Offsetting particulate matter emissions has become a critical global aim as there are concerted efforts to deal with environmental and energy poverty challenges.This study consists of investigations of computing emiss...Offsetting particulate matter emissions has become a critical global aim as there are concerted efforts to deal with environmental and energy poverty challenges.This study consists of investigations of computing emissions of particulate matter from biomass fuels in various atmospheres and temperatures.The laboratory setup included a fixed bed electric reactor and a particulate matter(PM)measuring machine interfaced with the flue gas from the fixed bed reactor combustion chamber.The experiments were conducted at seven different temperatures(600℃-1200℃)and six incremental oxygen concentrations(21%-100%).Five biomass types were studied;A-cornstalk,B-wood,C-wheat straw,D-Rice husk,E-Peanut shell,each pulverized to a size of approximately 75 microns.The study shows that PM emitted during char combustion is consistently higher than that emitted during the de-volatilization.During de-volatilization,increase in temperature leads to linear decrease in PM emission between atmospheres of 21%O_(2)to 50%O_(2),thereafter,between 70%O_(2)to 100%O_(2);increase in temperature leads to a rise in PM emission.The average PM formation from all the five considered biomass is relatively comparable however,with differing atmospheres and temperatures,the fibrous and low-density biomass forms more PM.During char combustion,the study shows that at oxygen levels of 21%,70%,90%and 100%,increase in temperature leads to increased PM emission.The increase in oxygen concentration and temperature increases the rate of combustion hence diminishing the time of combustion.展开更多
Renewable energy exploitation is among the development strategies set by the government of Rwanda on the roadmap to 2023/2024 universal electricity access and theUnitedNations plans by 2030.Numerous previous studies o...Renewable energy exploitation is among the development strategies set by the government of Rwanda on the roadmap to 2023/2024 universal electricity access and theUnitedNations plans by 2030.Numerous previous studies oncleanenergy technologies inRwandahavemostly focusedonhouseholds’usagebut there are currentlynostudies describing the feasibility of clean energy technologies for financial institutions.The skepticism on renewable energy in Africa was previously reported by some personnel.Having realized that most SACCOs(Savings and Credit Co-Operatives)in Rwanda use diesel technology for backup/emergency electricity supply,taking consideration of abundant solar resources in Rwanda,having seen the viability and feasibility studies from other countries of renewable energy for different institutions(financial included);thiswork uses theHOMEREnergy Software and the electricity load profile of a typical SACCO in Rwanda to analyse the affordability and viability of on-site renewable energy generation for SACCO in Rwanda.The results reveal that a solar PV systemwith storage can be the optimal solution(with levelized cost of electricity(LCOE)of 0.713$/kWh which is cheaper than 0.73$/kWh for diesel technology)for SACCOs located in both off-grid areas and grid-connected areas(with 0.041$/kWh LCOE which is lower than the current electricity tariff in Rwanda).The findings in this work can serve as basic tools/materials for policy drafters in Rwanda on how financial institutions can contribute to climate change mitigation through self-renewable energy exploitation.展开更多
The world’s energy consumption and power generation demand will continue to rise.Furthermore,the bulk of the energy resources needed to satisfy the rising demand is far from the load centers.The aforementioned requir...The world’s energy consumption and power generation demand will continue to rise.Furthermore,the bulk of the energy resources needed to satisfy the rising demand is far from the load centers.The aforementioned requires long-distance transmission systems and one way to accomplish this is to use high voltage direct current(HVDC)transmission systems.The main technical issues for HVDC transmission systems are loss of synchronism,variation of quadrature currents,amplitude,the inability of station 1(rectifier),and station 2(inverter)to either inject,or absorb active,or reactive power in the network in any circumstances(before a fault occurs,during having a fault in network and after a fault cleared),and the variations of power transfer capabilities.Additionally,faults impact power quality such as voltage dips and power line outage time.This paper presents a method of overcoming the aforementioned technical issues using voltage-source converter(VSC)based HVDC transmission systems with SCADA VIEWER software and dynamic grid simulator.The benefits include having a higher capacity transmission system and proposed best method for control of active and reactive power transfer capabilities.Simulation results obtained using MATLAB validated the experimental results from SCADA Viewer software.The results indicate that the station’s rectifier or inverter can either inject or absorb either active power or reactive power in any circumstance.Also,the reverse power flow under different modes of operation can ride through faults.At a 100.0%power transfer rate,the rectifier injected 775.0 W into the network.At a 0.0%power transfer rate,the rectifier injected 164.0 W into the network.At a-100.0%rated power,the rectifier injected 1264.0 W into the network and direction was also changed.展开更多
基金Authors are grateful to Quanzhou Tongjiang Scholar Special Fund for financial support through Grant No.(600005-Z17X0234)Quanzhou Science and Technology Bureau for financial support through Grant No.(2018Z010)+2 种基金Huaqiao University through Grant No.(17BS201)the Fujian ProvincialDepartment of Science and Technology for financial support through Grant(2018J05121)Authors are also grateful for financial support from the Fujian Provincial Department of Science and Technology through Grant Nos.2021I0014 and 2018J05121.
文摘Offsetting particulate matter emissions has become a critical global aim as there are concerted efforts to deal with environmental and energy poverty challenges.This study consists of investigations of computing emissions of particulate matter from biomass fuels in various atmospheres and temperatures.The laboratory setup included a fixed bed electric reactor and a particulate matter(PM)measuring machine interfaced with the flue gas from the fixed bed reactor combustion chamber.The experiments were conducted at seven different temperatures(600℃-1200℃)and six incremental oxygen concentrations(21%-100%).Five biomass types were studied;A-cornstalk,B-wood,C-wheat straw,D-Rice husk,E-Peanut shell,each pulverized to a size of approximately 75 microns.The study shows that PM emitted during char combustion is consistently higher than that emitted during the de-volatilization.During de-volatilization,increase in temperature leads to linear decrease in PM emission between atmospheres of 21%O_(2)to 50%O_(2),thereafter,between 70%O_(2)to 100%O_(2);increase in temperature leads to a rise in PM emission.The average PM formation from all the five considered biomass is relatively comparable however,with differing atmospheres and temperatures,the fibrous and low-density biomass forms more PM.During char combustion,the study shows that at oxygen levels of 21%,70%,90%and 100%,increase in temperature leads to increased PM emission.The increase in oxygen concentration and temperature increases the rate of combustion hence diminishing the time of combustion.
基金Fujian Provincial Department of Science and Technology(Grant Number:2021I0014)Fujian Provincial Department of Housing and Construction(Grant Number:2022-K-67+5 种基金Fujian Provincial Department of Education(Grant Number:JAT201518)Additionally,Authors are grateful to Quanzhou Tongjiang Scholar Special Fund for financial support throughGrant Number:(600005-Z17X0234)Quanzhou Science and Technology Bureau for financial support through Grant Number:(2018Z010)Huaqiao University through Grant Number:(17BS201)the Fujian Provincial Department of Science and Technology for financial support through Grant(2018J05121)Authors are also grateful for financial support from the Fujian Provincial Department of Science and Technology through Grants Numbers:2021I0014 and 2018J05121.
文摘Renewable energy exploitation is among the development strategies set by the government of Rwanda on the roadmap to 2023/2024 universal electricity access and theUnitedNations plans by 2030.Numerous previous studies oncleanenergy technologies inRwandahavemostly focusedonhouseholds’usagebut there are currentlynostudies describing the feasibility of clean energy technologies for financial institutions.The skepticism on renewable energy in Africa was previously reported by some personnel.Having realized that most SACCOs(Savings and Credit Co-Operatives)in Rwanda use diesel technology for backup/emergency electricity supply,taking consideration of abundant solar resources in Rwanda,having seen the viability and feasibility studies from other countries of renewable energy for different institutions(financial included);thiswork uses theHOMEREnergy Software and the electricity load profile of a typical SACCO in Rwanda to analyse the affordability and viability of on-site renewable energy generation for SACCO in Rwanda.The results reveal that a solar PV systemwith storage can be the optimal solution(with levelized cost of electricity(LCOE)of 0.713$/kWh which is cheaper than 0.73$/kWh for diesel technology)for SACCOs located in both off-grid areas and grid-connected areas(with 0.041$/kWh LCOE which is lower than the current electricity tariff in Rwanda).The findings in this work can serve as basic tools/materials for policy drafters in Rwanda on how financial institutions can contribute to climate change mitigation through self-renewable energy exploitation.
基金support through GrantNo.(600005-Z17X0234)Quanzhou Science and Technology Bureau for financial support through Grant No.(2018Z010)+2 种基金Huaqiao University through Grant No.(17BS201)the Fujian Provincial Department of Science and Technology for financial support through Grant(2018J05121)Authors are also grateful for financial support from the Fujian Provincial Department of Science and Technology through Grant Nos.(2021I0014)and(2018J05121).
文摘The world’s energy consumption and power generation demand will continue to rise.Furthermore,the bulk of the energy resources needed to satisfy the rising demand is far from the load centers.The aforementioned requires long-distance transmission systems and one way to accomplish this is to use high voltage direct current(HVDC)transmission systems.The main technical issues for HVDC transmission systems are loss of synchronism,variation of quadrature currents,amplitude,the inability of station 1(rectifier),and station 2(inverter)to either inject,or absorb active,or reactive power in the network in any circumstances(before a fault occurs,during having a fault in network and after a fault cleared),and the variations of power transfer capabilities.Additionally,faults impact power quality such as voltage dips and power line outage time.This paper presents a method of overcoming the aforementioned technical issues using voltage-source converter(VSC)based HVDC transmission systems with SCADA VIEWER software and dynamic grid simulator.The benefits include having a higher capacity transmission system and proposed best method for control of active and reactive power transfer capabilities.Simulation results obtained using MATLAB validated the experimental results from SCADA Viewer software.The results indicate that the station’s rectifier or inverter can either inject or absorb either active power or reactive power in any circumstance.Also,the reverse power flow under different modes of operation can ride through faults.At a 100.0%power transfer rate,the rectifier injected 775.0 W into the network.At a 0.0%power transfer rate,the rectifier injected 164.0 W into the network.At a-100.0%rated power,the rectifier injected 1264.0 W into the network and direction was also changed.
