Marine diesel engine charge air cooling system

Abstract

The application discloses a turbocharged air cooling system for a marine diesel engine, which comprises a turbocharged air cooler, a first four-way valve, a second four-way valve, a water pump and a control cylinder; the exhaust outlets of the turbocharged air cooler are communicated with the air inlets of the diesel engine and the control cylinder respectively, and the two compressed air outlets of the control cylinder are communicated with the air inlets of the first four-way valve and the second four-way valve respectively; the upper interface of the first four-way valve is communicated with the inlet of the first cooler, the inner side interface is communicated with the outlet of the second cooler, and the outer side interface is communicated with the cooling water system of the diesel engine; the two upper interfaces of the second four-way valve are communicated with the outlet of the first cooler and the inlet of the second cooler respectively, and the two lower interfaces are communicated with the cooling water outlet pipe and the cooling water inlet pipe respectively; the application can adjust the temperature of the turbocharged air under different loads of the diesel engine, and has simple structure and convenient installation.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of marine diesel engine supercharged air cooling system, especially a kind of system using cooling water to adjust supercharged air temperature, belongs to the technical field of internal combustion engine cooling equipment. BACKGROUND

[0002] The diesel engine currently in use is all turbocharged diesel engine, its principle is to use the energy remaining in exhaust gas, after air compression becomes supercharged air, enters diesel engine combustion, improves the intake density, and further improves the power and economy of diesel engine.Turbocharger carries out compression to air, and the temperature of supercharged air will increase, and generally turbocharged diesel engine will be used with supercharged air cooler, and supercharged air is cooled after entering diesel engine combustion.The existing diesel engine supercharged air cooling system is generally cooled by low-temperature cooling water (25 36℃) through air cooler to cool supercharged air, which can fully cool supercharged air in the high load (80%100%) interval of diesel engine, and provide enough air for diesel engine combustion, but in the low load interval (0 25%) of diesel engine, it is impossible to increase the temperature of supercharged air, and since the thermal load of diesel engine is low at this time, the temperature in the cylinder is low, the gap between cylinder liner and piston ring is increased, the compression pressure is low, and the combustion is poor, and too low supercharged air temperature will further reduce the temperature in the cylinder, which is not conducive to combustion. SUMMARY

[0003] The purpose of the present application is to provide a kind of marine diesel engine supercharged air cooling system with simple structure, convenient to use, can adjust the temperature of supercharged air by cooling water.

[0004] The present application is realized by the following technical scheme:

[0005] A marine diesel engine supercharged air cooling system comprises a supercharged air cooler, a first four-way valve, a second four-way valve, a water pump and a control cylinder; an air inlet of the supercharged air cooler is communicated with an exhaust port of a diesel engine turbocharger through a pipeline, an air outlet of the supercharged air cooler is communicated with an air inlet of the diesel engine and an air inlet of the control cylinder through two pipelines respectively, a lower side of the control cylinder is provided with a compressed air inlet, a first compressed air outlet on an upper side of the control cylinder is communicated with an air inlet of the first four-way valve through a pipeline, and a second compressed air outlet on the upper side of the control cylinder is communicated with an air inlet of the second four-way valve through a pipeline; a lower interface of the first four-way valve is communicated with a cooling water outlet pipe, an upper interface of the first four-way valve is communicated with an inlet of a first cooler in the supercharged air cooler through a pipeline, an inner interface of the first four-way valve is communicated with an outlet of a second cooler in the supercharged air cooler through a pipeline, and an outer interface of the first four-way valve is communicated with an outlet of a diesel engine cooling water system through a pipeline; a first upper interface of the second four-way valve is communicated with the outlet of the first cooler in the supercharged air cooler, a second upper interface of the second four-way valve is communicated with the inlet of the second cooler in the supercharged air cooler, a first lower interface of the second four-way valve is communicated with the cooling water outlet pipe, and a second lower interface of the second four-way valve is communicated with a cooling water inlet pipe; an inlet of the water pump is communicated with the cooling water inlet pipe, and an outlet of the water pump is communicated with an inlet of the diesel engine cooling water system.

[0006] The object of the present application can also be further achieved by the following technical measures.

[0007] The marine diesel engine supercharged air cooling system as described above, wherein the control cylinder comprises a cylinder body, a piston arranged in the cylinder body and a spring, both ends of the piston are respectively provided with piston rings, a compressed air passage is arranged in a middle part of the piston and penetrates the piston in a transverse direction, and both ends of the spring are respectively fixedly connected with one end of the piston and one end of the cylinder body.

[0008] The marine diesel engine supercharged air cooling system as described above, wherein the first four-way valve and the second four-way valve are both single-acting pneumatic butterfly valves.

[0009] The marine diesel engine supercharged air cooling system as described above, wherein a thermostatic valve is further arranged on the pipeline between the outer interface of the first four-way valve and the outlet of the diesel engine cooling water system.

[0010] The marine diesel engine supercharged air cooling system as described above, wherein the thermostatic valve is a wax type mechanical thermostatic valve, and the temperature control range is 80-85℃.

[0011] The present application has the advantages of simple structure, convenient installation, easy maintenance, and can realize the regulation of the temperature of the supercharged air under different loads of the diesel engine, meet the actual use requirements of high supercharged air temperature under low load operation and low supercharged air temperature under high load operation of the diesel engine, and the regulation of the supercharged air temperature is completed by mechanical device, low cost and high reliability. When the diesel engine is under low load operation, the cooling water from the diesel engine is used to heat and warm the supercharged air in the supercharged air cooler, and optimize the combustion; when the diesel engine is under medium load operation, the cooling water from the diesel engine and the low-temperature cooling water are used to cool the supercharged air in the supercharged air cooler, and meet the use requirements of the diesel engine; when the diesel engine is under high load operation, the low-temperature cooling water of the diesel engine is used to cool the supercharged air twice in the supercharged air cooler, improve the intake density, and improve the power and economy of the diesel engine. The present application uses the cooling water to regulate the temperature of the supercharged air, and can effectively ensure that the diesel engine can normally operate under different working conditions.

[0012] The advantages and characteristics of the present application will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given by way of example only, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the structural schematic diagram of the present application when the diesel engine is under low load operation;

[0014] Figure 2 is the structural schematic diagram of the present application when the diesel engine is under medium load operation;

[0015] Figure 3 is the structural schematic diagram of the present application when the diesel engine is under high load operation. DETAILED DESCRIPTION

[0016] The present application will be further described below in combination with the drawings and embodiments.

[0017] As Figure 1 , Figure 2 and Figure 3As shown, the present application comprises a charge air cooler 1, a first four-way valve 2, a second four-way valve 3, a water pump 4 and a control cylinder 5. The air inlet 11 of the charge air cooler 1 is communicated with the air outlet 61 of a diesel engine turbocharger 6 through a pipeline, the air outlet 12 of the charge air cooler 1 is communicated with the air inlet 71 of a diesel engine 7 and the air inlet 51 of the control cylinder 5 through two pipelines respectively. The control cylinder 5 comprises a cylinder body 52, a piston 53 arranged in the cylinder body 52 and a spring 54, both ends of the piston 53 are provided with piston rings 55 to form a seal with the inner wall of the cylinder body 52, the middle part of the piston 53 is provided with a compressed air passage 56 which transversely penetrates the piston, both ends of the spring 54 are fixedly connected with one end of the piston 53 and one end of the cylinder body 52 respectively, the lower side of the control cylinder 5 is provided with a compressed air inlet 57, the first compressed air outlet 581 on the upper side of the control cylinder 5 is communicated with the air inlet 21 of the first four-way valve 2 through a pipeline, and the second compressed air outlet 582 on the upper side of the control cylinder 5 is communicated with the air inlet 31 of the second four-way valve 3 through a pipeline. Since the pressure of the charge air increases with the increase of the load of the diesel engine, the position of the piston 53 in the control cylinder 5 can be changed by the pressure change of the charge air, so as to realize the position conversion of the valve plates of the two four-way valves.

[0018] The first four-way valve 2 and the second four-way valve 3 are both single-acting pneumatic butterfly valves. The lower interface 22 of the first four-way valve 2 is communicated with the cooling water outlet pipe 8, the upper interface 23 of the first four-way valve 2 is communicated with the inlet 131 of the first cooler 13 in the charge air cooler 1 through a pipeline, the inner interface 24 of the first four-way valve 2 is communicated with the outlet 141 of the second cooler 14 in the charge air cooler 1 through a pipeline, the outer interface 25 of the first four-way valve 2 is communicated with the outlet 10 of the diesel engine cooling water system through a pipeline, and a thermostatic valve 9 is further arranged on the pipeline between the outer interface 25 of the first four-way valve 2 and the outlet 10 of the diesel engine cooling water system, the thermostatic valve 9 is a wax type mechanical thermostatic valve, and the temperature control range is 80℃-85℃.

[0019] The first upper interface 32 of the second four-way valve 3 is communicated with the outlet 132 of the first cooler 13 in the charge air cooler 1, the second upper interface 33 thereof is communicated with the inlet 142 of the second cooler 14 in the charge air cooler 1, the first lower interface 34 of the second four-way valve 3 is communicated with the cooling water outlet pipe 8, and the second lower interface 35 thereof is communicated with the cooling water inlet pipe 20; the inlet of the water pump 4 is communicated with the cooling water inlet pipe 20, and the outlet thereof is communicated with the inlet 30 of the diesel engine cooling water system.

[0020] As Figure 1As shown, in its natural state, the outer port 25 of the first four-way valve 2 is connected to its upper port 23, and the inner port 24 of the first four-way valve 2 is connected to its lower port 22. The first upper port 32 and the second upper port 33 of the second four-way valve 3 are connected, and its first lower port 34 and the second lower port 35 are connected. When the diesel engine is running at 0-25% load, i.e., low load, the boost air pressure is low, and the piston 53 in the control cylinder 5 is located at... Figure 1 At the position shown, the compressed air passage 56 is not connected to either the first compressed air outlet 581 or the second compressed air outlet 582 of the control cylinder 5. At this time, neither the first four-way valve 2 nor the second four-way valve 3 can supply air. The cooling water (25℃~36℃) is divided into two paths. One path flows directly from the cooling water inlet pipe 20 through the first lower port 35 and the second lower port 34 of the second four-way valve 3 to the cooling water outlet pipe 8. The other path enters the diesel engine 7 via the water pump 4, cools the various components to 85℃, and then enters the first four-way valve via the thermostatic valve 9. The compressed air enters the first cooler 13 of the turbocharged air cooler 1 through the outer port 25 of valve 2 and then through the upper port 23 of the first four-way valve 2, where it is heated. Afterward, it enters the second cooler 14 through the first upper port 32 and the second upper port 33 of the second four-way valve 3, where it is heated again. Then, it enters the first four-way valve 2 through the outlet 141 of the second cooler 14 and the inner port 24 of the first four-way valve 2, and finally exits through the lower port 22 of the first four-way valve 2 into the cooling water outlet pipe 8. In this mode, the temperature of the diesel engine's compressed air before entering the turbocharged air cooler 1 is approximately 50℃~100℃. After being heated by the first cooler 13 and the second cooler 14, the temperature of the compressed air can reach 65℃~75℃, improving the combustion performance of the diesel engine under low load and reducing fuel consumption by 10~15g / kWh.

[0021] like Figure 2As shown, when the diesel engine is operated at 25% to 75% load, i.e. medium load, the pressure of the supercharged air is increased, the supercharged air pushes the piston 53 in the control cylinder 5 to move to the right to the position shown in the figure, at this time the compressed air passage 56 is communicated with the second compressed air outlet 582 of the control cylinder 5, the first four-way valve 2 is not supplied with air, the outer interface 25 of the first four-way valve 2 is communicated with the upper interface 23 thereof, the inner interface 24 of the first four-way valve 2 is communicated with the lower interface 22 thereof, the second four-way valve 3 is supplied with air, the first upper interface 32 of the second four-way valve 3 is communicated with the first lower interface 34 thereof, and the second upper interface 33 is communicated with the second lower interface 35 thereof. The cooling water is divided into two paths, one path enters the second cooler 14 through the second lower interface 35 and the second upper interface 33 of the second four-way valve 3, and after the supercharged air is cooled, enters the cooling water outlet pipe 8 through the inner interface 24 and the lower interface 22 of the first four-way valve 2, and the other path enters the diesel engine 7 to cool various components and reaches 85°C, enters the first four-way valve 2 through the thermostatic valve 9, and then enters the first cooler 13. Since the temperature of the supercharged air has reached above 100°C when the diesel engine is above 25% load, the supercharged air can be cooled, and then enters the cooling water outlet pipe 8 through the first upper interface 32 and the first lower interface 34 of the second four-way valve 3. In this mode, the temperature of the supercharged air before entering the supercharged air cooler 1 is about 100°C to 200°C, and after being cooled by the first cooler 13 and the second cooler 14, the temperature of the supercharged air can be reduced to 35°C to 45°C, which meets the use requirements of the diesel engine.

[0022] As Figure 3As shown, when the diesel engine is running at 75% to 100% load, i.e. high load, the pressure of the supercharged air is further increased, the supercharged air pushes the piston 53 in the control cylinder 5 to continue moving right to the position shown in the figure, at this time the compressed air passage 56 is in communication with the first compressed air outlet 581 and the second compressed air outlet 582 on the upper side of the control cylinder 5, the first four-way valve 2 and the second four-way valve 3 are both in communication, the outer interface 25 of the first four-way valve 2 is in communication with the lower interface 22, the upper interface 23 is in communication with the inner interface 24, the first upper interface 32 of the second four-way valve 3 is in communication with the first lower interface 34, and the second upper interface 33 is in communication with the second lower interface 35. The cooling water is divided into two paths, one path enters the second cooler 14 through the second four-way valve 3 to cool the supercharged air, after cooling, the water temperature rises to 29-40℃, enters the first cooler 13 through the first four-way valve 2 to cool the supercharged air again, and finally flows to the cooling water outlet pipe 8 through the second four-way valve 3; the other path enters the diesel engine 7 to cool various parts to 85℃, enters the first four-way valve 2 through the thermostat 9, and directly enters the cooling water outlet pipe 8. In this mode, the temperature of the supercharged air of the diesel engine before entering the supercharged air cooler 1 is above 200℃, and a large amount of cooling is required, after being cooled by the first cooler 13 and the second cooler 14, the temperature of the supercharged air can be reduced to 35-45℃, meeting the use requirements of the diesel engine.

[0023] In addition to the above-mentioned embodiments, the present application can also have other implementation manners, and any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope of the present application.

Claims

1. A marine diesel engine charge air cooling system, characterized by: The application relates to a turbocharged diesel engine cooling system, which comprises a turbocharger, a first four-way valve, a second four-way valve, a water pump and a control cylinder; the air inlet of the turbocharger is communicated with the air outlet of the turbocharger through a pipeline, the air outlet of the turbocharger is communicated with the air inlets of the diesel engine and the control cylinder through a pipeline, the lower side of the control cylinder is provided with a compressed air inlet, the first compressed air outlet on the upper side of the control cylinder is communicated with the air inlet of the first four-way valve through a pipeline, and the second compressed air outlet on the upper side of the control cylinder is communicated with the air inlet of the second four-way valve through a pipeline; the control cylinder comprises a cylinder body, a piston arranged in the cylinder body and a spring, the two ends of the piston are respectively provided with piston rings, the middle part of the piston is provided with a compressed air channel which penetrates the piston horizontally, and the two ends of the spring are respectively fixedly connected with one end of the piston and one end of the cylinder body; the lower interface of the first four-way valve is communicated with the water outlet pipe, the upper interface of the first four-way valve is communicated with the inlet of the first cooler in the turbocharger through a pipeline, the inner interface of the first four-way valve is communicated with the outlet of the second cooler in the turbocharger through a pipeline, and the outer interface of the first four-way valve is communicated with the outlet of the diesel engine cooling water system through a pipeline; the first upper interface of the second four-way valve is communicated with the outlet of the first cooler in the turbocharger, the second upper interface of the second four-way valve is communicated with the inlet of the second cooler in the turbocharger, the first lower interface of the second four-way valve is communicated with the water outlet pipe, and the second lower interface of the second four-way valve is communicated with the water inlet pipe; the first four-way valve and the second four-way valve are single-acting pneumatic butterfly valves; the water pump inlet is communicated with the water inlet pipe, and the water pump outlet is communicated with the inlet of the diesel engine cooling water system.

2. A marine diesel engine charge air cooling system as claimed in claim 1, characterised in that: A thermostatic valve is arranged on the pipeline between the outer interface of the first four-way valve and the outlet of the diesel engine cooling water system.

3. A marine diesel engine charge air cooling system as claimed in claim 2, characterised in that: The thermostatic valve is a wax type mechanical thermostatic valve, and the temperature control range is 80-85 DEG C.

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