Engine cooling circulation system and working method thereof

Abstract

The invention relates to the technical field of engines, in particular to an engine cooling circulation system and a working method thereof, and the system comprises a low-temperature circulation system which comprises an air cooler and a heat exchanger; the air cooler provides cooling air for the engine, and the cooling medium is seawater and discharged out of the cabin through the heat exchanger. The high-temperature circulating system comprises lubricating oil circulation and cooling fresh water circulation, the lubricating oil circulation is composed of a lubricating oil cooler and an engine, and the cooling fresh water circulation is sequentially composed of a fresh water pump, the lubricating oil cooler, the engine, a temperature adjusting valve and a heat exchanger closed loop. If the water temperature in the temperature adjusting valve is too high, the valve is opened to enable cooling fresh water to flow into the heat exchanger to be cooled again, and high-temperature circulation is conducted again; if the water temperature in the temperature adjusting valve is lower than the set temperature, the bypass valve is opened to mix the cooling fresh water with the fresh water cooled by the heat exchanger and flow back to the fresh water pump; lubricating oil of the low-temperature circulating system is cooled and merged into the high-temperature circulating system, so that the problem of environmental pollution caused by leakage of the lubricating oil is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of engines, in particular to an engine cooling circulation system and a working method thereof. Background Art

[0002] The cooling system used by the existing 1.2MW engine for drilling platforms is divided into a low-temperature circulation system and a high-temperature circulation system. In the low-temperature circulation system, the seawater pump installed in the cabin pumps about 32℃ seawater into the air cooler, and the seawater then enters the shell and tube lubricating oil cooler installed in the cabin and the fresh water cooler installed in the cabin, and finally is discharged from the cabin; in the high-temperature circulation system, the high-temperature fresh water pump pumps about 75℃ cooling fresh water into the engine to cool the engine cylinder liner, and then about 85℃ cooling fresh water enters the fresh water cooler, and the cooling fresh water of about 85℃ is cooled to about 75℃ by about 37℃ seawater.

[0003] Among them, there is a risk of lubricating oil leakage in the lubricating oil cooler during the low-temperature circulation process. Since seawater is discharged from the cabin after passing through the lubricating oil cooler, the leaked lubricating oil will be discharged into the sea, causing seawater pollution. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an engine cooling circulation system and a working method thereof. The present invention integrates the lubricating oil cooling of the low-temperature circulation system into the high-temperature circulation system, thereby avoiding the problem of environmental pollution caused by the leakage of lubricating oil into the ocean. In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0005] In a first aspect, the present invention provides an engine cooling circulation system, comprising:

[0006] The low temperature circulation system includes an air cooler and a heat exchanger; the air cooler provides cooling air to the engine, and its cooling medium is seawater and is discharged from the cabin through the heat exchanger;

[0007] The high-temperature circulation system includes a lubricating oil circulation and a cooling fresh water circulation. The lubricating oil circulation is composed of a lubricating oil cooler and the engine. The cooling fresh water circulation is composed of a fresh water pump, the lubricating oil cooler, the engine, a thermostatic valve, and a heat exchanger closed loop in sequence.

[0008] As a further implementation, the thermostatic valve is provided with a bypass port and is connected to the fresh water pump via a bypass pipeline, and the return water pipeline of the heat exchanger is connected to the bypass pipeline.

[0009] As a further implementation, a water collecting main pipe is provided between the engine and the temperature regulating valve, and an air vent pipe is provided on the water collecting main pipe.

[0010] As a further implementation, the vent pipe is connected to an expansion water tank, which can replenish water to the cooling fresh water circulation, collect gas in the engine cooling fresh water, and automatically discharge it from the high-temperature circulation system.

[0011] As a further implementation, the expansion water tank is connected to the bypass pipeline by providing a water supply pipe.

[0012] As a further implementation, the low-temperature circulation system further includes a supercharger, and the supercharger provides pressurized air to the air cooler.

[0013] As a further implementation, the air cooler is equipped with a seawater pump for pumping seawater medium.

[0014] As a further implementation, the engine is connected to the supercharger via an exhaust pipe.

[0015] As a further implementation, the low-temperature circulation system and the high-temperature circulation system are both integrated on the engine.

[0016] In a second aspect, the present invention provides a working method of an engine cooling circulation system according to the first aspect, comprising the following steps:

[0017] In the low-temperature circulation system, seawater is pumped into the air cooler to cool the air. The cooled air enters the engine, while the seawater enters the heat exchanger and is discharged from the cabin.

[0018] The fresh water pump of the high-temperature circulation system pumps the cooling fresh water into the lubricating oil cooler, and then enters the engine after heat exchange in the lubricating oil cooler to cool the cylinder liners one by one, and finally flows back to the thermostatic valve; if the water temperature in the thermostatic valve is too high, the valve will be opened to allow the cooling fresh water to flow into the heat exchanger for further cooling, and then return to the fresh water pump after cooling to undergo high-temperature circulation again; if the water temperature in the thermostatic valve is lower than the set temperature, the bypass port will be opened to mix the cooling fresh water with the fresh water cooled by the heat exchanger and flow back to the fresh water pump, so as to achieve thermal balance of the cooling water circulation.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The present invention integrates the lubricating oil cooling of the low-temperature circulation system into the high-temperature circulation system, thus avoiding the problem of environmental pollution caused by the leakage of lubricating oil into the ocean. At the same time, it facilitates faster warm-up of the engine and solves the problem of low oil temperature that occurs during long-term low-load operation.

[0021] 2. The thermostatic valve provided in the present invention can adjust and control the temperature of the cooling water entering the engine. If the water temperature in the thermostatic valve is too high, the valve will be opened to allow the cooling fresh water to flow into the heat exchanger for re-cooling, and then return to the fresh water pump after cooling, and undergo the above-mentioned high-temperature cycle again. If the water temperature in the thermostatic valve is lower than the temperature set by the thermostatic valve, the bypass port will be opened to mix the cooling fresh water with the fresh water cooled by the heat exchanger and flow back to the fresh water pump, so as to achieve the thermal balance of the cooling water circulation.

[0022] 3. The present invention adds a vent pipe to the water main to discharge the gas into the expansion water tank, which can discharge the bubbles generated during the operation of the engine's high-temperature circulation system, reduce the risk of water pump cavitation and cylinder liner cavitation, improve the cooling effect, and improve the engine reliability; when the pressure in the expansion water tank reaches a predetermined pressure, the expansion water tank is automatically vented, and the cooling fresh water liquid at the bottom of the expansion water tank is timely added to the high-temperature circulation system to achieve the purpose of water replenishment.

[0023] 4. The supercharger provided in the present invention can provide pressurized air to the air cooler, and the seawater pump of the low-temperature circulation system pumps seawater into the air cooler to cool the pressurized high-temperature air, which can effectively increase the oxygen-containing intake density entering the engine.

[0024] 5. The low-temperature circulation system and the high-temperature circulation system of the present invention are both integrated on the engine, that is, the air cooler, heat exchanger, lubricating oil cooler, thermostatic valve, fresh water pump, expansion water tank and other components are all integrated on the engine, which effectively improves the overall integration of the engine, makes the engine more compact, solves the problem of engine installation space, and reduces the workload of on-site installation of the whole machine, making it convenient for users to install on-site, with a neat appearance, easy operation and installation, safety and reliability, and strong usability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 Schematic diagram of an engine cooling circulation system in an embodiment of the present invention.

[0027] Figure 2 It is a schematic diagram of the structure in which the engine cooling circulation system is integrated on the engine in an embodiment of the present invention.

[0028] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0029] Among them: 1. Air cooler; 2. Heat exchanger; 3. Lubricating oil cooler; 4. Temperature regulating valve; 5. Fresh water pump; 6. Expansion tank; 7. Engine; 8. Supercharger. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0031] Embodiment 1

[0032] In a typical embodiment of the present invention, reference is made to Figure 1 and Figure 2 As shown, an engine cooling circulation system includes a low-temperature circulation system and a high-temperature circulation system.

[0033] The low temperature circulation system includes an air cooler 1 and a heat exchanger 2. The air cooler 1 provides cooling air to the engine 7, and its cooling medium is seawater and is discharged from the cabin through the heat exchanger 2. The air cooler 1 is equipped with a seawater pump for pumping the seawater medium.

[0034] The low temperature circulation system also includes a supercharger 8, which provides pressurized air to the air cooler 1. The seawater pump of the low temperature circulation system pumps seawater at about 32°C into the air cooler 1 to cool the high temperature air after supercharging, which can effectively increase the oxygen-containing intake air density entering the engine 7. The cooled air enters the engine 7, and the seawater enters the heat exchanger 2 integrated on the engine 7 and is discharged from the cabin.

[0035] The engine 7 is connected to the supercharger 8 by setting an exhaust pipe. The supercharger 8 increases the intake volume by compressing air, and uses the inertial impact of the exhaust gas discharged by the engine 7 to drive the turbine in the turbine chamber. The turbine drives the coaxial impeller, and the impeller presses the air sent from the intake pipe to make it pressurized and enter the cylinder. When the speed of the engine 7 increases, the exhaust gas discharge speed and the turbine speed also increase synchronously. The impeller compresses more air into the cylinder. The increase in air pressure and density can burn more fuel, and the fuel amount is increased accordingly and the speed of the engine 7 is adjusted, thereby increasing the output power of the engine.

[0036] The functions of the supercharger 8 include increasing engine power, optimizing engine emissions, having plateau compensation functions, and enhancing fuel economy. Therefore, the supercharger 8 significantly improves the performance and efficiency of the engine 7 by increasing the intake pressure and flow rate, while reducing the negative impact on the environment.

[0037] The high temperature circulation system includes a lubricating oil circulation and a cooling fresh water circulation. The lubricating oil circulation is composed of a lubricating oil cooler 3 and an engine 7, and the cooling fresh water circulation is composed of a fresh water pump 5, a lubricating oil cooler 3, an engine 7, a thermostatic valve 4, and a heat exchanger 2 in a closed loop.

[0038] In this embodiment, the cooling water of the lubricating oil cooler 3 is cooled by fresh water cooled by a high-temperature circulation system. The lubricating oil cooler 3 adopts a plate-type structure and is integrated into the engine.

[0039] This embodiment integrates the lubricating oil cooling of the low-temperature circulation system into the high-temperature circulation system, thereby avoiding the problem of environmental pollution caused by the leakage of lubricating oil into the ocean. At the same time, it facilitates faster engine warm-up and solves the problem of low oil temperature during long-term low-load operation.

[0040] This embodiment designs the temperature of the fresh water entering the engine for cooling to be ≥70° C. through theoretical calculation, which can ensure that the fresh water entering the engine for cooling will not cause the cylinder liner to cavitate too quickly.

[0041] The flow rate of cooling fresh water is calculated by the heat exchange of lubricating oil cooler 3, so as to ensure that the temperature of cooling fresh water reaches the expected temperature after entering the lubricating oil cooler for heat exchange. The cooling fresh water entering the engine 7 is in a closed circulation system, and the lubricating oil in the lubricating oil cooler 3 exchanges heat with the cooling fresh water, and the lubricating oil pressure of the lubricating oil cooler 3 is greater than the cooling fresh water.

[0042] The thermostatic valve 4 is provided with a bypass port and is connected to the fresh water pump 5 through a bypass pipeline, and the return water pipeline of the heat exchanger 2 is connected to the bypass pipeline.

[0043] The function and role of the thermostatic valve 4 is to adjust and control the temperature of the cooling water entering the engine 7. If the water temperature in the thermostatic valve 4 is too high, the valve will be opened to allow the cooling fresh water to flow into the heat exchanger 2 for re-cooling, and then return to the fresh water pump 5 after cooling, and undergo the above high-temperature cycle again. If the water temperature in the thermostatic valve 4 is lower than the temperature set by the thermostatic valve 4, the bypass valve will be opened to mix the cooling fresh water with the fresh water cooled by the heat exchanger 2 and flow back to the fresh water pump 5, so as to achieve thermal balance of the cooling water circulation.

[0044] In this embodiment, a water collecting main pipe is provided between the engine 7 and the thermostatic valve 4, and a vent pipe is provided on the water collecting main pipe. The vent pipe is connected to an expansion water tank 6, which can replenish water to the cooling fresh water circulation, collect gas in the engine cooling fresh water, and automatically discharge it from the high-temperature circulation system. The expansion water tank 6 is connected to the bypass pipeline by providing a water replenishment pipe.

[0045] Bubbles are generated during the operation of the engine 7. In order to reduce the risk of water pump cavitation and cylinder liner cavitation, improve the cooling effect and increase the reliability of the engine, a vent pipe is added to the water main to discharge the gas into the expansion water tank 6. The expansion water tank 6 is provided with a pressure limiting valve. When the pressure in the expansion water tank 6 reaches a predetermined pressure, the expansion water tank is automatically vented, and the cooling fresh water liquid at the bottom of the expansion water tank 6 is added to the cooling circulation system in time.

[0046] The low-temperature circulation system and the high-temperature circulation system are both integrated on the engine 7, that is, the air cooler 1, the heat exchanger 2, the lubricating oil cooler 3, the thermostatic valve 4, the fresh water pump 5, the expansion water tank 6 and other components are all integrated on the engine, which effectively improves the overall integration of the engine, makes the engine more compact, solves the problem of engine installation space, and reduces the workload of on-site installation of the whole machine, making it convenient for users to install on-site, with a neat appearance, easy operation and installation, safety, reliability and strong usability.

[0047] The technical solution of this embodiment plays a key guiding role in the overall layout and cooling strategy of the cooling system of an in-line engine with a displacement of 35L to 70L. It plays a leading role in the market sales of engines of similar products in the existing market and in the future, and in improving the reliability, safety and operability of the engine, which is conducive to improving user experience.

[0048] Embodiment 2

[0049] This embodiment provides a working method of an engine cooling circulation system, comprising the following steps:

[0050] The seawater pump of the low-temperature circulation system pumps seawater at about 32°C into the air cooler 1 to cool the high-temperature pressurized air, which can effectively increase the oxygen-containing intake density entering the engine 7. The cooled air enters the engine 7, and the seawater enters the heat exchanger 2 integrated on the engine 7 and is discharged from the cabin.

[0051] The fresh water pump 5 of the high temperature circulation system pumps cooling fresh water of about 75°C into the lubricating oil cooler 3 to cool the lubricating oil inside the lubricating oil cooler 3. After entering the lubricating oil cooler 3 for heat exchange, the temperature of the cooling fresh water reaches the expected temperature (70°C), and then the cooling fresh water enters the engine 7. After the fresh water enters the engine 7, it cools the cylinder sleeves of the engine 7 one by one through the water collection main pipe, and finally flows back to the thermostatic valve 4. If the water temperature in the thermostatic valve 4 is too high (higher than 65°C), the valve will be opened to flow the cooling fresh water into the heat exchanger 2 for further cooling, and then return to the fresh water pump 5 after cooling, and experience the above high temperature cycle again. If the water temperature in the thermostatic valve 4 is lower than the temperature set by the thermostatic valve 4 (65°C), the bypass valve will be opened to mix the cooling fresh water with the fresh water cooled by the heat exchanger 2 and flow back to the fresh water pump 5, so as to achieve the thermal balance of the cooling water circulation.

[0052] Bubbles are generated during the operation of the engine 7. In order to reduce the risk of water pump cavitation and cylinder liner cavitation, improve the cooling effect and increase the reliability of the engine, a vent pipe is added to the water main to discharge the gas into the expansion water tank 6. The expansion water tank 6 is provided with a pressure limiting valve. When the pressure in the expansion water tank 6 reaches a predetermined pressure, the expansion water tank is automatically vented, and the cooling fresh water liquid at the bottom of the expansion water tank 6 is added to the cooling circulation system in time.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An engine cooling circulation system, characterized in that: include: The low temperature circulation system includes an air cooler and a heat exchanger; the air cooler provides cooling air to the engine, and its cooling medium is seawater and is discharged from the cabin through the heat exchanger; The high-temperature circulation system includes a lubricating oil circulation and a cooling fresh water circulation. The lubricating oil circulation is composed of a lubricating oil cooler and the engine. The cooling fresh water circulation is composed of a fresh water pump, the lubricating oil cooler, the engine, a thermostatic valve, and a heat exchanger closed loop in sequence.

2. An engine cooling circulation system according to claim 1, characterized in that: The temperature regulating valve is provided with a bypass port and is communicated with the fresh water pump through a bypass pipeline, and the return water pipeline of the heat exchanger is connected to the bypass pipeline.

3. An engine cooling circulation system according to claim 2, characterized in that: A water collecting main pipe is arranged between the engine and the temperature regulating valve, and an air venting pipe is arranged on the water collecting main pipe.

4. An engine cooling circulation system according to claim 3, characterized in that: The vent pipe is connected to an expansion water tank, which can replenish water to the cooling fresh water circulation, collect gas in the engine cooling fresh water, and automatically discharge it from the high-temperature circulation system.

5. An engine cooling circulation system according to claim 4, characterized in that: The expansion water tank is connected to the bypass pipeline by providing a water supply pipe.

6. The engine cooling circulation system according to claim 1, characterized in that: The low temperature cycle system further includes a supercharger, which provides pressurized air to the air cooler.

7. An engine cooling circulation system according to claim 6, characterized in that: The air cooler is equipped with a seawater pump for pumping seawater medium.

8. An engine cooling circulation system according to claim 6, characterized in that: The engine is communicated with the supercharger via an exhaust pipe.

9. The engine cooling circulation system according to claim 1, characterized in that: The low-temperature circulation system and the high-temperature circulation system are both integrated on the engine.

10. A method for operating an engine cooling circulation system according to any one of claims 1 to 9, characterized in that: The following steps are involved: In the low-temperature circulation system, seawater is pumped into the air cooler to cool the air. The cooled air enters the engine, while the seawater enters the heat exchanger and is discharged from the cabin. The fresh water pump of the high-temperature circulation system pumps the cooling fresh water into the lubricating oil cooler, and then enters the engine after heat exchange in the lubricating oil cooler to cool the cylinder liners one by one, and finally flows back to the thermostatic valve; if the water temperature in the thermostatic valve is too high, the valve will be opened to allow the cooling fresh water to flow into the heat exchanger for further cooling, and then return to the fresh water pump after cooling to undergo high-temperature circulation again; if the water temperature in the thermostatic valve is lower than the set temperature, the bypass port will be opened to mix the cooling fresh water with the fresh water cooled by the heat exchanger and flow back to the fresh water pump, so as to achieve thermal balance of the cooling water circulation.

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