A high-power diesel engine cooling system double-expansion water tank pressure balancing device

Abstract

The present application relates to a kind of high-power diesel engine cooling system double expansion water tank pressure balancing device, belong to diesel engine cooling system technical field, solve the problem of water pump blade cavitation and coolant loss caused by the pressure imbalance of diesel engine cooling liquid system in prior art.The present application includes: water pump, radiator, small circulation pipeline and large circulation pipeline;The small circulation pipeline is provided with first expansion water tank;The large circulation pipeline is provided with second expansion water tank;Pressure balancing pipe is connected between the first expansion water tank and the second expansion water tank;The pressure balancing pipe is used to balance the pressure difference between the first expansion water tank and the second expansion water tank.The present application realizes the pressure balance in double expansion water tank, avoids the problem of water pump blade cavitation and coolant loss.

Description

Technical Field

[0001] This invention relates to the field of diesel engine cooling system technology, and in particular to a pressure balancing device for a dual expansion tank in a high-power diesel engine cooling system. Background Technology

[0002] The cooling system is a crucial component of a diesel engine, its primary function being to ensure the engine operates reliably and normally at the optimal temperature under complex working conditions. As diesel engine power increases, so does its heat dissipation capacity. High-power diesel engines, especially those exceeding 500kW, typically employ independently arranged radiators. The radiator is positioned a considerable distance from the engine, and traditional single-expansion tank cooling systems cannot meet the heat dissipation requirements of high-power diesel engines.

[0003] The cooling system mainly consists of an expansion tank, engine water circuit, water pump, radiator, thermostat, and connecting water pipes. The expansion tank's primary function is to create a closed-loop cooling system, providing space for expansion and steam condensation. It also regulates the pressure within the cooling system, ensuring stable operation, guaranteeing the system reaches its designed operating temperature, and preventing premature boiling. The expansion tank is typically located at the highest point of the cooling system.

[0004] The existing solutions mainly include:

[0005] 1. Large-volume expansion tank: This involves increasing the volume of the expansion tank and placing it between the diesel engine and radiator to meet the water circulation requirements of both. Its main disadvantages are: the large size of the expansion tank makes system layout difficult; furthermore, the expansion tank needs to be positioned close to the center of the diesel engine and radiator, while high-power diesel engines and radiators are typically located in separate spaces, making the placement of the expansion tank even more challenging.

[0006] 2. Dual independent expansion tanks, meaning the diesel engine and radiator are each equipped with independent expansion tanks. The advantage is that it can meet the cooling requirements of high-power diesel engine cooling systems and facilitates system layout.

[0007] Its main drawback is:

[0008] The dual expansion tanks form a communicating vessel structure through the radiator pipes. After the diesel engine has been running for a period of time, the thermostat opens, the large circulation is activated, and the diesel engine coolant and internal gases are injected into the first expansion tank through the diesel engine vent pipe under the action of the water pump. The air pressure in the upper part of the first expansion tank increases, which will squeeze the coolant into the second expansion tank. Conversely, the gas in the second expansion tank will enter the first expansion tank along the cooling pipes, thereby lowering the liquid level in the first expansion tank and raising the liquid level in the second expansion tank.

[0009] On the one hand, when the liquid level in the first expansion tank is too low, the pressure at the pump inlet is lower than the vaporization pressure of the coolant at that temperature. As a result, a large amount of gas dissolved in the coolant will overflow from the coolant, forming many small bubbles of steam and gas mixture, which will cause cavitation of the pump blades. On the other hand, when the liquid level in the second expansion tank is too high, the coolant will flow out from the drain pipe under the pressure cover, causing economic losses.

[0010] Therefore, based on the existing diesel engine cooling system, the following problems need to be solved:

[0011] 1. The problem that a single expansion tank in the cooling system of a high-power diesel engine cannot meet the requirements of a high-power diesel engine and a high-power radiator;

[0012] 2. The internal pressure of the dual independent expansion tanks in the cooling system of high-power diesel engines is unbalanced, which can cause water pump blades to be prone to cavitation and coolant to overflow. Summary of the Invention

[0013] Based on the above analysis, the present invention aims to provide a pressure balancing device for a dual expansion tank in a high-power diesel engine cooling system, in order to solve the problems of water pump blade cavitation and coolant loss caused by pressure imbalance in existing diesel engine coolant systems.

[0014] The objective of this invention is mainly achieved through the following technical solutions:

[0015] A pressure balancing device with dual expansion tanks for a high-power diesel engine cooling system includes: a water pump, a radiator, a small circulation pipeline and a large circulation pipeline; the small circulation pipeline is equipped with a first expansion tank; and the large circulation pipeline is equipped with a second expansion tank.

[0016] Furthermore, the small circulation pipeline includes: a first liquid filling pipe, a diesel engine vent pipe, a thermostat, and a compensation pipe; the thermostat is connected to the liquid outlet of the diesel engine, and the liquid inlet of the diesel engine is connected to the water pump; the compensation pipe connects the thermostat and the water pump.

[0017] Furthermore, one end of the first liquid filling pipe is connected to the water pump, and the other end is connected to the first expansion tank.

[0018] Furthermore, the diesel engine vent pipe connects to the upper space of the first expansion tank and the thermostat.

[0019] Furthermore, the first filling pipe is used to circulate coolant; a proportional regulating valve is provided on the first filling pipe.

[0020] Furthermore, the large circulation pipeline includes: a radiator, a second liquid filling pipe, a second expansion tank, a radiator vent pipe, a first flow pipe, and a second flow pipe.

[0021] Furthermore, the radiator is connected to the thermostat via a first flow pipe; the radiator is connected to the water pump via a second flow pipe.

[0022] Furthermore, the second expansion tank is connected to the radiator via a second liquid filling pipe.

[0023] Furthermore, the upper space of the second expansion tank is connected to the radiator via a radiator vent pipe.

[0024] Furthermore, a pressure balancing pipe is connected between the first expansion tank and the second expansion tank; the pressure balancing pipe is used to balance the pressure difference between the first expansion tank and the second expansion tank.

[0025] Furthermore, a solenoid valve is installed on the pressure balancing pipe, and the connection or disconnection of the pressure balancing pipe can be controlled by adjusting the opening and closing of the solenoid valve.

[0026] A method for balancing the pressure of a diesel engine coolant system, employing the aforementioned pressure balancing device for a dual expansion tank in a high-power diesel engine cooling system, includes the following steps:

[0027] Step S1: The controller detects the temperature status of the thermostat;

[0028] Step S2: Determine whether the thermostat is open based on the thermostat temperature;

[0029] When the thermostat temperature is lower than the thermostat opening temperature, the thermostat is in the closed state, and it is determined that the diesel engine is in the small circulation state. The controller reads the internal pressure signal PA of the first expansion tank.

[0030] When the thermostat temperature is higher than or equal to the thermostat opening temperature, the thermostat is in the open state, indicating that the diesel engine is in the large circulation state; at this time, the controller controls the proportional valve to be fully open, and at the same time detects and reads the pressure PB inside the second expansion tank.

[0031] Step S3: When the thermostat is closed, adjust the opening of the proportional valve according to the pressure status of the first expansion tank and the second expansion tank; when the thermostat is open, control the opening or closing of the solenoid valve according to the pressure status of the first expansion tank and the second expansion tank.

[0032] The technical solution of this invention can achieve at least one of the following effects:

[0033] The dual expansion tank pressure balancing device of the present invention achieves pressure balance inside the dual expansion tanks by connecting a pressure balancing pipe between the first expansion tank and the second expansion tank.

[0034] The dual expansion tank pressure balancing device of the present invention adjusts the opening degree of the proportional valve and the opening and closing of the solenoid valve according to the opening state of the thermostat and the pressure state of the dual expansion tanks, thereby regulating the pressure in the first expansion tank and the second expansion tank.

[0035] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0036] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0037] Figure 1 This invention relates to a pressure balancing device for a dual expansion tank in a high-power diesel engine cooling system.

[0038] Figure 2 This refers to the small circulation pipeline of the dual expansion tank pressure balancing device of the present invention;

[0039] Figure 3 This refers to the large circulation pipeline of the dual expansion tank pressure balancing device of the present invention;

[0040] Figure 4 This is a control flowchart of the dual expansion tank pressure balancing device of the present invention.

[0041] Figure label:

[0042] 1. Diesel engine; 2. Water pump; 3. Radiator; 4-1. First filler pipe; 4-2. Second filler pipe; 5. Radiator vent pipe; 6. Pressure cap; 7-1. First expansion tank; 7-2. Second expansion tank; 8. Diesel engine vent pipe; 9. Thermostat; 10. Compensation pipe; 11. Solenoid valve; 12. Pressure balance pipe; 13. Proportional regulating valve; 14. Controller; 15. First flow pipe; 16. Second flow pipe. Detailed Implementation

[0043] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0044] Example 1

[0045] like Figure 1As shown in the figure, a specific embodiment of the present invention provides a dual expansion tank pressure balancing device for a high-power diesel engine cooling system, comprising: a water pump 2, a radiator 3, a small circulation pipe and a large circulation pipe; the small circulation pipe is provided with a first expansion tank 7-1; the large circulation pipe is provided with a second expansion tank 7-2; a pressure balancing pipe 12 is connected between the first expansion tank 7-1 and the second expansion tank 7-2; the pressure balancing pipe 12 is used to balance the pressure difference between the first expansion tank 7-1 and the second expansion tank 7-2.

[0046] Specifically, such as Figure 2 As shown, the small circulation pipeline includes: a first liquid filling pipe 4-1, a diesel engine vent pipe 8, a thermostat 9, and a compensation pipe 10.

[0047] The outlet of the diesel engine 1 is connected to the thermostat 9, and the inlet of the diesel engine 1 is connected to the water pump 2. A compensating pipe 10 is connected between the thermostat 9 and the water pump 2.

[0048] Specifically, one end of the first liquid filling pipe 4-1 is connected to the water pump 2, and the other end is connected to the first expansion tank 7-1; the diesel engine vent pipe 8 connects the upper space of the first expansion tank 7-1 and the thermostat 9.

[0049] Specifically, the first liquid inlet pipe 4-1 is used for the flow of coolant.

[0050] Specifically, a proportional regulating valve 13 is provided on the first liquid addition pipe 4-1.

[0051] Specifically, such as Figure 3 As shown, the large circulation pipeline includes: radiator 3, second liquid filling pipe 4-2, second expansion tank 7-2, radiator vent pipe 5, first flow pipe 15, and second flow pipe 16.

[0052] The outlet of the diesel engine 1 is connected to the thermostat 9, the inlet of the diesel engine 1 is connected to the water pump 2, the thermostat 9 is connected to the inlet of the radiator 3 through the first flow pipe 15, and the outlet of the radiator 3 is connected to the water pump 2 through the second flow pipe 16.

[0053] Specifically, the flow path of the coolant in the large circulation is as follows: the coolant flows out from the outlet of the diesel engine 1 and enters the thermostat 9. After passing through the thermostat 9, it enters the radiator 3 through the first flow pipe 15 for heat dissipation. After being cooled by the radiator 3, the coolant flows into the second flow pipe 16 and is pumped into the diesel engine 1 by the water pump 2 to cool the diesel engine 1.

[0054] Specifically, the second expansion tank 7-2 is connected to the radiator 3 via the second liquid filling pipe 4-2.

[0055] Specifically, the upper space of the second expansion tank 7-2 is connected to the radiator 3 through the radiator vent pipe 5.

[0056] Furthermore, a first pressure sensor is installed in the first expansion tank 7-1 to monitor the internal pressure PA of the first expansion tank 7-1; a second pressure sensor is installed in the second expansion tank 7-2 to monitor the internal pressure PB of the second expansion tank 7-2.

[0057] Example 2

[0058] A specific embodiment of the present invention provides a method for balancing the pressure of a diesel engine coolant system, such as... Figure 4 As shown, the pressure of the first expansion tank 7-1 and the second expansion tank 7-2 of the dual expansion tank pressure balancing device for a high-power diesel engine cooling system in Example 1 is balanced.

[0059] like Figure 4 As shown, the pressure balancing method described above includes the following steps:

[0060] Step S1: The controller detects the temperature status of the thermostat 9;

[0061] Step S2: Determine whether thermostat 9 is open based on its temperature;

[0062] When the temperature of thermostat 9 is lower than the opening temperature of thermostat 9, thermostat 9 is in the closed state, and it is determined that the diesel engine is in the small circulation state; at this time, after the controller 14 closes the solenoid valve 11, the controller 14 reads the internal pressure signal PA of the first expansion tank 7-1.

[0063] When the temperature of thermostat 9 is higher than or equal to the opening temperature of thermostat 9, thermostat 9 is in the open state, and it is determined that the diesel engine is in the large circulation state; at this time, the controller 14 controls the proportional valve 13 to be fully open, and at the same time detects and reads the pressure PB inside the second expansion tank 7-2.

[0064] Step S3: When the thermostat 9 is closed, the controller 14 adjusts the opening of the proportional valve 13 according to the pressure status of the first expansion tank 7-1 and the second expansion tank 7-2; when the thermostat 9 is open, the controller controls the solenoid valve 11 to open or close according to the pressure status of the first expansion tank 7-1 and the second expansion tank 7-2.

[0065] Among them, the solenoid valve 11 is opened or closed by the controller 14, and the proportional regulating valve 13 is controlled by the controller 14 to adjust the opening angle.

[0066] Step S31: When the diesel engine is just started or has been running for a short time, the diesel engine temperature is low, the thermostat 9 is closed, and the diesel engine coolant flows in the small circulation.

[0067] like Figure 2 As shown, the small circulation is as follows: after the coolant flows out of the diesel engine 1, it enters the compensating pipe 10 through the thermostat 9, and then re-enters the diesel engine 1 through the water pump 2. At this time, the coolant can enter the first expansion tank 7-1 from the water pump 2 through the first filler pipe 4-1, and a proportional valve 13 is installed on the first filler pipe 4-1. The coolant does not flow into the radiator 3, reducing heat loss and allowing the diesel engine 1 to heat up to the suitable temperature range as quickly as possible.

[0068] In step S31, when the controller 14 detects that the temperature of the thermostat 9 is lower than the opening temperature of the thermostat 9, it determines that the diesel engine is in a small circulation state. After the controller 14 controls the solenoid valve 11 to close, the controller 14 further reads the internal pressure signal of the first expansion tank 7-1.

[0069] A) Step S311:

[0070] When the internal pressure PA of the first expansion tank is greater than the internal pressure PB of the second expansion tank: the controller 14 adjusts the proportional valve 13 to reduce the opening angle and increase the friction resistance of the first liquid filling pipe 4-1, thereby preventing the liquid level in the second expansion tank 7-2 from being too high and avoiding coolant overflow.

[0071] B) Step S312:

[0072] When the internal pressure PA of the first expansion tank is less than the internal pressure PB of the second expansion tank: the controller 14 adjusts the proportional valve 13 to increase the opening angle to prevent water shortage in the first expansion tank 7-1 and water pump cavitation. The controller adopts PID feedback control to dynamically adjust the opening angle of the proportional valve 13.

[0073] Step S32: After the diesel engine has been running for a while, the diesel engine temperature rises, and the thermostat 9 opens after reaching the opening temperature, allowing the diesel engine coolant to flow in the large circulation.

[0074] like Figure 3 As shown, the large circulation is as follows: after the coolant flows out of the diesel engine 1, it passes through the thermostat 9 and enters the radiator 3. After passing through the radiator 3, it enters the water pump 2 and returns to the diesel engine 1, thereby enhancing the engine's heat dissipation and ensuring the engine can meet its heat dissipation balance requirements. At this time, the coolant can enter the first expansion tank 7-1 through the first filler pipe 4-1, and simultaneously enter the second expansion tank 7-2 through the second filler pipe 4-2. Furthermore, a pressure balance pipe 12 connects the first expansion tank 7-1 and the second expansion tank 7-2, allowing the coolant to flow between the two expansion tanks.

[0075] When controller 14 detects that the temperature of thermostat 9 is higher than or equal to the opening temperature of thermostat 9, it determines that the diesel engine is in the large circulation state. At this time, controller 14 controls proportional valve 13 to fully open, and simultaneously detects and reads the internal pressure of the first expansion tank 7-1 and the second expansion tank 7-2.

[0076] A) Step S321:

[0077] When the internal pressure PA of the first expansion tank is detected to be higher than the internal pressure PB of the second expansion tank, the solenoid valve 11 will be opened automatically, and the coolant will be replenished from the first expansion tank 7-1 to the second expansion tank 7-2, so that the internal pressure of the first expansion tank 7-1 and the second expansion tank 7-2 are balanced, and the coolant level is balanced.

[0078] B) Step S322:

[0079] When the internal pressure PA of the first expansion tank 7-1 is detected to be lower than the internal pressure PB of the second expansion tank 7-2: the solenoid valve 11 is closed, cutting off the flow of coolant between the first expansion tank 7-1 and the second expansion tank 7-2. The coolant is then replenished to the first expansion tank 7-1 by the water pump 2 through the first filling pipe 4-1. This prevents water pump blade cavitation and coolant overflow, ensuring the normal operation of the diesel engine cooling system.

[0080] When the liquid level in the first expansion tank is too low, the pressure at the pump inlet is lower than the vaporization pressure of the coolant at that temperature. This causes a large amount of gas dissolved in the coolant to overflow, forming numerous small bubbles of steam and gas, which in turn leads to cavitation of the pump blades. Using the pressure balancing method of this embodiment, when the internal pressure PA of the first expansion tank 7-1 is too low, the solenoid valve 11 is closed, allowing coolant to enter the first expansion tank 7-1 through the first filling pipe 4-1. This effectively prevents backflow of air bubbles within the tank. Even if air bubbles are generated in the first expansion tank 7-1, the filling state of the first filling pipe 4-1 ensures that the internal liquid flow is from the pump 2 to the first expansion tank 7-1, effectively preventing air bubbles from entering the pump 2 and thus effectively avoiding cavitation of the pump 2 blades.

[0081] Compared with existing technologies, the dual expansion tank cooling system with pressure balancing device provided in this embodiment can meet the needs of high-power diesel engines and high-power radiators, and its structure is simple and easy to arrange. At the same time, the automatic pressure balancing inside the dual expansion tanks can prevent cavitation of the diesel engine water pump blades and prevent coolant overflow, avoiding unnecessary economic losses.

[0082] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A pressure balancing device for a dual expansion tank cooling system of a high-power diesel engine, characterized in that, include: Water pump (2), radiator (3), small circulation pipeline and large circulation pipeline; the small circulation pipeline is equipped with a first expansion tank (7). 1); The large circulation pipeline is equipped with a second expansion tank (7). 2); First expansion tank (7) 1) and the second expansion tank (7) 2) Connect the pressure balance pipe (12) between them, the pressure balance pipe (12) is used to balance the first expansion tank (7) 1) and the second expansion tank (7) 2) The pressure difference between them; The small circulation pipeline includes: a first filling pipe (4-1), a diesel engine vent pipe (8), a thermostat (9), and a compensation pipe (10); the thermostat (9) is connected to the outlet of the diesel engine (1), and the inlet of the diesel engine (1) is connected to the water pump (2); the compensation pipe (10) connects the thermostat (9) and the water pump (2); the first filling pipe (4-1) 1) One end is connected to the water pump (2), and the other end is connected to the first expansion tank (7). 1); The diesel engine vent pipe (8) is connected to the first expansion tank (7). 1) the upper space and the thermostat (9), the first liquid filling pipe (4) 1) Used for circulating coolant; the first liquid inlet pipe (4 1) A proportional regulating valve (13) is provided on it; A solenoid valve (11) is installed on the pressure balance pipe (12). When the controller detects that the temperature of the thermostat (9) is higher than or equal to the opening temperature of the thermostat (9), it determines that the diesel engine is in the large circulation state. The controller (14) controls the proportional regulating valve (13) to be fully opened, and at the same time detects and reads the internal pressure of the first expansion tank (7-1) and the second expansion tank (7-2). When the first expansion tank (7) is detected 1) The internal pressure PA of the expansion tank is higher than that of the second expansion tank (7). 2) When the internal pressure PB: the solenoid valve (11) will be automatically opened, and the coolant will flow from the first expansion tank (7). 1) Replenish to the second expansion tank (7) In 2), the first expansion tank (7) is made so that 1) with the second expansion tank (7) 2) Internal pressure balance, the coolant level is balanced; when the first expansion tank (7) is detected... 1) The internal pressure PA is lower than that of the second expansion tank (7) When the internal pressure PB of 2) is reached: close the solenoid valve (11) and shut off the first expansion tank (7). 1) and the second expansion tank (7) 2) The coolant flows between the water pump (2) and the first liquid filling pipe (4). 1) Replenish to the first expansion tank (7) 1) In order to prevent cavitation of the pump blades.

2. The pressure balancing device for a dual expansion tank cooling system of a high-power diesel engine according to claim 1, characterized in that, The large circulation pipeline includes: a radiator (3), a second liquid filling pipe (4) 2) Second expansion tank (7 2) Radiator vent pipe (5), first flow pipe (15) and second flow pipe (16).

3. The pressure balancing device for a dual expansion tank cooling system of a high-power diesel engine according to claim 2, characterized in that, The radiator (3) is connected to the thermostat (9) through the first flow pipe (15); the radiator (3) is connected to the water pump (2) through the second flow pipe (16).

4. The pressure balancing device for a dual expansion tank cooling system of a high-power diesel engine according to claim 3, characterized in that, The second expansion tank (7) 2) Through the second liquid addition tube (4) 2) Connect to the radiator (3).

5. A pressure balancing device for a dual expansion tank cooling system of a high-power diesel engine according to claim 4, characterized in that, The second expansion tank (7) The upper space of 2) is connected to the radiator (3) through the radiator vent pipe (5).

6. A method for pressure balancing a diesel engine coolant system, characterized in that, Using claim 1 5. The pressure balancing device for the dual expansion tanks of the high-power diesel engine cooling system, as described in any one of the claims, performs pressure balancing of the dual expansion tanks; including the following steps: Step S1: The controller detects the temperature status of the thermostat (9); Step S2: Determine whether the thermostat (9) is open based on the temperature of the thermostat (9); Step S3: When the thermostat (9) is closed, according to the first expansion tank (7) 1) and the second expansion tank (7) 2) Adjust the opening degree of the proportional regulating valve (13) according to the pressure state; when the thermostat (9) is open, according to the first expansion tank (7) 1) and the second expansion tank (7) 2) The pressure state controls the opening or closing of the solenoid valve (11).

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