A heater core is a device like a radiator used to heat a vehicle's cabin. Hot coolant from a vehicle engine is passed through a core winding tube, a heat exchanger between the cooler and the air cabin. The fins attached to the core tube serve to increase the surface for heat transfer to the air which is forced through them, by the fan, thus heating the passenger compartment.
Video Heater core
How it works
Internal combustion engines in most cars and trucks are cooled by a mixture of water and antifreeze that is circulated through the engine and radiator by a water pump to allow the radiator to release engine heat to the atmosphere. Some of the water can be diverted through the heating core to provide engine heat to the cab, or adjust the conditioned temperature.
A heater core is a small radiator located underneath the vehicle dashboard, and it consists of a conductive aluminum or brass tube with a cooling fins to increase the surface area. The heat sink that passes through the heat heater releases heat before returning to the engine coolant circuit.
The squirrel cage from the vehicle ventilation system forces air through the heating core to transfer heat from the cooler to the air of the cab, which is directed to the vehicle through vents at various points.
Maps Heater core
Control
After the engine has been warmed, the coolant is kept at a temperature more or less constant by the thermostat. The temperature of the air entering the interior of the vehicle can be controlled by using a valve that limits the amount of coolant that passes through the heating core. Another method is to close the heater core with the door, directing some (or all) air enters around the heating core completely, so it is not heated (or reheated if the AC compressor is on). Some cars use a combination of these systems.
A simpler system allows the driver to control the valve or door directly (usually by using a play button or lever). More complicated systems use a combination of electromechanical actuators and thermistors to control valves or doors to send air at the correct temperature value chosen by the user.
Cars with multiple climatic functions (allowing the driver and passengers to each set different temperatures) can use the heating core divided into two, where different amounts of coolant flow through the heater core on both sides to get the desired heating.
Air Conditioning
In cars equipped with air conditioning, outside air, or cabin air when the recirculation flap is set to close external air ducts, first forced, often after being filtered by a cabin air filter, through an air-cooled evaporator coil. This can be thought of as a heating core filled with a very cold liquid that undergoes a gas phase change (evaporation), a process that cools instead of heating the incoming air. To get the desired air inlet temperature can be cooled first by AC and then heated again by the heater core. In vehicles equipped with manual controls for heating and air-conditioning compressors, using both systems together will remove air humidity in the cabin, since evaporator coils remove moisture from the air due to condensation. This can result in increased levels of air comfort in the vehicle. The automatic temperature control system can take the best action in regulating the operation of the compressor, the amount of reheating and blower speed depending on the internal air temperature, internal and cabin temperature values ​​or the rapid defrost effects demanded by the user.
Engine cooling function
Since the heating core cools the heat sink from the engine by transferring heat to the air of the cabin, it can also act as an auxiliary radiator for the engine. If the radiator is working incorrectly, the operator may turn on the heat (along with a fully loaded cabin blower fan, and with the window open) in the passenger cabin, resulting in a certain cooling effect on the overheated engine coolant. This idea only works at a certain level, because the heating core is not large enough and also does not have enough cold air through the cooler to cool a significant amount of coolant significantly.
Possible problems
Heating core consists of small piping which has many corners. Blockage of piping may occur if the cooling system is not flushed or if the coolant does not change regularly. If a blockage occurs the heater core will not work properly. If the coolant flow is limited, the heating capacity will decrease or even disappear altogether if the heating core becomes blocked. The control valve can also clog or jam. Where a mixed door is used instead of a control valve as a method of controlling the amount of air heating, the door itself or its control mechanism may become stuck due to thermal expansion. If the climate control unit is automatic, the actuator can also fail.
Another possible problem is the leak in one of the connections to the heater core. This may be first seen by odors (ethylene glycol is widely used as a coolant and has a sweet smell); it can also cause fog (rather greasy) from the windshield over the front windshield vents. Glycols can also leak directly into the car, causing upholstery or wet carpet.
Electrolysis can cause excessive corrosion which causes the break up of the heating core. The cooler will spray directly into the passenger compartment followed by white smoke, a significant driving hazard.
Since the heater core is usually located under the dashboard inside the vehicle and is enclosed in the duct of the ventilation system, its service often requires disassembling large parts of the dashboard, which can become labor-intensive and therefore expensive.
Since the heating core depends on the heat of the coolant to warm the cabin air, it obviously will not start working until the engine coolant is warm enough. This problem can be overcome by equipping vehicles with additional heating systems, which can use electricity or burn vehicle fuel to quickly bring the engine coolant to operating temperature.
Air-cooled engine
Machines that do not have a water cooling system can not heat the cabin through the heating core; One alternative is to guide the air around the engine exhaust (very hot) and then into the interior of the vehicle. Temperature control is achieved by mixing with unheated outdoor air. Volkswagen engine air-cooled using this method. Depending on the design, this can lead to security issues where leaks in the exhaust system will start filling the passenger cabin with deadly smoke.
Reusing for other purposes
Hot car core is also used for D.I.Y. projects, such as to cool the homemade liquid cooling system for computers.
See also
- Air conditioning
- Refrigeration internal combustion engine
- Radiator (cooling machine)
- Radiator (heating)
- Water cooler
External links
- the entire cooling system
Source of the article : Wikipedia
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