Method and system for quickly starting battery of methanol hybrid excavator at low temperature

Abstract

The invention discloses a low-temperature quick starting method and system for a battery of a methanol hybrid excavator. The method comprises the steps that low-voltage electricity is supplied to a whole vehicle, the temperature of cooling liquid in a methanol engine cylinder body and the temperature of methanol are obtained, and whether low-temperature collaborative heating is started or not is judged; if the low-temperature synergistic heating is started, heating the cooling liquid in the engine cylinder body by combusting methanol and heating the cooling liquid by methanol through a plate heat exchanger, and respectively heating the methanol engine cylinder body and a battery system by shunting the heated cooling liquid through an electromagnetic three-way water valve; the temperature of cooling liquid in a methanol engine cylinder body and the temperature of a battery system are obtained in real time, whether heating is stopped or not is judged, after the methanol engine cylinder body and the battery system both stop heating, the methanol engine is started, meanwhile, high-voltage electricity is applied to the whole vehicle, and the whole vehicle enters the working state. The problem that the whole methanol hybrid excavator is relatively long in heating time in a cold environment is solved.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery equipment control technology, and in particular to a method and system for rapid low-temperature start-up of a methanol hybrid excavator battery. Background Technology

[0002] With the rapid development and cost reduction of lithium battery technology, methanol hybrid excavators have been rapidly promoted in the market due to the low cost advantages of methanol and lithium batteries. Because their operating costs are significantly lower than those of traditional fuel excavators, they have been widely used in mining operations in Xinjiang, Tibet and other regions.

[0003] However, such operating areas often face extremely cold climate conditions, posing a severe challenge to the start-up and stable operation of methanol hybrid excavators: methanol itself has hydrophilic properties, and the water in it is easy to freeze in low-temperature environments. In addition, the difficulty of igniting methanol itself increases as the temperature decreases, and heating is required to ensure that the engine can start normally. At the same time, the energy output efficiency of lithium batteries decreases significantly in cold environments, and their service life is severely affected. They also need to be heated to a suitable temperature to achieve optimal performance.

[0004] In the existing technology, the low-temperature start-up heating scheme of methanol hybrid excavators adopts a step-by-step heating mode: first, the whole vehicle is powered by low voltage electricity, and the methanol heater is started using the low voltage power supply, which only heats the methanol engine separately; after the methanol engine is heated and started, high voltage electricity is then supplied to the battery system, and the battery is heated by starting the battery thermal management system (TMS).

[0005] Therefore, the existing technical solutions have obvious technical shortcomings: on the one hand, the engine heating and battery heating are carried out in separate steps, resulting in an excessively long total heating time for the vehicle to start at low temperatures, which seriously reduces the operating efficiency and cannot meet the needs of mining operations for rapid equipment response; on the other hand, if the vehicle is heated to low voltage while the battery is heated to high voltage in order to shorten the heating time, the high voltage will be directly output to the outside, which can easily cause safety hazards during daily operations or equipment maintenance, threatening the personal safety of operators and the operational safety of equipment. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method and system for rapid low-temperature start-up of methanol hybrid excavator batteries, which solves the problem of long heating time for methanol hybrid excavators in cold environments.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for rapid low-temperature start-up of a methanol hybrid excavator battery, comprising: installing a low-voltage power supply on the vehicle, acquiring the coolant temperature and methanol temperature inside the methanol engine cylinder, and determining whether to activate low-temperature co-heating; If low-temperature co-heating is activated, the coolant inside the engine cylinder is heated by burning methanol, and the cooled coolant after being heated by methanol through a plate heat exchanger and diverted through an electromagnetic three-way water valve is used to heat the methanol engine cylinder and the battery system respectively. The system monitors the coolant temperature inside the methanol engine cylinder and the battery system temperature in real time to determine whether to stop heating. Once the methanol engine cylinder and battery system have stopped heating, the methanol engine is started, and the entire vehicle is connected to high voltage, thus entering the working state.

[0008] As a further technical solution, if it is determined that low-temperature co-heating will not be activated, the methanol engine will be started directly, and the entire vehicle will be connected to high-voltage electricity, thus putting the vehicle into operation.

[0009] As a further technical solution, the specific method for determining whether to activate low-temperature co-heating is as follows: when the temperature of the coolant in the methanol engine cylinder is lower than the first temperature threshold, or the methanol temperature is lower than the second temperature threshold, low-temperature co-heating is activated.

[0010] As a further technical solution, methanol combustion is achieved by igniting the methanol in the methanol tank using an electrode ignition method. The released heat is then exchanged with the coolant to raise its temperature.

[0011] As a further technical solution, the battery system is heated by means of coolant circulation heating, wherein the heated coolant is circulated into the battery system by a water pump to heat the battery system.

[0012] As a further technical solution, the specific method of the electromagnetic three-way water valve diverting the heated coolant is as follows: the electromagnetic three-way water valve is opened, so that the heated coolant enters the methanol engine heating branch and the battery system heating branch respectively, and the methanol engine cylinder block and the battery system are heated at the same time, and the battery system is not powered by high voltage at this time.

[0013] Secondly, the present invention provides a low-temperature rapid start system for a methanol hybrid excavator battery, which is based on a low-temperature rapid start method for a methanol hybrid excavator battery provided in the first aspect, comprising: Methanol engine, hybrid motor system, battery system, hydraulic system, methanol-water heating system, battery thermal management system, and vehicle controller; The methanol-water heating system includes a methanol heating device, a heat exchanger, a water pump, and an electromagnetic three-way water valve. The electromagnetic three-way water valve is connected to the methanol engine and the battery system via pipelines. The vehicle controller is connected to the electromagnetic three-way water valve, the methanol engine, and the battery system via communication control lines. The battery thermal management system is connected to the battery system.

[0014] As a further technical solution, the methanol engine is connected to the hydraulic system via a coupling and is also driven by the hybrid motor system. Under heavy load, the methanol engine and the hybrid motor system work together to drive the hydraulic system.

[0015] As a further technical solution, under light load, the methanol engine drives the hybrid motor system to charge the battery system, and the battery system absorbs the energy output by the hybrid motor system.

[0016] As a further technical solution, the battery thermal management system includes a PTC, a water pump, and a controller. The PTC is electrically connected to the battery system. By supplying power to the PTC, the PTC generates heat to heat the coolant. The heated coolant is then circulated into the battery system by the water pump to heat the battery system in a coordinated manner.

[0017] One or more technical solutions of the present invention have the following beneficial effects: (1) This invention replaces the electromagnetic water valve in the methanol-water heating system with an electromagnetic three-way water valve, constructing a collaborative heating architecture of "methanol-engine cylinder block-battery system". Combined with the method of "synchronous start-up and collaborative heating of the whole vehicle after low voltage electricity", it breaks the step-by-step mode of "heating the engine first and then heating the battery" in the prior art. During the heating process, the heat generated by the combustion of methanol heats the engine cylinder block through the coolant and raises the temperature of the methanol itself through the plate heat exchanger. At the same time, the coolant is diverted through the electromagnetic three-way water valve to heat the battery system, realizing the synchronous heating of the three core objects. This significantly reduces the total heating time of the whole vehicle at low temperature and effectively improves the operating response speed and working efficiency of the equipment in the extremely cold mining environment.

[0018] (2) In the low-temperature co-heating stage, the battery system does not require high voltage. It can achieve temperature rise simply by circulating the coolant in the methanol-water heating system, avoiding the high voltage output risk caused by prematurely applying high voltage in the prior art to shorten the time. At the same time, the vehicle controller in the system precisely controls the switching of the electromagnetic three-way water valve through the communication control line. The connection design between the battery thermal management system and the battery system further ensures the stability of the heating process. From both the control logic and system structure aspects, it eliminates safety accidents caused by high voltage exposure during daily operation or equipment maintenance, and improves the overall safety of the machine operation. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the vehicle architecture of the present invention. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] Example 1 This embodiment provides a low-temperature rapid start system for a methanol hybrid excavator battery, such as... Figure 1 As shown, it includes a methanol engine, a hybrid motor system, a battery system, a hydraulic system, a methanol-water heating system, a battery thermal management system, and a vehicle control unit (VCU).

[0023] During operation, the methanol engine is connected to the hydraulic system via a coupling, directly driving the hydraulic system. Under heavy load, the methanol engine and the hybrid motor system work together to drive the hydraulic system, with the hybrid motor system supplementing the output power of the methanol engine, while the battery system supplies power to the hybrid motor system. Under light load, the methanol engine drives the hybrid motor system to charge the battery system, and the battery system absorbs the energy output from the hybrid motor system.

[0024] The battery thermal management system (external heating) is connected to the battery system. The heating module in the battery thermal management system mainly includes a PTC, a water pump, and a controller. The PTC is made of ceramic and is electrically connected to the battery system. By supplying power to the PTC, the PTC heats up the coolant. The heated coolant is then circulated into the battery system by the water pump to heat the battery system in a coordinated manner.

[0025] In this embodiment, the methanol-water heating system includes a methanol heating device, a heat exchanger, a water pump, and an electromagnetic three-way water valve. The electromagnetic three-way water valve is connected to the methanol engine and the battery system via pipelines. The vehicle controller is connected to the electromagnetic three-way water valve, the methanol engine, and the battery system via a communication control line. To improve heating efficiency and safety, this embodiment removes the electromagnetic water valve from the methanol-water heating system and replaces it with an electromagnetic three-way water valve. This allows for full utilization of the heat from the methanol-water heating system to simultaneously heat the methanol engine and the battery, without requiring the battery to be connected to high voltage, thus ensuring electrical safety.

[0026] This embodiment adds two electromagnetic three-way water valves controlled by the VCU because: the battery system typically only has one cooling water path, and adding another path would be insufficient. Therefore, an additional electromagnetic three-way water valve is needed to heat the battery's heating water path using the battery thermal management system. During cold start, when the methanol-water heating system heats the battery, the VCU controls the simultaneous opening of electromagnetic three-way valve 1 (leading to the battery) and electromagnetic three-way water valve 2 (leading to the battery), while closing the valve of electromagnetic three-way water valve 2 leading to the battery thermal management system (to prevent hot water from flowing into the battery thermal management system). When the battery temperature reaches a suitable level or after high pressure is applied, the VCU controls three-way water valve 1 to close the valve leading to the battery, close the valve of electromagnetic three-way valve 2 (leading to the electromagnetic three-way valve), and open the valves leading to the battery thermal management system and the valve leading to the battery. Simultaneously, the battery temperature is controlled solely by the battery thermal management system. Advantages: Compared to the vehicle-wide heating solution with distributed heating, synchronous heating can be achieved with low modification costs. It only requires the addition of two three-way water valves and changes to the piping and wiring harness. The addition of the electromagnetic three-way water valve 2 prevents hot water from entering the battery thermal management system, thus avoiding waste of hot water and loss of thermal energy and improving heating efficiency.

[0027] When the vehicle is stationary outdoors and the overall vehicle temperature becomes too low, the vehicle is powered on at low voltage, activating the methanol-water heating system. The VCU opens the three-way valve, allowing hot water to flow into the engine and battery, and finally circulate back to the methanol-water heating system. Because the engine and battery materials differ significantly, their heating rates will also differ greatly. When the battery temperature reaches a suitable level, the battery sends a signal to the VCU, which closes the solenoid valve in the battery heating circuit and reopens the engine heating water circuit. If the engine heats up quickly while the battery heats up slowly, the opposite control is applied. In other words, when the vehicle is powered on at low voltage, the high-voltage battery power is not applied, allowing for separate heating of the battery and engine, or one heating circuit, depending on the environment and operating conditions.

[0028] Example 2 Due to methanol's hydrophilic properties (methanol readily absorbs water, and the water in methanol will freeze at low temperatures) and the engine's inherent low-temperature characteristics (low cylinder temperature, viscous engine oil at low temperatures, and cold air), methanol engines are difficult to start at low temperatures without an external heating device. This embodiment provides a method for rapid low-temperature starting of a methanol hybrid excavator battery, specifically including the following technical solutions: At normal temperatures, the methanol in the fuel tank provides methanol energy to the methanol engine through the methanol-water heating system, but the methanol-water heating system is not operational. In cold environments, when the temperature of the methanol fuel and engine reaches 0°C (the temperature may vary depending on the engine and methanol type, and can be set according to the actual situation), starting the methanol engine requires heating the engine and methanol fuel to a suitable temperature (generally, the engine temperature should be above 0°C and the methanol temperature above 25°C, but this can be set according to the actual situation).

[0029] First, the vehicle's low-voltage electrical system acquires the coolant temperature and methanol temperature within the methanol engine cylinder via instruments to determine whether to activate low-temperature co-heating. Specifically, the method for determining whether to activate low-temperature co-heating is as follows: when the coolant temperature within the methanol engine cylinder is below a first temperature threshold, or the methanol temperature is below a second temperature threshold, low-temperature co-heating is activated. In this embodiment, the first temperature threshold is set to 0°C, and the second temperature threshold is set to 25°C. The first and second temperature thresholds can be set according to actual conditions.

[0030] If low-temperature co-heating is activated, the coolant inside the engine cylinder is heated by burning methanol, and the cooled coolant, which is then heated by switching to methanol via a plate heat exchanger and then diverted through an electromagnetic three-way water valve, is used to heat the methanol engine cylinder and the battery system respectively.

[0031] The methanol combustion process uses an electrode ignition method to ignite the methanol in the methanol tank, and the released heat is exchanged with the coolant to raise the coolant temperature.

[0032] Considering that the battery system is also affected by temperature, the battery can only guarantee its lifespan at a suitable temperature (generally 25°C). Therefore, the battery monitors its own temperature. The battery system is heated by coolant circulation heating, which is an external heating method utilizing the battery thermal management system. Specifically, after the battery is brought under high voltage at a low temperature, it controls the battery thermal management system to heat the battery via a communication control line. The heating module in the battery thermal management system includes a PTC, a water pump, and a controller. The PTC is made of ceramic and is electrically connected to the battery system. By supplying power to the PTC, it heats the coolant, which is then circulated back into the battery system by the water pump to further heat the battery system. This collaborative heating method is used to heat the battery system.

[0033] The system monitors the coolant temperature inside the methanol engine cylinder and the battery system temperature in real time to determine whether to stop heating. Once the methanol engine cylinder and battery system have stopped heating, the methanol engine is started, and the entire vehicle is connected to high voltage, thus entering the working state.

[0034] The vehicle controller controls the switching of the electromagnetic three-way water valve: when the coolant temperature in the methanol engine cylinder reaches the corresponding target temperature first (set to 0℃ in this embodiment, but can be adjusted according to actual conditions), the vehicle controller shuts off the heating branch corresponding to the methanol engine cylinder and keeps the heating branch corresponding to the battery system open until the battery system temperature reaches the corresponding target temperature (set to 25℃ in this embodiment, but can be adjusted according to actual conditions); when the battery system temperature reaches the corresponding target temperature first, the vehicle controller shuts off the heating branch corresponding to the battery system and keeps the heating branch corresponding to the methanol engine cylinder open until the coolant temperature reaches the corresponding target temperature.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid low-temperature start-up of a methanol hybrid excavator battery, characterized in that, include: The vehicle uses low-voltage electricity to obtain the coolant temperature and methanol temperature in the methanol engine cylinder block, and determines whether to start low-temperature co-heating. If low-temperature co-heating is activated, the coolant inside the engine cylinder is heated by burning methanol, and the cooled coolant after being heated by methanol through a plate heat exchanger and diverted through an electromagnetic three-way water valve is used to heat the methanol engine cylinder and the battery system respectively. The system monitors the coolant temperature inside the methanol engine cylinder and the battery system temperature in real time to determine whether to stop heating. Once the methanol engine cylinder and battery system have stopped heating, the methanol engine is started, and the entire vehicle is connected to high voltage, thus entering the working state.

2. The method for rapid low-temperature start-up of a methanol hybrid excavator battery as described in claim 1, characterized in that, If it is determined that low-temperature co-heating will not be activated, the methanol engine will be started directly, and the entire vehicle will be connected to high-voltage electricity, thus entering the working state.

3. The method for rapid low-temperature start-up of a methanol hybrid excavator battery as described in claim 1, characterized in that, The specific method for determining whether to activate low-temperature co-heating is as follows: when the coolant temperature in the methanol engine cylinder is lower than the first temperature threshold, or the methanol temperature is lower than the second temperature threshold, low-temperature co-heating is activated.

4. The method for rapid low-temperature start-up of a methanol hybrid excavator battery as described in claim 1, characterized in that, The methanol in the methanol tank is ignited by electrode ignition, and the heat released is exchanged with the coolant to raise the coolant temperature.

5. The method for rapid low-temperature start-up of a methanol hybrid excavator battery as described in claim 1, characterized in that, The battery system is heated by means of coolant circulation heating, in which heated coolant is circulated into the battery system by a water pump to heat the battery system.

6. The method for rapid low-temperature start-up of a methanol hybrid excavator battery as described in claim 1, characterized in that, The specific method for diverting the heated coolant using the electromagnetic three-way water valve is as follows: the electromagnetic three-way water valve is opened, allowing the heated coolant to enter the methanol engine heating branch and the battery system heating branch respectively, simultaneously heating the methanol engine cylinder block and the battery system, while the battery system is not receiving high-voltage electricity at this time.

7. A low-temperature rapid start system for a methanol hybrid excavator battery, based on the low-temperature rapid start method for a methanol hybrid excavator battery according to any one of claims 1-6, characterized in that, include: Methanol engine, hybrid motor system, battery system, hydraulic system, methanol-water heating system, battery thermal management system, and vehicle controller; The methanol-water heating system includes a methanol heating device, a heat exchanger, a water pump, and an electromagnetic three-way water valve. The electromagnetic three-way water valve is connected to the methanol engine and the battery system via pipelines. The vehicle controller is connected to the electromagnetic three-way water valve, the methanol engine, and the battery system via a communication control line. The battery thermal management system is connected to the battery system.

8. A low-temperature rapid start system for a methanol hybrid excavator battery as described in claim 7, characterized in that, The methanol engine is connected to the hydraulic system via a coupling and is also driven by the hybrid motor system. Under heavy load, the methanol engine and the hybrid motor system work together to drive the hydraulic system.

9. A low-temperature rapid start system for a methanol hybrid excavator battery as described in claim 8, characterized in that, Under light load, the methanol engine drives the hybrid electric motor system to charge the battery system, and the battery system absorbs the energy output by the hybrid electric motor system.

10. A low-temperature rapid start system for a methanol hybrid excavator battery as described in claim 7, characterized in that, The battery thermal management system includes a PTC, a water pump, and a controller. The PTC is electrically connected to the battery system. By supplying power to the PTC, the PTC generates heat to heat the coolant. The heated coolant is then circulated into the battery system by the water pump to heat the battery system in a coordinated manner.

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