This paper deals with thermodynamic and thermokinetic properties of R404A refrigerant, which is one of the more commonly used in mine air compression refrigerators. Knowledge of these parameters is essential to analyze performance of such refrigeration equipment, to design it, or to estimate efficiency of air refrigerators using various refrigerants. These properties can be defined using 27 simple computational formulas, contained in 4 tables (Tables 2, 6, 10 and 12). The relationships determining thermodynamic and thermokinetic parameters of R404A occur in saturated liquid region, dry saturated vapor region, superheated vapor region and supercooled liquid region. The developed relationships were subjected to statistical verification. For this purpose, correlation coefficients, coefficients of determination, as well as absolute and relative deviations were determined by comparing results of the calculations with the corresponding results obtained by REFPROP 7 (Lemmon et al., 2002). Results of verification are contained in Tables 14 and 15.
本文研究了矿井空气压缩制冷机中常用的R404A制冷剂的热力学和热力学性质。了解这些参数对于分析此类制冷设备的性能、设计制冷设备或评估使用各种制冷剂的空气制冷机的效率至关重要。这些属性可以使用27个简单的计算公式来定义，这些公式包含在4个表中(表2、6、10和12)。决定R404A热力学和热力学参数的关系发生在饱和液体区、干燥饱和蒸汽区、过热蒸汽区和过冷液体区。发展的关系受到统计验证。为此，通过将计算结果与REFPROP 7得到的相应结果进行比较，确定相关系数、决定系数以及绝对和相对偏差(Lemmon et al.， 2002)。核查结果载于表14和表15。
{"title":"FUNCTIONAL DEPENDENCIES OF THERMODYNAMIC AND THERMOKINETIC PARAMETERS OF REFRIGERANTS USED IN MINE AIR REFRIGERATORS .PART 2 – REFRIGERANT R404A","authors":"B. Nowak, P. Życzkowski, R. Łuczak","doi":"10.24425/118883","DOIUrl":"https://doi.org/10.24425/118883","url":null,"abstract":"This paper deals with thermodynamic and thermokinetic properties of R404A refrigerant, which is one of the more commonly used in mine air compression refrigerators. Knowledge of these parameters is essential to analyze performance of such refrigeration equipment, to design it, or to estimate efficiency of air refrigerators using various refrigerants. These properties can be defined using 27 simple computational formulas, contained in 4 tables (Tables 2, 6, 10 and 12). The relationships determining thermodynamic and thermokinetic parameters of R404A occur in saturated liquid region, dry saturated vapor region, superheated vapor region and supercooled liquid region. The developed relationships were subjected to statistical verification. For this purpose, correlation coefficients, coefficients of determination, as well as absolute and relative deviations were determined by comparing results of the calculations with the corresponding results obtained by REFPROP 7 (Lemmon et al., 2002). Results of verification are contained in Tables 14 and 15.","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43472129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Variability of Exploitation Coefficient of Knothe Theory in Relation to Rock Mass Strata Type","authors":"K. Kryzia, T. Majcherczyk, Z. Niedbalski","doi":"10.24425/123696","DOIUrl":"https://doi.org/10.24425/123696","url":null,"abstract":"","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41416529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-20DOI: 10.24425/ams.2021.136688
{"title":"Innovative Technology of Tight Liquidation of Workings on the Example of the Wieliczka Salt Mine","authors":"","doi":"10.24425/ams.2021.136688","DOIUrl":"https://doi.org/10.24425/ams.2021.136688","url":null,"abstract":"","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41467559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-20DOI: 10.24425/AMS.2020.133194
H. Guo, M. Ji, Weisheng Zhao
Through in-situ stress measurements, stress data were obtained from an auxiliary transportation ro- adway in a coal mine in Shanxi Province, China. Based on the principles of elastic mechanics and using a generalized plane strain model, the mechanical effects of the in-situ stresses on an idealized roadway were calculated and the distributions of stresses, displacements, and plastic zones determined. Building on this model, the vulnerable zones in the roadway cross section were identified. Ground support specifica- tions were developed and during specification design, comprehensive consideration was given to factors affecting the stability of the rock surrounding the roadway. A scientific and reasonable support scheme was put forward. Practical experience in the coal mine shows the normal forces of anchor bolt and cable, the minimal convergence of roof to floor, and a generally good support in the auxiliary transportation roadway. The support should ensure safe production during its service life. This study provides a new method for designing roadway support systems that can be particularly valuable for high-stress roadways.
{"title":"Roadway Support Design Based on In-situ Stress and Its Asymmetrical Distributions in a Coal Mine","authors":"H. Guo, M. Ji, Weisheng Zhao","doi":"10.24425/AMS.2020.133194","DOIUrl":"https://doi.org/10.24425/AMS.2020.133194","url":null,"abstract":"Through in-situ stress measurements, stress data were obtained from an auxiliary transportation ro- adway in a coal mine in Shanxi Province, China. Based on the principles of elastic mechanics and using a generalized plane strain model, the mechanical effects of the in-situ stresses on an idealized roadway were calculated and the distributions of stresses, displacements, and plastic zones determined. Building on this model, the vulnerable zones in the roadway cross section were identified. Ground support specifica- tions were developed and during specification design, comprehensive consideration was given to factors affecting the stability of the rock surrounding the roadway. A scientific and reasonable support scheme was put forward. Practical experience in the coal mine shows the normal forces of anchor bolt and cable, the minimal convergence of roof to floor, and a generally good support in the auxiliary transportation roadway. The support should ensure safe production during its service life. This study provides a new method for designing roadway support systems that can be particularly valuable for high-stress roadways.","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45862464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A solution is suggested to the problem which has received a great deal of researchers’ attention in the last twenty years involving the development of a mathematical model of transverse vibration experienced by high-capacity mining skips while they traverse the shaft. Such model, particularly useful when investigating fatigue damage of hoisting skips, is still being sought by engineering practitioners responsible for hoist safety. Models proposed so far have been found unsatisfactory, which was corroborated by research data showing that the underlying assumptions and involved equations need to be modified. This paper highlights the suggested modifications, basing on measurement data and the modified version of the model is verified against those data.
{"title":"MATHEMATICAL MODEL OF TRANSVERSE VIBRATIONS OF A HIGH-CAPACITY MINING SKIP DUE MISALIGNMENT OF THE GUIDING TRACKS IN THE HOISTING SHAFT","authors":"M. Płachno","doi":"10.24425/118882","DOIUrl":"https://doi.org/10.24425/118882","url":null,"abstract":"A solution is suggested to the problem which has received a great deal of researchers’ attention in the last twenty years involving the development of a mathematical model of transverse vibration experienced by high-capacity mining skips while they traverse the shaft. Such model, particularly useful when investigating fatigue damage of hoisting skips, is still being sought by engineering practitioners responsible for hoist safety. Models proposed so far have been found unsatisfactory, which was corroborated by research data showing that the underlying assumptions and involved equations need to be modified. This paper highlights the suggested modifications, basing on measurement data and the modified version of the model is verified against those data.","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46015071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Seismicity and Rock Burst Hazard Assessment in Fault Zones: a Case Study","authors":"K. Tajduś, A. Tajduś, M. Cała","doi":"10.24425/123695","DOIUrl":"https://doi.org/10.24425/123695","url":null,"abstract":"","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":"40 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139357155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-20DOI: 10.24425/AMS.2019.128691
P. Nancel-Penard, A. Parra, N. Morales, C. Díaz, E. Widzyk-Capehart
The economic envelopes obtained by optimization techniques in open pit mining are transformed into operational phases that are suitable for extraction through ramp designs. This process is performed with the aid of specialized design software, which is still very manual, time consuming and highly dependent on the expertise of the planner. In this paper, we introduce a new methodology based on a mathematical model to automatically propose the design of ramps from the economic envelope of a pushback, with the resulting envelope having the maximum value. The developed model was tested against a real case scenario showing reasonable and useable solutions for the planner. Using this approach, a planner can evaluate several alternatives in a reasonable time before selecting the final design.
{"title":"Value-Optimal Design of Ramps in Open Pit Mining","authors":"P. Nancel-Penard, A. Parra, N. Morales, C. Díaz, E. Widzyk-Capehart","doi":"10.24425/AMS.2019.128691","DOIUrl":"https://doi.org/10.24425/AMS.2019.128691","url":null,"abstract":"The economic envelopes obtained by optimization techniques in open pit mining are transformed into operational phases that are suitable for extraction through ramp designs. This process is performed with the aid of specialized design software, which is still very manual, time consuming and highly dependent on the expertise of the planner. In this paper, we introduce a new methodology based on a mathematical model to automatically propose the design of ramps from the economic envelope of a pushback, with the resulting envelope having the maximum value. The developed model was tested against a real case scenario showing reasonable and useable solutions for the planner. Using this approach, a planner can evaluate several alternatives in a reasonable time before selecting the final design.","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43299439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-20DOI: 10.24425/ams.2022.140861
{"title":"Measurements of the Methane Concentration Along the Longwall Excavations and Longwall","authors":"","doi":"10.24425/ams.2022.140861","DOIUrl":"https://doi.org/10.24425/ams.2022.140861","url":null,"abstract":"","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43376119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-20DOI: 10.24425/AMS.2019.128693
P. Kamiński, P. Czaja, Metoda Przeciwdziałania
This work presents an innovative shaft-lining solution which, in accordance with a patent of the Republic of Poland, allows successive, periodic leaching of excess rock salt migrating to the shaft opening. As is commonly known, all workings in rock salt strata are exposed to an increased convergence of sidewalls, making it very difficult to use shafts properly. Rocks migrating towards the shaft opening cause very high stress on the shaft liner. As a result, if the lining does not show substantial deformability, it fails. Lining failure due to insufficient deformability has been extensively described in the literature. Also, throughout the history of mining construction, a number of solutions have been proposed for different types of lining-deformability enhancement. For instance, the KGHM mining corporation applied a deformable steel lining – a solution used in the mining construction of galleries – along a 155-m-long section of the SW-4 shaft with diameters of 7,5 m that passes through a rock salt strata. At KGHM, the SW-4 shaft passes through a rock salt strata along a section of 155 m, in which a deformable enclosed steel lining was made. After several years, the convergence of shaft sidewalls stabilised at a rate of 0.5 mm/day. This enormous activity of the rock mass made it necessary to reconstruct the entire shaft section after only four years. According to further predictions, it will be necessary to reconstruct this section at least four times by 2045. This paper discusses in short form the underlying weaknesses of the technology in question. As a solution to the problems mentioned above, the authors of this work present a very simple design of a shaft lining, called the tubing-aggregate lining, which utilises the leachability of salt rock massifs. The essential part of the lining is a layer of coarse aggregate set between the salt rock sidewall and the inner column of the tubing lining. One the one hand, coarse aggregate supports the salt rock sidewall and is highly deformable due to its compressibility, but on the other hand it allows water or low saturated brine to migrate and dissolve salt rock sidewalls. This paper presents the first stage of works on this subject. Patent No. PL 223831 B had been granted before these works commenced.
{"title":"An Innovative Solution to Counteract Convergence of Shaft Lining in Rock Salt Strata","authors":"P. Kamiński, P. Czaja, Metoda Przeciwdziałania","doi":"10.24425/AMS.2019.128693","DOIUrl":"https://doi.org/10.24425/AMS.2019.128693","url":null,"abstract":"This work presents an innovative shaft-lining solution which, in accordance with a patent of the Republic of Poland, allows successive, periodic leaching of excess rock salt migrating to the shaft opening. As is commonly known, all workings in rock salt strata are exposed to an increased convergence of sidewalls, making it very difficult to use shafts properly. Rocks migrating towards the shaft opening cause very high stress on the shaft liner. As a result, if the lining does not show substantial deformability, it fails. Lining failure due to insufficient deformability has been extensively described in the literature. Also, throughout the history of mining construction, a number of solutions have been proposed for different types of lining-deformability enhancement. For instance, the KGHM mining corporation applied a deformable steel lining – a solution used in the mining construction of galleries – along a 155-m-long section of the SW-4 shaft with diameters of 7,5 m that passes through a rock salt strata. At KGHM, the SW-4 shaft passes through a rock salt strata along a section of 155 m, in which a deformable enclosed steel lining was made. After several years, the convergence of shaft sidewalls stabilised at a rate of 0.5 mm/day. This enormous activity of the rock mass made it necessary to reconstruct the entire shaft section after only four years. According to further predictions, it will be necessary to reconstruct this section at least four times by 2045. This paper discusses in short form the underlying weaknesses of the technology in question. As a solution to the problems mentioned above, the authors of this work present a very simple design of a shaft lining, called the tubing-aggregate lining, which utilises the leachability of salt rock massifs. The essential part of the lining is a layer of coarse aggregate set between the salt rock sidewall and the inner column of the tubing lining. One the one hand, coarse aggregate supports the salt rock sidewall and is highly deformable due to its compressibility, but on the other hand it allows water or low saturated brine to migrate and dissolve salt rock sidewalls. This paper presents the first stage of works on this subject. Patent No. PL 223831 B had been granted before these works commenced.","PeriodicalId":55468,"journal":{"name":"Archives of Mining Sciences","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43489855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：