Test platform and method of boil-off gas treatment and utilization integrated system

Abstract

The invention relates to a test platform and method for a boil-off gas treatment and utilization integrated system, and the test platform comprises an LNG supply system, a natural gas supply subsystem, a boil-off gas treatment and utilization system equipment group, a gas consumption user simulation system, and a control hardware system. According to the testing method, the gas supply flow is changed by adjusting the valve opening degree of a control valve on a host and a generator simulation pipeline, system gas supply stability testing under different loads is carried out, and testing comprises the three parts of compressor gas supply testing, forced evaporation gas and LD heater gas supply testing and compressor and forced evaporator combined gas supply testing. The test platform provided by the invention can provide a technical verification platform and low-temperature verification service for integrated innovation of an autonomous boil-off gas treatment and utilization system in China, and has very important significance for realizing engineering application of domestic low-temperature equipment in China.

Description

Technical Field

[0001] This application relates to the technical field of shipbuilding, and particularly to a test platform and method for an integrated system for evaporation gas treatment and utilization. Background Art

[0002] Natural gas is a recognized clean fossil energy source, with characteristics such as safety, high efficiency, economy, and environmental friendliness, and will maintain a long-term growth trend. According to the statistical data of the Chinese customs, the total annual import volume of LNG in China reached 78.93 million tons in 2021, and China has surpassed Japan to become the world's largest importer of liquefied natural gas (LNG). However, the market share of China's LNG ships and related industrial chain equipment is relatively low, especially there are obvious shortcomings in the core systems of the industrial chain and the supporting of their material equipment. At present, China is significantly at a disadvantage in terms of onshore LNG cryogenic engineering test capabilities, lacking an onshore LNG cryogenic test center. There is a lack of functional verification and performance test platforms and related technical standards for relevant systems and various domestic equipment. There are only a small number of onshore LNG production, storage, and transportation technology principle verification and static test facilities in China, and an independent cryogenic test verification system has not been established, which cannot meet the cryogenic test verification requirements such as comprehensive performance and reliability during the development of domestic systems and equipment, seriously restricting the engineering development and shipboard application of LNG industrial chain equipment.

[0003] For the current in-depth development of the industry and technological innovation, it is urgent to carry out the construction of an LNG cryogenic test engineering test verification system. The development and verification of systems and equipment in the LNG industrial chain can complete tests onshore, complete relevant environmental verification with scaled-down components as the carrier, or complete typical operating environment verification with system prototypes as the carrier. The test platform for the evaporation gas treatment and utilization system is an important part of the construction of the LNG cryogenic test engineering test verification system, and in the future, it can provide a technical verification platform and cryogenic verification services for the integrated innovation of China's independent evaporation gas treatment and utilization system, which is of great significance for realizing the engineering application of domestic cryogenic equipment in China. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] This application provides a test platform and method for an integrated system for evaporation gas treatment and utilization to solve the problems in the above background art.

[0006] (2) Technical Solutions

[0007] In a first aspect, this application provides a test platform for an integrated system for evaporation gas treatment and utilization, and the test platform includes an LNG supply system, a natural gas supply subsystem, an evaporation gas treatment and utilization system equipment group, a gas-consuming user simulation system, and a control hardware system;

[0008] The LNG supply system includes an LNG storage tank, a first cryogenic gas pump, a second cryogenic gas pump, a first pipe group, and a first valve group;

[0009] The natural gas supply subsystem includes a cryogenic natural gas tank, a natural gas cooler, a second pipe group, and a second valve group;

[0010] The boil-off gas treatment and utilization system equipment group includes a compressor, a forced evaporator, a gas-liquid separator, an LD heater, a buffer tank, an LNG air-cooled heater, a water-bath vaporizer, a reflux air-cooled heater, a boil-off gas re-liquefaction device, a third pipe group, and a third valve group;

[0011] The gas-consuming user simulation system includes a high-pressure normal-temperature natural gas storage tank, a fourth pipe group, and a fourth valve group;

[0012] The control hardware system includes all the temperature sensors, pressure sensors, flow meters, flow sensors, and integrated control modules in the test platform.

[0013] Further, the first pipe group includes an LNG supply main pipe, a first LNG supply branch pipe, a second LNG supply branch pipe, a first LNG supply return pipe, a second LNG supply return pipe, and an LNG supply return main pipe; the first valve group includes all the control valves, check valves, and isolation valves on the first pipe group;

[0014] The first cryogenic gas pump is connected to the first LNG supply branch pipe, and the second cryogenic gas pump is connected to the second LNG supply branch pipe; the first LNG supply branch pipe and the second LNG supply branch pipe are in parallel and are both connected to the LNG supply main pipe;

[0015] The first LNG supply return pipe is connected to the first LNG supply branch pipe, and the second LNG supply return pipe is connected to the second LNG supply branch pipe; the first LNG supply return pipe and the second LNG supply return pipe are in parallel and are both connected to the LNG supply return main pipe; the LNG supply return main pipe is connected to the LNG storage tank.

[0016] Further, the number of the cryogenic natural gas tanks is three, and the liquefied natural gas first passes through the first cryogenic natural gas tank and then enters the second cryogenic natural gas tank or the third cryogenic natural gas tank;

[0017] The second pipe group includes a first NG supply main pipe before the first low-temperature natural gas tank, a second NG supply main pipe after the first low-temperature natural gas tank, a first NG supply branch pipe before the second low-temperature natural gas tank, a second NG supply branch pipe after the second low-temperature natural gas tank, a third NG supply branch pipe before the third low-temperature natural gas tank, a fourth NG supply branch pipe after the third low-temperature natural gas tank, a first NG connection bypass pipe between the second low-temperature natural gas tank and the third low-temperature natural gas tank, and a fifth NG supply branch pipe between the natural gas cooler and the first low-temperature natural gas tank; the second valve group includes all control valves, isolation valves, and check valves on the second pipe group.

[0018] The first NG supply branch pipe is in parallel with the third NG supply branch pipe, and the second NG supply branch pipe is in parallel with the fourth NG supply branch pipe. The first NG supply branch pipe and the third NG supply branch pipe are jointly connected to the second NG supply main pipe.

[0019] Further, the third pipe group includes the sixth to sixteenth NG supply branch pipes, a heavy component reflux pipe, a main engine gas supply main pipe, and a steam reflux pipe; the third valve group includes all control valves, isolation valves, and check valves on the third pipe group.

[0020] Further, the LNG supply main pipe is connected to an LNG air temperature heater. The LNG air temperature heater is connected to a water bath vaporizer through the sixth NG supply branch pipe. The outlet of the water bath vaporizer is connected to the first NG supply main pipe. The second NG supply branch pipe and the fourth NG supply branch pipe are jointly connected to the seventh NG supply branch pipe. The inlet of the compressor is connected to the seventh NG supply branch pipe, and the outlet of the compressor is connected to the eighth NG supply branch pipe;

[0021] The outlet of the forced evaporator is connected to the inlet of the gas-liquid separator through the ninth and tenth NG supply branch pipes. The steam at the outlet of the forced evaporator can also return to the LNG storage tank through the ninth supply branch pipe and the steam reflux pipe;

[0022] The outlet of the gas-liquid separator is connected to the inlet of the LD heater through the eleventh NG supply branch pipe. The outlet of the LD heater is connected to the twelfth NG supply branch pipe. The eighth NG supply branch pipe and the twelfth NG supply branch pipe are jointly connected to the main engine gas supply main pipe. The sixteenth NG supply branch pipe is also connected to the main engine gas supply main pipe. The sixteenth NG supply branch pipe is connected to the buffer tank. The heavy components separated by the gas-liquid separator are connected to the inlet of the reflux air temperature heater through the heavy component reflux pipe. The outlet of the reflux air temperature heater is connected to the low-temperature natural gas tank through the fifteenth NG supply branch pipe;

[0023] The inlet of the evaporative gas re-liquefaction device is connected to the thirteenth NG supply branch pipe; the outlet of the evaporative gas re-liquefaction device is connected to the LNG storage tank through the fourteenth NG supply branch pipe.

[0024] Further, the fourth pipe group includes a main host simulation pipe, a main generator simulation pipe, a seventeenth NG supply branch pipe, and an eighteenth NG supply branch pipe; the fourth valve group includes all control valves, isolation valves, check valves, and emergency cut-off valves on the fourth pipe group;

[0025] The main host simulation pipe and the main generator simulation pipe are in parallel and are both connected to the main host gas supply pipe and the seventeenth NG supply branch pipe; the high-pressure normal-temperature natural gas storage tank and the natural gas cooler are connected through the eighteenth NG supply branch pipe; the inlet of the high-pressure normal-temperature natural gas storage tank is connected to the main host simulation pipe and the main generator simulation pipe; the thirteenth NG supply branch pipe is connected to the main host simulation pipe.

[0026] Further, all temperature sensors, pressure sensors, flow meters, and flow sensors in the control hardware system are connected to the integrated control module, which is used to receive the data transmitted by the sensors and make corresponding feedback. If the data such as pipeline pressure and flow rate exceeds the set value during the test, the integrated control module can give an alarm and urgently control the opening of the corresponding valves for feedback adjustment.

[0027] In a second aspect, the present application provides a test method for an evaporation gas treatment and utilization integrated system, which is implemented based on the above test platform; the test method includes:

[0028] Check all integrated system test devices and blow wash the entire pipeline system;

[0029] Adjust the valve opening of the control valves on the main host and generator simulation pipelines to change the gas supply flow rate, and conduct system gas supply stability tests under different loads. The tests include compressor gas supply tests, forced evaporation gas plus LD heater gas supply tests, and combined gas supply tests of the compressor and the forced evaporator;

[0030] After the test is completed, perform operations such as heating up, inerting, and purging the pipeline.

[0031] Further, the checking all integrated system test devices and blow washing the entire pipeline system includes:

[0032] Check the connection of each device in the entire test system, check whether there is leakage at each pipeline connection, detect the airtightness of the pipeline system, and check whether the control hardware system is working properly;

[0033] Inject inert gas into the pipeline system to blow wash its pipeline to make it in an inert state. After the entire pipeline system is in an inert state, perform a precooling operation on the test system.

[0034] Further, the operations of heating up, inerting, and purging the pipeline after the test is completed include:

[0035] After the operation is completed, the LNG vapor heated by the pipeline heating system is used to evaporate the LNG in the test system pipeline and raise the temperature of the pipeline system.

[0036] An inert gas is introduced to inertize the test system, and finally dry air is used to displace the inert gas, so that the test system is maintained at the normal temperature working pressure and temperature.

[0037] (3) Beneficial effects

[0038] The above technical solutions of this application have the following advantages:

[0039] The test platform of the boil-off gas treatment and utilization integrated system provided in the first aspect of this application can provide a technical verification platform and cryogenic verification service for the integrated innovation of the domestic boil-off gas treatment and utilization system in China, which is of great significance for realizing the engineering application of domestic cryogenic equipment in China.

[0040] It can be understood that the beneficial effects of the second aspect can refer to the relevant descriptions in the first aspect above, and will not be elaborated here. Description of the drawings

[0041] In order to more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0042] Figure 1 It is a schematic diagram of the test platform of the boil-off gas treatment and utilization integrated system provided by this application.

[0043] Reference Numerals: 1-2, low-temperature gas pump; 3, LNG storage tank; 4, LNG air-cooled heater; 5, water-bath vaporizer; 6-8, low-temperature natural gas tanks; 9, compressor; 10, buffer tank; 11, high-pressure normal-temperature natural gas storage tank; 12, natural gas cooler; 13, boil-off gas re-liquefaction unit; 14, forced vaporizer; 15, gas-liquid separator; 16, LD heater; 17, reflux air-cooled heater; 18, control module; 19, main engine analog flow control valve; 20, generator analog flow control valve; 21, first flow sensor; 22, first flowmeter; 23, second flow sensor; 24, second flowmeter; 25, first emergency cut-off valve; 26, second emergency cut-off valve; 27, compressor control valve; 28, forced vaporizer flow control valve; 29, first gas pump outlet flow control valve; 30, second gas pump outlet flow control valve; 31, fourth pressure sensor; 34-39, first pipe group; 40-47, second pipe group; 48-61, third pipe group; 62-65, fourth pipe group; 66-68, first to third pressure sensors. Detailed Embodiments

[0044] The following describes in further detail the specific embodiments of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0047] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0048] The following will further describe in detail the specific implementation manners of this application in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate this application, but are not used to limit the scope of this application.

[0049] An embodiment of this application provides a test platform for an evaporation gas treatment and utilization integrated system, as Figure 1 shown. The test platform includes an LNG supply system, a natural gas supply subsystem, an evaporation gas treatment and utilization system equipment group, a gas-consuming user simulation system, and a control hardware system.

[0050] The LNG supply system includes an LNG storage tank 3, a cryogenic gas pump 1-2, a first pipe group, and a first valve group, and is used to transport the LNG in the storage tank to the natural gas supply subsystem or the forced vaporizer 14 through the cryogenic pump during testing; the natural gas supply subsystem includes cryogenic natural gas tanks 6-8, a natural gas cooler 12, a second pipe group, and a second valve group, and is used to store and transport natural gas for testing; the evaporation gas treatment and utilization system equipment group includes a compressor 9, a forced evaporator 14, a gas-liquid separator 15, an LD heater 16, a buffer tank 10, an LNG air-temperature heater 4, a water-bath vaporizer 5, a reflux air-temperature heater 17, an evaporation gas re-liquefaction device 13, a third pipe group, and a third valve group; the gas-consuming user simulation system includes a high-pressure normal-temperature natural gas storage tank 11, a fourth pipe group, and a fourth valve group; the control hardware system includes all temperature sensors, pressure sensors, flow meters, flow sensors, and an integrated control module 18 in the entire integrated test system.

[0051] Specifically, as Figure 1 shown, the first pipe group in the LNG supply system includes an LNG supply main pipe 36, a first LNG supply branch pipe 34, a second LNG supply branch pipe 35, a first LNG supply return pipe 37, a second LNG supply return pipe 38, and an LNG supply return main pipe 39; the first valve group includes all control valves, check valves, and isolation valves on the first pipe group.

[0052] The low-temperature gas pump 1 is connected to the first LNG supply branch pipe 34 at the rear, and the low-temperature gas pump 2 is connected to the second LNG supply branch pipe 35 at the rear; the first LNG supply branch pipe 34 and the second LNG supply branch pipe 35 are in parallel and are both connected to the LNG supply main pipe 36; the first LNG supply branch pipe 34 is connected to the first LNG supply return pipe 37, and the second LNG supply branch pipe 35 is connected to the second LNG supply return pipe 38. The first LNG supply return pipe 37 and the second LNG supply return pipe 38 are in parallel and are both connected to the LNG supply return main pipe 39; the LNG supply return main pipe 39 is connected to the LNG storage tank 3.

[0053] There are three low-temperature natural gas tanks 6-8 in the natural gas supply subsystem. The vaporized natural gas first passes through the low-temperature natural gas tank 6 and then enters the low-temperature natural gas tank 7 or the low-temperature natural gas tank 8; the second pipe group includes the first NG supply main pipe 40 before the NG tank 6, the second NG supply main pipe 41 after the NG tank 6, the first NG supply branch pipe 42 before the NG tank 7, the second NG supply branch pipe 44 after the NG tank 7, the third NG supply branch pipe 43 before the NG tank 8, the fourth NG supply branch pipe 45 after the NG tank 8, the first NG connection bypass pipe 47 between the NG tanks 7 and 8, and the fifth NG supply branch pipe 46 between the natural gas cooler 12 and the low-temperature natural gas tank 6; the second valve group includes all control valves, isolation valves, and check valves on the second pipe group.

[0054] The first NG supply branch pipe 42 and the third NG supply branch pipe 43 are in parallel, and the second NG supply branch pipe 44 and the fourth NG supply branch pipe 45 are in parallel. The first NG supply branch pipe 42 and the third NG supply branch pipe 43 are jointly connected to the second NG supply main pipe 41.

[0055] The third pipe group of the evaporation gas treatment and utilization system equipment group includes the sixth to sixteenth NG supply branch pipes, the heavy component return pipe 59, the main engine gas supply main pipe 60, and the steam return pipe 61. The third valve group includes all control valves, isolation valves, and check valves on the third pipe group.

[0056] The LNG supply main pipe 36 is connected to the LNG air temperature heater 4. The LNG air temperature heater 4 is connected to the water bath vaporizer 5 through the sixth NG supply branch pipe 48. The outlet of the water bath vaporizer 5 is connected to the first NG supply main pipe 40. The second NG supply branch pipe 44 and the fourth NG supply branch pipe 45 are jointly connected to the seventh NG supply branch pipe 49. The inlet of the compressor 9 is connected to the seventh NG supply branch pipe 49, and the outlet of the compressor 9 is connected to the eighth NG supply branch pipe 50. The outlet of the forced vaporizer 14 and the inlet of the gas-liquid separator 15 are connected through the ninth and tenth NG supply branch pipes 51-52. The steam at the outlet of the forced vaporizer can also return to the LNG storage tank 3 through the ninth supply branch pipe 51 and the steam return pipe 61. The outlet of the gas-liquid separator 15 and the inlet of the LD heater 16 are connected through the eleventh NG supply branch pipe 53. The outlet of the LD heater 16 is connected to the twelfth NG supply branch pipe 54. The eighth NG supply branch pipe 50 and the twelfth NG supply branch pipe 54 are jointly connected to the main engine gas supply main pipe 60. The sixteenth NG supply branch pipe 58 is also connected to the main engine gas supply main pipe 60. The sixteenth NG supply branch pipe 58 is connected to the buffer tank 10. The heavy components separated by the gas-liquid separator 15 are connected to the inlet of the reflux air temperature heater 17 through the heavy component return pipe 59. The outlet of the reflux air temperature heater 17 is connected to the low-temperature natural gas tank 6 through the fifteenth NG supply branch pipe 57. The inlet of the boil-off gas re-liquefaction device 13 is connected to the thirteenth NG supply branch pipe 55. The outlet of the boil-off gas re-liquefaction device 13 is connected to the LNG storage tank 3 through the fourteenth NG supply branch pipe 56.

[0057] The fourth pipe group of the gas-consuming user simulation system includes the main engine simulation main pipe 62, the generator simulation main pipe 63, the seventeenth NG supply branch pipe 64, and the eighteenth NG supply branch pipe 65. The fourth valve group includes all control valves, isolation valves, check valves, and emergency cut-off valves on the fourth pipe group.

[0058] The main engine simulation main pipe 62 and the generator simulation main pipe 63 are in parallel and are both connected to the main engine gas supply main pipe 60 and the seventeenth NG supply branch pipe 64. The high-pressure normal-temperature natural gas storage tank 11 and the natural gas cooler 12 are connected through the eighteenth NG supply branch pipe 65. The inlet of the high-pressure normal-temperature natural gas storage tank 11 is connected to the main engine simulation main pipe 62 and the generator simulation main pipe 63. The thirteenth NG supply branch pipe 55 is connected to the main engine simulation main pipe 62.

[0059] All temperature sensors, pressure sensors, flow meters, and flow sensors in the control hardware system are connected to the integrated control module 18. The control module 18 can receive the data transmitted by the sensors and make corresponding feedback. If the data such as pipeline pressure and flow rate during the test exceed the set value, the integrated control module 18 can give an alarm and urgently control the opening of the corresponding valves for feedback adjustment to avoid safety problems in the system due to excessive test pressure or flow rate.

[0060] In the equipment group of the evaporation gas treatment and utilization system, a pressure sensor 31 and a temperature sensor are installed on the buffer tank. While monitoring the gas state in the gas buffer tank, they also provide control signals for the frequency conversion control of the compressor 9 and the heating load of the gas heater 14.

[0061] Specifically, a first pressure sensor 66 is installed on the LNG storage tank 3 to monitor the pressure of the storage tank 3 in real time; a second pressure sensor 67 and a third pressure sensor 68 can monitor the pressure at the outlet of the gas pump and feed the pressure data back to the control module 18. The control module 18 can adjust the outlet flow of the gas pump through the first gas pump outlet flow control valve 29 and the second gas pump outlet flow control valve 30; a first flowmeter 22 and a second flowmeter 24 can respectively collect the flows of the main engine simulation pipeline 62 and the generator simulation pipeline 63 and feed them back to the first flow sensor 21 and the second flow sensor 23. The control module 18 can receive the flow data of the first and second flow sensors, and then simulate different load conditions of the main engine and generator pipelines by controlling the valve openings of the main engine simulation flow control valve 19 and the generator simulation flow control valve 20; there is a control valve 27 in front of the compressor 9 and a control valve 28 in front of the forced vaporizer 14. During the test process, the control module 18 can adjust the valve openings of the control valves 27-28 in real time according to the pressure value fed back by the fourth pressure sensor 31 behind the buffer tank to adjust the flow and pressure of the test system.

[0062] Other pressure sensors, temperature sensors, flowmeters and flow sensors in the integrated test system are used to monitor the pressure, temperature and flow at the inlets and outlets of the corresponding system equipment in real time and feed them back to the control module 18 in real time. The control module can adjust the control valve opening in real time according to the actual situation to ensure the stable and smooth operation of the system gas supply.

[0063] The control module can also receive external command signals and control the emergency cut-off valves 25-26 for emergency cut-off in case of emergency.

[0064] Specifically, the evaporation gas treatment and utilization integrated system test platform includes three gas supply modes: compressor gas supply, forced evaporation gas plus LD heater gas supply, and combined gas supply of compressor and forced evaporator.

[0065] In the compressor gas supply mode, the LNG in the LNG storage tank 3 is pressurized by the cryogenic gas pump 1 and then transported to the LNG air-cooled heater 4 for heating and gasification. The gasified liquid natural gas is further heated and gasified by the water bath vaporizer 5. At the same time, the pressure control valve after the water bath vaporizer reduces the pressure and then transports it to the cryogenic natural gas tank 6. Then, it is further depressurized to the inlet pressure required by the compressor 9 through the cryogenic natural gas tank 7 or the cryogenic natural gas tank 8. Then, it is boosted in pressure and temperature by the compressor 9. After reaching the temperature and pressure required at the inlet of the main engine or generator simulation system, it enters the buffer tank 10 for pressure stabilization. The natural gas after pressure stabilization enters the main engine simulation pipeline 62 or the generator simulation pipeline 63;

[0066] In the forced evaporation gas plus LD heater gas supply mode, the LNG in the LNG storage tank 3 is pressurized by the cryogenic gas pump 2 and then transported to the forced vaporizer 14 for heating and gasification. The gasified natural gas is separated by the gas-liquid separator 15 and then enters the LD heater 16 for further heating to reach the main engine gas temperature. Then, it enters the main engine simulation pipeline 62 or the generator simulation pipeline 63 after being pressure-stabilized by the gas buffer tank 10;

[0067] When the amount of evaporated natural gas (i.e., BOG) in the compressor gas supply mode is less than the demand of the main engine, the compressor and forced evaporator combined gas supply mode is adopted, that is, the above two gas supply modes are carried out simultaneously.

[0068] The natural gas at the outlets of the main engine and generator simulation pipelines 62 - 63 can flow back to the LNG storage tank 3 through the evaporation gas re-liquefaction device 13, or can enter the high-pressure normal temperature natural gas storage tank 11 and then flow back to the cryogenic natural gas tank 6 through the natural gas cooler 12. The heavy components flowing back from the gas-liquid separator 15 can be heated and gasified by the reflux air-cooled heater 17 and then return to the cryogenic natural gas tank 6. The high-pressure natural gas at the outlet of the forced vaporizer 14 can flow back to the LNG storage tank 3 when the pressure of the LNG storage tank 3 decreases to realize tank pressure boosting.

[0069] The embodiment of the present application also provides a test method for an evaporation gas treatment and utilization integrated system, which is realized based on the above test platform; the test method includes:

[0070] S1, check all the integrated system test devices and blow and wash the entire pipeline system.

[0071] Specifically, first, check the connection of each device in the entire test system; introduce dry air with stable operation for each item to dry the entire pipeline gas supply system; introduce heat source media with stable operation for each item to check for leaks in the heat source system of all heat exchange devices (including vaporizers and heaters) in the test system, and observe the leakage at each pipeline connection point; let inert gas (gaseous nitrogen) enter the entire test system to check the airtightness of each pipeline connection point in the test system; check whether the pipeline control hardware system works normally;

[0072] Then, an inert gas is introduced into the entire pipeline system to purge its pipeline and make it in an inert state; after the entire pipeline system is in an inert state, the inert gas in the pipeline is replaced with LNG vapor and introduced into the test system to reduce the CO2 and water vapor content in the system pipeline and avoid icing during subsequent cooling; after inerting with N2 and purging with LNG vapor, LNG is introduced into the liquid cargo pipeline in the system for precooling until the pipeline temperature drops to -130 °C and below.

[0073] S2. Conduct full-process tests on the integrated system for boil-off gas treatment and utilization.

[0074] Specifically, the test includes three parts: compressor air supply test, forced boil-off gas plus LD heater air supply test, and combined air supply test of the compressor and forced evaporator. During different air supply tests, by adjusting the main engine and generator to simulate the valve opening of the control valve on the pipeline to change the air supply flow rate, the air supply stability of the system under different loads is tested.

[0075] A flow meter is set on the pipeline simulated by the main engine and generator. The flow meter can feed back the measured flow data to the corresponding flow sensor, and this sensor then feeds back the pipeline flow data to the control module 18. The control module 18 will adjust the valve opening of the control valve after the flow meter to control the air supply flow rate of the main engine and generator. When the gas consumption of the main engine generator increases, the control module 18 will increase the valve opening of the flow control valve to increase the gas flow rate and achieve an increase in the load of the main engine generator; when the gas consumption of the main engine generator decreases, the control module will decrease the valve opening of the flow control valve to reduce the gas flow rate and achieve a decrease in the load of the main engine generator. During the static load test, the valve opening is sequentially tested under different working conditions such as 100%, 75%, and 50% of the load of the main engine generator; during the dynamic load test, the control module 18 can control the dynamic change of the load of the flow regulating valve, such as changing dynamically from 100% to 75% of the load, so as to test the air supply stability of the system. The air supply stability of the system is judged based on the data of the pressure sensors, temperature sensors, flow meters, etc. set in the entire test system equipment group and working pipeline. If, with the change of the load of the pipeline simulated by the main engine generator, the changes in the flow rate, pressure, etc. of each part of the entire test system can be stably within the reasonable design requirements of the equipment or pipeline, it is considered that the system can achieve stable air supply to the main engine generator.

[0076] Specifically, the methods of the three air supply test processes are described as follows:

[0077] (1) Compressor air supply test

[0078] During the compressor gas supply test, LNG is discharged from the storage tank 3 through the gas pump 1, completely vaporized through the LNG air-cooled vaporizer 4 and the water bath vaporizer 5, and enters the low-temperature natural gas tanks 6-8. The isolation valve at the initial stage of entering the compressor 9 is closed. When the natural gas in all the low-temperature natural gas tanks 6-8 reaches certain requirements, the isolation valve in front of the compressor 9 is opened to supply gas to the compressor, and then it enters the main engine and generator simulation pipeline through the buffer tank 10, and then returns to the low-temperature natural gas tank 6 through the normal-temperature NG tank 11 and the natural gas cooler 12 to form a large cycle. After the large cycle can operate stably under the base load condition, the gas supply stability test under different load conditions is started. After the test is completed, the excess natural gas can return to the LNG storage tank 3 through the boil-off gas re-liquefaction device 13.

[0079] When the load of the main engine increases, the gas consumption of the main engine generator increases, and the pressure of the buffer tank 10 decreases. The control module 18 can adjust the valve opening of the flow regulating valve 29 at the pump outlet to increase the gas supply flow. At the same time, it can change the valve opening of the control valve 27 in front of the compressor to keep the inlet pressure of the compressor maximum within the allowable range, and then maintain the pressure stability of the buffer tank 10 by adjusting the compressor speed.

[0080] When the load of the main engine decreases, the gas consumption of the main engine generator decreases, and the pressure of the buffer tank 10 increases. To maintain the pressure stability, the control module can adjust the valve opening of the flow regulating valve 29 at the pump outlet to reduce the gas supply flow, and at the same time reduce the compressor speed. If the pressure of the buffer tank 10 still rises, further control the valve opening of the control valve 27 in front of the compressor to decrease, so as to reduce the gas supply flow.

[0081] Under different load tests, monitor the changes of flow, pressure, temperature, etc. of each part of the entire compressor gas supply test system, and feedback the collected values to the control module 18 for comparison and analysis with the set values. If it is within the design range, the compressor gas supply system is considered stable.

[0082] (2) Forced boil-off gas plus LD heater gas supply test

[0083] During the forced boil-off gas plus LD heater gas supply test, LNG is discharged from the storage tank 3 through the gas pump 2, and the pressure and temperature of the natural gas reach the gas supply requirements of the main engine generator through the forced vaporizer 14, the gas-liquid separator 15 and the heater 16. Then, after being stabilized by the buffer tank 10, it enters the main engine and generator simulation pipeline. During the test, the excess natural gas returns to the LNG storage tank 3 through the boil-off gas re-liquefaction device 13 to form a large cycle. After the large cycle can operate stably under the base load condition, the gas supply stability test under different load conditions is started.

[0084] When the load of the main engine increases, the gas consumption of the main engine generator increases, and the pressure of the buffer tank 10 decreases. The control module 18 can increase the valve opening of the control valve 28 in front of the forced vaporizer 14 to increase the gas supply.

[0085] When the load of the main engine decreases, the gas consumption of the main engine generator decreases, and the pressure in the buffer tank 10 increases. To maintain pressure stability, the control module 18 can reduce the valve opening of the control valve 28 in front of the forced vaporizer 14 to reduce the gas supply.

[0086] Under different load tests, monitor the changes in flow rate, pressure, temperature, etc. of each part of the entire forced evaporation gas supply test system, and feedback the collected values to the control module for comparison and analysis with the set values. If it is within the design range, the system gas supply is considered stable.

[0087] (3) Combined gas supply test

[0088] During the combined gas supply test, two low-temperature gas pumps 1-2 are started simultaneously. Compressor gas supply is preferred. When the compressor gas supply cannot meet the requirements of the main engine generator, forced evaporation gas supply is used.

[0089] When the load of the main engine increases, the gas consumption of the main engine generator increases, and the pressure in the buffer tank 10 decreases. The control module 18 can adjust the valve opening of the flow control valve 29 at the pump outlet to increase the gas supply flow rate. At the same time, it can change the valve opening of the control valve 27 in front of the compressor 9 to keep the intake pressure of the compressor at the maximum within the allowable range, and then maintain the pressure stability of the buffer tank by adjusting the compressor speed. When the intake pressure and speed of the compressor 9 are maintained at the maximum and still cannot meet the gas demand of the main engine generator, it is necessary to make up the gas volume required for the main engine combustion through forced evaporation. At this time, the control module can increase the valve opening of the control valve 28 in front of the forced vaporizer 14 to increase the gas supply.

[0090] When the load of the main engine decreases, the gas consumption of the main engine generator decreases, and the pressure in the buffer tank 10 increases. To maintain pressure stability, the control module 18 can adjust the valve opening of the flow control valves 29-30 at the pump outlet to reduce the gas supply flow rate, and at the same time reduce the compressor speed. If the pressure in the buffer tank still rises, further control the valve opening of the control valve 27 in front of the compressor to decrease; if the gas supply is still higher than the demand of the main engine generator, the control system reduces the valve opening of the control valve 28 in front of the forced vaporizer 14 to reduce the gas supply.

[0091] Under different load tests, monitor the changes in flow rate, pressure, temperature, etc. of each part of the entire test system, and feedback the collected values to the control module for comparison and analysis with the set values. If it is within the design range, the system gas supply is considered stable.

[0092] S3. After the test, perform operations such as heating up, inerting, and purging the pipeline.

[0093] Specifically, after the operation is completed, close the inlet and outlet control valves of the LNG storage tank 3 and the NG tanks 6-8. Use the LNG vapor heated by the pipeline heating system to evaporate the LNG in the remaining pipelines of the test system and raise the temperature of the pipeline system. Then, introduce an inert gas to inertize the test system. Finally, replace the inert gas with dry air to keep the test system at the normal temperature working pressure and temperature. After the operation is completed, gradually shut down all equipment.

[0094] The test platform and method of the boil-off gas treatment and utilization integrated system provided by the embodiments of the present application use LNG as fuel, effectively reducing greenhouse gas emissions and lowering the energy efficiency design index of ships. It has two ways of supplying gas, namely compressor gas supply and forced vaporizer gas supply. When the compressor gas supply is insufficient, a combined gas supply mode can be adopted, which can meet the fuel gas supply requirements of the main engine and generator under different load conditions and ensure the stable operation of the system. The test device can provide a test platform for domestic low-temperature marine equipment in the future, which is conducive to achieving technological breakthroughs in related industries in China and reducing shipbuilding costs. An emergency cut-off valve is installed at the inlet of the main engine generator simulation pipeline, which can cut off the LNG supply emergently in case of an emergency to ensure the test safety.

[0095] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the above-mentioned division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. In addition, the specific names of the functional units and modules are only for the convenience of mutual distinction and do not limit the protection scope of the present application.

[0096] It should be clear that the embodiments in this specification are all described in a progressive manner. The same or similar parts between the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments. For the method embodiments, the relevant parts can refer to the partial description of the device embodiments (adopted according to the writing situation). The present application is not limited to the specific steps and structures described above and shown in the figures. And, for the sake of brevity, the detailed description of known method technologies is omitted here.

[0097] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A test platform for an integrated system of evaporation gas treatment and utilization, characterized in that The test platform includes an LNG supply system, a natural gas supply subsystem, an evaporation gas treatment and utilization system equipment group, a gas-consuming user simulation system, and a control hardware system; The LNG supply system includes an LNG storage tank, a first cryogenic gas pump, a second cryogenic gas pump, a first pipe group, and a first valve group; The natural gas supply subsystem includes a cryogenic natural gas tank, a natural gas cooler, a second pipe group, and a second valve group; The evaporation gas treatment and utilization system equipment group includes a compressor, a forced evaporator, a gas-liquid separator, an LD heater, a buffer tank, an LNG air temperature heater, a water bath vaporizer, a reflux air temperature heater, an evaporation gas re-liquefaction device, a third pipe group, and a third valve group; The gas-consuming user simulation system includes a high-pressure normal-temperature natural gas storage tank, a fourth pipe group, and a fourth valve group; The control hardware system includes all temperature sensors, pressure sensors, flow meters, flow sensors, and an integrated control module in the test platform.

2. The test platform according to claim 1, characterized in that, The first pipe group includes an LNG supply main pipe, a first LNG supply branch pipe, a second LNG supply branch pipe, a first LNG supply return pipe, a second LNG supply return pipe, and an LNG supply return main pipe; the first valve group includes all control valves, check valves, and isolation valves on the first pipe group; The first cryogenic gas pump is connected to the first LNG supply branch pipe, and the second cryogenic gas pump is connected to the second LNG supply branch pipe; the first LNG supply branch pipe and the second LNG supply branch pipe are in parallel and are both connected to the LNG supply main pipe; The first LNG supply return pipe is connected to the first LNG supply branch pipe, and the second LNG supply return pipe is connected to the second LNG supply branch pipe; the first LNG supply return pipe and the second LNG supply return pipe are in parallel and are both connected to the LNG supply return main pipe; the LNG supply return main pipe is connected to the LNG storage tank.

3. The test platform according to claim 1, characterized in that The number of the cryogenic natural gas tanks is three. The liquefied natural gas first passes through the first cryogenic natural gas tank and then enters the second cryogenic natural gas tank or the third cryogenic natural gas tank; The second pipe group includes a first NG supply main pipe before the first cryogenic natural gas tank, a second NG supply main pipe after the first cryogenic natural gas tank, a first NG supply branch pipe before the second cryogenic natural gas tank, a second NG supply branch pipe after the second cryogenic natural gas tank, a third NG supply branch pipe before the third cryogenic natural gas tank, a fourth NG supply branch pipe after the third cryogenic natural gas tank, a first NG connection bypass pipe between the second cryogenic natural gas tank and the third cryogenic natural gas tank, and a fifth NG supply branch pipe between the natural gas cooler and the first cryogenic natural gas tank; the second valve group includes all control valves, isolation valves, and check valves on the second pipe group; The first NG supply branch pipe and the third NG supply branch pipe are in parallel, the second NG supply branch pipe and the fourth NG supply branch pipe are in parallel, and the first NG supply branch pipe and the third NG supply branch pipe are jointly connected to the second NG supply main pipe.

4. The test platform according to claim 1, characterized in that, The third pipe group includes the sixth to sixteenth NG supply branch pipes, a heavy component return pipe, a main host gas supply pipe, and a steam return pipe; the third valve group includes all control valves, isolation valves, and check valves on the third pipe group.

5. The test platform according to claim 2-4, characterized in that, The LNG supply main pipe is connected to an LNG air temperature heater, the LNG air temperature heater is connected to a water bath vaporizer through the sixth NG supply branch pipe, the outlet of the water bath vaporizer is connected to the first NG supply main pipe, the second NG supply branch pipe and the fourth NG supply branch pipe are jointly connected to the seventh NG supply branch pipe, the inlet of the compressor is connected to the seventh NG supply branch pipe, and the outlet of the compressor is connected to the eighth NG supply branch pipe; The outlet of the forced evaporator and the inlet of the gas-liquid separator are connected through the ninth and tenth NG supply branch pipes. The steam at the outlet of the forced evaporator can also return to the LNG storage tank through the ninth supply branch pipe and the steam return pipe; The outlet of the gas-liquid separator and the inlet of the LD heater are connected through the eleventh NG supply branch pipe. The outlet of the LD heater is connected to the twelfth NG supply branch pipe. The eighth NG supply branch pipe and the twelfth NG supply branch pipe are jointly connected to the main host gas supply pipe. The sixteenth NG supply branch pipe is also connected to the main host gas supply pipe. The sixteenth NG supply branch pipe is connected to the buffer tank. The heavy components separated by the gas-liquid separator are connected to the inlet of the return air temperature heater through the heavy component return pipe. The outlet of the return air temperature heater is connected to the low-temperature natural gas tank through the fifteenth NG supply branch pipe; The inlet of the boil-off gas re-liquefaction device is connected to the thirteenth NG supply branch pipe; the outlet of the boil-off gas re-liquefaction device is connected to the LNG storage tank through the fourteenth NG supply branch pipe.

6. The test platform according to claim 1, characterized in that, The fourth pipe group includes a main host simulation main pipe, a generator simulation main pipe, a seventeenth NG supply branch pipe, and an eighteenth NG supply branch pipe; the fourth valve group includes all control valves, isolation valves, check valves, and emergency cut-off valves on the fourth pipe group; The main host simulation main pipe and the generator simulation main pipe are in parallel and are both connected to the main host gas supply pipe and the seventeenth NG supply branch pipe; the high-pressure normal-temperature natural gas storage tank and the natural gas cooler are connected through the eighteenth NG supply branch pipe; the inlet of the high-pressure normal-temperature natural gas storage tank is connected to the main host simulation main pipe and the generator simulation main pipe; the thirteenth NG supply branch pipe is connected to the main host simulation main pipe.

7. The test platform according to claim 1, wherein All temperature sensors, pressure sensors, flow meters, and flow sensors in the control hardware system are connected to the integrated control module. The integrated control module is used to receive the data transmitted by the sensors and make corresponding feedback. If the data such as pipeline pressure and flow rate exceeds the set value during the test, the integrated control module can make an alarm and urgently control the opening of the corresponding valves for feedback adjustment.

8. A testing method for an evaporation gas treatment and utilization integrated system, characterized in that, It is implemented based on the test platform according to any one of claims 1 to 7; the test method includes: Check all integrated system test devices and blow and wash the entire pipeline system; Adjust the valve opening of the control valves on the main host and generator simulation pipelines to change the gas supply flow rate, and conduct system gas supply stability tests under different loads. The tests include compressor gas supply tests, forced evaporation gas plus LD heater gas supply tests, and combined gas supply tests of the compressor and the forced evaporator; After the test, perform operations such as heating up, inerting, and purging the pipeline.

9. The testing method according to claim 8, wherein Inspect all integrated system test devices and purge the entire pipeline system, including: Check the connection of each device in the entire test system, check whether there is leakage at each pipeline connection, detect the airtightness of the pipeline system, and check whether the control hardware system is working properly; Inject inert gas into the pipeline system to purge its pipeline to make it in an inert state. After the entire pipeline system is in an inert state, perform a precooling operation on the test system.

10. The test method according to claim 8, characterized in that, After the test is completed, perform operations such as heating up, inerting, and purging the gas on the pipeline, including: After the operation is completed, use the LNG steam heated by the pipeline heating system to evaporate the LNG in the test system pipeline and raise the temperature of the pipeline system; Inject inert gas to make the test system inert, and finally replace the inert gas with dry air to keep the test system at normal temperature working pressure and temperature.

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