Truck Encyclopedia (8): Truck radiator in all aspects

As we all know, limited by the efficiency of the internal combustion engine, a large amount of waste heat is generated when the car is working, and in order to ensure that the engine is at the ideal operating temperature, engineers equipped the engine with a series of heat dissipation systems.

Depending on the application, these cooling units serve the engine and transmission, the braking system, and the occupants.

In order to facilitate the explanation, we will divide these cooling units into vehicle cooling systems and in-vehicle comfort cooling systems according to the service objects, and we will talk about them in detail below.

▎ Without it, the truck can't move - the vehicle cooling system

● The backbone of heat dissipation: Engine radiator
 

The first is the condenser, the middle is the intercooler, and the last is the heat dissipation tank

Commonly known as a water tank, the heat dissipation medium is coolant. The excess heat in the engine is transferred to the air through the water circulation. There are also thermostats, water pumps and cooling fans that work together with the radiator to ensure that the temperature of the engine is controlled within a certain range within the design conditions.

Heat dissipation object: engine.

Purpose of heat dissipation: control the engine temperature within a reasonable range.

Poor heat dissipation: the water temperature of the engine rises, the power decreases, and even the cylinder is pulled and the tile is held, which damages the engine. On the contrary, the water temperature is low, the fuel consumption is large, and the engine running resistance is large.

● The icing on the cake Oil radiator

道依茨发动机的机Oil radiator (circled in green)

There are two types of heat dissipation methods for oil radiators: air-cooled and water-cooled. Its role is to control the oil temperature and help reduce the engine temperature, ensuring that the oil is in the optimal viscosity range and provides the best lubricating properties.

Most trucks are cooled by water cooling, sharing the engine cooling system.

Heat dissipation objects: engine, engine oil.

The purpose of heat dissipation: to ensure the lubrication performance of the oil.

Poor heat dissipation: Too high causes the viscosity of the oil to become smaller and lose its lubricating ability. Too low leads to a higher viscosity of the oil, which increases the resistance of the engine and also reduces the lubrication capacity.

● High-end high-grade transmission oil radiator

沃尔沃变速器的变Speeder oil radiator (circled in green)

The transmission oil radiator is the same as the oil radiator, and there are two ways: air cooling and water cooling.

Its role is to control the temperature of the transmission oil and ensure that the transmission oil is in the optimal viscosity range, providing the best lubrication and shifting performance.

东风天龙14挡手动Radiator mounted on the transmission (circled in green)

At present, there are fewer models with transmission oil radiators, and the models of Dongfeng Tianlong 14-speed manual transmissions are equipped with transmission oil radiators, which are dissipated by water cooling and share the engine cooling system.

Heat dissipation object: transmission and transmission oil.

The purpose of heat dissipation: to ensure that the transmission and transmission oil are at a reasonable working temperature.

Poor heat dissipation: Too high causes the viscosity of the oil to become smaller and lose its lubricating ability. Too low will increase the viscosity of the oil, which will increase the resistance to movement inside the transmission and also cause a decrease in lubrication capacity.

● Turbocharging essential intercooler

Intercooler for Volvo engines

Object of heat dissipation: air, specifically refers to the air that enters the combustion of the engine.

The purpose of heat dissipation: to ensure that the engine intake air temperature is within a reasonable range.

Poor heat dissipation: The inlet temperature is too high, and the engine power is reduced.

● Hydraulic retarder radiator

In addition to this, there is a hydraulic retarder on the truck that needs to dissipate heat, and its heat dissipation relies on the engine cooling system to work.
 

Radiator for hydraulic retarder

Hydraulic retarders generally rely on coolant to dissipate heat, which conducts heat to the coolant through the oil-coolant method, and then discharges it by the engine cooling system.

Object of heat dissipation: hydraulic retarder oil.

The purpose of heat dissipation: to ensure that the oil temperature of the hydraulic retarder is in a reasonable range and to ensure the normal operation of the hydraulic retarder.

Poor heat dissipation: Hydraulic retarder, loss of deceleration effect.

● ERG radiator

EGR cooling system (circled in red)

EGR is an exhaust gas recirculation system, the EGR shown here dissipates heat through the coolant, cools the exhaust gas discharged from the engine and enters the engine combustion for a second time, so as to increase the proportion of carbon dioxide in the combustion process of the engine, reduce the working temperature of the engine, reduce the generation of nitrogen oxides, and make the engine more environmentally friendly.

Heat dissipation target: Engine exhaust gases that need to be recycled and combusted.

Purpose of heat dissipation: increase the carbon dioxide content in the intake air, reduce the operating temperature of the engine, reduce the generation of nitrogen oxides, and make the engine more environmentally friendly.

Poor heat dissipation: The engine temperature rises and the emissions are too polluted.

● Air radiator

In addition to the above cooling systems around the engine and transmission, there are also air spiral pipes that dissipate heat from the compressed air.

Heat dissipation object: compressed air for vehicles.

Purpose of heat dissipation: to reduce the temperature of the compressed air.

Poor heat dissipation: The air path drying tank fails.

▎Comfort in the car depends on it

● Air conditioners rely on its condensers and evaporators for cooling

Air conditioner evaporator assembly

Truck air conditioners, like household air conditioners, consist of a compressor, a condenser, and an evaporator.

Condensers and evaporators are both heat exchange equipment, but in terms of use, the condenser is used to discharge heat, and the evaporator is used to absorb heat.

The internal medium of both is a refrigerant, also known as a refrigerant (freon). When the refrigerant flows to the evaporator, the medium absorbs heat for vaporization and absorbs external heat, while when it flows to the condenser, the medium cools down and liquefies, discharging heat.

If we use the analogy of a household air conditioner, the condenser is like the outdoor unit of the air conditioner, and the evaporator is the indoor unit.

Therefore, the role of the evaporator is to refrigerate.

Refrigeration object: cab.

The purpose of refrigeration: to provide a more comfortable temperature for drivers and passengers.

Poor refrigeration: The refrigeration capacity is reduced, which affects the comfort of personnel.

● Warm the heart and warm the body: Warm air water tank

Warm air tank

Like the engine tank, the heater tank is used to dissipate heat and is generally located inside the instrument panel near the air outlet. Depending on the needs of the driver and passengers, excess heat from the engine is transferred to the cab through water circulation.

Heat dissipation object: cab.

The purpose of heat dissipation: to provide a more comfortable temperature for the driver and passengers.

Poor heat dissipation: The temperature rises slowly, which affects the comfort of personnel.

The car is a very integrated product, and thousands of parts are integrated to work together to provide us with strong power and comfort.

Whether the heat dissipation system is air-cooled or water-cooled, the ultimate purpose is to dissipate heat into the outside air, but the internal heat dissipation form is different. After reading the introduction of this article, I believe that you will not be confused when you see these radiators, evaporators, and condensers again.