scholarly journals Hybrid microwave with heat recovery for an efficient drying process

2019 ◽  
Author(s):  
Willem Peter Rien Deleu ◽  
Vincent Goovaerts ◽  
Carlo Groffils
Keyword(s):  
Heat Exchange ◽  
Electric Energy ◽  
Electrical Energy ◽  
Hot Water ◽  
Microwave Cavity ◽  
Drying Time ◽  
Hot Air ◽  
The Sixties ◽  
Long Time ◽  
Microwave Process

Microwave technology has come a long way from the sixties when the first microwave ovens were developed. This first generation of microwave ovens uses only microwaves to heat the substrate and with an efficiency of around 63% in converting electrical energy to microwaves, this means 37% of the electric energy is lost as heat. The first improvement to this system “second generation” is using hybrid heating with both microwaves and hot air. The hot air in this case is simply the air used to cool the magnetron and transformers that is blown into the microwave cavity. The 37% of lost energy can thus be reused. The first role of the hot air current is to remove moisture from the cavity to avoid condensation on the (cold) cavity walls. The second role is to insulate the hot product from the cold environment and prevent energy loss. The third role is increasing evaporation speed; this decreases drying time and can also keep the drying temperature low through evaporative cooling. Low drying temperatures are favored in many processes especially with food as it delivers a superior dry product.The “third generation” utilizes an additional heat exchange to further increase the system’s efficiency. The hot (wet) exhaust air is not fully saturated yet so it can be used to preheat the substrate before it enters the microwave cavity. A good example is thawing and preheating frozen starting material. If water cooled magnetrons are used, the hot air is replaced by hot water instead for the heat exchange. Microwave processes are generally much faster resulting in smaller machines and reduced operational area. When designing a microwave process all these factors need to be taken into account to result in the cheapest and most robust process. As heat exchange generally takes a long time, it should only be done to a degree that it does not slow down the microwave process.

scholarly journals AUDIT ENERGI PADA SEBUAH HOTEL

2012 ◽  
Vol 16 (3) ◽  
pp. 131
Author(s):  
Didik Ariwibowo
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Savings ◽  
Electric Energy ◽  
Electrical Energy ◽  
Hot Water ◽  
Electrical Energy Consumption ◽  
Energy Audit ◽  
Electric Energy Consumption ◽  
Pumping System

Didik Ariwibowo, in this paper explain that energy audit activities conducted through several phases, namely: the initial audit, detailed audit, analysis of energy savings opportunities, and the proposed energy savings. Total energy consumed consists of electrical energy, fuel, and materials in this case is water. Electrical energy consumption data obtained from payment of electricity accounts for a year while consumption of fuel and water obtained from the payment of material procurement. From the calculation data, IKE hotels accounted for 420.867 kWh/m2.tahun, while the IKE standards for the hotel is 300 kWh/m2.tahun. Thus, IKE hotel included categorized wasteful in energy usage. The largest energy consumption on electric energy consumption. Largest electric energy consumption is on the air conditioning (AC-air conditioning) that is equal to 71.3%, and lighting and electrical equipment at 27.28%, and hot water supply system by 4.44%. Electrical energy consumption in AC looks very big. Ministry of Energy and Mineral Resources of the statutes, the profile of energy use by air conditioning at the hotel by 48.5%. With these considerations in the AC target for audit detail as the next phase of activity. The results of a detailed audit analysis to find an air conditioning system energy savings opportunities in pumping systems. Recommendations on these savings is the integration of automation on the pumping system and fan coil units (FCU). The principle of energy conservation in the pumping system is by installing variable speed drives (VSD) pump drive motor to adjust speed according to load on the FCU. Load variations FCU provide input on the VSD pumps to match. Adaptation is predicted pump can save electricity consumption up to 65.7%. Keywords: energy audit, IKE, AC

scholarly journals Modifikasi Pengering Tipe Tray Dryer Dengan Penambahan Insulator

2020 ◽  
Vol 4 (4) ◽  
pp. 422-431
Author(s):  
Iqbal Fahri Tobing ◽  
Mustaqimah Mustaqimah ◽  
Raida Agustina
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Performance Test ◽  
Raw Materials ◽  
Electric Energy ◽  
Electrical Energy ◽  
Energy Calculation ◽  
Drying Process ◽  
Drying Time ◽  
Drying Efficiency

Abstrak. Pengering tipe Tray Dryer merupakan salah satu alat pengering rak atau pengering kabinet yang dapat digunakan untuk mengeringkan berbagai jenis bahan baku makanan. Alat pengering ini dirancang dengan tipe paralel flow tray dimana udara panas yang dihasilkan akan disirkulasikan sejajar dengan permukaan rak pengering dan bekerja menggunakan sumber energi listrik. Penelitian ini bertujuan untuk memodifikasi pengering tray dryer dengan penambahan insulator dan mengetahui konsumsi energi alat pengering tray dryer pada pengeringan kunyit. Parameter pengujian uji kinerja alat tanpa bahan meliputi distribusi suhu, kelembaban relatif dan kecepatan aliran udara dan untuk perhitungan konsumsi energi meliputi penggunaan energi listrik, perhitungan energi thermal, energi mengeringkan bahan, energi untuk menguapkan air bahan, efisiensi pengeringan, energi kipas dan kehilangan energi melalui cerobong. Pada pengujian pengering tray dryer suhu yang digunakan adalah 55°C. Hasil penelitian menunjukkan bahwa secara fungsional dan struktural alat pengering tray dryer setelah dimodifikasi dengan melapisi dinding luar ruang pengering dapat beroperasi dengan baik, proses pengeringan lebih cepat dan energi yang digunakan juga sedikit dibandingkan dengan sebelum dimodifikasi. Konsumsi energi listrik pada alat pengering tray dryer setelah dimodifikasi pada saat proses pengeringan dengan suhu 35oC selama 6,5 jam sebesar 35,33 kWh (127,2 MJ), pada suhu 45oC sebesar 24,26 kWh (88,06 MJ) dengan lamanya pengeringan selama 4,5 jam dan suhu 55oC sebesar 18,89 kWh (68,01 MJ) dengan lama pengeringan selama 3,5 jam, hal ii disebabkan lama pengeringan merupakan salah satu faktor yang menyebabkan besar kecilnya konsumsi energi listrik. Konsumsi energi thermal selama proses pengeringan dengan suhu 35°C adalah sebesar 17,53 MJ, suhu 45°C sebesar 19,54 MJ dan suhu 55°C sebesar 21,34 MJ. Berdasarkan hasil kalkulasi antara energi listrik dan energi thermal didapatkan efisiensi pengeringan pada suhu 35°C sebesar 27,80%, suhu 45°C sebesar 22,2% dan suhu 55°C sebesar 31,4%.Modification Of Tray Dryer With InsulatorAbstract. Tray Dryer is a type of dryer or cabinet dryer that can be used to dry various types of food raw materials. This dryer is designed with a parallel flow tray type where the hot air generated will be circulated parallel to the surface of the drying rack and work using an electric energy source. This study aims to modify the tray dryer with the addition of an insulator and determine the energy consumption of dryer dryers in turmeric drying. The test parameters of the performance test of equipment without material include temperature distribution, relative humidity and air flow velocity and for the calculation of energy consumption including the use of electrical energy, thermal energy calculation, energy drying material, energy to evaporate material water, drying efficiency, fan energy and energy loss through chimney. In testing the tray dryer dryer the temperature used is 55 ° C. The results showed that functionally and structurally the tray dryer after being modified by covering the outer walls of the drying chamber could operate well, the drying process was faster and the energy used was also less compared to before it was modified. Electric energy consumption in the tray dryer after being modified during the drying process with a temperature of 35oC for 6.5 hours amounted to 35.33 kWh (127.2 MJ), at a temperature of 45oC of 24.26 kWh (88.06 MJ) with a duration drying for 4.5 hours and a temperature of 55oC of 18.89 kWh (68.01 MJ) with a drying time of 3.5 hours, this is due to the length of drying is one of the factors causing the size of the electrical energy consumption. The consumption of thermal energy during the drying process with a temperature of 35 ° C is 17.53 MJ, a temperature of 45 ° C is 19.54 MJ and a temperature of 55 ° C is 21.34 MJ. Based on the results of calculations between electrical energy and thermal energy obtained drying efficiency at a temperature of 35 ° C at 27.80%, a temperature of 45 ° C at 22.2% and a temperature of 55 ° C at 31.4%

scholarly journals Optimization of the energy system of the Taimyr coal basin through energy storage

2021 ◽  
Vol 266 ◽  
pp. 04012
Author(s):  
A. Deev ◽  
V. Lebedev
Keyword(s):  
Energy Storage ◽  
Power Plant ◽  
Power System ◽  
Electric Energy ◽  
Lithium Ion ◽  
Electrical Energy ◽  
Energy System ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Coal Basin

This article examines the influence of energy storage on the possibility of increasing the efficiency of a power plant on the example of the model of the power system of the Taimyr coal basin. The main elements of the power system calculated in this paper included: household consumers (township of Dixon), industrial consumers (coal mining enterprises), sources of thermal and electric energy (coal-fired combined heat and power plant). Storage equipment was selected for the storage of thermal and electrical energy in the power system, such as energy storage systems based on lithium-ion batteries and hot water storage tanks. The changes in the operation modes of the combined heat and power plant during the introduction of battery systems in the power system were evaluated, and the efficiency of the combined heat and power plant was calculated for various modes of energy storage.

scholarly journals Reducing the energy consumption of the aerodynamic heating dryer

2021 ◽  
Vol 1 (1) ◽  
pp. 81-87
Author(s):  
A.I. Kupreyenko ◽  
◽  
KH.M. Isayev ◽  
S.KH. Isayev ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Thermal Resistance ◽  
Electric Energy ◽  
Electrical Energy ◽  
Ambient Air ◽  
Aerodynamic Heating ◽  
Current Transformers ◽  
Drying Time ◽  
Drying Chamber

A promising direction in the development of drying plants in the technologies of processing fruit and berry raw materials is the use of aerodynamic heating dryers. They implement the principle of transformation of electrical energy consumed to drive a centrifugal fan into thermal energy due to mutual friction of air flows circulating in a closed chamber. In this case, the overwhelming part of the electrical energy supplied to the rotor is spent on overcoming aerodynamic losses in the flow path of the impeller and in the drying chamber. To reduce the energy consumption of the drying process by reducing the energy consumption for heating the drying agent in the drying chamber, it is proposed to utilize the heat of the spent drying agent by equipping the dryer with a combined heat exchanger. It combines a plate heat exchanger and a solar air collector. The aim of the study was to analyze the efficiency of using a combined heat exchanger to reduce the energy consumption of an aerodynamic dryer when drying apples. The operation of the drying plant was investigated with and without a combined heat exchanger. To record the parameters of the drying agent, the environment, and the consumption of electric energy, an eight-channel TRM-138 thermoregulator meter with thermal resistance sensors and an electric energy meter with current transformers were used. An eight-channel TRM-138 thermoregulator meter with thermal resistance sensors and an electric en-ergy meter with current transformers was used to record the parameters of the drying agent, the en-vironment, and the consumption of electric energy. The research results showed that the use of a combined heat exchanger made it possible to increase the temperature of the drying agent entering the drying chamber by an average of 20 ºС relative to the ambient air temperature. A more intensive increase in the temperature of the drying agent when using a combined heat exchanger made it pos-sible to reduce the drying time by 3 hours. At the same time, electricity consumption decreased by 27.4%.

scholarly journals Effects of the Existence of Fan in the Wood Drying Room and the Performance of the Electric Energy Wood Dryer

2021 ◽  
Vol 03 (01) ◽  
pp. 83-92
Author(s):  
Wibowo Kusbandono ◽  
◽  
Petrus Kanisius Purwadi ◽  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Air Temperature ◽  
Electric Energy ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Wood Drying ◽  
Uniform Size ◽  
Drying Time ◽  
Compression Cycle

The purpose of this study is to determine the effect of the presence of a fan in the wood drying room in the drying time of wood. In addition, it is also to determine the performance of the steam compression cycle engine used in wood drying machines and the conditions of air entering and leaving the wood drying room. Wood drying machines work on a source of electrical energy. The research was conducted experimentally. Variations in the study were carried out on the presence of fans in the drying room: (a) there were no fans and (b) there were 2 fans. The dried object is a sengon wood board, which has a length of 2 m, a width of 20 cm, and a thickness of 2 cm. The number of wooden planks is 70 wooden planks of uniform size. The wooden planks before drying have a moisture content of 29.6%, and when dry, have a moisture content of 10%. The research gave the following results: (a) if there are 2 fans in the drying room, the time needed to dry the sengon wood planks is around 42.6 hours, whereas if there is no fan around 49.9 hours (b) the average Coefficient of Performance (COP) of the steam compression cycle engine is 10.65 (c) The air condition enters the drying room when there are 2 fans, has a dry ball air temperature of 40oC with a relative humidity of 32% RH and the air condition when it comes out, has a dry ball air temperature of 28oC with a relative humidity of 73% RH.

Innovation of Natural Preservation of Mackerel (Rastrelliger kanagurta) Using Coconut Coconut Ashes with Drying Time Variations on Hedonics

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Rika Agustina ◽  
Rita Sunartaty ◽  
Teuku Makmur
Keyword(s):  
Research Design ◽  
Block Design ◽  
Drying Time ◽  
Basic Ingredient ◽  
Randomized Block Design ◽  
Salt Substitute ◽  
Long Time ◽  
Time Variations ◽  
Rastrelliger Kanagurta

Coconut frond ash is one of the wastes from coconut trees which has not been maximally utilized. Coconut frond ash contains MgCl2 and KCl so that it can be used as a salt substitute in the process of preserving fish. In this study coconut frond ash was used as a basic ingredient for making dried mackerel with a long time of drying to storage. The purpose of this study was to determine the effect of drying time on mackerel storage. The research design used was a Randomized Block Design (RCBD) with 2 factors studied. The first factor is the drying time consists of 3 levels, namely P1 = 3 days, P2 = 4 days, P3 = 5 days. The second factor is storage which consists of 3 levels, namely S1 = 30 days, S2 = 60 days, S3 = 90 days. Each treatment was repeated 2 times to obtain 18 experimental units to observed hedonic tests. From the results of the study it can be stated that the treatment has a very significant effect (P≥0.01) on the hedonic test which includes (color, aroma, taste and texture).

DETERMINING THE PROFITABILITY OF GREENHOUSE ELECTROTECHNOLOGIES: A MODELING APPROACH

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Water System ◽  
Heat Pumps ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Artificial Lighting ◽  
Hot Air ◽  
Marketable Fruit

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.

scholarly journals Effect of Roof Cooling and Air Curtain Gates on Thermal and Wind Conditions in Stadiums for Hot Climates

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3941
Author(s):  
Fangliang Zhong ◽  
Hassam Nasarullah Chaudhry ◽  
John Kaiser Calautit
Keyword(s):  
Energy Consumption ◽  
Electric Energy ◽  
Building Energy ◽  
Future Research ◽  
World Cup ◽  
Air Curtain ◽  
Hot Air ◽  
Computational Fluid Dynamics Cfd ◽  
Energy Consumptions ◽  
The Spectator

To host the 2022 FIFA World Cup, Qatar is facing the greatest challenge in balancing the energy consumptions for cooling the stadiums and the thermal comfort for both players and spectators. Previous studies have not considered using a combined configuration of air curtain and roof cooling supply slot in stadiums to prevent the infiltration of outside hot air and reduce the cooling system’s energy consumption. This paper presents a Computational Fluid Dynamics (CFD) study of thermal and wind modeling around a baseline stadium and simulates the cooling scenarios of air curtains and roof cooling along with the energy consumption estimations for the World Cup matches using Building Energy Simulation (BES). Sensitivity analysis of different supply speeds and supply temperatures of air curtain gates and roof cooling was carried out, and the results showed that scenario six, which provides supply air of 25 m/s and 20 m/s at the roof and air curtain gates with a supply temperature of 10 °C, demonstrates optimal thermal performances on both the spectator tiers and the pitch. Compared with the baseline stadium performance, the average reductions in temperature on the pitch and spectator tiers under scenario six could reach 15 °C and 14.6 °C. The reductions in the Predicted Percentage of Dissatisfied values for the upper and lower tiers as well as the pitch were 63%, 74%, and 78%. In terms of the estimated energy consumptions, scenario six would consume electric energy per match at a rate of 25.5 MWh compared with 22.8 MWh for one of the stadiums in the 2010 South Africa World Cup and 42.0 MWh for the 2006 Germany World Cup. Future research is recommended to explore the influence of supply angle on air curtain gates and roof cooling supply slots’ performances.

Tube Banks Heat Transfer Enhancement Using Conical Fins

2010 ◽  
Author(s):  
Ignacio Carvajal-Mariscal ◽  
Florencio Sanchez-Silva ◽  
Georgiy Polupan
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Pressure Drop ◽  
Finned Tube ◽  
Hot Water ◽  
Experimental Results ◽  
Tube Bank ◽  
Finned Tubes ◽  
Tube Banks ◽  
Annular Fins

In this work the heat transfer and pressure drop experimental results obtained in a two step finned tube bank with conical fins are presented. The tube bank had an equilateral triangle array composed of nine finned tubes with conical fins inclined 45 degrees in respect with the tube axis. The heat exchange external area of a single tube is approximately 0.07 m2. All necessary thermal parameters, inlet/outlet temperatures, mass flows, for the heat balance in the tube bank were determined for different air velocities, Re = 3400–18400, and one constant thermal charge provided by a hot water flow with a temperature of 80 °C. As a result, the correlations for the heat transfer and pressure drop calculation were obtained. The experimental results were compared against the analytical results for a tube bank with annular fins with the same heat exchange area. It was found that the proposed tube bank using finned tubes with conical fins shows an increment of heat transfer up to 58%.

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