The Valea Jiului coal basin is the largest mining basin in Romania and includes from east to west the mining fields: Lonea, Lonea-Pilier, Petrila-Sud, Petrila, Livezeni, Salatruc, Dalja, Iscroni, Aninoasa, Vulcan, Paroseni, Lupeni , Lupeni-Sud, Barbateni, Uricani, Valea de Brazi and Campu lui Neag. The first opening works in the Lonea perimeter began with the excavation of the Rascoala gallery, in 1870, a gallery supported by brickwork. Also in the same period, the up-to-date exploitation of the outcrops from the Jiet Valley area and the neighboring valleys is proposed. The general ventilation of the Lonea mine is ascending under the influence of the general depression created by the three main ventilation stations. The analysis performed on the Lonea mine ventilation network leads to the conclusion that the mine ventilation network is particularly complex, a complexity amplified by the large number of air control and regulation constructions. In order to evaluate in perspective the influence of the changes that will occur in the ventilation network of the mine regarding the distribution of air currents both in size and in the direction of their flow, of the locations of the constructions for directing and regulating air flows, as well as the types of ventilation mining constructions that are necessary for the desired distribution, modeling and simulation programs were used that allow the option of visualizing the network in three and two-dimensional system, for the representation of the ventilation network of the Lonea mine. This paper presents the analysis of the complex ventilation network of the Lonea Mine with the help of specialized programs.

The main role of ventilation systems and especially air conditioning systems is to create indoor conditions and air quality inside the rooms that are independent of external atmospheric influences. The sizing of ventilation systems and especially of air conditioning systems is done, in most cases, by considering the climatic elements as a basis for calculation. The real limit to air quality insurance it consists in maintaining in the air certain concentrations of harmful substances which do not endanger human health and do not create discomfort. The air condition parameters of interest for the ventilation and air conditioning technique are air temperature and humidity, atmospheric pressure and air velocity. For this study, in the experimental laboratory, the test was performed on the variation of the air condition parameters in the conditions of conveying a quantity of methane gas through the ventilation duct. During the experiment, the operating parameters of the drive motor were changed using a frequency converter on levels 50; 40; 30; 20; 10 and 5 Hz. The ventilation system used was structured by means of flow converters which were fixed in the open position. The ventilation system as well as the flow variators were operated by the SCADA type command and control system. The paper will present the analysis of the variation of the state parameters (temperature, humidity, absolute pressure and air velocity) by introducing a constant amount of methane gas in the ventilation duct.

The energy crisis triggered globally in the last quarter of 2021, forced Romania to go through a winter with liberalized electricity and gas prices, a period unprecedented in terms of consumer prices, accentuated by the result of closing energy targets that coalfired operations as a result of the imposition of EU conditions for the restructuring of the mining and energy sector. The year before, 2020, the COVID-19 pandemic, with restrictions imposed, produced a decrease in electricity demand, a decline in coal-fired power consumption, greatly reduced the share of gas in the energy mix, using preferential renewable energy sources. Subsequently, Russian gas prices have risen to record highs and, as a result, coal-fired power generation has returned to the European Union in 2021, although coal became more expensive and emission allowance prices doubled. In the context of the armed conflict between Russia and Ukraine, major price increases are expected worldwide, generating new risks of exposing the economy and new challenges in terms of ensuring Romania's independence and energy security. Against this background of these situations, can Romania still respect the European commitments of the Green Pact, meet these challenges and respond to the needs of the communities affected by the projected programs? The present paper aims at a critical assessment of the current situation of the Romanian coal mining and future trends of using a �clean coal� as a variant to respond to the requirements of the environmental concerns.