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19ТЕХНИЧЕСКИЕ НАУКИ
USING ALTERNATIVE ENERGY FOR FUEL CONSUMPTION OPTIMISATION ON REFRIGERATION SYSTEM OF ISOTHERMAL TRUCKS Tursunov О.А.
Tursunov Oybek Abduxalim ugli - Assistant Lecturer, AUTOMOTIVE ENGINEERING DEPARTMENT, ANDIJANMACHINE-BUILDING INTITUTE, ANDIJAN, REPUBLIC OF UZBEKISTAN
Abstract: it is well known that most perishable food products are transported with refrigerated trucks. Due to the running the refrigeration system of refrigerated trucks, additional energy costs are reqired. In Uzbekistan, there are more than 300 sunny days and using solar energy to refrigerate the isothermal trucks' board. The feasibility study was carried out on using solar energy in the refrigeration system of isothermal trucks. In this article, the technical and economical properties of transport applications of solar energy were analyzed. Some results and the design of proposed additional parts were given. Keywords: solar energy, solar panel, refrigeration, isothermal trucks.
UDC 629.3
Introduction.
As known, the low temperature retention in the refrigerators can be achieved by using a compressor cooling device that can drive a car engine or an autonomous engine [2].
There are two type of refrigerating units: independent refrigeration units and non-independent refrigeration units. Independent refrigeration units are run by an additional engine or electric motor. Non-independent refrigeration units are run by the engine of a car.
As the research object, the refrigeration unit of Isuzu NQR 71 PL truck which is manufactured in Uzbekistan was selected. The car's carrying capacity is 3000 kg and body temperature is between 0 ° C and -15 ° C [4]. At full load, the car consumes average 13kg of diesel fuel per 100 km in the absence of a refrigeration unit. When running with a refrigeration unit, the car consumes 15 kg of diesel per 100 km [3].
Methodology.
The new construction was designed in ordert to operate the refrigeration unit with electric motor whis is powered by solar panels set on the roof of the truck. According to the new design, the refrigeration unit will be powered by thin elastic solar panels (PV) set on the roof (calculated 10.3 m2), an additional spare battery stores the energy generated by PV panels and the refrigeration unit will be driven by stored energy when to reduce the fuel consumption. The calculations shows that 16 elastic PV panels with a capacity of 100 W and a weight of 1.35 kg with each size 1134x544x3 mm are needed to cover all surface of a roof of the truck. On the basis of the calculations, the battery with an energy storage capacity of 600 A/h, 24V Li-ion was selected and placed two in the lower part of the body on board.
The existing refrigerator system of the car is equipped with a engine-driven compressor. Thus, it requires an additional electric motor to operate it with electricity stored in the buttery. Depending on the maximum power required for the compressor, an electromotor was selected with characteristic: 24V; 4000W; 3000rpm. An electromotor is connected to the compressor via a belt and electromagnetic pulley. At the same time, the compressor should be able to driven by the car engine when the battery is low enough. In order to do this, an additional simple pulley is mounted on the existing electromagnetic pulley of the compressor, and is connected to the electromagnetic pulley of the electromotor via the belt. The wires connecting the electromagnetic pulley are connected to the circuit that when the battery does not have enough energy, it will disconnect the electromotor and the electromagnetic pulley from the source. And the electromagnetic pulley of the compressor is activated and it will be driven by a car engine.
The selected electromotor is mounted near the engine's frame with an additional designed base (Figure 2 b).
Findings and discussion.
The energy consumption for refrigeration of different type of perishable products was differentiated as below:
- refrigerating fruits;
- refrigerating meat and meat products;
- refrigerating milk and milk products;
as well as calculated 3000 kg of each to decline for 20°C with the formula (1).
Q=CM(TrT2) (1)
Q - the amount of energy required for cooling (or heating), C - Specific heat capacity, M -load mass (3000 kg), Tj - initial temperature, T2 - temperature after cooling (or heating).
Depending on the calculations, the energy consumption for refrigerating 3000kg products are below respectively:
- Fruit - 219600 kJ (61 kW);
- Meat and meat products - 168000kJ (46.6 kWh);
- Milk and milk products - 180000 kJ (50 kWh);
Considering the optimal specific fuel consumption of chosen truck "Isuzu NQR 71 PL" is 123.0 gr/kWh, the additional fuel consumption for refrigerating the total load will be below respectively:
- Fruit - 7503g ~ 7.5 kg;
- Meat and meat products - 5731g ~ 5.7 kg;
- Milk and milk products - 6150g ~ 6.1 kg;
Finally, as a result of using stored 28.8 kW power in two additional batteries (2x600Ax24V=28.8 kW), total 3.5 kg ~ 4.11 L fuel will be economized per full charge of butteries. Recharging time of batteries by PV panels depends on a location and day or night operation of the car. Conclusion.
The conclusion is that, according to the theoretical calculations, this system will be able to operate the refrigerator independently 4 hours when the buttery is fully charged or about 8-10 hours when operated by regimes. This will certainly have a positive impact on fuel consumption.
References
1. Tursunov O. Solar Assisted Refrigeration System for Transport Applications. Master thesis. AndMI, 2017.
2. Xoliqov N. Using a Modern Hybrid Compressors in Isothermal Trucks. Bachelor thesis. AndMI, 2018.
3. Karimov B. Design of an Electrically Driven Refrigeration System with Solar Energy. Bachelor thesis. AndMI, 2018.
4. SamAuto. [Electronic resource]. URL: https://samauto.uz/transport/item/7/ (date of access: 06.06.2020).
5. REEFERVAN. [Electronic resource]. URL: https://www.reefer-van.com/info/advantages-and-disadvantages-of-independent-re-38258012.html/ (date of access: 06.07.2020).
6. Numonov M.Z. Methods of ensuring the design of car parts on a computer // Universum: technical sciences: Electron. scientific. Journal, 2020. № 7 (76). [Electronic resource]. URL: https://7universum.com/ru/tech/archive/item/9957/ (date of access: 28.12.2020).
7. Tursunov O., Kholikov N., Vokhobov R. Solar energy applications for refrigerated trucks // Bulletin of Science and Education, 2020. № 11(89). [Electronic resource]. URL: http://scientificjournal.ru/images/PDF/2020/89/VN0-11-89-m-.pdf/ (date of access: 28.12.2020).
