The influence of condenser pressure variation and tip leakage on
It is shown that accurately modelling the exit boundary calculation has a large influence on the flow structure and a smaller influence on the pressure recovery inside the
A study on the single screw expander with exhaust kinetic energy
1. Introduction. In recent years, with the growing energy crisis and environmental problems, more and more attention has been paid to developing new energy sources and the efficient use of energy [1], [2].The Organic Rankine Cycle (ORC) uses low boiling point organic mass, which can convert industrial waste heat, solar energy, geothermal energy,
Pressure and temperature response and phase transition path
Rapid pressure drop and slight rebound occur during the leakage process, and low initial pressure leads to a more pronounced pressure plateau effect. Dense-phase CO 2 leakage produced more dry ice than supercritical state, and the far field sublimation effect was more significant. In practice, particular attention should be paid to safety far
Atmospheric Pressure Dry Etching of Polysilicon Layers for Highly
efficiency potential of TOPCon-based solar cell architecture concept is already proven in laboratory scale solar cells by reaching V OC of up to 725mV and conversion efficiencies of 26.0% and more.[1,2] Moreover, initial industrial adaption of this technology by PV manufacturers also shows promising results.[3–5] Low pressure
Acoustic method of high-pressure natural gas pipelines leakage
It shows the whole process of leakage acoustic waves. The distribution trend of sound pressure at different monitoring points is the same. with the increase of frequency. The lower the frequency, the higher the energy. In addition, the farther away from the leak hole, the higher the energy level of low-frequency sound pressure (e.g., the
Hydrogen leaks at the same rate as natural gas in typical low-pressure
A global interest to increase the use of renewable resources has spurred an interest in hydrogen (H 2) gas as an energy carrier.Natural gas (NG) infrastructure has been proposed as a potential storage, transmission and distributions system for renewably produced gaseous H 2 fuel. Introducing H 2 to the NG system has raised concerns about H 2 leakage
Leakage current alleviation in solar energy conversion system
To solve the aforementioned issues, the harmonic compensation controller is presented herein to ensure the unity power factor operation, harmonic compensation, leakage
Based on abnormal fluctuations in user-side flow simulation
In the formula,φ represents the velocity coefficient under different states, which is 0.97~0.98 under general conditions. Q v is the theoretical volume flow rate of the leak port, m3/s; A φ represents the equivalent area of the leak outlet, which is generally the same as the measured area, m2; R is the gas constant.. When leak occurs, the theoretical flow rate at the
Quantitative assessment of the local leakage current in PV modules
In order to assess the local leakage current density dis-tribution in PV modules and the resulting possible local electrical power degradation we investigated the conductiv-ity of common
Pressure and temperature response and phase transition path
Rapid pressure drop and slight rebound occur during the leakage process, and low initial pressure leads to a more pronounced pressure plateau effect. Dense-phase CO 2
Fault Detection in Floating PV System Using DC Leakage Current
Due to the presence of water below the PV panels, the panel temperature will stay low and this effect can lead to increase in PV efficiency by 15% annually [1, 2]. But due to
Fine modification of reactively sputtered NiOX hole transport layer
The NiO X thin films have a lot of Ni atoms inside and show the metal properties i.e. low resistivity, very low TT, high TR and absorption. The increasing of the deposition rate with increasing O 2 gas fluxes in Zone 1 is mainly due to the increasing target voltage enhancing sputtering yield even though the NiO has a lower sputtering yield as compared to Ni.
A new real-gas model to characterize and predict gas leakage
Traditional ideal-gas models with the assumption of fully ruptured leak loss are valid for a large leak hole in low-pressure gas pipelines (3–14 bar). In the light of prediction accuracy, the new real-gas model shows its advantage over the traditional ideal-gas model, the improved ideal-gas model, and the semi-empirical correlation
Jet impingement cooling applications in solar energy
Two types of energy can be obtained from solar energy: Solar thermal (heat) and photovoltaic (electricity). Solar thermal is the heat that is extracted from the solar collector, a device that captures the heat from the sun''s energy. In comparison, photovoltaics generates electricity from solar energy.
Recent progress towards solar energy integration into low-pressure
Although the energy demand of nitrogen production is one magnitude lower than of the hydrogen production, it should not be neglected either, especially since the produced nitrogen must be extremely pure, allowing only a few ppm of residual O 2 to avoid the poisoning of the catalyst in the Haber-Bosch process. Similar purities are required for most low-pressure
SL2020-707 Fuel leakage from high-pressure pipes and low-pressure
Fuel leakage – from high-pressure pipes and. low-pressure circulation lines SL2020-707/KNB. December 2020 Concerns. Owners and operators of MAN B&W two-stroke marine diesel engines. Type: All MAN B&W engines Summary. Never remedy an oil leakage by retightening the union nipples. Regularly inspect the low-pressure circulation line for damage and
Leak Detection Using Pressure Transmitters for Pipeline Networks
Abstract. With increasing environmental concerns, regulatory and CSA Z662-23 standard requirements [1], leak detection in all pipelines has become a top priority for the energy industry in recent years. Real time leak detection on the upstream pipeline gathering networks carrying emulsions from oil wells to separation facilities is very challenging due to the
Effects of ventilation on leakage and diffusion law of gas pipeline
Computational fluid dynamics (CFD) method, as a method for calculating fluid motion, is widely used in the study of gas leakage and diffusion (Horvat, 2018, Tianpei et al., 2018, Choi et al., 2013, Hanna et al., 2009, Hua et al., 2020).Ebrahimi-Moghadam et al. (2018) carried out the CFD analysis of gas leakage and diffusion and the correlation development of
Journal of Energy Storage
Within the range of 0.02–0.05 mm, as the radial clearance increases, the mass flow of the tangential leakage gas increases, and the leakage gas in the low-pressure chamber is repeatedly compressed, which leads to the decrease in the average mass flow of inlet and outlet.
Theoretical insight into leakage current of solar module under
In photovoltaic power station, the solar cells in the module are exposed to positive or negative bias, which will lead to leakage current between the frame and
Chapter 7 Leakage Current in Solar Photovoltaic Modules
An increase in the share of solar energy may destabilize the grid. To overcome the issues of grid instability, specifically in remote areas, BIM and GIS-based microgrid planning based on data
A measured energy use, solar production, and building air leakage
This paper provides an open dataset of measured energy use, solar energy production, and building air leakage data from a 328 m 2 (3,531 ft 2) all-electric, zero energy commercial building in Virginia, USA. Over two years of energy use data were collected at 1-hour intervals using circuit-level energy monitors.
High pressure hydrogen leakage diffusion: Research progress
The leakage diffusion behaviour of hydrogen is an important prerequisite for the study of hydrogen chain combustion. Therefore, based on previous studies, this paper reviews the research methods and their influencing factors for the leakage-diffusion transport of high-pressure hydrogen occurring during transport and use, and presents and summarises the influence of
Energy Star V3 Building Science
leakage in the building envelope or the ducting, or an imbalance in the supply and return ducts can cause these fans to have a drastic efect. While natural forces (wind and stack) produce between one and ten Pascals of pressure on residential buildings, fans can produce as high as 60 Pascals of pressure. Exhaust Fans
Experimental studies on solar multi
Fig. 2 shows the bird''s-eye view of Solar MED system. The solar thermal FPC field is tested for pressure of 4 bar in order to check leakage by following the standard testing procedure. The entire MED plant is tested under vacuum pressure of 30 mbar to check vacuum leakage. Heat as an energy source is often associated with low grid energy
Recent Advances in Hole-Transporting Layers for
Schematic structure of conventional and inverted OSCs, and a simplified view of the operating principle in the active layer. The current-voltage (J-V) curve of an OSC is characterized under 1000 W/m 2 light of AM 1.5 solar spectrum [].
Numerical simulation study on the leakage and diffusion
In order to realize the full potential of hydrogen energy, storage is a key issue [11].Currently, there are various methods available for hydrogen storage, such as high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, low-temperature compression hydrogen storage [12], as well as material-based hydrogen storage methods like
Leakage detection of low-pressure gas distribution pipeline
For nearly a century, natural gas has been the main energy source of the world''s major economies [1, 2].The main reason is that natural gas is recognized as the cleanest low-carbon fossil energy [3, 4]and plays an irreplaceable role in the integrated energy system [5].The huge natural gas market mainly relies on complex pipeline network to connect
Analysis on Influence Factors of Differential Pressure Detection of
pieces with large leakage. The direct pressure detection method refers to that the measured workpiece is filled with a certain pressure of gas. If there is leakage, the pressure in the cavity will drop after a certain time of reaction. The detection method has the advantages of simple operation, low cost, and fast detection, but limited by the
International Journal of Hydrogen Energy
As an efficient and carbon-free energy carrier, at a distance of 12 mm from the hole, the low-pressure region appears in the diagonal plane, while the opposite is true in the 15 mm image. According to previous studies [20], expansion fans are generated along each edge of the leak hole, at the corners of the leak hole, the two expansion fans
Photocatalytic water splitting for large-scale solar-to-chemical energy
Oxyhydrogen has a low ignition threshold energy, ignites by itself in a region of high temperature and high pressure, and ignition leads to detonation (propagation of a combustion shock wave), depending on the size and shape of the containing vessel. The safe operation of OWS photocatalysts therefore requires the establishment of design criteria for gas-handling
Leakage, diffusion and distribution characteristics of refrigerant in
The equations of the gas at the leakage hole in sonic and subsonic flow states were as follows: (2) CPR = p a p cr = 2 k + 1 k k-1 Q = ξ A or p 1 M a 1 kM ZR T 1 = ξ A or p 2 kM ZR T 2 p 1 ⩾ p cr The gas is in sonic flow state Q = ξ A or 2 M R k k-1 T 2-T 1 T 1 p 1 2-T 2 p 2 2 p 1 < p cr The gas is in subsonic flow state Where p a is the atmospheric pressure of the
A New Model for Predicting Characteristics of the Near-Field Leakage
In recent years, researchers have increasingly focused on minor CO₂ pipeline leakage.(Woolley et al., 2014; Pham and Rusli, 2016a; C.-Y. Li et al., 2023) During CO₂ leakage, the sudden pressure drop causes fluid to rapidly expand to adapt to the lower ambient pressure.( Gu et al., 2019) The gas flow undergoes expansion and acceleration outside the leakage hole,
Leakage current alleviation in solar
In this study, a three-phase SECS is presented herein to ameliorate the PQ of the grid and to suppress the leakage current. In the state-of-the-art literature [], the
High‐pressure under‐expanded hydrogen leakage model
Mengxiao found that the hydrogen leakage from the high-pressure pipeline crack or nozzle leakage belongs to the high-pressure under-expanded jet. 16 According to the different pressure ratios, the jet states can be divided into three types, that is, subsonic jet, isosonic jet, and under-expanded ultrasonic jet. 17 Subsonic jets are usually used to predict
Migration and phase change study of leaking molten salt in tank
Molten salt has the advantages of a large specific heat and energy density, a low vapor pressure and melting point, and thermal chemistry stability [1], [2], and molten salt is widely used as a heat transfer and thermal storage medium in concentrated solar power (CSP) plants and other industrial systems.During the application process, the environmental pollution from
Overview of Failure Mechanisms and PV Qualification Tests
The combination of the high leakage rates and the reduced HTF-proof performance of the insulation facilitates the soaking of the insulation porous materials in HTF
Aerodynamic performance change of exhaust passage in steam
The pressure loss ratio of throat (γ T) is the percentage of the total pressure drop in throat to the total pressure drop in the exhaust passage: (17) γ T = p t, 2 − p t, out Δ p × 100 % (18) γ D + γ V + γ T = 100 % Where p t, 1 is the mass average total pressure at the diffuser outlet (i.e. the volute inlet), Pa. p t, 2 is the mass average total pressure at the throat inlet (i.e. the