A boat engine cooling system and control method

Abstract

The present invention discloses a boat engine cooling system and a control method, belonging to the technical field of engine cooling, and solving the technical problem that the existing boat cooling system is not fine enough in controlling engine cooling. The system includes a controller, a cooling pipe, and a first temperature sensor. The cooling pipe includes an inlet section, a middle section, and a heat dissipation section. A second temperature sensor is provided at the inlet section. A first cooling shell is provided around the middle section. A jet nozzle and a first drain port are provided inside the first cooling shell. The jet nozzle is connected to an intelligent pump. A second cooling shell is provided around the heat dissipation section. The second cooling shell is provided with a water inlet and a second drain port. Intelligent valves are provided at both the water inlet and the second drain port. The water inlet is connected to a water pump. A third temperature sensor is provided at the outlet of the heat dissipation section. A fourth temperature sensor is provided at the second drain port. The controller is electrically connected to the intelligent pump, the intelligent valves, the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of engine cooling, and more specifically, it relates to a boat engine cooling system and a control method therefor. Background Art

[0002] An engine generally uses an internal combustion engine, which generates work by the heat energy generated by combustion. However, the effective power is only 30% - 40% of the total energy of the fuel, and the remaining energy is dissipated as exhaust heat loss and mechanical friction heat loss, thereby releasing a large amount of heat and increasing the engine temperature. An excessively high engine temperature may cause a reduction in the air charge in the cylinder and abnormal combustion, a decrease in engine power or poor fuel economy, and problems such as pre-ignition and knocking are likely to occur in gasoline engines. Therefore, it is necessary to cool various parts of the internal combustion engine.

[0003] Compared with an automobile that finally exchanges heat with air, the heat exchange efficiency is lower and the air is more affected by environmental factors. As the carrier of a high-speed boat, water is both a good and natural heat exchange medium, and its heat exchange efficiency is also better than that of air cooling.

[0004] Patent CN210660286U discloses a seawater cooling system for a ship engine. This cooling system controls the opening degree of a first electronic throttle valve according to the water temperature, oil temperature, and intake air temperature of the engine, thereby controlling the flow rate of the cooling water entering the engine. This cooling system only controls the opening degree of a single first electronic throttle valve, and the control is not delicate enough, resulting in a large fluctuation in the coolant temperature of the engine. Summary of the Invention

[0005] The technical problem to be solved by the present invention is in view of the above-mentioned deficiencies of the prior art. The first object of the present invention is to provide a boat engine cooling system.

[0006] The second object of the present invention is to provide a control method for a boat engine cooling system.

[0007] To achieve the first above-mentioned object, the present invention provides a cooling system for a boat engine, which includes a controller, a cooling pipe connected to the engine coolant return circuit, and a first temperature sensor for detecting the temperature of the external water source. The cooling pipe includes an inlet section, an intermediate section, and a heat dissipation section connected in sequence. The inlet section is provided with a second temperature sensor. A first cooling shell is provided around the intermediate section. A jet nozzle is provided inside the first cooling shell. The jet nozzle is provided with a jet orifice for spraying water towards the intermediate section. One end of the jet nozzle extends to the outside of the first cooling shell and is connected to an intelligent pump. The first cooling shell is provided with a first drain port. A second cooling shell is provided around the heat dissipation section. One end of the second cooling shell is provided with a water inlet, and the other end is provided with a second drain port. Intelligent valves are provided at both the water inlet and the second drain port. A water pump is connected to the water inlet. A third temperature sensor is provided at the outlet of the heat dissipation section, and a fourth temperature sensor is provided at the second drain port. The intelligent pump and the water pump are connected to the external water source through water pipes. The controller is electrically connected to the intelligent pump, the intelligent valve, the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor.

[0008] As a further improvement, the inlet section is a variable-thickness circular pipe with a thicker inlet and a thinner outlet.

[0009] Further, the inlet section is a variable-diameter circular pipe with a smaller diameter at the inlet and a larger diameter at the outlet.

[0010] Further, the jet nozzle is arranged parallel to the intermediate section. The number of jet orifices is multiple, and they are evenly spaced along the flow direction of the intermediate section.

[0011] Further, the number of jet nozzles is multiple, and the multiple jet nozzles are evenly arranged around the intermediate section.

[0012] Further, the outer wall of the intermediate section is provided with first flow disturbance ribs.

[0013] Further, the outer wall of the heat dissipation section is provided with second flow disturbance ribs.

[0014] Further, the controller is an ECU or a single-chip microcomputer or a PLC controller.

[0015] To achieve the second above-mentioned object, the present invention provides a control method for a cooling system of a boat engine, which includes the following steps:

[0016] Step 1. After starting the engine, the engine temperature control system first self-checks whether each component can work normally. If the inspection result shows that each component is normal, it enters the normal navigation mode; otherwise, it reports an error.

[0017] Step 2. Obtain the external water source temperature through the first temperature sensor, obtain the coolant temperature at the inlet through the second temperature sensor, obtain the coolant temperature at the outlet through the third temperature sensor, obtain the water temperature at the second drain through the fourth temperature sensor, and obtain the relative traveling speed of the boat; control the working flow rate of the intelligent pump according to the external water source temperature, the coolant temperature at the inlet, the coolant temperature at the outlet, and the relative traveling speed, and control the opening degrees of the intelligent valves at the water inlet and the second drain to control the water flow rate in the second cooling shell, so that the coolant reaches the most suitable temperature, and finally make the engine operate under the most suitable working conditions.

[0018] As a further improvement, control the working flow rate of the intelligent pump as follows:

[0019]

[0020]

[0021]

[0022] In the formula, h m / h is the fluid convective heat transfer coefficient, D is the characteristic length, λ is the fluid thermal conductivity, Re D is the Reynolds number, Pr is the Prandtl number, (Nu D ) m is the Nusselt number, u e is the relative traveling speed, v is the kinematic viscosity, T w / T j is the fluid inlet / outlet temperature, φ / q is the heat flux / heat flux density;

[0023] Control the water flow rate in the second cooling shell as follows:

[0024] φ = kAΔt m

[0025] φ = q m1 c 1 (t 1 '-t 1 ”) = q m2 c 2 (t 2 ”-t 2 ')

[0026] In the formula: φ is the heat flux, Δ: is the convective mean temperature difference, c 1 , c 2 are the specific heat capacities of the coolant and water respectively, q m1 , q m2 are the mass flow rates of the coolant and water respectively, k is the heat transfer coefficient between the heat dissipation section and the coolant, A is the heat transfer area between the heat dissipation section and the coolant, t 1 ', t1 ” are the coolant temperature at the inlet and the coolant temperature at the outlet respectively, specifically, t 2 ' and t 2 ” are the external water source temperature and the water temperature at the second drain outlet respectively.

[0027] Advantageous Effects

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] First, the present invention sprays water into the middle section in the first cooling shell by controlling the working flow rate of the intelligent pump for primary heat dissipation, reducing the high-temperature engine coolant to a lower temperature. Then, it controls the opening degrees of the intelligent valves at the water inlet and the second drain outlet to control the flow rate of the water flowing in the second cooling shell for secondary heat dissipation, making the coolant reach the most suitable temperature. Finally, the engine operates under the most suitable working conditions. By controlling the temperature of the boat engine through two-stage heat dissipation, compared with the prior art, the control is more precise and the temperature fluctuation of the engine coolant is smaller. Description of the Drawings

[0030] Figure 1 is a schematic structural diagram of the present invention;

[0031] Figure 2 is a schematic structural diagram of the middle section of the present invention;

[0032] Figure 3 is a control flow chart of the present invention.

[0033] Wherein: 1 - inlet section, 2 - middle section, 3 - heat dissipation section, 4 - first cooling shell, 5 - jet nozzle, 6 - jet orifice, 7 - intelligent pump, 8 - first drain outlet, 9 - second cooling shell, 10 - water inlet, 11 - second drain outlet, 12 - first flow disturbance rib. Specific Embodiments

[0034] The following further describes the present invention with reference to specific embodiments in the drawings.

[0035] Refer to Figures 1 to 3, a boat engine cooling system, comprising a controller, a cooling pipe connected to the engine coolant return circuit, and a first temperature sensor for detecting the temperature of the external water source. The cooling pipe includes an inlet section 1, an intermediate section 2, and a heat dissipation section 3 connected in sequence; the inlet section 1 is provided with a second temperature sensor, the periphery of the intermediate section 2 is provided with a first cooling shell 4, a jet nozzle 5 is arranged inside the first cooling shell 4, the jet nozzle 5 is provided with a jet orifice 6 for spraying water into the intermediate section 2, one end of the jet nozzle 5 extends to the outside of the first cooling shell 4 and is connected with an intelligent pump 7, the intelligent pump 7 is a pump that can adjust the flow rate according to parameters, the first cooling shell 4 is provided with a first drain port 8; the periphery of the heat dissipation section 3 is provided with a second cooling shell 9, one end of the second cooling shell 9 is provided with a water inlet 10, the other end is provided with a second drain port 11, both the water inlet 10 and the second drain port 11 are provided with intelligent valves, the intelligent valves are valves that can adjust the flow rate according to parameters, the water inlet 10 is connected with a water pump, the outlet of the heat dissipation section 3 is provided with a third temperature sensor, and the second drain port 11 is provided with a fourth temperature sensor; the intelligent pump 7 and the water pump are connected to the external water source through water pipes, and the controller is electrically connected to the intelligent pump 7, the intelligent valve, the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor.

[0036] The inlet section 1 is a variable-thickness circular pipe with a thicker thickness at the inlet and a thinner thickness at the outlet. The higher the temperature of the high-temperature fluid, the greater the thickness of the corresponding inlet section 1 at the inlet part with the highest temperature, and the structural strength is good, safe and reliable.

[0037] The inlet section 1 is a variable-diameter circular pipe with a smaller diameter at the inlet and a larger diameter at the outlet, which can decelerate and compress the coolant.

[0038] The jet nozzle 5 is arranged in parallel with the intermediate section 2, the number of jet orifices 6 is multiple, and they are evenly spaced along the flow direction of the intermediate section 2. The number of jet nozzles 5 is multiple, and the multiple jet nozzles 5 are arranged in parallel, that is, the multiple jet nozzles 5 share one intelligent pump 7 and are evenly arranged around the intermediate section 2. The outer wall of the intermediate section 2 is provided with a first flow disturbance rib 12, which can be used to strengthen the heat transfer of the coolant in the intermediate section 2.

[0039] The outer wall of the heat dissipation section 3 is provided with a second flow disturbance rib, which can be used to strengthen the heat transfer of the coolant in the heat dissipation section 3.

[0040] The controller is an ECU or a single-chip microcomputer or a PLC controller.

[0041] A control method for a boat engine cooling system includes the following steps:

[0042] Step 1. After starting the engine, the engine temperature control system first self-checks whether each component can work normally; if the inspection result shows that each component is normal, it enters the normal navigation mode; otherwise, an error is reported. It should be noted that the self-check of the engine system is an original function of the boat equipped with an engine control system at present, and the present invention does not improve its implementation method;

[0043] Step 2. Obtain the external water source temperature through the first temperature sensor, obtain the coolant temperature at the inlet through the second temperature sensor, obtain the coolant temperature at the outlet through the third temperature sensor, obtain the water temperature at the second drain port 11 through the fourth temperature sensor, and obtain the relative driving speed of the boat. The relative driving speed is the relative speed of the boat's driving and the water flow; control the working flow rate of the intelligent pump 7 according to the external water source temperature, the coolant temperature at the inlet, the coolant temperature at the outlet, and the relative driving speed, and control the opening degree of the intelligent valves at the water inlet 10 and the second drain port 11 to control the water flow in the second cooling shell 9, so that the coolant reaches the most suitable temperature, and finally make the engine operate under the most suitable working conditions. That is, when the water temperature in the driving water area is low or the engine is just started, the jet intensity of the jet nozzle 5 will weaken, and the opening degree of the intelligent valve will become smaller or closed. When the water temperature in the driving water area is high or the engine temperature is too high, the jet intensity of the jet nozzle 5 will increase, and the opening degree of the intelligent valve will increase.

[0044] Control the working flow rate of the intelligent pump 7 as follows:

[0045]

[0046]

[0047]

[0048] In the formula, h m / h is the convective heat transfer coefficient of the fluid, D is the characteristic length, λ is the thermal conductivity of the fluid, Re D is the Reynolds number, Pr is the Prandtl number, (Nu D ) m is the Nusselt number, u e is the relative driving speed, v is the kinematic viscosity, T w / T j is the fluid inlet / outlet temperature, φ / q is the heat flow rate / heat flux density;

[0049] Control the water flow in the second cooling shell 9 as follows:

[0050] φ = kAΔt m

[0051] φ = q m1 c 1 (t 1'-t 1 ) = q m2 c 2 (t 2 ”-t 2 )

[0052] Where: φ is the heat flux, Δ: is the average convective temperature difference, c 1 , c 2 are the specific heat capacities of the coolant and water respectively, q m1 , q m2 are the mass flow rates of the coolant and water respectively, k is the heat transfer coefficient between the heat dissipation section 3 and the coolant, A is the heat exchange area between the heat dissipation section 3 and the coolant, t 1 ', t 1 ” are the inlet coolant temperature and the outlet coolant temperature respectively, t 2 ', t 2 ” are the external water source temperature and the water temperature at the second drain 11 respectively. Finally, the opening degrees of the intelligent valves at the water inlet 10 and the second drain 11 are controlled according to the water flow rate in the second cooling shell 9.

[0053] Since the changes in the driving environment are not fixed. If the parameters collected by the system fluctuate back and forth. The jet intensity of the jet nozzle 5 and the opening degree of the intelligent valve will change continuously, which not only increases the burden on the system but also brings a very bad experience to passengers. To solve this problem, further improvements have been made in this embodiment.

[0054] The specific improvement is to preset the maximum fluctuation temperature; when the engine coolant temperature changes, then judge the relationship between the fluctuation temperature and the maximum fluctuation temperature. If the fluctuation temperature is greater than the maximum fluctuation temperature, then adjust the jet intensity of the jet nozzle 5 and the opening degree of the intelligent valve.

[0055] Compared with the prior art, the technical solution of the present invention uses water as the cooling medium, which greatly increases the heat exchange efficiency, and water, as a good and natural heat exchange medium, is easy to obtain on boats.

[0056] The cooling system is used to adjust the jet intensity of the jet nozzle 5 and the opening degree of the intelligent valve of the second cooling shell 9, so as to better control the coolant temperature and the engine temperature and adapt to different water environments.

[0057] The above is only the preferred embodiment of the present invention. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, and these will not affect the implementation effect of the present invention and the practicability of the patent.

Claims

1. A boat engine cooling system, characterized in that, it includes a controller, a cooling pipe connected to the engine coolant return circuit, and a first temperature sensor for detecting the temperature of the external water source. The cooling pipe includes an inlet section (1), an intermediate section (2), and a heat dissipation section (3) connected in sequence. A second temperature sensor is provided at the inlet section (1). A first cooling shell (4) is provided around the intermediate section (2). A jet nozzle (5) is provided inside the first cooling shell (4). The jet nozzle (5) is provided with a jet orifice (6) for spraying water towards the intermediate section (2). One end of the jet nozzle (5) extends to the outside of the first cooling shell (4) and is connected to an intelligent pump (7). The first cooling shell (4) is provided with a first drain port (8). A second cooling shell (9) is provided around the heat dissipation section (3). One end of the second cooling shell (9) is provided with a water inlet (10), and the other end is provided with a second drain port (11). Intelligent valves are provided at both the water inlet (10) and the second drain port (11). The water inlet (10) is connected to a water pump. A third temperature sensor is provided at the outlet of the heat dissipation section (3). A fourth temperature sensor is provided at the second drain port (11). The intelligent pump (7) and the water pump are connected to the external water source through water pipes. The controller is electrically connected to the intelligent pump (7), the intelligent valves, the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor.

2. The boat engine cooling system according to claim 1, characterized in that, the inlet section (1) is a variable-thickness circular pipe with a thicker inlet and a thinner outlet.

3. The boat engine cooling system according to claim 1, characterized in that, the inlet section (1) is a variable-diameter circular pipe with a smaller diameter at the inlet and a larger diameter at the outlet.

4. The boat engine cooling system according to claim 1, characterized in that, the jet nozzle (5) is arranged parallel to the intermediate section (2), and the number of jet orifices (6) is multiple, and they are evenly spaced along the flow direction of the intermediate section (2).

5. The boat engine cooling system according to claim 1, characterized in that, the number of jet nozzles (5) is multiple, and the multiple jet nozzles (5) are evenly arranged around the intermediate section (2).

6. The boat engine cooling system according to claim 1, characterized in that, the outer wall of the intermediate section (2) is provided with a first flow disturbance rib (12).

7. The boat engine cooling system according to claim 1, characterized in that, the outer wall of the heat dissipation section (3) is provided with a second flow disturbance rib.

8. The boat engine cooling system according to claim 1, characterized in that, the controller is an ECU or a single-chip microcomputer or a PLC controller.

9. A control method for a boat engine cooling system, characterized in that, it includes the following steps: Step 1. After starting the engine, the engine temperature control system first self-checks whether each component can work normally; If the inspection result shows that each component is normal, it enters the normal navigation mode; otherwise, an error is reported. Step 2. Obtain the external water source temperature through the first temperature sensor, obtain the coolant temperature at the inlet through the second temperature sensor, obtain the coolant temperature at the outlet through the third temperature sensor, obtain the water temperature at the second drain port (11) through the fourth temperature sensor, and obtain the relative traveling speed of the boat; control the working flow rate of the intelligent pump (7) according to the external water source temperature, the coolant temperature at the inlet, the coolant temperature at the outlet, and the relative traveling speed, and control the opening degrees of the intelligent valves at the water inlet (10) and the second drain port (11) to control the water flow rate in the second cooling shell (9), so that the coolant reaches the most suitable temperature, and finally enable the engine to operate under the most suitable working conditions.

10. The control method of a boat engine cooling system according to claim 9, wherein, control the working flow rate of the intelligent pump (7) as follows: where h m / h is the fluid convective heat transfer coefficient, D is the characteristic length, λ is the fluid thermal conductivity, Re D is the Reynolds number, Pr is the Prandtl number, (Nu D ) m is the Nusselt number, u e is the relative traveling speed, v is the kinematic viscosity, T w / T j is the fluid inlet / outlet temperature, φ / q is the heat flux / heat flux density; control the water flow rate in the second cooling shell (9) as follows: φ = kAΔt m φ = q m1 c 1 (t 1 '- t 1 ) = q m2 c 2 (t 2 ”- t 2 ) Where: φ is the heat flux, Δ is the average convective temperature difference, c 1 and c 2 are the specific heat capacities of the coolant and water respectively, q m1 and q m2 are the mass flow rates of the coolant and water respectively, k is the heat transfer coefficient between the heat dissipation section (3) and the coolant, A is the heat exchange area between the heat dissipation section (3) and the coolant, t 1 ', t 1 ” are the inlet coolant temperature and the outlet coolant temperature respectively, t 2 ', t 2 ” are the external water source temperature and the water temperature at the second drain outlet (11) respectively.

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