An LNG commercial vehicle generator cooling system and LNG commercial vehicle

Abstract

The utility model discloses a kind of LNG commercial vehicle generator cooling system and LNG commercial vehicle, belong to LNG commercial vehicle technical field, including generator, LNG engine, vortex tube, LNG engine is connected with vaporizer by third pipeline, vaporizer is connected with LNG gas tank by second pipeline;Vortex tube includes mutually communicating air inlet pipe and cold end pipe, hot end pipe;Cold end pipe connects first pipeline, the two gas outlets of first pipeline are opposite the two air inlets of generator, and the internal components of generator are cooled down;Hot end pipe connects fourth pipeline, fourth pipeline is connected with vaporizer, and liquefied gas in vaporizer is heated.In whole vehicle, vortex tube is increased, vortex tube transports cold air to the inside of generator, and the internal components of generator are cooled down, without improving the inside of generator;The hot air output by vortex tube is heated by vaporizer, LNG engine coolant is heated, and enough heat is provided for heating liquefied natural gas in vaporizer.

Description

Technical Field

[0001] This utility model belongs to the field of LNG commercial vehicle technology, specifically relating to an LNG commercial vehicle generator cooling system and an LNG commercial vehicle. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Currently, LNG (liquefied natural gas) commercial vehicles, especially heavy trucks equipped with parking air conditioners, experience excessive battery discharge during the summer due to the use of parking air conditioners. This causes the generator to operate under extreme load for extended periods, resulting in continuous high temperatures in the generator stator (reaching over 235°C). Ultimately, this leads to stator coil ablation (failure after 310 hours of full-load operation at 93°C in the laboratory), ultimately causing generator failure.

[0004] To prevent generator overheating, existing technologies have proposed the following strategies: firstly, reducing stator resistance and increasing slot fill factor; secondly, increasing winding height and heat dissipation area. While these solutions improve the generator's overload resistance to some extent, for heavy trucks operating under extreme loads for extended periods in high-temperature environments, the inability to reduce temperature can still lead to burn-out failures. Furthermore, all of these methods involve modifications to the generator's internal structure.

[0005] LNG commercial vehicles use LNG engines, which require heating to vaporize the fuel from a liquid to a gaseous state. Currently, LNG engines primarily utilize the engine's coolant for heating. However, the heat exchanger requires a large amount of heat, resulting in a slow coolant warm-up rate and a prolonged warm-up time. The critical temperature for LNG vapor-liquid conversion is -82.5℃. In the gas pipeline, if the gas temperature drops below -70℃, it will reduce the lifespan of the injection valves. Furthermore, the LNG engine's water pump not only powers the cooling system but also sometimes circulates coolant to the hydraulic retarder or transmission. For LNG engines with EGR (Exhaust Gas Refrigerant Regulator) and meeting China VI emission standards, coolant is also needed to dissipate heat from the EGR and exhaust gas venturi, leading to excessive power consumption by the water pump and increased overall vehicle fuel consumption. Utility Model Content

[0006] To address the aforementioned problems, this utility model provides an LNG commercial vehicle generator cooling system and an LNG commercial vehicle. It adds a vortex tube, a gas storage tank, and an air compressor to the vehicle. Compressed gas is input into the vortex tube, and the cold end of the vortex tube delivers cold air to the generator through a first pipe. The cold air output from the vortex tube continuously flows through the generator, cooling the internal components without requiring modifications to the generator itself, making modifications relatively convenient. The hot gas output from the vortex tube is then heated by the carburetor, supplementing the LNG engine coolant heating method and ensuring sufficient heat is provided to the liquefied natural gas in the carburetor, resulting in better heating performance. Furthermore, when the coolant temperature is low, heating is only provided by the hot gas from the hot end tube, reducing the power consumption of the water pump and lowering fuel consumption.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] Firstly, a cooling system for an LNG commercial vehicle generator is provided, comprising:

[0009] The generator has two air inlets;

[0010] The LNG engine's cylinders are connected to the vaporizer via a third pipeline, and the vaporizer is connected to the LNG tank via a second pipeline.

[0011] A vortex tube consists of an inlet pipe, a cold end pipe, and a hot end pipe that are connected to each other. Compressed gas is introduced into the inlet pipe. The compressed gas entering the vortex tube is separated into hot gas and cold gas. The hot gas is discharged from the hot end pipe and the cold gas is discharged from the cold end pipe.

[0012] The cold end pipe is connected to the first pipe, and the two air outlets of the first pipe are directly opposite the two air inlets of the generator to cool the internal components of the generator.

[0013] The hot end pipe is connected to the fourth pipe, which is connected to the vaporizer to heat the liquefied gas inside the vaporizer.

[0014] Preferably, the cooling system further includes an air compressor, which is connected to the intake pipe and inputs compressed gas into the vortex tube.

[0015] Preferably, the cooling system further includes an air storage tank, which is located between the air compressor and the air inlet pipe and is connected to the air outlet of the air compressor; the air storage tank and the air inlet pipe are connected by a fifth pipeline; a first control valve is installed on the fifth pipeline.

[0016] Preferably, a coolant circulation pipeline is provided between the carburetor and the LNG engine; a second control valve is provided on the coolant circulation pipeline.

[0017] Preferably, a liquefied natural gas (LNG) pipe is installed inside the vaporizer, with a coolant heat exchange pipe at the bottom and a hot gas heat exchange pipe at the top.

[0018] Preferably, the two ends of the liquefied natural gas pipe are connected to the second and third pipelines respectively; the inlet and outlet of the coolant heat exchange pipe are connected to the coolant circulation pipeline; one end of the hot gas heat exchange pipe is connected to the fourth pipeline, and the other end is connected to the exhaust pipeline.

[0019] Preferably, the cooling system further includes an electronic control device, which is connected to the generator via a signal line to acquire information about the generator's external load and internal temperature.

[0020] Preferably, temperature sensors are installed on the second pipeline, the coolant circulation pipeline, and the fourth pipeline, and the temperature sensors are all connected to the electronic control device.

[0021] Preferably, the first control valve and the second control valve are connected to the electronic control device.

[0022] Secondly, an LNG commercial vehicle is provided, which utilizes the aforementioned LNG commercial vehicle generator cooling system.

[0023] Compared with the prior art, the advantages and positive effects of this utility model are:

[0024] This invention adds a vortex tube, a gas storage tank, and an air compressor to the vehicle. Compressed gas is input into the vortex tube, and the cold end of the vortex tube delivers cold air to the generator through a first pipe. The cold air output from the vortex tube continuously flows through the generator, cooling the internal components without requiring modifications to the generator itself, making modifications relatively convenient. The hot gas output from the vortex tube is heated by the carburetor, assisting the LNG engine coolant heating method and ensuring sufficient heat is provided to heat the liquefied natural gas in the carburetor, resulting in better heating performance. Furthermore, when the coolant temperature is low, heating is provided only through the hot gas from the hot end tube, which also reduces the power consumption of the water pump and lowers fuel consumption. Attached Figure Description

[0025] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0026] Figure 1 This is a schematic diagram of the cooling system of Embodiment 1 or 2 of this utility model;

[0027] Figure 2 This is a schematic diagram of the generator according to Embodiment 1 or 2 of this utility model;

[0028] In the picture:

[0029] 1. Generator; 11. First pipeline; 2. Vortex tube; 20. Inlet pipe; 21. Cold end pipe; 22. Hot end pipe; 3. LNG engine; 4. Carburetor; 41. Second pipeline; 42. Third pipeline; 43. Fourth pipeline; 5. LNG tank; 6. Coolant circulation pipeline; 61. Second control valve; 7. Air compressor; 8. Air storage tank; 81. Fifth pipeline; 82. First control valve; 9. Electronic control device. Detailed Implementation

[0030] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] Definitions:

[0032] Vortex tube: An energy diversion device that uses an internally replaceable generator to control and achieve the required temperature and flow rate (the lowest temperature of the air generated at the cold end can reach -46℃, and the highest temperature of the air generated at the hot end can reach 127℃). Compressed air is used for intake, and it enters the vortex chamber tangentially through the nozzle flow channel. After swirling in the vortex chamber, the swirling gas undergoes energy separation as it flows towards the hot end, gradually splitting into two streams, one hot and one cold. The outer layer of gas flows along the wall from the inlet to the hot end outlet, and its temperature gradually increases before flowing out from the hot end outlet. The inner layer of gas flows along the axis from the hot end valve to the cold end outlet, and its temperature gradually decreases before finally flowing out from the cold end outlet.

[0033] LNG: Liquefied Natural Gas, whose main component is methane (CH4), is natural gas that has been purified, compressed, and cooled to its boiling point (-162℃) to become a liquid. It is colorless, odorless, non-toxic, insoluble in water, and non-corrosive to metals.

[0034] Vaporizer: Installed between the LNG engine and the LNG tank, it is a device that heats the liquid gas until it vaporizes.

[0035] The present invention will now be described in detail with reference to the accompanying drawings.

[0036] Example 1

[0037] This embodiment discloses a generator cooling system for LNG commercial vehicles, such as... Figure 1 , Figure 2As shown, the system includes a generator 1 with two air inlets. It also includes a vortex tube 2, which comprises an interconnected intake pipe 20, a cold end pipe 21, and a hot end pipe 22. The intake pipe 20 introduces compressed gas, causing it to separate into hot and cold gas within the vortex tube 2. The hot gas exits through the hot end pipe 22, and the cold gas exits through the cold end pipe 21. The cold end pipe 21 connects to the intake pipe of a first pipe 11, with its two outlets facing the two air inlets of the generator 1. Cold gas is blown out from the cold end pipe 21 and into the generator 1 via the first pipe 11, cooling the stator, rotor, and other internal components.

[0038] like Figure 1 As shown, an LNG commercial vehicle generator cooling system also includes an LNG engine 3. The cylinder of the LNG engine 3 is connected to a vaporizer 4 via a third pipeline 42. The vaporizer 4 is connected to an LNG tank 5 via a second pipeline 41. The LNG tank 5 contains low-temperature liquefied natural gas. The low-temperature liquefied natural gas enters the vaporizer 4 for heat exchange, heats up and vaporizes, and then enters the LNG engine 3 for combustion to do work.

[0039] like Figure 1 As shown, a coolant circulation pipeline 6 is also provided between the vaporizer 4 and the LNG engine 3. When the LNG engine 3 is working, it will release a lot of heat. The coolant enters the LNG engine 3 and carries the heat with it when it comes out. After the coolant carrying the heat enters the vaporizer 4, it exchanges heat with the low temperature liquefied natural gas in the vaporizer 4, so that the liquefied natural gas is heated and vaporized and enters the cylinder of the LNG engine 3 for combustion to do work. The LNG engine coolant after heat exchange returns to the LNG engine 3 to cool the LNG engine 3 and take away some of the heat.

[0040] like Figure 1 As shown, the hot end pipe 22 is connected to the fourth pipe 43, which is also connected to the vaporizer 4, and can heat the liquefied natural gas in the vaporizer 4. The hot end pipe 22 and the coolant circulation pipe 6 simultaneously heat the liquefied natural gas in the vaporizer 4, ensuring that sufficient heat is provided to heat the liquefied natural gas in the vaporizer, so that the heating effect of the vaporizer is better; ensuring that the temperature of the liquefied natural gas is above -70℃, and avoiding reducing the service life of the injection valve.

[0041] Specifically, the vaporizer 4 is equipped with a liquefied natural gas pipe, a coolant heat exchange pipe at the bottom of the liquefied natural gas pipe and a hot gas heat exchange pipe at the top; the two ends of the liquefied natural gas pipe are connected to the second pipe 41 and the third pipe 42 respectively; the inlet and outlet of the coolant heat exchange pipe are connected to the coolant circulation pipe 6; one end of the hot gas heat exchange pipe is connected to the fourth pipe 43 and the other end is connected to the exhaust pipe.

[0042] like Figure 1As shown, in order to supply compressed gas, the generator cooling system also includes an air compressor 7, which is connected to the air inlet pipe 20 of the vortex tube 2 to input the gas compressed by the air compressor 7 into the vortex tube 2.

[0043] like Figure 1 As shown, the generator cooling system also includes: an air storage tank 8, which is located between the air compressor 7 and the inlet pipe 20 of the vortex tube 2, and is connected to the outlet of the air compressor 7; the air storage tank 8 and the inlet pipe 20 of the vortex tube 2 are connected by a fifth pipeline 81. The compressed gas produced by the air compressor 7 can be stored through the air storage tank 8.

[0044] It should be explained that the air tank 8, air compressor 7, and vortex tube 2 can all be installed on the vehicle without modifying the generator's internal structure. The modification is relatively convenient and the cost is relatively low. The compressed air enters the vortex tube 2 and is divided into hot air and cold air to heat the carburetor and cool the generator. This not only ensures the heating effect of the carburetor 4 together with the coolant heating, but also allows a continuous supply of low-temperature cold air to enter the generator and carry away the heat, thus achieving continuous cooling.

[0045] It should be noted that the gas temperature at the cold end of the vortex tube varies with the gas pressure entering the tube, showing a direct proportional relationship. Simulation estimates indicate that a typical vortex tube of approximately 10cm in length, with an input gas pressure of 6.9 bar, can achieve a cold end gas temperature of -15℃ or lower.

[0046] like Figure 1 As shown, a first control valve 82 is installed on the fifth pipeline 81. When the first control valve 82 is opened, the air tank 8 releases compressed air into the air inlet pipe 20 of the vortex tube 2, thereby generating cold air and hot air in the vortex tube 2. The cold air flows out from the cold end pipe 21 to cool down the generator 1.

[0047] like Figure 1 As shown, a second control valve 61 is provided on the coolant circulation pipe 6 to control the opening and closing of the coolant circulation pipe 6.

[0048] like Figure 1 As shown, the generator cooling system also includes an electronic control unit 9 (ECU). The ECU is connected to the generator 1 via a signal line and is used to acquire the external load and internal temperature information of the generator 1. Based on the external load and internal temperature information of the generator 1, the ECU controls the opening or closing of the first control valve 82.

[0049] Specifically, after the vehicle is powered on, the ECU monitors the external load and internal temperature of the generator 1. For example, when the generator 1 has a large load and the overload operation time exceeds t0, or when the internal temperature of the generator 1 is higher than T0, the ECU sends a signal to the first control valve 82, causing high-pressure gas at pressure P1 to enter the vortex tube 2, which then introduces low-temperature gas into the generator 1 to cool the stator, rotor, and other components. When the external load of the generator is small or the internal temperature of the generator is less than T0, the ECU closes the first control valve.

[0050] Furthermore, temperature sensors are installed on the second pipeline, the coolant circulation pipeline, and the fourth pipeline. The temperature sensors are connected to the electronic control device 9 to monitor the LNG gas temperature, coolant temperature, and hot gas temperature output from the hot end of the vortex tube. The monitored LNG gas temperature, coolant temperature, and hot gas temperature output from the hot end of the vortex tube are transmitted to the electronic control device 9. The electronic control device 9 is also electrically connected to the second control valve 61. Based on the acquired LNG gas temperature, coolant temperature, and hot gas temperature output from the hot end of the vortex tube, the electronic control device 9 controls the opening or closing of the second control valve 61.

[0051] It should be noted that the LNG engine 3 has a low temperature when it is first started, and the heat exchanger requires a lot of heat. Therefore, the coolant heats up slowly, requiring a long time to warm up the engine. The low temperature of the coolant also limits its heating effect on the LNG. In addition, the water pump of the LNG engine 3 needs to provide power for the cooling system circulation and sometimes circulate the coolant to the hydraulic retarder or transmission. For gas engines with EGR that meet China VI emission standards, coolant is also needed to dissipate heat from the EGR and exhaust gas venturi. This makes the water pump consume too much power, increases the vehicle's fuel consumption, reduces the service life of the LNG engine, and increases the failure rate.

[0052] The electronic control device 9 can compare the monitored LNG gas temperature, coolant temperature, and hot gas temperature output from the hot end pipe. When the hot gas temperature output from the hot end pipe is greater than the coolant temperature and the LNG gas temperature meets the requirement of being greater than -70℃, the electronic control device 9 controls the second control valve 61 to close, that is, to shut down the coolant circulation pipe 6. This can reduce the power of the water pump of the LNG engine 3, thereby achieving energy saving and emission reduction, and reducing some fuel consumption.

[0053] It should be noted that both the first control valve and the second control valve are electromagnetic control valves.

[0054] It should also be noted that traditional generators cool down by drawing in natural air through their air intake. However, in the high temperatures of summer, the temperature of natural air is still relatively high, so it cannot lower the internal temperature of the generator.

[0055] Example 2

[0056] This embodiment discloses an LNG commercial vehicle that applies an LNG commercial vehicle generator cooling system disclosed in Embodiment 1.

[0057] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A cooling system for an LNG commercial vehicle generator, characterized in that, include: The generator has two air inlets; The LNG engine's cylinders are connected to the vaporizer via a third pipeline, and the vaporizer is connected to the LNG tank via a second pipeline. A vortex tube consists of an inlet pipe, a cold end pipe, and a hot end pipe that are connected to each other. Compressed gas is introduced into the inlet pipe. The compressed gas entering the vortex tube is separated into hot gas and cold gas. The hot gas is discharged from the hot end pipe and the cold gas is discharged from the cold end pipe. The cold end pipe is connected to the first pipe, and the two air outlets of the first pipe are directly opposite the two air inlets of the generator to cool the internal components of the generator. The hot end pipe is connected to the fourth pipe, which is connected to the vaporizer to heat the liquefied gas inside the vaporizer.

2. The LNG commercial vehicle generator cooling system as described in claim 1, characterized in that, The cooling system also includes an air compressor, which is connected to the intake pipe and inputs compressed gas into the vortex tube.

3. The LNG commercial vehicle generator cooling system as described in claim 2, characterized in that, The cooling system also includes an air storage tank, which is located between the air compressor and the air inlet pipe and is connected to the air outlet of the air compressor; the air storage tank and the air inlet pipe are connected by a fifth pipeline; a first control valve is installed on the fifth pipeline.

4. The LNG commercial vehicle generator cooling system as described in claim 1, characterized in that, A coolant circulation pipeline is installed between the vaporizer and the LNG engine; a second control valve is installed on the coolant circulation pipeline.

5. The LNG commercial vehicle generator cooling system as described in claim 1, characterized in that, The vaporizer is equipped with a liquefied natural gas (LNG) pipe, with a coolant heat exchange pipe at the bottom and a hot gas heat exchange pipe at the top.

6. The LNG commercial vehicle generator cooling system as described in claim 5, characterized in that, The liquefied natural gas pipe is connected to the second and third pipelines at both ends, respectively; the inlet and outlet of the coolant heat exchange pipe are connected to the coolant circulation pipeline; one end of the hot gas heat exchange pipe is connected to the fourth pipeline, and the other end is connected to the exhaust pipeline.

7. The LNG commercial vehicle generator cooling system as described in claim 1, characterized in that, The cooling system also includes an electronic control device, which is connected to the generator via a signal line to obtain information about the generator's external load and internal temperature.

8. The LNG commercial vehicle generator cooling system as described in claim 7, characterized in that, Temperature sensors are installed on the second pipeline, the coolant circulation pipeline, and the fourth pipeline, and all temperature sensors are connected to the electronic control device.

9. The LNG commercial vehicle generator cooling system as described in claim 7, characterized in that, The first control valve and the second control valve are connected to the electronic control device.

10. An LNG commercial vehicle, characterized in that, The LNG commercial vehicle generator cooling system as described in any one of claims 1-9 is applied.

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