A liquid ammonia high-pressure injection experimental system and experimental method

Abstract

The present invention discloses a liquid ammonia high-pressure injection experimental system and an experimental method. The liquid ammonia high-pressure injection experimental system includes an ammonia gas storage tank, a gas booster pump, a gas-liquid booster pump, an air compressor, a constant volume bomb, a common rail pipe, a nozzle, a constant volume bomb temperature and pressure operation console, an ECU electronic control unit, and a host computer. The ammonia gas storage tank, the gas booster pump, the gas-liquid booster pump, the common rail pipe, and the nozzle are sequentially connected through pipelines. The air compressor is connected to the gas booster pump and the gas-liquid booster pump through pipelines. The ECU electronic control unit is electrically connected to the host computer, the common rail pipe, and the nozzle. The nozzle is fixed on the constant volume bomb. A temperature sensor and a pressure sensor electrically connected to the temperature and pressure operation console are arranged in the constant volume bomb. A heater is arranged on the constant volume bomb and is communicated with at least one gas storage tank. The present invention performs secondary pressurization on ammonia through the gas booster pump and the gas-liquid booster pump, so that the increased liquid ammonia reaches a predetermined injection pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure injection, and specifically to a liquid ammonia high-pressure injection experimental system and an experimental method. Background Art

[0002] High-pressure injection can be widely applied in agricultural irrigation, medical sugar coating spraying, chemical industry, and internal combustion engine spray combustion. Among them, the application in the field of internal combustion engines is the most extensive. The quality of the atomization and evaporation characteristics of high-pressure jet spray directly affects the quality of the ignition and combustion process in the combustion chamber and plays a major decisive role in the subsequent soot formation. At present, with the intensification of environmental pollution, the high-pressure jet combustion of traditional fossil fuels will bring serious carbon emissions, which is particularly obvious in diesel engines. Therefore, it is urgent to find renewable alternative clean fuels. As a representative of green renewable clean fuels, ammonia, from a chemical structure perspective, does not produce carbon emissions during combustion. Therefore, the research on ammonia in engines has become a mainstream trend.

[0003] From the physical and chemical properties of ammonia, it exists in a gaseous state at normal temperature and pressure, and its saturated vapor pressure at room temperature is about 1 MPa. That is, when ammonia gas is pressurized to 1 MPa, a phase change from gaseous to liquid occurs. Therefore, due to the existence of phase change, it is difficult to use the pressurization methods of traditional liquid fuels or gas fuels to pressurize ammonia fuel to reach the predetermined injection pressure. At present, the development of internal combustion engines is closely related to the increase in injection pressure, which affects the high-pressure injection of ammonia fuel and thus affects the performance of internal combustion engines. Summary of the Invention

[0004] Aiming at the problem that it is difficult to pressurize ammonia fuel to reach the predetermined injection pressure in the existing high-pressure injection system, the present invention provides a liquid ammonia high-pressure injection experimental system and an experimental method, which perform secondary pressurization on ammonia gas through a gas booster pump and a gas-liquid booster pump to make the increased liquid ammonia reach the predetermined injection pressure.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A high-pressure ammonia injection experimental system includes an ammonia gas storage tank, a gas booster pump, a gas-liquid booster pump, an air compressor, a constant volume bomb, a common rail pipe, a nozzle, a constant volume bomb temperature and pressure operation console, an ECU electronic control unit, and a host computer. The ammonia gas storage tank, the gas booster pump, the gas-liquid booster pump, the common rail pipe, and the nozzle are sequentially connected through pipelines. The air compressor is connected to the gas booster pump and the gas-liquid booster pump through pipelines to provide driving gas for the gas booster pump and the gas-liquid booster pump. The ECU electronic control unit is electrically connected to the host computer, the common rail pipe, and the nozzle. The host computer controls the on-off of the common rail pipe and the nozzle through the ECU electronic control unit. The nozzle is fixed on the constant volume bomb. A temperature sensor and a pressure sensor electrically connected to the temperature and pressure operation console are arranged in the constant volume bomb, which are respectively used to detect the temperature and air pressure of the constant volume bomb. A heater is arranged on the constant volume bomb and is connected to at least one gas storage tank. The gas storage tank and the heater are both controlled by the constant volume bomb temperature and pressure operation console.

[0007] Further, a gas-liquid separator is arranged between the gas booster pump and the gas-liquid booster pump. The outlet of the gas booster pump is communicated with the inlet of the gas-liquid separator, the inlet of the gas-liquid booster pump is communicated with the liquid outlet of the gas-liquid separator, and the gas outlet at the top of the gas-liquid separator is communicated with the inlet of the gas booster pump.

[0008] Further, the pipeline communicated with the outlet of the gas booster pump is a coiled pipe, and the coiled pipe is located in a cooling box filled with coolant for heat exchange.

[0009] Further, an exhaust gas storage tank is also included. Exhaust pipelines are provided on the gas booster pump, the gas-liquid booster pump, the common rail pipe, and the constant volume bomb and are respectively communicated with the exhaust gas storage tank. A first unloading valve, a second unloading valve, a second high-pressure needle valve, and an exhaust valve are respectively arranged on the exhaust pipelines of the gas booster pump, the gas-liquid booster pump, the common rail pipe, and the constant volume bomb.

[0010] Further, a vacuum pump is also included. The vacuum pump is respectively communicated with the gas-liquid booster pump and the common rail pipe. A first high-pressure needle valve is arranged on the outlet pipeline of the vacuum pump to control the on-off of the outlet pipeline of the vacuum pump.

[0011] Further, the ammonia gas storage tank is arranged in an ammonia explosion-proof cabinet.

[0012] Further, two gas storage tanks are connected to the constant volume bomb, which are respectively filled with nitrogen and air.

[0013] Further, a first driving gas switch, a first driving gas pressure regulating valve and a first driving gas pressure gauge are provided on the pipeline between the gas booster pump and the air compressor, which are respectively used to control the on-off of the pipeline between the gas booster pump and the air compressor, adjust the air pressure of the driving gas of the gas booster pump and detect the air pressure of the driving gas of the gas booster pump; a first high-pressure pressure gauge and a high-pressure outlet valve are provided on the outlet pipeline of the gas booster pump, which are respectively used to detect the pressure of the liquid ammonia after being boosted by the gas booster pump and control the on-off of the outlet pipeline of the gas booster pump;

[0014] A second driving gas switch, a second driving gas pressure regulating valve and a second driving gas pressure gauge are provided on the pipeline between the gas-liquid booster pump and the air compressor, which are respectively used to control the on-off of the pipeline between the gas-liquid booster pump and the air compressor, adjust the air pressure of the driving gas of the gas-liquid booster pump and detect the air pressure of the driving gas of the gas-liquid booster pump; a medium inlet switch is provided on the inlet pipeline of the gas-liquid booster pump, which is used to control the on-off of the liquid ammonia entering the gas-liquid booster pump; a second high-pressure pressure gauge and a fourth high-pressure needle valve are provided on the outlet pipeline of the gas-liquid booster pump, which are respectively used to detect the pressure of the liquid ammonia after being boosted by the gas-liquid booster pump and control the on-off of the outlet pipeline of the gas-liquid booster pump;

[0015] A third high-pressure pressure gauge is provided on the common rail pipe, which is used to detect the pressure of the liquid ammonia in the common rail pipe; a third high-pressure needle valve is provided on the pipeline between the common rail pipe and the nozzle, which is used to manually control the opening and closing of the injection.

[0016] An exhaust valve is provided on the pipeline between the constant volume bomb and the exhaust memory, which is used to control the exhaust and unloading of the constant volume bomb.

[0017] An experimental method for a liquid ammonia high-pressure injection experimental system includes the following steps:

[0018] S1. Open the medium inlet switch and the fourth high-pressure needle valve to make the gas-liquid booster pump and the common rail pipe in a connected state. Open the first high-pressure needle valve on the outlet pipeline of the vacuum pump and start the vacuum pump to extract the residual gas in the gas-liquid booster pump, the common rail pipe and the pipeline therebetween to achieve a vacuum state. Then close the vacuum pump, the first high-pressure needle valve, the medium inlet switch and the fourth high-pressure needle valve;

[0019] S2. Open the ammonia gas cylinder, and at the same time open the high-pressure outlet valve, the gas-liquid separator, the medium inlet switch and the fourth high-pressure needle valve. At this time, the first unloading valve and the second unloading valve remain closed;

[0020] S3. Open the air compressor, open the first driving gas switch and start the gas booster pump to perform primary boosting on the ammonia gas to convert it into liquid ammonia. Adjust the first driving gas pressure regulating valve to control the indication value of the first high-pressure pressure gauge to be not less than MPa;

[0021] S4. Open the second driving gas switch and start the gas-liquid booster pump to further boost the pressure of liquid ammonia. Adjust the second driving gas pressure regulating valve to control the indication value of the second high-pressure pressure gauge to reach the target injection pressure;

[0022] S5. The temperature sensor and pressure sensor on the constant volume bomb monitor the temperature and air pressure of the constant volume bomb, and adjust the temperature and air pressure in the constant volume bomb to the target values through the constant volume bomb temperature and pressure control operation console;

[0023] S6. Set the target frequency and pulse width of liquid ammonia injection on the upper computer. Open the third high-pressure needle valve. According to the target frequency and pulse width, the upper computer controls the on-off of the common rail pipe and the nozzle through the ECU electronic control unit, and then injects it into the constant volume bomb at the target frequency and pulse width;

[0024] S7. After the injection is completed, close the first driving gas switch and the second driving gas switch; open the exhaust valve to discharge the gas in the constant volume bomb into the exhaust storage; close the ammonia gas cylinder and the air compressor. According to the principle of first high-pressure unloading and then low-pressure unloading, first open the second unloading valve to discharge the residual liquid ammonia / ammonia gas in the gas-liquid booster pump into the exhaust storage; then open the first unloading valve to discharge the residual liquid ammonia / ammonia gas in the gas booster pump into the exhaust storage; open the second high-pressure needle valve to discharge the residual liquid ammonia / ammonia gas in the common rail pipe into the exhaust storage, so as to realize the unloading and exhaust of the constant volume bomb, the gas-liquid booster pump, the gas booster pump, and the common rail pipe.

[0025] Further, in step S3, the adjustment range of the indication value of the first driving gas pressure gauge is 0.1 - 0.8 Mpa, and the compression ratio of the gas booster pump is 5:1;

[0026] In step S4, the adjustment range of the indication value of the second driving gas pressure gauge is 0.1 - 0.8 Mpa, the compression ratio of the gas-liquid booster pump is 100:1, and the adjustment range of the indication value of the second high-pressure pressure gauge is 10 - 80 Mpa.

[0027] The beneficial effects of the present invention are:

[0028] In the present invention, ammonia gas is first boosted to more than 1 Mpa by the gas booster pump, so that ammonia gas is transformed from a gaseous state to a liquid state to form liquid ammonia, and then the liquid ammonia is boosted to the target injection pressure by the gas-liquid booster pump, and the boosting of ammonia gas is completed through two-stage boosting.

[0029] In the present invention, both the gas booster pump and the gas-liquid booster pump are gas-driven booster pumps, and the driving gas is provided by the air compressor. Compared with the electric-driven booster pump, since ammonia gas and liquid ammonia are both flammable, no electric arc and spark are generated during the boosting process, avoiding fire.

[0030] In the present invention, a gas-liquid separator is provided. After the ammonia gas is pressurized by the gas booster pump, bubbles may be generated, resulting in residual ammonia gas. The gas-liquid separator is used to separate the residual ammonia gas in the liquid ammonia pressurized by the gas booster pump and discharge it to the gas booster pump for re-pressurization. On the one hand, it avoids the influence of the bubbles mixed in the liquid ammonia on the pressurization effect. On the other hand, it reduces the waste of ammonia gas.

[0031] In the present invention, a cooling box is provided inside the gas booster pump. Since the internal energy of the ammonia gas increases after being compressed by the gas booster pump, the temperature of the output liquid ammonia increases, resulting in an increase in the saturated vapor pressure. When the saturated vapor pressure of the liquid ammonia is greater than the pressure of the liquid ammonia, it is easy to vaporize into ammonia gas. Therefore, the liquid ammonia is cooled through the cooling box to reduce its saturated vapor pressure again and reduce the loss of liquid ammonia.

[0032] Before the experiment in the present invention, a vacuum pump is used to extract the residual gas in the pipeline to achieve a vacuum state in the pipeline and avoid the influence of the residual gas in the pipeline on the experiment.

[0033] In the present invention, the ammonia / ammonia gas in the constant volume bomb, the gas-liquid booster pump, the gas booster pump, and the high-pressure common rail is discharged into the exhaust storage through the exhaust unloading system to complete the pressure relief of the system. If the ammonia / ammonia gas is not discharged in time after the experiment, on the one hand, it is easy to leak under abnormal conditions, bringing potential safety hazards. On the other hand, the pipeline and the device are in a high-pressure environment for a long time, and both ammonia / ammonia gas are corrosive, which is easy to cause wear and corrosion to the pipeline and the device and bring safety risks. [[ID=\\(11\\)]]Description of the Drawings

[0034] Figure 1 It is a schematic diagram of the liquid ammonia high-pressure injection experiment system in the present invention.

[0035] Figure 2 It is a schematic diagram of the gas booster pump and the first housing in the present invention.

[0036] Figure 3 It is a schematic diagram of the gas-liquid booster pump and the second housing in the present invention.

[0037] In the figure, 1. Ammonia explosion-proof cabinet; 2. Ammonia storage; 3. Air compressor; 4. First housing; 5. Gas booster pump; 6. Gas-liquid separator; 7. Gas-liquid booster pump; 8. Second housing; 9. Exhaust storage; 10. Vacuum pump; 11. Constant volume bomb; 12. Common rail pipe; 14. Second high-pressure needle valve; 15. Third high-pressure needle valve; 16. ECU electronic control unit; 17. Nozzle; 18. Host computer; 19. Heater; 20. Gas storage tank; 21. Constant volume bomb temperature and pressure control operation console; 22. Third high-pressure pressure gauge; 24. Cooling box; 25. Coiled pipe; 27. Exhaust valve; 28. First driving gas pressure regulating valve; 29. High-pressure outlet valve; 30. First unloading valve; 31. First driving gas pressure gauge; 32. First driving gas switch; 33. First high-pressure pressure gauge; 34. Second driving gas pressure regulating valve; 35. Medium inlet switch; 36. Fourth high-pressure needle valve; 37. Second unloading valve; 38. Second driving gas pressure gauge; 39. Second driving gas switch; 40. Second high-pressure pressure gauge. Specific embodiments

[0038] The following further elaborates on the present invention in detail in conjunction with the specific embodiments of the accompanying drawings, but the protection scope of the present invention is not limited thereto.

[0039] As Figure 1As shown, the liquid ammonia high-pressure injection experimental system includes an ammonia storage 2, a gas booster pump 5, a gas-liquid booster pump 7, an air compressor 3, a common rail pipe 12, a nozzle 17, an ECU electronic control unit 16, a host computer 18, a constant volume bomb 11, a constant volume bomb 11 temperature and pressure operating table and an exhaust storage 9. The ammonia storage 2, the gas booster pump 5, the gas-liquid booster pump 7, the common rail pipe 12 and the nozzle 17 are connected in sequence through pipelines. The gas booster pump 5 and the gas-liquid booster pump 7 are both gas-driven booster pumps. Compared with electric-driven booster pumps, since both ammonia gas and liquid ammonia are flammable, no arc or spark is generated during the pressurization process, thereby avoiding fire. First, the ammonia gas is pressurized to above 1 MPa by the gas booster pump 5, so that the ammonia gas is converted from gas to liquid to form liquid ammonia, and then the liquid ammonia is pressurized to the target injection pressure by the gas-liquid booster pump 7, and the ammonia gas is pressurized through two-stage supercharging; the common rail pipe 12 acts as a pressure accumulator. On the one hand, it can realize the intermittent injection of liquid ammonia, and on the other hand, it avoids the instability of the liquid ammonia amount during the ammonia pressurization process, which affects the stability of the injection, thereby achieving stable injection; a third high-pressure pressure gauge 22 is provided on the common rail pipe 12 for detecting the liquid ammonia pressure in the common rail pipe 12. The ammonia storage device 2 is arranged in the ammonia explosion-proof cabinet 1 to prevent ammonia explosion accidents; the air compressor 3 is connected to the gas booster pump 5 and the gas-liquid booster pump 7 through a pipeline for providing driving gas to the gas booster pump 5 and the gas-liquid booster pump 7. A gas-liquid separator 6 is provided between the gas booster pump 5 and the gas-liquid booster pump 7. Three interfaces are provided on the gas-liquid separator 6, namely: the inlet of the gas-liquid separator 6 is connected to the outlet of the gas booster pump 5, the air outlet at the top of the gas-liquid separator 6 is connected to the inlet of the gas booster pump 5, and the liquid outlet of the gas-liquid separator 6 is connected to the inlet of the gas-liquid booster pump 7. After the ammonia is pressurized by the gas booster pump 5, bubbles may be generated, thereby generating residual ammonia. The gas-liquid separator 6 is used to separate the residual ammonia in the liquid ammonia pressurized by the gas booster pump 5 and discharge it to the gas booster pump 5 for re-pressurization. On the one hand, it avoids the bubbles mixed in the liquid ammonia from affecting the pressurization effect, and on the other hand, it reduces To avoid the waste of ammonia, the gas-liquid separator 6 adopts a vertical gravity gas-liquid separator to settle the liquid ammonia, and the residual ammonia will be discharged from the upper exhaust port by buoyancy, and the discharged trace ammonia will re-enter the gas booster pump 5 through the upper reflux pipe for pressurization, avoiding the waste of gas and direct discharge to the outside to cause harm to the body; the pipe connected to the outlet of the gas booster pump 5 is a coil 25, and the coil 25 is located in the cooling box 24. The cooling box 24 is filled with a coolant for heat exchange, which is used to cool the liquid ammonia pressurized by the gas booster pump 5. Because the internal energy of ammonia increases after being compressed by the gas booster pump 5, the temperature of the output liquid ammonia increases, thereby increasing the saturated vapor pressure. When the saturated vapor pressure of liquid ammonia is greater than the pressure of liquid ammonia, it is easy to vaporize into ammonia. Therefore, the liquid ammonia is cooled by the cooling box to reduce its saturated vapor pressure again, reducing the loss of liquid ammonia.A vacuum pump 10 is connected to the rear end of the gas-liquid booster pump 7 through a pipeline. The vacuum pump 10 and the common rail pipe 12 are arranged in parallel and are connected through a pipeline to extract the residual gas in the gas-liquid booster pump 7, the common rail pipe 12 and the pipeline therebetween to achieve a vacuum state and avoid the influence of the residual gas on the experimental results. A first high-pressure needle valve is arranged on the outlet pipeline of the vacuum pump 10 to control the on-off of the outlet pipeline of the vacuum pump 10.

[0040] The ECU electronic control unit 16 is electrically connected to the upper computer 18, the common rail pipe 12 and the nozzle 17. The target frequency and pulse width of the liquid ammonia injection are set on the upper computer 18. The third high-pressure needle valve 15 is opened. According to the target frequency and pulse width, the upper computer 18 controls the on-off of the common rail pipe 12 and the nozzle 17 through the ECU electronic control unit 16, and then injects into the constant volume bomb 11 at the target frequency and pulse width. A third high-pressure needle valve 15 is arranged on the pipeline between the common rail pipe 12 and the nozzle 17 to manually control the opening and closing of the injection. The nozzle 17 is fixed on the constant volume bomb 11. A temperature sensor and a pressure sensor are arranged on the constant volume bomb 11 to detect the temperature and air pressure of the constant volume bomb 11 respectively. The temperature sensor and the pressure sensor are electrically connected to the temperature and pressure operation table of the constant volume bomb 11, and the temperature and pressure operation table of the constant volume bomb 11 can display the temperature and air pressure values of the constant volume bomb 11; at least one gas storage tank 20 is connected to the constant volume bomb 11, and the gas storage tank 20 is electrically connected to the temperature and pressure operation table of the constant volume bomb 11 to provide nitrogen and / or air. In the present invention, two gas storage tanks 20 are connected to the constant volume bomb 11, which are respectively filled with nitrogen and air; a heater 19 is arranged on the constant volume bomb 11, and the heater 19 is electrically connected to the temperature and pressure operation table of the constant volume bomb 11 to control the opening degree of the temperature in the constant volume bomb 11; the exhaust memory 9 is connected to the gas booster pump 5, the gas-liquid booster pump 7, the common rail pipe 12 and the constant volume bomb 11 through a pipeline for exhaust unloading. In the present invention, the exhaust memory 9 adopts a sealed water tank that can dissolve ammonia gas / liquid ammonia; if the liquid ammonia / ammonia gas is not discharged in time after the test, on the one hand, it is easy to leak under abnormal conditions, bringing potential safety hazards. On the other hand, the pipeline and the device are in a high-pressure environment for a long time, and both liquid ammonia / ammonia gas are corrosive, which is easy to cause wear and corrosion to the pipeline and the device and bring safety risks. An exhaust valve 27 is arranged on the pipeline between the constant volume bomb 11 and the exhaust memory 9 to control the exhaust unloading of the constant volume bomb 11; a second high-pressure needle valve 14 is arranged on the pipeline between the common rail pipe 12 and the exhaust memory 9 to control the unloading of the common rail pipe 12.

[0041] Such as Figure 2As shown, a first housing 4 is provided outside the gas booster pump 5. A first driving gas pressure gauge 31, a first high-pressure pressure gauge 33, a first driving gas pressure regulating valve 28, a high-pressure outlet valve 29, a first unloading valve 30, and a first driving gas switch 32 are provided on the first housing 4. The first driving gas switch 32, the first driving gas pressure regulating valve 28, and the first driving gas pressure gauge 31 are arranged on the pipeline between the gas booster pump 5 and the air compressor 3. Among them, compared with the first driving gas switch 32 and the first driving gas pressure regulating valve 28, the first driving gas pressure gauge 31 is closer to the gas booster pump 5. The first driving gas pressure gauge 31 is used to detect the driving gas pressure of the gas booster pump 5. The first driving gas pressure regulating valve 28 is used to adjust the magnitude of the driving gas pressure of the gas booster pump 5. The first driving gas switch 32 is used to control the on-off of the pipeline between the gas booster pump 5 and the air compressor 3. The first high-pressure pressure gauge 33 and the high-pressure outlet valve 29 are arranged on the outlet pipeline of the gas booster pump 5. The first high-pressure pressure gauge 33 is used to detect the pressure of the liquid ammonia after being boosted by the gas booster pump 5. The high-pressure outlet valve 29 controls the on-off of the outlet pipeline of the gas booster pump 5. The first unloading valve 30 is arranged on the pipeline between the gas booster pump 5 and the exhaust storage 9 and is used for unloading control of the gas booster pump 5. Among them, the compression ratio of the gas booster pump 5 is 5:1, and the air compressor 3 with an adjustable pressure range of 0.1 - 0.8 MPa is used for driving. Therefore, the first driving gas pressure gauge 31 with an indicated value adjustment range of 0.1 - 0.8 Mpa is adopted. During the compression process, it is necessary to ensure that the indicated value of the first high-pressure pressure gauge 33 is not less than 1 MPa.

[0042] As Figure 3As shown in the figure, a second housing 8 is provided outside the gas-liquid booster pump 7. A second driving gas pressure gauge 38, a second high-pressure pressure gauge 40, a second driving gas pressure regulating valve 34, a medium inlet switch 35, a fourth high-pressure needle valve 36, a second unloading valve 37, and a second driving gas switch 39 are provided on the first housing 4. The second driving gas switch 39, the second driving gas pressure regulating valve 34, and the second driving gas pressure gauge 38 are arranged on the pipeline between the gas-liquid booster pump 7 and the air compressor 3. Among them, compared with the second driving gas switch 39 and the second driving gas pressure regulating valve 34, the second driving gas pressure gauge 38 is closer to the gas-liquid booster pump 7. The second driving gas switch 39 is used to control the on-off of the pipeline between the gas-liquid booster pump 7 and the air compressor 3. The second driving gas pressure regulating valve 34 adjusts the driving gas pressure of the gas-liquid booster pump 7. The second driving gas pressure gauge 38 is used to detect the driving gas pressure of the gas-liquid booster pump 7; the medium inlet switch 35 is arranged on the inlet pipeline of the gas-liquid booster pump 7 and is used to control the on-off of liquid ammonia entering the gas-liquid booster pump 7; the second high-pressure pressure gauge 40 and the fourth high-pressure needle valve 36 are arranged on the outlet pipeline of the gas-liquid booster pump 7. The second high-pressure pressure gauge 40 is used to detect the pressure of liquid ammonia after being boosted by the gas-liquid booster pump 7. The fourth high-pressure needle valve 36 is used to control the on-off of the outlet pipeline of the gas-liquid booster pump 7; the second unloading valve 37 is arranged on the pipeline between the gas-liquid booster pump 7 and the exhaust storage 9 and is used for unloading control of the gas-liquid booster pump 7; among them, the compression ratio of the gas-liquid booster pump 7 is 100:1, and the air compressor 3 with an adjustable pressure range of 0.1-0.8 MPa is used for driving. Therefore, the second driving gas pressure gauge 38 with an indication adjustment range of 0.1-0.8 Mpa is adopted, and the boosting range is 10-80 Mpa. Therefore, the second high-pressure pressure gauge 40 with an indication adjustment range of 10-80 Mpa is adopted.

[0043] The experimental method of the liquid ammonia high-pressure injection experimental system described in the present invention includes the following steps:

[0044] S1. Open the medium inlet switch 35 and the fourth high-pressure needle valve 36 to make the gas-liquid booster pump 7 and the common rail 12 in a connected state. Open the first high-pressure needle valve on the outlet pipeline of the vacuum pump 10, and start the vacuum pump 10 to extract the residual gas in the gas-liquid booster pump 7, the common rail 12 and the pipeline therebetween to achieve a vacuum state. Then close the vacuum pump 10, the first high-pressure needle valve, the medium inlet switch 35 and the fourth high-pressure needle valve 36;

[0045] S2. Open the ammonia gas cylinder, and at the same time open the high-pressure outlet valve 29, the gas-liquid separator 6, the medium inlet switch 35 and the fourth high-pressure needle valve 36. At this time, the first unloading valve 30 and the second unloading valve 37 remain in the closed state;

[0046] S3. Turn on the air compressor 3, open the first driving gas switch 32, and start the gas booster pump 5 to perform primary pressurization on ammonia gas to convert it into liquid ammonia. Adjust the first driving gas pressure regulating valve 28 to control the indication value of the first high-pressure pressure gauge 33 to be not less than 1 MPa; among them, the adjustable range of the indication value of the first driving gas pressure gauge 31 is 0.1 - 0.8 Mpa, and the compression ratio of the gas booster pump 5 is 5:1;

[0047] S4. Open the second driving gas switch 39, and start the gas-liquid booster pump 7 to further pressurize the liquid ammonia. Adjust the second driving gas pressure regulating valve 34 to control the indication value of the second high-pressure pressure gauge 40 to reach the target injection pressure; among them, the adjustable range of the indication value of the second driving gas pressure gauge 38 is 0.1 - 0.8 Mpa, the compression ratio of the gas-liquid booster pump 7 is 100:1, and the adjustable range of the indication value of the second high-pressure pressure gauge 40 is 10 - 80 Mpa;

[0048] S6. The temperature sensor and pressure sensor on the constant volume bomb 11 monitor the temperature and air pressure of the constant volume bomb 11, and adjust the temperature and air pressure inside the constant volume bomb 11 to the target values through the constant volume bomb temperature and pressure control operation console 21;

[0049] S6. Set the target frequency and pulse width of liquid ammonia injection on the upper computer 18, open the third high-pressure needle valve 15, and according to the target frequency and pulse width, the upper computer 18 controls the on / off of the common rail pipe 12 and the nozzle 17 through the ECU electronic control unit 16, and then injects it into the constant volume bomb 11 at the target frequency and pulse width;

[0050] S7. After the injection is completed, close the first driving gas switch 32 and the second driving gas switch 39; open the exhaust valve 27 to discharge the gas in the constant volume bomb 11 into the exhaust storage 9; close the ammonia gas cylinder and the air compressor 3. According to the principle of first high-pressure unloading and then low-pressure unloading, first open the second unloading valve 37 to discharge the residual liquid ammonia / ammonia gas in the gas-liquid booster pump 7 into the exhaust storage 9; then open the first unloading valve 30 to discharge the residual liquid ammonia / ammonia gas in the gas booster pump 5 into the exhaust storage 9; open the second high-pressure needle valve 14 to discharge the residual liquid ammonia / ammonia gas in the common rail pipe 12 into the exhaust storage 9, so as to realize the unloading and exhaust of the constant volume bomb 11, the gas-liquid booster pump 7, the gas booster pump 5, and the common rail pipe 12.

[0051] The above examples are the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Without departing from the essence of the present invention, any obvious improvements, substitutions or variations that those skilled in the art can make all belong to the protection scope of the present invention.

Claims

1. A high-pressure liquid ammonia injection experimental system, characterized in that: It includes an ammonia storage (2), a gas booster pump (5), a gas-liquid booster pump (7), an air compressor (3), a constant volume bomb (11), a common rail pipe (12), a nozzle (17), a constant volume bomb temperature and pressure operation console, an ECU electronic control unit (16) and a host computer (18). The ammonia storage (2), the gas booster pump (5), the gas-liquid booster pump (7), the common rail pipe (12), and the nozzle (17) are connected in sequence through pipelines. The air compressor (3) is connected to the gas booster pump (5) and the gas-liquid booster pump (7) through pipelines to provide driving gas for the gas booster pump (5) and the gas-liquid booster pump (7). A gas-liquid separator (6) is arranged between the gas booster pump (5) and the gas-liquid booster pump (7). The outlet of the gas booster pump (5) is communicated with the inlet of the gas-liquid separator (6), and the inlet of the gas-liquid booster pump (7) is communicated with the liquid outlet of the gas-liquid separator (6). The gas outlet at the top of the gas-liquid separator (6) is communicated with the inlet of the gas booster pump (5); The ECU electronic control unit (16) is electrically connected to the host computer (18), the common rail pipe (12), and the nozzle (17). The host computer (18) controls the on-off of the common rail pipe (12) and the nozzle (17) through the ECU electronic control unit (16). The nozzle (17) is fixed on the constant volume bomb (11). A temperature sensor and a pressure sensor electrically connected to the temperature and pressure operation console are arranged in the constant volume bomb (11) for detecting the temperature and air pressure of the constant volume bomb (11) respectively; A heater (19) is arranged on the constant volume bomb (11) and is communicated with at least one gas storage tank (20). The gas storage tank (20) and the heater (19) are both controlled by the constant volume bomb temperature and pressure operation console.

2. The liquid ammonia high-pressure injection experimental system according to claim 1, wherein The pipeline connected to the outlet of the gas booster pump (5) is a coiled pipe (25). The coiled pipe (25) is located in a cooling box (24), and the cooling box (24) is filled with a coolant for heat exchange.

3. The liquid ammonia high-pressure injection experiment system according to claim 1, characterized in that, It also includes an exhaust gas storage (9). Exhaust pipelines leading to the exhaust gas storage (9) are provided on the gas booster pump (5), the gas-liquid booster pump (7), the common rail pipe (12), and the constant volume bomb (11). First unloading valves (30), second unloading valves (37), second high-pressure needle valves (14), and exhaust valves (27) are respectively provided on the exhaust pipelines of the gas booster pump (5), the gas-liquid booster pump (7), the common rail pipe (12), and the constant volume bomb (11).

4. The liquid ammonia high-pressure injection experiment system according to claim 1, wherein It also includes a vacuum pump (10). The vacuum pump (10) is respectively communicated with the gas-liquid booster pump (7) and the common rail pipe (12). A first high-pressure needle valve is arranged on the outlet pipeline of the vacuum pump (10) for controlling the on-off of the outlet pipeline of the vacuum pump (10).

5. The liquid ammonia high-pressure injection experimental system according to claim 1, characterized in that, The ammonia storage (2) is arranged in an ammonia explosion-proof cabinet (1).

6. The liquid ammonia high-pressure injection experimental system according to claim 3, characterized in that, Two gas storage tanks (20) are connected to the constant volume bomb (11), which are respectively filled with nitrogen and air.

7. The liquid ammonia high-pressure injection experimental system according to claim 3, characterized in that, A first driving gas switch (32), a first driving gas pressure regulating valve (28) and a first driving gas pressure gauge (31) are arranged on the pipeline between the gas booster pump (5) and the air compressor (3), which are respectively used to control the on-off of the pipeline between the gas booster pump (5) and the air compressor (3), adjust the pressure of the driving gas of the gas booster pump (5) and detect the pressure of the driving gas of the gas booster pump (5); A first high-pressure pressure gauge (33) and a high-pressure outlet valve (29) are arranged on the outlet pipeline of the gas booster pump (5), which are respectively used to detect the pressure of liquid ammonia after being boosted by the gas booster pump (5) and control the on-off of the outlet pipeline of the gas booster pump (5); A second driving gas switch (39), a second driving gas pressure regulating valve (34) and a second driving gas pressure gauge (38) are arranged on the pipeline between the gas-liquid booster pump (7) and the air compressor (3), which are respectively used to control the on-off of the pipeline between the gas-liquid booster pump (7) and the air compressor (3), adjust the pressure of the driving gas of the gas-liquid booster pump (7) and detect the pressure of the driving gas of the gas-liquid booster pump (7); A medium inlet switch (35) is arranged on the inlet pipeline of the gas-liquid booster pump (7) to control the on-off of the liquid ammonia entering the gas-liquid booster pump (7); a second high-pressure pressure gauge (40) and a fourth high-pressure needle valve (36) are arranged on the outlet pipeline of the gas-liquid booster pump (7), which are respectively used to detect the pressure of liquid ammonia after being boosted by the gas-liquid booster pump (7) and control the on-off of the outlet pipeline of the gas-liquid booster pump (7); A third high-pressure pressure gauge (22) is arranged on the common rail pipe (12) to detect the pressure of liquid ammonia in the common rail pipe (12); a third high-pressure needle valve (15) is arranged on the pipeline between the common rail pipe (12) and the nozzle (17) to manually control the opening and closing of the injection; 8. The experimental method of the liquid ammonia high-pressure injection experimental system according to claim 1, characterized in that It includes the following steps: S1. Open the medium inlet switch (35) and the fourth high-pressure needle valve (36) to make the gas-liquid booster pump (7) and the common rail pipe (12) in a connected state. Open the first high-pressure needle valve on the outlet pipeline of the vacuum pump (10), and start the vacuum pump (10) to extract the residual gas in the gas-liquid booster pump (7), the common rail pipe (12) and the pipeline therebetween to achieve a vacuum state. Then close the vacuum pump (10), the first high-pressure needle valve, the medium inlet switch (35) and the fourth high-pressure needle valve (36); S2. Open the ammonia gas cylinder, and at the same time open the high-pressure outlet valve (29), the gas-liquid separator (6), the medium inlet switch (35) and the fourth high-pressure needle valve (36). At this time, the first unloading valve (30) and the second unloading valve (37) remain closed; S3. Open the air compressor (3), open the first driving gas switch (32), and start the gas booster pump (5) to perform primary pressurization on ammonia gas to convert it into liquid ammonia. Adjust the first driving gas pressure regulating valve (28) to control the indication value of the first high-pressure pressure gauge (33) to be not less than 1 MPa; S4. Open the second driving gas switch (39), and start the gas-liquid booster pump (7) to further pressurize the liquid ammonia. Adjust the second driving gas pressure regulating valve (34) to control the indication value of the second high-pressure pressure gauge (40) to reach the target injection pressure; S5. The temperature sensor and pressure sensor on the constant volume bomb (11) monitor the temperature and air pressure of the constant volume bomb (11), and the temperature and air pressure in the constant volume bomb (11) are adjusted to the target values through the constant volume bomb temperature and pressure control console (21); S6. Set the target frequency and pulse width of the liquid ammonia injection on the upper computer (18), open the third high-pressure needle valve (15), and according to the target frequency and pulse width, the upper computer (18) controls the on-off of the common rail pipe (12) and the nozzle (17) through the ECU electronic control unit (16), and then injects it into the constant volume bomb (11) at the target frequency and pulse width; S7. After the injection is completed, close the first driving gas switch (32) and the second driving gas switch (39); open the exhaust valve (27) to discharge the gas in the constant volume bomb (11) into the exhaust storage (9); close the ammonia gas cylinder and the air compressor (3), and according to the principle of first high-pressure unloading and then low-pressure unloading, first open the second unloading valve (37) to discharge the residual liquid ammonia / ammonia gas in the gas-liquid booster pump (7) into the exhaust storage (9); then open the first unloading valve (30) to discharge the residual liquid ammonia / ammonia gas in the gas booster pump (5) into the exhaust storage (9); open the second high-pressure needle valve (14) to discharge the residual liquid ammonia / ammonia gas in the common rail pipe (12) into the exhaust storage (9), so as to realize the unloading and exhaust of the constant volume bomb (11), the gas-liquid booster pump (7), the gas booster pump (5), and the common rail pipe (12).

9. The experimental method according to claim 8, characterized in that: In step S3, the indication adjustment range of the first driving gas pressure gauge (31) is 0.1 - 0.8 Mpa, and the compression ratio of the gas booster pump (5) is 5:1; In step S4, the indication adjustment range of the second driving gas pressure gauge (38) is 0.1 - 0.8 Mpa, the compression ratio of the gas-liquid booster pump (7) is 100:1, and the indication adjustment range of the second high-pressure pressure gauge (40) is 10 - 80 Mpa.

Images