scholarly journals Пути совершенствования системы охлаждения двигателей легковых автомобилей

2020 ◽  
Author(s):  
V.P. Dmitrenko ◽  
I.M. Sotskaya ◽  
R.D. Adakin
Keyword(s):  
Heat Exchanger ◽  
Heat Accumulator ◽  
Coolant Pump ◽  
Automobile Engine ◽  
Warm Up ◽  
Engine Cooling ◽  
Toxic Gases ◽  
Environment Temperature ◽  
Engine Coolant ◽  
Cooling Cavity

Пуск автомобильного двигателя сопровождается интенсивным выбросом токсичных газов, особенно углеводородов и моноксидов углерода. Чем ниже температура окружающего воздуха, тем больше при прогреве холодного двигателя выбрасывается в атмосферу этих газов. Для сокращения времени прогрева двигателя после пуска рекомендуется на все автомобили устанавливать предпусковые подогреватели и аккумуляторы тепла. Для более эффективного прогрева двигателя в поддон необходимо установить теплообменник для подогрева масла. Турбокомпрессор должен иметь полость охлаждения корпуса подшипников, насос охлаждающей жидкости двигателя должен быть с электроприводом и с регулируемой частотой вращения. При предпусковом прогреве двигателя подогревателем этот насос при неработающем двигателе будет прокачивать горячую жидкость из теплообменника подогревателя через полость охлаждения двигателя, теплообменник масла в поддоне, полость охлаждения в корпусе подшипников турбокомпрессора. Горячие газы из камеры сгорания подогревателя необходимо использовать для подогрева нейтрализатора отработавших газов. Аккумулятор тепла целесообразно использовать в случае работы автомобиля с периодическими остановками, например, в режиме такси или при перевозке грузов. В этом случае перед пуском двигателя насос за несколько секунд перекачает горячую жидкость из аккумулятора в перечисленные выше полости и сократит время прогрева двигателя после пуска. Эти мероприятия позволят существенно сократить выбросы в атмосферу токсичных газов и повысить надёжность двигателей.Starting of an automobile engine is accompanied by an intense release of toxic gases especially hydrocarbons and carbon monoxides. The lower the environment temperature the more these gases are emitted when the cold engine warms up. To reduce the engine warm-up time after starting it is recommended to install preproduction heater and heat accumulators on all vehicles. For more efficient warming up of the engine it is necessary to install a heat exchanger in the oil pan to heat the oil. The turbocharger must have a cooling cavity for the bearing block, the engine coolant pump must have an electric driver and with an adjustable speed. When the engine is preheated by the heater, this pump when the engine is off will pump hot liquid from the heater heat exchanger through the engine cooling cavity, the oil heat exchanger in the pan and the cooling cavity in the turbocharger bearing block. Hot gases from the combustion chamber of the heater must be used to heat the exhaust gases catalyst. It is advisable to use the heat accumulator in case of operation of the vehicle with periodic stoppings for example in taxi mode or during transport of goods. In this case before starting the engine in a few seconds the pump pumps hot liquid from the accumulator into the cavities listed above and reduces the time of warming up the engine after starting. These measures will significantly reduce the emission of toxic gases into the atmosphere and increase the reliability of engines.

scholarly journals THE RESEARCH OF THE WORK OF THE HEAT ACCUMULATOR OF THE PRE-STARTING SYSTEM OF WORMING UP OF THE INTERNAL COMBUSTION ENGINE

2020 ◽  
Vol 42 (3) ◽  
pp. 76-83
Author(s):  
K. Lunyaka ◽  
O. Kliuiev ◽  
S. Rusanov ◽  
O. Kliuieva
Keyword(s):  
Heat Transfer ◽  
Heat Storage ◽  
Cooling System ◽  
Storage Material ◽  
Heat Accumulator ◽  
Operating Modes ◽  
Engine Cooling ◽  
Cooling Agent ◽  
Heat Storage Material ◽  
Engine Coolant

Problem statement. Starting internal combustion engines for a large car fleet at ambient temperature of less than 5 ºС requires considerable time; it leads to increased wear of the components of the connected engine pairs, increased fuel consumption during start-up and warm-up and increased emissions of harmful substances into the atmosphere with exhaust fumes. Therefore, prestart warming up   of car engines is given great attention. Actual scientific researches and issues analysis Recently, this problem has been solved by using heat accumulators, moreover, heat accumulators with heat storage material of a phase transition are given preference. The engine exhaust gases (temperature 600-700 ºС) or the engine cooling liquid (water,                 tosol cooling agent) are used as a heat transfer agent. Given the negative impact of high temperatures on the heat storage material, the metal of the heat storage structure and overheating (boiling) of the engine coolant, the first way has certain disadvantages. In this regard, we consider it more promising to use a liquid cooling engine as a coolant for a heat accumulator. High temperatures have no positive affect on the heat storage material, the metal of the heat storage structure and these are a cause for boiling a coolant –cooler of the engine. In this regard, we consider more promising to use a cooling fluid of the heat accumulator as a heat transfer agent. The aim of this work is to develop a new design of a heat accumulator for pre-starting warming up of a car engine, to make the experimental installation to research its work and conducting researches in order to find the time of charging and discharging of the heat accumulator, to construct operating modes during charging and discharging, to determine the necessary mass of the heat-accumulating material and the battery size. Base material The experimental installation was a closed system: the heat accumulator — a passage of the VAZ 2109 car engine cooling system. Taking into account the work peculiarities of the heat accumulator in the cooling system of the car engine, unlike other areas where all mass of the heat storage material constantly is in contact with the substance which the heat storage material giving up heat, in our case, the engine cooling liquid is located in the heat accumulator and in the cooling jacket. They mixes before starting the engine, while its temperature decreases. The time of charging and staying of the heat accumulator in the charged state has been determined, the operating modes during charging and discharging have been constructed, the necessary mass of the heat-accumulating material and the battery size has been determined.  Conclusions The experimental model of the heat accumulator of the pre-starting system of worming up of the engine of the car has been developed. This experimental model is included in a closed circuit with engine cooling system. On the model the researches of charging and discharging process of the heat accumulator have been conducted. The required time for these processes has been determined and on this basis the modes of operation of the heat accumulator - engine cooling system have been constructed. The temperatures of tosol cooling agent in the cooling system were calculated and it allowed finding mass (volume) of heat storage material of the heat accumulator and it served as the basis for determining the size of the heat accumulator. Establishment of a computerized control system on/off control of the heat accumulator in order to maintain the desired temperature of the engine coolant liquid using of heat storage material of phase transition and controlling this system using supplements to phones.

Performance Investigation of TiO2 Nanofluid Coolant for Automobile Cooling Applications

2015 ◽  
Vol 645-646 ◽  
pp. 444-448 ◽  
Author(s):  
Jin Mao Chen ◽  
Xiao Ying Sun ◽  
Guan Jun Leng ◽  
Jing Heng Feng
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Convective Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Convective Heat ◽  
Transfer Enhancement ◽  
Automobile Engine ◽  
Conductivity Enhancement ◽  
Engine Cooling ◽  
Engine Coolant

This study focused on the evaluation of TiO2 nanofluid coolant for automobile engine cooling applications. It was observed that, about 3% of thermal conductivity enhancement and above 10% convective heat transfer enhancement could be achieved with the usage of 1.0 wt.% TiO2 nanofluid coolant compared to base coolant without nanoparticles. More importantly, corrosion-inhibiting properties of TiO2 nanofluid coolant were investigated, which indicated that the nanofluid coolant possess the characteristics of a qualified engine coolant should have. The evaluation results showed that the nanofluid coolant could be a promising engine coolant for automobiles.

scholarly journals Experimental and numerical analyses to improve the design of engine coolant pumps

2020 ◽  
Vol 197 ◽  
pp. 06017
Author(s):  
Luigi Mariani ◽  
Marco Di Bartolomeo ◽  
Davide Di Battista ◽  
Roberto Cipollone ◽  
Fabrizio Fremondi ◽  
...  
Keyword(s):  
Dynamic Test ◽  
Time Instant ◽  
Pump Efficiency ◽  
Drive Cycle ◽  
Coolant Pump ◽  
Pump Speed ◽  
Engine Cooling ◽  
Speed Flow ◽  
Engine Coolant ◽  
Operating Points

In this paper, an experimentally based procedure is presented to re-orient the design point of the pump in order to minimize the energy absorbed during the homologation cycle or during any real driving one. During it, in fact, every benefit on the pump’s efficiency is appreciated and produces fuel consumption and CO2 reduction. The procedure takes the advantage from a dynamic test bench for coolant pump, realized and engineered at University of L’Aquila. It has been linked to a model-based methodology, which evaluates, according to a specified vehicle’s mission profile, the speed and load variation of the engine propelling the vehicle, and, therefore, the pump speed. The knowledge of the engine cooling circuit for closed and fully opened thermostat allows the calculation of the flow rates and pressure delivered in each time instant of the drive cycle. The speed-flow rate-pressure delivered pump profile has been reproduced on the bench, and all the relevant quantities have been measured: an exact evaluation of the scatter of the efficiency of the pump, the instantaneous power and the overall energy absorbed have been obtained. Results show how the pump efficiency is far from its Best Efficiency Point. This conclusion invited the Authors to reorient the design pump considering an operating condition, which has a greater occurrence among all the operating points characteristic of a drive cycle. Four pumps have been designed following this approach, showing a sensible reduction of the energy absorbed: this represents a key point also for pump electrification.

EFFECT OF CONDENSATION ON THE EFFICIENCY OF HEAT RECOVERY VENTILATORS FOR BROILER HOUSES

2013 ◽  
Vol 21 (02) ◽  
pp. 1350009 ◽  
Author(s):  
HWATAIK HAN ◽  
SANG-HOON NAM ◽  
GEON-SOO HAN
Keyword(s):  
Heat Exchanger ◽  
Relative Humidity ◽  
Latent Heat ◽  
Heat Recovery ◽  
Harsh Environments ◽  
Sensible Heat ◽  
Outdoor Temperature ◽  
Toxic Gases ◽  
Temperature Efficiency ◽  
Plate Type

This study experimentally investigates the effect of internal condensation on the performance of a heat recovery ventilator. Experiments were performed using a plate-type sensible heat exchanger element that was designed for very humid and dusty environments such as chicken broiler houses. The results of these experiments show that the temperature efficiency considering condensation is always greater than that without considering latent heat. As outdoor temperature decreases or indoor relative humidity increases, temperature efficiency increases owing to an increase in the rate of condensation. The present polypropylene-based sensible heat exchanger element could be a solution for harsh environments because it can discharge condensate water by gravity and is resistant to moisture and other toxic gases.

scholarly journals Effects of the exhaust gas heat recovery system with a plate heat exchanger on the warm-up performance characteristics of the gasoline engine

2018 ◽  
Vol 7 (2.12) ◽  
pp. 136
Author(s):  
Chan JungKim ◽  
Sank Wook-Han ◽  
Ki Hyun Kim ◽  
Moo Yeon Lee ◽  
Gee Soo Lee
Keyword(s):  
Heat Exchanger ◽  
Fuel Economy ◽  
Heat Recovery ◽  
Exhaust System ◽  
Plate Heat Exchanger ◽  
Exhaust Gas ◽  
Warm Up ◽  
Plate Heat ◽  
Recovery System ◽  
Heat Recovery System

Background/Objectives: To meet the regulations for the fuel economy, an EHRS (Exhaust gas Heat Recovery System, which was installed within the vehicle exhaust system and recovered the heat from the exhaust gas, were needed. The EHRS enabled the engine to achieve the fast warm-up performance for reducing friction loss during the cold start.The objective of this paper was to investigate the effects of the design parameters of the EHRS with a plate heat exchanger on the warm-up performance of a gasoline engine.Methods/Statistical analysis: The EHRS with the plate heat exchanger was manufactured and installed behind the catalyst in the exhaust system of the gasoline direct injection engine. The experimental study and multi-disciplinary analysis were carried out to investigate the effects of the EHRS on the warm-up performance of the engine, such as the coolant temperature, the exhaust gas temperature and the recovery heat at idle condition and the step-load condition.Findings: Because the recovery of heat was about 1. 7 kW at idle condition, the effect of the EHRS on the warm-up performance was negligible. However, due to 17.2 kW of the recovery of heat at the stepload condition of T=140 Nm at N=2,400 rpm, the EHRS enabled to shorten the warm-up time by 548 s comparison that of the base engine.Improvements/Applications: The fuel economy will be expected to be improved through an EHRS, which provides the improved combustion in the warm-up phase and a decrease in friction loss.  

CFD Analysis of Heat Exchanger and Aftercooler for Diesel Marine Engines

2006 ◽  
Author(s):  
Andrew S. Campbell ◽  
Jeff Ladendorf ◽  
Chenn Q. Zhou
Keyword(s):  
Heat Exchanger ◽  
Theoretical Calculations ◽  
Measurement Data ◽  
Feasibility Studies ◽  
Flow Property ◽  
Fundamental Understanding ◽  
Marine Engines ◽  
Computational Fluid Dynamics Cfd ◽  
Shell And Tube ◽  
Engine Coolant

Shell and tube heat exchangers and bar and plate aftercoolers are used in a diesel marine engine to remove heat from the engine coolant and to cool the pressurized air going into the engine. In order to improve the overall effectiveness of these two components, analyses have been performed using heat exchanger theory and the Computational Fluid Dynamics (CFD) software FLUENT®. Detailed information of flow property distributions and heat transfer was obtained in order to provide a fundamental understanding of the component operation. Comparisons have been made between CFD results, theoretical calculations, and measurement data. Parametric investigations and feasibility studies have been conducted to find optimum conditions for the engine and component performance.

A Thermodynamic Efficiency Concept for Heat Exchange Devices

1983 ◽  
Vol 105 (1) ◽  
pp. 199-203 ◽  
Author(s):  
L. C. Witte ◽  
N. Shamsundar
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Energy Use ◽  
Second Law Of Thermodynamics ◽  
Thermodynamic Efficiency ◽  
Second Law ◽  
Two Fluids ◽  
Environment Temperature ◽  
Efficiency And Effectiveness ◽  
The Mean

A thermodynamic efficiency based on the second law of thermodynamics is defined for heat exchange devices. The efficiency can be simply written in terms of the mean absolute temperatures of the two fluids exchanging heat, and the appropriate environment temperature. It is also shown that for a given ratio of hot to cold inlet temperatures, the efficiency and effectiveness for particular heat exchange configurations are related. This efficiency is compared to second-law efficiencies proposed by other authors, and is shown to be superior in its ability to predict the effect of heat exchanger parameter changes upon the efficiency of energy use. The concept is applied to typical heat exchange cases to demonstrate its usefulness and sensitivity.

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