Energy harvesting from sediment microbial fuel cell to supply uninterruptible regulated power for small devices

Sediment microbial fuel cell (SMFC) is a bio‐electrochemical device that generates direct current by microbes present in the soil. The main drawback of SMFC is the low voltage and fluctuations. Therefore, a suitable scheme is required to obtain sufficient voltage with insignificant fluctuation. This paper proposes an energy harvester power management system (PMS) to get rid of low voltage and fluctuation problem of SMFC. The proposed PMS is composed of a dc‐dc boost converter, switches, and super capacitors. The boost converter (using LTC3108 IC) successfully steps up the voltage up to 2.658 V and provides it to the load for 1.5 minutes. Four SMFCs connected with four individual super capacitors and a single boost converter has been used to implement this scheme. In this strategy, the charging and discharging time of the SMFCs are controlled in such a way that the continuous power will be supplied to the load with the optimum number of SMFCs. This scheme is tested on an experimental setup. It is found that the energy harvester PMS supplies a continuous voltage of 2.658 V with the efficiency of 85.46%, which is sufficient to power for small devices such as remote environment sensors, temperature sensors, LED lighting, and submersible ultrasonic receiver.     

Experimental investigation on performance and emission characteristics of waste tire pyrolysis oil–diesel blends in a diesel engine

Disposal of waste tires is one of the most important problems that should be solved. This problem can be solved by considering waste tires for production of hydrogen or fuel for diesel engines. This paper presents the studies on the performance and emission characteristics of a four stroke, four cylinders, naturally aspirated, direct-injected diesel engine running with various blends of waste tire pyrolysis oil (WTPO) with diesel fuel. Fuel properties, engine performance, and exhaust emissions of WTPO and its blends were analyzed and compared with those of petroleum diesel fuel. The experimental results showed that WTPO–diesel blends indicated similar performance with diesel fuel in terms of torque and power output of the test engine. It was found that the blends of pyrolysis oil of waste tire WTPO10 can efficiently be used in diesel engines without any engine modifications.     

Conversion of waste tires to liquid products via sodium carbonate catalytic pyrolysis

This study deals with the pyrolysis of waste tires supplied from the transport industry. The base material of tire is latex, which is derived from natural rubber trees. Nowadays rubber (Hevea brasiliensis) is a fast-growing tropical tree crop, which is being cultivated for latex and ultimately for tire production. Waste tires can be recycled for energy and valuable materials in many ways; however tire burning is the most common practice for heat generation. In recent years, the catalytic conversion of waste tires through pyrolysis into liquid, solid, and gas products was investigated. Liquids product was produced from the catalytic pyrolysis of waste tire at high temperature (up to 600°C) using sodium carbonate (Na₂CO₃) as a catalyst. Thermo-physical characteristics of the produced liquid samples showed that up to 85% of the produced oil can be used in internal combustion engines. Gasoline and diesel fuel contents in the liquid products are 45% and 40%, respectively. The gas chromatographic (GC) analysis of the volatile fraction of pyrolysis products showed styrene (28.1%) and butadiene (10.7%) as dominant compounds. The gaseous phase includes C₁–C₄ hydrocarbons (4.8%) and the liquid phase includes C₅–C₈ hydrocarbons (6.5%) of the total products.     

Assessment of an Integrated Gasification Combined Cycle using waste tires for hydrogen and fresh water production

In this paper, an Integrated Gasification Combined Cycle (IGCC), which uses waste tires as a feedstock, for power, hydrogen and freshwater production is modeled using both EES and Aspen Plus software packages and assessed thermodynamically. During the study, it is found that tire gasification is a viable solution for leftover tire waste in the world. Furthermore, the novel integration of a multi effect desalination plant, driven by the excess heat from the combined cycle, further increases the systems plant efficiency. The hydrogen production to feed rate ratio is found to be 0.154, which is competitive to high-quality coals, such as Illinois No.6, making waste tires an excellent feedstock to produce hydrogen. The net power production output from the combined cycle is 14.5 MW which was driven by the excess thermal energy of the syngas. The water distillate production rate from the forward flow multi-effect desalination plant at the set conditions is found to be 0.99 kg/s. The systems overall energy and exergy efficiencies obtained are 58.9% and 57.4%, respectively.     

A review of the present situation and future developments of micro‐batteries for wireless autonomous sensor systems

Wireless sensor nodes (WSNs) are expected to play an increasing role in multiple application areas. These application areas vary from networks around the human body, sensors in smart tires, sensor networks that can control the safety and comfort levels throughout smart buildings, sensors that monitor the necessity for maintenance and sensors that track the conditions of food throughout the distribution chain. These wireless sensors need energy, which can be supplied by a battery or an energy harvester. However, even when an energy harvester is applied, energy storage is required to serve as energy buffer. In this review, the requirements that different types of wireless sensor networks impose on these batteries are explored, and several suitable types of batteries are reviewed. Moreover, the trends in battery development are described, and the future improvements are predicted. Finally, the possibilities are discussed to select a battery with properties that are matched to the requirements of the sensor nodes. Copyright © 2012 John Wiley & Sons, Ltd.     

Vibration energy harvesting in vehicles by gear segmentation and a virtual displacement filtering algorithm

In this study, vibration straight‐line displacements occurring during electric vehicle operations are changed into reversely rotating displacements and divided into small segments by a gear unit. Piezoelectric bending elements are used to form a cantilever beam–based energy feedback mechanism for converting vibration energy into electrical power within an allowable displacement range. A virtual vibration displacement filtering algorithm is proposed to effectively filter virtual displacements that cannot excite the energy harvester and generate electrical power. The average speed of the gear exciting the bender has an accuracy 30%, which is increased using this algorithm compared with 2 other algorithms and directly affects the accuracy of calculating the average power generated by the calculation of piezoelectric bending elements. Theoretical and experimental analyses are conducted for the impact of gear pitch on the regeneration power value by changing the gear pitch at a fixed driving speed. Experiments show that when a vehicle is operated at a fixed speed, the proposed method can be used to obtain the maximum average power of a single piezoelectric bending element through determination of a rational gear pitch. Specifically, when the test vehicle operated at 20 and 60 km/h, the gear pitch should have been 7 and 10 mm.     

Thermodynamics modeling of a novel nonpneumatic mechanical elastic wheel for predicting its mechanical–thermal behavior

An advanced thermodynamics model based on brush-type tire model was developed here to investigate the mechanical–thermal behavior of a novel nonpneumatic mechanical elastic wheel (ME-wheel), operating under rolling conditions. Herein, first, we proposed a novel brush-type tire physical model wherein the factors of realistic tire deformable and frictional behavior were introduced. Next, the heat generation and dissipation mechanism of ME-wheel was investigated to develop its thermal model. By combining the brush-type tire physical model and thermal model through the factors involving tire deformable energy loss and frictional power loss, we established this thermodynamics model to predict the temperature-dependent mechanical characteristics and corresponding thermal behavior of ME-wheel under rolling operating conditions. It is found that the computation results agree well with the obtained experimental data (tire static and dynamics testing), which demonstrated the capability of this model in precisely predicting the mechanical characteristics and thermal behavior of ME-wheel, particularly those designed for off-road vehicle under typical real operating conditions.     

Performance analysis of axisymmetric floating energy harvesters and influences of parameters and shape variation

This paper presents a novel axisymmetric floating energy harvester associated with hydraulic cylinders and gear rack mechanism to harness wave energy. The harvester collects energy in surge, heave, and pitch modes. The mathematical models for the harvester are developed to analyze the performance and the harvested power. The Pierson‐Moskowitz two‐parameter spectrum was utilized to model the incident waves. The retardation function for the radiation force and the added mass curve are fitted based on the least squares method. The irregular exciting force, the displacement, the velocity, and the power harvesting of the axisymmetric floating energy harvesters in three motion modes with irregular waves are simulated. The effects of harvester design parameters and the geometry shape variation of the submerged part on the wave‐exciting force, the displacement, the velocity, the harvested power, and the harvesting efficiency are investigated. Under the same output damping and the same parameters with the radius of 4 m, the submerged height of 4 m, the above‐water height of 2 m, and the center of mass of ?1 m, the cylinder wave‐exciting force in surge is highest among three shapes, the cone wave‐exciting force is highest among three shapes in heave and pitch modes, and the total harvested power and the efficiency of the cylinder‐shaped harvester are the highest among three different axisymmetric shapes, which are 40.521 kW and 62.96%, respectively. The harvested power and the efficiency differences between the cylinder and the cone are 1.571 kW and 2.4%, and the differences between the cylinder and the halfsphere are 8.543 kW and 13.28%. For the cylinder‐shaped harvester with the submerged height of 4 m, the above‐water height of 2 m, and the center of mass of ?1 m, when the radius increases from 3 m to 5 m, under the optimal output damping, the total harvested power and the harvesting efficiency increase by 38.811 kW and 35.83%, respectively. For the cylinder‐shaped harvester with the radius of 4 m and the above‐water height of 2 m, as the submerged part height increases from 2 to 4 m, the total harvested power and the harvesting efficiency increase by 15.776 kW and 24.51%, respectively. For the cylinder‐shaped harvester with the radius of 4 m, the submerged height of 4 m, and the above‐water height of 2 m, as the center of mass is reduced from 0 to ?1 m, the total harvested power and the harvesting efficiency rise by 15.153 kW and 23.54%, respectively.     

Modeling,control and power management of hybrid photovoltaic fuel cells with battery bank supplying electric vehicle

In this paper, modeling, control and power management (PM) of hybrid Photovoltaic Fuel cell/Battery bank system supplying electric vehicle is presented. The HPS is used to produce energy without interruption. It consists of a photovoltaic generator (PV), a proton exchange membrane fuel cell (PEMFC), and a battery bank supplying an electric vehicle of 3 kW. In our work, PV and PEMFC systems work in parallel via DC/DC converter and the battery bank is used to store the excess of energy. The mathematical model topology and it power management of HPS with battery bank system supplying electric vehicle (EV) are the significant contribution of this paper. Obtained results under Matlab/Simulink and some experimental ones are presented and discussed.     

Miniaturized piezoelectric energy harvester for battery‐free portable electronics

This paper describes a miniaturized energy harvester based on the interaction of two permanent magnets placed on both ends of a folded cantilever made with piezoelectric thin films. A unique design of the folded cantilever structures is developed to efficiently collect ambient vibrational energy over a wide frequency bandwidth for the operation of battery‐free electronic devices. The output performance of the two energy harvesters is observed to improve significantly through the use of the mutual coupling technique. The folded cantilever structure also demonstrates improved space efficiency compared with the conventional rectangular cantilever design. A wide frequency band and sufficient energy‐harvesting ability were successfully achieved by the optimally manufactured device. The maximum output power of the miniaturized energy harvester was 41.6 μW with an impedance of 0.3 MΩ. Furthermore, a pedometer was powered completely by the energy harvester without the need for any battery and external power source, demonstrating the potential of the proposed design for self‐powered electronics applications in a vibrational environment.     

Improvement of ultracapacitors-energy usage in fuel cell based hybrid electric vehicle

Hybrid electric power systems based on fuel cell stack and energy storage sources like batteries and ultracapacitors are a plausible solution to vehicle electrification due to their balance between acceleration performance and range. Having a high degree of hybridization can be advantageous, considering the different characteristics of the power sources. Some parameters to be considered are: specific power and energy, energy and power density, lifetime, cost among others. Ultracapacitors (UC) are of particular interest in electric vehicle applications due to its high-power capability, which is commonly required during acceleration. UCs are commonly used without a power electronics interface due to the high-power processing requirement. Although connecting UCs directly to the DC bus, without using a power converter, presents considerable advantages, the main disadvantage is related to the UC energy-usage capability, which is limited by constant DC bus control. This paper proposes a novel energy-management strategy based on a fuzzy inference system, for fuel-cell/battery/ultracapacitor hybrid electric vehicles. The proposed strategy is able to control the charge and discharge of the UC bank in order to take advantage of its energy storage capability. Experimental results show that the proposed strategy reduces the waste of energy due to dynamic brake in 14%. This represents a reduction in energy consumption from 218 Wh/km to 192 Wh/km for the same driving conditions. By using the proposed energy management strategy, the estimated fuel efficiency in miles per gallon equivalent was also increase from 96 mpge to 109 mpge.     

System design and control strategy of the vehicles using hydrogen energy

This paper presented a system design review of fuel cell hybrid vehicle. Fuel supply, hydrogen storage, DC/DC converters, fuel cell system and fuel cell hybrid electric vehicle configurations were also reviewed. We explained the difference of fuel supply requirement between hydrogen vehicle and conventional vehicles. Three different types of hydrogen storage system for fuel supply are briefly introduced: high pressure, liquid storage and metal oxides storage. Considering of the potential risk of explosion, a security hydrogen storage system is designed to restrict gas pressure in the safe range. Due to the poor dynamic performance of fuel cells, DC/DC converters were added in hybrid vehicle system to improve response to the changes of power demand. Requirements that in order to select a suitable DC/DC converter for fuel-cell vehicles design were listed. We also discussed three different configurations of fuel-cell hybrid vehicles: “FC + B”, “FC + C”, and “FC + B + C”, describing both disadvantages and advantages. “FC + B + C” structure has a better performance among three structures because it could provide or absorb peak current during acceleration and emergency braking. Finally, the energy management strategies of fuel cell and were proposed and the automotive energy power requirement of an application example was calculated.     

Performance evaluation of fuel cell fed electric vehicle system with reconfigured quadratic boost converter

The performance evaluation of 1.26 kW fuel cell fed electric vehicle system with reconfigured Quadratic Boost Converter along with the neural network based maximum power point tracking algorithm is presented in this paper. The acceptance of EV in modern society is relevant for the creation of pollution free environment. The main reason for creation of excessive pollution is transportation by the mode of roadways, with the own internal combustion engines by using crude oil as primary energy source. In this paper, a 1.26 kW Proton Exchange Membrane Fuel Cell (PEMFC) fed electric vehicle is designed in MATLAB/Simulink environment. To integrate PEMFC to brushless DC (BLDC) motor are configured Quadratic Boost Converter is designed for high static converter voltage gain. The performance of the proposed EV system is analysed with perturb and observer method and neural network based MPPT control techniques and obtained results are compared at different fuel cell input temperature conditions with respect to different time periods.     

煤矿胶轮车用柴油机冷却系统热平衡分析研究

目前煤矿快速开采和连续作业使得煤矿胶轮车用柴油机热负荷越来越高,因此对其冷却性能的要求也就越来越高,为提高柴油机冷却系统的性能,对其进行匹配研究和分析计算,在原冷却系统的基础上进行了改造,提高了系统散热能力,减少整体功率消耗,解决了原发动机系统出现的高温问题。该方法的研究和应用在柴油机热平衡领域具有理论和现实双重意义。     

Development of an ocean wave energy harvester with a built‐in frequency conversion function

The research develops a novel harvester associated with a built‐in frequency conversion device to harness energy from ocean waves based on the piezoelectric effect. The developed harvester consists of 2 generators driven by rotational motions converted from vertical motions by a rack and pinion actuator. The generator has a rotator with a magnetic bar attached to its blade tips and a stator. By this innovative design, the harvester is capable of converting ocean waves with low frequencies to mechanical vibrations with higher excitation frequencies of the piezoelectric transducer for increasing its energy conversion efficiency. A corresponding mathematical model for the harvester is developed to evaluate the generated power. The simulation results show that the generated power increases with increases in the ocean wave height, number of magnetic bars and decreases in the wave period, the distance between 2 opposite magnetic bars, and harvester's submerged part height. The power output is realized up to 260 W with the height, length, and width of the harvester being 1m × 1m × 1m, at the ocean wave height and period being 2 m and 7 seconds, respectively.     

Electromagnetic energy harvester for monitoring wind turbine blades

The long composite blades on large wind turbines experience tremendous stresses while in operation. There is an interest in implementing structural health monitoring (SHM) systems inside wind turbine blades to alert maintenance teams of damage before serious component failure occurs. This paper proposes using an energy harvesting device inside the blade of a horizontal axis wind turbine to power a SHM system. The harvester is a linear induction energy harvester placed radially along the length of the blade. The rotation of the blade causes a magnet to slide along a tube as the blade axis changes relative to the direction of gravity. The magnet induces a voltage in a coil around the tube, and this voltage powers the SHM system. This paper begins by discussing motivation for this project. Next, a harvester model is developed, which encompasses the mechanics of the magnet, the interaction between the magnet and the coil, and the current in the electrical circuit. A free fall test verifies the electromechanical coupling model, and a rotating test examines the power output of a prototype harvester. Copyright © 2013 John Wiley & Sons, Ltd.     

Simulation research on a novel control strategy for fuel cell extended-range vehicles

Adapting to urban transportation and emission reduction in China, fuel cell extended-range commercial vehicles are advocated and studied, which have the advantages of no pollution and long continued driving mileage. According to the features of fuel cell extender and characteristics of the powertrain system of the electric commercial vehicle, the design principle of the extender control strategy is determined in this paper, in order to improve the power and economic performance. A simulation platform for fuel cell plus electric vehicles was established. By comparing and analyzing the characteristics of on-off control strategy, power following control strategy and fuzzy logic control strategy, an on-off power following control strategy is put forward and built which is used for extender controller, and a fuzzy algorithm of following control strategy is studied. By Simulating and analyzing on the platform, the results show that the power following fuzzy algorithm can improve the power performance with the 8.9s accelerating time (0–50 km/h) and better total mileage continued 286.7 km for the powertrain system of fuel cell extended-range commercial vehicles. The research in this paper provides a basis for the in-depth study of the energy management of electric vehicles.     

Influence of temperature and electrolyte on the performance of activated-carbon supercapacitors

For hybrid electric vehicle traction applications, energy storage devices with high power density and energy efficiency are required. A primary attribute of supercapacitors is that they retain their high power density and energy efficiency even at −30 °C, the lowest temperature at which unassisted starting must be provided to customers. More abuse-tolerant electrolytes are preferred to the high-conductivity acetonitrile-based systems commonly employed. Propylene carbonate based electrolytes are a promising alternative. In this work, we compare the electrochemical performance of two high-power density electrical double layer supercapacitors employing acetonitrile and propylene carbonate as solvents. From this study, we are able to elucidate phenomena that control the resistance of supercapacitor at lower temperatures, and quantify the difference in performance associated with the two electrolytes.     

Analytical and numerical fluid–structure interaction study of a microscale piezoelectric wind energy harvester

In this paper, an analytical approach and two numerical models have been developed to study an energy‐harvesting device for micropower generation. This device uses wind energy to oscillate a cantilevered beam attached to a piezoelectric layer for generating electric energy output. The analytical approach and the first numerical model consider the fluid–structure interaction phenomenon in the harvester performance. The equations governing beam oscillations and airflow have been coupled to a set of four differential equations in the analytical approach. This set of equations has been solved to determine the beam deflection and the air pressure variation with time. The numerical methods have been conducted by employing a commercial software. The results of the analytical method and the first numerical model have been compared in different working conditions, and their credibility has been discussed. In the second numerical model, the electromechanical performance of the piezoelectric material has also been incorporated in the harvester device analysis. This model has been verified against experimental data for the output voltage and power of the device available in the literature. Finally, the effect of different geometrical parameters has been studied on the harvester performance, and suggestions have been made to improve the harvester efficiency.     

Energy conservation from systematic tire pressure regulation

The majority of US drivers do not consistently monitor the tire pressures in their vehicles. The 2000 TREAD Act, which requires automakers to gradually provide tire pressure monitoring systems for vehicles sold in the US will correct this problem for new vehicles. This law does not impact the problem in previously deployed vehicles, which have a turnover time of ∼20 years. A solution is provided here to address under-inflated tires on the current 220 million vehicles and the concomitant wasted energy due to increased rolling resistance in the US automobile fleet. This communication reports on a preliminary study of tire pressures in randomly chosen vehicles, which were undergoing oil changes at a combined retail/auto-care facility. The study indicates that substantial benefits would accrue if car care facilities systematically offered complimentary tire pressure checks with oil changes including: (i) increased safety by decreasing all crashes and saving more than 100 lives per year, (ii) reduced petroleum consumption by over a billion gallons/year, which would (iia) provide over $4 billion in economic savings for US consumers that could in part be recouped in retail/auto-care facilities, (iib) reduce greenhouse gas emissions by 13.5 million tons and automobile pollution and (iic) enhance national security.