Electronic water pump cooling system control method

Abstract

The present invention discloses a control method for an electronic water pump cooling system, comprising: using an electronic water pump as a water pump of an engine cooling system; setting a temperature map duty cycle set; selecting a target temperature map duty cycle set according to different engine outlet water temperatures; using the engine speed under the actual working condition of the cooling system and the engine load for the electronic water pump as actual data pairs, searching for a target data pair consistent with the actual data pair from the target temperature map duty cycle set, and using the duty cycle corresponding to the target data pair as the target duty cycle, adjusting the speed and flow of the electronic water pump according to the target duty cycle, so that the engine outlet water temperature is within the target range. The present invention can realize the decoupling of the water pump speed, so that the cold engine starts and warms up quickly, and solves the problem of low heat dissipation efficiency of the water pump at low flow rate.

Description

Technical Field

[0001] The invention relates to the field of engine cooling systems, and in particular to a control method for an electronic water pump cooling system. Background Art

[0002] The traditional engine cooling system uses a mechanical water pump, whose speed is proportional to the engine speed. It cannot adjust the flow according to the actual thermal load of the engine, and has high fuel consumption. During the low-temperature and high-speed warm-up process, the water pump consumes more shaft power, the thermostat has a large leakage problem, the warm-up process is slow, and the engine combustion and emissions are poor. Under high temperature, low speed and high load conditions, the water pump has a low speed and small flow, the engine has an overheating problem, and the vehicle radiator is difficult to arrange.

[0003] Therefore, a control method for an electronic water pump cooling system is needed to solve the problems of high water pump consumption, slow warm-up process, small flow rate and poor heat dissipation. Summary of the invention

[0004] In view of this, the purpose of the present invention is to overcome the defects in the prior art and provide an electronic water pump cooling system control method that can achieve water pump speed decoupling, so that the cold machine can be started and warmed up quickly, solving the problem of low heat dissipation efficiency of the water pump due to low flow rate.

[0005] The electronic water pump cooling system control method of the present invention comprises:

[0006] Use the electronic water pump as the water pump for the engine cooling system;

[0007] Setting a temperature map duty cycle set; wherein the temperature map is a data pair of engine speed and engine load for an electronic water pump;

[0008] According to the different engine water outlet temperatures, select the target temperature map duty cycle set;

[0009] The engine speed under the actual working conditions of the cooling system and the engine load for the electronic water pump are taken as the actual data pair, and a target data pair consistent with the actual data pair is found from the target temperature map duty cycle set. The duty cycle corresponding to the target data pair is taken as the target duty cycle, and the speed and flow rate of the electronic water pump are adjusted according to the target duty cycle so that the engine water outlet temperature is within the target range.

[0010] Furthermore, the temperature map duty cycle set includes a low temperature map duty cycle set, a medium temperature map duty cycle set and a high temperature map duty cycle set.

[0011] Furthermore, according to the different engine outlet water temperatures, a target temperature map duty cycle set is selected, specifically including:

[0012] When the engine is started cold and the outlet water temperature is less than 92°C, the low temperature map duty cycle set is used as the target temperature map duty cycle set;

[0013] When the water temperature rises and the outlet water temperature = 92°C, the medium temperature map duty cycle set is used as the target temperature map duty cycle set;

[0014] When the water temperature continues to rise and the outlet water temperature = 105°C, the high temperature map duty cycle set is used as the target temperature map duty cycle set;

[0015] When the water temperature starts to decrease and the outlet water temperature = 103°C, the medium temperature map duty cycle set is used as the target temperature map duty cycle set;

[0016] When the water temperature continues to decrease and the outlet water temperature = 62°C, the low temperature map duty cycle set is used as the target temperature map duty cycle set.

[0017] Furthermore, the method further includes: adjusting the rotation speed of the electronic fan according to the engine outlet water temperature and based on the electronic fan duty cycle, so that the engine outlet water temperature is within a fuel-saving temperature range.

[0018] Further, the duty cycle of the electronic fan is set according to the following method:

[0019] When the engine outlet water temperature is ≤95℃, the electronic fan duty cycle is 0%;

[0020] When the engine outlet water temperature is greater than 95°C and less than 105°C, the duty cycle of the electronic fan increases as the outlet water temperature increases;

[0021] When the engine outlet water temperature is ≥105℃, the electronic fan duty cycle is 100%.

[0022] Furthermore, the duty cycle D of the electronic fan is determined according to the following formula when the engine outlet water temperature is greater than 95°C and less than 105°C:

[0023] D = ΔT·C;

[0024] Where ΔT is the difference between the outlet water temperature and 95°C, and C is a constant.

[0025] The beneficial effects of the present invention are as follows: an electronic water pump cooling system control method disclosed in the present invention realizes decoupling of the water pump speed and the engine speed by introducing an electronic water pump instead of a mechanical water pump, can timely adjust the water pump speed and flow rate according to the actual speed and torque of the engine, and control the engine's water outlet temperature at a speed with the lowest water pump shaft power consumption, so that a rapid warm-up function can be achieved when the cold engine is started, decoupling of the water pump speed is achieved under low-speed and high-load conditions, the water pump speed can be automatically adjusted according to a map, the coolant flow rate of the radiator is increased, and the problem of low heat dissipation efficiency of a mechanical water pump due to low flow rate is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0027] Figure 1 A schematic diagram of a control strategy based on an electronic water pump of the present invention;

[0028] Figure 2 It is a schematic diagram of the HD15MA cooling system arrangement of the present invention;

[0029] Figure 3 It is a two-dimensional data graph corresponding to the low temperature map duty cycle set of the present invention;

[0030] Figure 4 It is a two-dimensional data graph corresponding to the medium temperature map duty cycle set of the present invention;

[0031] Figure 5 It is a two-dimensional data graph corresponding to the high temperature map duty cycle set of the present invention;

[0032] Figure 6 A schematic diagram showing the relationship between the duty cycle of the electronic fan and the engine outlet water temperature of the present invention;

[0033] Figure 7 Schematic diagram of target temperature for controlling the speed of an electronic fan according to the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings, as shown in the drawings:

[0035] The electronic water pump cooling system control method of the present invention comprises:

[0036] The electronic water pump is used as the water pump of the engine cooling system; in this embodiment, Figure 2 Taking the HD15MA cooling system shown as an example, an electronic water pump is used as the water pump of the engine cooling system;

[0037] Setting a temperature map duty cycle set; wherein the temperature map is a data pair of engine speed and engine load for an electronic water pump;

[0038] According to the different engine water outlet temperatures, select the target temperature map duty cycle set;

[0039] The engine speed under the actual working conditions of the cooling system and the engine load for the electronic water pump are taken as the actual data pair, and a target data pair consistent with the actual data pair is found from the target temperature map duty cycle set. The duty cycle corresponding to the target data pair is taken as the target duty cycle, and the speed and flow rate of the electronic water pump are adjusted according to the target duty cycle so that the engine water outlet temperature is within the target range.

[0040] In this embodiment, the temperature map duty cycle set includes a low temperature map duty cycle set, a medium temperature map duty cycle set and a high temperature map duty cycle set. The temperature map duty cycle set is a set composed of several temperature map duty cycles; Figure 3 As shown in the two-dimensional data diagram of the low temperature map duty cycle set, x represents the engine speed (the data in the first row), and y represents the engine load for the electronic water pump (the data in the first column); each x and each y form a data pair, and the data corresponding to the data pair is the duty cycle of the data pair. For example, when x is 850.00 and y is 35.010, the corresponding duty cycle is 5.0049, which is a low temperature map duty cycle. Figure 3 The meaning is the same. Figure 4 as well as Figure 5 They are respectively the two-dimensional data graph corresponding to the medium temperature map duty cycle set and the two-dimensional data graph corresponding to the high temperature map duty cycle set.

[0041] In this embodiment, according to the different engine outlet water temperatures, a target temperature map duty cycle set is selected, specifically including:

[0042] When the engine is started cold and the outlet water temperature is less than 92°C, the low temperature map duty cycle set is used as the target temperature map duty cycle set;

[0043] When the water temperature rises and the outlet water temperature = 92°C, the medium temperature map duty cycle set is used as the target temperature map duty cycle set;

[0044] When the water temperature continues to rise and the outlet water temperature = 105°C, the high temperature map duty cycle set is used as the target temperature map duty cycle set;

[0045] When the water temperature starts to decrease and the outlet water temperature = 103°C, the medium temperature map duty cycle set is used as the target temperature map duty cycle set;

[0046] When the water temperature continues to decrease and the outlet water temperature = 62°C, the low temperature map duty cycle set is used as the target temperature map duty cycle set.

[0047] Through the above settings, the target duty cycle in the target temperature map duty cycle set can be called by the ECU to perform temperature control. In the engine cooling start state, by calling the target duty cycle in the low temperature map duty cycle set, the electronic water pump is maintained near the minimum duty cycle, and the water pump is driven to operate at a low speed and a small flow rate, so that the thermostat can identify the engine outlet water temperature for real-time feedback.

[0048] In this embodiment, the electronic water pump cooling system control method of the present invention further includes: adjusting the speed of the electronic fan based on the electronic fan duty cycle according to the engine outlet water temperature, so that the engine outlet water temperature is within the fuel-saving temperature range. Specifically, based on the temperature map duty cycle of the electronic water pump, the electronic fan duty cycle is used to control the speed of the electronic fan in real time according to the target temperature PID, so that the outlet water temperature is controlled within the fuel-saving temperature range. Figure 7 As shown in the figure, the target temperature is determined based on the comprehensive sweep of the fuel economy and power of the engine under the universal characteristics, and different universal characteristic working conditions correspond to different target temperatures. The purpose of the target temperature is to achieve a high temperature state at low load, reduce friction work, and save fuel consumption; and a low temperature state at high load to ensure the intake volume, improve power, and reduce the risk of knocking.

[0049] In this embodiment, Figure 6 As shown, set the electronic fan duty cycle according to the following method:

[0050] When the engine outlet water temperature is ≤95℃, the electronic fan duty cycle is 0%;

[0051] When the engine outlet water temperature is greater than 95°C and less than 105°C, the duty cycle of the electronic fan increases as the outlet water temperature increases;

[0052] When the engine outlet water temperature is ≥105℃, the electronic fan duty cycle is 100%.

[0053] The duty cycle D of the electronic fan is determined according to the following formula when the engine outlet water temperature is greater than 95°C and less than 105°C:

[0054] D = ΔT·C;

[0055] Where ΔT is the difference between the outlet water temperature and 95°C, and C is a constant.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A control method for an electronic water pump cooling system, characterized in that: include: Use the electronic water pump as the water pump for the engine cooling system; Setting a temperature map duty cycle set; wherein the temperature map is a data pair of the engine speed and the engine load for the electronic water pump; the temperature map duty cycle set includes a low temperature map duty cycle set, a medium temperature map duty cycle set and a high temperature map duty cycle set; According to the different engine water outlet temperatures, select the target temperature map duty cycle set, including: When the engine is started cold and the outlet water temperature is less than 92°C, the low temperature map duty cycle set is used as the target temperature map duty cycle set; When the water temperature rises and the outlet water temperature = 92°C, the medium temperature map duty cycle set is used as the target temperature map duty cycle set; When the water temperature continues to rise and the outlet water temperature = 105°C, the high temperature map duty cycle set is used as the target temperature map duty cycle set; When the water temperature starts to decrease and the outlet water temperature = 103°C, the medium temperature map duty cycle set is used as the target temperature map duty cycle set; When the water temperature continues to drop and the outlet water temperature = 62°C, the low temperature map duty cycle set is used as the target temperature map duty cycle set; The engine speed under the actual working conditions of the cooling system and the engine load for the electronic water pump are taken as the actual data pair, and a target data pair consistent with the actual data pair is found from the target temperature map duty cycle set. The duty cycle corresponding to the target data pair is taken as the target duty cycle, and the speed and flow rate of the electronic water pump are adjusted according to the target duty cycle so that the engine water outlet temperature is within the target range.

2. The electronic water pump cooling system control method according to claim 1, characterized in that: Also includes: According to the engine outlet water temperature, the speed of the electronic fan is adjusted based on the electronic fan duty cycle so that the engine outlet water temperature is within the fuel-saving temperature range.

3. The electronic water pump cooling system control method according to claim 2, characterized in that: Set the electronic fan duty cycle as follows: When the engine outlet water temperature is ≤95℃, the electronic fan duty cycle is 0%; When the engine outlet water temperature is greater than 95°C and less than 105°C, the duty cycle of the electronic fan increases as the outlet water temperature increases; When the engine outlet water temperature is ≥105℃, the electronic fan duty cycle is 100%.

4. The electronic water pump cooling system control method according to claim 3, characterized in that: The duty cycle D of the electronic fan is determined according to the following formula when the engine outlet water temperature is greater than 95°C and less than 105°C: D = ΔT·C; Where ΔT is the difference between the outlet water temperature and 95°C, and C is a constant.

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