Pub Date : 2020-01-01DOI: 10.17586/1606-4313-2020-19-3-21-26
S. Muraveinikov, A. Sulin, I. V. Baranov, T. Ryabova
evaluation of active heat exchangers. The technique is designed to assess the energy characteristics of active utilizers under conditions that differ from the passport values. The influence of deviation of such operational factors as air consumption, outdoor temperature in front of the utilizer, the temperature and humidity of the exhaust air is considered. The method takes into account the operating mode involving the heating of the external air before being fed into the room without affecting the air-cooling mode in the warm season. Coefficients of renewability and economic efficiency are proposed as criteria for comparing active and passive heat recovery devices. The proposed criteria make it possible to evaluate the efficiency of using recycling systems both in energy and in financial terms.
{"title":"Evaluation technique for the efficiency of the exhaust air heat recovery systems","authors":"S. Muraveinikov, A. Sulin, I. V. Baranov, T. Ryabova","doi":"10.17586/1606-4313-2020-19-3-21-26","DOIUrl":"https://doi.org/10.17586/1606-4313-2020-19-3-21-26","url":null,"abstract":"evaluation of active heat exchangers. The technique is designed to assess the energy characteristics of active utilizers under conditions that differ from the passport values. The influence of deviation of such operational factors as air consumption, outdoor temperature in front of the utilizer, the temperature and humidity of the exhaust air is considered. The method takes into account the operating mode involving the heating of the external air before being fed into the room without affecting the air-cooling mode in the warm season. Coefficients of renewability and economic efficiency are proposed as criteria for comparing active and passive heat recovery devices. The proposed criteria make it possible to evaluate the efficiency of using recycling systems both in energy and in financial terms.","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114152801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2022-21-2-56-60
T. I. Fomicheva, E. V. Koluzhnikova, P. Gunkova
Avocado and pumpkin seed oils have different origin and methods of production and are characterized by similar content. The purpose of the study is the comparison of the fatty acids composition in order to evaluate their advantages and disadvantages as well as beneficial qualities of their usage as biologically active additives and a cosmetic ingredient. The oils are characterized by a high content of fatty acids of various types, both saturated and unsaturated. In the article the overview of information about avocado and pumpkin origin and production based on literary sources is included; the composition of avocado and pumpkin oils is described. The chromatographic method of analysis allows to evaluate the quantitative ratios of the components. The content of stearic, palmitic, and myristic (fatty) acids was determined to be two times higher in pumpkin seed oil compared to avocado oil, it means the advantages of avocado oil as a low-calorie product. The analysis revealed especially high content of the essential unsaturated fatty acids: in pumpkin seed oil it is 80%, in avocado oil - 87%. Therefore, these oils show the expediency of using as a therapeutic agent for external and internal use particularly to reduce the risk of cardiovascular diseases.
{"title":"The avocado oil and pumpkin seed oil as a source of fatty acids","authors":"T. I. Fomicheva, E. V. Koluzhnikova, P. Gunkova","doi":"10.17586/1606-4313-2022-21-2-56-60","DOIUrl":"https://doi.org/10.17586/1606-4313-2022-21-2-56-60","url":null,"abstract":"Avocado and pumpkin seed oils have different origin and methods of production and are characterized by similar content. The purpose of the study is the comparison of the fatty acids composition in order to evaluate their advantages and disadvantages as well as beneficial qualities of their usage as biologically active additives and a cosmetic ingredient. The oils are characterized by a high content of fatty acids of various types, both saturated and unsaturated. In the article the overview of information about avocado and pumpkin origin and production based on literary sources is included; the composition of avocado and pumpkin oils is described. The chromatographic method of analysis allows to evaluate the quantitative ratios of the components. The content of stearic, palmitic, and myristic (fatty) acids was determined to be two times higher in pumpkin seed oil compared to avocado oil, it means the advantages of avocado oil as a low-calorie product. The analysis revealed especially high content of the essential unsaturated fatty acids: in pumpkin seed oil it is 80%, in avocado oil - 87%. Therefore, these oils show the expediency of using as a therapeutic agent for external and internal use particularly to reduce the risk of cardiovascular diseases.","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"378 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115172607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2020-19-3-91-99
R. Deeb, D. Sidenkov
Flow and heat transfer from a single drop-shaped and circular tubes in crossflow is studied numerically for the Reynolds numbers varying from 1.5·10 3 to 26.5·10 3 . These tubes have axis ratios of L/D = 1, 1.5, 2, 2.5, 3, 3.5, and 4, when L/D = 1, the tube is circular. The distribution of local coefficients of heat transfer α, pressure C p , and friction C f over a half of the tube surface is presented. The maximum value of C f gradually increases with the increase of L/D. Simulated results agree well with those available in the literature. Correlations of the average Nusselt number and a friction factor in terms of the Reynolds numbers and axis ratios for the studied tubes were proposed. Drop-shaped tubes have a lower pumping power to provide the same heat transfer compared to a circular one under the same operating conditions. The thermo-hydrodynamic characteristics of the drop-shaped tube with L/D = 4 are better as compared to other studied tubes.
{"title":"Numerical investigation of heat transfer and aerodynamics of single drop-shaped tubes","authors":"R. Deeb, D. Sidenkov","doi":"10.17586/1606-4313-2020-19-3-91-99","DOIUrl":"https://doi.org/10.17586/1606-4313-2020-19-3-91-99","url":null,"abstract":"Flow and heat transfer from a single drop-shaped and circular tubes in crossflow is studied numerically for the Reynolds numbers varying from 1.5·10 3 to 26.5·10 3 . These tubes have axis ratios of L/D = 1, 1.5, 2, 2.5, 3, 3.5, and 4, when L/D = 1, the tube is circular. The distribution of local coefficients of heat transfer α, pressure C p , and friction C f over a half of the tube surface is presented. The maximum value of C f gradually increases with the increase of L/D. Simulated results agree well with those available in the literature. Correlations of the average Nusselt number and a friction factor in terms of the Reynolds numbers and axis ratios for the studied tubes were proposed. Drop-shaped tubes have a lower pumping power to provide the same heat transfer compared to a circular one under the same operating conditions. The thermo-hydrodynamic characteristics of the drop-shaped tube with L/D = 4 are better as compared to other studied tubes.","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117246202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2022-21-2-21-26
S. Vizgalov, I. Sharapov, I. Khisameev
A system for accumulating generated electricity based on cryogenic technologies is considered – by liquefying air, storing it, followed by regasification and expansion in turbogenerators (LAES-system). This direction is quite innovative in this application. The review of works in this direction is carried out. At present, the main practical cycle for the purpose is the high-pressure cycle with liquid air cold recovery and direct flow throttling after cooling. A scheme of a medium pressure thermody-namic cycle with a turboexpander for a part of the flow is presented, as well as a method for its cal-culation. The calculations were carried out both with the use of the cold of the expanded flow and without taking it into account. The results of the calculations are presented in the form of graphic characteristics of the cycle as a function of the temperature at the expander extraction point and the pressure of the direct air flow. The characteristics were analyzed and conclusions about the applica-bility of this cycle were drawn.
{"title":"Systems of electricity accumulating based on cryogenic technologies of air liquification","authors":"S. Vizgalov, I. Sharapov, I. Khisameev","doi":"10.17586/1606-4313-2022-21-2-21-26","DOIUrl":"https://doi.org/10.17586/1606-4313-2022-21-2-21-26","url":null,"abstract":"A system for accumulating generated electricity based on cryogenic technologies is considered – by liquefying air, storing it, followed by regasification and expansion in turbogenerators (LAES-system). This direction is quite innovative in this application. The review of works in this direction is carried out. At present, the main practical cycle for the purpose is the high-pressure cycle with liquid air cold recovery and direct flow throttling after cooling. A scheme of a medium pressure thermody-namic cycle with a turboexpander for a part of the flow is presented, as well as a method for its cal-culation. The calculations were carried out both with the use of the cold of the expanded flow and without taking it into account. The results of the calculations are presented in the form of graphic characteristics of the cycle as a function of the temperature at the expander extraction point and the pressure of the direct air flow. The characteristics were analyzed and conclusions about the applica-bility of this cycle were drawn.","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"198 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121082807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2022-21-3-39-48
M. Alshevskaya, O. Anistratova, A.A. Kochina
{"title":"Technological peculiarities of developing a plant product with the use of Streptococcus Salivarius Subsp. Thermophilus and Lactobacillus Delbrueckii Subsp. Bulgaricus microorganisms.","authors":"M. Alshevskaya, O. Anistratova, A.A. Kochina","doi":"10.17586/1606-4313-2022-21-3-39-48","DOIUrl":"https://doi.org/10.17586/1606-4313-2022-21-3-39-48","url":null,"abstract":"","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123285924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2019-18-3-51-58
A. S. Kulikova, I. M. Titova
Соль в качестве усилителя вкуса улучшает органолептические свойства продукции, но в тоже время повышенное потребление соли негативно сказывается на здоровье человека. Проведен анализ возможности замены натрия хлорида на другие вещества, обеспечивающие соленый вкус. Выдвинута гипотеза о влияние компонентов экстракта зеленого чая на восприятие соленого вкуса в рыбных полуфабрикатах. Разработана технология и созданы модельные образцы рыбного полуфабриката. В качестве основного сырья был использован рыбный фарш из трески. Экстракт чая был получен настаиванием зеленого китайского чая и воды в соотношении 1:100, 2:100, 3:100, 5:100. Исследование проводили на 15 модельных образцах: два контроля, в тринадцати образцах массовая доля соли, после ее внесения, составляла 1,2±0,2 %. Образцы подверглись кулинарной обработке в идентичных условиях — 15 мин при t = 180 оС. Определение ощущаемого уровня соли в образцах проводили эксперты-дегустаторы. Диапазон оценки уровня солености варьировался от 0 % до 3,5 %. Результаты оценки экспертов позволили выявить определенную тенденцию — ощущение соли увеличивается с повышением процента содержания чая. Для количественной оценки степени согласия ответов экспертов был проведен анализ согласованности с использованием коэффициента конкордации. Полученный коэффициент (0,69) характеризует среднюю степень согласованности мнений экспертов. Полученные результаты легли в основу расчетов регрессионно-корреляционного анализа, с помощью которого была установлена сила взаимосвязи данных — ответов экспертов по ощущению соли и концентрации экстракта. Проведен анализ определения массовой доли поваренной соли во всех приготовленных образцах с экстрактом зеленого чая, который доказал, что компоненты чая не влияют на количественный уровень содержания соли (в среднем 1,47 %). Сделан вывод о влиянии водного экстракта зеленого чая на восприятие солености в готовом продукте. Ключевые слова: рыбный полуфабрикат, соль, водный экстракт зеленого чая.
{"title":"Evaluation of the synergistic effect of green tea water extract on the perception of the salinity in fish semi-finished product","authors":"A. S. Kulikova, I. M. Titova","doi":"10.17586/1606-4313-2019-18-3-51-58","DOIUrl":"https://doi.org/10.17586/1606-4313-2019-18-3-51-58","url":null,"abstract":"Соль в качестве усилителя вкуса улучшает органолептические свойства продукции, но в тоже время повышенное потребление соли негативно сказывается на здоровье человека. Проведен анализ возможности замены натрия хлорида на другие вещества, обеспечивающие соленый вкус. Выдвинута гипотеза о влияние компонентов экстракта зеленого чая на восприятие соленого вкуса в рыбных полуфабрикатах. Разработана технология и созданы модельные образцы рыбного полуфабриката. В качестве основного сырья был использован рыбный фарш из трески. Экстракт чая был получен настаиванием зеленого китайского чая и воды в соотношении 1:100, 2:100, 3:100, 5:100. Исследование проводили на 15 модельных образцах: два контроля, в тринадцати образцах массовая доля соли, после ее внесения, составляла 1,2±0,2 %. Образцы подверглись кулинарной обработке в идентичных условиях — 15 мин при t = 180 оС. Определение ощущаемого уровня соли в образцах проводили эксперты-дегустаторы. Диапазон оценки уровня солености варьировался от 0 % до 3,5 %. Результаты оценки экспертов позволили выявить определенную тенденцию — ощущение соли увеличивается с повышением процента содержания чая. Для количественной оценки степени согласия ответов экспертов был проведен анализ согласованности с использованием коэффициента конкордации. Полученный коэффициент (0,69) характеризует среднюю степень согласованности мнений экспертов. Полученные результаты легли в основу расчетов регрессионно-корреляционного анализа, с помощью которого была установлена сила взаимосвязи данных — ответов экспертов по ощущению соли и концентрации экстракта. Проведен анализ определения массовой доли поваренной соли во всех приготовленных образцах с экстрактом зеленого чая, который доказал, что компоненты чая не влияют на количественный уровень содержания соли (в среднем 1,47 %). Сделан вывод о влиянии водного экстракта зеленого чая на восприятие солености в готовом продукте. Ключевые слова: рыбный полуфабрикат, соль, водный экстракт зеленого чая.","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"69 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125382632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2022-21-3-27-38
E. A. Bazhenov, L. Baydalinova, T. Grimm
{"title":"Study of an enzyme preparation from the digestive organs of freshwater brook trout","authors":"E. A. Bazhenov, L. Baydalinova, T. Grimm","doi":"10.17586/1606-4313-2022-21-3-27-38","DOIUrl":"https://doi.org/10.17586/1606-4313-2022-21-3-27-38","url":null,"abstract":"","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125590799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2022-21-4-45-51
M. Kukin, M. Kostyuchenko, M. Nutchina, O. Parakhina
{"title":"Development of calibration models in the spectral range from 1400 to 2500 nm to determine the mass fraction of fat, sugar and moisture in bakery products by the NIR method","authors":"M. Kukin, M. Kostyuchenko, M. Nutchina, O. Parakhina","doi":"10.17586/1606-4313-2022-21-4-45-51","DOIUrl":"https://doi.org/10.17586/1606-4313-2022-21-4-45-51","url":null,"abstract":"","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122300731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2019-18-4-64-70
V. L. Lazarev, V. Gorokhov, D. Vlasov
The paper deals with the development of approaches and mathematical models for predicting and organizing the production of sausage products. A systematic approach to the synthesis of models to describe the dependence of the performance of the main types of equipment — units of chamber and tunnel types — on production and technological factors is presented. The approach is based on the principles of unification and typification of models. The methodology of obtaining the schedule of production for the enterprise using different schemes and operation modes for various types of equipment is described. With the use of the above approach and a set of standard unified models it is possible to predict and optimize production in different situations. This creates the conditions for timely supply of products to consumers and improves the efficiency of the forwarding service. Monitoring methods and technologies are programmable and can be integrated into an enterprise management system. The proposed approach can also be used in solving similar problems in other industries where such equipment is used.
{"title":"Forecasting and management of sausage production on the basis of unified models","authors":"V. L. Lazarev, V. Gorokhov, D. Vlasov","doi":"10.17586/1606-4313-2019-18-4-64-70","DOIUrl":"https://doi.org/10.17586/1606-4313-2019-18-4-64-70","url":null,"abstract":"The paper deals with the development of approaches and mathematical models for predicting and organizing the production of sausage products. A systematic approach to the synthesis of models to describe the dependence of the performance of the main types of equipment — units of chamber and tunnel types — on production and technological factors is presented. The approach is based on the principles of unification and typification of models. The methodology of obtaining the schedule of production for the enterprise using different schemes and operation modes for various types of equipment is described. With the use of the above approach and a set of standard unified models it is possible to predict and optimize production in different situations. This creates the conditions for timely supply of products to consumers and improves the efficiency of the forwarding service. Monitoring methods and technologies are programmable and can be integrated into an enterprise management system. The proposed approach can also be used in solving similar problems in other industries where such equipment is used.","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114243236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17586/1606-4313-2020-19-4-3-11
A. Yablokov, Y. Kozhukhov, N. Sadovsky
The results of numerical analysis for the influence of the equivalent sand roughness of compressor impeller on the characteristics of centrifugal compressor low-emission intermediate type stage are presented . Low-emission stags are widely used in high-pressure compressors as the final stages . Compressors of the type are used for natural gas injection as well as in the production of methanol , ammonia , high pressure polyethylene and other processes . Operating ef ficiency of low-emission stages is lower than the one of medium - tificatio n of the mathematical model for the flow path is made and the results of low-emission stage tests are presented . In the second part of the article a modelling of a viscous gas flow under various values of equivalent sand roughness k s for all internal surfaces of the impeller is carried out . N 2 perfect gas is used as a medium for modelling . The operating pressure at the stage inlet is four atmospheres . The characteristics of the stage for four various values of k s are obtained and the losses in the impeller are evaluated . When the values of k s increase a uniform decrease of polytropic pressure head and efficiency coefficient are not observed for all characteristic of the low-emission stage . The characteristics are much lower in the high flow zones and do not differ greatly at minimum flow. The dependence of internal head coefficie nt on k s is low . of design head coefficient on conditional discharge coefficient. k s for the internal surfaces of the 2·10 -6 m impeller
{"title":"The influence of the equivalent sand roughness of compressor impeller on the characteristics of centrifugal compressor low-emission stage. a numerical analysis","authors":"A. Yablokov, Y. Kozhukhov, N. Sadovsky","doi":"10.17586/1606-4313-2020-19-4-3-11","DOIUrl":"https://doi.org/10.17586/1606-4313-2020-19-4-3-11","url":null,"abstract":"The results of numerical analysis for the influence of the equivalent sand roughness of compressor impeller on the characteristics of centrifugal compressor low-emission intermediate type stage are presented . Low-emission stags are widely used in high-pressure compressors as the final stages . Compressors of the type are used for natural gas injection as well as in the production of methanol , ammonia , high pressure polyethylene and other processes . Operating ef ficiency of low-emission stages is lower than the one of medium - tificatio n of the mathematical model for the flow path is made and the results of low-emission stage tests are presented . In the second part of the article a modelling of a viscous gas flow under various values of equivalent sand roughness k s for all internal surfaces of the impeller is carried out . N 2 perfect gas is used as a medium for modelling . The operating pressure at the stage inlet is four atmospheres . The characteristics of the stage for four various values of k s are obtained and the losses in the impeller are evaluated . When the values of k s increase a uniform decrease of polytropic pressure head and efficiency coefficient are not observed for all characteristic of the low-emission stage . The characteristics are much lower in the high flow zones and do not differ greatly at minimum flow. The dependence of internal head coefficie nt on k s is low . of design head coefficient on conditional discharge coefficient. k s for the internal surfaces of the 2·10 -6 m impeller","PeriodicalId":148431,"journal":{"name":"Journal International Academy of Refrigeration","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129245286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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