In the present monograph, various issues related to current ventilations problems in hard coal mines are discussed. The authors' primary objective is to show how numerous technological problems need to be solved in order to guarantee proper ventilation during exploatation of coal seams in the presence of methane emission, hard thermal environment and spontaneous fire risk.
Mining progress and the movement of working areas frequently cause the length of primary intake and return routes to increase, which in turn increases the total resistance of a complex ventilation network. The development of a mine can make it necessary to step up airflow rate in a ventilation network. In complex ventilation networks, the number of downcast shafts is usually greater than that of upcast shafts. The possibility of installing subsurface main fan station at downcast shafts, aimed at increasing primary ventilation capacity in the mine, is discussed among othersin the monograph.
W niniejszej monografii omówiono różne zagadnienia związane z problemami wentylacji w kopalniach węgla kamiennego. Głównym celem autorów jest wykazanie, jak wiele problemów technologicznych musi być rozwiązanych w celu zapewnienia właściwej wentylacji podczas eksploatacji pokładów węgla w obecności emisji metanu, trudnego środowiska cieplnego i zagrożenia pożarem endogenicznym.
Prowadzenie eksploatacji i przemieszczanie się obszarów wydobywczych często powodują, że długość dróg doprowadzania i odprowadzania powietrza wzrasta, co z kolei zwiększa opór zastępczy złożonej sieci wentylacyjnej. Rozwój kopalni może wymagać zwiększenia ilości przepływającego powietrza w sieci wentylacyjnej. W złożonych sieciach wentylacyjnych liczba szybów wdechowych jest zwykle większa niż w przypadku szybów wydechowych. W monografii omówiono między innymi możliwość zainstalowania podziemnej stacji wentylatorów głównego przewietrzania przy szybie wdechowym, która ma na celu zwiększenie zdolności wentylacyjnej kopalni.
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Introduction 7
1. Analysis of the impact of connecting a forcing fan to a multiple fan ventilation network of a real-life mine 11
1.1. Introduction and background 11
1.2. Airflow distribution in the ventilation network of a mine: theoretical foundations of the calculations 12
1.3. The impact of adding another forcing fan on primary ventilation capacity in a simple ventilation network with one exhaust fan 14
1.4. P-S copper ore mine – case study 17
1.5. Assumptions and calculations 18
1.6. Analysis of the results 23
1.7. Conclusions 26
References 282. Using AGHWEN software to design auxiliary ventilation under the conditions of methane and temperature hazards 29
2.1. Introduction 29
2.2. Characteristics of duct fans 31
2.3. Choosing a duct fan for efficient cooperation with a leaking air duct 32
2.4. The distribution of methane concentration in a heading 33
2.5. Software for designing and calculating parametres of leaking air ducts 39
2.6. A sample design of an air duct and ventilation of a heading 41
2.6.1. Design parametres of headings 41
2.6.2. Project assumptions 42
2.6.3. Analysis of the calculated values 43
2.7. Conclusions 48
References 483. State of methane hazard in Polish hard coal mines and methods of its prevention 50
3.1. Introduction 50
3.2. Methane hazard in Polish hard coal mines 50
3.3. Longwall ventilation systems 52
3.4. Systems of longwall methane drainage 54
3.5. Recommendations for exploitation design process having regards to aerological hazards 56
3.6. Conclusions 58
References 594. Measurements of Coalbed Methane Content 60
4.1. Introduction 60
4.2. Review of methods for measurement Coalbed Methane Content 61
4.2.1. Introduction 61
4.2.2. Direct methods 61
4.2.3. Direct methods used in Polish coal mines 63
4.3. Measuring Coalbed Methene Content according to the Polish Standard PN-G-44200:2013-10 64
4.3.1. Introduction 64
4.3.2. Loss of methane connected with collecting coal samples for measurements 67
4.3.3. The procedure of determining Coalbed Methane Content 69
4.4. Measurement uncertainty of Coalbed Methane Content 70
4.4.1. Introduction 70
4.4.2. Analysis of measurement uncertainty of coalbed methane content 71
4.5. AGH-GAZ software for determining the Coalbed Methane Content 73
4.6. Conclusions 76
References 765. Current state of utilization of methane from Polish hard coal mines 79
5.1. Introduction 79
5.2. Methane resources in hard coal deposits in Poland 79
5.3. Methods of capturing Coalbed Methane 80
5.4. Methods of methane drainage and their efficiency in Polish coal mines 83
5.5. The current system of supporting the utilization of methane from hard coal mines 87
5.6. Utilizing the captured methane 88
5.7. Conclusions 89
References 906. A method for determining the effectiveness of inertisation of self-heating places in the goaf of a longwall in hard coal mines 92
6.1. Introduction 92
6.2. Estimation of inertisation effectiveness 93
6.3. Basic assumptions of computer programmes written to simulate air flow distribution in goaf 94
6.4. Example of using written computer programmes 97
6.5. Conclusions 101
References 1027. Mine cooling systems in Polish coal mining 103
7.1. Introduction 103
7.2. Factors causing an increase in thermal hazard 103
7.3. Underground refrigeration and mine cooling systems 105
7.3.1. Introduction 105
7.3.2. Local cooling system 106
7.3.3. Group cooling system 106
7.3.4. Central cooling system 106
7.4. Cooling systems in Polish coal mines 110
7.5. Group cooling systems 113
7.6. Conclusions 115
References 1168. Influence of ventilation and air cooling on thermal regime in the excavation at great depth 117
8.1. Introduction 117
8.2. Parametres of underground excavations on planned level 1290m 118
8.3. Forecast of thermal conditions 119
8.3.1. Assumptions for the forecast without thermal insulation 119
8.3.2. Assumptions for the forecast of air temperature in excavations with thermal insulation of side walls 122
8.4. Results of forecast of thermal conditions in the excavation with thermal insulation of side walls 123
8.5. Results of forecast of thermal conditions in the excavation without thermal insulation 125
8.6. Discussion of results 126
8.7. Conclusions 128
References 1289. Thermodynamic measurements of a multi-jacket air duct cooler under the conditions of a mine 130
9.1. Introduction 130
9.2. The test method 131
9.3. Measurement results 131
9.4. The model of heat transfer in a multi-jacket air duct cooler 135
9.5. Conclusions 141
References 14210. Controlling the distribution of cold water in air cooling systems of underground mines 143
10.1. Introduction 143
10.2. Principles for regulating the distribution of cold water in the cooling systems 145
10.3. Regulating the cooling power of air coolers 148
10.4. Requirements concerning control systems 150
10.4.1. System for controlling the flow of cold water through the cooler 150
10.4.2. System for controlling water parametres at the inlet of the district 151
10.4.3. Master control system for controlling the parametres of water in a cooling system 154
10.5. Example of monitoring and controlling the parametres of cold water in a cooling system 154
10.6. Conclusions 155
References 156