Room Refrigeration Research Articles

Perancangan Sistem Pendingin dan Tata Udara pada Ruang Mesin produksi di PT. X untuk Menjaga Performa dan Ketahanan Komponen Mesin

Several influencing factors, including temperature, air cleanliness, and humidity levels, are necessary to preserve the performance and durability of engine components against injury. Many mechanical and electrical components of the machine were damaged at Company X because the room's temperature, air quality, and humidity did not comply with the machine's standard operating conditions. If nothing is done to enhance the engine room's air conditioning, the engine will sustain greater damage. The purpose of this research is to design a cooling and air-conditioning system in the production machine space in PT. X to maintain the performance and durability of machine components. The engine compartment is 104 m2. The design of the refrigeration and air conditioning systems includes the calculation of the required capacity, analysis, and the creation of design drawings in the engine compartment. According to the calculation, the required engine room refrigeration capacity unit is 9.36 kW with 1640 l/s. This capacity incorporates the requirement for fresh air, which is 245 l/s. With this capacity, the engine's optimal temperature and oxygen quality can be attained.

Energy Saving Analysis of refrigeration room Group Control Based on Kernel Ridge Regression Algorithm

Generally, the central air conditioners are centralized in a refrigeration room in public buildings. The proportion of energy consumption of the refrigeration room is about 40% of entire building. This paper aims to propose an energy plus and self-designed simulator to reduce the energy consumption of a large electronic factory in Zhuhai City, Guangdong province, China. In this paper, the real data collected from the electronic factory in February and the group control method used in the refrigeration room based on the kernel ridge regression algorithm. The correctness of the kernel ridge regression algorithm was verified with the experimental results. Compared to traditional PID control method, the kernel ridge regression algorithm could dynamically adjust those parameters, such as temperature and frequency to match the high efficiency zone of each device. The overall average COP of the system is increased from 4.17 to 7.04. The electricity of the refrigeration room could save 64 MWh with the cooling load forecast error being below 7% in February. The power consumption is expected to reduce by 8.2% and 562.3 MWh in 2022.

Energy-saving method and performance analysis of chiller plants group control based on Kernel Ridge Regression and Genetic Algorithm

The upgrading of traditional chiller plants to the high-efficiency refrigerator room is conducive to effective utilization and conservation of energy. An energy-saving method of chiller plants group control based on Kernel Ridge Regression and Genetic Algorithm are presented. Combined with machine learning and the classic model of the chiller plants, the multiple nonlinear problems between the system parameters of the chiller plants are solved. A more detailed group control model of chiller plants is established, which is suitable for multiple chillers, variable-speed pumps, and variable-frequency fans. Incorporate the start-up time of the chiller, the difference between the actual cooling capacity and the target cooling capacity into the penalty function, and use the Genetic Algorithm for multi-dimensional optimization to find the best efficiency point of the entire refrigeration room and achieve the goal of energy saving. A comparative analysis of the actual operation of the cold room system of a large electronics factory in Guangdong for three months is carried out. Compared with the traditional PID algorithm, the three-month power saving rate of this group control energy saving method is: 31.34%, 14.33%, 19.22%.

Design and Development of Performance Rating Apparatus for Cold Room Refrigeration Unit Using Cooling-Load Balance Method

Refrigeration systems are composed of many components working together, and their refrigerating capacity depends upon these components constituting the refrigeration system. The design of the refrigeration system does not only consider cooling loads from products but also the operating conditions that change from time to time, especially the ambient temperatures due to global warming and climate change. Therefore, this work aims to develop the apparatus for performance rating of the cold room’s refrigeration unit according to the ASHRAE standard test methods as well as the Eurovent certification programs. The principle of enthalpy change is used to determine the system performance, in general. In this work, the cooling-load balanced method is proposed, which shows a good refrigeration capacity estimation by balancing the cooling load with refrigeration capacity. In addition, the use of an ultrasonic flow meter for refrigerant flow rate measurement is also discussed for additional validation in future works.

Stability of Hydrocortisone Sodium Succinate in Intensive Care Units: Focus on Practical Points

Background: Although single daily 24 hours preparation of hydrocortisone solution infusion is widely used in intensive care clinical practice, most manufacturers limit its infusion time to only four hours. The data on efficacy of this practice are scarce. Objective: To determine the physical and chemical stability of hydrocortisone solution used in intensive care units (ICU). Materials and Methods: Powder form of 100 mg hydrocortisone was reconstituted first with sterile water for injection (SWI) and then added to normal saline solution (NSS) to obtain 1 and 2 mg/mL solutions, or first reconstituted with NSS then added to bag of NSS to obtain 1 mg/mL solution. The solutions were then stored in three different conditions, refrigerator (4±2℃), ICU (25±3℃), and hospital room (30±2℃) temperatures for 48 hours. The physical and chemical stabilities were assessed at an initial time, 4, 8, 12, 24, and 48 hours. Results: Hydrocortisone reconstituted in SWI showed an acceptable labeled amount range (100.28±3.83%), similar to reconstitution in NSS (96.05±1.00%). Hydrocortisone solutions of 1 and 2 mg/mL stored at 4±2℃, 25±3℃, and 30±2℃ showed similar percent label amount, and the statistical tests were not significantly different among the three ranges of temperatures (p>0.05). Conclusion: Hydrocortisone reconstituted using SWI followed by NSS to obtain final concentrations of 1 to 2 mg/mL or using only NSS to obtain a final concentration of 1 mg/mL, provided an acceptable range of % hydrocortisone remaining up to 48 hours when stored at 4±2℃, 25±3℃, and 30±2℃. Keywords: Hydrocortisone; Intensive care units; Normal saline solution; Stability; Sterile water for injection

Qualitative and Nutraceutical Characteristics after Storage of New Pear Selections in Emilia-Romagna Region

The Emilia-Romagna region is excellent in European pear production. CREA Centro di Ricerca Olivicoltura, Frutticoltura e Agrumicoltura leads a breeding project co-founded by New Plant (a consortium of three growers’associations Apofruit, Apoconerpo, and Orogel Fresco) whose main objective is to improve fruit quality and nutraceutical parameters. The purpose of this study is to describe the qualitative characteristics of some new genotypes obtained by this breeding activity after cold storage, in comparison with the main cultivated varieties, ‘Abbé Fétel’, ‘William’s B.C’ and ‘Doyenne du Comice’. In 2013, 2014, and 2015, fruit samples, stored in a normal refrigeration room and after 100 dd, reaching the consumption ripening (2.5–3 kg/0.5 cm2), were analyzed to quantify the qualitative parameters: average weight, caliber, titratable acidity, soluble solids contents, skin color and overcolor, sugar and organic acids content, the antioxidant capacity, the total polyphenols, and ascorbic acid content. The results showed that the selection ‘CREA 171’, with red skin and yellow-cream flesh, outstood for the high antioxidant capacity due to the high content of polyphenols and ascorbic acid.

Pengaruh Variasi Lilitan Pipa Kapiler pada Line Suction terhadap Laju Pendinginan dan Capaian Suhu Optimal Ruangan Prototype Trainer Lemari Pendingin

This study aims to find the effect of variations in the capillary tube winding on the suction line on achieving optimal temperature and room cooling rate. This study uses three variations: the capillary tube without being wrapped around the suction line, the capillary tube wrapped in half on the suction line, and the capillary tube fully wound on the suction line. Specifically, the purpose of this study was to determine the effect of variations in the capillary tube wrapped around the suction line, which led to efforts to maintain the performance of the refrigerator trainer prototype. The method used in this study uses an experimental method where the data collection process is carried out through observation and documentation. The data analysis technique used in this study uses quantitative descriptive research techniques where the research data will be tabulated and displayed in the form of tables and graphs, and data analysis is carried out to find out how much influence the achievement of the optimal room temperature and the cooling rate of the prototype trainer refrigerator room itself. From the research that has been carried out, it is obtained that the highest optimal room temperature achievement occurs in the variation of the capillary tube fully wound on the suction line, where there is an increase in the optimal room temperature achievement of 16.17% when compared to the room cooling rate using standard variations or without being wrapped. And the result in the form of the highest room cooling rate is the variation of the capillary pipe fully wound on the suction line.

Coping with Tissue Sampling in Suboptimal Conditions: Comparison of Different Tissue Preservation Methods for Histological and Molecular Analysis.

Simple SummarySpecimen collection and preservation can be challenging, especially when suboptimal conditions occur. A relevant amount of time could be required from sampling to the tissue analysis, and therefore a high-quality conservation technique is vitally important for diagnostic purposes. The aim of this study was the identification of a reliable and economic method for tissue preservation to be used in complex “in-field” situations, suitable for both histological and molecular analysis. Punch biopsies were collected from six cattle livers. Comparison among methods of preservation using RNAlater, silica beads, or under-vacuum was carried out using different times and temperatures. Three days were assumed as a maximum time interval from sampling to laboratory and 4 °C and 24 °C chosen as references for refrigeration temperature and room temperature, respectively. Histological and biomolecular analyses were performed. RNAlater and silica beads poorly preserved the histological parameters evaluated; conversely, vacuum-sealed samples showed a good grade of preservation for 48 h. DNA quality was acceptable for each sample. RNA integrity showed promising results for samples preserved with silica beads.A high quality of samples is crucial for the success of the analysis and diagnostic purposes, and therefore the right method of conservation is vitally important for an optimal preservation of tissues. Indeed, the time to deliver the sample to the laboratory could be remarkably long, especially under suboptimal conditions, and the use of specific fixatives or cold storage may not be possible. Moreover, the portability and cost of storage equipment, their toxicity, and their ease of use play a central role when choosing the correct preservation method. The aim of this study was the identification of a reliable and economic method for tissue preservation, to be used in “in-field” sampling, suitable for both histological and molecular analysis. Punch biopsies were collected from six cattle livers. Comparisons among methods of preservation using RNAlater, silica beads, and under-vacuum was carried out. These methods were tested through considering different times and temperatures, assuming three days as a maximum time interval from sampling to laboratory and choosing 4 °C and 24 °C as references for refrigeration temperature and room temperature, respectively. Histologically, the integrity of nucleus, cytoplasm, preservation of liver structure, and easiness of recognition of inflammatory infiltrate were evaluated. The integrity of the extracted DNA and RNA was evaluated through PCR and by means of an automated electrophoresis station, respectively. RNAlater and silica beads poorly preserved the histological parameters evaluated, independently from the temperature. Conversely, the vacuum-sealed samples showed a good grade of preservation until 48 h. DNA quality was acceptable for each sample. RNA integrity showed promising results only for samples preserved with silica beads.

Paletero Man by Lucky Diaz

Reviewed by: Paletero Man by Lucky Diaz Elizabeth Bush Diaz, Lucky Paletero Man; illus. by Micah Player. HarperCollins, 2021 [32p] Trade ed. ISBN 9780063014442 $17.99 E-book ed. ISBN 9780063089556 $12.99 Reviewed from digital galleys R 3-6 yrs It’s a sizzling day, and our Angeleno narrator is on a mission to track down the paleta vendor and some icy refreshment. There’s no time to stop for conversation or treats from his favorite haunts—Tio Ernesto’s tamale cart, Ms. Lee’s Korean BBQ stand, Frank’s bike shop—as he rushes toward the park. As anticipated, there’s José, calling out, “Paletas for one! Paletas for all!” and he even has the piña flavor our little guy craves. Gadzooks! The narrator’s pockets are empty and the mission looks doomed, until Ernesto, Mr. Lee, and Frank show up with the coins he dropped along the way when he was in too great a hurry to stop and chat; José then rewards the good deed with paletas all around. Diaz’s story in verse, with its chantable refrain and kid-sized dollop of tension, is a paean to Eighth Street Los Angeles food culture, affectionately described in a closing note. Player’s energetic Photoshop illustrations sport the distinctive technicolor paleta palette that’s sunshine itself. Whether it’s sourced from a street cart, a taqueria freezer, or the library’s back room refrigerator, we all know what the storytime treat will be. Copyright © 2021 The Board of Trustees of the University of Illinois

Case report: Thrombosis in children

Objective: We examined the effects of passenger air transport by regular airplanes for air transportation on blood for transfusion. Materials and methods: Irradiated red blood cell (RBC) solutions were transported by regular passenger airplanes which and were static in the cabin during the flight. Blood samples were evaluated visually and biochemically before and after transport. Hemolysis of the transported samples was compared to that of the non-transported ones. The vibration in the airplanes was also measured using a vibration data logger. Results: There was no significant hemolysis of RBCs during airplane transport. The vibration in the airplane was lower than that in automobiles. The temperature in the active transport refrigerator (ATR) room was maintained at 2−6°C. There was no significant hemolysis of RBCs during the two transport routes. Conclusion: Temperature-controlled air transport of blood transport in the ATR 700 airplane maintained a the blood at a good quality that rendered blood it fit for blood transfusion.

Effects of passenger airplane transport on blood

Objective: We examined the effects of passenger air transport by regular airplanes for air transportation on blood for transfusion. Materials and methods: Irradiated red blood cell (RBC) solutions were transported by regular passenger airplanes which and were static in the cabin during the flight. Blood samples were evaluated visually and biochemically before and after transport. Hemolysis of the transported samples was compared to that of the non-transported ones. The vibration in the airplanes was also measured using a vibration data logger. Results: There was no significant hemolysis of RBCs during airplane transport. The vibration in the airplane was lower than that in automobiles. The temperature in the active transport refrigerator (ATR) room was maintained at 2−6°C. There was no significant hemolysis of RBCs during the two transport routes. Conclusion: Temperature-controlled air transport of blood transport in the ATR 700 airplane maintained a the blood at a good quality that rendered blood it fit for blood transfusion.

Analysis of Hygrothermal Microclimatic (HTM) Parameters in Specific Food Storage Environments in Slovakia.

The quality of work environment, temperature changes and humidity must be controlled in every production process and in the locations where employees are present. The aim of this paper is to objectively assess the exposure of employees to microclimatic factors of the workplace environment: the warehouse, changing rooms, office and cold room refrigerator. Data were obtained in real working conditions. The heat stress due to cold and heat exposure in the individual locations was evaluated using the WBGT (wet bulb globe temperature) indicator. The parameters of the hygrothermal microclimate (HTM) were objectified by a QUES Temp 44/46 T spherical thermometer. The measurements were performed both in cold and hot periods of the year. The measurements confirmed standard temperatures for individual types of interiors in the winter period, but in the summer period there was a variability of results, leading to the thermal discomfort of employees. The assessment of the WBGT index revealed that nearly 80% of employees are susceptible to hypothermia as a result of thermal stress conditions. It was proven that the temperatures measured by a spherical thermometer in the hottest room were 8.62% higher than the calculated operating temperature, while the difference in the cold room refrigerator was only 1.28% higher.

Frost detection method on evaporator in vapour compression systems

To preserve food nutrients, texture, and taste, as well as to prevent its putrefaction, food is frozen and kept at around −20 °C. Refrigerators and freezers are highly energy demand systems which can suffer a considerable decrease in operational efficiency due to frost growth on the evaporator. Defrost processes are launched periodically to avoid the frost built-up, consuming a relevant part of the total energy demand. To control the defrost launching and to improve the energy performance of the refrigeration system an accurate measurement of the frost level is required. Many frost detecting methods are expensive, not feasible due to their size, or simply they cannot measure the frost stacking precisely enough to swerve mal-defrost phenomena. This study provides an accurate parameter to indirectly estimate the frost layer built-up on the evaporator. The new parameter called thermal variation easiness (TVE) was experimentally tested and validated by comparison with another frost leveling method, ΔT method, on a walk-in freezer unit. Then the TVE was successfully tested on a multi-cold room refrigeration system, proving its applicability on both walk-in freezers run by remote condensing units and multiple cold rooms fed by a rack of compressors. The novelty of this parameter lays on its capacity to work on refrigeration facilities which are used to feed several walk-in fridges and refrigerated displays in big installations, such as supermarkets.

Minimizing the thermal bridge through the columns in a refrigeration room

Thermal bridges are weakly insulated areas in the envelope of a building that can significantly increase the energy load due to heat dissipation. To improve energy efficiency, a thermal bridge model is established to simulate heat transfer through the column in a refrigeration room. The accuracy of the numerical simulation program is verified by experimental data. A heat preservation method for the column that minimizes the cooling loss is analyzed. The results show that the thermal bridging is mainly due to the steel bar in the column, because the share of the cooling loss attributed to the steel bars is 42.02–55.87%. Moreover, applying heat insulation on the column can provide more energy savings in low-temperature rooms than in high-temperature ones. The most economical thermal insulation method as a function of the height and thickness of the insulation layer is therefore proposed for the low-temperature column. By the optimum method, the amount of heat flux through the whole column section, which includes both reinforced and non-reinforced areas, decreases by 37.34%, and the total cooling loss decreases from 30.23 to 13.66 W, representing a 54.81% reduction. Therefore, a reduction in the cooling loss from thermal bridging is achieved for a low-temperature refrigeration room.

A model for predicting air permeation between temperature-fluctuated refrigerated room and ambience through magnetic seal

The air permeation caused by the pressure difference at both sides of the magnetic seal accounts for a significant part of energy loss in a refrigerated room. The purpose of this study is to model the air permeation rate. Based on momentum equations of air flow along the permeation paths, the air permeation rate is deduced as a function of the average height of permeation paths and the flow factor. The average height is obtained by a resultant force of magnetic attraction and pressure difference under the assumption of parabolic asperity profile in the permeation paths; and the flow factor is calculated by semi-empirical correlations based on the average height of the permeation paths. An experiment is designed to validate the model, and the results show that the predicted air permeation rate can describe 98% of the experimental data within a deviation of ± 15% and the mean deviation is 5.6%.

Unjuk kerja kulkas termoelektrik dengan rangkaian seri dan paralel pada beban air 1500 ml

Along with the increase of human mobility, the portable refrigerator becomes very important because it can be used to store goods or drinks to be durable or cooler. Therefore, a refrigerator using thermoelectric is an option. Thermoelectric fridge besides easy to carry anywhere is also easy maintenance, durable, more compact, lightweight, no heavy rotating components, no use of freon and small power. Refrigerator research with thermoelectric has been done with series and parallel electric circuits to know the effect of the circuit difference to the performance of refrigerators. This study uses a mini fridge with an overall dimension of 40.8 cm x 32.6 cm x53.8 cm and with 2 thermoelectric modules TEC1-12706 model. The electrical power used for each circuit is about 12 W. The data retrieval in the test uses DAQ MX 9714 NI data logger which is connected to the PC using LabView program. The results show that the test research with a water load of 1500 ml results in the temperature of the refrigerator room of about 22.54oC for the series and 23.10oC for the parallel. While the value of COP obtained with the series circuit is 0.45 and with the parallel circuit is 0.4. There is no effect of the form of the circuit on the performance of the refrigerator.

Identifying and Assessing the Process Risks of Ammonia Refrigeration Room by Using the HAZOP Technique to Provide Solutions to Control and Reduce Accidents in the Food Industry

Identifying and Assessing the Process Risks of Ammonia Refrigeration Room by Using the HAZOP Technique to Provide Solutions to Control and Reduce Accidents in the Food Industry

Compatibility of fosfomycin with different commercial peritoneal dialysis solutions

For treatment of peritoneal dialysis-related peritonitis, intraperitoneal administration of antibiotics remains the preferable route. For home-based therapy, patients are commonly supplied with peritoneal dialysis fluids already containing antimicrobial agents. The present study set out to investigate the compatibility of fosfomycin with different peritoneal dialysis fluids, namely, Extraneal®, Nutrineal®, Physioneal® 1.36% and Physioneal® 2.27%, under varying storage conditions. The peritoneal dialysis fluid bags including 4 g fosfomycin were stored over 14 days at refrigeration temperature (6°C) and room temperature (25°C) and over 24 h at body temperature (37°C). Drug concentrations over time were determined by using high-performance liquid chromatography coupled to a mass spectrometer. In addition, drug activity was assessed by a disk diffusion method, diluent stability by visual inspection and drug adsorption by comparison of the measured and calculated concentrations. Blank peritoneal dialysis fluids and deionized water were used as comparator solutions. Fosfomycin was stable in all peritoneal dialysis fluids and at each storage condition investigated over the whole study period. The remaining drug concentrations ranged between 94% and 104% of the respective initial concentrations. No significant drug adsorption was observed for any peritoneal dialysis fluid at any storage condition. No relevant reduction of antimicrobial activity was observed. Fosfomycin is compatible with Extraneal®, Nutrineal® and Physioneal® for up to two weeks at refrigeration or room temperature and may be used for home-based therapy. No dose adjustment is needed due to adsorption or degradation.

Seeds Characteristics of Gelam (Meulaleca leucadendra): Seed Maturity, Morphology, Germination and Storability

Gelam (Meulaleuca leucadendra (L.) L.) is a potential species for construction timbers adapted to degraded swamp forest. Cultivation of this species is still limited and needs supporting of information of seed procurement technology, such as seed maturity, germination technique and storability. The present paper deals with assessing of seed maturity, morphology, germination and storability of the species. The seeds were collected from three natural populations, i.e. Landasan Ulin, Gasing, and Jabiren, and tested in a laboratory. The results showed that seed maturity can be identified from source of fruit/stalk. Seeds from the second and third fruit stalks resulted the best germination capacity,i.e 984 seedlings -0.1 g and 809 seedlings -0.1 g , repectively. Fruit morphology, seed germination, and storability were significantly different among populations. Fruit from Gasing with length of 3.81 mm, diameter of 3.79 mm and weight of 0.037 g had higher sizes than fruits from Landasan Ulin and Jabiren. The best seed germination of the three seedlots was resulted from top paper method with 12 hours lighting period. In the nursery practices, the mixed media of sand and rice husk charcoal (1:1 v/v) gave the best result of germination. The best storage of seeds was refrigerator room wraped by impermeable plastic bag. Seeds from Jabiren provided the best germination and storability that gave a germination capacity of 925seedlings -0.1g and 731 seedlings -0.1 g before and after storage for one year, respectively.

Bioactive components, antioxidative properties and inhibition of Fe2+-induced lipid peroxidation of mango peel as affected by the storage of mango fruit

This study sought to evaluate the bioactive components (total phenolics, vitamin C and flavonoid), antioxidant properties (FRAP, and hydroxyl, DPPH and ABTS radical scavenging abilities) and inhibition of Fe2+-induced lipid peroxidation of the peel of mango fruit stored at refrigeration temperature and room temperature. The peel of mango fruit stored at room temperature had significantly (P ≤ 0.05) higher contents of total phenolic (13.61 mg GAE/g), vitamin C (12.98 mg AAE/g), total flavonoid (4.49 mg QE/g) and non-flavonoid (9.12 mg Qe/g) than the peel of freshly harvested mango fruit and the peel of mango fruit stored at refrigeration temperature. In consonance with the bioactive components, the peel of mango fruit stored at room temperature had a higher FRAP, and hydroxyl, DPPH and ABTS radical scavenging abilities than the others. The peel of mango fruit stored at room temperature showed stronger inhibition of Fe2+ induced lipid peroxidation by exhibiting the least IC50 (1.44 mg/ml in brain), (1.43 mg/ml in pancreas) and (1.88 mg/ml in kidney). Thus freshly harvested, matured, edible and just ripe mango fruit (Sheri Mango) could be stored at room temperature and be consumed with the peel.