Method and device for enhancing heat exchange capacity of water cavity in nose bridge area of cylinder cover of diesel engine

Abstract

The invention relates to a method and device for enhancing the heat exchange capacity of a diesel engine cylinder cover nose bridge area water cavity, and belongs to the technical field of energy power. According to the method, a disturbance device with a spiral structure is installed in a cylinder cover nose bridge area water cavity, water flow is promoted to be converted from laminar flow to turbulent flow, fluid mixing is enhanced, the boundary layer thickness is reduced, the flow speed is increased by reducing the circulation area, and therefore the heat exchange efficiency is remarkably improved. The disturbance device comprises a threaded installation structure and a spiral disturbance structure, is easy and convenient to install, good in sealing performance and suitable for a cooling system of a highly-strengthened diesel engine. The device effectively solves the problems of limited water pump lift, poor drilling cooling effect and the like in the prior art, and has the advantages of simple structure, low cost, remarkable heat exchange strengthening effect and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of energy power, and particularly relates to a method and device for enhancing the heat exchange capacity of a water cavity in the nose bridge area of a diesel engine cylinder head. BACKGROUND

[0002] With the continuous increase of engine power and explosion pressure, the heat load problem of the cylinder head is increasingly prominent, and the higher working temperature of the cylinder head affects the reliability and service life of the engine.

[0003] To reduce the working temperature of the cylinder head, it needs to be strengthened cooling, and the cylinder head of a high-strength diesel engine generally adopts water cooling. At present, the methods for improving the heat exchange capacity of the water-cooled cylinder head include the following several methods: a. as far as possible, a large head water pump is selected to improve the water supply speed; b. drilling cooling is adopted to strengthen the water flow rate in the nose bridge area of the cylinder head. However, the head of the diesel engine water pump has an upper limit, and simply increasing the head of the water pump has limited contribution to the local cooling strengthening of the cylinder head. The drilling cooling has a good effect on improving the local flow rate of the cylinder head, but the surface roughness of the drilling is low, the thickness of the heat exchange surface layer is increased, and it is not conducive to the surface solid-liquid surface convection heat exchange. SUMMARY

[0004] The present application provides a method and device for enhancing the heat exchange capacity of a water cavity in the nose bridge area of a diesel engine cylinder head, which solves the problems of limited water pump head, poor drilling cooling effect and the like in the prior art.

[0005] In order to solve the above technical problems, the present application provides a method for enhancing the heat exchange capacity of a water cavity in the nose bridge area of a diesel engine cylinder head, characterized in that: a disturbance device is installed in the water cavity in the nose bridge area of the cylinder head, the disturbance device promotes the flow state change of the water flow passing through the area, thereby enhancing the heat exchange capacity, and the flow state change includes promoting the transition of the water flow from laminar flow to turbulent flow, promoting the mixing of the boundary layer and the core area fluid, reducing the thickness of the boundary layer, and increasing the water flow rate by reducing the flow area.

[0006] Further, the disturbance device is fixed to the wall surface of the cylinder head water cavity by a threaded connection, and sealing glue is coated during installation to prevent leakage.

[0007] Further, one disturbance device is installed in each of the four nose bridge area regions.

[0008] A disturbance device for implementing the method, characterized in that: it comprises an installation structure (1) and a disturbance generation structure (2) connected as a whole, the installation structure (1) is used for threaded connection with the cylinder head; and the disturbance generation structure (2) is a spiral structure used for changing the flow direction of the water flow.

[0009] Further, the pitch, helix angle or thread depth of the spiral structure can be adjusted to adapt to different flow strengthening requirements.

[0010] Further, the disturbance device is made of heat-conducting material, further enhancing the local heat exchange effect.

[0011] A diesel engine cylinder head, characterized in that it comprises the disturbance device, which is installed in the water cavity of the nose bridge area of the cylinder head.

[0012] Further, four disturbance devices are arranged in the water cavity of the nose bridge area, respectively corresponding to the four nose bridge areas.

[0013] Further, the disturbance device is installed through a special threaded hole machined on the cylinder head.

[0014] A diesel engine, characterized in that it comprises the cylinder head according to any one of claims 7 to 9.

[0015] Beneficial effects: The invention installs bolts on the bottom plate water cavity side, forcing the water flow to spiral motion, improving the water cavity heat exchange capacity, and this method has the following advantages: a. Reducing the critical Reynolds number of water flow, promoting the transition of water flow from laminar flow to turbulent flow; b. Increasing the fluid disturbance in the near-wall region, promoting the mixing of the boundary layer and the core region fluid, reducing the boundary layer thickness; c. Reducing the water flow area, increasing the water flow velocity. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Laminar flow schematic diagram

[0017] Figure 2 Disturbance flow transition schematic diagram

[0018] Figure 3 Disturbance device

[0019] Figure 4 Disturbance device installation schematic

[0020] Figure 5 Disturbance device working schematic. DETAILED DESCRIPTION

[0021] To make the purpose, content and advantages of the present invention clearer, the specific embodiments of the present invention are described in further detail below.

[0022] The present invention proposes a method for strengthening the heat exchange capacity of the water cavity of the nose bridge area of the diesel engine cylinder head, which arranges a disturbance device near the wall surface of the cylinder head to promote the transition of the fluid flow state near the wall surface from laminar flow to turbulent flow, and strengthens the heat exchange capacity of the water cavity, as shown in Figure 1 and Figure 2 .

[0023] Specifically, the disturbance device is installed in the nose bridge area of the cylinder head to change the flow of the water in the nose bridge area.

[0024] The disturbance device is divided into two parts: disturbance device mounting structure 1 and disturbance occurrence structure 2 connected in turn;

[0025] The disturbance device mounting structure 1 is a common threaded connection structure for fixing the disturbance device on the cylinder head, and the disturbance occurrence structure 2 is a common threaded spiral structure, which promotes the spiral change of the flow direction of the water flow passing through the spiral structure.

[0026] Figure 4 The disturbance device installation schematic diagram involves the cylinder head 3, the cylinder head water cavity 4, the disturbance device A 5, the disturbance device B 6, the disturbance device C 7, and the disturbance device D 8.

[0027] Special threads are machined on the cylinder head, and the disturbance device common threads are connected therewith. In the working state, the cylinder head 3 has cooling water flowing in the cylinder head water cavity 2, and the key cooling area of the cooling water is in the nose bridge area.

[0028] The disturbance device A, the disturbance device B, the disturbance device C, and the disturbance device D are respectively installed in the four nose bridge areas, and the installation mode is threaded connection. During installation, glue is coated to strengthen sealing and avoid water leakage, so as to realize the change of the water flow in the nose bridge area and strengthen cooling.

[0029] As shown in Figure 5 , the cooling water flows through the nose bridge area, the disturbance device reduces the critical Reynolds number of the water flow, promotes the transition of the water flow in the nose bridge area from laminar flow to turbulent flow, promotes the mixing of the boundary layer and the core area fluid, reduces the boundary layer thickness, reduces the water flow area, and increases the water flow velocity. The disturbance device realizes the strengthened cooling of the nose bridge area of the cylinder head.

[0030] The present application has the advantages of simple structure, low cost, and remarkable heat exchange strengthening effect.

[0031] The above description is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should be regarded as the protection scope of the present application.

Claims

1. A method for enhancing the heat exchange capacity of the water cavity in the nose area of ​​a diesel engine cylinder head, characterized in that: A disturbance device is installed in the water cavity of the cylinder head nose area. The disturbance device causes the water flowing through the area to change its flow state, thereby enhancing the heat exchange capacity. The change in flow state includes promoting the water flow from laminar to turbulent flow, promoting the mixing of the boundary layer and the core fluid, reducing the boundary layer thickness, and increasing the water flow velocity by reducing the flow area.

2. The method according to claim 1, characterized in that: The disturbance device is fixed to the cylinder head water chamber wall by a threaded connection, and sealant is applied during installation to prevent leakage.

3. The method according to claim 1, characterized in that: Each of the four nasal bridge areas is equipped with a disturbance device.

4. A disturbance device for implementing the method of claim 1, characterized in that: It includes an integral mounting structure (1) and a disturbance generating structure (2), wherein the mounting structure (1) is used to be threadedly connected to the cylinder head; and the disturbance generating structure (2) is a spiral structure used to change the direction of water flow.

5. The disturbance device according to claim 4, characterized in that: The pitch, helix angle, or thread depth of the spiral structure are adjustable to adapt to different flow enhancement requirements.

6. The disturbance device according to claim 4 or 5, characterized in that: The disturbance device is made of thermally conductive material, which further enhances the local heat exchange effect.

7. A diesel engine cylinder head, characterized in that: Includes the disturbance device as described in any one of claims 4 to 6, wherein the disturbance device is installed in the water cavity of the cylinder head nose area.

8. The cylinder head according to claim 7, characterized in that: The nasal bridge area water cavity is equipped with four disturbance devices, each corresponding to one of the four nasal bridge areas.

9. The cylinder head according to claim 7 or 8, characterized in that: The disturbance device is installed through a special threaded hole machined on the cylinder head.

10. A diesel engine, characterized in that: Includes the cylinder head as described in any one of claims 7 to 9.

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