Cooling Temperature Research Articles

Nonlinear Oxidation Behavior at Interfaces in Coated Steam Dual-Pipe with Initial Waviness and Cooling Temperature

A numerical simulation method is proposed to investigate the nonlinear growth of thermally grown oxide (TGO) on a novel coated steam dual-pipe system operating at 700 °C. Utilizing oxidation kinetics data from high-temperature water vapor experiments, the study examines interface stresses and morphology evolution, considering initial surface waviness and cooling temperature effects. The findings indicate that the parabolic law accurately describes the nonlinear growth of TGO during high-temperature water vapor oxidation, with the TGO growth oxidation rate constant being 4.5×10−4μm2/h. The growth rate of TGO thickness decreases with increasing oxidation duration. Stress concentrations are found to develop at TGO interfaces, particularly in regions with high curvature, and those with elevated wavy amplitudes. The primary factor influencing stress redistribution and morphology evolution is the wavy amplitude of the TGO. Additionally, variations in cooling temperature affect interface stresses along the axial direction of the pipe system during nonlinear oxidation, resulting in relatively minor changes in morphology.

Influence of the Cooling Temperature on the Surface Quality in Integrated Additive and Subtractive Manufacturing of Aluminum Alloy.

The surface quality of parts processed by laser additive manufacturing, especially laser-based directed energy deposition (LDED), makes it difficult to meet actual use requirements. In addition, defects generated during the long-term additive manufacturing process need to be removed in time. Therefore, laser additive and subtractive manufacturing is of great significance for additive manufacturing. The main difference between laser additive-subtractive manufacturing and pure subtraction is that a cooling temperature is required due to the laser process. Therefore, this work studies the temperature variation regularity during LDED and the milling processes, as well as the surface roughness, cross-sectional microstructure, and tool wear under different cooling temperatures for milling. The results show that there is a "turning point temperature" in LDED, and the value of the turning point temperature gradually increases with heat accumulation, which affects the initial temperature of the subtractive manufacturing. When subtracting, a high initial temperature improves surface quality and reduces tool wear, but an excessively high temperature will cause the aluminum alloy to adhere to the tool. Then, the smear metal is difficult to effectively remove, deteriorates the milling quality, and aggravates tool wear. It is found that the higher the cooling temperature generated, the wider the thermally insulated shear band. The insulated shear band may affect the quality of the additive and subtractive manufacturing. Finally, it is determined that the milling temperature of aluminum alloy in this work condition is about 100 °C.

A probabilistic assessment of ship blackout incident with Fault Tree Analysis into (FTA) Bayesian Network (BN)

Blackouts in maritime activities can cause propulsion loss and dangerous maritime conditions. Bayesian risk analysis is applied to ship blackout incidents in this study to improve understanding and reduce risks. Using Fault Tree Analysis (FTA), a Bayesian Network (BN) model incorporates fuel quality, lubricating oil quality, sensor error, injector error, and mechanical defects to estimate blackout probability. The model analyses how hazards and their interactions affect this situation using probabilistic inference. Sensitivity analysis identifies variables that affect blackout probabilities and prioritises risk mitigation solutions. Based on prior and posterior probabilities, ‘Automatic Voltage Regulator Failure’ (0.03 prior, 0.17 posterior), ‘Rotor Mechanical Fault’ (0.03 prior, 0.15 posterior), and ‘High Cooling Water Temperature’ (0.03 prior, 0.13 posterior) are the top three blackout causes. Other significant variables include ‘Switchboard Line Failure,’ ‘Faulty Fuel Pump,’ ‘Rotor Open Circuit,’ and ‘Temperature Sensor Failure’ in relative amounts. Bayesian risk analysis can identify and minimise marine blackout concerns, giving decision-makers a comprehensive framework for informed decision-making and proactive risk management. This research emphasises blackout accidents’ importance, improving maritime transportation safety and reliability.

Relative Cooling Power and Temperature Averaged Entropy Change in La₁.₃₄Sr₁.₆₆Mn₂O₇: Magnetocaloric Effects

Relative Cooling Power and Temperature Averaged Entropy Change in La₁.₃₄Sr₁.₆₆Mn₂O₇: Magnetocaloric Effects

Role of Cooling Temperature on Impurities Precipitation of Metal Sulfate Solution Derived from Crude Ferronickel Leaching Using MgO

Nickel is used as a raw material for Nickel Manganese Cobalt (NMC) batteries as a compound of Nickel Sulphate Hexahydrate (NiSO4.6H2O). This study used nickel laterite as ore. A hydrometallurgical process carries out Ferronickel to extract nickel concentrate. The first step is leaching using 2M H2SO4 solution for 6 hours with a stirring speed of 200 rpm at 90°C. The leached solution was then neutralized using a neutralizing agent MgO 5% w/w until it reached a pH of 3.5. The neutralized filtrate was then filtered to separate the filtrate and the residue. The neutralization process produces magnesium sulfate salt (MgSO4), which is an impurity. Next, the cooling temperature method is used to precipitate MgSO4 crystals. In this study, the variation of the MgSO4 cooling temperature used was -5, 0, and 5 °C. Subsequently, crystallization was carried out to produce NiSO4.6H2O. The highest nickel recovery (59.61%) can be achieved using a cooling temperature of -5 °C. Also, by using -5 °C of cooling temperature, the nickel content of crystal product is 2.75%. The crystallization product still contains other compounds, such as MgSO4, FeSO4, and CoSO4.

Numerical Investigation of the Effect of Changes in Glass Typeon the Cooling Load in a Building

Solar radiation enters the building through the glass by both radiation and conduction. The heat passing through the glass is one of the largest cooling loads. Therefore, modifying the glass type, will potentially reduce the cooling load significantly. This numerical study uses Cooling Load Temperature Difference (CLTD) method to calculate the change in cooling load in a five-story hospital. The Glass material was changed from clear glass to coated glass. Based on the calculation of cooling load per hour, from 07.00 to 19.00, it is obtained that the peak load occurs at 17.00, both when using clear glass clear and coated glass. The replacement of clear glass with coated glass results in a 70.0% decrease in radiation cooling load, from 104.59 kW to 31.38 kW. In addition, replacing this type of glass will reduce the total cooling load by 17.0%, from 418.80 kW to 347.57 kW. The decrease in total cooling load will lead to a decrease in the operational cost of the air conditioning system. If it is assumed that the AC system operates at 75% peak load for 16 hours per day, then replacing the glass will reduce electricity costs by approximately Rp. 43.6 million/month.

Enhancing COP and Cooling Temperature for Peltier with Decreasing Power, and Chemical Composition Negative Effect by Optimizing Connection, Position Angle, and Voltages

Enhancing COP and Cooling Temperature for Peltier with Decreasing Power, and Chemical Composition Negative Effect by Optimizing Connection, Position Angle, and Voltages

Time to Reaching Target Cooling Temperature and 2-year Outcomes in Infants with Hypoxic-Ischemic Encephalopathy

To determine if time to reaching target temperature (TT) is associated with death or neurodevelopmental impairment (NDI) at 2years of age in infants with hypoxic-ischemic encephalopathy (HIE). Newborn infants ≥36weeks of gestation diagnosed with moderate or severe HIE and treated with therapeutic hypothermia were stratified based on time at which TT was reached, defined as early (ie, ≤4hours of age) or late (>4hours of age). Primary outcomes were death or NDI. Secondary outcomes included neurodevelopmental assessment with Bayley Scales of Infant and Toddler Development, third edition (BSID-III) at age2. Among 500 infants, the median time to reaching TT was 4.3 hours (IWR, 3.2-5.7 hours). Infants in early TT group (n=211 [42%]) compared with the late TT group (n=289 [58%]) were more likely to be inborn (23% vs 13%; P<.001) and have severe HIE (28% vs 19%; P=.03). The early and late TT groups did not differ in the primary outcome of death or any NDI (adjusted RR,1.05; 95% CI,0.85-0.30; P=.62). Among survivors, neurodevelopmental outcomes did not differ significantly in the 2 groups (adjusted mean difference in Bayley Scales of Infant Development-III scores: cognitive, -2.8 [95% CI,-6.1 to 0.5], language -3.3 [95% CI,-7.4 to 0.8], and motor -3.5 [95% CI,-7.3 to 0.3]). In infants with HIE, time to reach TT is not independently associated with risk of death or NDI at age 2years. Among survivors, developmental outcomes are similar between those who reached TT at <4 and ≥4 hours of age. High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL); NCT02811263; https://beta. gov/study/NCT02811263.

Cooling Rate of Hot Stamping Dies by Constructed Cooling Temperature Trend Model

Cooling Rate of Hot Stamping Dies by Constructed Cooling Temperature Trend Model

The Effect of Cooling Temperature on Microstructure and Mechanical Properties of Al 6061-T6 Aluminum Alloy during Submerged Friction Stir Welding

Submerged friction stir welding (SFSW) is a new modification of friction stir welding. In this paper, 6 mm thick 6061Al-T6 alloy plates were welded using the friction stir technique under normal air and submerged water conditions at 108 mm/min welding speeds and a rotational rate of 900 rpm. The cooling water temperature in SFSW varied at 0 °C, 35 °C, and 80 °C to clarify the effect of water temperature. The characteristic hourglass-shaped stir zone was observed in the macrostructure of all the samples. All the samples exhibited defect-free joints. The results revealed that the finer grain size of 2.43 μm was at 0 °C. The macrostructure of SFSW joints separated into the shoulder-driven zone and pin-driven zone due to the low-temperature difference between the environment and water media and the high heat absorption capacity of the water, which caused a more substantial cooling rate during water-submerged welded joints. The microhardness distribution of all the joints showed typical “W” shape characteristics. The microhardness for all submerged samples was higher than in normal air conditions due to the higher thermal cycling effect in submerged conditions. Improved dynamic recrystallization in the joint welded at 80 °C resulted in the highest tensile strength (~249 MPa) and microhardness (~95 HV).

Correlation Study Between Cooling Load and Temperature Sensitivity Considering the Cumulative Effect of Temperature

To study the correlation between cooling load and air temperature, this paper uses the maximum load comparison method to calculate the cooling load based on the actual load data of the power grid, and uses the temperature correction model to correct the daily maximum temperature, and then establishes a high-order regression model of cooling load and corrected air temperature. The method is applied to the sensitivity analysis of cooling load and air temperature in the Chongqing power grid and sub-regions, and the corresponding change law is obtained, which provides an important reference basis for the production and dispatch, optimal operation, and marketing of the power grid.

The effect Cooling Water Temperature in Air Gap Membrane Distillation for Breaking of Butyric acid – Water Azeotrope

The effect Cooling Water Temperature in Air Gap Membrane Distillation for Breaking of Butyric acid – Water Azeotrope

The Effect of Heating and Cooling Media Temperature on Injection Molding Products Shrinkage

Injection molding is the process of molding products with various shapes and sizes from plastic materials. The problem that often arises is the presence of product defects due to shrinkage. In this regard, the effect of water cooling on product size shrinkage in the injection molding process of making acetabular cups with polypropylene plastic and metal steel mold materials will be investigated through experimental investigations. The test begins with the manufacture of molds and injection machines, then the PP liquid plastic is injected twice into the mold, the first with cooling and the second without cooling. Both products are compared for depreciation by measurement. Shrinkage analysis is done by measuring the height and diameter of the product which is then compared with the size of the mold, so that final conclusions can be drawn. Measurement of shrinkage on the outside of the product is taken from three directions, namely the height of the X-axis product (dx), the outside diameter of the Y-axis product (dy), and the outside diameter of the Z-axis product (hz). For the inside of the product with a hemispherical shape, the shrinkage measurement is calculated by calculating the volume which can then be found the average radius. The results showed that the average shrinkage of the cooling test on the X axis = 1.224 %, on the Y axis = 1.857 %, on the Z axis = 1.83%, and on the radius r = 0.825 %. The average shrinkage of the test without cooling on the X axis = 1,591 %, on the Y axis = 2,32%, on the Z axis = 2,369 %, and on the radius r = 1,267 %.&#x0D; Keywords: Injection Molding, Shrinkage, Heating Cooling Temperature

Investigation of Thermal Adaptation and Development of an Adaptive Model under Various Cooling Temperature Settings for Students’ Activity Rooms in a University Building in Malaysia

The use of an air conditioner (AC) becomes essential, particularly in a hot and humid climate, to provide a comfortable environment for human activities. The setpoint is the agreed temperature that the building will meet, and the use of the lowest setpoint temperature to accelerate the cooling of indoor spaces should be avoided. A comprehensive field study was conducted under various cooling temperature settings in two student activity rooms in a university building in Malaysia, so as to understand respondents’ characteristics and behavior toward AC usage, to estimate the comfort at various indoor temperatures, to develop an adaptive model of thermal comfort in AC spaces, and to compare the comfort temperature with related local and international indoor thermal environmental standards. The findings indicated that water intake and clothing insulation affected personal thermal comfort. Moreover, the mean comfort temperature for respondents was 24.3 °C, which is within an indoor thermal comfort zone of 23–27 °C. The findings suggest that the preference of occupants living in a hot and humid region for lower temperatures means that setting temperatures lower than 24 °C might underestimate the indoor comfort temperature. Additionally, an adaptive relationship can be derived to estimate the indoor comfort temperature from the prevailing outdoor temperature.

Determination of Cooling Rate and Temperature Gradient during Formation of Cathode Spot Craters in a Vacuum Arc

Due to the extreme thermal conditions and short lifetimes, experimental exploration of cathode spots in vacuum arcs is very difficult. The intensive heat in the cathode spot is believed to be generated by ion bombardment and by Joule heating. However, thermal conditions occurring inside the re-melted material in craters created by cathode spots are not accurately known. During the exposure to cathodic arc plasmas, an Al-Cr cathode’s surface was locally melted by successive ignition and extinction of cathode spots. The melted layer, that quickly solidified, was characterized by the formation of several thin layers with a thickness of a few micrometers that were stacked on top of each other. The corresponding solidification patterns displayed cellular and dendritic microstructures. A phase field-based model was used to simulate and determine the thermal process conditions that led to the dendritic structures observed within the re-melted layer. Different combinations of cooling rates and temperature gradients were numerical explored to determine the most probable thermal conditions under which the cathode material re-solidifies. The results showed that the material in the vicinity of the cathode spot crater re-solidified under the condition of a cooling rate of about 3 × 105 K/s and a temperature gradient of about 6 × 107 K/m. These results constitute valuable data for the validation of numerical models dedicated to cathode spot formation.

Temperature and Residential Electricity Demand for Heating and Cooling in G7 Economies: A Method of Moments Panel Quantile Regression Approach

The global energy system is highly vulnerable to climate variability and change. This results in a vast range of impacts on the energy demand sector and production and supply channels. This article aims to estimate the impacts of variables such as heating and cooling temperatures, income, population, and price on residential electricity demand in G7 countries. Methodologically, this study uses the second-generation panel unit root and cointegration approaches (which are robust in the presence of cross-sectional dependence), a panel fixed effects model with Driscoll–Kraay standard errors, and a novel method of moments quantile regression (MM-QR) to determine long-run elasticities. The results suggest that the residential electricity demand of G7 countries is statistically and positively responsive to cold days rather than hot days. This study also presents some policy-relevant issues based on the results.

Controlled Cooling Temperature Prediction of Hot-Rolled Steel Plate Based on Multi-Scale Convolutional Neural Network

Controlled cooling technology is widely used in hot-rolled steel plate production lines. The final cooling temperature directly affects the microstructure and properties of steel plates, but cooling and heat transfer constitutes a nonlinear process, which is difficult to be accurately described using a mathematical model. In order to improve the accuracy of the controlled cooling temperature, a multi-scale convolutional neural network is used to predict the final cooling temperature. Convolution kernels with different sizes are introduced in the layer of a multi-scale convolutional neural network. This structure can simultaneously extract the feature information of different sizes and improve the perceptual power of the network model. The measured steel plate thickness, speed, header flow, and other variables are taken as input. The final cooling temperature is taken as the output and predicted using a multi-scale convolutional neural network. The results show that the multi-scale convolution neural network prediction model has strong generalization and nonlinear fitting ability. Compared with the traditionally structured BP neural network and convolution neural network (CNN), the mean square error (MSE) of the multi-scale convolutional neural network decreased by 24.7% and 12.2%, the mean absolute error (MAE) decreased by 19.6% and 7.97%, and the coefficient of determination (R2) improved by 4.26% and 2.65%, respectively. The final cooling temperature traditional structure by the multi-scale CNN agreed with the actual temperature within ±10% error bands. As the prediction accuracy improved, the multi-scale CNN can be effectively applied to hot-rolled steel plate production.

Spray Cooling Schemes and Temperature Field Analysis of Ultra-High-Temperature Production Wells in Underground Coal Gasification

In underground coal gasification (UCG), it is essential for UCG production to accurately control the temperature of the gas produced at the wellhead of the production well and correctly calculate the variation law of the temperature field in the whole wellbore. UCG wellbore structures use three wellbore sprayed water cooling schemes. These schemes consider the heat exchange mechanism between the wellbore and the formation, the division of the production wellbore into the spray chamber section and the non-spray section, and the established temperature field model of the whole wellbore. The research shows that, due to the large temperature gradient formed in the wellbore heat transfer route under the spray tubing water injection cooling scheme, the temperature of the produced gas drops the most. The annular water injection cooling scheme can protect the cement sheath to a certain extent and is easier to implement; therefore, it is more suitable to use this scheme to cool the production well. It is feasible to control the temperature of the production wellhead by controlling the temperature of the spray chamber. The greater the daily output of produced gas or the thermal conductivity of the tubing, the smaller the temperature change between the bottom hole and the wellhead, and the more the spray water temperature rises.

Predictive model for growth of Clostridium botulinum from spores at temperatures applicable to cooling of cooked ground pork

Cooling deviations and temperature abuse are two main reasons leading to the risk of Clostridium botulinum outgrowth in cooked pork. The aim of this research was to create a model that could be used to estimate C. botulinum growth from spores in cooked pork at temperatures similar to those used to chill cooked pork in processing facilities and food establishments. A cocktail of proteolytic C. botulinum types A and B consisting of five strains per type were used to inoculate pork to a final spore concentration of approximately 2 log CFU/g and cooked to 71 °C to heat shock the spores and kill vegetative microbes. The growth of C. botulinum was established at constant storage temperatures from 10 to 46 °C. C. botulinum growth was also studied under dynamic temperature conditions with cooling set to start at 54.4 °C and end at 4.4 °C or 7.2 °C in monophasic or biphasic cooling profiles, respectively. Growth parameters were estimated using the Baranyi model as a primary model and growth rates were fitted using the modified Ratkowsky secondary model with respect to temperature. The R2 values ranged from 0.7653 to 0.9995 indicating that the Baranyi primary model was well suited to the growth data. The modified Ratkowsky secondary model's R2 was 0.9653 and its root mean square error (RMSE) was 0.0687. All 11 prediction error values computed were within the limit of acceptable prediction zone (−1.0 to 0.5) suggesting a good fit of the model. The predictive model can provide information for the safety of cooked pork exposed to longer chilling times or for customized process schedule development as cooling of larger diameter products presents a processing challenge in the meat process operations.

Experimental Demonstration of the Influence of Cooling Temperature on the Thermal Mode Instability in the YB-Doped Fiber Oscillator

Mode instability (MI) has become a major factor that restricts the brightness enhancement of fiber laser. This paper studies the MI threshold characteristics of the fiber oscillators with refrigerated ytterbium-doped fiber (YDF). In the experiments, two fiber lasers that can operate at low temperature were built. We rigorously tested the MI threshold of the lasers with the YDF placed in two different environments. At room temperature environment, the MI threshold of the oscillator was measured with the temperature of the YDF water cooling plate ranging from 25 °C to 5 °C. When the cooling temperature of the YDF drops from 20 °C to 5 °C, the MI threshold of the laser rises gradually, but the increase is small. In another experiment, the YDF is assembled in a constant temperature test chamber, in which the cooling of the YDF is more efficient. It is found that as the cooling temperature drops, the MI threshold of the laser has an obvious upward trend. In the process of the cooling temperature of the YDF dropped from 20 °C to −10 °C, the MI threshold of the laser was increased from 867 W to above 931 W, an increase of nearly 10%. It is the first detailed experimental demonstration which shows that decreasing the cooling temperature of the gain fiber can indeed increase the MI threshold of the fiber oscillator. This work can clarify the influence of cooling temperature on the laser thermal effect, which is conducive to perfecting the theoretical model of the MI effect.