Rail transit vehicle and diesel engine heat preservation method and system

Abstract

The application discloses a rail transit vehicle and a diesel engine heat preservation method and system, obtains an ambient temperature, and fits a relationship between a cooling water temperature drop rate and the ambient temperature; a cooling water temperature rise rate is obtained by using the cooling water temperature drop rate and a remaining running time of a line non-electric section; a cooling water temperature heating power is calculated by using the cooling water temperature rise rate; a deviation between an actual cooling water temperature change rate and a theoretical cooling water temperature change rate is calculated, and the deviation is taken as an input of a PI controller; a heating device voltage is calculated by using the cooling water temperature heating power and an output of the PI controller, and an output power of the heating device is adjusted according to the calculated voltage; an expansion water tank of the heating device is communicated with a circulating water pump, a diesel engine and an oil heat exchanger. The application can reduce the phenomenon of output voltage oscillation caused by a large load switching of a locomotive vehicle auxiliary power supply or train power supply when the circulating water pump and the heater are repeatedly started and stopped, and improves the reliability of diesel engine heat preservation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit, in particular to a rail transit vehicle and a diesel engine heat preservation method and system. BACKGROUND

[0002] The internal electric dual-source locomotive / motor train set adopts catenary current traction drive or internal combustion traction drive. In the catenary current traction mode, in order to save energy and protect the environment, the internal combustion diesel engine is not started, but a diesel engine heat preservation system needs to be configured to perform "hot preparation" for starting the diesel engine, keep the oil and water temperature of the diesel engine within a certain limit, and also avoid the temperature reduction causing the cooling water to freeze and causing damage to the diesel engine and water system.

[0003] Currently, the diesel engine heat preservation of the locomotive vehicle usually adopts a circulating water pump + heater to achieve heat preservation, and adopts a water temperature threshold to control the start and stop of the heater, for example:

[0004] ① "Diesel engine heat preservation and preheating device and method for internal combustion locomotive" (application number 202211413304.1) discloses a diesel engine heat preservation and preheating device and method for internal combustion locomotive. The heat preservation and preheating device includes: a heater, which is arranged in the expansion tank of the diesel engine cooling circulation system; a preheating circulating water pump, one end of which is connected with the expansion tank, and the other end is connected with the pipeline of the diesel engine cooling circulation system. The heat preservation and preheating device places the heater in the expansion tank of the cooling circulation system. The control method of this scheme sets a threshold value of the circulating water temperature of the cooling circulation system when the diesel engine is stopped. When the circulating water temperature is lower than the threshold value, the heater is started to heat the circulating water in the expansion tank. The circulating water is heated at the same time, and the preheating circulating water pump is used to send the circulating water into the diesel engine cooling circulation system to preheat the diesel engine. When the circulating water temperature reaches the threshold value, the heater is closed to stop heating the circulating water.

[0005] ② "Method and equipment for heat preservation of diesel engine cooling water and oil in low temperature environment" (application number 201610751476.8) introduces a method and equipment for heat preservation of diesel engine cooling water and oil in low temperature environment. Through the automatic start and stop mode, the automatic heat preservation of the diesel engine cooling water and oil in the low temperature environment is realized, the temperature of the diesel engine cooling water and oil is ensured to be within the allowable range of the locomotive, and the normal use of the locomotive is ensured. When it is detected that the temperature of the low temperature water inlet pipeline of the diesel engine cooling water is lower than the set value, the control computer starts the circulating water pump and heats it through the heater. When it is detected that the temperature is higher than the set value, the circulating water pump is stopped and the electric control valve is closed.

[0006] The above methods all use fixed resistance heaters to heat oil and water, and realize temperature control through starting and stopping of the circulating water pump and the heater. Since the temperature is different in different regions and seasons, the cooling water temperature drop rate of the diesel engine is also different, and the lower the temperature, the faster the drop rate. Therefore, if a fixed power heater is used to realize temperature control, the water pump and the heater will be started and stopped discontinuously according to the temperature, which will affect the load input of the auxiliary power supply of the locomotive vehicle or the train power supply, and excessive load switching will cause output voltage oscillation. Especially when other loads are large, if the water pump or the heater load is started and stopped discontinuously, the voltage output of the auxiliary power supply or the train power supply will be greatly affected, and the use of the water pump will also be negatively affected. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a rail transit vehicle and a diesel engine heat preservation method and system, which automatically adjusts the heating power of a heating device according to the ambient temperature, reduces the influence of sudden load input of the water pump and the like on the auxiliary power supply / train power supply system, and reduces the probability of output voltage oscillation.

[0008] To solve the above technical problems, the technical solution adopted by the present application is as follows: a diesel engine heat preservation method, comprising the following steps:

[0009] Obtaining the ambient temperature, and fitting the relationship between the cooling water temperature drop rate and the ambient temperature;

[0010] Obtaining the cooling water temperature rise rate using the cooling water temperature drop rate and the remaining running time of the line non-electric section;

[0011] Calculating the cooling water temperature heating power using the cooling water temperature rise rate;

[0012] Calculating the deviation between the actual cooling water temperature change rate and the theoretical cooling water temperature change rate, and taking the deviation as the input of a PI controller;

[0013] Calculating the heating device voltage using the cooling water temperature heating power and the output of the PI controller, and adjusting the output power of the heating device according to the calculated voltage; the expansion tank of the heating device is in communication with the circulating water pump, the diesel engine and the oil heat exchanger.

[0014] The present application adjusts the output power of the heating device according to the ambient temperature, realizes self-adaptive adjustment of the cooling water temperature, reduces the number of times of starting and stopping of the circulating water pump and the heater, reduces the probability of output voltage oscillation caused by excessive load switching of the auxiliary power supply of the locomotive vehicle or the train power supply, and improves the reliability of the diesel engine heat preservation.

[0015] In the application, the relationship expression of the cooling water temperature drop rate and the ambient temperature is as follows:

[0016] v 温降 =A×e B×T +B×T+C;

[0017] wherein e is a natural number, A, B and C are constants, T is the ambient temperature, and v 温降 is the cooling water temperature drop rate under the current ambient temperature.

[0018] In the application, the above relationship expression can be obtained by a fitting method.

[0019] The calculation formula of the cooling water temperature rise rate is as follows:

[0020]

[0021] wherein v 温升 is the diesel engine cooling water temperature rise rate under the current ambient temperature, T1 is the cooling water temperature when the line operation ends, i.e. the diesel engine cooling water temperature limit value, T2 is the cooling water temperature when the line operation starts, v 温降 is the cooling water temperature drop rate under the current ambient temperature, and t is the remaining running time of the line non-electric section, in hours.

[0022] The application combines the cooling water temperature drop rate, the remaining running time of the line non-electric section and the cooling water temperature to calculate the temperature rise rate, thereby improving the calculation accuracy and reliability of the cooling water temperature rise rate.

[0023] The calculation formula of the cooling water temperature heating power is as follows:

[0024] Q=c×L×ρ×v 温升 ×t;

[0025] wherein Q is the heating power, c is the specific heat capacity of the cooling water (such as ethylene glycol + deionized water), L is the cooling water volume, ρ is the cooling water density, v 温升 is the diesel engine cooling water temperature rise rate under the current ambient temperature, and t is the remaining running time of the line non-electric section, in hours.

[0026] The calculation formula of the heating device voltage U is as follows:

[0027]

[0028]

[0029] e(t)=v 理论冷却水变化 -v 实际冷却水变化 ;

[0030] wherein Q is the heating power, R is the resistance value of the heating device, and v实际冷却水变化 is an actual cooling water temperature change rate, v 理论冷却水变化 is a theoretical cooling water temperature change rate, U PI is an output value of the PI controller, K P is a proportional coefficient, K I is an integral coefficient, and the setting of the proportional coefficient and the integral coefficient can be set by using an engineering setting method.

[0031] The present application combines the PI controller to calculate the heating device voltage, improves the accuracy of the voltage calculation result, and the calculation process is simple.

[0032] As an inventive concept, the present application also provides a diesel engine heat preservation system, which comprises:

[0033] an ambient temperature sensor for acquiring an ambient temperature;

[0034] a cooling water temperature sensor for acquiring a temperature of cooling water;

[0035] a temperature adaptive power controller electrically connected with the ambient temperature sensor and the cooling water temperature sensor; for fitting to obtain a cooling water temperature drop rate and a relationship with the ambient temperature, for obtaining a cooling water temperature rise rate by using the cooling water temperature drop rate and a remaining operation time of a line non-electric section, and for calculating a cooling water temperature heating power by using the cooling water temperature rise rate;

[0036] a PI controller, an input of which is a deviation between the actual cooling water temperature change rate and the theoretical cooling water temperature change rate;

[0037] a PWM inverter controller for calculating a heating device voltage by using the cooling water temperature heating power and an output of the PI controller, and for adjusting an output voltage of the heating device according to the calculated voltage; wherein an expansion tank of the heating device is in communication with a circulating water pump, a diesel engine and an oil heat exchanger.

[0038] As an inventive concept, the present application also provides a diesel engine heat preservation system, which comprises:

[0039] one or more processors;

[0040] a memory having one or more programs stored thereon, which, when executed by the one or more processors, cause the one or more processors to implement the steps of the above-mentioned method of the present application.

[0041] As an inventive concept, the present application also provides a rail transit vehicle, which adopts the diesel engine heat preservation system as described above.

[0042] Compared with the prior art, the present application has the beneficial effect that the present application can reduce the phenomenon of output voltage oscillation caused by excessive load switching of the locomotive auxiliary power supply or train power supply when the circulating water pump and the heater are repeatedly started and stopped, and improves the reliability of the diesel engine heat preservation. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The heat preservation method flowchart of the embodiment of the present application;

[0044] Figure 2 The cooling water temperature reduction rate and the ambient temperature curve of the embodiment of the present application;

[0045] Figure 3 The heat preservation system structure block diagram of the embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the embodiment of the present application clearer, the technical scheme of the embodiment of the present application will be clearly and completely described below in combination with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0047] Embodiment 1

[0048] The embodiment 1 of the present application provides a diesel engine heat preservation method. When the train starts, the circulating water pump and the heating device of the diesel engine heat preservation system are put into operation. The heating power of the heating device is adaptively controlled according to the non-electric section running time, the ambient temperature and the cooling water temperature. The specific method comprises the following steps:

[0049] Obtaining the cooling water temperature reduction rate: the temperature adaptive power controller obtains the cooling water temperature reduction rate corresponding to the ambient temperature according to the ambient temperature sensor and the cooling water temperature reduction rate and ambient temperature relationship curve. The cooling water temperature reduction rate is mainly affected by different ambient temperatures, different heat insulation measures and the like. After the heat insulation measure is determined, the relationship curve between the cooling water temperature reduction rate and the ambient temperature T can be approximately obtained by using the fitting curve method based on the test data, for example:

[0050] v 温降 =A×e B×T +C

[0051] Wherein, e is a natural number, A, B, C can be calculated according to the specific test data analysis, such as a certain type of locomotive at ambient temperature-10 ℃ or so, the locomotive under static conditions, diesel engine oil temperature from 80 ℃ to 30 ℃, about 3 hours, oil temperature rate of about 17 ℃ / h, at ambient temperature-20 ℃ or so, the locomotive under static conditions, diesel engine oil temperature from 70 ℃ to 30 ℃, about 2 hours, oil temperature rate of about 20 ℃ / h, at ambient temperature 20 ℃ or so, the locomotive under static conditions, diesel engine water temperature from 60 ℃ to 48 ℃, about 2 hours, water temperature rate of about 5 ℃ / h, cooling water temperature reduction rate and ambient temperature curve is shown in Figure 2 .

[0052] By fitting the curve, the approximate relationship between the cooling water temperature reduction rate and the ambient temperature is obtained:

[0053] v 温降 =10.583×e -0.036×T

[0054] Obtain the remaining running time of the non-electric section: obtain the remaining running time of the non-electric section through the train operation monitoring system.

[0055] Calculate the cooling water temperature rise rate: the temperature adaptive power controller calculates the cooling water temperature rise rate according to the diesel engine cooling water temperature limit value, the actual cooling water temperature, and steps 1 and 2, and the calculation method is as follows:

[0056]

[0057] Wherein,

[0058] T1—cooling water temperature at the end of line operation, i.e. diesel engine cooling water temperature limit value, unit ℃;

[0059] T2—cooling water temperature at the beginning of line operation, unit ℃;

[0060] v 温降 —diesel engine cooling water temperature reduction rate at this ambient temperature, unit ℃ / h;

[0061] v 温升 —diesel engine cooling water temperature rise rate at this ambient temperature, unit ℃ / h;

[0062] t—remaining running time of non-electric section, unit h.

[0063] Calculate the cooling water temperature heating power: the temperature adaptive power controller combines the cooling water volume, density, and remaining running time of the non-electric section, and combines step 3 to calculate the cooling water temperature heating power, and the calculation method is as follows:

[0064] Q=c×L×p×v温升 ×t;

[0065] Where Q—heating power; C—specific heat capacity; L—cooling water volume; ρ—cooling water density; v 温升 —The rate of temperature rise of the diesel engine cooling water at this ambient temperature; t—The remaining operating time of the de-energized section of the line.

[0066] Calculate the voltage of the diesel engine insulation heating resistor: The temperature adaptive power controller uses the actual and theoretical coolant temperature change rates, combined with the output heating resistor voltage control requirements from step 4, through a PI controller. The control method is as follows:

[0067]

[0068]

[0069] e(t) = v 理论冷却水变化 -v 实际冷却水变化 ;

[0070] Where, U—heating device voltage; Q—heating power; R—heating device resistance; v 实际冷却水变化 —Actual rate of change of diesel engine cooling water; v 理论冷却水变化 —Theoretical rate of change of diesel engine cooling water, U PI K is the output value of the PI controller. P K is the proportionality coefficient. I The integral coefficient, proportional coefficient, and integral coefficient can be set using the engineering tuning method.

[0071] The embodiments of the present invention are applicable to locomotives, EMUs, or trains with dual internal power sources.

[0072] Example 2

[0073] Embodiment 2 of the present invention provides a heat preservation system corresponding to Embodiment 1 described above. For example... Figure 3 As shown, the insulation system includes a temperature-adaptive power controller, a PWM inverter controller, a heating device (including an expansion tank), an oil heat exchanger, a circulating water pump, an ambient temperature sensor, a cooling water temperature sensor, and water circulation piping. The temperature-adaptive power controller outputs voltage control signals based on the ambient temperature sensor, the cooling water temperature sensor, and the operating time provided by the train operation monitoring system. The PWM inverter controller adjusts the voltage of the heating device to control its heating power. The circulating water pump, the heating device (including the expansion tank), and the oil heat exchanger achieve thermal insulation of the diesel engine and engine oil through the cooling water circulation piping. After the PWM inverter adjusts the voltage of the heating device, continuous insulation of the diesel engine's unpowered areas can be achieved through the circulating water pump and the heating device (including the expansion tank).

[0074] Example 3

[0075] Embodiment 2 provides a heat preservation system corresponding to the above-mentioned embodiment 1, comprising a memory, a processor and a computer program stored in the memory; the processor executes the computer program stored in the memory to realize the steps of the method of the above-mentioned embodiment 1.

[0076] In some implementations, the memory can be a high-speed random access memory (RAM: Random Access Memory), and can also include a non-volatile memory, for example, at least one disk memory.

[0077] In other implementations, the processor can be integrated with the train control system, which is not limited here.

[0078] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all the preferred embodiments and all the changes and modifications falling within the scope of the present application.

[0079] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for heat preservation of a diesel engine, characterized in that, Includes the following steps: The ambient temperature is obtained, and the relationship between the cooling water temperature drop rate and the ambient temperature is fitted. The cooling water temperature rise rate is obtained by using the cooling water temperature drop rate and the remaining operating time of the power-off section of the line. The cooling water temperature rise rate is used to calculate the cooling water heating power; Calculate the deviation between the actual cooling water temperature change rate and the theoretical cooling water temperature change rate, and use the deviation as the input of the PI controller; The voltage of the heating device is calculated using the cooling water temperature, heating power, and the output of the PI controller. The output power of the heating device is then adjusted based on the calculated voltage. The expansion tank of the heating device is connected to the circulating water pump, the diesel engine, and the engine oil heat exchanger. The relationship between the cooling water temperature drop rate and the ambient temperature is expressed as follows: ； Where e is a natural number, A, B, and C are constants, and T is the ambient temperature. The rate of temperature drop of the cooling water at the current ambient temperature; The formula for calculating the cooling water temperature rise rate is: ； in, The rate of temperature rise of the diesel engine coolant at the current ambient temperature. This refers to the cooling water temperature at the end of the line's operation, i.e., the diesel engine cooling water temperature limit. The cooling water temperature at the start of line operation. The cooling water temperature drop rate is given by the current ambient temperature, and t is the remaining operating time of the de-energized section of the line, in hours.

2. The diesel engine heat preservation method according to claim 1, characterized in that, The formula for calculating the heating power of the cooling water temperature is: ； Where Q is the heating power, c is the specific heat capacity of the cooling water, L is the volume of the cooling water, and is the density of the cooling water.

3. The diesel engine heat preservation method according to claim 1, characterized in that, The formula for calculating the voltage U of the heating device is: ； ； ； Where Q is the heating power and R is the resistance of the heating device. This represents the actual rate of change of cooling water temperature. This represents the theoretical rate of change of cooling water temperature. The output value of the PI controller. This is the proportionality coefficient. is the integral coefficient.

4. A diesel engine insulation system, characterized in that, include: An ambient temperature sensor is used to acquire the ambient temperature. Cooling water temperature sensor, used to obtain the temperature of cooling water; A temperature-adaptive power controller is electrically connected to the ambient temperature sensor and the cooling water temperature sensor. The relationship between the cooling water temperature drop rate and the ambient temperature is fitted to obtain the cooling water temperature rise rate using the cooling water temperature drop rate and the remaining operating time of the power-off section of the line, and the cooling water temperature heating power is calculated using the cooling water temperature rise rate. The relationship between the cooling water temperature drop rate and the ambient temperature is expressed as follows: Where e is a natural number, A, B, and C are constants, and T is the ambient temperature. The cooling water temperature drop rate is the current ambient temperature; the cooling water temperature rise rate is calculated using the following formula: ;in, The rate of temperature rise of the diesel engine coolant at the current ambient temperature. This refers to the cooling water temperature at the end of the line's operation, i.e., the diesel engine cooling water temperature limit. The cooling water temperature is the temperature at which the line begins operation, and t is the remaining operating time of the de-energized section of the line, in hours. The input to the PI controller is the deviation between the actual rate of change of cooling water temperature and the theoretical rate of change of cooling water temperature. A PWM inverter controller is used to calculate the voltage of the heating device using the cooling water temperature heating power and the output of the PI controller, and to adjust the output voltage of the heating device according to the calculated voltage; wherein, the expansion tank of the heating device is connected to the circulating water pump, the diesel engine, and the oil heat exchanger.

5. A diesel engine insulation system, characterized in that, include: One or more processors; A memory having stored one or more programs thereon, which, when executed by one or more processors, cause the one or more processors to perform the steps of the method according to any one of claims 1 to 3.

6. A rail transit vehicle, characterized in that, It employs the diesel engine insulation system described in claim 4 or 5.

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