid, mixing the two prior to the next stage of compression.
This type of refrigeration cycle is analysed in the following calculation.<img src="https://www.maplesoft.com/view.aspx?si=154065/Two-Stage_Vapor_Compression_Refrigeration_Cycle_with_Flash_Chamber_and_Separate_Vapor_Mixing_Intercooler.png" alt="Thermodynamic Calculations of Two-Stage Vapor Compression Refrigeration Cycle with Flash Chamber and Separate Vapor Mixing Intercooler" style="max-width: 25%;" align="left"/>In the event that a high COP of a refrigeration cycle is of greater importance compared to other factors, it is possible to significantly increase the COP of a basic cycle through the use of a multistage vapor compression cycle. This is especially true when the pressure ratio between the heat rejection and heat absorption pressures is large 5 or more.
Multistaging involves one or more intermediate pressures between the heat rejection and heat absorption pressures, and a series of compressors operating between successive pressure intervals.
One type of multi-compressor vapor compression cycle includes a mixing chamber where saturated vapor from the flash chamber mixes with the vapor leaving the low pressure stage compressor. This vapor-mixing chamber acts as a regenerative intercooler since it cools the superheated vapor leaving the low-pressure stage compressor using lower temperature saturated workin fluid, mixing the two prior to the next stage of compression.
This type of refrigeration cycle is analysed in the following calculation.https://www.maplesoft.com/applications/view.aspx?SID=154065&ref=FeedMon, 21 Mar 2016 04:00:00 ZVolodymyr VoloshchukVolodymyr Voloshchuk