scholarly journals Optimization of a H2 Liquefaction Pre-Cooling Process & Estimate of Liquefaction Performance with Varying Ambient Temperature

2021 ◽  
Author(s):  
Steven Jackson ◽  
Eivind Brodal
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Heat Sink ◽  
Design Parameters ◽  
Ambient Conditions ◽  
Cooling Process ◽  
Transportation Capacity ◽  
Energy Penalty ◽  
Liquefaction Process ◽  
Heat Sink Temperature

Hydrogen used as an energy carrier can provide an important route to the decarbonization of energy supplies. However, realizing this opportunity requires a significant increase in both production and transportation capacity. Part of the increase in transportation capacity could be provided by the shipping of liquid hydrogen, but this introduces an energy-intensive liquefaction step into the supply-chain. The energy required for liquefaction can be reduced by developing improved process designs, but since all low-temperature processes are affected by the available heat-sink temperature, local ambient conditions will also affect the energy penalty. This work studies how the energy consumption associated with liquefaction varies with heat-sink temperature through the optimization of design parameters for a typical next-generation hydrogen liquefaction process. The results show that energy consumption increases by around 20%, across the cooling temperature range 5 to 50 °C. Considering just the range 20 to 30 °C there is a 5% increase, illustrating the significant impact ambient temperature can have on energy consumption.

scholarly journals Optimization of a Mixed Refrigerant Based H2 Liquefaction Pre-Cooling Process and Estimate of Liquefaction Performance with Varying Ambient Temperature

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6090
Author(s):  
Steven Jackson ◽  
Eivind Brodal
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Heat Sink ◽  
Design Parameters ◽  
Ambient Conditions ◽  
Cooling Process ◽  
Transportation Capacity ◽  
Liquefaction Process ◽  
The Impact ◽  
Heat Sink Temperature

Hydrogen used as an energy carrier can provide an important route to the decarbonization of energy supplies, but realizing this opportunity will require both significantly increased production and transportation capacity. One route to increased transportation capacity is the shipping of liquid hydrogen, but this requires an energy-intensive liquefaction step. Recent study work has shown that the energy required in this process can be reduced through the implementation of new and improved process designs, but since all low-temperature processes are affected by the available heat-sink temperature, local ambient conditions will also have an impact. The objective of this work is to identify how the energy consumption associated with hydrogen liquefaction varies with heat-sink temperature through the optimization of design parameters for a next-generation mixed refrigerant based hydrogen liquefaction process. The results show that energy consumption increases by around 20% across the cooling temperature range 5 to 50 °C. Considering just the range 20 to 30 °C, there is a 5% increase, illustrating the significant impact ambient temperature can have on energy consumption. The implications of this work are that the modelling of different liquified hydrogen based energy supply chains should take the impact of ambient temperature into account.

scholarly journals Optimization of the CO2 Liquefaction Process-Performance Study with Varying Ambient Temperature

2019 ◽  
Vol 9 (20) ◽  
pp. 4467 ◽  
Author(s):  
Steven Jackson ◽  
Eivind Brodal
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Minimum Energy ◽  
Attractive Alternative ◽  
System Modelling ◽  
Efficient Design ◽  
Performance Study ◽  
Cooling Temperature ◽  
Minimum Energy Consumption ◽  
Liquefaction Process

In carbon capture utilization and storage (CCUS) projects, the transportation of CO2 by ship can be an attractive alternative to transportation using a pipeline, particularly when the distance between the source and usage or storage location is large. However, a challenge associated with this approach is that the energy consumption of the liquefaction process can be significant, which makes the selection of an energy-efficient design an important factor in the minimization of operating costs. Since the liquefaction process operates at low temperature, its energy consumption varies with ambient temperature, which influences the trade-off point between different liquefaction process designs. A consistent set of data showing the relationship between energy consumption and cooling temperature is therefore useful in the CCUS system modelling. This study addresses this issue by modelling the performance of a variety of CO2 liquefaction processes across a range of ambient temperatures applying a methodical approach for the optimization of process operating parameters. The findings comprise a set of data for the minimum energy consumption cases. The main conclusions of this study are that an open-cycle CO2 process will offer lowest energy consumption below 20 °C cooling temperature and that over the cooling temperature range 15 to 50 °C, the minimum energy consumption for all liquefaction process rises by around 40%.

Steady State Modeling of LHP and Analysis

2010 ◽  
Author(s):  
Yan Chen ◽  
Lin Cheng ◽  
Gongming Xin ◽  
Tao Luan
Keyword(s):  
Steady State ◽  
Ambient Temperature ◽  
Heat Pipe ◽  
Heat Sink ◽  
Heat Load ◽  
Operating Temperature ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Heat Sink Temperature ◽  
Transition Heat

The loop heat pipe (LHP) was invented in Russia in the early 1980’s. It is a two-phase heat transfer device that utilizes the evaporation and condensation of a working fluid to transfer heat, and the capillary force developed in fine porous wicks to circulate the fluid. The temperature of LHP evaporator as functions of the heat load, sink temperature, ambient temperature is an important parameter which can reflect the performance of an LHP. Many factors can affect the LHP operating temperature and which can be divided into two parts: external and internal. The external factors including heat sink temperature, ambient temperature, fluid forces, the position between heat source and heat sink and the heat exchange between LHP and ambient. The internal factors related to the design and structure of the LHP, for example, the charging amount of the working fluid and the distribution status of the liquid phase during the LHP operating. Based on Sinda/Fluint software an ammonia-stainless steel steady state model of loop heat pipe was established, the impacts on the LHP operating temperature induced by alterable heat loads under 3 operating cases (the different position between evaporator and condenser, the changing of ambient temperature and the changing of heat sink temperature) were analyzed and conclusions were made. Changing the position between evaporator and condenser has a significant influence on the LHP operating temperature. Anti-gravity operation will reduce the performance of the LHP, this phenomenon is obviously in low heat load range. Further more, increasing of fluid pressure drop in the loop will induce decreasing of the LHP performance. The temperature difference between ambient and heat sink will influence the transition heat load (from variable conductance mode to fixed conductance mode), the bigger the temperature difference the higher the transition heat load.

scholarly journals Optimization of the CO2 Liquefaction Process - Performance Study with Varying Ambient Temperature

2019 ◽  
Author(s):  
Steven Jackson ◽  
Eivind Brodal
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Minimum Energy ◽  
Attractive Alternative ◽  
System Modelling ◽  
Performance Study ◽  
Cooling Temperature ◽  
Minimum Energy Consumption ◽  
Wide Range ◽  
Liquefaction Process

In CCS projects, the transportation of CO2 by ship can be an attractive alternative to transportation using a pipeline, particularly when the distance between source and disposal location is large. However, the energy consumption of the liquefaction process can be significant, making the selection of an energy-efficient design an important factor in the minimization of operating costs. Since the liquefaction process operates at low temperature, its energy consumption will vary with ambient temperature, which could be a factor that influences the trade-off point between pipelines and shipping in different geographic locations. A consistent set of data showing the relationship between energy consumption and cooling temperature is therefore potentially useful to CCS system modelling. This study compares the performance of a wide range of CO2 liquefaction schemes. It applies a methodical approach to the optimization of process operating parameters and studies performance across a range of operating temperatures. A set of data for the minimum energy consumption cases is presented. The main findings are that open-cycle CO2 processes often offer minimum energy consumption; NH3 based schemes often offer better performance at higher ambient temperatures; and that for the cooling temperature range 15 to 50 °C, the energy consumption for the best performing liquefaction process rises by around 40%.

Evaluation the effect of the ambient temperature on the liquid petroleum gas transportation pipeline

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ammar Ali Abd ◽  
Samah Zaki Naji ◽  
Ching Thian Tye ◽  
Mohd Roslee Othman
Keyword(s):  
Energy Consumption ◽  
Greenhouse Gases ◽  
Ambient Temperature ◽  
Phase Change ◽  
Liquid State ◽  
Pump Energy ◽  
Compressible Liquid ◽  
Liquefied Petroleum Gas ◽  
Efficient Design ◽  
The Impact

Abstract Liquefied petroleum gas (LPG) plays a major role in worldwide energy consumption as a clean source of energy with low greenhouse gases emission. LPG transportation is exhibited through networks of pipelines, maritime, and tracks. LPG transmission using pipeline is environmentally friendly owing to the low greenhouse gases emission and low energy requirements. This work is a comprehensive evaluation of transportation petroleum gas in liquid state and compressible liquid state concerning LPG density, temperature and pressure, flow velocity, and pump energy consumption under the impact of different ambient temperatures. Inevitably, the pipeline surface exchanges heat between LPG and surrounding soil owing to the temperature difference and change in elevation. To prevent phase change, it is important to pay attention for several parameters such as ambient temperature, thermal conductivity of pipeline materials, soil type, and change in elevation for safe, reliable, and economic transportation. Transporting LPG at high pressure requests smaller pipeline size and consumes less energy for pumps due to its higher density. Also, LPG transportation under moderate or low pressure is more likely exposed to phase change, thus more thermal insulation and pressure boosting stations required to maintain the phase envelope. The models developed in this work aim to advance the existing knowledge and serve as a guide for efficient design by underling the importance of the mentioned parameters.

The Simulation Experiments Research of Plow Bit Cutting Coal Rock Basing on Ls-Dyna

2011 ◽  
Vol 228-229 ◽  
pp. 1035-1038
Author(s):  
Zhi Yong Hao ◽  
Jun Mao
Keyword(s):  
Energy Consumption ◽  
Coal Seam ◽  
Separation Distance ◽  
Design Parameters ◽  
Cutting Depth ◽  
Element Analysis ◽  
Cutting Resistance ◽  
Cutting Energy ◽  
3D Simulation Model ◽  
Depth Separation

Using finite element analysis software ANSYS/ LS-DYNA, establishing the plow cutting coal seam 3D simulation model, simulating plow bit cutting coal seam dynamic process. under study, obtaining plow bit the cutting resistance, plow speed of time process curve, analyzing the influence on cutting energy consumption of the different cutting depth, separation distance and width, reaching the rule of cutting energy consumption changing with plow bits’ structure parameter and design parameters, in order to reduce the energy consumption and resistance, cutting depth and plow bits spacing ought to be selected by the real coal seam face conditions.

scholarly journals A Comparative Analysis of Thermoelectric Modules for the Purpose of Ensuring Thermal Comfort in Protective Clothing

2021 ◽  
Vol 11 (17) ◽  
pp. 8068
Author(s):  
Anna Dąbrowska ◽  
Monika Kobus ◽  
Bartosz Pękosławski ◽  
Łukasz Starzak
Keyword(s):  
Heat Flux ◽  
Ambient Temperature ◽  
Heat Sink ◽  
Protective Clothing ◽  
Phase Change Materials ◽  
Thermoelectric Module ◽  
Thermoelectric Modules ◽  
Cooling Function ◽  
A Tec ◽  
Flexible Thermoelectric

In recent times, more and more workers are exposed to thermal stress due to climate changes and increased ambient temperature. Demanding physical activities and the use of protective clothing are additional sources of thermal load for workers. Therefore, recent research has focused on the development of protective clothing with a cooling function. Phase change materials, air or liquid, were mainly used for this purpose; only a few publications were concerned the use of thermoelectric modules. This publication analyzes the influence of such factors as supplied current, ambient temperature, and the type of heat sink on the amount of heat flux transferred by a thermoelectric cooler (TEC) and the electric power consumed by it. In the course of laboratory tests, a flexible thermoelectric module and three heat sink variants were tested. For this purpose, a polymer TEGway heat sink, a metal one, and a self-made one based on a superabsorbent were used. The research showed that at a temperature of 30 °C and above, the amount of the heat flux transferred by a TEC with a total area of 58 cm2, and an active area of 10 cm2 should be expected to be from 1 W to 1.5 W. An increase in ambient temperature from 20 to 35 °C caused a significant reduction in the heat flux by about 1 W. The results obtained indicated that the type of heat sink affects the heat flux drawn by the TEC to a statistically significant extent. The heat sink using the evaporation effect turned out to be the most efficient.

Improved Design Parameters for a Liquid Desiccant Dehumidifier in Confined Spaces

Solar Energy ◽  
2005 ◽  
Author(s):  
D. Dong ◽  
M. Liu
Keyword(s):  
Energy Consumption ◽  
Ventilation System ◽  
Exhaust System ◽  
Design Parameters ◽  
Confined Space ◽  
Confined Spaces ◽  
Exhaust Ventilation ◽  
Moisture Condensation ◽  
Improved Design ◽  
Control Application

Investigations of a desiccant dehumidifier system have been performed for humidity control application in confined spaces. A previous study revealed that the base dehumidifier system can reduce moisture condensation by 22% over a conventional exhaust ventilation system. The current study aims to develop improved design requirements for a desiccant dehumidifier. The energy consumption of an exhaust ventilation system and an improved dehumidifier system was compared. To investigate the improved desiccant dehumidification system, numerical simulations were conducted and an objective function was established. This paper presents simulated results for an existing desiccant dehumidification system and an improved system, in which improved parameters are used. Use of the improved design parameters can reduce moisture condensation by 26.6% over a base dehumidifier system and shorten the dehumidifier performance period by 14%. Energy consumption with the sole use of an exhaust system is compared with that of the improved dehumidifier system under the same conditions. The results show that energy consumption can be substantially reduced, by 63%, in the improved dehumidifier system with the same amount of moisture condensation on surfaces of the confined space.

Migration-assisted, moisture gradient process for ultrafast, continuous CO2 capture from dilute sources at ambient conditions

2022 ◽  
Author(s):  
Aditya Prajapati ◽  
Rohan Sartape ◽  
Tomás Rojas ◽  
Naveen K. Dandu ◽  
Pratik Dhakal ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Electric Field ◽  
Co2 Capture ◽  
Moisture Gradient ◽  
Low Energy ◽  
Ambient Conditions ◽  
Capture Process ◽  
Low Energy Consumption

An ultrafast, continuous CO2 capture process driven by moisture gradient and electric field with low energy consumption to capture and concentrate CO2 from dilute sources.

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