Abstract

In order to solve the problem of renewable energy consumption, this paper focuses on the study of dynamic adjustment methods of maximum transmission power capacity for the key transmission sections. Firstly, based on the current power grid company’s simulation ideas for solving cross-sectional quotas, a step-size search simulation sample generation method is proposed. Then based on the BP neural network optimized by the LM algorithm, a model that can quickly determine the transmission section quota is established. Finally, the effectiveness of the model is verified through the operating data of the Western China Power Grid. The results show that the model can fit the non-linear relationship between the generator output combination and the section transmission quota well, and has great practical value.

Abstract

The multi-energy ship, which is composed of renewable energy and hybrid ship, has the advantages of energy saving and emission reduction under the background of increasing global oil resources’ tense. At the same time, structure improvement is an effective way to improve the effectiveness of energy management strategy. To the above end, based on the wind and solar power data generated by HOMER, we establish and apply the extreme scenarios of wind and solar output power. Secondly, we propose a main and auxiliary generator set structure in which the main generator bears the baseload and the auxiliary generator bears the fluctuating load. Based on the structure and dynamic programming algorithm, we establish an energy management model of multi-energy ship with the battery and generator power as the control variables and the minimum operating cost as the optimization goal. The simulation results show that the application of dynamic programming algorithm, wind-solar energy, and main and auxiliary generator set structure combined with dynamic programming algorithm can respectively reduce the ship energy consumption by 0.54%, 5.07%, and 0.80%. The results show that supposed method can effectively reduce the energy consumption of the ship.

Abstract

The energy consumption of carbon-based fuels production can be decrease through direct electrolytic (bi)carbonate conversion due to its lack of the energyextensive process (CO2 release, CO2 compression and production separation), compared to electrolytic gaseous CO2 conversion. In this study, life-cycle and economic assessments are performed to evaluate the energy conversion characteristics, environment impacts and economic benefits of CO production via the two pathways. The results show that the net energy input, greenhouse gas emissions and net present value of electrolytic (bi)carbonate conversion are 10.4905 GJ/(t CO2 gas), -0.6287 t CO2-eq/(t CO2 gas) and $ 42,264,560, respectively, whereas in CO production through electrolytic gaseous CO2 conversion, the corresponding values are 32.5314 GJ/(t CO2 gas), -0.2949 t CO2-eq/(t CO2 gas) and $52,917,640, respectively. Additionally, according to the sensitivity analysis, the cell voltage and Faradaic efficiency have the maximum effects on the net energy input and net present value. The greenhouse gas emissions are affected mainly by the efficiency capture. This study demonstrates the prospect and provides a theoretical direction to promote the technical and economic benefits of carbon-based fuels production via electrolytic conversion from (bi)carbonate

Abstract

Modification of the immediate flow field by means of an upstream circular body has been effective in the energy harvesting improvement of circular oscillators. In this empirical study, the influence of square wake on the harnessed power and efficiency of circular oscillators is investigated. The subject has not been addressed by other researchers. The results show that the square wake has Improving effects on the mechanical power of circular oscillators but deteriorates the hydroelastic efficiency. The overall energy harvesting performance of circular oscillators under nearby square wake is slightly higher than that in single configuration but is almost half of that under circular wake.

Abstract

In this study, a two-phase liquid-immersion cooling system was developed for ICT (Information communication technology equipment) cooling. The PUE energy efficiency of the two-phase cooling system was evaluated under various IT loads, and the annual PUE was calculated dependent on the meteorological parameters in Shanghai. Then, exergy analysis of the two-phase cooling system was taken based on the second law of thermodynamics. The observations and conclusions in this study can be valuable references for the study of cooling systems in data centers.

Abstract

 Heat demand prediction is a notable research topic in intelligent energy networks (IENs), due to the rapid growth of heat demand in cities. Given that hourly heat demand data can be considered as a time series data recording and well analyzed by time series seasonal decomposition algorithms, we develop a variant of the recurrent neural network (RNN), namely time frequency-domain memory (TFDM). The TFDM combines fast Fourier transform (FFT) and long short-term memory (LSTM) model to preserve memory of the series in both time and frequency domains, and cascades a residual block to introduce the impact factors (e.g., weathers). In the experiments, we compare the proposed TFDM with various referred methods on a heat demand dataset. The experimental results show that the proposed TFDM has significant performance improvement in the heat demand prediction.

Abstract

The effect of alkali metal sodium on the NOx formation characteristic of zhundong coal under different temperatures, combustion atmospheres and loading amounts were studied on a fixed bed experimental system. The results show that alkali metal sodium could suppress the formation of NOx during coal combustion. The peak value of volatile nitrogen decreases with the increase in the adding amount of NaCl and increase with the temperature. When the combustion temperature is 1773 K, the alkali metal sodium addition of 1% has the most significant inhibitory effect on the NOx formation. The NOx conversion ratio can be reduced by 45.8%.

Abstract

The cyclone-fired boilers are very suitable for burning high-alkali content coal due to high slag capture rate and low flue gas dust content. However, NOx generation in cyclone-fired boilers is higher than that in other boiler types. In this work, the NOx generation characteristic of cyclone combustion was studied in a 100 kW cyclone combustion test bench. The results show that a strong reducing atmosphere is formed in cyclone barrel, and NOx generation is greatly inhibited in cyclone air-staging combustion. In cyclone barrel, NOx generation is high in the near-wall zone and low in the central zone. The central zone is the core region of NOx reduction. After the over fire air (OFA) injects into the burnout furnace, an obvious increase in NOx concentration is observed, which may be due to oxidation of char-N residue in char in burnout furnace.

Abstract

Cogeneration system in the cane sugar industry consists of boiler, steam turbine, and evaporation process. Bagasse is used as fuel in boiler. Bagasse has a high moisture content, which leads to the inefficiency of energy conversion. The integration of steam dryer in cogeneration system to reduce bagasse moisture con-tent will improve the system performance. The use of parabolic trough collector to generate additional steam for steam dryer will enhance the capacity of steam dryer. In the paper, the cogeneration system integrated with steam dyer and parabolic trough collector is proposed. Simulation results from models of cogeneration system, boiler, steam dryer, and parabolic trough collector show that this system is capable of generating more power output than the cogeneration system without steam dyer and parabolic trough collector that consumes the same amount of fuel. The estimation of the payback period for the investment in steam dyer and parabolic trough collector is also provided.

Abstract

The treatment of antibiotic filter residue (AFR) is an important issue, because of its special nature, the large output, and the difficulty of combustion. Nowadays, the AFR is generally incinerated, but dioxins are produced during the process, which makes incineration technology face challenges. There is a lack of research on the influences of co-combustion conditions on temperature field and flue gas characteristics, but it plays an important role in practical applications. The present study aimed to investigate the influences of AFR mixed with biogas on furnace temperature field and emission characteristics through numerical simulation. The results showed that the opposed injection position was the best type when the proportion of mixed biogas was constant. The results can provide new insight into co-combustion and thermal utilization of AFR.