From the perspective of improvingenergy efficiency andthermal comfortof solar heating system, theactive solar heating systemunder different stragetiesis experimented in Hezuo city, Gansu province, China in the heating season of 2018 to 2019. The conclusions revealthat without increasing energy consumption, smaller the supplyduration and the intermittent duration, higher the heating efficiency. The living room air temperature,average heating rate and cooling rateof the kang surfacetemperature change more slowly. Regardingthe on-off time ratio of 50%, the optimal strategy of the system areto combine 15/15min mode with variable flow mode B to ensure the systemownhigh energy efficiency and well thermal comfort.
In order to further study the effect of internal and external coils on the heating performance of fermenters, this paper studied the advantages and disadvantages of internal and external coil heating fermenters under different TS value materials and different ambient temperature conditions, and passed the total heat transfer coefficient. The heating rate, temperature uniformity and temperature control economy of the fermentation system compare the difference between the inner and outer coils. The results show that the ambient temperature has a great influence on the external coil; as the TS value increases, the inner coil heating rate is higher than the outer coil, but the tank temperature uniformity is lower than the outer coil.
Hydrotreated Vegetable Oil (HVO) and Gas to Liquid fuel (GTL) are two renewable fuels without shortcoming as traditional renewable fuels such as FAME. This project aims to research macroscopic spray characteristics of HVO and GTL during both injection and post-injection periods at high ambient temperature and pressure. The work is conducted by experiments on a constant volume vessel (CVV) system at 1800 bar rail pressure, 10 bar and 40 bar ambient pressure and 600 K ambient temperature. Results indicate that HVO and GTL have similar average cone angle to standard diesel fuel (DF), whilst their spray tip penetration during injection and post-injection periods are both smaller than that of DF. Moreover, the two renewable fuels have faster evaporation at high ambient temperature compared with DF, and thus results in the reduction of spray tip penetration with sample time.
The intermittent of wind power poses a challenge to operation security and stability of power system. The power grid has the potential to guide wind power to be accommodated in a wider geographical region, and its impact is more prominent in real-time dispatch and controlling. Considering the constraints of bus voltage and branch power flow, this paper focus on the of wind power accommodation capability (WPAC) of system and buses, the coupling relationship of the WPAC of different buses is analyzed. In order to assistant real-time dispatch, an evaluation method of WPAC in real-time dispatch considering security constraints of power grid is proposed, which transforms security constraints of power gird into bus output constraints, evaluates WPACs of the system and different buses at a certain period in real time dispatch. The reasonableness and effectiveness of the presented method is validated by case study.
Resilience is used to assess the ability to maintain and recover system performance in an extreme weather, which is one of the most important performance indicators of smart grid. A model for evaluating the hurricane resilience of distribution network considering fault repair is proposed. First, the difference between toughness and reliability is described. Second, to perfect the resilience assessment and analysis method of distribution systems, a component failure probability model under hurricane condition is built, the latin hypercube sampling is used to reduce the failure scenes and a distribution network restoration model considering fault repair is established. Finally, a simulation verifies the validity and accuracy of the proposed approach in this article.
In this paper, study on a volumetric receiver which use for solar energy season storage and heating system. This type of volumetric receiver has a high heat capacity, so that volumetric receiver can be ensured under severe weather conditions. In order to provide a reference for design and modification of volumetric receiver, the heat transfer characteristics of the volumetric heat absorber are studied. The influence of extinction coefficient and wind speed on the heat transfer characteristics of the volumetric receiver is analyzed by single factor analysis.
In this paper, we analyze the implications of fully or nearly fully decarbonizing the European electric system by 2050. Future power mixes trajectories are computed with a 5 year time step at country level using eTIMES-EU, a bottom-up optimization model for the EU power sector. By comparing a near carbon neutral case (TGT90) with a fully decarbonized system (NEUTR), we discuss the additional costs, capacities and trading implications. Increasing the ambition from 90% mitigation goal to strict neutrality requires 32.6% more investments in 2050, 394 GW additional solar capacity in 2050 and more reliance on trade between countries.
This paper conducts and compares the computational modelling of two cooling and power systems, integrating organic Rankine cycle (ORC) with adsorption cycles. The kinetic sorption models of MnCl2-EG and MnCl2-EG-Ni@C are established and validated via the data in previous study. The result shows a higher thermal efficiency of utilizing adsorption units as the top user of the heat source. Moreover, it is demonstrated that using the novel sorbents with Ni@C could improve the cooling production and the thermal efficiency of the cogeneration system.
The renewable energy industry is widely utilizing biomass as one of the extraction sources. Pyrolysis is among the most commonly used technique to process biomass into desired fuels. Biomass mainly consist of cellulose, hemicellulose and lignin that will decompose differently during pyrolysis yielding valuable bio-oil, biogas and bio-char. Traditional experimental work to study biomass pyrolysis could be complex and time consuming. This study has utilized SuperPro Designer (SPD) as a modelling tool to investigate the pyrolytic behavior of biomass constituents and product distributions. The model was built based on kinetic studies of lignocellulosic reaction pathways. The obtained results were verified with experimental as well as literature data. The flexibility and accuracy of SPD model were also tested with different biomass species. The model was validated and can be used as a predictive and optimization tool for the study of biomass pyrolysis.
Pre-treatment and storage of agriculture residue are crucial for its supply chain. To investigate the effect of pre-treatment methods (i.e. torrefaction and compaction), the number of storage depot, and power generation technology on supply chain model, this work compared 7 scenarios in order to optimize supply chain model for power generation in China using corn stalk as feedstock. Furthermore, the influential roles of supply chain parameters on power generation profitability will be investigated through sensitivity analysis. It was found that combined heat and power based power generation shows significant profitability compared with electricity generation. The results approved that supply chain model reaches the highest profitability with compaction as pre-treatment method and 9 storage depots. According to sensitivity analysis results, the capital investment cost of power plant is the most influential parameter for supply chain profitability, the followed by is the purchasing price of corn stock residues.