In this research, thermal decomposition characteristics of cellulose with electron injected air were investigated in a laboratory scale reactor based on the principle of the groundbreaking organic substance reduction device ERCM (Earth-Resource-CeramicMachine), which was developed by a Japanese venture company. A 12 V voltage electron generator as the key part, was adopted to inject electrons into the air for accelerating the thermal decomposition of carbonaceous materials during the ERCM process. A modified fixed bed reactor was adopted to investigate the effects of different parameters including the on/off of electron injection into the air and the thermal decomposition temperatures (350-500O C) on the decomposition degree (volume reduction rate) and the syngas generation of pure cellulose. It was found that the thermal decomposition reaction was more accelerated with the electron-ON case than that with the electron-OFF case. In addition, it was shown that the volume reduction rate of cellulose in the electron-ON case was higher by 4.4% to 18.3% than that in the electron-OFF case. These results suggest that electron injected air may accelerate the thermal decomposition of solid wastes.
Hydrate decomposition is an endothermic reaction. The exploitation effect is closely related to the heat transfer properties in hydrate deposits. Based on the results of experiment and simulation with depressurization (PD), depressurization combined with wellbore heating (DH) and huff and puff method (HP), this paper mainly studies the heat transfer from the boundaries (QB), the heat consumption by hydrate decomposition (QH), the heat absorption by the porous sand (QS), and the heat loss (QL) to optimize the production methods. The results show that a limited amount of QL is caused by the heat transferred to the water bath in HP. In addition, the heat transferred from the water bath can offset the QS, which is the main component of QL in HP. Thus, the best heat utilization is seen in this method. PD shows its obvious weakness in hydrate recovery duration, although it only uses the QB for hydrate decomposition. For DH, the amount of the lost heat is the largest among the three methods, and the majority of QL is caused by the heat from wellbore heating transferred to the ambient environment. Thus, the heat utilization in this method is the worst. For the optimization of the exploitation method, it is of great importance to decrease the heat transferred to the surrounding environment.
Increasing penetration rate of renewable energy in distribution network (DN) require effective measure for self-balancing. Considers the profit of multi-investors with distributed energy resources (DERs) in a district DN, this paper proposed an incentive-based optimal operation method. This is a win-win situation for both the utility grid and the investors of DERs. On the one hand, the demand fluctuation and reverse power flow is reduced to delay the investment of gird expansion; the other part is the multi-investors can benefit from the coordinated response process. The case study demonstrates the effectiveness of the proposed approach.
To further advance low NOx pulverized-coal (PC) ignition theory, guide the parameter design of PC burner of bias combustion technologies and enable the related numerical simulation work, combustion experiments for an Indonesian coal were conducted in a 250-kW pilotscale Bias Combustion Simulator (BCS); multiple research means of combustion temperatures and flame spectra were used. The effects of initial Pulverized Coal Concentration (PCC) on the standoff distance, ignition mode and continuous flame region of bias PC jets in a reducing atmosphere were investigated. The results indicate that with increasing initial PCC for bias PC jets in the experiments, the standoff distance gradually decreased, the peaks of subsequent combustion temperature and light emission intensity gradually increased, the continuous flame regions became gradually concentrated, the flame stability became gradually stronger, and the ignition characteristics gradually improved. The initial PCCs changed the ignition mode of bias PC jets; there was homogeneous– heterogeneous combined ignition mode at initial PCCs of 0.33 and 0.41kg/kg; there was homogeneous ignition mode at an initial PCC of 0.53kg/kg. At different initial PCCs, the continuous flame region of bias PC jets leant obviously in the direction of the fuel-rich jet.
Electric vehicles (EVs) have been viewed by many as a method to reduce greenhouse emissions, operate mobility efficiently, and decrease energy consumption. The limited driving range is a huge challenge to promote the popularization of EVs. The wireless charging lane can charge EV when it travels, thus can decrease the driving range anxiety of the driver. In this paper, we propose a new wireless charging scheme which combines the signalized intersection and partial wireless charging lane. We develop an eco-driving control strategy for EVs at intersections with wireless charging. The numerical results show that the wireless charging scheme with the eco-driving control strategy can increase the driving range and decrease the travel cost.
This paper proposes the use of a heavy ventilated wall to store natural energy and improve heating performance. An ideal numerical model was setup, and the thermal performance and annual heating contribution under different heating power, building insulation, airtightness and climates were explored by case studies. It is found that the ventilated wall with heat source has the potentials for creating a stable thermal environment, and also contributes to reducing building heating load. The initial findings can help engineers to develop design proposals for building envelops with an active heat source at the early design stage.
In order to improve the efficiency of the existing plunger grouting pump, a new grouting pump based on Wankel engine is proposed. The structure, principle and mathematical model of the Wankel pump were proposed. The efficiency of plunger pump and Wankel pump are analyzed, and the calculation formulas of mechanical, volumetric and hydraulic efficiency of Wankel pump are proposed. The efficiency characteristics of the wankel pump were studied experimentally, and a plunger pump and a Wankel pump of the same power are selected to compare their working efficiency under different working conditions. In general, ηm and ηv increased with increasing n until the load on the shaft was too large. At the same n, The smaller the outlet, the lower the efficiency. When the outlet is a, b and c, the wankel pump test data at n of 190 r/min, 160 r/min and 140 r/min is optimal. When the outlet is big such as a and b, Wankel pump performs higher flow and higher efficiency. However, when the outlet is small such as outlet c, plunger pump performs higher pressure and stable flow and efficiency.
Two high-pressure reactors with effective volumes of 1.0 L and 3.3 L were employed to investigate the dynamic behavior of methane hydrate formation and dissociation induced by depressurization with the aim of elucidating the difference in production behavior and developing the scaling criteria. Based on the experimental results, to synthesize aqueous-rich MHBS of the same saturations, the amount of hydrate-formers and the sandy media should strictly adhere to the volume ratio. Increasing the sample size of MHBS resulted in 20.7% increase in gas recover ratio and 53.8% decrease in water recovery ratio under bottom hole pressure of 4.0 MPa. Heat transfer direction were similar from outer boundary inward to the core center. Understanding the effect of scaling on production profile could shed light on better experimental design and possibly field production tests.
Butanol is a second-generation biofuel which obtained from the biomass feedstock sources to improve the fuel properties and performance of the recent fuels. However, there are certain grey aspects in the combustion characteristics of butanol blends in various operating speeds and loads. This previous work investigated the use of mineral diesel (D), palm biodiesel (B), butanol (10%)-diesel (90%) (DBu10) and butanol (10%)-palm biodiesel (90%) (BBu10) fuels. The objectives of this study are to investigate the cyclic combustion variations of cylinder pressure profiles and peak cylinder pressure, Pmax and analyse the combustion stabilities using recurrence plot (RP) on tested fuels using a diesel engine. The results showed that higher peak cylinder pressures were observed for butanol blends with full load at 1100 rpm. Higher cylinder pressure cyclic variability occurred at high load and speed for all test fuels, especially DBu10 with higher COVPmax values. Thus, in this case, DBu10 produced the most chaotic combustion irregularities and higher cyclic variations for the time series in those conditions. In conclusion, cylinder pressure variations in the time series were found to be affected by the fuel composition of butanol in the blends and types of fuel in engine operation.
After a major event affecting the world economy, oil prices tend to fluctuate due to the event in the next few months or even years. It can be seen that oil prices may have long-term correlation. In the processing of time series, the traditional ARMA model cannot accurately describe long memory, which leads to the deviation of parameter estimation during the modeling process. In order to better describe the long memory in the time series, this paper establishes the ARFIMA model to perform fractional difference on the series, and obtains the series satisfying the zero-mean ARMA process, then estimates the parameters. Further research shows that the Caputo fractional difference process is a specialized Grunwald-Letnikov (G-L) fractional differential process. Therefore, this paper introduces the Caputo fractional L1 formula into the time series model, and constructs a new fractional difference method to deal with Brent futures price return rate and perform ARFIMA modeling. This method works better in predicting than the traditional ARMA model and the G-L differential ARFIMA model. It can provide more effective assessments in economic markets such as oil price risk measurement and control, helping investors to better avoid market risks and obtain greater returns.