Ebook: Proceedings of the 2nd International Conference on Green Energy, Environment and Sustainable Development (GEESD2021)

The 2021 2nd International Conference on Green Energy, Environment and Sustainable Development (GEESD2021) was held successfully on June 26, 2021. Due to the COVID-19 pandemic around the world, and with the strict travelling rules in China, it was still difficult for our attendees abroad to travel internationally. Therefore, GEESD2021 was held both in physical form (Shanghai, China) and online (Zoom).

About 80 attendees have participated in the conference. The one-day conference was divided into three parts: two keynote speeches in the morning, each 45 minutes, and 16 oral presentations, each 15 minutes, in the afternoon. Besides, 44 e-posters were presented on the conference website. The session chairs and keynote speakers have worked together to selected the best oral presentation and poster presentation.

This year, GEESD2021 attracted more than 250 submissions, and 88 of them have been accepted to be included in this collection of papers. The process of evaluation and peer-review lasted for about 6 months, with more than 100 TPC members and reviewers involved in. We would like to express our sincere gratitude to all experts for their professional and detailed review comments, which have contributed to the high standard of this collection.

This proceedings consists of three main parts: (1) Sustainable Energy; (2) Ecology; (3) Environmental Pollution and Protection, with the most up-to-date findings and technologies being discussed. We believe participants of GEESD2021 have gained knowledge as well as met new friends in the same field. And we hope this proceedings will benefit the readers in the same way.

Changbo Cheng

Hubei Zhongke Institute of Geology and Environment Technology

Wetlands in northern China are complex ecosystems composed of grasslands, lakes, rivers and swamps, which have immense ecological values. When a highway system passes through a wetland, it has adverse effects on its ecosystem. However, in many cases, it is difficult to avoid a highway system pass through a wetland. Taking the Erka wetland in northern China as an example, nine survey lines, perpendicular to the highway, were set up. According to the distance from the highway, the plant multi-element information was collected. After the analysis of plant growth habits, spatial characteristics and profile features, the following four conclusions were drawn: (1) the highway system divided the plants habitat and made the vegetation communities on both sides develop anisotropically; (2) the highway system interfered with the interspecific competition of the nearby plant populations, making it easier for the plant communities with fast propagation speed, drought resistance and anti-interference to establish advantages; (3) the plant growth within 80 m of the highway was inhibited and (4) the wetland plant community succeeded to grassland plant community. In order to reduce the adverse impact of highway system on wetland ecosystems, it is suggested that in the follow-up highway upgrading project, either diversion of highway or construction of bridge or culvert excavation should be considered.

The phenomenon of three phase voltage imbalance frequently occurs in large-scale new energy grid connected areas in China; in severe cases, a large number of wind turbines will be disconnected from the grid. To solve the problem of the voltage imbalance at the point of common coupling (PCC), analyze the influence of generator parameters change on negative sequence voltage under the background of unbalanced power grid, a modeling method of base-frequency negative sequence impedance of doubly fed induction generator (DFIG) which including phase locked loop (PLL), rotor side converter (RSC) and grid side converter (GSC) is proposed. By establishing the negative sequence equivalent circuit of grid-connected system of DFIG, the relationship between the negative sequence voltage of PCC and the negative sequence impedance of DFIG is listed, and analyzing the sensitivity of control parameters link to base-frequency impedance, the parameter that has great influence on base-frequency negative sequence impedance of PCC is found out. Finally, the accuracy of impedance modeling and sensitivity analysis is verified by simulation studies.

The multi-directional variation of results among environmental regulation, resource utilization, and Research and Development (R&D) investments continue to gain more popularity but few studies have examined the nexus among these variables in an open economy. To analyze the individual and combined effects of environmental regulation and resource utilization on industrial R&D investments, a panel data of 30 provinces in China from 2008 to 2018 was used. We also examined the mechanism underlying the magnitude of pollution inducement on R&D investment. The results show that environmental regulation significantly and positively promotes R&D investment while resource utilization has an inverse effect. Environmental regulation does not interfere with efficiency and neither does the quest for efficiency in resource utilization weaken the impact of environmental regulation on R&D investment. Only a few provinces are within the rising stages of the inverted n-shaped curve indicating environmental regulation level is still low. Even though there are tighter laws, government needs to continue to put in more stringent environmental policies towards achieving sustainable development.

In the flexible AC/DC distribution system supplying passive network, when the modular multi-level converter (MMC) inverter AC line fault occurs, the MMC short-circuit current amplitude is greatly affected by the control strategy, which may affect the operation performance of three-stage current protection. In view of this, a flexible AC/DC distribution network system supplying power to the passive network is built on the RTDS platform, and then the AC fault traverse strategy is designed in the MMC controller. Based on the thinking of coordinated control and protection of the fault through the strategy into two cases with no input to higher current protections performance simulation contrast, the simulation results show that asymmetric fault occurred when MMC inverter AC line, under the effect of communication failure through the strategy, the current main protection I, II period of refusing action, only by this line nearly backup protection current section III delay removal of fault. The three-stage current protection based on the fault current characteristics of pure AC system has poor action performance and is no longer suitable for the AC line of MMC inverter station.

High permeability zones in the water-drive gas reservoir tend to act as dominant channels for formation water to invade into gas reservoir from the aquifer. The presence of high permeability zones results in uneven water flow front in reservoir and early water breakthrough in gas well, which seriously affects the gas field development. In this paper, conventional logging and production logging data are used to identify and characterize high permeability zones, so as to guide the optimization of development plan of Kela 2 gas field. A method to determine the lower limit of high permeability zones by using cumulative frequency curve of permeability distribution is proposed, and high permeability zones of 21 wells are identified. These high permeability zones account for 10–15% of the effective reservoir thickness in single wells, and they are mainly distributed in the middle of the Bashijiqike (K1bs) Formation (i.e., K1bs12, K1bs21 and K1bs22). The analysis of production logging data shows that the effective gas producing intervals only account for 29.2% of the total number of test intervals, most of which are related to high permeability zones. Further study shows that the high gas flow from the high permeability zones dominates the wellbore production profile, and the gas in low permeability zones flows vertically to the high permeability zones and horizontally to wellbore through these zones. Through the analysis of production profiles over the years and computer modelling, it is confirmed that water channelling occurred in some gas wells at the depth where the high permeability zones are located, which leads to a significant decline in production of these wells. Based on the study of distribution and behaviour characteristics of the high permeability zones, two suggestions on controlling inhomogeneous water invasion are put forward to realize the sustainable and stable production of the gas field.

Research on the regional fracture’s development is important for reservoir fracturing. This paper takes the Carboniferous volcanic reservoir in the northwestern margin of Junggar Basin as the research object. Based on understanding the regional tectonic faults and geological characteristics, the parameter characteristics of natural fractures are analyzed using imaging logging data, and natural fractures distribution characteristics are compared with regional faults and in-situ stresses, as well as the pattern of natural fractures formation is revealed. The results indicated that: (1) The Carboniferous in the northwestern margin of Junggar Basin area mainly develops 3 NE-trending reverse faults. The reservoir type is pore-fracture dual media type, with an average porosity of 7.64% and an average permeability of 1.16mD, which belongs to the medium-porosity and ultra-low permeability reservoir; (2) Reservoir fractures are generally well developed. High-conductivity fractures and high-resistance fractures coexist, but high-conductivity fractures are the main ones. The fracture width is between 0.053 and 0.23 mm, and the fracture density is between 0.5 and 1.68 strips/m. The length is between 0.54-1.88m, the fracture porosity is between 3.4×10^-5-41×10^-5, and the dominant fracture trend is mainly NE50°-NE80°; (3) The direction of the maximum horizontal in-situ stress of the reservoir is mainly NE30°-NE60°, in the direction of NEE, it differs from fracture strike by 10°-50°, and roughly the same as the strike of the three reverse faults.

Thermal design of IGBT is the key technology on wind power converter design. This paper introduced a theoretical calculation method of IGBT power loss which is applicable in wind power converter engineering applications. Meantime, the corresponding mathematic model was established. Considering the divergence of application environments as well as the characteristics of water-cooling heat dissipation, simulation models of two different inlet and outlet position radiators were built in Ansys software. And then the cooling capacity of these two types of radiators was analyzed though simulation. According to the simulation results, the ipsilateral inlet and outlet channel mode radiator was selected. After the sample production of the water cooling plate is completed, the experimental platform is built and the sample was verified. Finally, the experiment results indicated the rationality and practicability of the thermal design and simulation, which provided critical references of IGBT water cooling system design. In this paper, the performance of water cooling radiators is studied, which also provides a reference for the design of other high power electronic products.

For the increasingly prominent problems of wind turbine maintenance, using edge cloud collaboration technology to construct wind farm equipment operation and maintenance framework is proposed, digital twin is used for fault prediction and diagnosis. Framework consists of data source layer, edge computing node layer, public or private cloud. Data source layer solves acquisition and transmission of wind turbine operation and maintenance data, edge computing node layer is responsible for on-site data cloud computing, storage and data transmission to cloud computing layer, receiving cloud computing results, device driving and control. The cloud computing layer completes the big data calculation and storage from wind farm, except that, based on real-time data records, continuous simulation and optimization, correct failure prediction mode, expert database and its prediction software, and edge node interaction and shared intelligence. The research explains that wind turbine uses digital twin to do fault prediction and diagnosis model, condition assessment, feature analysis and diagnosis, life prediction, combining with the probabilistic digital twin model to make the maintenance plan and decision-making method.

In the filling and transportation processes of liquefied natural gas (LNG), the safety of LNG storage tanks is compromised because of rollover phenomenon. As such, the rollover factors of LNG in a storage tank should be identified to prevent or weaken the rollover intensity of LNG. In this study, the rollover behavior of LNG in a storage tank is numerically simulated. The density of the two layers in a LNG storage tank is related to temperature in our numerical model. It is found that the greater the significant initial density difference (range of 1-12 kg·m^-3) is, the more obvious the LNG rollover will be. A density difference of 7.5 kg·m^-3 is found as the critical density difference in the present work. When the initial density difference exceeds the critical density difference, the LNG rollover coefficients increase dramatically. Moreover, an LNG rollover model with two daughter models is proposed, which are divided by the critical initial density difference, i.e., a cubic relationship between rollover coefficients and the initial density difference when the density difference is less than 7.5 kg·m^-3 and secondly, a linear relationship between the rollover coefficient and the double exponential functions when the density difference is larger than 7.5 kg·m^-3.

In order to solve the contradiction between heating supply and demand in solar energy system in a residential area of Ordos, a solar heating system has been designed, tested, and analyzed for over a month. The main purpose of this paper is to evaluate the primary energy consumption, the carbon dioxide emissions, the initial investment, and the operation costs of the floor radiant and forced convection radiator configuration on the overall performance of the system, and analyzes its potential economic benefits. A parametric analysis has been performed in order to investigate the performance of a solar heating system integrated with dynamic automatic control system upon varying the different terminal device. Results from the present study indicate that the thermal comfort of the proposed system with forced convection radiator configuration is better than the conventional system, And the above four indices reductions from energy efficiency improvements and solar energy supply exceed over 50%.

Vigorously promoting the development of photovoltaic (PV) resources is a positive measure taken by humanity in response to the changes in global climate and environment. At the same time, combining photovoltaic power generation systems with traditional power generation systems, using the advantages of different power generation systems to achieve real-time scheduling optimization has become an urgent problem to be solved in engineering applications. This paper attempts to study the climate and environmental benefits of the development of photovoltaic resource in Africa by taking Angola as an example based on actual project data. According to the characteristics, load requirements, seasonal characteristics and actual engineering background of Tombwa in Angola, a baseline Scenario and four comparative Scenarios were established, and the operating costs of the five Scenarios in local rainy season and dry season were obtained respectively. The cost of electricity for the five Scenarios calculated subsequently. Through real-time scheduling and optimization of the software, the emission characteristics of CO₂, NO_x and CO under five Scenarios are obtained, and the climate benefits and environmental benefits of the five scenarios are further analyzed and compared. The results show that the development of photovoltaic resources in Angola has good climate and environmental benefits. In addition, the combine application of diesel, PV and battery power system will be the most effective of the five Scenarios to reduce the CO₂ emissions with the lowest levelized cost of electricity (LCOE) of 0.38 yuan/kwh, as a cost-effective solution in remote areas of Angola, Africa.

As the coupling of photovoltaic (PV) and agriculture, PV agriculture can effectively promote the development of the PV industry and modern agriculture. PV agriculture has attracted numerous countries, prompting the emergence of a growing number of PV farms. As the largest polysilicon producer with large agricultural production area and abundant solar energy resources, China is selected as a case study. This paper identifies indicate that the weakness-threat (WT) strategy should be adopted to promote the development of PV agriculture in China by establishing a unified support policy, encouraging the participation of market capital, and promoting the development of related technology. Similarly, the Chinese scenario might provide a useful reference for other developing countries.

As world energy consumption intensifies, the oil and gas exploitation technology in the polar region are drawing more and more attention. However, due to the harsh environment, the oil and gas exploitation operation in the polar region are faced with enormous challenges, such as low temperature and sea ice collision, etc. This paper mainly focuses on the structural strength and integrity study of the arctic drilling riser suffering from the floe collision loading. First, the discrete element software IceDEM is employed to develop a local drilling riser - sea ice interaction model subjected to the floe collision loading in the splash zone, and the corresponding dynamic collision response between the drilling riser and the floe ice could be calculated and acquired. Then, a global drilling riser model is built within the framework of general finite element analysis software ABAQUS to investigate the dynamic behavior of the arctic drilling riser in the polar environment, and the dynamic collision loading derived from IceDEM simulation is also introduced in this global model. Finally, the dynamic responses of the arctic drilling riser based on the finite element simulation are investigated to research the riser’s security and integrity, which can provide reference for the design and application of the drilling riser in the polar region.

Aiming at the problems of low utilization rate of solar energy and poor anti-interference ability of tracking structure solar energy control system in fixed structure solar energy device, this paper designs a dual axis high-precision solar tracking system based on four quadrant rule. The system adopts two ways: automatic tracking and manual correction. The system uses four photoresistors as detection elements, uses the four quadrant principle to judge the tracking offset angle, and drives two-dimensional two axis stepper motor through STC89C52 processor to achieve the purpose of vertical angle, so as to ensure that the solar panel is always in the state of maximum light receiving surface; When the system is disturbed, it can be judged according to the change of the photosensitive resistance in the energy monitoring system, and the artificial correction can be realized by modulating the size of the divider resistance, which can basically achieve 360° Automatic rotation tracking. In addition, the energy monitoring system based on LabView is designed. Through the real system analysis, it can be concluded that the photoelectric energy conversion rate of the fixed solar device is increased by 32.4%.

This paper is dedicated to solving the distributed optimization of generation dispatch of multi-area AC systems interconnected by DC lines, which aims at minimizing the total generation cost while satisfying the power supply demand balance and generation capacity constraints. A novel nodal loss formula which derived from the branch active power flow equation is proposed based on phase angle and impedance to improve the system economy. A distributed algorithm based on consensus is built to solve the generation dispatch problem. It has a great effect on improving convergence effect and rate of the system. The control strategy is used on the structure of multi-area interconnection, which improves the reliability of power supply and guarantee the power quality. The study was conducted using three area AC systems interconnected by DC lines. The simulation results show that the proposed generation dispatch method is reliable in convergence. It provides an effective tool for distributed optimization of generation dispatch of multi-area AC systems interconnected by DC lines.

Marine diesel engine is developing towards the direction of precision, automation and systematization, and it has the characteristics of complex structure and many parts. If it breaks down, it will affect the operation safety of the whole ship. If it is serious, accidents may occur, which may cause maritime accidents. Therefore, how to prevent the occurrence of marine diesel engine failure and analyze the cause of failure after the accident has been paid more and more attention by scholars at home and abroad. In the simulation study of the working process of diesel engine, for different types of diesel engines, the laws of combustion process are different, even for the same diesel engine in different working conditions, the combustion laws are also different, which will cause great difficulties to study the combustion process. Using computer simulation technology, the physical calculation model of diesel engine system is established by simulating the typical combustion faults of marine diesel engine. AVL-FIRE software is used to simulate different faults of diesel engine combustion process, and the changes of various performance parameters of diesel engine under corresponding faults are obtained, so as to grasp its working state macroscopically, and provide relevant basis for the design, optimization and operation management of diesel engine system.

Since the 1980s, the direct current (DC) transmission technology has developed rapidly in China. However, with the large-scale application of DC transmission technology, new problems are brought to the power system. Commutation failure of the DC system will cause overvoltage in the alternating current (AC) power network, which will cause great harm to the weak AC system with wind power access. Therefore, it is urgent to carry out research on overvoltage suppression at the sending end of AC system. This paper reveals the formation mechanism of transient overvoltage and confirms that the control parameters of DC system influence the voltage at the sending end directly. And the appropriate control parameters were selected to suppress the overvoltage by the parameter optimization based on genetic algorithm (GA).

SAPO-20 molecular sieve with the SOD framework was successfully synthesized using SAPO-34 as the precursor and isopropylamine (IPA) as the template by phase-transformation route. The influence of post-treatment time (in IPA, H₂O, and SAPO-34 system) and NaOH concentration (in IPA, NaOH, H₂O, and SAPO-34 system) on the products was investigated. The results showed that sheet debris SAPO-34 building the hollow-inside cubic morphologies which was padding with irregular SAPO-34. It was received for the as-synthesized spherical aggregation SAPO-20 with hexagonal shape when the ratio of n(OH^-)/n (H₂O) is 0.12 and the ratio of n(IPA)/n (H₂O) is 0.07 in the synthesis gel. This method not only develops a new route for the synthesis of SAPO-20 molecular sieve, but also provides a way of using waste SAPO-34 catalyst, which can be used as a new exploration model for energy saving, consumption reduction and comprehensive utilization in SAPO-34 catalyst process.

Nonylphenol (NP) is a typical environmental endocrine disruptor with low concentration and high toxicity, μg/L level of NP is enough to interfere with the sex differentiation of many aquatic organisms and affect the population dynamic balance. The mechanism and pathway of NP degradation in aqueous solution by strong ionization dielectric barrier discharge were studied. The results showed that the degradation rate of NP can reach 95.2% in 60 min when the flow rate of O₃ is 5 L/min and the input voltage is 3.8 kV. Based on the electron spin resonance (ESR) results and the detection of O₃, a large amount of hydroxyl radical (·OH) and O₃ were verified. In addition, the ability of DBD method to degrade NP was also tested. The intermediate products were analyzed by liquid chromatography-mass spectrometry (LC-MS), and the degradation pathway was speculated.

This paper discusses the energy matching problem between wave energy input and generator power output, in the power performance assessment for the energy storage type of wave energy converter. Under the small wave condition, the power performance of the energy storage type of wave energy converter is researched. The site test data processing method is analyzed, and the calculation method of the average conversion efficiency and the annual energy production are optimized. The results show that the optimized power performance analysis method can more accurately assess the power performance matrix of the wave energy converter, and improve the calculation accuracy of the average conversion efficiency and the annual energy production of the wave energy converter. The research results provide an effective method for more scientific and accurate evaluation of power performance indexes of the energy storage type of wave energy converters.

This paper presents an electromagnetic vibration energy harvester utilizing 3D MEMS coils and multi-mode structure to improve the output power and broaden the frequency band. We fabricated and assembled the prototype, with a pair of 3D coils fabricated by lithography, silicon etching, silicon direct bonding and copper electroplating, et al., which are compatible with CMOS processes. The numerical simulation was conducted to analysis the vibration modes of the spring-mass system, which revealed the multi-mode mechanism of serpentine springs. We also tested the output power-frequency curves for different load and excitation acceleration to investigate the optimal load resistance and the influence of excitation. The test results showed that the proposed prototype can generate 1.2μW power under 992Hz for 1g acceleration with a half-power bandwidth of 65Hz, which are higher than some recent published data, proving the superiority of proposed structure.

This paper characterizes the pressure drop of incompressible airflow when passing by a metal mesh screen which acts as a protection from sucking foreign solid matters before the gas turbine compressor. The wire diameter is 1.2mm and the mesh number is 3. Two experiments are conducted in different time period of a day to guarantee the experimental repeatability. The experimental data are used in regression analysis to obtain a quadratic correlation between the pressure drop across the screen and the fluid velocity. Numerical simulations are utilized to investigate detailed velocity and pressure fields around the wires and the Standard k-ε turbulence model is used. The results show that the fluid suffers from around 140Pa and 250Pa total pressure drop at the velocity of 20m/s and 30m/s respectively. The pressure closely upstream of the wires is as high as 4 times of the inlet flow level, while wide negative pressure regions are observed downstream of the wires resulting from fluid stagnation, reverse flow and recirculation. The empirical correlation obtained in the paper has a high confidence level and can be used in calculating the overall pressure drop of the gas turbine air intake system.

With the proposal of the concept of carbon neutrality in China, the market will continue to pay more attention to sustainable energy and energy conversion. The management of the power system is a very important part in this field due to the discontinuity of wind energy and solar energy, which is also called power dispatching. It is particularly important in the process of power system conversion and management, so it is very helpful to understand the development and bottleneck of power system to understand the main research content of power dispatching through literature. Based on machine learning and text mining, this paper analyses the related research of power dispatching. The results show that the related papers of power dispatching mainly include safe operation, power dispatching strategy, power dispatching automation, power dispatching technology analysis and so on. This paper also shows the results by a clear visualization method.