JP2008528857A - Engine after cooling system - Google Patents

Abstract

The engine aftercooling system (10) includes a liquid-to-air aftercooler (11) and an aftercooler (11) for cooling the compressed air discharged from the compressor and used for combustion in the internal heat engine. The radiator (19) that cools the discharged coolant, the pump (21) that continuously feeds the coolant in the system (10), and the temperature of the compressed air cooled by the aftercooler (11) are detected. The outlet air temperature sensor (27), the coolant temperature sensor that detects the temperature of the coolant discharged from the aftercooler (11), and the system (10) flow according to the detected air temperature and coolant temperature. It has a controller (26) for controlling the flow rate of the coolant.

Description

  The present invention relates generally to cooling systems. More specifically, an engine aftercooling system that cools compressed air discharged from a compressor such as a turbocharger or a supercharger (or supercharger) and used for combustion in an internal heat engine (or internal heat engine). (Engine after-cooling system)

  Diesel engines often include a compressor (or compressor), such as a turbocharger or a searcher, that is mixed with diesel fuel and compresses the inlet air before it is subjected to combustion. By compressing the inlet air, more diesel fuel can be burned during each cycle of the diesel engine, resulting in an increase in engine output energy.

  The energy output and fuel consumption of many modern diesel engines are computer controlled to meet emission requirements. Therefore, this type of engine is often referred to as an “emission-controlled engine”. As the ambient temperature around the diesel engine increases, thereby increasing the temperature of the engine inlet air, the controller will automatically reduce the engine output level so that the engine energy output decreases. Note that as the temperature of the inlet air increases, the compressed air discharged from the compressor expands and thins, resulting in a decrease in the amount of diesel that can be efficiently burned per unit volume of air. Go down. This means that less diesel and air will burn during each combustion cycle of the engine, reducing engine output energy. Decreasing the engine output level reduces the amount of pollutants emitted from the engine, but significantly reduces the engine energy output (especially under heavy load conditions).

  The temperature of the compressed inlet air of a diesel engine does not depend solely on the ambient air temperature surrounding the engine. When the inlet air is compressed with a compressor such as a turbocharger or a searcher, such compression increases the temperature of the inlet air considerably. In modern diesel engines where the power level can be reduced by a computer management system built into the engine, the increase in inlet air temperature associated with compression reduces the engine power level and reduces the energy produced by the engine. End up.

  When diesel engines that rely on compressed inlet air are used in automotive and stationary mechanical applications, the diesel engine is typically provided with an after-cooling system. Such an aftercooling system can cool the compressed inlet air, thereby improving engine performance. The aftercooling system includes an “air-to-air after-cooler”. Such an air-cooled aftercooler has a design similar to a conventional “water-to-air radiator”, a plurality of cooling tubes through which compressed inlet air passes, and such cooling. A cooling fin is disposed adjacent to the tube so that heat from the compressed inlet air is transferred through the cooling fin to the air flow around the cooling fin. In automotive applications and stationary machine applications, an “air-to-air aftercooler” is usually placed against the front of a water-cooled radiator that is usually placed in front of the engine.

  Aftercooling systems, including “air-to-air aftercoolers”, are efficient in terms of cooling the compressed inlet air and increasing engine performance, but when the ambient air temperature increases, the “air-to-air aftercooler” The cooling efficiency of the “cooler” is reduced. Decreasing the cooling efficiency of the “air-to-air aftercooler” increases the temperature of the compressed inlet air discharged from the aftercooler, which reduces engine performance and reduces the computer management system built into the engine. In order to meet the emission requirements and emission regulations, the energy output level of the engine is automatically lowered as the cooling efficiency decreases.

  The decrease in the cooling efficiency of the “air-to-air aftercooler” accompanying an increase in the outside air temperature can be solved to some extent by increasing the size of the aftercooler. This is because if the size of the aftercooler is increased, more cooling is performed so as to at least partially offset the increase in ambient air temperature. In reality, however, there is a limit to increasing the size of the “air-to-air aftercooler”. For example, the size of an “air-to-air aftercooler” is limited by the size of the space in which such an aftercooler can be stored.

  If a “water-to-air aftercooler” is used instead of an “air-to-air aftercooler” to condense compressed air, the efficiency of the aftercooling system is significantly increased. The “water-to-air aftercooler” is used in marine diesel engines, and seawater is used instead of air for cooling the aftercooler. In such marine aftercooling systems, the same seawater does not flow continuously through the aftercooler, but always fresh seawater flows continuously through the aftercooler and heat exchanger. When a marine engine uses a seawater-cooled aftercooling system (that is, an aftercooling system that cools using seawater) instead of an air-cooled aftercooling system, the output energy increases.

  Aftercooling systems that use seawater for cooling are clearly not suitable for use on land engines. Although attempts have been made to improve the existing “water-to-air cooling system” for use as a land engine, there are no particularly successful examples as far as the inventors of the present application know.

  An example of a prior art “water-to-air aftercooling system” is disclosed in US Pat. No. 4,697,551 (Larsen et al.). U.S. Pat. No. 4,697,551 discloses a method and apparatus for quickly adjusting the coolant flow in a cooling system having a low coolant flow rate. By adjusting the coolant flow quickly, the air temperature after passing after-cooling can be maintained at a desired temperature, and the engine block temperature can be kept within a predetermined range at various engine loads and ambient temperatures. You can hold it. In particular, US Pat. No. 4,697,551 discloses a shuttle valve as a fast acting proportional valve and a fast acting shuttle valve for an aftercooler, which is a “high temperature obtained from the radiator inlet. "Cooling liquid" and "cooled liquid obtained from the outlet of the radiator and used for the aftercooler" are used for mixing. The shuttle valve for the aftercooler is used for mixing the “cooled coolant obtained from the outlet of the radiator” and the “coolant obtained from the aftercooler and used for the engine block”. . The operation of the shuttle valve for the radiator is controlled by a valve drive controller, and is controlled according to the temperature of the air discharged from the aftercooler (the temperature measured by the air temperature sensor). The operation of the shuttle valve for the aftercooler is controlled by a valve drive controller, and is controlled according to the temperature of the coolant in the engine block. A pump is used so that the coolant flows through the radiator, the aftercooler, and the engine block.

  Another example of a prior art “water-to-air aftercooler” is disclosed in US Pat. No. 5,201,285 (McTaggart). US Pat. No. 5,201,285 discloses a controllable cooling system for an internal heat engine equipped with a turbocharger. The cooling system includes a heat exchange radiator, a liquid coolant that absorbs heat from the engine, a pump that circulates the coolant, a fan for forcing air into a heat exchanger with an engine coolant radiator, and air It has a separate radiator for the included aftercooler coolant. A cooling turbocharger system for an engine includes a temperature control valve, which directs a portion of the liquid coolant discharged from the engine to the radiator and the liquid coolant after being discharged from the engine. Depending on the temperature, part of the liquid coolant leads to bypass the engine. In the liquid subcooler heat exchanger, the temperature of the liquid coolant is lowered by passing it through a heat exchanger in which air is forcibly sent by a fan. A part of the liquid coolant discharged from the radiator is guided to the subcooler heat exchanger by the flow control valve, and a part of the liquid coolant is guided to the engine. In the aftercooler heat exchanger, the temperature of the combustion air discharged from the turbo compressor is lowered by passing the heat exchanger through which the liquid coolant obtained from the liquid subcooler heat exchanger flows.

  Yet another example of the prior art “water-to-air aftercooling system” is disclosed in US Pat. No. 4,977,862 (Aihara et al.). U.S. Pat. No. 4,977,862 discloses an engine room cooling control system for an engine including an aftercooling system. The aftercooling system includes a “liquid-to-air aftercooler” or intercooler that cools the compressed gas discharged from the compressor (compressor in the form of a turbocharger) and used for combustion in the engine . The disclosed after-cooling system includes a radiator for cooling the liquid coolant discharged from the after-cooler, a pump for sending the coolant to flow through the system, and the temperature of the compressed air cooled by the after-cooler. Air temperature sensor to detect the coolant, coolant temperature sensor to detect the temperature of the coolant discharged from the aftercooler, and controller to control the flow rate of the coolant flowing through the system according to the detected air temperature and coolant temperature. is doing. The disclosed cooling circuit not only cools the aftercooler, but also cools the compressor.

  The aftercooling system disclosed in US Pat. No. 4,977,862 has several disadvantages. The most notable drawback is that the system controller can stop the pump from supplying coolant to the aftercooler. If the coolant flow through the aftercooler stops, the aftercooler itself will be damaged. The inlets and outlets of the aftercooler assembly of such aftercooling systems include vents or ducts so that the pressurized air at the inlet side of the aftercooler is distributed to the larger inner surface of the core of the aftercooler. It will be. There is a hot-spot where the compressed air collides with the center of the first aftercooler core. If the coolant does not move through the core, heat cannot be removed from the central area where hot air impinges. Thus, the center area | region which cannot remove heat becomes large with a heating. Since the structure around the aftercooler core is not affected by such hot spots, the coolant does not flow, and the aftercooler core is buckled and structurally broken. Once such a phenomenon occurs, the coolant reaches the boiling point due to air, so that the cooling capacity is lost, and the performance of the coolant pump necessary for normal operation is greatly reduced. Since air is trapped in the system on the suction side of the pump, the coolant flow will be adversely affected.

  Therefore, a “water-to-air aftercooling system” suitable for use in land engines such as land diesel engines is desirable.

  The object of the present invention is to eliminate or at least reduce one or more of the disadvantages of the prior art described above, or to provide a useful or commercially preferred option.

  Other objects and advantages of the present invention will become apparent from the following description with reference to the drawings. Note that this description shows a preferred embodiment of the present invention, and is merely an example.

As a first aspect, the present invention provides an engine aftercooling system. Such an engine aftercooling system is
Liquid-to-air after-cooler for cooling the compressed air (or compressed air) that is discharged from the compressor and used to burn in the internal heat engine (or internal heat engine) cooler),
A radiator for cooling the coolant discharged from the aftercooler,
A pump for continuously feeding the coolant in the system;
Outlet air temperature sensor for detecting the temperature of the compressed air cooled by the aftercooler,
A coolant temperature sensor for detecting the temperature of the coolant discharged from the aftercooler, and a controller for controlling the flow rate of the coolant flowing through the system according to the detected air temperature and coolant temperature. .

  The aftercooling system can be used with any suitable internal heat engine. Such a suitable internal heat engine may or may not be an “emission control engine capable of lowering the output level”. Moreover, this internal heat engine may be attached to the vehicle or may not be attached. However, the aftercooling system is preferably used in conjunction with an “emission control engine capable of lowering the output level” such as “an emission control diesel engine capable of lowering the output level”.

   Emission control engine that can reduce the output level by the engine after cooling system (for example, “emission control diesel engine that can reduce the output level” using the after cooling system) has a relatively high external environment. Even temperature is maintained without lowering the high power level. The aftercooling system also reduces the combustion consumption of such engines.

  The aftercooling system should be used in conjunction with a suitable internal heat engine (eg, an internal heat engine powered by diesel, gasoline or gas) with an appropriate compressor (eg, a compressor such as a turbocharger or supercharger) Can do. The inlet air is compressed by a compressor before being burned by the internal heat engine.

  The aftercooling system of the present invention has better performance than other engine aftercooling systems of similar size. For this reason, the aftercooling system of the present invention is particularly suitable for use in a situation where a space capable of accommodating the engine aftercooling system is important.

  Preferably, the aftercooling system is independent of other cooling systems such as engine cooling systems.

  The “liquid-to-air aftercooler” of the engine aftercooling system may be of any suitable type. In a preferred embodiment, the liquid-to-air aftercooler comprises a pipe through which the “compressed inlet air” discharged from the compressor passes, and a plurality of cooling tubes arranged adjacent to the pipe. . Heat will be transferred from the compressed inlet air to the coolant flowing through the cooling tube. In a particularly preferred embodiment, the liquid-to-air aftercooler includes three cooling sections, each including a plurality of cooling tubes. Each of the cooling sections has an inlet port and an outlet port.

  In an engine aftercooling system, a suitable liquid-to-air cooling radiator may be used. For example, a liquid-to-air cooling radiator may be used that includes several vertically extending cooling tubes. In a preferred embodiment, for high temperature and / or high load applications, it is particularly useful for the radiator to be a triple-pass radiator with three sections each containing a plurality of horizontal cooling tubes. is there.

  Preferably, the cooling tube of the first section extends from the inlet port of the radiator. Therefore, the cooling liquid can flow into the cooling tube of the first section through the inlet port. The cooling tube of the second section is preferably located below the first section. Preferably, the cooling tube of the second section is connected to the inlet port on the side opposite to the side where the first section is provided. Therefore, the cooling liquid can flow from the cooling tube of the first section to the cooling tube of the second section in a direction opposite to the flow of the cooling liquid through the cooling tube of the first section. The cooling tube of the third section is preferably located below the second section. Preferably, the cooling tube of the third section is connected to the second section end opposite to the second section end to which the first section is connected. Therefore, the cooling liquid can flow from the cooling tube of the second section to the cooling tube of the third section in a direction opposite to the flow of the cooling liquid through the cooling tube of the second section. Preferably, the “end of the third section cooling tube” on the side to which the second section cooling tube is not connected is connected to the outlet of the radiator, so that the coolant is cooled in the third section. Can flow from the tube through the outlet. It has been found that a radiator with a horizontally extending cooling tube can cool the "coolant flowing through the radiator" more efficiently than a radiator with a vertical cooling tube, so the radiator It is preferred to have a cooling tube that extends horizontally. It should be noted that an undesired “high temperature range” or “hot spot” is unlikely to occur in a radiator having a horizontally extending cooling tube. The radiator may be any suitable size and shape and may be formed from any suitable material.

  Preferably, the plurality of vertical cooling fins are arranged adjacent to the cooling tubes of the various sections of the radiator. Therefore, heat is transferred from the cooling liquid in the cooling tube to the cooling fin, and then transferred to the air passing through the cooling fin.

  Preferably, the radiator has a header tank on its side. The radiator preferably includes a plurality of baffle plates in a header tank. Such baffle plates direct the coolant to flow to the various sections of the radiator.

  Preferably, the radiator is formed from an aluminum alloy.

  The radiator and the aftercooler are preferably similar to each other.

  The pump can be of any suitable type. For example, the pump may be a variable flow pump or a constant flow pump. In the case where the pump is a variable flow rate pump, for example, a volume transfer type blade pump may be used. In a particularly preferable aspect, the flow rate of the pump may be a flow rate at which the coolant amount per minute is 1 to 250 L or 30 to 180 L. When the pump is a constant flow rate pump, for example, a centrifugal pump may be used. Preferably, the pump is driven by a hydraulic motor (or hydraulic motor) or an electric motor, and may be either a pump that can change the pump flow rate or a pump that cannot change the pump flow rate.

  While the engine is running, it is preferred that the pump continuously delivers coolant into the engine aftercooling system. Particularly preferably, the coolant is continuously fed into the engine aftercooling system by the pump only while the engine is running.

  Preferably, an inlet air temperature sensor that detects the temperature of the compressed air before being cooled by the aftercooler is provided. The inlet temperature sensor may be an air temperature sensor suitable for detecting the temperature of the compressed air before being cooled by the aftercooler. In a preferred embodiment, the inlet air temperature sensor has the form of an air temperature probe. The inlet air temperature sensor may be a remote sensor such as an infrared sensor. The inlet air temperature sensor is preferably arranged adjacent to the inlet of the aftercooler into which the compressed air is introduced.

  The outlet air temperature sensor may be an air temperature sensor suitable for detecting the temperature of the compressed air cooled by the aftercooler. Preferably, the outlet air temperature sensor has the form of an air temperature probe. The outlet air temperature sensor may be a remote sensor such as an infrared sensor. The outlet air temperature sensor is preferably arranged adjacent to the “aftercooler outlet” from which the cooled compressed air is discharged.

  The coolant temperature sensor may be any type of temperature sensor suitable for detecting the temperature of the coolant discharged from the aftercooler. In a preferred embodiment, the coolant temperature sensor has the form of a water temperature probe. The coolant temperature sensor may be a remote sensor such as an infrared sensor.

  The controller is any controller that is suitable for controlling the flow rate of the coolant flowing through the system according to the air temperature and coolant temperature detected by the air temperature sensor and coolant temperature sensor. It doesn't matter. A preferred embodiment includes a hydraulic controller or electronic controller that controls the speed of the pump, and programmable logic for controlling the hydraulic controller or electronic controller in response to the sensed air temperature and coolant temperature. A controller (PLC) is included.

  By the controller, the flow rate of the coolant flowing through the system can be controlled in an appropriate manner. Preferably, the controller controls the flow rate of the cooling liquid fed through the system by the pump, that is, the flow rate of the pump. In another preferred embodiment, the controller does not control the coolant flowing through the system by controlling the pump flow rate. For example, the pump may be a constant flow rate pump that continuously delivers coolant to flow through the system at a constant rate, and the system includes one or more bleed valves that can be controlled by a controller. It may be a thing. If the system includes a bleed valve, the amount of the coolant flowing through the system can be increased or decreased, so that the coolant flowing through the system can be controlled.

  Preferably, the pump sends the cooling liquid cooled by the radiator from the radiator to the aftercooler.

  Preferably, the aftercooling system includes an ambient air temperature sensor that senses the temperature of the ambient air present near the periphery of the system. The ambient air temperature sensor may be any type of air temperature sensor that is suitable for sensing the temperature of the air present around the aftercooling system. In a preferred embodiment, the ambient air temperature sensor has the form of an air temperature probe. The outside air temperature sensor may be a remote sensor such as an infrared sensor. The ambient air temperature sensor is preferably located adjacent to the aftercooling system.

  The aftercooling system preferably includes a fan that forces air to the radiator. When a fan is provided in the aftercooling system, the radiator is assisted in cooling the coolant that passes through the radiator. The fan may be any type of fan, for example, a variable speed fan or a constant speed fan. In addition, the fan which can change the rotation direction of a fan is preferable. Preferably, the controller can control the speed (or rotational speed) of the fan or the direction of rotation of the fan.

In a preferred embodiment, the ambient air temperature sensed by the ambient air temperature sensor and the “compressor (eg turbocharger or supercharger) sensed by the inlet temperature sensor and fed to an aftercooler where cooling or condensation takes place The controller determines the difference from the "compressed air temperature". In a preferred embodiment, the controller determines the difference between the outside air temperature detected by the outside air temperature sensor and the “temperature of the compressed air discharged from the aftercooler” detected by the outlet air temperature sensor. Further, in a preferred embodiment, to determine the coolant flow rate (ie, the flow rate of the coolant flowing through the system) and the fan speed at which the coolant temperature and the temperature of the compressed air discharged from the aftercooler are maintained at the optimum temperature. And the controller
The difference between the ambient air temperature and the temperature of the compressed inlet air before being cooled by the aftercooler,
The difference between the ambient air temperature and the temperature of the compressed inlet air discharged from the aftercooler, and the coolant temperature detected by the coolant temperature sensor are used.

  Preferably, due to the speed of the fan, the controller controls the fan so that the compressed inlet air discharged from the aftercooler is maintained at an optimum temperature by the coolant temperature. Preferably, due to the coolant flow rate, the controller causes the coolant flow rate through the system by the pump (i.e., the pump flow rate) so that the compressed inlet air discharged from the aftercooler is maintained at an optimum temperature. The flow rate).

  The optimum temperature may be any suitable temperature. When the engine is an “engine capable of lowering the output level”, the optimum temperature of the compressed inlet air discharged from the aftercooler is the temperature at which the output level of the engine is prevented from decreasing or the amount of decrease in the engine output level It is preferable that the temperature be a minimum.

  Preferably, the aftercooling system includes a manifold tank. The manifold tank may be any suitable size and shape and may be formed from any suitable material. The manifold tank is preferably connected to the outlet of the pump and the inlet of the aftercooler.

  Preferably, the aftercooling system includes a header tank. The header tank may be any suitable size and shape and may be formed from any suitable material. The header tank is preferably connected to the manifold tank.

  The aftercooling system preferably includes a coolant level sensor. The coolant level sensor may be any suitable type of sensor. In a preferred embodiment, the coolant level sensor detects the coolant level (or coolant level) of the header tank.

  Preferably, the aftercooling system includes an auxiliary tank (or expansion tank). The auxiliary tank may be any suitable size and shape and may be formed from any suitable material. The auxiliary tank is preferably connected to the header tank.

  The aftercooling system with the thermal circuit including the aftercooler, radiator, pump and "pipe or conduit connecting the various elements" may be made of any suitable material. In a preferred form, the thermal circuit is made of aluminum or an aluminum alloy. Since aluminum and aluminum alloys have excellent thermal conductivity, temperature changes in the system 10 can be detected relatively quickly by the controller, and the controller can quickly respond to the detected temperature changes. As a result, the controller can efficiently control the system in real time.

  A preferred embodiment of the present invention will be described with reference to FIG. This will allow a better understanding of the present invention and practice of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

  FIG. 1 schematically illustrates a preferred embodiment of an engine aftercooling system 10 of the present invention suitable for use in an “emission controlled diesel engine capable of lowering power levels”.

  The engine aftercooling system 10 includes a “liquid-to-air aftercooler 11” that cools compressed air discharged from a compressor such as a turbocharger or a supercharger and used for combustion in an internal heat engine. . The aftercooler 11 includes a pipe 12 connected to the outlet of a compressor (eg, turbocharger or supercharger). Therefore, the compressed inlet air discharged from the compressor passes through the pipe 12. The aftercooler 11 has a plurality of sections 13 each having a plurality of cooling tubes. Since such a section 13 is arranged adjacent to the pipe 12, the heat of the compressed air passing through the pipe 12 is transferred to the cooling liquid (for example, water) passing through the plurality of tubes of each section 13. become. Section 13 has an inlet port 14 and an outlet port 15 respectively. Therefore, after the coolant flows into each section 13 via each inlet port 14, it is discharged from each section 13 via each outlet port 15.

  Each inlet port 14 of the aftercooler 11 is connected to a manifold tank 16. Therefore, the coolant flowing out from the manifold tank 16 flows to the section 13 through the inlet port 14.

  Each outlet port 15 of the aftercooler 11 is connected to a coolant temperature sensor 17. As a result, the coolant flowing out from the section 13 via the outlet port 15 passes through the coolant temperature sensor 17, so that the temperature of the coolant is detected.

  The water temperature sensor 17 is connected to the inlet port 18 of the radiator 19. Therefore, the coolant that has passed through the temperature sensor 17 flows into the radiator core via the inlet port 18. The radiator 19 is a triple pass radiator with a horizontal cooling tube and an outlet port 20. An inlet port 18 is provided at the top of the radiator 19, and an outlet port 20 is provided diagonally opposite the inlet port 18. The coolant flowing into the radiator 19 through the inlet port 18 flows through the horizontal cooling tube of the radiator 19. Accordingly, the heat of the cooling liquid is transferred to the air around the horizontal cooling tube, so that the heat is removed from the cooling liquid. The “cooled coolant” is discharged from the radiator 19 through the outlet port 19 at the bottom of the radiator 19.

  The outlet port 20 of the radiator 19 is connected to an inlet port of a coolant pump 21 driven by a hydraulic motor or an electric motor 22. The pump 21 is a pump capable of continuously feeding 1 to 250 L or 30 to 180 L of coolant per minute. The outlet port of the pump 21 is connected to the manifold tank 16, and the manifold tank 16 and the header tank 23 are connected to each other. Accordingly, the coolant discharged from the outlet port of the pump 21 is stored in the manifold tank 16 and the header tank 23.

  The header tank 23 is disposed adjacent to an auxiliary tank (expansion tank) 24. The coolant level sensor 25 detects the coolant level (liquid level) inside the header tank 23 for the management system. The coolant circulating in the engine aftercooling system 10 is supplied from the header 23 and the auxiliary tank 24.

  The radiator 19 is provided with a variable speed fan 30 that can forcibly send air to the radiator core. Therefore, heat is transferred from “the cooling liquid passing through the radiator 19” to “the air that is forcibly sent to the radiator 19 by the fan 30”, so that the cooling liquid is cooled.

  "Coolant temperature detected by coolant temperature sensor 17", "Temperature of compressed inlet air discharged from aftercooler 11" detected by outlet air temperature sensor 27, "Detected by inlet air temperature sensor 28" The controller 26 controls the speed of the hydraulic motor 22 in accordance with “the temperature of the compressed inlet air before being cooled by the aftercooler 11” and “the ambient air temperature detected by the ambient air temperature sensor 29”. Thereby, the flow rate of the pump 21 is controlled. In particular, the controller 26 controls the speed of the pump 21 that feeds the coolant flowing in the system 10 according to the detected coolant temperature and air temperature (that is, the flow rate of the pump 21). The temperature of the “cooled compressed inlet air” discharged from the can be maintained at an optimum temperature. The optimum temperature of the compressed air discharged from the aftercooler 11 is, for example, a temperature that can prevent a decrease in the engine output level, or a temperature that can minimize the amount of decrease in the engine output level.

  The controller 26 includes a programmable logic controller (PLC) or computer and a hydraulic controller or electronic controller. The output sides of the coolant temperature sensor 17 and the air temperature sensors 27 to 29 are connected to the input side of the PLC or computer. In the PLC or the computer, the air temperature and the coolant temperature detected by the sensors 17 and 27 to 29 are processed, and a control signal for controlling the hydraulic pressure controller or the electronic controller is output. As part of the processing of the “engine inlet air temperature” and “coolant temperature” detected by sensors 17 and 27-29, the PLC or computer may detect the ambient air temperature detected by air temperature sensor 29 and the air temperature sensor. The difference from the “inlet air temperature sent to the aftercooler 11” detected by 28 is calculated. Further, the PLC or the computer calculates a difference between the outside air temperature detected by the inlet air temperature sensor 29 and the “temperature of the outlet air discharged from the aftercooler 11” detected by the inlet air temperature sensor 27. The PLC or the computer uses the temperature difference and the coolant temperature sensor 17 so that the compressed inlet air discharged from the aftercooler 11 is maintained at or near the optimum temperature and the flow rate of the pump 21 and the speed of the fan 30. Is determined. Since the PLC or computer outputs a control signal to the hydraulic controller or electronic controller of the fan 30 and the pump 21, the flow rate of the pump 21 and the speed of the fan 30 are maintained at values calculated by the PLC or the computer. . In particular, the hydraulic controller or electronic controller controls the speed of the hydraulic motor or electric motor 22 in accordance with the flow rate control signal from the PLC or computer, so that the flow rate of the pump 21 becomes a value calculated by the PLC or computer. Maintained (and therefore the flow rate of the coolant flowing through the system 10 is maintained as well).

  The PLC or computer can control not only the speed of the fan 30 but also the direction of rotation of the fan 30. The rotation direction of the fan 30 is determined by a parameter set by the PLC of the controller 26 or a computer.

  All elements of the thermal circuit, including the aftercooler 11, the radiator 19, the pump 21, and the "pipe connecting the various elements" are made of aluminum or an aluminum alloy. Due to the excellent thermal conductivity of aluminum or aluminum alloy, temperature changes in the system 10 can be detected relatively quickly by the controller 26, so that the controller 26 can respond quickly to detected temperature changes. As a result, the system 10 is efficiently controlled by the controller 26 in real time.

  Unless stated otherwise in the specification, the expressions “comprising” or “comprising” as used in the claims and specification refer to other elements in addition to the elements referred to. Is also meant to include or include.

  Further, unless stated otherwise in this specification, the expressions “substantially” or “about” used in the claims and the specification are not limited only to the numerical values defined thereby. Means.

  It should be understood that modifications and changes can be made to the present invention by those skilled in the art without departing from the scope or concept of the invention. It should be noted that modifications and changes apparent to those skilled in the art are within the scope defined by the claims or equivalents thereof.

  If a prior art publication is mentioned in this specification, that reference shall not acknowledge that the publication forms part of the common general knowledge of the field in Australia or other countries. Will be clearly understood.

FIG. 1 schematically illustrates a preferred embodiment of an engine aftercooling system 10 of the present invention.

Claims (19)

An engine aftercooling system,
Liquid-to-air aftercooler for cooling the compressed air discharged from the compressor and used for combustion in the internal heat engine,
A radiator for cooling the coolant discharged from the aftercooler,
A pump for continuously feeding the coolant in the system;
Outlet air temperature sensor for detecting the temperature of the compressed air cooled by the aftercooler,
A coolant temperature sensor for detecting the temperature of the coolant discharged from the aftercooler, and a controller for controlling the flow rate of the coolant flowing through the system according to the detected air temperature and coolant temperature. Engine after-cooling system. The liquid-to-air aftercooler is
The engine aftercooling system according to claim 1, comprising a pipe through which compressed inlet air obtained from a compressor passes, and a plurality of cooling sections disposed adjacent to the pipe.   The engine aftercooling system according to claim 1, wherein the radiator is a triple pass radiator.   The engine aftercooling system of claim 1, wherein the pump is a variable flow rate pump.   The engine aftercooling system of claim 1, wherein the pump comprises a hydraulic motor or an electric motor.   6. An engine aftercooling system according to claim 5, wherein the speed of the hydraulic or electric motor can be varied.   The engine aftercooling system of claim 1, wherein the pump operates continuously while the engine is operating.   The engine aftercooling system of claim 1, further comprising an inlet air temperature sensor that senses the temperature of the compressed air before it is cooled by the aftercooler.   The engine aftercooling system of claim 1, wherein the controller includes a hydraulic controller or an electronic controller that controls the flow rate of the pump.   The engine aftercooling system according to claim 1, wherein the controller controls a flow rate of the coolant flowing in the system by controlling a speed of a coolant sent in the system by a pump. .   The engine aftercooling system according to claim 1, wherein the pump feeds the coolant cooled by the radiator from the radiator to the aftercooler.   9. The engine aftercooling system of claim 8, further comprising an ambient air temperature sensor that senses ambient air temperature around the system.   The engine aftercooling system of claim 1, further comprising a fan for sending air so that the air will pass through the radiator.   The engine aftercooling system of claim 13, wherein the controller is capable of controlling a fan speed.   The controller controls the difference between the outside air temperature detected by the outside air temperature sensor and the "temperature of the compressed air obtained from the compressor and supplied to the aftercooler that is cooled or condensed" detected by the inlet temperature sensor. The engine aftercooling system of claim 12, wherein:   16. The engine of claim 15, wherein the controller determines the difference between the ambient air temperature detected by the ambient air temperature sensor and the "temperature of the compressed air discharged from the aftercooler" detected by the outlet air temperature sensor. After cooling system. In order to determine the coolant flow rate at which the coolant temperature and the temperature of the compressed air discharged from the aftercooler are maintained at the optimum temperature, the controller
The difference between the ambient air temperature and the temperature of the compressed inlet air before being cooled by the aftercooler,
The engine aftercooling system according to claim 16, wherein the difference between the ambient air temperature and the temperature of the compressed inlet air discharged from the aftercooler and the temperature of the coolant detected by the coolant temperature sensor are used.   15. The engine aftercooling system of claim 14, wherein the controller controls the fan such that due to the speed of the fan, the compressed inlet air exhausted from the aftercooler is maintained at an optimum temperature.   The controller controls the flow rate of the coolant flowing through the system by a pump so that the compressed inlet air discharged from the aftercooler is maintained at an optimum temperature due to the flow rate of the coolant. The described engine aftercooling system.

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