This paper describes the thermal performance of an adsorption refrigerator system utilizing activated carbon-ammonia pair. The experiment was done by using thermal energy supplied by electric tape heater to the adsorber at selected temperature of 110°C with varied desorption time from 1 to 4 hours. Records of energy consumption, temperatures for adsorber, condenser, evaporator cold chamber and adsorber pressure were taken. The prototype tested attained evaporator cold chamber temperatures varying from 4.8°C to -0.6°C for desorption times of 1 to 4 hours. These temperatures are relevant to the vaccine storage requirement of 2C to 8C. Therefore, this adsorption refrigeration technology, which can be easily manufactured in least industrialised countries is a promising solution for off grid application.
China is a vast country with great regional variations in economy level, resource endowments, industrial structure, demographics, and CO2 emissions level. Previous studies on regional CO2 emissions were usually confined to production- or consumption-based perspectives and neglected the emissions under income-based perspective as they also can be enabled by the use of primary inputs. To fill this gap, we investigate the variations of provincial CO2 emissions under these three perspectives in China during 2007–2012 and intend to identify out which type of final demand and primary input contributes most to the variations of provincial CO2 emissions. Results show that variations of domestic outflow and gross fixed capital formation contributed most to the emissions growth for most provinces under consumption-based perspective, while variations of domestic inflow and compensation of employees did so under income-based perspective. This work can help guide the development of just and effective mitigation policies for various provinces in China.
Nowadays, the fundamental idea of district heating (DH) is to utilize local heat resources to satisfy local heat demands, otherwise those resources would be wasted. However, the mismatch between the achievable resources and fluctuating demand is challenging. This study analyzed the possibilities to solve this problem by introducing a short-term thermal storage and a seasonal thermal storage. A water tank (WT) and a borehole thermal storage (BTS) were chosen as the thermal storages. The DH system of a Norwegian university campus was selected as the case study. A high order system model was built in Modelica language. The results showed that the mismatch might be solved. The BTS brought about 3 GWh annual heat saving, and the WT brought about 110 kW average peak load shaving. However, around 0.8 GWh/year electricity was used by heat pump to recover the stored heat in the ground.
This article aims to model the transmission architecture of a planetary power split Hybrid Electric Vehicle (HEV) to improve fuel efficiency as well as to reduce emission, conforming sustainable design. The model is developed using model based equations, retrieved from literature and Design of Experiment with response surface solution mode. Development of power management strategy for the above, utilizing associated mathematical modeling of the proposed gearset topology guided transmission architecture is disseminated in this work. Design solution for suitable gearset topology is derived by utilizing response surface method and genetic algorithm. The result shows that connection between planetary gear stages, amongst considered variables, holds highest significance and also helps to infer that most suitable configuration is to couple the engine with the second planet carrier for a two-stage power split device. The modelling-based result depicts successful implementation of two stage planetary gear train as power split device with fossil fuel consumption reduction of 49.16%, maximizing electric power utilization for greener transportation.
Driven by climate change concerns, our energy system has been under steady change. Renewable energy sources are increasingly used to decarbonize our energy system, making it also more decentralized. At the same time, information and communications technologies (ICT) are enabling smart services for consumers, offering financial benefits through demand side management (DSM) programs. This study investigates various DSM solutions for a detached house in Northern Finnish conditions in 2050. A thermal model is used to model the thermal behavior of the building and test out DSM programs in direct electric space heating and underfloor heating alternatives. The 2050 scenarios are created from climate change projections, existing data on electricity generation and from projections on the future energy system and cost of electricity. The results indicate that load shifting with photovoltaic (PV) generation is a potential way of reducing costs and CO2 emissions both today and in 2050, but it lacks economic feasibility due to long payback times of the investments. Cost optimized direct electric space heating and underfloor heating are both able to provide economic and environmental benefits when compared to manually controlled heating. The scenarios presented in the paper suggest that 95-96% emission reduction can be achieved; however, the electricity cost of households is expected to increase by 174-253%. At the same time electricity consumption from the grid is expected to reduce by 3- 10% in all the scenarios.
Large scale utilization of solar energy has become an inevitable trend of an energy-efficient and environment-friendly society. A two-stage robust allocation model of solar energy equipments in district integrated energy systems is proposed in this paper with the uncertainty of solar irradiance and operating constraints of energy networks. To improve the solvability, the above non-convex non-linear model is converted to a 0-1 mixed integer second-order cone problem. The validity of the model is verified by typical cases.
Thermal management of large-format Li-ion cells is crucial due to their spatial- and temperature-dependent electrochemical reaction kinetics and heat generation. However, existing battery modeling mostly employs a pseudo-2D model which is not able to capture the local current density and temperature across the entire cell geometry. Therefore, in this paper, we propose a simplified 3D electrochemical/thermal model to investigate the temperature and voltage responses of a Li-ion pouch cell. Concurrently, a lock-in thermography experiment is conducted. The model can achieve good accuracy in predicting the surface temperature and cell voltage of the battery during cycling. A scaling analysis is subsequently carried out to determine the dimensionless numbers that affect the battery performance. The proposed approach helps to facilitate a fundamental understanding of the dominant mechanisms related to voltage polarization, heat generation and temperature non-uniformity.
The prospect of using biomass alone is broad, but there are a number of problems that make it difficult to achieve real profitability. In this paper, the thermal effects and reaction kinetics of cellulose and low-rank coal mixing at different mixing rates (25 wt%, 50 wt.% and 75 wt.%) and different heating rates (10 oC•min-1 , 20 oC•min-1 , 40 oC•min-1 ) were studied via thermogravimetric analyzer(TGA). The addition of low-rank coal can promote the formation of volatile substances in the copyrolysis process, and the degree of synergy is closely related to the heating rate and blending ratio. The kinetic results show that the average activation is 244.44 kJ•mol1 and 164.41 kJ•mol-1 when the low-rank coal blending ratio is 25% and 50%.
Mixed CH4-THF hydrate formation has been investigated at ambient temperature (298 K) with focus on advancing the commercial feasibility of solidified natural gas (SNG) technology for natural gas storage. In addition to freshwater, direct use of seawater has also been studied for hydrate formation. There is quite a gulf between the two systems at the chosen experimental temperature of 298 K with final gas uptake for the freshwater system being more than double that of its seawater counterpart while the kinetics of hydrate formation also shows a marked difference, in favor of freshwater. To improve the kinetics of hydrate formation from seawater, possible use of two kinetic promoters, hydrophilic amino acid L-Arginine and hydrophobic amino acid L-Tryptophan has been proposed. Both kinetic promoters used enhance the kinetics of hydrate formation from seawater and while the final gas uptake is roughly equivalent for the systems without any promoter and with hydrophobic L-Tryptophan, presence of hydrophilic amino acid L-Arginine increases the final gas uptake obtained for seawater as well.
Transport sector around the world is in a transition era by experiencing a disruption of electric vehicle (EV) technology. This transition brings both challenges and opportunities to energy system and energy pattern in transport sector, such as increasing of electricity demand and reduction of greenhouse gas (GHG) emissions. This study aims to analyse the potential future scenarios of the penetration of EV in Thailand’s road transport sector. In addition, the impacts of such technology to energy demand and supply and potential of GHG emission reduction in transport sector will also be assessed.
Policy commitment of the government plays a crucial role for EVs market in Thailand. Therefore, the future scenarios can be explored by two cases: Current Policy Scenario (CPS) represents the current actions of government support on EVs, whereas Proactive Policy Scenario (PPS) represents full package of government supports on both supply and demand sides. High penetration rate of EVs will impacts on Thailand energy system, especially road transport sector. This include total energy demand pattern, load profile of electricity demand and GHG emission. The results present that total number of EVs in PPS scenario will consume electricity more than that of CPS scenario around 1,650 ktoe (19,363 GWh), however, they can reduce 474 ktoe of total energy consumption and 10 MtCO2eq by 2040.