1. Introduction
Why turbocharged engine will have more power than ordinary engine, wherein one of the reasons that the ventilation efficiency is higher than naturally aspirated engines in general . As the air enters the turbocharger its temperature would rise sharply, the density decreases accordingly, and the intercooler functions as the cooling air is, high temperature air is cooled through the intercooler, and then into the engine. If you let the hot air directly into the supercharged engine, the air temperature is too high because it will cause engine damage or even turn off the phenomenon of missing intercooler.
2, the role of intercooler
Function
is reduced in the intercooler of the engine intake air temperature. So why do you want to reduce the intake air temperature?
(1) the temperature of the exhaust gas discharged from the engine is very high, the heat conduction through the booster will increase the temperature of the intake air. Also, the air density increases during the compression process, which will inevitably lead to increase in temperature of air, thus affecting the charging efficiency of the engine. If you want to further improve volumetric efficiency, we must reduce the intake air temperature. Data show that the air-fuel ratio under the same conditions, the charge air temperature drops every 10 ℃, engine power can be increased by 3 to 5 percentage percentage.
(2) if uncooled charge air enters the combustion chamber, in addition to affect the charging efficiency of the engine, the engine very easily lead to excessive combustion temperatures, resulting in detonation failure, and increases in engine exhaust gases NOx content, causing air pollution.
In order to solve the adverse effects of temperature increase caused by pressurized air, thus requiring the installation of an intercooler to reduce the intake air temperature.
3, the intercooler Category
An intercooler generally made of an aluminum alloy material. According to different cooling medium, the common cold may be divided into air-cooled and water-cooled two kinds.
4, the intercooler maintenance method
a space in the cold air cooling of the heat sink fitted with a water tank, mounted in front of the engine, and by the suction fan through surface cars air cooled intercooler, if poor cooling will result in lack of engine power, fuel consumption increases, and therefore, should be regularly intercooler for inspection and maintenance, the main contents are: cleaning the exterior (on the car cleaning method)
Since the intercooler is mounted at the forefront, the intercooler fins channel often leaves, sludge (overflow of the steering hydraulic oil tank) from blocking the intercooler heat blocked, so this should be periodically cleaned at. The method of cleaning is not too high pressure gun at an angle perpendicular to the plane of the intercooler, top down or bottom flushing slow, but can not prevent damage to the intercooler SLIP. Internal cleaning, checking (dismantling the cleaning method)
intercooler internal duct often with sludge, gum and other dirt, not only the air flow path is narrowed, and the cooling heat exchange capacity decreases, for this purpose, It must also perform maintenance and cleaning. General engine overhaul or year, while welding repair tank, response intercooler internal cleaning and inspection.
Cleaning method: percentage soda aqueous solution containing 2 (the temperature should be 70-80 deg.] C) was added to the cooler, is filled, wait 15 minutes, fancy water leaks at cooler. If should carry out dismantling, repair welding (tank initiates the same); if there is no water leakage, pitching, repeated several times, the washings decanted, and then charged into an aqueous solution of soda ash percentage 2 containing rinsing clean, until relatively far cleaning, hot water cleaning-bet (80-90 deg.] C) wash, clean up until the discharged water. The external oil stained intercooler, also washed with alkaline, is: at the oil soaked in lye, clear with a brush until clean. After cleaning, the water with compressed air in the intercooler or natural dry or dry during installation is not connected to the intercooler and the intercooler pipe connected to the engine, the engine is started, until the intercooler outlet division anhydrous , connect the engine intake manifold. If inner core intercooler heavily soiled found, should be carefully examined each of the air cleaner and the intake pipe where the loopholes, and troubleshooting.
TurbochargerThe biggest problem is that the close proximity between the suction inlet and the exhaust gas temperature of the fresh air, sucked in and the temperature of the compressed fresh air is also increased a lot, so even if a mechanical impact of the hot exhaust gas does not increase compression engine intercooler also need to cool the intake air. Compressed air temperature rises, the simplest example is the air pump to inflate the tires, do not believe that friends can touch the pump is inflated, compressing the air will know how terrible accumulation of heat. In addition, we can know through chemical and physical knowledge, the higher oxygen content in the low-temperature air, one might ask:? What is the relationship of this to know that fuel combustion need is more oxygen in the air, the oxygen to make more fuel combustion, which broke out more power. Want to know more friends can refer to the related presentations in the “suction system.” An intercooler is a highly efficient radiator, the main role is, before the fresh air into the engine to cool. You can imagine, it is located prior to the cold water tank cooling, can be directly impacted cold air blowing head, but also behind the air cleaner, turbocharger or supercharger. The actual situation is indeed the case, most of the cars are equipped with a cold front located in the cooling water tank, and the cooling effect is indeed better than some of the overhead intercooler layout, however, this will affect more or less blown over heat air tanks, so that in some extreme cases, for example on the track, it is necessary to upgrade the engine to control the temperature of cooling tank.
5, the working principle
Cold good use of the design may obtain extra percentage -10 5 percent power.
There are some car using an overhead cooler, the cooling air is obtained through the hood opening, so that the car before the start, the intercooler will be blown number of blowing hot air from the engine compartment, although the heat efficiency is affected, but because the intake air temperature rises in such a case, the engine’s fuel consumption will drop a lot, which also indirectly reduce the efficiency of the engine, but for the strong power boost cars, too large power due to start but will ease instability in this case, Subaru Subaru Impreza cars is a typical overhead intercooler. In addition, the biggest advantage of the cold overhead layout is that it can also effectively shorten the stroke of the compressed air to the engine.
6, STI is not cold overhead Patent
all vehicles using turbo intercooler are good, and the original standard intercooler generally have room for improvement. Because we seek is as much of the air sucked into the engine, so the internal structure if the cold will affect the air flow, it means that the engine will lose some momentum. Intercooler two most important quality parameters are the shape of the interior air flow passage and the cooling fin design, the intercooler in the ideal state is the design area of cooling fins can be as large as possible, while the inner gas flow passages preferably stiff bent and weld marks impede gas flow does not occur. Some people think that since all of the intercooler will affect intake air flow, use an intercooler plan is not worth it in the end? If you take into account the equipment a good design affects the airflow is relatively small and of good quality intercooler available power increase, we feel that the use of the intercooler is more cost effective. Imagine if the original car’s supercharged value of 15psi, according to experts estimate, intercooler bring pressure loss in general is 0.5-0.9psi, even with the pressure loss is relatively times intercooler also brought no more than 1.3psi, but also because of the increased stress can lead to increased intake air temperature, so the lower the temperature of the intake air pressure accordingly brought loss, so do not put the intake air pressure loss are to blame intercooler design on.
For high-performance vehicles, the weight is a very important issue, and is now the case with the majority of the conversion with respect to the original cold intercooler is equipped are lighter, but also no better performance less. Generally, the larger the intercooler words, the loss of air flow inside the smaller and higher cooling efficiency, since the air flow inside the stay longer in the cold time, the better by cooling. More exaggerated approach is to install a spray nozzle to the intercooler, the cold water in the evaporation can absorb a lot of heat in the compressed gas stream, the intake air temperature is reducedThe degree of the effect is very good. General intercooler under normal circumstances can reduce the intake air temperature 35-40 degrees Celsius, which can help get the engine power increase of 5 percentage -10 percentage, but this is not absolute, but is closely related to the atmospheric temperature around – —- atmospheric temperature more than the intake air temperature is low, the cooling effect of the intercooler will be better.
7, how to choose the intercooler
For many fans, the intercooler in the front bumper hearts dream modified parts are also essential properties of a symbol, it as a general sound pressure relief valve. However, it appeared to be the same variety in the cold, in which what is learned in it? If you want to upgrade or install and what matters need to pay attention to it? These issues will be eleven you answered in this unit, interested readers may wish to read on! Why do I need to install in the cold
before the formal entry into this unit, it was the first to explain the principles about the installation of the intercooler why. Intercooler installation purposes, mainly to reduce the intake air temperature, the reader might ask: Why do we need to reduce intake air temperature? This was referred to the principle of turbocharging. The turbocharger works, simply using the engine exhaust to exhaust discharge vane impact and drive the other side of the inlet vanes, the forced air and sent to the combustion chamber, the exhaust gas temperature due to the discharge is usually up to 8,9 Baidu, the joint body of the turbine also in very high temperature state, so it will increase flow through the turbine end intake air temperature, together with the compressed air will also generate heat (as compressed air molecules distance becomes smaller, will squeezing each other, the heat generated by friction phenomenon), if it shares the high-temperature gas enters the cylinder without cooling can easily lead to engine combustion temperature is too high, then it will cause pre-ignition gasoline knocking occurs, let the engine temperature rises even more, while the volume of compressed air due to thermal expansion will significantly reduce the oxygen content, this way will reduce the boost efficiency, it can not produce some of the power output. In addition, the engine temperature is invisible killer, if not try to reduce the operating temperature, once the weather hotter environment, or the case of prolonged operation of the driving experience, it is very easy to increase the chances of engine failure, and therefore only need to install in the cold intake air temperature is reduced. Know intercoolerAfter the function, then we have to explore its structure and cooling principle why.
FIG reader are a look, this Layer Cake something similar, it is a sectional view of the intercooler, whereby the figure we can see the intercooler is mainly composed of two parts. The first part of the name of Tube, FIG i.e. the first layer, whose function is to provide a channel, receiving it through a compressed air, and therefore must be Tube confined space, it will not occur the problem of the leak pressure is so compressed, and Tube is also divided into square shape, the long oval tapered three, the difference is that the trade-off between efficiency and the cooling wind resistance. The second part of the Fin name, is commonly known as fins, generally located between two layers Tube, the Tube Sticky and close together, whose function is cooling, since when compressed hot air passes through Tube, heat will be Tube communicated to the fins through the outer wall, if at this time when the temperature of the ambient air flowing through the lower fins, the heat can be carried away by the way, to achieve the purpose of cooling the intake air temperature. Continuously via the two overlapping portions together, until the structure layer is 10 to 20, is called Core, this part is called the cold body. Further, in order to make the compressed gas from the turbine before entering the Core, and to have a buffer space of the pressure accumulator, and the air flow rate can improve the Core, Core usually on both sides, and then loaded on a part called Tank outer like the funnel-shaped type in general, also arranged on the circular Importers, easy connection silicone tube, and via the intercooler is composed of four parts. As intercooler cooling principle is generally as just mentioned, is the use of the various lateral Tube dividing the compressed air from the outside and straight in front of cold air, through the heat dissipation fins connected to the Tube, the cooling air can reach purpose, the intake air temperature closer to the ambient temperature, thus to increase heat dissipation efficiency of the intercooler, as long as the thickness and increase the area to increase the Tube number, length, and other heat-dissipating fins, can achieve this purpose. But there is so easy to do? In actual fact, because of the longer, the greater the area in the cold, the more prone to problems inlet pressure loss, and this is one of this unit focuses on the problem. Why a pressure loss
Although the bulk cooler, heat exchange problem due to prolonged cooling performance better, but the air flow rate and a slow loss of pressure occur, and further more that the turbo lagSeriously, why? This should be talking about two aspects. I believe once their own car washed readers know, let the water in the spray of water column far faster, just squeeze the water can reach the head, why is this so? That is because in the case of constant pressure, flow rate per unit time will not change the size of the diameter, so as to achieve this goal, as long as the reduced diameter, flow naturally faster, increasing the diameter of a reverse flow rate on It will slow down, and this situation also occurs in the entire intake line inside. Because when the air intake passage from the original receiving a small space, a large space when passing through the intercooler, a phenomenon will have a slow flow rate, and this problem for small wind turbines with a large amount especially in the cold serious, this way will become even more serious turbo lag.
Further, when Tube air from the inlet line into the intercooler, the conversion factor will be split tapered large diameter, flow resistance is generated, resulting in a certain degree of pressure loss, plus many intercooler to increase cooling efficiency, the fins are provided (not necessarily hollow Tube), this also has the air resistance, the two together, turbo lag problem will be more apparent in the relatively inside Tube. It is worth mentioning that, the above-mentioned pressure loss, do not mean reducing the boost value is, since the intake line is closed, so that the relief operation of the wastegate, required to achieve a certain set of pressurized owners value will be, therefore constant value is not reduced, but will extend the time of arrival (as part of the pressure is consumed) and the effects of pressor response, but this is the biggest impact pressure losses. Since the installation of intercooler turbo lag will be more obvious, but they can not dress, so how to balance cooling efficiency and pressure maintenance, modifications have become the most important issue in the cooler. Difficult modified intercooler
Performance of an emphasis in the cold, in addition to have a good cooling capability, reducing the pressure loss must also be considered in, but to suppress the pressure loss and enhance the cooling efficiency, the technique is completely Instead, such a volume of the same size in the cold, heat completely if the starting point for the design, which would need to be made finer Tube and the number of fins increases, so will increase the air resistance; but if the pressure level is maintained to begin, it’s also bold Tube and reduce the fins, the heat exchange efficiency of the contrast will be poor, so the intercooler modification not as simple as we think. Therefore, methods to take into account the cooling efficiency and maintain the pressure, and most will be in two parts from the Tube and finTo begin. Tube first part, which is divided into two ways: Firstly, the use of very thin wall diameter but thicker pattern, a thick diameter to increase the smoothness of the air flow, using a thin wall and improve heat dissipation characteristics . Second: Tube diameter thick, the additional fin is provided inside the way, the hot air to increase the contact area of the metal sheet to increase the amount of heat conveyed, natural heat dissipation efficiency can be increased, but this design is often used in the cooler or high competitive car’s supercharged vehicles, so that they will not have much of hysteresis.
Next is the fin part of the general type intercooler fins, generally like Figure II, which is typically linear stripe shape without any openings, and the width of the intercooler long, there is more fins long, but since the entire fin intercooler, the cooling function play a major role, so long as it increases the area of contact with the cold air can increase the heat exchange power, the intercooler fins many were later switched in Figure III, the design of various forms, among which the wavy fin design or known as the most popular blinds. But it is the heat efficiency, or to overlap in Figure IV-called cooling fins for the best, but also the drag forces generated by the most obvious, it is more common in the Japanese D1 competition car, because the vehicle speed is not fast these games, but it needs good cooling effect to protect the high rotational speed of the engine to walk. Be modified intercooler
8 to turbine on the capacity of
After the modified theory intercooler Moving on, then we take a look, you have to observe when there is actual conversion What. In general, with the conversion into the intercooler mostly original exchange type, and the need to dramatically change the configuration of a large capacity set tubing. Direct switched original specifications and similar, only difference of different internal design of the fin and Tube thickness is slightly widened, this kit is suitable vehicle original unmodified, modified or not the amplitude of the case, original engine can potential aroused. As large capacity intercoolers, in addition to increasing the frontal area of the heat dissipation than strengthening, but will increase the thickness to ensure a constant temperature, to produce the TAS intercooler example, the general type of about 5.5 to 7.5 centimeters (for 1.6 to 2.0 liters vehicles), to strengthenType of about 8-105 cm (Suitable vehicles than 2.5 liter), also coupled with the use of a large funnel-shaped Tank accumulator, so that the air flow resistance can be reduced to a minimum by, of course, to use an enhanced intercooler where , appears in large turbine configuration is more applicable when, for example, less engine turbine No. 6, is not recommended because such a situation would be more serious lag is not conducive to low pressure response, but in NA changed Turbo vehicle inside, intercooler or bigger is better, because the cooling efficiency of the original design may not be enough, even if another low boost setting also can not be omitted in the cold, after all, a lower intake air temperature, not only can prolong engine durability, for stable power output is also helpful.
On the other hand, in the cold, except that air cooling, there are water-cooled Shape, 3S-GTE Toyota Ming machine is an example, its main advantage is its Cooler is located just before the throttle body, and therefore the intake line has a very short response characteristic high, coupled with a constant temperature of the water itself is very high, the intake air temperature constancy is also a great help, especially when there is no more obvious effects of wind hit the front, such as a traffic jam. However, since it requires another special water pump connected to the exhaust heat and the water tank, and the cooling rate is better to direct air-cooling is far greater, and therefore is still in the air-cooled intercooler mainstream. Configuration intake line
9, in a straight line into the primary
As for the mounting position of the intercooler, generally divided into front-facing and the two, of course, on the point of view of heat dissipation front first security bit is more excellent in the rod, but deals with reactive, then mounted on the case than to take advantage of, this is a short conduit which brings charged direct effects, such as short lead Impreza WRCar intercooler piping, put the throttle to reduce the pressure due to the inverted long lines caused by wear and tear, is not difficult to imagine the intake line of the overall mix, is also the focus has to be aware of when modified intercooler. Therefore, when the outer installation or upgrade intercooler, the intercooler to be noted that in addition to the size, minimize the length of the short line, and drawn to reduce the bend of a straight line, point welding, are a method of increasing the air flow rate because if there are too many knuckle joints and then smooth the airflow will send to poorHealth pressure loss phenomenon.
Second, as noted earlier intercooler On principle, the intercooler Tube too small and easy to increase the impact resistance to the reaction, and the temperature in the tube wall will be higher, the intake Similarly diameter slightly thickened also a good way As for matching the diameter size, mainly depends on the turbine outlet and the throttle valve aperture may be. It is worth mentioning that the diameter of the inlet and outlet pipeline before and after the intercooler, the diameter of the outlet should be more than 10 percentage crude front of the entrance, due to the larger diameter of the outlet, allowing the Core cooling air to faster speed through the intercooler for increased flow rate, can have a positive help. Again on the material of the intercooler section, usually made of aluminum alloy are used, not only to increase the aesthetic appearance rich texture, but also because of the high thermal conductivity of aluminum to increase the cooling effect, additional advantages of lightweight, aluminum alloy is selected one of the main reasons. As the rubber between the metal pipe connection pipe, we recommend using three or five as silicone rubber-coated products, such excellent ductility silicone tube, high temperature, high pressure and does not harden, the small vacuum tube, to the pipe, as large as the overall intake line is a very good substitute for the original, quite suitable for use in a turbine engine heat, plus the width of the clamp-type fixing ring stainless steel beam, or leakage can be avoided squib the problem arises, and is different from the original black, fighting for breath lift the vehicle, there is a great help, so before we can make the car owners assured control.
10, on the home front or good
believe that many car owners upgrade turbo Impreza, has produced good I do not know follow the set design on the original plus a large intercooler, or directly use front preferably it? To resolve this issue will need to upgrade the number of turbine numbers to decide. Since boxer engine exhaust header, as compared to longer appear straight engines, so that the low pressure response associated relatively slow, so the original design will be mounted in the cold to reduce turbo lag problem, if the upgrade the number does not exceed the number of turbine VI, displacement of 2.2 liters or more yet to come, I do not recommend using the front-mounted intercooler, because the longer the pipeline and increase the intercooler will make the problem more severe retardation, but when you meet these conditions, might considerFront cold air switch, mounted on the one hand because the cooling efficiency of the intercooler is not enough to use, partly because a large amount of air supplied more turbine flow faster, the influence brought to the elongate conduit It can be minimized, and therefore it would be more suitable for use in front-cooler.