Compressed LNG (Liquefied Natural Gas) double-temperature-control-system hydraulic excavator

Abstract

The utility model relates to the technical field of excavators, in particular to a compressed LNG (liquefied natural gas) double-temperature-control-system hydraulic excavator, which comprises a compressed LNG heat exchanger for hydraulic oil, a water-cooled radiator for an engine, a compressed LNG heat exchanger for the engine and a controller. The low-temperature energy of compressed LNG is used for replacing a traditional air cooling heat dissipation device to cool hydraulic oil, so that the normal temperature of the hydraulic oil is guaranteed; a compressed LNG natural gas heat exchanger for an engine is additionally arranged on the basis of a water-cooled radiator for the engine, low-temperature energy of compressed LNG natural gas participates in cooling of the engine, when the weather is cold, only the water-cooled radiator for the engine is used for cooling the engine, and when the temperature reaches the set highest working temperature, the engine is cooled through the compressed LNG natural gas heat exchanger. And the controller controls the compressed LNG natural gas heat exchanger for the engine to operate to regulate and control the temperature of the engine.

Description

Technical Field

[0001] The utility model relates to the technical field of excavators, in particular to a hydraulic excavator with a double temperature control system for compressed LNG natural gas. Background Art

[0002] Conventional hydraulic excavators mainly use diesel as fuel, which not only consumes a lot of fuel, but also emits a lot of pollutants from the tail gas. Usually, the highest pollutant emission standard can only meet the National IV emission standard. The labeling of diesel fuel is also difficult to ensure during the construction of engineering machinery, especially when using inferior diesel, it cannot meet the various requirements of energy conservation and emission reduction. In addition, most of the hydraulic oils of existing hydraulic excavators do not have a heat dissipation device, and use natural heat dissipation. When the working intensity of the excavator is too high, it is easy to cause the hydraulic oil temperature to rise, causing the hydraulic excavator to be powerless or the hydraulic components to be damaged; the radiator of the hydraulic excavator engine is also easily blocked by dust, and the heat dissipation effect is poor, resulting in excessively high coolant temperature. Frequent inspection and cleaning of the heat sink is required, which is time-consuming and labor-intensive, and also has a certain impact on the working efficiency of the hydraulic excavator. Summary of the invention

[0003] In order to overcome the above technical problems, the utility model provides a hydraulic excavator with a compressed LNG natural gas dual temperature control system.

[0004] The utility model provides a compressed LNG natural gas dual temperature control system hydraulic excavator adopts the following technical solutions:

[0005] A compressed LNG natural gas dual temperature control system hydraulic excavator, comprising a hydraulic excavator body, a bucket working device is installed at the front end of the hydraulic excavator body, a walking device is installed at the bottom of the hydraulic excavator body, and also comprises a compressed LNG natural gas supply system, an engine, a hydraulic oil pump, a hydraulic oil tank and a temperature control system, wherein the compressed LNG natural gas supply system is arranged on the hydraulic excavator body, the engine, the hydraulic oil pump, the hydraulic oil tank and the temperature control system are all arranged inside the hydraulic excavator body, the engine drive is connected to the hydraulic oil pump, the hydraulic oil pump pipeline is connected to the bucket working device and the hydraulic oil tank, the temperature control system includes It includes a compressed LNG natural gas heat exchanger for hydraulic oil, a water-cooled radiator for the engine, a compressed LNG natural gas heat exchanger for the engine and a controller. The compressed LNG natural gas heat exchanger for hydraulic oil, the water-cooled radiator for the engine and the compressed LNG natural gas heat exchanger for the engine are all electrically connected to the controller. The compressed LNG natural gas heat exchanger for hydraulic oil is connected to the compressed LNG natural gas supply system and the hydraulic oil tank through a pipeline. The water-cooled radiator for the engine is connected to the compressed LNG natural gas heat exchanger pipeline for the engine. The compressed LNG natural gas heat exchanger pipeline for the engine is connected to the compressed LNG natural gas supply system and the engine.

[0006] By adopting the above technical scheme, a compressed LNG natural gas heat exchanger is set for hydraulic oil, and the low temperature energy of compressed LNG natural gas is used to replace the traditional air-cooled heat sink to cool the hydraulic oil. The controller can be adjusted at any time according to the working condition of the hydraulic excavator to ensure that the temperature of the hydraulic oil is normal, thereby avoiding the situation where the hydraulic excavator is powerless or the hydraulic components are damaged; a compressed LNG natural gas heat exchanger for the engine is added on the basis of the water-cooled radiator for the engine, and the low temperature energy of compressed LNG natural gas is used to participate in the cooling of the engine. When the weather is cold, only the water-cooled radiator for the engine is used to cool the engine. When the temperature reaches the set maximum operating temperature, the controller controls the operation of the compressed LNG natural gas heat exchanger for the engine to regulate the temperature of the engine.

[0007] Preferably, an electromagnetic three-way valve is provided on the connecting pipeline between the compressed LNG natural gas heat exchanger for hydraulic oil and the compressed LNG natural gas supply system, and a temperature sensor is provided on the connecting pipeline between the hydraulic oil pump and the hydraulic oil tank, and the electromagnetic three-way valve and the temperature sensor are both electrically connected to the controller.

[0008] By adopting the above technical solution, a temperature sensor is provided on the connecting pipeline between the hydraulic oil pump and the hydraulic oil tank to monitor the temperature of the hydraulic oil in real time. When the hydraulic oil reaches the set maximum working temperature, the controller receives the signal and controls the electromagnetic three-way valve to operate the compressed LNG natural gas heat exchanger for the hydraulic oil. The low-temperature compressed LNG natural gas enters the compressed LNG natural gas heat exchanger for the hydraulic oil to participate in heat exchange and cool the hydraulic oil.

[0009] Preferably, an electromagnetic three-way valve No. 2 is provided on the connecting pipeline between the compressed LNG natural gas heat exchanger for the engine and the compressed LNG natural gas supply system, an inlet temperature sensor is provided on the connecting pipeline between the outlet of the water-cooled radiator for the engine and the inlet of the compressed LNG natural gas heat exchanger for the engine, and a loop temperature sensor is provided on the connecting pipeline between the inlet of the water-cooled radiator for the engine and the outlet of the compressed LNG natural gas heat exchanger for the engine, and the electromagnetic three-way valve No. 2, the inlet temperature sensor and the loop temperature sensor are all electrically connected to the controller.

[0010] By adopting the above technical scheme, an inlet temperature sensor is provided on the connecting pipeline between the outlet of the water-cooled radiator of the engine and the inlet of the compressed LNG natural gas heat exchanger for the engine, and a loop temperature sensor is provided on the connecting pipeline between the inlet of the water-cooled radiator of the engine and the outlet of the compressed LNG natural gas heat exchanger for the engine. When the inlet temperature sensor detects that the coolant temperature reaches the set maximum operating temperature, the controller receives the signal and controls the electromagnetic three-way valve 2 on the connecting pipeline between the compressed LNG natural gas heat exchanger for the engine and the compressed LNG natural gas supply system to operate the compressed LNG natural gas heat exchanger for the engine; when the loop temperature sensor detects that the coolant temperature is lower than the set value, the controller receives the signal and controls the electromagnetic three-way valve 2 on the connecting pipeline between the compressed LNG natural gas heat exchanger for the engine and the compressed LNG natural gas supply system to stop the operation of the compressed LNG natural gas heat exchanger for the engine.

[0011] Preferably, the compressed LNG natural gas supply system includes a compressed LNG natural gas storage tank, a fixed base, a protection frame and a hydraulic self-lifting device, the fixed base is fixedly installed on the hydraulic excavator body, the protection frame and the fixed base are connected via a clamping seat, the compressed LNG natural gas storage tank is fixedly arranged in the protection frame, the hydraulic self-lifting device is arranged on the fixed base, and the hydraulic self-lifting device is connected to the protection frame via a steel wire rope.

[0012] Preferably, the hydraulic self-lifting device includes a hydraulic winch, a pulley block, a variable-stroke lifting bracket and a hydraulic cylinder, the hydraulic winch is fixedly mounted on a fixed base, the pulley block is fixedly mounted on a variable-stroke lifting bracket, the steel wire rope is laid on the variable-stroke lifting bracket, the protective frame is connected to the hydraulic winch via the steel wire rope and the pulley block, the variable-stroke lifting bracket is rotatably connected to the fixed base, the hydraulic cylinder is rotatably connected to the fixed base, and the protruding end of the hydraulic cylinder is rotatably connected to the middle part of the variable-stroke lifting bracket.

[0013] By adopting the above technical solution and setting a hydraulic self-lifting device for the compressed LNG natural gas storage tank, when compressed LNG natural gas needs to be filled, the socket connecting the protection frame and the fixed base is opened, and the hydraulic winch starts to work to lift the protection frame. At the same time, the hydraulic cylinder extends to push the variable stroke lifting bracket forward. At this time, the compressed LNG natural gas storage tank and the protection frame can be lifted and transported to the gas filling station for filling with fuel, so that the compressed LNG natural gas can meet the use of non-road engineering machinery and equipment.

[0014] Preferably, it further comprises an exhaust gas emission treatment device, wherein the exhaust gas emission treatment device comprises a post-particle trap and an adsorption device, and the post-particle trap and the adsorption device are connected to the engine pipeline in sequence.

[0015] By adopting the above technical solution, only a post-particulate collector and an adsorption device are installed on the exhaust gas emission treatment device. By controlling the source and using compressed LNG natural gas clean energy, a more environmentally friendly and efficient emission standard is achieved, simplifying the setting of the exhaust gas emission treatment device.

[0016] Preferably, it also includes a compressed LNG natural gas monitoring system, and the compressed LNG natural gas monitoring system is arranged on the compressed LNG natural gas storage tank.

[0017] By adopting the above technical solution and installing a compressed LNG natural gas monitoring system on the compressed LNG natural gas storage tank, it is possible to monitor the liquid level, temperature, pressure and other parameters in the compressed LNG natural gas storage tank in real time, which can not only provide early warning and improve safety, but also more accurately regulate the compressed LNG natural gas.

[0018] In summary, the utility model has the following beneficial effects:

[0019] 1. The utility model is a hydraulic excavator with a compressed LNG natural gas dual temperature control system. By using compressed LNG natural gas instead of traditional diesel as fuel, on the one hand, the cost of compressed LNG natural gas is lower than that of diesel, which can save costs. On the other hand, compressed LNG natural gas has excellent emission performance and can save energy and reduce emissions. By using the low-temperature energy of compressed LNG natural gas to replace the traditional air-cooled heat sink to cool the hydraulic oil, the controller can be adjusted at any time according to the working conditions of the hydraulic excavator to ensure that the temperature of the hydraulic oil is normal, thereby avoiding the situation where the hydraulic excavator is powerless or the hydraulic components are damaged. On the basis of the water-cooled radiator of the engine, a compressed LNG natural gas heat exchanger for the engine is added, and the low-temperature energy of compressed LNG natural gas is used to participate in the cooling of the engine. When the weather is cold, only the water-cooled radiator of the engine is used to cool the engine. When the temperature reaches the set maximum operating temperature, the controller controls the operation of the compressed LNG natural gas heat exchanger for the engine to regulate the temperature of the engine.

[0020] 2. The utility model is a hydraulic excavator with a compressed LNG natural gas dual temperature control system. A temperature sensor 1 is arranged on the connecting pipeline between the hydraulic oil pump and the hydraulic oil tank to monitor the temperature of the hydraulic oil in real time. When the hydraulic oil reaches the set maximum working temperature, the controller receives a signal and controls the electromagnetic three-way valve 1 to operate the compressed LNG natural gas heat exchanger for the hydraulic oil, and the low-temperature compressed LNG natural gas enters the compressed LNG natural gas heat exchanger for the hydraulic oil to participate in heat exchange and cool the hydraulic oil; an inlet temperature sensor and a loop temperature sensor are arranged on the connecting pipeline between the water-cooled radiator of the engine and the compressed LNG natural gas heat exchanger for the engine. When the inlet temperature sensor detects that the coolant temperature reaches the set maximum working temperature, the controller receives a signal and controls the electromagnetic three-way valve 2 to operate the compressed LNG natural gas heat exchanger for the engine; when the loop temperature sensor detects that the coolant temperature is lower than the set value, the controller receives a signal and controls the electromagnetic three-way valve 2 to stop the compressed LNG natural gas heat exchanger for the engine from running.

[0021] 3. The utility model is a hydraulic excavator with a compressed LNG natural gas dual temperature control system. By setting a hydraulic self-lifting device for a compressed LNG natural gas storage tank, when compressed LNG natural gas needs to be filled, the socket connecting the protection frame and the fixed base is opened, and the hydraulic winch starts to work to lift the protection frame. At the same time, the hydraulic cylinder extends to push the variable stroke lifting bracket forward. At this time, the compressed LNG natural gas storage tank and the protection frame can be lifted and transported to a gas filling station for filling with fuel, so that compressed LNG natural gas can meet the use of non-road engineering machinery and equipment.

[0022] 4. The utility model is a compressed LNG natural gas dual temperature control system hydraulic excavator, which is only equipped with a post-particle catcher and an adsorption device on the exhaust emission treatment device. By controlling from the source and using compressed LNG natural gas clean energy, it achieves more environmentally friendly and efficient emission standards, simplifying the setting of the exhaust emission treatment device; a compressed LNG natural gas monitoring system is set on the compressed LNG natural gas storage tank, which can monitor the liquid level, temperature, pressure and other parameters in the compressed LNG natural gas storage tank in real time, which can not only provide early warning and improve safety, but also can more accurately regulate the compressed LNG natural gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the front view of a hydraulic excavator with a dual temperature control system for compressed LNG natural gas;

[0024] Figure 2 This is a rear view of a hydraulic excavator with a compressed LNG natural gas dual temperature control system;

[0025] Figure 3 Schematic diagram of the temperature control system of compressed LNG natural gas for hydraulic oil of hydraulic excavator;

[0026] Figure 4 This is a schematic diagram of the compressed LNG natural gas temperature control system for the engine of a hydraulic excavator;

[0027] Figure 5 Schematic diagram of compressed LNG natural gas supply system.

[0028] Explanation of the reference numerals: 1. Hydraulic excavator body; 2. Bucket working device; 3. Travel device; 4. Compressed LNG natural gas supply system; 41. Compressed LNG natural gas storage tank; 42. Fixed base; 43. Protection frame; 44. Hydraulic self-hoisting device; 441. Hydraulic winch; 442. Pulley block; 443. Variable stroke hoisting bracket; 444. Hydraulic cylinder; 5. Engine; 6. Hydraulic oil pump; 7. Hydraulic oil tank; 8. Temperature control system; 81. Compressed LNG natural gas heat exchanger for hydraulic oil; 811. Solenoid three-way valve one; 812. Temperature sensor one; 82. Water-cooled radiator for engine; 83. Compressed LNG natural gas heat exchanger for engine; 831. Solenoid three-way valve two; 832. Inlet temperature sensor; 833. Loop temperature sensor; 84. Controller; 9. Exhaust emission treatment device; 91. Post-particle trap; 92. Adsorption device; 10. Compressed LNG natural gas monitoring system. DETAILED DESCRIPTION

[0029] The following is combined with Figure 1-5 The utility model is described in further detail.

[0030] This embodiment discloses a hydraulic excavator with a dual temperature control system for compressed LNG natural gas. Figure 1-Figure 5, including a hydraulic excavator body 1, a bucket working device 2 is installed at the front end of the hydraulic excavator body 1, a walking device 3 is installed at the bottom of the hydraulic excavator body 1, and also includes a compressed LNG natural gas supply system 4, an engine 5, a hydraulic oil pump 6, a hydraulic oil tank 7 and a temperature control system 8. The compressed LNG natural gas supply system 4 is arranged on the hydraulic excavator body 1, and the engine 5, the hydraulic oil pump 6, the hydraulic oil tank 7 and the temperature control system 8 are all arranged inside the hydraulic excavator body 1. The compressed LNG natural gas supply system 4 is connected to the engine 5 through a pipeline to provide compressed LNG natural gas to the engine 5. The engine 5 is driven to connect to the hydraulic oil pump 6. The hydraulic oil pump 6 sucks the hydraulic oil from the hydraulic oil tank 7 through the oil supply pipeline, and then makes the hydraulic oil flow through the pressure. Under the drive of the hydraulic oil pump 6, the hydraulic oil passes into the hydraulic cylinder, thereby driving the bucket working device 2 to move. The temperature control system 8 includes a compressed LNG natural gas heat exchanger 81 for hydraulic oil, a water-cooled radiator 82 for the engine, a compressed LNG natural gas heat exchanger 83 for the engine and a controller 84. The compressed LNG natural gas heat exchanger 81 for hydraulic oil is respectively connected to the compressed LNG natural gas supply system 4 and the hydraulic oil tank 7 by pipelines, that is, the compressed LNG natural gas heat exchanger 81 for hydraulic oil is connected to the compressed LNG natural gas supply system 4 and the hydraulic oil tank 7 by pipelines. The compressed LNG natural gas heat exchanger 81 can realize the heat energy exchange between the compressed LNG natural gas and the hydraulic oil, so as to meet the specific temperature conditions required by the hydraulic oil pump 6 for the hydraulic oil, so as to avoid the hydraulic excavator from being weak or the hydraulic components being damaged. The connecting pipeline between the compressed LNG natural gas heat exchanger 81 for the hydraulic oil and the compressed LNG natural gas supply system 4 is provided with an electromagnetic three-way valve 811 to control the on-off of the compressed LNG natural gas heat exchanger 81 for the hydraulic oil and the compressed LNG natural gas supply system 4. The connecting pipeline between the hydraulic oil pump 6 and the hydraulic oil tank 7 is provided with a temperature sensor 812 to monitor the temperature in real time. To measure the temperature of the hydraulic oil, the electromagnetic three-way valve 811 and the temperature sensor 812 are both electrically connected to the controller 84. When the temperature of the hydraulic oil reaches the set maximum working temperature, the temperature sensor 812 transmits a signal to the controller 84. The controller 84 controls the electromagnetic three-way valve 811 to connect the compressed LNG natural gas heat exchanger 81 for hydraulic oil with the compressed LNG natural gas supply system 4. The low-temperature compressed LNG natural gas enters the compressed LNG natural gas heat exchanger 81 for hydraulic oil to participate in heat exchange, so as to cool the hydraulic oil. The compressed LNG natural gas after heat exchange is also supplied to the engine 5 as fuel.The engine water-cooled radiator 82 is connected to the engine compressed LNG natural gas heat exchanger 83 by pipeline, and the engine compressed LNG natural gas heat exchanger 83 is respectively connected to the compressed LNG natural gas supply system 4 and the engine 5 by pipeline, that is, the engine compressed LNG natural gas heat exchanger 83 can realize the heat energy exchange between the compressed LNG natural gas and the engine coolant, so that the engine coolant maintains a stable temperature condition, and an electromagnetic three-way valve 831 is arranged on the connecting pipeline between the engine compressed LNG natural gas heat exchanger 83 and the compressed LNG natural gas supply system 4 to open and close the engine compressed LNG natural gas heat exchanger 83 and the compressed LNG natural gas supply system 4, an inlet temperature sensor 832 is arranged on the connecting pipeline between the outlet of the engine water-cooled radiator 82 and the inlet of the engine compressed LNG natural gas heat exchanger 83, and a loop temperature sensor 833 is arranged on the connecting pipeline between the inlet of the engine water-cooled radiator 82 and the outlet of the engine compressed LNG natural gas heat exchanger 83 to monitor the temperature of the engine coolant in real time. The second three-way valve 831, the inlet temperature sensor 832 and the loop temperature sensor 833 are all electrically connected to the controller 84. When the weather is cold, the engine uses the water-cooled radiator 82 to cool the engine 5. When the inlet temperature sensor 832 detects that the engine coolant temperature reaches the set maximum operating temperature, the signal is transmitted to the controller 84. The controller 84 controls the electromagnetic three-way valve 831 to connect the engine compressed LNG natural gas heat exchanger 83 with the compressed LNG natural gas supply system 4. The low-temperature compressed LNG natural gas enters the engine compressed LNG natural gas heat exchanger 83 to participate in heat exchange, cool the engine coolant, and the compressed LNG natural gas after heat exchange is supplied to the engine 5 as fuel; when the loop temperature sensor 833 detects that the engine coolant temperature is lower than the set value, the controller 84 receives the signal and controls the electromagnetic three-way valve 831 to disconnect the engine compressed LNG natural gas heat exchanger 83 from the compressed LNG natural gas supply system 4, and only uses the engine water-cooled radiator 82 to cool the engine 5. ;

[0031] Among them, Figure 1-Figure 5As shown, the compressed LNG natural gas supply system 4 includes a compressed LNG natural gas storage tank 41, a fixed base 42, a protection frame 43 and a hydraulic self-hoisting device 44. The fixed base 42 is fixedly installed on the hydraulic excavator body 1, the protection frame 43 is connected to the fixed base 42 through a socket, the compressed LNG natural gas storage tank 41 is fixedly arranged in the protection frame 43, the hydraulic self-hoisting device 44 includes a hydraulic winch 441, a pulley block 442, a variable stroke hoisting bracket 443 and a hydraulic cylinder 444, the hydraulic winch 441 is fixedly installed on the fixed base 42, the pulley block 442 is fixedly installed on the variable stroke hoisting bracket 443, the wire rope is laid on the variable stroke hoisting bracket 443, the protection frame 43 is connected to the hydraulic winch 441 through the wire rope and the pulley block 442, the variable stroke hoisting bracket 443 is rotatably connected to the fixed base 42, the hydraulic cylinder 444 is rotatably connected to the fixed base 42, and the extended end of the hydraulic cylinder 444 is rotatably connected to the middle part of the variable stroke hoisting bracket 443. When compressed LNG natural gas needs to be filled, the socket connecting the protection frame 43 and the fixed base 42 is opened, and the hydraulic winch 441 starts to work to lift the protection frame 43. At the same time, the hydraulic cylinder 444 extends to push the variable stroke lifting bracket 443 forward. At this time, the compressed LNG natural gas storage tank 41 and the protection frame 43 can be lifted away from the fixed base 42 and transferred to the gas filling station for filling with fuel, so that the compressed LNG natural gas can meet the use of non-road engineering machinery and equipment.

[0032] Among them, Figure 1-Figure 5 As shown, a compressed LNG natural gas dual temperature control system hydraulic excavator also includes an exhaust gas emission treatment device 9 and a compressed LNG natural gas monitoring system 10. The exhaust gas emission treatment device 9 includes a post-particle trap 91 and an adsorption device 92. The post-particle trap 91 and the adsorption device 92 are connected to the engine 5 pipeline in sequence. After the compressed LNG natural gas is burned in the engine 5, the post-particle trap 91 captures the particulate emission substances in the exhaust gas before they enter the atmosphere. Then the adsorption device 92 uses activated carbon particles to adsorb the organic gas in the clean exhaust gas, and the exhaust gas is treated to meet the emission standards before being discharged, so that the device meets environmental protection requirements; the compressed LNG natural gas monitoring system 10 is arranged on the compressed LNG natural gas storage tank 41. The compressed LNG natural gas monitoring system 10 monitors the liquid level, temperature, pressure and other parameters in the compressed LNG natural gas storage tank 41 in real time through sensors, data collection instruments and other equipment, which can not only provide early warning and improve safety, but also more accurately regulate the compressed LNG natural gas to participate in the cooling of the hydraulic oil and the engine 5, thereby realizing accurate temperature regulation of the engine 5 and the hydraulic oil.

[0033] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A compressed LNG natural gas dual temperature control system hydraulic excavator, comprising a hydraulic excavator body (1), a bucket working device (2) being installed at the front end of the hydraulic excavator body (1), and a walking device (3) being installed at the bottom of the hydraulic excavator body (1), characterized in that: The invention comprises a compressed LNG natural gas supply system (4), an engine (5), a hydraulic oil pump (6), a hydraulic oil tank (7) and a temperature control system (8), wherein the compressed LNG natural gas supply system (4) is arranged on a hydraulic excavator body (1), the engine (5), the hydraulic oil pump (6), the hydraulic oil tank (7) and the temperature control system (8) are all arranged inside the hydraulic excavator body (1), the engine (5) is driven and connected to the hydraulic oil pump (6), the hydraulic oil pump (6) is connected to the bucket working device (2) and the hydraulic oil tank (7) through a pipeline, and the temperature control system (8) comprises a compressed LNG natural gas heat exchanger (81) for hydraulic oil, a water-cooled radiator (82) for the engine, and a temperature control system (8) for the engine. A compressed LNG natural gas heat exchanger (83) and a controller (84); the compressed LNG natural gas heat exchanger (81) for hydraulic oil, the water-cooled radiator (82) for the engine and the compressed LNG natural gas heat exchanger (83) for the engine are all electrically connected to the controller (84); the compressed LNG natural gas heat exchanger (81) for hydraulic oil is connected via a pipeline to a compressed LNG natural gas supply system (4) and a hydraulic oil tank (7); the water-cooled radiator (82) for the engine is connected via a pipeline to a compressed LNG natural gas heat exchanger (83) for the engine; and the compressed LNG natural gas heat exchanger (83) for the engine is connected via a pipeline to a compressed LNG natural gas supply system (4) and an engine (5).

2. A hydraulic excavator with a compressed LNG natural gas dual temperature control system according to claim 1, characterized in that: An electromagnetic three-way valve (811) is provided on the connecting pipeline between the compressed LNG natural gas heat exchanger (81) for hydraulic oil and the compressed LNG natural gas supply system (4), and a temperature sensor (812) is provided on the connecting pipeline between the hydraulic oil pump (6) and the hydraulic oil tank (7). The electromagnetic three-way valve (811) and the temperature sensor (812) are both electrically connected to the controller (84).

3. The hydraulic excavator with a compressed LNG natural gas dual temperature control system according to claim 1, characterized in that: A second electromagnetic three-way valve (831) is provided on the connecting pipeline between the compressed LNG natural gas heat exchanger (83) for the engine and the compressed LNG natural gas supply system (4); an inlet temperature sensor (832) is provided on the connecting pipeline between the outlet of the water-cooled radiator (82) for the engine and the inlet of the compressed LNG natural gas heat exchanger (83) for the engine; a loop temperature sensor (833) is provided on the connecting pipeline between the inlet of the water-cooled radiator (82) for the engine and the outlet of the compressed LNG natural gas heat exchanger (83) for the engine; and the second electromagnetic three-way valve (831), the inlet temperature sensor (832) and the loop temperature sensor (833) are all electrically connected to the controller (84).

4. The compressed LNG natural gas dual temperature control system hydraulic excavator according to claim 1, characterized in that: The compressed LNG natural gas supply system (4) comprises a compressed LNG natural gas storage tank (41), a fixed base (42), a protection frame (43) and a hydraulic self-lifting device (44); the fixed base (42) is fixedly mounted on a hydraulic excavator body (1); the protection frame (43) and the fixed base (42) are connected via a clamping seat; the compressed LNG natural gas storage tank (41) is fixedly arranged in the protection frame (43); the hydraulic self-lifting device (44) is arranged on the fixed base (42); and the hydraulic self-lifting device (44) is connected to the protection frame (43) via a steel wire rope.

5. The compressed LNG natural gas dual temperature control system hydraulic excavator according to claim 4, characterized in that: The hydraulic self-lifting device (44) comprises a hydraulic winch (441), a pulley block (442), a variable-stroke lifting bracket (443) and a hydraulic cylinder (444); the hydraulic winch (441) is fixedly mounted on a fixed base (42); the pulley block (442) is fixedly mounted on a variable-stroke lifting bracket (443); the steel wire rope is laid on the variable-stroke lifting bracket (443); the protection frame (43) is connected to the hydraulic winch (441) via the steel wire rope and the pulley block (442); the variable-stroke lifting bracket (443) is rotatably connected to the fixed base (42); the hydraulic cylinder (444) is rotatably connected to the fixed base (42); and the extended end of the hydraulic cylinder (444) is rotatably connected to the middle part of the variable-stroke lifting bracket (443).

6. The compressed LNG natural gas dual temperature control system hydraulic excavator according to claim 1, characterized in that: It also includes an exhaust gas emission treatment device (9), the exhaust gas emission treatment device (9) including a post-particle trap (91) and an adsorption device (92), the post-particle trap (91) and the adsorption device (92) being connected to the engine (5) pipeline in sequence.

7. The compressed LNG natural gas dual temperature control system hydraulic excavator according to claim 4, characterized in that: It also comprises a compressed LNG natural gas monitoring system (10), wherein the compressed LNG natural gas monitoring system (10) is arranged on a compressed LNG natural gas storage tank (41).

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