scholarly journals DESIGN, CONSTRUCTION AND TESTING OF A COLD STORE WITH WATER-COOLED CHILLER

2022 ◽  
Vol 52 (1) ◽  
pp. 21-26
Author(s):  
Serap Akdemir
Keyword(s):  
Standard Deviation ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Heat Load ◽  
Cooling System ◽  
Descriptive Statistics ◽  
Air Velocity ◽  
Cold Store ◽  
Different Levels ◽  
Design Construction

Objective of this research was to design, construction and test of a cold store with chiller unit. Dimensions of the cold store were 5x4x3m. Heat load was calculated and capacity of cooling system was determined. Ambient temperature was set 2oC and relative humidity 90% for cold store testing. Ambient temperature, relative humidity and air velocity were measured for 3 different levels and 12 points for each level in the cold store. Total heat load and capacity of cooling system were calculated 5222 kcal/h. and 6.07 kW respectively.  The descriptive statistics  were calculated for the ambient temperature;  mean, 2.82oC, standard deviation 0.02oC and CV(%) 0.56, and  for the relative humidity; mean 88.01%, standard deviation 0.61 (%) and CV(%)  0.70 and for the air velocity mean 0.37m/s, standard deviation 0.22 m/s, CV 33.45 %. Even the air velocity CV was high, the ambient temperature and relative humidity variations were evaluated very good.

scholarly journals CFD MODELLING AND VALIDATION OF AMBIENT FACTORS IN EVAPORATIVE COLD STORE FOR PEACH STORAGE

2022 ◽  
Vol 52 (1) ◽  
pp. 55-60
Author(s):  
Serap Akdemir
Keyword(s):  
Relative Humidity ◽  
Ambient Temperature ◽  
Relative Error ◽  
Storage Temperature ◽  
Cooling System ◽  
Cfd Modelling ◽  
Acceptable Error ◽  
Cfd Models ◽  
Evaporative Cooling System ◽  
Cold Store

Spatial variation of temperature and relative humidity were estimated with Computational Fluid Dynamics (CFD) at top, middle and base levels for peach storage at +1oC and 90% relative humidity and verified with measured data in a cold store with evaporative cooling system. Storage temperature was +1oC and relative humidity 90% for peach storage. Ansys Fluent Software was used for CFD modelling. CFD models were validated with sensors measurements. Results were evaluated by using descriptive statistics, relative error and variance analyses. Mean difference between the model and measurements was calculated as 0.51oC for ambient temperature and as 3.47 % for relative humidity. Relative error of the CFD model was calculated as 9.77 for the ambient temperature and 1.29 for relative humidity for peach storage. The developed CFD models estimated the ambient factors with an acceptable error in the evaporative cold store for peach storage.

scholarly journals A Numerical Analysis of the Cooling Performance of a Hybrid Personal Cooling System (HPCS): Effects of Ambient Temperature and Relative Humidity

2020 ◽  
Vol 17 (14) ◽  
pp. 4995
Author(s):  
Pengjun Xu ◽  
Zhanxiao Kang ◽  
Faming Wang ◽  
Udayraj Udayraj
Keyword(s):  
Numerical Analysis ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Thermal Performance ◽  
Environmental Temperature ◽  
Cooling System ◽  
Cooling Performance ◽  
Hot Environment ◽  
Four Levels ◽  
Personal Cooling

Hybrid personal cooling systems (HPCS) incorporated with ventilation fans and phase change materials (PCMs) have shown its superior capability for mitigating workers’ heat strain while performing heavy labor work in hot environments. In a previous study, the effects of thermal resistance of insulation pads, and latent heat and melting temperature of PCMs on the HPCS’s thermal performance have been investigated. In addition to the aforementioned factors, environmental conditions, i.e., ambient temperature and relative humidity, also significantly affect the thermal performance of the HPCS. In this paper, a numerical parametric study was performed to investigate the effects of the environmental temperature and relative humidity (RH) on the thermal management of the HPCS. Five levels of air temperature under RH = 50% (i.e., 32, 34, 36, 38 and 40 °C) and four levels of environmental RH at two ambient temperatures of 36 and 40 °C were selected (i.e., RH = 30, 50, 70 and 90%) for the numerical analysis. Results show that high environmental temperatures could accelerate the PCM melting process and thereby weaken the cooling performance of HPCS. In the moderately hot environment (36 °C), HPCS presented good cooling performance with the maximum core temperature at around 37.5 °C during excise when the ambient RH ≤ 70%, whereas good cooling performance could be only seen under RH ≤ 50% in the extremely hot environment (40 °C). Thus, it may be concluded that the maximum environmental RH under which the HPCS exhibiting good cooling performance decreases with an increase in the environmental temperature.

scholarly journals A Local Air Velocity Measurement Method for Estimating Infiltration Heat Load through Doorway of the Cold Store

2017 ◽  
Vol 105 ◽  
pp. 3275-3281 ◽  
Author(s):  
Shen Tian ◽  
Yuping Gao ◽  
Shuangquan Shao ◽  
Hongbo Xu ◽  
Changqing Tian
Keyword(s):  
Velocity Measurement ◽  
Heat Load ◽  
Measurement Method ◽  
Air Velocity ◽  
Cold Store

Temperature Changes of Fabrics for the Drop Test with Different Volumes of Water

2013 ◽  
Vol 339 ◽  
pp. 691-694
Author(s):  
Chun Hong Zhu ◽  
Masayuki Takatera
Keyword(s):  
Relative Humidity ◽  
Ambient Temperature ◽  
Water Transport ◽  
Cotton Fabric ◽  
Polyester Fabric ◽  
Drop Test ◽  
Air Velocity ◽  
Polyester Fabrics ◽  
Temperature Changes

In this paper, the drop test on cotton and polyester fabrics were conducted when 0.5ml and 2ml water dropped on fabric at an ambient temperature of 20 ± 1 °C, relative humidity levels of 65 ± 2%, and an air velocity of 0 to 0.2m/s. The temperature changes on these fabrics were measured. The results showed that it cost much time of 2ml water than 0.5ml water dropped on two kinds of fabrics. As cotton fabric, when 0.5ml water dropped on fabric, the temperature at point 1 changes little than polyester fabric, this isbecause cotton absorbed much water than polyester, there is little water transport to the distance of 6cm. Either 0.5ml or 2ml water dropped on fabric, the time for polyester fabric is shorter than that of cotton fabric, this can be seen the property of drying-fast of polyester fabric.

scholarly journals Pengaruh Ketinggian Tempat Terhadap Respon Termoregulasi Kambing Peranakan Etawah (PE)

2016 ◽  
Vol 6 (1) ◽  
pp. 52-62
Author(s):  
Diana ◽  
Bagus Priyo Purwanto ◽  
Afton Atabany
Keyword(s):  
Heart Rate ◽  
Regression Analysis ◽  
Relative Humidity ◽  
Environmental Factors ◽  
Ambient Temperature ◽  
Respiration Rate ◽  
Rectal Temperature ◽  
T Test ◽  
Thermoregulatory Response ◽  
Air Velocity

Etawah grade does were kept in different environment. Current research was conducted to compare the thermoregulatory response of Etawah grade goat which were kept at 200, 400 and 600 m asl. Measured environmental factors were temperature (Ta), relative humidity (Rh), and air velocity (Va) were measured for 12 hours from 06.00 am to 06.00 pm. Thermoregulatory response included rectal temperature (Tr), respiration rate (Rr) and heart rate (Hr) were measured every day at 6 am, 12 am and 6 pm. Data obtained were analyzed statistically using independent two-sample T-Test and regression analysis. The results showed different altitude 200, 400 and 600 m asl significantly affected (P<0.05) ambient temperature, which were average 30,16±2,88; 27,73±2,45 and 26,63±2,91; respectively. Otherwise, different altitude did not affect humidity and air velocity. Altitude significantly affected (P<0.05) rectal temperature and heart rate, but did not affect respiration rate. Etawah grade goat were comfortable to kept in 400 m asl.

CATFISH DRYING (Clarias Batraclus) USING ‘TEKO BERSAYAP’ SOLAR DRYER

2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Time ◽  
Ambient Relative Humidity ◽  
Solar Dryer

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.

Karakteristik aliran dua fase pada saluran ekspansi tiba-tiba

2018 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Latif Ngudi Wibawanto ◽  
Budi Santoso ◽  
Wibawa Endra Juwana
Keyword(s):  
Standard Deviation ◽  
Flow Pattern ◽  
Flow Characteristic ◽  
Homogeneous Model ◽  
Flow Equation ◽  
Pressure Recovery ◽  
Sudden Expansion ◽  
Air Velocity ◽  
Model Flow ◽  
Two Phases

This research was conducted to find out the flow characteristic of two phases through the channel with sudden expansion in the form of change of flow pattern and pressure recovery. The test was carried out with variation of superficial velocity of water 0.2-1.3 m / s and superficial air velocity of 0.2-1.9 m / s resulting in pattern of three flow patterns ie bubble, plug, and slug. The expansion channel resulted in some changes to the flow pattern that originally plugs in the upstream channel into bubble in the downstream channel and the slug becomes plug. Pressure recovery experimental results compared with the homogeneous model flow equation and Wadle correlation, both correlations have predictions with standard deviation values of 0.32 and 0.43.

scholarly journals A novel mouse model of heatstroke accounting for ambient temperature and relative humidity

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Keisuke Suzuki ◽  
Hirokazu Ohtaki ◽  
Motoyasu Nakamura ◽  
Hiroki Yamaga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Organ Damage ◽  
Core Body ◽  
The Impact ◽  
Treatment Water

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.

Sign in / Sign up

Export Citation Format

Share Document