scholarly journals EFFECTIVENESS OF SOLAR THERMOELECTRIC COOLER FOR FISH PRESERVATION: EXPERIMENTAL STUDY ON QUALITY CHARACTERISTICS OF Pangasius bocourti FISH FILLETS DURING STORAGE

2021 ◽  
Vol 9 (5) ◽  
pp. 618-629
Author(s):  
Olipriya Biswas ◽  
◽  
Palani Kandasamy ◽  
Goutam Mandal ◽  
Debasis Panda ◽  
...  
Keyword(s):  
Cooling System ◽  
Thiobarbituric Acid ◽  
Cooling Capacity ◽  
Quality Parameters ◽  
Coefficient Of Performance ◽  
Plate Count ◽  
Thermoelectric Cooler ◽  
Water Binding ◽  
Fish Fillets ◽  
Pangasius Bocourti

Preservation of fish products is a big issue where inconsistent electricity supply. In the current study, a solar thermoelectric cooler (STC) was fabricated by exploiting the solar energy and its cooling potential for fish preservation was evaluated. The STC consists of a photovoltaic (PV) panel, battery, PV charge controller, thermoelectric cooling system, and cooler box. The temperature of the STC decreased to 7.4ºC within 90 minutes and then reached 5±0.2ºC in 150 min. The cooling capacity and coefficient of performance of the STC were 23.8 W and 0.44, respectively, at an input electric current of 3.5 A. The Pangasius bocourti fish fillets were stored in the STC for 10 days and tested its quality at 2 days intervals. On day 10, thiobarbituric acid, peroxide, pH, water binding ability, total plate count values were 1.65mg MDA/kg, 5.04 mEqO2/kg, 7.16, 26.18%, and 4.26 log CFU/g, respectively. A significant reduction in hardness, springiness, and chewiness values was observed, whereas no cohesiveness changes. The color values L* and a* decreased significantly, whereas b* and ΔE increased. The sensory attributes were found in the range of 5.2-6.0 on the 10th day. As the quality parameters showing an acceptable level, STC could be an alternate green option for fish preservation.

scholarly journals Melanosis and quality attributes of chill stored farm raised whiteleg shrimp (Litopenaeus vannamei)

2017 ◽  
Vol 9 (1) ◽  
pp. 626-631 ◽  
Author(s):  
S. R. Senapati ◽  
G. Praveen Kumar ◽  
Chongtham Baru Singh ◽  
K. A. Martin Xavier ◽  
M. K. Chouksey ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
Bacterial Load ◽  
Black Spot ◽  
Thiobarbituric Acid ◽  
Quality Parameters ◽  
Plate Count ◽  
Thiobarbituric Acid Reactive Substances ◽  
Chilled Storage ◽  
Total Plate Count ◽  
Whiteleg Shrimp

Loss of market value of shrimp is mainly due to the formation of black spot called melanosis. A study was conducted for 14 days to determine the extent of melanosis and quality changes during that period of freshly har-vested whiteleg shrimp (Litopenaeus vannamei) under chilled storage (2℃). Among quality parameters, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBAR-S), were varied from 13.17 mg % to 44.50 mg % and 0.04to 2.57 mg malondehaldehyde/kg of fat respectively whereas melanosis score and metric chroma (C) exhibited significant increases during chilled storage (P<0.05). There was a slight increase in moisture, crude fat and pH from 73.96 % to 74.57 %, 1.05 % to 1.14 % and 6.52 to 7.60 respectively at 14th day of storage. Loss of protein from 22.51 % to 21.28 % may be due to decrease in available amino acids during chilled storage and total plate count (TPC) showed gradual increase of bacterial load up to 1.73*107 log CFU/g at the end of chilled storage. The sensory analysis by panellists indicated, the acceptability of white leg shrimp was up to 6 days in chilled condition and formation of black spot is one of the major parameter for rejection by the panellists.

Optimized Refrigerant Flow Rate and Dimensions of the Ejector Employed in a Modified Ejector Vapor Compression System

2020 ◽  
Vol 28 (04) ◽  
pp. 2050038
Author(s):  
Dishant Sharma ◽  
Gulshan Sachdeva ◽  
Dinesh Kumar Saini
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Evaporator Temperature ◽  
Proposed Model ◽  
Condenser Temperature ◽  
Vapor Compression System ◽  
Vapor Compression Cooling

This paper presents the analysis of a modified vapor compression cooling system which uses an ejector as an expansion device. Expanding refrigerant in an ejector enhances the refrigeration effect and reduces compressor work. Therefore, it yields a better coefficient of performance. Thermodynamic analysis of a constant area ejector model has been done to obtain primary dimensions of the ejector for given condenser and evaporator temperature and cooling capacity. The proposed model has been used to design the ejector for three refrigerants; R134a, R152a and R1234yf. The refrigerant flow rate and the diameters at various sections of the ejector have been obtained by doing numerical modeling in Engineering Equation Solver (EES). Refrigerant R1234yf demanded the highest diameter requirements at a fixed 5∘C evaporator temperature and 40∘C condenser temperature for a given range of cooling load. Both primary and secondary refrigerants flow rates are higher for R1234yf followed by R134a and then R152a.

scholarly journals Study and Analysis by Numerical Simulation of a Solar Continuous Adsorption Chiller

2015 ◽  
Vol 773-774 ◽  
pp. 605-609
Author(s):  
Rabah Gomri ◽  
Billel Mebarki
Keyword(s):  
Solar Energy ◽  
Cooling System ◽  
Recovery Process ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Solar Collectors ◽  
Adsorption Refrigeration ◽  
Continuous Adsorption ◽  
Adsorption Cooling System ◽  
Mass Recovery

Environment and energy problems over the world have motivated researchers to develop energy systems more sustainable, having as one of the possible alternative the use of solar energy as source for cooling systems. Adsorption refrigeration systems are regarded as environmentally friendly alternatives to conventional vapour compression refrigeration systems, since they can use refrigerants that do not contribute to ozone layer depletion and global warming. In this paper a performance comparison between a solar continuous adsorption cooling system without mass recovery process and solar continuous adsorption cooling system with mass recovery process is carried out. Silica-Gel as adsorbent and water as refrigerant are selected. The results show that the adsorption refrigeration machine driven by solar energy can operate effectively during four months and is able to produce cold continuously along the 24 hours of the day. The importance of the mass recovery is proved in this study by increasing the coefficient of performance and the cooling capacity produced. For the same cooling capacity produced, the required number of solar collectors with mass recovery system is lower than the required number of solar collectors in the case of the refrigeration unit without mass recovery. For the same cooling capacity the system with mass recovery process allowed lower generation temperature.

scholarly journals An experimental investigation on the performance of a thermoelectric dehumidification system

2018 ◽  
Vol 12 (4) ◽  
pp. 4117-4126
Author(s):  
P. Rakkwamsuk ◽  
P. Paromupatham ◽  
K. Sathapornprasath ◽  
C. Lertsatitthanakorn ◽  
S. Soponronnarit
Keyword(s):  
Heat Sink ◽  
Cooling System ◽  
Test Chamber ◽  
Cooling Water ◽  
Suitable Condition ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Air Cooling System ◽  
Te Modules

A thermoelectric (TE) air-cooling system for dehumidifying indoor air in a building was investigated. The system was composed of 4 TE modules. The cold sides of the TE modules were fixed to an aluminum heat sink to remove moisture in the air of a test chamber of 1 m3 volume, while a heat sink with circulating cooling water at the hot sides of the TE modules was used for heat release. The effects of input electric current to the TE modules and air flow rate through the heat sink were experimentally determined. The system’s performance was evaluated using dehumidification effectiveness and coefficient of performance (COP). A suitable condition occurred at 18.5 A of current flow and 240 W of power being supplied to the TE modules with a corresponding cooling capacity of 149.5 W, which gave a dehumidification effectiveness of 0.62. Therefore, it is anticipated the proposed TE dehumidifier concept will contribute to the air conditioning system’s reduction of room humidity. 

scholarly journals Method for increasing the dynamic characteristics of thermoelectric coolers

2021 ◽  
Vol 4 (4) ◽  
pp. 354-367
Author(s):  
Yurii I. Zhuravlov
Keyword(s):  
Dynamic Characteristics ◽  
Thermoelectric Materials ◽  
Operating Mode ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Limiting Factors ◽  
Maximum Temperature ◽  
Thermoelectric Cooler ◽  
Modes Of Operation ◽  
Thermoelectric Coolers

The influence of the efficiency of the initial thermoelectric materials on the dynamics of the functioning of the thermoelectric cooling device for various characteristic current modes of operation in the range of operating temperature drops and heat load at a given geometry of thermoelement legs is considered. The parameters of thermoelectric materials of thermoelements are conventionally divided into three groups: used for batch production, laboratory research and maximum values. The criterion for choosing the operating mode of the thermoelectric cooler takes into account the mutual influence and weight of each of the limiting factors. Since the design conditions can be very diverse, simultaneously varying several limiting factors (constructive, energy and reliability), you can choose the most rational mode of operation. The analysis was carried out for typical current modes of operation of thermoelectric coolers: maximum cooling capacity, maximum cooling capacity at a given current, maximum coefficient of performance, minimum failure rate. It is shown that with an increase in the efficiency of the initial thermoelectric materials, the time for reaching the stationary operating mode of the thermoelectric cooler, the required number of thermoelements, and the maximum temperature difference increase. A method is proposed for reducing the time constant of thermoelectric coolers due to the revealed relationship between the efficiency of thermoelectric materials and the dynamic characteristics of thermoelements. It is shown that an increase in the dynamic characteristics of thermoelectric coolers is achieved without changing the design documentation, manufacturing technology and additional climatic and mechanical testing of products.

Storage stability of raw chevon chunks packaged in composite, bioactive films at refrigeration temperature

2014 ◽  
Vol 54 (9) ◽  
pp. 1328 ◽  
Author(s):  
Manish Kumar Chatli ◽  
Surabhi Kaura ◽  
Mohan Jairath ◽  
Nitin Mehta ◽  
Pavan Kumar ◽  
...  
Keyword(s):  
Water Activity ◽  
Sensory Quality ◽  
Storage Stability ◽  
Composite Films ◽  
Storage Period ◽  
Thiobarbituric Acid ◽  
Quality Parameters ◽  
Plate Count ◽  
Goat Meat ◽  
Overall Acceptability

Storage stability of raw chevon (goat meat) chunks wrapped in preformed, bioactive, biodegradable films based on composite starch–chitosan and impregnated with nisin (60 000 IU/g; T-1) and cinnamaldehyde (0.5% v/v; T-2) was evaluated relative to unwrapped product (control) under aerobic refrigeration (4°C ± 1°C) conditions for 10 days. Samples were taken on Days 1, 4, 7 and 10 to assess various physicochemical, microbiological and sensory quality parameters. Water activity and pH of raw chevon chunks followed a decreasing trend during storage under all packaging conditions; the rate of decrease of water activity was higher (P < 0.05) in the control than in bio-packaged products. Values of thiobarbituric acid reactive substances increased throughout storage and were lowest in T-2 and highest in the control. Extract release volume decreased throughout storage under all packaging conditions; however, it was higher (P < 0.05) in bio-packaged products than the control. Microbial quality was better in bio-packaged products than the control throughout storage. Standard plate count was 2.09 log10 cycles lower in T-2 than the control, and coliform count was lower by log10 2.31 cfu/g in T-2 and log10 1.88 in T-1 than the control on Day 7 of storage. Staphylococcus counts were lower (P < 0.05) in bioactive-packaged products than the control throughout the storage period. Sensory quality attributes colour, odour, texture and overall acceptability were better maintained in bio-packaged products than the control during storage, and maximum scores were awarded to T-2. The results indicate that starch–chitosan composite films impregnated with cinnamaldehyde can be used for the packaging of raw goat meat and successfully extend storage life by inhibiting the colour, oxidative and microbial deteriorative changes under refrigeration.

Coefficient of Performance of Thermoelectric Cooling on Nanofluids

2013 ◽  
Vol 459 ◽  
pp. 91-99
Author(s):  
Somchai Maneewan ◽  
Atthakorn Thongtha ◽  
Chantana Punlek
Keyword(s):  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Heat Sink ◽  
Cooling System ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cold Side ◽  
Input Condition ◽  
Current Input ◽  
Experimental Comparisons

This paper reports on experimental comparisons of coefficient of performance (COP) of a thermoelectric coolingsystem which cooled the hot side of the TEC by water (wc), ethylene glycol (egc) and nanofluids (nfc) The nanofluids is composed of ethylene glycol with silver nano(35 nm).The TEC was composed of the TE cooling modules, heat exchanger, and the air cooled heat sink at the cold side of the TE modules.Experiments were conducted with various current input 1 - 4.5 A to find out the optimum current input condition. To consideration of cooling capacity and COP of system was measured the hot and cold side temperature of TEC. Results shown that, the cooling capacity was increased with current input. The maximum cooling capacity of nfc, egc and wc are about 72, 62 and 41 W, respectively. Considered with highest COP found that the optimum current input is approximately 2.5 A. The maximum COP of nfc, egc and wc are about 2.01, 1.7 and 1.12, respectively. Therefore, the proposed TEC-nfc concept is expected to contribute to wider applications of the TE cooling system.

Desiccant Degradation in Desiccant Cooling Systems: A System Study

1993 ◽  
Vol 115 (4) ◽  
pp. 237-240 ◽  
Author(s):  
A. A. Pesaran
Keyword(s):  
Cooling System ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Thermal Coefficient ◽  
Ventilation Mode ◽  
Worst Case ◽  
Cooling Systems ◽  
Degradation Data ◽  
Percent Loss ◽  
The Impact

We predicted the impact of desiccant degradation on the performance of an open-cycle desiccant cooling system in ventilation mode using the degradation data on silica gel obtained from a previous study. The degradation data were based on thermal cycling desiccant samples and exposing them to ambient or contaminated air. Depending on the degree of desiccant degradation, the decrease in the thermal coefficient of performance (COP) and the cooling capacity of the system for low-temperature regeneration was 10 percent to 35 percent. The 35 percent loss occurred based on the worst-case desiccant degradation scenario. Under more realistic conditions the loss in system performance is expected to be lower.

Thermodynamic Analysis of TEG-TEC Device Including Influence of Thomson Effect

2018 ◽  
Vol 43 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Yuanli Feng ◽  
Lingen Chen ◽  
Fankai Meng ◽  
Fengrui Sun
Keyword(s):  
Thermoelectric Generator ◽  
Cooling Capacity ◽  
Thermodynamic Theory ◽  
Optimal Performance ◽  
Coefficient Of Performance ◽  
Junction Temperature ◽  
Thermoelectric Cooler ◽  
Thomson Effect ◽  
Equilibrium Thermodynamic ◽  
Cold Junction

AbstractA thermodynamic model of a thermoelectric cooler driven by thermoelectric generator (TEG-TEC) device is established considering Thomson effect. The performance is analyzed and optimized using numerical calculation based on non-equilibrium thermodynamic theory. The influence characteristics of Thomson effect on the optimal performance and variable selection are investigated by comparing the condition with and without Thomson effect. The results show that Thomson effect degrades the performance of TEG-TEC device, it decreases the cooling capacity by 27 %, decreases the coefficient of performance (COP) by 19 %, decreases the maximum cooling temperature difference by 11 % when the ratio of thermoelectric elements number is 0.6, the cold junction temperature of thermoelectric cooler (TEC) is 285 K and the hot junction temperature of thermoelectric generator (TEG) is 450 K. Thomson effect degrades the optimal performance of TEG-TEC device, it decreases the maximum cooling capacity by 28 % and decreases the maximum COP by 28 % under the same junction temperatures. Thomson effect narrows the optimal variable range and optimal working range. In the design of the devices, limited-number thermoelectric elements should be more allocated appropriately to TEG when consider Thomson effect. The results may provide some guidelines for the design of TEG-TEC devices.

scholarly journals Application of Propolis Extract in Gelatin Coatings as Environmentally Friendly Method for Extending the Shelf Life of Pork Loin

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 979
Author(s):  
Monika Marcinkowska-Lesiak ◽  
Iwona Wojtasik-Kalinowska ◽  
Anna Onopiuk ◽  
Magdalena Zalewska ◽  
Andrzej Poltorak
Keyword(s):  
Shelf Life ◽  
Storage Period ◽  
Thiobarbituric Acid ◽  
Quality Parameters ◽  
Plate Count ◽  
Propolis Extract ◽  
Overall Acceptability ◽  
Maximum Inhibition ◽  
Aerobic Plate Count ◽  
Meat Samples

This study evaluates the effects of gelatin coating enriched with ethanolic propolis extract (PE) at 1%, 2% or 3% (w/v) on the quality parameters of pork meat during storage at 2 °C. Physical (pH, weight loss, color) and chemical parameters (percentage contents of metmyoglobin (MetMb), along with thiobarbituric acid reactive substances (TBARS)) were measured, and microbiological (total aerobic plate count (TAPC)) analysis, as well as consumer evaluation, was carried out every four days during the storage period of twelve days. The results indicated that the proposed treatments affected (p < 0.05) the quality characteristics of meat samples. The high prevention of physicochemical alterations and maximum inhibition of microorganisms was obtained for samples stored in gelatin coatings containing 2% and 3% PE. Additionally, despite a slight deterioration in odor on Day 4 in the P3 group, no negative changes in overall acceptability of the P2 and P3 groups compared to uncoated samples were observed. The obtained results indicate a significant role of propolis extract incorporation into gelatin packaging to extend the shelf life of stored pork.

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