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Abstract To investigate the dispersion process of the underground toxic gas carbon monoxide (CO) into the refuge chamber during a mine disaster and enhance the survival rate of trapped miners, a simplified model of an underground refuge chamber and the main roadway was constructed. The impact of temperature and pressurized air volume on CO dispersion into the refuge chamber has been examined through both analog experiments and numerical simulations, and the reliability of the simulation results was verified. The results indicate that CO dispersion into the refuge chamber through the top of the protective isolation door occurs when the temperature in the refuge chamber is lower than that of the toxic gas. When the temperature of the toxic gas is higher, it tends to enter the refuge chamber through the bottom of the protective isolation door. The evolution of CO concentration in the transition chamber can be divided toxic survival chamber can be categorized into a sudden decline stage and a stable stage. And a flexible isolation door designed to control the entry of toxic gases into the refuge chamber was implemented, and its impact on CO dispersion has been compared and analyzed. When the temperature of the main roadway is 50 °C and the temperature of the refuge chamber is 20 °C, the required pressurized air volume to maintain the CO concentration within the safe threshold (24 ppm) is reduced to 69.6% of that needed without the isolation door, thereby significantly reducing the infiltration of harmful gases from the main roadway into the refuge chamber.

To investigate the dispersion process of the underground toxic gas carbon monoxide (CO) into the refuge chamber during a mine disaster and enhance the survival rate of trapped miners, a simplified model of an underground refuge chamber and the main roadway was constructed. The impact of temperature and pressurized air volume on CO dispersion into the refuge chamber has been examined through both analog experiments and numerical simulations, and the reliability of the simulation results was verified. The results indicate that CO dispersion into the refuge chamber through the top of the protective isolation door occurs when the temperature in the refuge chamber is lower than that of the toxic gas. When the temperature of the toxic gas is higher, it tends to enter the refuge chamber through the bottom of the protective isolation door. The evolution of CO concentration in the transition chamber can be divided toxic survival chamber can be categorized into a sudden decline stage and a stable stage. And a flexible isolation door designed to control the entry of toxic gases into the refuge chamber was implemented, and its impact on CO dispersion has been compared and analyzed. When the temperature of the main roadway is 50 °C and the temperature of the refuge chamber is 20 °C, the required pressurized air volume to maintain the CO concentration within the safe threshold (24 ppm) is reduced to 69.6% of that needed without the isolation door, thereby significantly reducing the infiltration of harmful gases from the main roadway into the refuge chamber. [ABSTRACT FROM AUTHOR]

Purpose is to study the influence of mining and geological conditions on the time-dependent stability of the collective refuge chamber for mine workers with the adjacent mine workings and develop support schemes for different conditions of construction of such mine workings. Methods. Numerical modelling methods of the connected processes of elastoplastic deformation of gas-bearing rocks and gas filtration within the area disturbed during mining operations were used to study stability of mine workings with a compound cross-section, i.e. the collective refuge chambers and its adjacent extraction gallery. The model was based on fundamental principles of solid mechanics and filtration theory. The problem was solved using a finite element method. Findings. A classification of the conditions for locating collective refuge chambers for mine workers according to the relative strength of the enclosing rocks was developed. Support schemes for the chamber and its adjacent mine working were elaborated. The schemes include basic support and provide for its strengthening with rock bolts located in the roof of the mine working and chamber, or in their walls. The compliance of these support schemes with the developed classification of location conditions was determined. A numerical study of the time-dependent stability of the chamber and its adjacent mine working, while applying the recommended support scheme, was performed. It is shown that the strengthening of rock bolting schemes reduces the multicomponent stress field and the area of the zone of inelastic deformations, forms a rock-bolt overlap in the roof of the mine workings and chambers, which helps increase their stability under the complicated mining and geological conditions. Originality. Dependence of the changes within the area of a zone of inelastic deformations around the chamber with its adjacent mine working on the relative strength of the enclosing rocks was identified; time-dependent changes within the area of the zone of inelastic deformations, when using different support types, were specified. Practical implications. Support schemes for collective rescue chambers for mine workers in terms of different construction conditions were developed along with the procedure of their selection for specific mining and geological conditions. The results of the study provide theoretical substantiation and scientific guidelines for the selection of supports for collective refuge chambers adjacent to the mine working. [ABSTRACT FROM AUTHOR]

A method of heat storage and temperature control for refuge chamber with phase change energy storage wall is put forward, that is, coupled temperature control method of mine air pressure, phase change cold storage for energy storage wall under conventional condition, and wall phase change heat absorption when mine accident occurs, the diatomaceous earth-based phase change material was used as the energy storage aggregate additive to prepare composite cement mortar, which was then laid on the wall of the refuge chamber to achieve temperature control effect. The test results show that when the amount of energy storage aggregate is 15% and the amount of activated carbon is 6%, the prepared composite cement mortar can be adapted to the energy storage wall structure of the refuge chamber and improve the indoor thermal environment of the refuge chamber.

The refuge chamber provides a safe space where people can stay safe when they are trapped by an accident in a coal mine. The refuge chamber includes several systems such as oxygen supply, air purification, cooling, and dehumidifying. The oxygen supply system is the core of the refuge chamber because it is a closed environment. The oxygen supply time is 96 h according to the relevant standards in America and China. If people stay in the refuge chamber for more than 96 h, the oxygen supply may not be enough, and they can be in danger. It is necessary to efficiently use oxygen and extend the oxygen supply time. Based on the experimental platform of the refuge chamber, this paper conducts an in-depth study on the automatic control of the oxygen supply system. The oxygen supply system and the harmful gas removal system can be automatically and efficiently controlled by the programmable logic controller (PLC) according to the personnel number and the oxygen concentration. The experiment has proved that the system is good and reliable. [ABSTRACT FROM AUTHOR]

In order to test the anti-impact performance of the refuge chamber and verify the reliability of the experiment on the scaled model of the refuge chamber, the reduced-scale model and the original model of the refuge chamber were established in this paper. By using the finite element software ANSYS Workbench, the dynamic response results of the two models under impact loading are simulated and analyzed. The results show that the response results of the reduced scale model are similar to the original scale model. The response results of the reduced scale model of the rescue capsule under impact load can be used to reasonably and effectively reflect the response results of the original scale model of the rescue capsule.

The refuge chamber provides a safe space where people can stay safe when they are trapped by an accident in a coal mine. The refuge chamber includes several systems such as oxygen supply, air purification, cooling, and dehumidifying. The oxygen supply system is the core of the refuge chamber because it is a closed environment. The oxygen supply time is 96 h according to the relevant standards in America and China. If people stay in the refuge chamber for more than 96 h, the oxygen supply may not be enough, and they can be in danger. It is necessary to efficiently use oxygen and extend the oxygen supply time. Based on the experimental platform of the refuge chamber, this paper conducts an in-depth study on the automatic control of the oxygen supply system. The oxygen supply system and the harmful gas removal system can be automatically and efficiently controlled by the programmable logic controller (PLC) according to the personnel number and the oxygen concentration. The experiment has proved that the system is good and reliable.

In view of the problem that the quantitative relationship between the impact factors of the anti-explosion and the weight of the refuge chamber is not clear, this paper adopts the finite element method based on an actual chamber to study the factors of outer skin thickening, stiffener thickening and flange thickening. The improvement of anti-explosion performance of refuge chamber with different cross-sections, and the calculation of the weight increase value of the chamber under different factors were calculated. The quantitative relationship between the anti-explosion strength improvement and the weight increase was analyzed. The results show that when the same weight is increased, changing the thickness of the stiffener has the most apparent effect on the anti-explosion performance of the chamber. It is 5.3 times higher than the skin thickening and 2.7 times higher than the flange thickening, which is the most economical and reasonable method for improving explosive performance.

The air purification system of refuge chamber is an important part of underground emergency, which can provide the good living environment for underground emergency evacuation personnel. In this paper, the similar simulation method is used to establish a CO purification experiment model of refuge chamber. Several sets of comparative experiments are carried out. The change law of CO concentration under different wind speeds, different doses and different volumes are analyzed. The judgment criteria for CO purification detection are proposed. The results show that the purification rate of CO increases first and then decreases with the increase of wind speed and dose, and the average purification rate varies by about 5%. When the space velocity value is around 183 418 h-1, the CO purification reaction rate is the fastest. Moreover, the chamber volume of the experimental model has little effect on the purification capacity.

The basic requirements for the protective sealing door(wall), transition chamber, living room, emergency exits and other structure of refuge chamber are presented in this paper. The refuge chamber should have all or part of functions of safety protection, oxygen supply, removing harmful gas, temperature and humidity control, environmental monitoring, lighting, communication, life support, and meet the corresponding requirements. In the process of the refuge chamber design, the targeted design calculation and scheme optimization should be carried out according to the specific conditions.

In view of problem that most of existing oxygen supply systems of refuge chamber applied multistage protection system, and oxygen supply subsystems are independent of each other and cannot automatically switch among them, which causes the oxygen supply unstable, an automatic oxygen supply system of refuge chamber based on PLC and PID monitoring technology was designed. The system integrates multistage oxygen supply systems and environment parameters monitoring system through loop optical fiber system. Based on the detected environment parameters in real-time, and uses PLC and PID monitoring technology, the system can realize intelligent adjustment between all levels of oxygen supply system and automatic continuous supply oxygen of underground refuge chamber, and can automatically switch to the next level of oxygen supply system when a certain level of oxygen supply system happens failure, which improves stability and safety of the oxygen supply of refuge chamber. The site test results verify reliability of the system.

Structural analysis is important in the design of a refuge chamber, which can ensure the structural safety of the refuge chamber in case of an explosion. In this paper, an indirect coupling method is utilized to calculate deformation of a refuge chamber under explosion, when gas explosion is simulated in a roadway model, and the pressure waves on different locations of chamber are extracted. The extracted pressure-time curves are applied to a detailed model of the refuge chamber to obtain deformation values. However, reliabilities and validities of the simulation results are not provided. Thereby, we conducted three groups of small-scale physical experiments for comparing the corresponding simulation results calculated by the indirect coupling method. Meanwhile, the theoretical values were obtained by the method of extracting the specific impulse. The results show that the simulation values fit well with the experimental and theoretical values. The process of applying a pressure-time curve to the model covers the specific impulse which acts on the prototype. This method can be used to calculate the deformation of complex equipment under explosion. [ABSTRACT FROM AUTHOR]

In order to explore the effect of gas explosion on the refuge chamber of coal mine, this paper carried out a numerical simulation on the process of gas explosion under the closed and open condition respectively. The physical model of the refuge chamber was established by means of applying the software of ICEM, and then Fluent software was used to carry out the numerical simulation on the pressure and temperature variation of gas explosion under different boundaries. In addition, The Origin software was used to carry out the curve fitting of the pressure as well as the temperature variation during the process of the gas explosion. The results show that under the sealing condition, the refuge chamber need withstand the high pressure of 0.61 MPa and the high temperature of 2269 K; under the condition of opening, the refuge chamber only need withstand the overpressure of 12.39 KPa and the high temperature of 1773 K respectively. Considering comprehensively the explosion overpressure and the high temperature, the position of the refuge chamber should be far away from the dead end roadway. [ABSTRACT FROM AUTHOR]

Relationship formula between average concentration of harmful gas and pressure ventilation supply volume in refuge chamber was given, CO2 concentration distribution in refuge chamber under conditions of different pressure ventilation supply volume and air outlet layout were analyzed through refuge experiment with 50 people. The experimental results show that when air supply volume per person is 84 L/min, CO2 volume fraction in refuge chamber could be controlled under 1%; CO2 concentration distribution is uneven when only one air outlet is set in refuge chamber, air outlets should be evenly arranged in both sides of long passage of refuge chamber, and CO2 concentration distribution is more even with more air outlets.

Highlights • A new coupled cooling method implementing a phase change chair (PCC) was proposed. • Simplified numerical models of PCC and coupled cooling system were established. • The indoor temperature could reduce by 4 °C in contrast to the case without PCC. • Conditions of achieving the optimal thermal control effects were proposed. Abstract A latent heat thermal energy storage system is a safe, stable, and reliable method of controlling the room temperature. However, this system is difficult to fit in some harsh environments such as a mine refuge chamber where the temperature is high. In this article, a new coupled cooling method implementing a phase change chair (PCC) is proposed, which is not only suitable for harsh environments, but also saves valuable living space. A new PCC model and a simplified coupled heat transfer model considering the air, surrounding rock, PCC, and heat source are established. The effects of melting temperature, latent heat, thermal conductivity, and thickness of PCC were systematically investigated. The analysis results indicated that: (i) the coupled cooling method based on the PCC could effectively control the temperature in 40 h. (ii) under the given operating conditions, the optimal melting temperature is approximately 27 °C, and the thermal conductivity of PCC is 0.6 W/m K. (iii) increasing the latent heat and the thickness of PCC has a similar effect on temperature control. For every 30 kJ/kg increase in the latent heat or 0.01 m increase in the thickness, the control time increases by 4.5 h, but the effect gradually decreases. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The basic function of a refuge chamber is to maintain reasonable concentrations of O 2 , CO 2 , and CO. The supply of compressed oxygen in a refuge chamber is always limited. Therefore, it is vitally important to determine how to make the most effective use of compressed oxygen and maximize its supply time. In this paper, we determine the basic law of gas leakage in refuge chamber and reveal that the higher is the pressure in the refuge chamber, the more oxygen leakage occurs. We examine the law of supply and consumption of compressed oxygen and its interrelationship with the air cleaning system. An excessive supply of compressed oxygen only serves to increase its consumption with no positive effect on air quality. However, air cleaning systems can not only decrease the carbon dioxide concentration but also increase the oxygen concentration. Therefore, the compressed oxygen supply and air purification system must be simultaneously enabled to maintain a reasonable air concentrations in the chamber. And the oxygen supply rate should be dynamically adjusted according to human need. [ABSTRACT FROM AUTHOR]

The paper analyzed special pipeline technology for emergency refuge, and pointed out that “six systems” with the special pipeline for underground safe refuge can improve anti-disaster ability of pipeline, but the underground safe refuge system derived from the special pipeline cannot replace coal mine communication system, monitoring and control system and personnel positioning system, and it cannot perceive disasters. It compared and analyzed technical characteristics of life-saving shelter and refuge chamber, pointed out that the life-saving shelter has shortcomings of being susceptible by disaster, needs cooling and high cost. It put forward that coal mine should be equipped with high-power submersible pump, and should be careful to use rescue equipments of flood drilling. It proposed area captain and group leaders should be part-time draegerman. It also proposed that hand-over works should try to be completed on the ground, so as to reduce underground personnel.

A multifunctional ice storage air conditioning system was designed and its working principle, working mode and structure modification were improved. It can achieve cooling, dehumidification when the energy supply is either exhausted or adequate. The PMV grade method has been modified and applied, and thermal comfort model is obtained and the acceptable upper limit of human body temperature and humidity tolerance range is 35 °C and 80% RH. Thermal load and humidity load model were defined, analyzed, and verified by human survival experiments. Finally the optimization performance of this ice storage air conditioning system was validated through theoretical calculation and experimental verification and technical parameters appropriate for engineering applications were analyzed. The temperature and humidity in refuge chamber are eventually controlled at 31°Cand 77% RH. According to the experiment subjects, the living environment in refuge chamber is quite comfortable and thermal sensation is not stuffy. It can be concluded that the energy consumption of air conditioning fan was reduced by 35%, the ice storage needed was reduced by 15%, the rated air velocity of air conditioning was analyzed and the effective working time of this system was determined to be not below 96 h for 8 persons to survive in a refuge chamber. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cooling system for mine refuge chamber provides comfortable environment for miners to avoid heat damage. The existing cooling systems have their own application scopes and limitations. The coupled cooling method of Latent Heat Thermal Energy Storage (LHTES) combined with pre-cooling of envelope (PE) is a new free cooling method which is suitable for high-temperature, passive, impact and other harsh environment. Then, to improve the thermal comfort and reduce energy consumption, the effect of the pre-cooling temperature, melting temperature of PCM, aspect ratio and amounts of PCM unit on the indoor temperature are investigated in a systematic manner. Furthermore, the system is optimized and the generalized results for the evaluation parameter are given. Analysis of the results may lead to following main conclusions: (i) the method really controls the indoor temperature and the saving amount of PCM is more than 50% compared to the traditional LHTES systems; (ii) the temperature control (TC) performance of PCM would drop significantly if it melts more than 80%; (iii) under current operating conditions, the optimal melting temperature is about 29 °C and the aspect ratio of PCM unit is 60:500; (iv) per 1 °C the pre-cooling temperature dropped, 19% the actual amount of PCM decreased for the case studied. [ABSTRACT FROM AUTHOR]

Temperature and humidity control in underground refuge chamber is an important issue in the case of power failure after a disaster. In this article, an ice storage air conditioner was newly developed for refuge chambers. A series of tests were conducted to investigate the ice storage, cooling, and dehumidification performance of the air conditioner. In addition, based on the orthogonal experimental principle, the effect of the key inlet air parameters such as speed, temperature and relative humidity on the cooling and dehumidification performance was analyzed in a systematic manner. Results show that: (i) the ice storage function could be completed by freezing the ice to below −15 °C within 60 h. After testing for 96 h, the outlet air temperature of the ice storage air conditioner is less than 23 °C; (ii) the effect of the inlet air parameters on the cooling and dehumidification performance could be found as velocity > temperature > relative humidity; (iii) the dehumidification efficiency of the ice storage air conditioner could decrease by 12.81%, while the cooling efficiency could decrease by 14.11% when the inlet air velocity increases from 5 m/s to 15 m/s. • An air conditioner combining ice storage and compressed air has been developed for refuge chamber. • The conditioner can meet the temperature control requirement of 15 people in a refuge chamber with an initial surrounding rock temperature of 30 °C. • The cooling and dehumidification performance of the conditioner is affected by velocity, temperature and relative humidity of inlet air in turn. • Suggestions for the practical engineering application of the air conditioner are given. [ABSTRACT FROM AUTHOR]

Once initiated, coal mine belt fires can develop rapidly, and if improperly controlled, these fires could easily lead to the airflow disorders that undermine the function of the ventilation system, and the smoke plume could lead to heavy casualties. However, belt fires can be effectively prevented by establishing a fire smoke plume control system. According to the characteristics of fire smoke plume control in the ventilation network, models of ventilation systems are analyzed, and different methods of fire emergency rescue systems are designed. A mathematical model for fire smoke flow was developed based on the west-wing mining area in Long-Dong coal mine. The distributions of the smoke parameters and airflow temperature on the roadway before and after performing the smoke flow control measures were simulated by Fluent software. The results indicate that 37 min after the fire began, the smoke plume had invaded all of the roadways in the west-wing mining area. The average temperature of the roadway in the west mining area is 332 K, the O concentration is 14.8 %, the CO concentration is 5.1 % and the highest concentration of CO is 0.98 %. In this environment, miners in distress are unable to survive. A function to adjust the opening degree of the air-doors was designed, and the air volume control of the key branches was realized during a fire emergency rescue. A permanent refuge chamber was situated in the mining area to provide a safe shelter for miners when a disaster occurs. Many field exercises have verified the combined function of the emergency rescue system and refuge chamber to ensure the security of the miners in the underground coal mine. [ABSTRACT FROM AUTHOR]

Air curtain systems for mine refuge chambers prevent harmful gases in the tunnel from entering the chambers, but their barrier efficiency is affected by their structural parameters, installation location and air flow angle as well as the size of the chamber door. Previous studies focused on air curtain systems installed on the top of the door frames of the mine rescue capsule, but no studies have investigated air curtain systems installed on two or three sides of the door frames. To improve the barrier efficiency of air curtain systems for refuge chambers, this study conducted an experimental investigation of the effects of the structural parameters, installation location, and air flow angle on the barrier efficiency for a constant size of the door frame. The results demonstrate that air curtain systems with air curtains installed on two sides of the door frame behind the door wall that ejected air parallel to the door frame provided a relatively good barrier effect; an air curtain system that used pipeline air curtains with a nozzle diameter of 1 mm and a nozzle distance of 15 mm exhibited a relatively good barrier effect and a barrier efficiency of 55-60%. In air curtain systems that use air knives, the air knife gap should be 0.1-0.2 mm wide. Under reasonable parameters and installation conditions, there was no significant difference between the barrier effects against CO2 of air curtain systems that use pipeline air curtains and those that use air knives. [ABSTRACT FROM AUTHOR]

A gas and coal dust explosion is potential hazard in majority coal mines. A coal mine mobile refuge chamber is a new class of device for miners those who are unable to escape after an accident which can provide basic survival conditions. In this paper, in order to study the propagation law of an underground methane/air mixture explosive wave, and check the failure mode of a coal mine mobile refuge chamber, a full-sized underground tunnel model and a refuge chamber model have been established in ANSYS/LS-DYNA (LSTC, R7.0.0, Livermore, CA, USA, 2014). The simulation results show that the reflected wave pressure on the front surface of the refuge chamber was about twice as high than the incident wave. The pressure on various locations of the chamber was also analyzed. When the peak pressure of the explosive shockwave reached 0.64 MPa, the maximum displacement and stress occur at the center of the front door and the joint of stiffeners and the front plate, respectively. Most parts of the coal mine mobile refuge chamber were in a plastic failure state and the refuge chamber could be defined as damaged. The front door, the front plate, the connecting flange, and the stiffeners on each side were the primary key components. In the end, suggestions were proposed for the refuge chamber. [ABSTRACT FROM AUTHOR]

Airtight blast door, as the critical component of underground coal mine, requires high quality. Topology and shape optimization were seldom applied in the structure design of products though they were proposed early. Based on those optimization methods and the experience of structure design, a new kind of airtight blast door was developed in this paper. The main component weight of thus kind of door is 14 % smaller than the current airtight blast door without reducing the blast and impact behavior. The typical optimization method and the example presented in this paper are useful for the original development and optimization design in other products. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to meet special requirements of backup power in coal mine refuge chamber, firstly serial lithium-ion batteries were put in an explosion protection box with their battery management system. Then parallel explosion protection boxes formed the backup power system. The system included voltage detection and balance controller, battery pack module controller, assembly controller, LCD controller. It collected voltage and temperature data by distribution voltage sampling method and DS18B20 temperature sensor. It collected current data by current hall sensors. Then system took steps to prevent over voltage, over temperature, over current etc. Through field test verification, system operation was stead)', measuring error of current and voltage were far less than the specified value of coal mine safety standards. [ABSTRACT FROM AUTHOR]

As for the strength check explosion experiment limitations of refuge chamber such as the complicated procedure, difficult result assessment and high costs, the paper puts forward a FEM simulation method, which was to analyze the dynamic respond of the chamber parts under gas explosion on the basis of flow field load, resulted from the stimulation of gas explosion in the roadway by two soft wares of AUTODYN and LS-DYNA being approved by National Mine Product Safety Certificate Center. The analysis results showed that the structure of the existing KJYF-96/8 refuge chamber kept integral against the front blasting pressure of 0. 6 MPa and its key parts were undamaged, which was in accordance with the national regulation. By this way, the weakness of key parts for the refuge chamber could be found out and calculated to save research time and costs. [ABSTRACT FROM AUTHOR]

It is important to remove the carbon dioxide produced by human metabolism in the limited confined space of some emergency or work during a long time rescue, such as refuge chamber or manned spacecraft. Compared with other absorbent, the sodium lime has more stable performance, more mature technology and more reasonable price, which is the irreplaceable advantage as an absorbent used for air purification in the confined space. Due to the special conditions ( such as interruption of power outside, volume restrictions and so on) after coal main disaster, the sodium lime is required to have higher adsorption efficiency and rate. In this paper, six kinds of sodium lime products were selected according to particle size, composition, adsorption efficiency and other conditions. According to the test that the sodium lime absorbing carbon dioxide under different composition, thickness, wind speed, temperature and humidity, the best recipe, the best work mode and best use conditions of soda lime were determined. The conclusion of this study provides the necessary data support and theoretical guidance to determine potassium superoxide medicine plate in confined spaces such as refuge chamber using conditions, optimizing the allocation, developing environment control and life support technology and equipment. [ABSTRACT FROM AUTHOR]

In order to obtain refuge chamber shell structures with the requirements of high strength, low weight, and enough volume, the basic dimensions of the shell structure were first determined on the basis of statics analysis and steel pressure vessel standards. Following that, four shell structures with detailed dimensions reinforcing rib were designed, including shell with internal steel, internal rectangular tubes, external steel, and external rectangular tube to prevent failure. The explicit nonlinear dynamic analysis program was used to simulate the response of the four types. A shock wave of 300 ms duration and 1.0 MPa at its highest value was applied to the shell. The maximum displacement was less than 20 mm, located in the central part of sides and the outer space of portals. The maximum stress was below the strength limit, located in an intermediate position and on the corner of reinforcing rib. The calculations indicated that none of the four structures demonstrated deformation failure or strength failure. This shows they are able to meet safety requirements. Simulations were conducted to verify the results. The situation suitable for each shell structure was demonstrated in the simulation results. A small cabin might be built with the external rectangular tube, and a medium-sized cabin with internal steel. Large cabins may be constructed using internal steel and the external rectangular tube. The impact performance of the shell structure can be optimized if the weak link is locally strengthened. [ABSTRACT FROM AUTHOR]

Abstract: We identified the main heat source of the refuge chamber was hedge staff by analyzing the heat source of the refuge chamber. We identified the calculation method of the heat released by the hedge staff and calcium hydroxide when absorbed CO2. We designed the experimental program of temperature control of phase change material according to the estimate of heat dissipating capacity in 96hours. Ultimately, we conducted simulation experiments and verified the effect of temperature control of the phase change material. [Copyright &y& Elsevier]

Abstract: In order to reduce the risk of sealing and improve the structural strength safety for coal mine mobile refuge chamber, two models with certain proportion were set up after mechanical analysis. One was one-piece coal mine mobiles refuge chamber form which involves less sealing problems between sections, the other was segmented coal mine mobiles refuge chamber form which is easy to transport. A simulation analysis method was used to confirm their structure safety. Verified finite element analysis method was used to simulate the responses under blast loading. Considering the harsh conditions, the maximum pressure of the triangle impact load was 0.8MPa, and the pulse width was 300ms. The maximum stress of one-piece one is less than segmented one. It demonstrated that section connecting position can cause more stress concentration. The maximum displacement one of one-piece is more than segmented one. It demonstrated that segmented type had lower displacement. Weak part of one-piece was middle position of front and back end shell. Weak parts of segmented type were middle position of sides and section connecting position. Based on their weak places analyzed, suggestions were put forward for the two kinds. Arc structure might be used in the front and back end shell. The front and back end shell might be thickened. Only inclined shaft with larger wellhead is suitable for this type. Segmented type could be used in large or medium-sized one. [Copyright &y& Elsevier]

Abstract: Put forward the refuge chamber system composed by permanent refuge chamber, temporary refuge chamber and rescue capsule, which are mutually independent and tightly-coupled, to cost-effectively radiate all the areas with mining activities and protect personnel in mine. In addition, in order to promote the development of refuge chamber system in Chinese coal mine, propose some basically design principles of refuge chamber system and describe the arrangement principles and structure characteristics of three kinds of refuge space in the process of underground refuge chamber system design and construction. It is a significant reference for coal mine refuge chamber system construction in China. [Copyright &y& Elsevier]

Abstract: In order to check structural strength of coal mine mobiles refuge chamber, and do security evaluation of the mobile refuge chamber, a refuge chamber model was established, then a finite element method was instituted for it to ensure the refuge chamber would not be severely damaged when gas or coal dust explosion suddenly happened. A triangle shock wave with 1.2MPa over-pressure, 300ms lasting time was settled. Explicit nonlinear dynamic analysis program was used to simulate response of the refuge chamber. The maximum stress was 244MPa, located in central part of sides and tail end of the last capsule. The maximum displacement was 29.32mm, located in central part of sides and tail end of the last capsule. The calculation indicated that the refuge chamber was not obviously damaged. It could reliable work to meet safety requirements. Compared with the reported experimental results, the simulation method was verified. Based on analysis, suggestions were put forward for further improving. [Copyright &y& Elsevier]

Abstract: Refuge chamber is a kind of rescue equipment that protects trapped miners waiting for rescue in mine accidents. When a refuge chamber is in refuge state, carbon dioxide scrubbing is an important function of the environmental control system in chamber. In this paper, a series of experiments about the power consumption, purification efficiency, bed thickness and other factors of carbon dioxide scrubber in mine refuge chamber were carried out to obtain the optimal operating way. Then these parameters were testified by life supporting experiment in enclosed chamber. [Copyright &y& Elsevier]