JPS60212617A - Water-cooled turbocharger cooling device - Google Patents

Abstract

PURPOSE:To prevent a large loss of energy due to overcooling of a turbine casing by forming a circulating circuit through which a cooling water flows, between an exhaust manifold, a turbocharger, and a fresh-water cooler. CONSTITUTION:When an engine is started in a cold state, as a thermostat 53 keeps a flow path on a piping 55 side closed while a bypass 54 is opened, the cooling water from an outlet passage 52 is refluxed through the bypass 54 into a cooling water tank 50. And the cooling water circulates between the pump 50 and each water jacket of an engine body 21, preventing cylinders, etc. from being overcooled. When the temp. of the cooling water reaches a set temp. the thermostat 53 opens the flow path on the piping 55 side. Thereby, the cooling water leaving the pump 50 enters a fresh water cooler 31 through the engine body 21. The cooling water exchanges heat with sea water flowing through a cooling pipe 30 in the cooler 31, and, after flowing through the water jacket 26 of an exhaust manifold 22 to cool an exhaust pipe 24, it is refluxed into the pump 50.

Description

[Detailed description of the invention] [Industrial application field]

=1- The present invention relates to a cooling device for a water-cooled turbocharger installed in an air supply system of an internal combustion engine. (Prior Art) Among the superchargers attached to the air supply system for the purpose of supplying air to an internal combustion engine such as a diesel engine, the turbocharger drives a gas turbine using the compressive force of exhaust gas, and In an exhaust gas turbine supercharger, a so-called turbocharger, which performs forced supercharging by a compressor coaxially integrated with a turbine, a turbine casing that rotatably accommodates the gas turbine is directly exposed to high-temperature and high-pressure VR gas, Since large thermal stress occurs here, in order to prevent this, the outer surface of the turbine casing is surrounded by a water jacket, and cooling water is constantly supplied to the water jacket. Figure 1 shows a cooling circuit for a marine internal combustion engine equipped with a conventional water-cooled turbocharger.
1: Engine body, 1211'j Water-cooled exhaust manifold with built-in water jacket, 131c 2- Built-in cooling pipe (4) placed on the top of the exhaust manifold (2) and allowing seawater to flow inside. Shimizu Cooler, [5
1 is connected to the exhaust manifold (21), a turbocharger with a water jacket (6) that covers the turbine engine inside, (7) is a cooling water pump, (81r
All the thermostats that switch the flow of cooling water according to the temperature of the rl cooling water are shown. , the cooling water discharged from the cooling water pump (71) enters the cylinder block [11 through the cooling water inlet passage (9), and passes through the cooling water outlet passage (10) to the thermostat (8) and the bypass. It returns to the cooling water pump (7) through the passage (111) and circulates between them repeatedly, and when the temperature of the cooling water rises by -L and exceeds the valve opening setting temperature of the thermostat (8), the above-mentioned The bypass passage (11) is closed,
Instead, the cooling water coming out of the thermostat (8) is split into two directions from branch point 02I, as shown by the dashed-dotted line arrow.
One side passes through the passage (+31i and connects to the fresh water cooler)

It enters [3], where it exchanges heat with the seawater passing through the cooling pipe [4].
After lowering the temperature, i'+Ir passes through the water jacket in the exhaust manifold (2) and returns to the cooling water pump (7) from the passage (14). At the same time, the cooling water flowing in the (lj4 direction) enters the water jacket (6) from the cooling water inlet (16) provided at the bottom of the turbocharger [5+] through the piping (1ω), where it flows into the turbine casing. After cooling, the fresh water cooler 13 is passed from the cooling water outlet 07) to the piping 08).
1, merges with the cooling water that has exchanged heat with the seawater, and ni
A cooling circuit is installed to provide reflux to the cold JJ water pump (7). However, in the turbocharged internal combustion engine equipped with the conventional cold 1JJ equipment fE1 as described above, after the thermostat (8) is opened, the water jacket (6) of the nir turbocharger 151 is constantly
Since the cooling water is forcibly sent through the pipe (15),
The turbine casing becomes supercooled and a large amount of energy is taken away from the exhaust gas.The efficiency of the turbocharger itself decreases, and all of the cooling water cannot be sent to the fresh water cooler (31), so

[31's heat exchange efficiency decreases, requiring a larger heat exchanger, and also requires a long pipe 051 to connect to the thermostat [81 torboch 4-yager (5)] and a support to support it. Therefore, there was a problem that the cost of the device increased and the maintenance became complicated.
Focusing on issues such as reduced efficiency of fresh water coolers and increased piping length, the lower part of the exhaust manifold's water jacket and the lower part of the turbocharger's water jacket were connected with short piping to communicate with each other, and the exhaust manifold and the lower part of the water jacket were connected. A circulation circuit in which cooling water freely flows is formed between the turbocharger and the fresh water cooler, and the turbocharger is cooled while the cooling water is naturally circulated through the circulation circuit according to the thermosiphon principle, thereby eliminating the problem fish all at once. This is something that we are trying to resolve. [Configuration of the Invention] The configuration of the present invention for achieving the above object includes
A fresh water cooler equipped with a cooling water storage space communicating with the water jacket of the exhaust manifold is placed and fixed on the upper surface of the exhaust manifold, and the outer surface of the turbine casing is connected to the water jacket of the exhaust manifold. Connect the exhaust inlet of the turbocharger covered with
A cooling device for a water-cooled turbocharger that communicates between the upper part of the water jacket of the turbocharger and the upper part of the cooling water storage space in the fresh water cooler is connected to the lower part of the water jacket of the exhaust manifold and the lower part of the water jacket of the turbocharger. and communicate with each other to form a path υ1 through which cooling water can flow through the exhaust manifold, turbocharger, and fresh water cooler. [Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. Fig. 2 is a schematic diagram of a cooling circuit of a marine internal combustion engine to which the water-cooled turbocharger cooling device of the present invention is applied, and Fig. 3 is a side sectional view of the main parts of an internal combustion engine to which the present invention is applied. - In each of these figures, 1) the engine body, and 2 the engine body 1) the exhaust D(231, (23+...)
・Connect to 2! A water-cooled exhaust manifold, in which an external wall (251) surrounds an exhaust pipe with a predetermined gap, and a water jacket (261) is formed around the outer circumference of the exhaust pipe.
A bundle of a large number of cold A-tubes (color 0) through which secondary cooling water such as seawater flows is housed in a cooling water storage space 29+ in a casing sill that is integrally cast with the external wall of the exhaust manifold. a fresh water cooler, the cooling water storage space (e29) inside the fresh water cooler being in communication with the water jack of the exhaust manifold (3);
The fresh water cooling water introduced from the fresh water 01) provided at the upper part of the fresh water cooler η flows into the inside of the cylindrical body 4 from the 9J notch [32a] of the cylindrical body provided on the outer periphery of the cooling pipe e (El). Baffle plates G31 and (331... The water enters the internal water jacket 0 and flows out from the fresh water outlet (3 lamps) provided on the external wall of the exhaust manifold (20). ?In Kannai, seawater cooling power 1 water pumped up by a seawater pump (not shown) is supplied to a sea water cooler 11 e (lit) installed on the external wall (c) of the fresh water cooler transmission, and a large number of cooling pipes are installed. On the east side of (11), the water flows through the cold 711 pipe (11) in the lower half into the lid au' CQ attached to the fresh water cooler η, where it changes direction and flows into the cold water in the upper half. JJI pipe (2) o-1 street, seawater outlet C (
η The force of ejecting it outside the machine causes it to become counterfeit. In the figure, the water supply mark provided on the surface of the casing (c) of the 0 barrel tri Fm fresh water tank (b) is a filler cap that is closed and attached. 10,000, (for the exhaust of the exhaust manifold recorder [1[24al], turbine casing 111
11 exhaust intake "I [40al], and the turbocharger 4' (!11
The first side of the turbine casing has a predetermined gap.
The turbocharger is surrounded by an outer casing (41) integrally formed by casting with the turbocharger casing (00), and a water jacket (1 jacket) is formed between both casing frames. 〇Spring water jacket HJ-, f
, = 8 - the joint vibe (4) attached to the lower part of the external casing ell, the exhaust manifold (the joint vibe 04 attached to the leveled part of the two external walls), and the circumferential joint pipe (4)
4) The water jaterra on the exhaust manifold side is communicated with the lower part of the exhaust manifold by the piping installed between
1) between the cooling water joint pipe f461 provided in the fresh water cooler cutting force and the joint pipe 0η provided on the outer surface of the casing (c) of the fresh water cooler cutting force It communicates with the cooling water storage space η, and each of the pipes I
A @, (4F! The cooling water passage in I is connected to the fresh water cooler η
It constitutes a circulation passage that can freely flow between the cooling water storage space of the engine, the exhaust manifold (27J water jacket 12F5), and the turbocharger water jacket (4). The cooling water discharged from the fresh water outlet of e2Z is returned to the cooling water pump through piping as shown in Figure 2, where it is pressurized and flows into the cooling water inlet passage.

[
51) enters the water inside the engine body,
After the high temperature parts such as the cylinder block and cylinder head are completely cooled, the cooling water flows into the thermostat [53] through the cooling water outlet passage 9- [52] i.
n: Bypass passage while the degree is low

If the temperature of the flow through [54] rises to the cold water pump side, the piping

[55] A cold ff+water circuit is constructed so that the fresh water flows into the fresh water inlet (31) of the fresh water supply through [55]. The water-cooled turbocharger cooling power device of the present invention is described.
It has a configuration as shown in 2. Next, its operation will be explained in detail. First, cold start of the engine 11:? When the temperature of the engine cooling water is below the valve opening temperature of the thermostat (53), the thermostat (53) is the piping.

[55]
Since the side flow passage is closed and the bypass passage (54) is fully opened, the cooling water outlet passage (152) is completely opened.
The entire amount of cold J11 water flowing into +531 flows into the bypass passage as shown by the solid line arrow in Figure 2.

The cooling water is returned to the cooling water pump group through [54], and the cooling water pump R10) and the engine body 1)
The water is repeatedly circulated between the inner water jacket and the cylinder to prevent overcooling of the cylinder, etc.Next, the salinity of the cold water is adjusted to the thermostat h [53] o
When the nR valve set temperature is reached, the thermostat (53
]=10- is the piping

[55] In order to open the side flow path, the cooling water pump (55)
The cooling water discharged from the cooling water enters the engine body (21) as shown by the dashed-dotted line arrow in Figure 2, cools the high temperature parts of the cylinder block and cylinder head, and then enters the cooling water outlet passage [52].
,thermostat

[53] and piping

It enters the fresh water cooler (3I) through [55], where it exchanges heat with the seawater passing through the cooling pipe (3o) and releases heat, and passes through the exhaust manifold (221 water jacket) (26) to the exhaust pipe. (
241, and is returned to the cooling water pump (50) from the fresh water outlet (round) through the piping (49). Note that while the cooling water is being forcedly circulated by the cooling water pump (50), the turbocharger (39 ) to the cooling water in the water tank (4 tons), the turbine casing (4 tons)
0) to prevent it from overheating, and the cooling water, which has increased in temperature by removing heat and has a lower specific gravity, flows out to the fresh water cooler (2η side) through the upper pipe (48).
Also, from the exhaust 73 hold cut 2, the water jacket is used to supplement this) (26) The relatively low temperature cooling water at the bottom flows through the pipe (4-way) to the turbocharger (39) side and enters the water jacket (42). In this way, the cold J water in the water jacket of the turbocharger (39) is circulated at a speed corresponding to the temperature rise of the turbine casing (decoy) by the principle of thermosiphon, and is circulated through the exhaust manifold (
Since the water is sequentially replaced with the cold water in (b), unlike the case where the turbine casing (39) is forcibly cooled with cooling water, overcooling is suppressed and at the same time the efficiency of the turbocharger (39) is reduced. will also be prevented. In the above embodiment, the lower part of the water jacket (2 (support)) of the exhaust manifold and the turbocharger (39
) (The case where the lower part of 14 is connected with a short piping to shorten the piping is shown, but the invention is not limited to this. For example, the exhaust manifold (221 Turbocharger (39) (!-17
) Attach both water jackets (2 (support), (4') to the mating surfaces.
4'f: It is also possible to construct a circulation circuit by drilling communication holes for communication with each other, and it goes without saying that the design can be modified as appropriate without departing from the spirit of the invention. [Effects of the Invention] As described above, the water-cooled turbocharger cooling device of the invention includes a fresh water cooler with an internal water passage connected to the upper surface of the exhaust manifold, and a water-cooled turbocharger connected to the exhaust manifold. In a cooling device for a water-cooled turbocharger in which the upper part of the water jacket and the cooling water storage space in the fresh water cooler are communicated with each other, the lower part of the water jacket of the exhaust manifold and the lower part of the water jacket of the turbocharger are communicated with each other, By forming a circuit in which cooling water can freely flow between the manifold, turbocharger, and fresh water cooler, the cooling water is naturally circulated within the circuit using the principle of thermosiphon, and the turbocharger is heated. Since it is designed to cool the turbine casing,
The cooling water in the turbocharger's water jacket is replaced at a rate that corresponds to the rise in temperature of the turbine casing, which prevents the turbine casing from overflowing, unlike when cooling water was forcibly supplied by a cooling water pump. It is cooled and there is no concern about large energy loss, and it maintains the efficiency of the turbocharger and exhibits the excellent effect of coupling on the output direction of the engine. Moreover, according to the present invention, it is possible to communicate the water jacket of the adjacent exhaust manifold with the water jacket of the L turbocharger using a short pipe, so that the cooling water pipe can be shortened to a large length. This is expected to have the practical effect of suppressing the soaring cost of internal combustion engine equipment and simplifying engine maintenance.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a cooling circuit of a conventional internal combustion engine with a turbocharger, FIG. 2 is a schematic diagram showing an example of a cooling circuit of an internal combustion engine with a turbocharger to which the cooling device of the present invention is applied, and FIG. FIG. 2 is a sectional side view of a main part of an internal combustion engine to which fully FrA is applied. (221...Exhaust manifold. [24al...Exhaust outlet. (A)...Water jacket

[Exhaust manifold side] (27)...Shimizu Cooler. Q9)...Cooling water storage space. (39)...turbocharger. No)...Turbine casing.

[4oa)...Exhaust inlet. 04...Water jacket [turbocharger side]. 15- Figure 1 Ne Figure 12

Claims (1)

[Claims] i. A fresh water cooler equipped with a cooling water storage space that communicates with the water jacket of the exhaust manifold is placed and fixed on the upper surface of the exhaust manifold; In a cooling device for a water-cooled turbocharger, in which the exhaust inlet of the turbocharger covered with water is connected, and the upper part of the water jet of the turbocharger is communicated with the upper part of the cooling water storage space in the fresh water Tara, the water in the exhaust manifold is connected to the A water-cooled turbocharger characterized in that a lower part of the janut and a lower part of the water janut of the turbocharger are communicated with each other to form a circuit between the exhaust manifold, the turbocharger, and the fresh water cooler in which cooling water can freely flow. Cooling system.