High-pressure Compressed Air Research Articles

Energy and exergy analysis of a novel advanced adiabatic compressed air energy storage hybridized with reverse osmosis system

Providing sustainable energy and ensuring a reliable supply of clean freshwater are two critical and interconnected challenges. This paper introduces an innovative approach that combines an advanced adiabatic compressed air energy storage system with a reverse osmosis system to enhance energy storage efficiency and freshwater production. During the charging phase, compressed air is injected into a tank filled with saltwater. Simultaneously, the high-pressure compressed air forces saltwater into the reverse osmosis modules. In the discharge phase, water is pumped into the compressed air storage tank to maintain a nearly constant tank pressure. The results demonstrate the advantages of this hybrid system over separate adiabatic compressed air energy storage and reverse osmosis systems producing the same amount of fresh water. Specifically, the proposed hybrid system achieves an 11.3 % increase in generated power during discharge and a 1.2 % improvement in round-trip efficiency. Reducing the compressed air tank capacity from 1200 to 800 m3 accentuates the hybrid system's superiority, increasing the round-trip efficiency difference between the hybrid and separated systems to 5.6 %. By selecting an appropriate compression ratio, a round-trip efficiency of 61.9 % can be achieved. Furthermore, an exergy analysis highlights the compressed air storage tank and turbines as the most exergy-destructive components of the system.

Design and Development of a New 0.5m Hypersonic Wind Tunnel Facility at Indian Institute of Science

This paper describes the realization of a 0.5m hypersonic wind tunnel, second largest of its kind in India, at the High Speed Wind Tunnel Complex at Indian Institute of Science (IISc), Bangalore. The project was fully funded by the Aerodynamics Panel of AR & DB. There were two major activities associated with the project. One of them pertains to the "Strengthening of the existing 0.3m Hypersonic Wind Tunnel "(originally built in 1985) by adding a new high pressure air compressor, a cascade of high pressure air storage tanks, vacuum pumps and vacuum tanks and another related to establishing "an Additional 0.5m Hypersonic Wind Tunnel Leg". Preliminary commissioning trials of the new facility at low stagnation pressures were conducted in October 2013. Subsequently several hypersonic blow downs were carried out on a variety of models at Mach 8.0. Pitot probe measurements performed in the test section confirmed that the flow Mach number was close to Mach 8.0. The total run time measured was around 10 seconds. Thus, a large 0.5m hypersonic wind tunnel was indigenously designed, developed and commissioned in about 30 months at a cost of Rs.6 Crores. The facility was inaugurated by Prof. R. Narasimha in the presence of a large gathering of leading aerospace scientists in the country, on 8th April 2014.

Mechanical behavior of different fiber lengths mix-proportions carbon fiber reinforced concrete subjected to static, impact, and blast loading

Impact and blast wave loadings act as high instant energy and might cause damage to reinforced concrete infrastructures. This research aims to investigate the effect of using different length proportions of carbon fiber on the mechanical behaviors of concrete. Moreover, in this study, original carbon fiber and sizing-removed carbon fiber were added into concrete with different mix-proportions. The sizing on the carbon fiber surface was removed by using heat-treated method. In addition, the carbon fiber was dispersed by a high-pressure air compressor. Lengths of 12 mm and 24 mm carbon fibers were used in different mix-proportions to find the highest mechanical strength of carbon fiber reinforced concrete (CFRC) under a 1% fiber-to-cement weight ratio. Compressive, flexural, and impact tests were conducted on CFRC specimens. The CFRC specimen with 50% 12 mm and 50% 24 mm sizing-removed carbon fiber attained the highest impact resistance, and it also had the best performance under blast wave loading compared with the other CFRC specimens. The broken CFRC specimens were examined by an optical microscope to identify the failure mode of the carbon fibers in CFRC specimens. The addition of 50% 12 mm and 50% 24 mm sizing-removed carbon fiber can significantly improve the compressive and flexural strength of reinforced concrete.

Justification of parameters of the process of injecting compressed air into the piston air spring in the boom machine working equipment

While lifting a payload, boom machines perform a useless job to overcome gravitational forces of the working equipment gravity force. The piston spring, injected with compressed air to a pressure of pw =10-15 MPa, ensures balancing gravitational forces of gravity during vertical movements and eliminates the indicated disadvantage. The piston air spring, independently mounted in the boom machine working equipment, represents an energy saving unit. A detailed analysis of physical processes of obtaining high-pressure compressed air for the injection into the air spring has been conducted, new solutions have been obtained, connected with the technology of air compression to high pressure, satisfying definite design requirements.

Effects of intake high-pressure compressed air on thermal-work conversion in a stationary diesel engine

ABSTRACT Compressed air energy storage is one of the green energy storage and conversion systems. In this work, the compressed air was directly supplied to a stationary diesel engine to investigate the effects of compressed air characteristics on the process of thermal-work conversation in diesel engines. Then, the thermal efficiency of supplying compressed air to a diesel engine is compared against a simple hybrid system that consists of a compressed air engine and a baseline diesel engine. The results indicate that the compressed air affects the thermal work conversion of diesel engine. The gross indicated mean effective pressure is being used to quantify the in-cylinder pressure work that transferred to the piston motion only for the combustion and expansion strokes, which increases as the pressure of compressed air increases and decreases as the temperature of the compressed air increases. The gross indicated thermal efficiency that represents the ability of thermal-work conversion is maximum at intake pressure of 300 kPa and intake temperature of 303 K with a value of 44.3%, which is 19.7% higher than that of the baseline diesel engine with 100 kPa intake pressure and 303 K intake temperature. The diesel engine using compressed air shows 6.64% higher overall efficiency than the simple hybrid system. The soot emissions increase with increasing intake pressure, and decrease with increasing intake temperature. As the intake temperature increases, NOx emissions increase. As the intake pressure increases, NOx emissions first decrease and then increase.

Study of pneumatic sources of elastic waves for marine seismic exploration

An extensive use of geophysical methods necessitates the development of new methods and improvement of existing methods for seismic exploration to provide reliable data on the structure of the environment in difficult geological conditions. Therefore, it is especially relevant to solve the problems arising in marine petroleum geophysics, which require constant improvement of the methodology and technology of work, and the development and implementation of the advanced seismic equipment. Pneumatic sources that use compressed air as a working medium are among the most effective non-explosive sources for marine seismic exploration. Pneumatic sources exhibit high-energy characteristics, reliability and versatility. Compressor equipment that provide pneumatic sources with high-pressure compressed air is relatively easy to embed into the marine vessel’s power system. The above requires the development and improvement of theoretical methods for studying dynamic problems of a liquid half-space with buried sources of various types. A theoretical description of the formation of an elastic signal in water is given in a number of works. However, the authors of these works do not perform the analysis of gas transportation. The paper considers a number of characteristics of gas flow at a subsonic speed along the high-pressure hose from a vessel’s compressor unit to a pneumatic source. The airflow rate in the receiver-pneumatic source system is determined, and the friction force at a quasi-steady isothermal mode of gas flow is calculated. The paper presents recommendations for planning geophysical works.

Design and Verification Test of the Primary and Secondary Stage Compression Gap Size of Miniature High Pressure Air Compressor

Aiming at the prominent problem of the primary and secondary pistons hitting the cylinder head in the current miniature high-pressure three-stage air compressor, a design study on the size of the primary and secondary compression gap is carried out. Through the theoretical force analysis of the connecting rod, the force situation of the connecting rod at the top and bottom dead centers is obtained. The three-dimensional models of connecting rod and cylinder are established based on SolidWorks software, and the three-dimensional models are simplified. Based on Ansys Workbench software, the connecting rod and cylinder models are pre-processed, model discretized and post-processed. The structural statics and steady-state thermal comprehensive analysis of the connecting rod at the upper and lower dead points and the steady-state thermal analysis of the cylinder under working conditions are completed. Through analysis, the total axial deformation of the connecting rod and the total axial deformation of the cylinder under high temperature and high speed working conditions are obtained. According to the simulation analysis results, the first and second compression gap size is designed. Based on the design results, ten sets of air compressors are tested for dimensional design verification. The test results show that the air compressors of each test group can complete the charging requirements within the specified time, and there is no phenomenon of piston hitting the cylinder head, indicating the size design reliability.

Degrader Analysis for Diagnostic and Predictive Capabilities: A Demonstration of Progress in DoD CBM+ Initiatives

Abstract This paper presents a modified reliability centered maintenance (RCM) methodology developed by The Applied Research Laboratory at The Pennsylvania State University (ARL Penn State) to meet challenges in decreasing life cycle sustainment costs for critical Naval assets. The focus of this paper is on the requirements for the development of the on-board Prognostics and Health Management (PHM) system with a discussion on the implementation progress for two systems: the high pressure air compressor (HPAC), and the advanced carbon dioxide removal unit (ACRU). Recent Department of Defense (DoD) guidance calls for implementing Condition Based Maintenance (CBM) as an alternative to traditional reactive and preventative maintenance strategies that rely on regular and active participation from subject matter experts to evaluate the health condition of critical systems. The RCM based degrader analysis utilizes data from multiple sources to provide a path for selecting systems and components most likely to benefit from the implementation of diagnostic and predictive capabilities for monitoring and managing failure modes by determining various options of possible CBM system designs that provide the highest potential ROI. Sensor data collected by the PHM system can be used with machine learning applications to develop failure mode predictive algorithms with greatest benefit in terms of performance, sustainment costs, and increasing platform operational availability. The approach supports traditional maintenance strategy development by assessing the financial benefit of the PHM technology implementation with promising potential for many industrial and military complex adaptive system applications.

Rectosigmoid perforation after high-pressure air jet exposure: A case report

Rationale: Colonic barotrauma induced by high-pressure air compressors has been reported more frequently these days due to the widespread use of air compressors in industries. Such enormous pressure into the rectum can lead to devastating injuries. Patient’s concern: A 35-year-old male was referred to our emergency department with an alleged history of directing high pressure compressed air jet towards the anus. There was diffuse subcutaneous emphysema over the neck, chest, abdomen, and extremities, and he presented with hemodynamic instability and respiratory failure. Diagnosis: Rectosigmoid perforation due to exposure to high-pressure air jet causing tension pneumoperitoneum, pneumomediastinum, pneumothorax, and extensive subcutaneous emphysema. Intervention: In view of tension pneumoperitoneum, urgent percutaneous needle decompression was performed using 16 G needle, 5 cm superomedial to the anterior superior iliac spine. The gush of air was released along with reduction in abdominal distension and improvement in hemodynamics. Outcome: The patient succumbed two days later due to septic shock. Lessons: This case highlighted the importance of promoting education about work safety among industrial workers especially in developing countries like India.

Development of soil improvement system using high-pressure compressed air II : Practice cases and observation of the effects

Development of soil improvement system using high-pressure compressed air II : Practice cases and observation of the effects

Pneumatic Colorectal Injury Caused by High Pressure Compressed Air.

The pneumatic colorectal injury caused by high pressure compressed air are rare and can be fatal. Herein, we present a case of 45-year-old male who developed sudden onset of severe abdominal pain after cleaning the dust on his pants with high pressure compressed air gun dust cleaner. Emergent exploratory laparotomy was done which findings are a huge rectal perforation with multiple serosal and subserosal tear in sigmoid to splenic flexure of colon. Anterior resection with left hemicolectomy, and temporary transverse colostomy was performed. Postoperative course was uneventful. Recently, prognosis is generally favorable because of prompt diagnosis and emergent surgical management.

왕복동식 미소 유량 공기압축기의 설계 및 성능예측 이론연구

In this theoretical study, a design and performance analysis theory of a micro flowrate and high pressure air-compressor is developed. The governing equations are from the gas state equation and fluid dynamic theories because the working fluid in the air compressor is in a gas phase. A case study was conducted to design a reciprocating type of air compressor which the target performance was 0.6liter/min in the volume flowrate with 5atg in air pressure at 1,600rpm rotational speed. Geometrical size of the model air compressor designed is 10mm in stroke, 20mm in bore with 4.79 compression ratio. From the performance analysis of the model compressor, it was found that the air volume flowrate produced was 0.6liter/min with 5.81atg in pressure. The design theory of a micro-size high-pressure air compressor developed in this study is expected to be very useful design tools in NANO technology industry.

Experimental study of analogue vent erosion towards nozzle shapes

Volcanic vent shapes evolve over the course of an explosive eruption, as the high-pressure ejecta erode the solid conduit walls. The changing shape affects the fluid behavior of the expelled gases, potentially the plume rise, column collapse, and the type and amount of accidental debris ejected. Field observations of evolving vent shape are difficult or impossible. While the mechanics of this process have been studied numerically, almost no laboratory studies have examined these behaviors. Thus, a series of test samples was manufactured using 3D printing techniques, which were eroded using high-pressure compressed air. Four material combinations were considered, using stainless steel and alumina powders consolidated with binder concentrations of 16% and 38%. Material properties were evaluated using compression testing, while the erosion behavior was studied through high-speed visualization and pressure measurements with identical samples at constant inflow conditions. In all cases, the erosion showed an initial rapid erosion of the vent exit, followed by quasi-steady state conditions. All samples produced converging/diverging nozzle shapes, with exit areas increasing by 1.5 to 6 times, depending on the sample properties. Behavior correlated strongly with binder concentration, as low-binder materials had significant increases in nozzle area. When using high-density particles, these weaker samples disintegrated due to particle abrasion from higher kinetic energy impacts. The nozzle shapes produced supersonic exit conditions, with Mach numbers from 1.48 to 2.51 for the various samples. However, exit pressures were not balanced, suggesting that the optimum is not the isentropic, pressure-balanced shape previously postulated.

Severe Traumatic Pneumothorax, Pneumomediastinum and Pneumoperitonium

Clinical Image A 49 year old female presented to the emergency department complaining of dyspnea with chest tightness .The symptoms began after her husband put the nozzle of high-pressure air compressor into her mouth with violent behavior 2 hours ago (Figure 1). Onexam, the vital sign was normal despite of respiratory rate 24 breaths per minute, with oxygen saturation of 97% on room air. Face swelling and oral laceration were noted (Figure 2). Massive subcutaneous emphysema and crepitus over chest and neck area were observed. The chest X-ray showed massive bilateral pneumothorax, penumomediastinum with subcutaneous emphysema over chest wall and neck (Figure 3). The CT confirmed the diagnosis of pneumoperitonium and left pneumo-retroperitoneum (Figure 4). The bronchoscopy revealed no evidence of tracheal bronchial tree injury (Figure 5) and panendoscopy revealed any esophagus injury (Figure 6). The 28-Fr chest tubes were inserted into both sides. She was discharged nine days following admission without consequences

Simuling a Compressed Air Energy Storage For a Net Zero Energy Building in Tropics

Facing the demand in electricity for houses or buildings provided by mean of photovoltaic panels is relatively tricky, especially because of the stochastic character of the solar radiation. There exists some solutions in terms of storage and among them, the one consisting in converting electricity in high-pressure compressed air seems promising. This option is under investigation in a building of teaching classes at Reunion University (a French island situated in the Indian Ocean, at the east of Madagascar. The aim in terms of consumption is 25 kWhPE.m-2.year-1 leading, if possible to a NetZEB (Zero Energy Building). So, it has been envisaged to produce the electricity by mean of PV panels, to consume the major and to store the extra production in order to be used at night and during lower shinning periods. The solution that has been investigated consists in compressing air in high pressure storage tanks and to produce electricity later thanks to a turbine. A dynamic numerical model has been built, considering a specific given load profile and local climatic data in order to estimate the production. The whole system depends mainly on the PV panel area, the storage tank volume and the pressure range. The objective is to reduce the amount of energy provided by the external network to the minimum leading to the maximum autonomy of this system. First results have been obtained and are explained in a last part, in terms of pressure and power evolution.

Optimization and implementation of a foam system to suppress dust in coal mine excavation face

Foam technology is more efficient than water sprays for dust control in coal mines, but the traditional foam system is complex and poses problems related to foam production and spraying application, with high water consumption, unstable equipment and relatively low utilization efficiency of foam. This paper describes an optimized foam system which overcomes these disadvantages. The proposed foam generator has a self-suction unit that uses a turbulent-flow water jet to automatically draw in ambient air and foaming agent, thereby eliminating the need for compressed-air hoses and pipes. As well as simplifying the system, it solves the current problem of water backflow created by high-pressure compressed air. A refined foam spraying structure was developed for use in conjunction with an operating roadheader as it produces and diffuses dust. The structure consists of foam distribution supports and arc-fan nozzles. It can produce a more focused, continuous and uniform coverage at the source of the dust. The optimized system consumes less water and foaming agent, and achieves greater dust-suppression efficiency than methods in current use.

Pneumatic power plant as an alternative source of ecologically clean domestic energy

The solution of the problem of unstable parameters of the output voltage of wind power plants because of the inconstancy of wind flow, limiting the scope of their application based on the transition to the development of pneumatic power plant, containing energy accumulators in the form of high-pressure compressed air tanks in its structure is considered in the paper. Concrete design of low-capacity pneumatic power plant is proposed. The issue of calculating and selecting the sizes of energy accumulators in the form of high-pressure tanks, taking into account certain intervals of the wind flow is studied. Duration of continuous operation of the electrical load with power of up to 1 kW at various energy accumulator capacities is determined. The choice of power of the load consumed from the condition of its uninterruptible power supply with the presence of constraints on the sizes of the energy accumulators, their charging rate, installed capacity of the power generator, type size of the wind wheel, as well as constancy of the wind flow strength and speed are shown.

Modeling of a Compressed Air Energy Storage Connected to a PV Field for NZEB in Tropics

Producing electricity for houses or buildings often provided by mean of photovoltaic panels is relatively tricky especially because of the stochastic character of the solar radiation and of the storage influence. There exist some solutions and among them, the one consisting in converting electricity in high-pressure compressed air seems promising. Due to a refurbishing project of teaching classes at Reunion University (a French island situated in the Indian Ocean, at the east of Madagascar), this option is under investigation in parallel to reducing consumption in the building. The aim in terms of consumption is 25 kWhPE.m-2.year-1 leading, if possible to a NetZEB (Zero Energy Building). So, it has been envisaged to produce the electricity by mean of PV panels, to consume the major part and to store the extra production in order to be used at night and during lower shinning periods. The solution that has been investigated consists in compressing air in high pressure storage tanks (from a few tens to two hundred bar) and to produce electricity later thanks to a turbine. Nevertheless, the system remains electrically connected to the external network if extra electricity is required by the building and while the turbine is under operation or if too much electricity is produced and not being able to be stored instantaneously. A dynamic numerical model has been built, considering a specific given load profile and local climatic data in order to estimate the production.

2A2-P03 高圧コンプレッサと空気圧回生システムを搭載した自立型空気圧駆動ロボットBIRDLEGの開発と跳躍動作実現(アクチュエータの機構と制御(2))

Pneumatic robots have structural softness which is an important element when robots work in living environments of humans. In addition, pneumatics is one of the approaches to realize jumping, running, walking and so on, which are performed by animals and humans. The self-contained pneumatic robot we previously developed has a commercial super-small air compressor, which generates insufficient pressure for dynamic motions such as jumping. To solve this problem we designed and developed super-small high-pressure air compressors. As an additional method of improving the maximum pressure, we tested to increase the intake pressure by using the compressed air stored with a regenerative air pressure system. We verified the efficacy of supercharging. We also developed a self-contained pneumatic robot BIRDLEG with the new super-small high-pressure compressor and the regenerative air pressure system. We verified the validity of the design concept for self-contained pneumatic robots by realization of jumping on BIRDLEG without any external air pressure source.

An agent-based framework for collaboration among critical mechanical devices working in a cluster

Critical mechanical devices, such as high-pressure air compressors, are crucial for industrial production. Critical mechanical devices are independently distributed devices that work in a cluster, but have high power requirements and need large amounts of space. Thus, the efficient control and coordination of a cluster of critical mechanical devices to achieve task goals is beset with difficulties. Motivated by an example of high-pressure air compressors in a cluster, this paper proposes an agent-based framework for realizing collaboration among critical mechanical devices that work in a cluster. The proposed agent-based framework endows critical mechanical devices with abilities such as autonomy, interaction and collaboration. The framework comprises three core components: (i) an agent-based control approach to the design of critical mechanical device agents to create autonomy; (ii) a type of critical mechanical device agent communication language to create interaction among critical mechanical devices; and (iii) a total working time-based collaboration algorithm that fully considers the physical characteristics of critical mechanical devices to create collaboration among critical mechanical device clusters. A type of critical mechanical device agent controller is implemented using the proposed approach. The agent-based framework has been successfully applied and evaluated in a real-world project. The results obtained in that case study show that the proposed framework can achieve collaboration among critical mechanical device clusters allowing them to realize their predefined goals efficiently and safely.