JP2004218539A - Cooling device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for an engine capable of improving engine performance and effectively performing warm up while making a heat exchanger for the engine compact. <P>SOLUTION: In the cooling device 5 that supplies sea water to the heat exchanger 3 for the engine and cools the engine 1 and an intercooler 2 by fresh water cooled through heat exchange with the supplied sea water, an engine side outlet port 31 for supplying the fresh water to the engine 1 is provided in the midstream position of the heat exchanger 3 for the engine where the heat exchange with the sea water is finished in midstream, and an intercooler side outlet port 32 for supplying the fresh water to the intercooler 2 is provided in the undermost downstream position of the heat exchanger 3 for the engine where the heat exchange with the sea water is completed. In a branch portion between a fresh water discharge pipe 54 for discharging the fresh water from the engine 1 and a by-pass pipe 7 for bypassing the heat exchanger 3 for the engine, a thermostat 71 for guiding the fresh water to the by-pass pipe side and circulating it until the fresh water temperature inside the fresh water discharge pipe 54 reaches 85°C is provided. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling device for an engine, and more particularly to a device for cooling an engine and an intercooler.
[0002]
[Prior art]
Conventionally, as a cooling device for an engine, there is a device provided with an intercooler for cooling the supply air for combustion of the engine, and in this device, an intercooler is provided at a frontmost position in a traveling direction where a traveling wind is most blown, and the intercooler is provided. The passing traveling wind is also blown to a radiator to exchange heat, and the engine is cooled by circulating water cooled by heat exchange with the traveling wind in the radiator (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-115222
[Problems to be solved by the invention]
By the way, in an engine, cooling water is supplied to an engine heat exchanger, and heat exchange is performed between the cooling water supplied to the engine heat exchanger and circulating water flowing through a water jacket of the engine. ing.
[0005]
In recent years, in order to increase output performance, some engines are equipped with an exhaust turbocharger and an intercooler in recent years, and supply circulating water cooled by heat exchange with cooling water to the intercooler and the engine in the engine heat exchanger. By doing so, the supply air supplied to the engine from the intercooler is cooled by the circulating water to increase the air supply efficiency, and the circulating water is also supplied to the engine (water jacket) to effectively cool the engine. Some have been made.
[0006]
However, as described above, the supply of circulating water cooled by heat exchange with cooling water in an engine heat exchanger to an intercooler and an engine has the following problems.
[0007]
That is, in order to supply sufficiently cooled circulating water to the intercooler, the engine heat exchanger needs to have a large capacity with high heat exchange efficiency, which causes a space problem. On the other hand, if the capacity of the engine heat exchanger is small, it is not possible to supply sufficiently cooled circulating water to the intercooler, and the engine performance will deteriorate.
[0008]
Further, in the heat exchanger for the engine, since the heat exchange between the cooling water and the circulating water is always performed, for example, when the engine has a low heat load at the time of warm-up immediately after the start, the cold circulating water is supplied to the engine. Will be supplied. For this reason, in a low-temperature situation where the engine with a low heat load is supercooled by circulating water, the ignition performance deteriorates and the warm-up of the engine is not promoted at all, and excessive time is required to warm up the engine. become.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the engine performance while reducing the size of a heat exchanger for an engine, and to efficiently cool an engine. It is to provide a device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a solution taken by the invention according to claim 1 is to supply cooling water to an engine heat exchanger, and by using circulating water cooled by heat exchange with the supplied cooling water, It is assumed that an engine cooling device is designed to cool the engine and the intercooler. The engine heat exchanger is provided with an engine-side outlet that circulates water to the engine and an intercooler-side outlet that circulates water to the intercooler, and cools the engine-side outlet. The intercooler side outlet is located at the most downstream position of the engine heat exchanger that completes heat exchange with the cooling water, while being provided at an intermediate position of the engine heat exchanger that finishes heat exchange with water halfway. Provided.
[0011]
By this specific matter, the engine is supplied with circulating water that is not sufficiently cooled from the engine-side outlet at a position on the engine heat exchanger halfway through which heat exchange with the cooling water has been completed halfway. Prevents the engine with a low heat load from being overcooled by circulating water during warm-up immediately after starting, etc., and enhances ignition performance, promotes engine warm-up efficiency and reduces the time required for engine warm-up It is possible to do.
[0012]
Then, sufficiently cooled circulating water is supplied to the intercooler from the intercooler-side outlet at the most downstream position of the engine heat exchanger that has completed heat exchange with the cooling water. For this reason, it is not necessary to use a large-capacity heat exchanger with high heat exchange efficiency for supplying (discharging) sufficiently cooled circulating water to the intercooler, so that the intercooler can be compact, and the engine cooler can be used. Space saving of the heat exchanger can be achieved. In addition, since the sufficiently cooled circulating water is supplied to the intercooler, the supply air whose temperature has been raised by the pressurizing action of the supercharger is effectively cooled, and the charging efficiency of the supply air is increased to improve the engine performance. Can be improved.
[0013]
Further, in the invention according to claim 2, a restriction means for restricting the amount of circulating water discharged to the engine is provided at the engine side outlet.
[0014]
With this specific matter, the amount of circulating water to be drawn out from the engine-side outlet at an intermediate position is limited by the restricting means due to the flow resistance of the circulating water flowing through the heat exchanger for the engine. Thus, the circulation amount of the circulating water flowing toward the intercooler side outlet at the most downstream position in the internal heat exchanger is secured. In addition, the flow rate and flow rate of the circulating water flowing toward the intercooler-side outlet at the most downstream position decrease due to the circulating water led out from the engine-side outlet at a position halfway through the engine heat exchanger. The heat exchange between the circulating water flowing toward the outlet and the cooling water can be effectively performed, and the circulating water discharged from the intercooler-side outlet can be efficiently cooled.
[0015]
Further, in the invention according to claim 3, the introduction pipe for introducing the circulating water into the engine heat exchanger is provided with a bypass pipe that bypasses the engine heat exchanger and communicates with the outlet pipe downstream of the intercooler side outlet. ing. At the branch between the introduction pipe and the bypass pipe, switching means for switching between a first position for communicating the introduction pipe with the engine heat exchanger and a second position for communicating the introduction pipe with the bypass pipe is provided. The switching means is switched to the second position until the temperature of the circulating water reaches a predetermined temperature.
[0016]
According to this specific matter, the circulating water is switched by the engine heat exchanger until the temperature of the circulating water reaches a predetermined temperature by the switching means provided at the branch portion between the introduction pipe and the bypass pipe for the engine heat exchanger. Since the heat exchange with the cooling water is avoided, the cold circulating water cooled by the engine heat exchanger is reliably prevented from being supplied to the intercooler and the engine. In addition, until the temperature of the circulating water reaches the predetermined temperature, the supply air is heated by the circulating water supplied to the intercooler, so that the engine with a low heat load can be used for warming-up immediately after starting. The intercooler functions as an air-supply heater that heats the supplied air, dramatically improving ignition performance during warm-up, etc., further promoting engine warm-up efficiency, and reducing the time required for engine warm-up. It is possible to further reduce the length.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
FIG. 1 is a configuration diagram showing an embodiment in which a cooling device according to the present invention is applied to a marine engine. The engine 1 is provided with an exhaust turbocharger (not shown). A downstream end of a boost pipe (not shown) extending from a compressor outlet of the exhaust turbocharger and an upstream end of an intake pipe (not shown) whose downstream end is connected to an intake manifold (not shown). , An intercooler 2 is provided. In this case, the supply air pressurized by the compressor of the exhaust turbocharger is sent to the combustion chamber of the engine 1 via the intake manifold after heat exchange in the intercooler 2.
[0019]
The engine 1 and the exhaust manifold (not shown) are provided with a water jacket (not shown). An engine heat exchanger 3 that supplies fresh water as circulating water is connected to the water jacket and the intercooler 2.
[0020]
The downstream end of a seawater pumping pipe 42 in which a seawater pump 41 for pumping seawater as cooling water is connected to one end (the lower end in the figure) of the heat exchanger 3 for the engine. The upstream end of a seawater discharge pipe 43 for discharging seawater taken in from the pipe 42 is connected to the other end (the upper end in the figure). Reference numeral 44 denotes an engine oil cooler provided in the middle of the seawater discharge pipe 43.
[0021]
The engine heat exchanger 3 is connected to the upstream end of an engine-side fresh water supply pipe 51 that supplies fresh water to the water jacket (engine 1), and serves as an outlet pipe that supplies fresh water to the intercooler 2. The upstream end of the intercooler-side fresh water supply pipe 52 is connected. A fresh water pump 53 for supplying fresh water is provided in the middle of the engine-side fresh water supply pipe 51. The upstream end of a fresh water discharge pipe 54 serving as an introduction pipe for discharging fresh water supplied into the engine 1 and the exhaust manifold via the engine-side fresh water supply pipe 51 is connected to the water jacket. The downstream end of the fresh water discharge pipe 54 is connected to one end of the heat exchanger 3 for the engine, that is, to the fresh water inlet 30 at the upstream end, so that the fresh water is introduced into the heat exchanger 3 for the engine. The upstream end of an intercooler-side fresh water discharge pipe 55 that discharges fresh water supplied to the inside through the intercooler-side fresh water supply pipe 52 is connected to the intercooler 2. The downstream end of the intercooler-side fresh water discharge pipe 55 is connected to the middle of the engine-side fresh water supply pipe 51 located upstream of the fresh water pump 53. The engine 1 and the exhaust manifold (water jacket), the intercooler 2 and the engine heat exchanger 3 are connected to the engine side fresh water supply pipe 51, the intercooler side fresh water supply pipe 52, the fresh water discharge pipe 54 and the intercooler side. The intercooler 2, the engine heat exchanger 3, the engine-side freshwater supply pipe 51, the intercooler-side freshwater supply pipe 52, the freshwater discharge pipe 54, and the intercooler-side freshwater discharge pipe are connected by a freshwater discharge pipe 55 so that freshwater circulation is possible. The cooling device 5 is constituted by 55.
[0022]
The engine heat exchanger 3 exchanges heat between seawater taken in by the seawater pumping pipe 42 and fresh water circulated through the circulation path 5. The upstream end of the engine-side freshwater supply pipe 51 is connected to the engine heat exchanger 3. The engine-side supply port 31 serving as an engine-side outlet for discharging fresh water to the exhaust manifold 1 (water jacket) and the upstream end of an intercooler-side fresh water supply pipe 52 are connected to discharge the fresh water to the intercooler 2. An intercooler-side supply port 32 is provided as an intercooler-side outlet.
[0023]
The engine-side supply port 31 of the engine heat exchanger 3 is provided at an intermediate position of the engine heat exchanger 3 where heat exchange with seawater is terminated halfway, while the intercooler-side supply port 32 is provided with seawater. It is provided at the most downstream position of the engine heat exchanger 3 for completing the heat exchange with the engine. A throttle 6 is provided on the upstream side of the engine-side fresh water supply pipe 51 located immediately downstream of the engine-side supply port 31, as a restricting means for limiting the supply amount of fresh water to the engine 1. In this case, the supply amount of fresh water to be supplied to the engine 1 from the engine-side supply port at an intermediate position is restricted by the throttle 6 due to the flow resistance of the fresh water flowing in the engine heat exchanger 3, and the fresh water is further downstream. It is made to flow toward the side intercooler side supply port 32.
[0024]
In the middle of the fresh water discharge pipe 54 for introducing fresh water into the engine heat exchanger 3, the fresh water discharge pipe 54 bypasses the engine heat exchanger 3 and communicates with the intercooler-side fresh water supply pipe 52 downstream of the intercooler-side supply port 32. The upstream end of the bypass pipe 7 is connected. A thermostat 71 as switching means is provided at a branch between the fresh water discharge pipe 54 and the bypass pipe 7. The thermostat 71 has a function of switching between a first position in which the fresh water discharge pipe 54 communicates with the engine heat exchanger 3 and a second position in which the fresh water discharge pipe 54 communicates with the bypass pipe 7. Until the temperature of the fresh water from the engine 1 and the exhaust manifold discharged into the pipe 54 reaches a predetermined temperature (for example, 85 ° C.), it is switched to the second position and is not introduced into the engine heat exchanger 3. It is introduced into the bypass pipe 7 and circulated.
[0025]
In this case, the thermostat 71 switches to the first position when the temperature of the fresh water discharged from the engine 1 and the exhaust manifold into the fresh water discharge pipe 54 exceeds a predetermined temperature (for example, 85 ° C.), and the fresh water is cooled by the engine heat. It will be introduced into the exchanger 3. At this time, while the heat exchange with the seawater in the engine heat exchanger 3 is completed halfway, the outlet temperature of the fresh water supplied from the engine side supply port 31 becomes about 75 ° C., while the seawater and the seawater are further downstream. And the outlet temperature of the fresh water supplied from the intercooler side supply port 32 becomes about 60 ° C.
[0026]
Therefore, in the above embodiment, the temperature of the fresh water discharged from the engine 1 and the exhaust manifold (water jacket) by the thermostat 71 provided at the branch between the fresh water discharge pipe 54 and the bypass pipe 7 is equal to the predetermined temperature (for example, Until the temperature reaches 85 ° C., heat exchange with seawater in the engine heat exchanger 3 is avoided, so that when the engine 1 is warmed up immediately after starting, the engine 1 discharged into the fresh water discharge pipe 54 and the engine 1 Since the temperature of the fresh water from the exhaust manifold is lower than a predetermined temperature (for example, 85 ° C.), the thermostat 71 is switched to the second position, and the fresh water is passed through the bypass pipe 7 without being introduced into the engine heat exchanger 3. The fresh water circulated and cooled by the engine heat exchanger 3 is supplied to the intercooler 2 and the engine 1 side. Is reliably prevented. In addition, the thermostat 71 switches to the first position when the temperature of the fresh water from the engine 1 and the exhaust manifold discharged into the fresh water discharge pipe 54 exceeds a predetermined temperature (for example, 85 ° C.), and the fresh water exchanges heat for the engine. The engine 1 and the exhaust manifold (water jacket) are supplied from the engine-side supply port 31 at an intermediate position of the heat exchanger 3 for the engine, which has completed heat exchange with seawater. Uncooled water is supplied to the engine 1 and the engine 1 with a low heat load is supercooled by the fresh water even if the engine is continuously operated for a long time in a light load / low rotation range near idling. Is prevented. As a result, the ignition performance of the engine 1 having a low heat load at the time of warm-up immediately after starting or the like is enhanced, and the warm-up of the engine 1 can be promoted to reduce the time required for warm-up of the engine 1.
[0027]
In addition, when the temperature of fresh water from the engine 1 and the exhaust manifold discharged into the fresh water discharge pipe 54 is lower than a predetermined temperature (for example, 85 ° C.), the thermostat 71 is switched to the second position to bypass the fresh water. Since the water is supplied to the intercooler 2 through the pipe 7 and the intercooler-side freshwater supply pipe 52, the supply of air is increased by the freshwater supplied to the intercooler 2 until the temperature of the circulating water reaches a predetermined temperature. The intercooler 2 functions as an air supply heater for heating the air supplied to the engine 1 having a low heat load at the time of warming up immediately after the start, and the ignition performance at the time of warming up is improved. The warm-up efficiency of the engine 1 is further enhanced by drastically increasing, and the time required for warming up the engine 1 can be further reduced.
[0028]
In the intercooler 2, sufficiently cooled fresh water from the intercooler-side supply port 32 at the most downstream position of the engine heat exchanger 3 that has completed heat exchange with seawater is supplied via the intercooler-side freshwater supply pipe 52. By supplying the water to the intercooler 2, it is not necessary to use a large-capacity heat exchanger for the engine with high heat exchange efficiency in supplying the sufficiently cooled fresh water to the intercooler 2. Space of the heat exchanger 3 can be reduced.
[0029]
In addition, since the sufficiently cooled fresh water is supplied to the intercooler 2, the supply air whose temperature has been increased by the pressurizing action of the exhaust turbocharger (supercharger) is effectively cooled, and the charging efficiency of the supply air is reduced. It can be raised to improve engine performance.
[0030]
Further, the supply amount of fresh water to be supplied to the engine 1 from the engine-side supply port at an intermediate position is restricted by the throttle 6 due to the flow resistance of the fresh water flowing in the engine heat exchanger 3 and the like. Of the fresh water flowing toward the intercooler side supply port 32 can be secured. Moreover, the flow rate and flow rate of fresh water flowing toward the intercooler-side supply port 32 at the most downstream position are reduced by the fresh water supplied from the engine-side supply port 31 at a position halfway through the engine heat exchanger 3 to the engine 1 side. The heat exchange between the fresh water flowing toward the intercooler side supply port 32 and the seawater can be effectively performed, and the fresh water supplied to the intercooler 2 from the intercooler side supply port 32 can be efficiently cooled.
[0031]
Note that the present invention is not limited to the above embodiment, and includes various other modifications. For example, in the above-described embodiment, the case where the cooling device 5 is applied to the marine engine 1 has been described. However, it goes without saying that the cooling device may be applied to an engine mounted on land.
[0032]
【The invention's effect】
As described above, according to the engine cooling device of the first aspect of the present invention, the engine-side outlet is provided at an intermediate position of the engine heat exchanger that completes the heat exchange with the cooling water. By providing an intercooler-side outlet at the most downstream position of the engine heat exchanger that completes heat exchange with water, circulating water that is not sufficiently cooled by the engine heat exchanger can be warmed up immediately after startup, etc. The engine can be supplied to an engine having a low heat load, prevent the engine from being excessively cooled by circulating water, enhance ignition performance, promote the engine warm-up efficiency, and reduce the time required for engine warm-up. On the other hand, heat exchange with cooling water is completed without using a large-capacity engine heat exchanger with high heat exchange efficiency, and sufficiently cooled circulating water is supplied to the intercooler to reduce the size of the engine heat exchanger. To reduce the space required for the heat exchanger for the engine, and to effectively cool the supply air whose temperature rises due to the pressurizing action of the supercharger to increase the charge efficiency of the supply air. Performance can be improved.
[0033]
Further, according to the engine cooling device of the second aspect of the present invention, by providing the engine-side outlet with the limiting means for limiting the amount of circulating water led out to the engine, the inside of the engine heat exchanger is located at the most downstream position. The amount of circulating water flowing toward the intercooler side outlet can be secured. In addition, the flow rate and flow rate of the circulating water flowing toward the intercooler-side outlet at the most downstream position are reduced to effectively conduct heat exchange with the cooling water, and the circulating water discharged from the intercooler-side outlet is efficiently used. Can be well cooled.
[0034]
Furthermore, according to the engine cooling device of the third aspect of the present invention, heat exchange between the circulating water and the cooling water in the engine heat exchanger is avoided until the temperature of the circulating water reaches a predetermined temperature. Thus, the supply of the cold circulating water cooled by the engine heat exchanger to the intercooler and the engine can be reliably prevented. In addition, until the temperature of the circulating water reaches a predetermined temperature, the circulating water supplied to the intercooler heats the air supplied to the engine having a low heat load at the time of warming-up immediately after starting or the like. As a result, the intercooler functions to dramatically improve the ignition performance during warm-up and the like, thereby further promoting the warm-up efficiency of the engine and further shortening the time required for warming up the engine.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing paths of seawater and fresh water of an engine cooling device according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 Intercooler 3 Engine heat exchanger 31 Engine side supply port (engine side outlet)
32 Intercooler side supply port (Intercooler side outlet)
5 Cooling device 52 Intercooler side fresh water supply pipe (outlet pipe)
54 Shimizu discharge pipe (introduction pipe)
6 Aperture (Limiting means)
7 bypass pipe 71 thermostat (switching means)

Claims (3)

An engine cooling device that supplies cooling water to an engine heat exchanger, and cools an engine and an intercooler by circulating water cooled by heat exchange with the supplied cooling water,
The engine heat exchanger includes an engine-side outlet that circulates water to the engine, and an intercooler-side outlet that circulates water to the intercooler,
The engine-side outlet is provided at an intermediate position of an engine heat exchanger that finishes heat exchange with cooling water halfway,
The engine cooling device, wherein the intercooler-side outlet is provided at a most downstream position of an engine heat exchanger that completes heat exchange with cooling water. The engine cooling device according to claim 1,
A cooling device for an engine, wherein a restriction means for restricting a supply amount of circulating water to the engine is provided at the engine-side outlet. The engine cooling device according to claim 1,
The introduction pipe for introducing the circulating water into the engine heat exchanger is provided with a bypass pipe that bypasses the engine heat exchanger and communicates with the outlet pipe downstream of the intercooler side outlet.
At a branch portion between the introduction pipe and the bypass pipe, switching means for switching between a first position for communicating the introduction pipe with the heat exchanger for the engine and a second position for communicating the introduction pipe with the bypass pipe is provided. The switching means is switched to the second position until the temperature of the circulating water reaches a predetermined temperature.

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