Prediction of B20 Storage Tank Precipitate Removal Based on Biodiesel Monoglyceride Content

Precipitate in B20 fuel stored in storage tanks can accumulate at the bottom level of the tank and affect the fuel filter, clogging in the fuel distribution and engine system. This study examines the precipitate formation prediction in B20 fuel based on the monoglyceride content in biodiesel. This research used a modified CSFT method of ASTM D7501 for the precipitation test. Monopalmitin was added to biodiesel with a variation of monoglyceride content. Each biodiesel sample was then blended with petroleum diesel fuel to produce two groups of samples. Each sample was separately soaked in the cooling chamber at constant and room temperature for 21 days. The bottom layer of each B20 fuel sample stored in the measuring cylinder was then pipetted and filtered, washed with petro-ether, vacuum-dried, and weighed for a constant amount of precipitate retained on the filter. The simulation results show that the ratios between the amount of collected precipitate at the bottom layer of the 2-liter measuring cylinder and the total amount of collected precipitate for the 2-liter measuring cylinder increased with the monoglyceride content biodiesel. This ratio was used to predict the amount of accumulated sludge for a given volume of B20 fuel loaded into the storage tank. This study shows the effect of monoglyceride content on the precipitation behaviour in the storage tank concerning general tank storage dimension parameters and B20 loading frequency. This approach can be applied to estimate the sludge removal frequency for biodiesel storage.

Estimation of coefficient of performance of thermoelectric cooler using a 30 W single-stage type

In this study, a single stage thermoelectric cooler (TER, of size: 21 × 14.2 × 13.5 cm) with thermoelectric module (TEM, of type inbc1-127. 05 with size 40 × 40 × 4.0 mm) and applied electrical power of 30 W and current of 2.5 A, was adopted to estimate the coefficient of performance (COP) of thermoelectric refrigerator (TER). The TER uses a fan to cool the heat exchange region of the TEM. The temperature of the fruit/vegetable samples used in this study was taken before and after cooling for a specific period. The temperatures at both the hot and cold sides of the TEM were also taken at every specific cooling period. The experimented TER can cool vegetable/fruit from about 27 to 5°C within 3 h. The aim of this study is to determine the COP of TER to ascertain the possible applications. The temperature gradient at the heat exchange section of TEM was used to estimate the average theoretical COP to be 0.99, the heat extracted from the cooling chamber and the power supplied was used to estimate the average practical cooling COP to be 0.52; which is within 0.4–0.7 standard COP for a single stage type of TER.

Experimental Study of Thermal Performance of Different Fruit Packaging Box Designs

Packaging was recently identified as an essential element in addressing the key challenge of sustainable food supply and is gaining interest among researchers. It is a central element in food quality preservation due to its role in heat and mass exchange with the external atmosphere, contributing to the preservation of food quality during storage and extending food shelf life. This work proposes three new packaging configurations with the same size but different geometry and ventilation hole sizes and geometry, that change the conditions in which the heat and mass exchange occurs, during either the cooling period of fruits, inside the cooling chamber, or during the period when the packaging is exposed to ambient conditions, outside the cooling chamber. For this purpose, packages with fruit models that replicate the properties of real fruit were subjected to a cooling process inside a cooling chamber for 8 h. Subsequently, during the heating phase, the packages were exposed to ambient conditions for 10 h. Thermal conditions were also monitored, both inside and outside the chamber. Additionally, for comparative purposes, the thermal behavior of commercial packaging was also evaluated for the same operating conditions in the cooling and heating phases. The results show that the new packages do not substantially promote the preservation of fruits in the cooling phase, but in the heating phase, they ensure an extension of the period with proper thermal conditions of up to 50% in relation to the conventional packaging. This result is particularly important since the heating phase, in which fruits are outside the storage chamber, is the period with the greatest impact on the fruits’ useful life.

AIR-THERMAL MODES OF SOY SEEDS COOLING AFTER HEAT TREATMENT

In feed production, scientists suggest using high-quality plant culture, soy, to replace animal protein. Soy cannot be fed without pre-heat treatment due to the presence of anti-nutritional substances in it. Analysis of existing technology has shown that micronization, roasting, ultra-high-frequency processing, extrusion, autoclaving, and others are used to remove anti-nutritional substances. These methods are energy-intensive and have a complex design. (Research purpose) The research purpose is in developing a scheme and a working sample of a plant for cooling soybeans using a non-water vibrating conveyor and conduct research on its operation. (Materials and methods) Authors applied methods of system analysis and synthesis of existing knowledge in the field of ongoing research on the development of energy-saving soybean cooler, based on the provisions of the theory of heat and mass transfer. The article presents flow diagram of the cooling of soy. The vibrations of the chute of a non-drive conveyor in the cooling chamber are carried out from the vibration drive of the main conveyor due to the use of the reactive energy of its spring. (Results and discussion) It was revealed experimentally that in regions with a moderate climate and an outdoor temperature of 8-10 degrees Celsius, tempered soy can be cooled to the normalized values when it moves in the cooling chamber for 105-140 seconds. In regions of the country with a long period of high temperatures (20-25 degrees Celsius) of outdoor air, the cooling efficiency of tempered soybeans decreases. (Conclusions) The article presents the design parameters of the soybean cooling chamber for warm climate conditions. Authors developed and tested a working sample of the installation. The proposed technical solution provides a reduction in energy consumption compared to traditionally used equipment by up to 30 percent.

An intelligent loader-digger heat balance system based on simulation and wireless sensor networks

High temperature of the radiator group is harmful to the power system and hydraulic system. In order to improve the heat dissipation performance of the loader, the flow field characteristics of the cooling chamber are analyzed by simulation and heat balance test. Firstly, the mathematical model of heat flow is established. Secondly, the flow field in the cooling chamber under different speeds is simulated based on CFX. And then the influence of fan position and internal flow field distribution on radiator performance is studied. Through the simulation of four different distances, it is concluded that the optimal distance between cooling fan and radiator is 76 mm. Finally, the heat balance test system based on wireless sensor network is established, and the simulation results are verified. The test results show that the heat dissipation performance of the whole machine meets the requirements after optimization. In this paper, the proposed scheme can dynamically adjust the heat dissipation performance and make the loader excavator in an efficient and energy-saving operation state.