Andriyanto Setyawan^a,*

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-6, 2020, DOI:10.5098/hmt.14.22

Abstract In this paper, the effect of evaporating temperature on the void fraction and flow pattern of R290 in an evaporator of air conditioning unit has been studied. The analysis was carried out for evaporator diameter of 7.9 mm and 6.3 mm and cooling capacity of 2.64 kW and 5.28 kW. The analysis was conducted at evaporating temperature of -20°C to +5°C with an increment of 5°C. At the inlet of evaporator, the void fraction ranges from 0.932 to 0.984, whereas at the outlet the void fraction is 1. Testing the void fraction by using 3 available correlations gives the good… More >

Jing Hu^a,* , Mingxing Du^b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-7, 2020, DOI:10.5098/hmt.14.5

Abstract Inert gases are conveniently used for leak detection. Relative to CO₂, majority of the inert gases are non-condensable. It is of great significance to understand the effects of residual non-condensable gases on the performance of a refrigeration system. This paper investigates, both theoretically and experimentally, on the impact of residual non-condensable gases on the performance of a carbon dioxide (CO₂) evaporator and the system performance. A theoretical analysis indicates that residual non-condensable gases can convert homogeneous nucleation into a heterogeneous nucleation process and accelerate phase change, thus, reducing superheat or incipient boiling temperature. To investigate the influence of residual non-condensable… More >

Zhenfang Liu^*, Haibo Liu, Dongmei Zhang

Energy Engineering, Vol.120, No.7, pp. 1717-1727, 2023, DOI:10.32604/ee.2023.027968

Abstract To improve the operation efficiency of the photovoltaic power station complementary power generation system, an optimal allocation model of the photovoltaic power station complementary power generation capacity based on PSO-BP is proposed. Particle Swarm Optimization and BP neural network are used to establish the forecasting model, the Markov chain model is used to correct the forecasting error of the model, and the weighted fitting method is used to forecast the annual load curve, to complete the optimal allocation of complementary generating capacity of photovoltaic power stations. The experimental results show that this method reduces the average loss of photovoltaic output… More >

Luqian Zhang^1,#, Xilin Fang^1,#, Nan Yu¹, Jun Chen¹, Haodong Wang¹, Quansheng Shen¹, Guanghui Chen^2,*, Yue Wang^1,*

Phyton-International Journal of Experimental Botany, Vol.92, No.5, pp. 1571-1587, 2023, DOI:10.32604/phyton.2023.025481

Abstract Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings. Melatonin has been proven to play an important role in alleviating plant stress. However, its effect on seed germination under drought conditions is still poorly understood. Therefore, we studied the effects of melatonin on rice seed germination and physiological characteristics under drought stress. Rice seeds were treated with different concentrations of melatonin (i.e., 0, 20, 100, and 500 μM) and drought stress was simulated with 5% polyethylene glycol 6000 (PEG6000). The results showed that 100 μM melatonin can effectively improve the germination potential,… More >

Daoming Shen^1,*, Jinhong Xia¹, Chao Gui¹, Songtao Xue²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1863-1873, 2023, DOI:10.32604/fdmp.2023.024925

Abstract In order to ensure the safe operation of the compressors used in water chillers, in the present study some interlock protections have been added to the related design. These include a low pressure protection, a high pressure protection, an exhaust temperature protection and a differential pressure protection. Some tests have been conducted by tuning the saturation suction and exhaust temperatures of the compressor through adjustment of the cold source outlet temperature and the ambient temperature. The results show that the ambient temperature increases with decreasing device load and increasing fan speed under the same saturated suction temperature; the device refrigerating… More > Graphic Abstract

Fuyin Ni^1,2, Kai Li^2,*

Energy Engineering, Vol.120, No.5, pp. 1203-1221, 2023, DOI:10.32604/ee.2023.025796

Abstract Unified power quality conditioner (UPQC) with energy storage is commonly based on conventional capacity configuration strategy with power angle control. It has problems such as phase jumping before and after compensation. DC-link cannot continuously emit active power externally. Therefore, this paper presents the compensation strategy of full load voltage magnitude and phase in capacity configuration of UPQC. The topology of UPQC is integrated a series active power filter (SAPF), a shunt active power filter (PAPF) and a photovoltaic-battery energy storage system (PV-BESS). The principle of full load voltage compensation is analyzed based on the PV-BESS-UPQC topology. The magnitude constant of… More > Graphic Abstract

Wei Xiong^1,2, Dagang Li^1,*, Peixing Wei², Lin Wang², Qian Feng¹

Journal of Renewable Materials, Vol.11, No.5, pp. 2265-2278, 2023, DOI:10.32604/jrm.2023.025483

Abstract Poplar wood, which was used as the absorption material for the solar-driven interfacial evaporation, was treated for 3 days, 6 days and 9 days with the pectinase, and then was simulated for photothermal evaporation test at one standard solar radiation intensity (1 kW⋅m⁻²). The effects of pectinase treatment on cell passage and water migration capacity of poplars were analyzed by the mercury intrusion porosimetry, the scanning electron microscope and fractal theory. It was found that the pit membrane and the ray parenchyma cells of poplar wood were degraded and destroyed after pectinase treatment. Compared with the untreated poplar wood, the evaporation… More >

Yan Wang¹, Zhicheng Ma², Jinping Zhang², Qiang Zhou², Ruiping Zhang¹, Haiying Dong^1,*

Energy Engineering, Vol.120, No.4, pp. 949-963, 2023, DOI:10.32604/ee.2023.025668

Abstract Because of the randomness of wind power and photovoltaic (PV) output of new energy bases, the problem of peak regulation capability and voltage stability of ultra-high voltage direct current (UHVDC) transmission lines, we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work. Firstly, we established the uncertainty model of wind power and PV based on the chance constrained planning theory. Then we used the K-medoids clustering method to cluster the scenarios considering the actual operation scenarios throughout the year. Secondly, we established the optimal configuration model based on… More >

Lei Xing¹, Yakui Liu^2,3,*

Energy Engineering, Vol.120, No.4, pp. 1023-1043, 2023, DOI:10.32604/ee.2023.025335

Abstract The optimal allocation of integrated energy system capacity based on the heuristic algorithms can reduce economic costs and achieve maximum consumption of renewable energy, which has attracted many attentions. However, the optimization results of heuristic algorithms are usually influenced by the choice of hyperparameters. To solve the above problem, the particle swarm algorithm is introduced to find the optimal hyperparameters of the heuristic algorithms. Firstly, an integrated energy system consisting of the photovoltaic, wind turbine, electrolysis cell, hydrogen storage tank, and energy storage is established. Meanwhile, the minimum economic cost, the maximum wind and PV power consumption rate, and the… More >

Ahmad A. Mohammad^*

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 1139-1156, 2023, DOI:10.32604/cmc.2023.035964

Abstract Exploiting modification direction (EMD) based data hiding techniques (DHTs) provide moderate data hiding capacity and high-quality stego images. The overflow problem and the cyclic nature of the extraction function essentially hinder their application in several fields in which reversibility is necessary. Thus far, the few EMD reversible DHTs are complex and numerically demanding. This paper presents a novel EMD-based reversible DHT using dual-image. Two novel 2 × 4 modification lookup tables are introduced, replacing the reference matrix used in similar techniques and eliminating the numerically demanding search step in similar techniques. In the embedding step, one of the modification tables modifies a… More >