Energy supply system of floating type production oil storage and discharge device and floating type production oil storage and discharge device

Abstract

The invention relates to an energy supply system of a floating production oil storage and offloading device, the floating production oil storage and offloading device is high in efficiency, and the floating production oil storage and offloading device comprises a first-stage high-pressure compressor and a second-stage high-pressure compressor which are respectively communicated with a gas inlet and a gas outlet of a water / hydrocarbon dew point adjusting unit; a gas inlet of the high / low pressure gas treatment unit is communicated with a gas outlet of the water / hydrocarbon dew point adjusting unit; the dual-fuel engine is used for supplying power to a whole ship power grid; the fuel gas turbine coaxially drives the first-stage high-pressure compressor and the second-stage high-pressure compressor, a fuel gas inlet of the fuel gas turbine is communicated with a gas outlet of the high / low-pressure fuel gas treatment unit, a flue gas outlet of the fuel gas turbine is connected with a waste heat recovery unit, and the waste heat recovery unit is communicated with a hot water pipe network to form a heating loop; a fuel gas inlet of the fuel gas methane value increasing unit is communicated with a gas outlet of the water / hydrocarbon dew point adjusting unit, and a fuel gas outlet of the fuel gas methane value increasing unit is communicated with a fuel gas inlet of the dual-fuel engine.

Description

Technical Field

[0001] The present application relates to the technical field of floating production devices, and in particular to an energy supply system of a floating production storage and offloading device. Background Art

[0002] Traditional FPSOs (Floating, Production, Storage and Offloading) are usually powered by gas turbines (GTGs), in which the gas turbine drives the generator and the flue gas is heated by the waste heat recovery system. However, the gas turbine system occupies a large area, has a high process complexity, has a low efficiency of a single gas turbine, has a high investment cost, and a long delivery cycle.

[0003] Dual Fuel Engine (DFE) is commonly used to drive or power floating equipment such as offshore oil and gas platforms / LNGC (Liquefied Natural Gas Carrier) / merchant ships. It has low investment cost and process complexity, and its power generation efficiency is higher than that of gas turbines.

[0004] The methane number (MN) of the fuel gas required by DFE is relatively high, but the methane content of the associated gas produced by FPSO oil fields is usually relatively low, and usually contains more heavier components above C2, with a methane number usually below 60. When a dual-fuel engine uses this type of fuel gas, it is difficult to burn fully, explosion vibration is prone to occur, affecting the service life, and there is a greater safety risk. Summary of the invention

[0005] Based on this, it is necessary to propose an energy supply system for a floating production storage and offloading device, which can solve the problems of low efficiency and complex process of the existing energy supply system. A floating production storage and offloading device is also proposed.

[0006] According to one aspect of the present application, a power supply system for a floating production storage and offloading device comprises: a primary high-pressure compressor and a secondary high-pressure compressor, which are respectively located upstream and downstream of a water / hydrocarbon dew point regulating unit in a natural gas production system and are respectively connected to an air inlet and an air outlet of the water / hydrocarbon dew point regulating unit; a dual-fuel engine, which is used to supply power to the entire shipboard power grid of the floating production storage and offloading device; a high / low pressure gas processing unit, which is connected to an air outlet of the water / hydrocarbon dew point regulating unit; and a gas turbine, which coaxially drives the primary high-pressure compressor and the secondary high-pressure compressor. a high-pressure compressor, the gas inlet of the gas turbine is connected to the gas outlet of the water / hydrocarbon dew point regulating unit, the flue gas outlet of the gas turbine is connected to a waste heat recovery unit, the waste heat recovery unit is connected to the hot water pipeline network of the floating production storage and offloading device and constitutes a heating circuit; a fuel gas methane value improving unit, the fuel gas methane value improving unit is configured to improve the methane value of the fuel gas, the gas inlet of the fuel gas methane value improving unit is connected to the gas outlet of the water / hydrocarbon dew point regulating unit, and the gas outlet of the fuel gas methane value improving unit is connected to the gas inlet of the dual-fuel engine.

[0007] In some embodiments, the high / low pressure gas processing unit includes a high pressure flow path and a low pressure flow path, the high pressure flow path is connected to the gas inlet of the gas turbine, and the low pressure flow path is connected to the gas using equipment on the floating production storage and offloading unit.

[0008] In some embodiments, the fuel gas methane number improvement unit includes: a dehydration unit, the inlet of the dehydration unit is connected to the outlet of the water / hydrocarbon dew point adjustment unit; a refrigeration unit, the refrigeration unit includes a first heat exchange channel, a second heat exchange channel and a third heat exchange channel, the first heat exchange channel is used to cool the gas flowing out of the dehydration unit; a gas-liquid separator, the gas phase inlet of the gas-liquid separator is connected to the outlet of the first heat exchange channel, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the second heat exchange channel, and the gas phase outlet of the gas-liquid separator is connected to the inlet of the third heat exchange channel.

[0009] In some embodiments, an outlet of the second heat exchange channel is in communication with the water / hydrocarbon dew point adjustment unit.

[0010] In some embodiments, the refrigeration unit includes a first cold recovery heat exchanger, a refrigerant evaporator, a second cold recovery heat exchanger and a third cold recovery heat exchanger, each of which is provided with a part of the first heat exchange channel and is connected in sequence; wherein the refrigerant evaporator is connected to a refrigeration module and constitutes a refrigeration cycle; the second heat exchange channel is provided in the second cold recovery heat exchanger; the third heat exchange channel includes a first part provided in the third cold recovery heat exchanger and a second part provided in the first cold recovery heat exchanger, the inlet of the first part is connected to the gas phase outlet of the gas-liquid separator, the outlet of the first part is connected to the inlet of the second part, and the outlet of the second part is connected to the gas phase inlet of the gas pressure stabilizing buffer tank; the gas outlet of the gas pressure stabilizing buffer tank is connected to the gas inlet of the dual-fuel engine.

[0011] In some embodiments, a first throttling expansion valve is provided between the third cooling recovery heat exchanger and the gas-liquid separator, and the first throttling expansion valve reduces the pressure and cools the gas flowing out of the third cooling recovery heat exchanger.

[0012] In some embodiments, a second throttling expansion valve is provided between the gas phase outlet of the gas-liquid separator and the first portion of the third heat exchange channel, and the second throttling expansion valve reduces the pressure and cools the gas flowing out of the gas-liquid separator.

[0013] In some embodiments, the liquid outlet of the gas pressure stabilizing buffer tank is connected to the liquid inlet of the crude oil separation unit in the natural gas production system.

[0014] In some embodiments, the refrigeration module is a mechanical refrigeration module.

[0015] Another aspect of the present application provides a floating production storage and offloading device, including the energy supply system of the floating production storage and offloading device.

[0016] In the energy supply system of the floating production storage and offloading device of the present application, the natural gas produced by the FPSO is used to burn a turbine to drive a first-stage high-pressure compressor and a second-stage high-pressure compressor, and a waste heat recovery unit is included to provide heat for various process units of the entire ship; the processed natural gas produced by the FPSO is used as the fuel gas of the dual-fuel engine, and there is no risk of explosion when it is used, and the engine does not need to reduce power to operate, which solves the technical bottleneck that the natural gas produced by the FPSO cannot be used on the engine. Compared with the conventional technology using gas turbines, the process is simple, the functional efficiency is high, the total investment cost is significantly reduced, and the delivery period of the power generation system is significantly shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of a floating production storage and offloading device including an energy supply system of the floating production storage and offloading device according to an embodiment of the present application.

[0018] Figure 2 This is a schematic diagram of the composition of the gas methane value enhancement unit in the energy supply system of the floating production storage and offloading unit.

[0019] Description of reference numerals:

[0020] 100. Floating production storage and offloading unit; 1. Hull; 21. Crude oil separation and stabilization unit; 22. Low-pressure process compressor; 23. Medium-pressure process compressor; 24. Water / hydrocarbon dew point adjustment unit; 3. Hot water pipe network; 4. Ship-wide power grid; 5. Topside module; 61. First-stage high-pressure compressor; 62. Second-stage high-pressure compressor; 63. Dual-fuel engine; 64. Gas turbine; 65. Fuel gas methane value enhancement unit; 651. Dehydration unit; 652 , refrigeration unit; 6521, first cooling recovery heat exchanger; 6522, refrigerant evaporator; 6523, second cooling recovery heat exchanger; 6524, third cooling recovery heat exchanger; 6255, refrigeration module; 653, gas-liquid separator; 654, gas pressure stabilizing buffer tank; 655, first throttling expansion valve; 656, second throttling expansion valve; 657, condensate electric heater; 66, waste heat recovery unit; 67, high / low pressure gas processing unit. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0022] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0023] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0024] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0026] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0027] refer to Figure 1 and Figure 2 , Figure 1 It is a structural schematic diagram of a floating production storage and offloading unit 100 including an energy supply system of the floating production storage and offloading unit 100 according to an embodiment of the present application. Figure 2 It is a schematic diagram of the composition of the gas methane value improvement system in the energy supply system of the floating production storage and offloading unit 100.

[0028] On one hand, the present application proposes an energy supply system for a floating production storage and offloading unit 100, which can solve the technical bottleneck that the FPSO process gas components cannot be used on the engine, eliminate safety risks, and solve the problems of low efficiency and complex process of existing energy supply systems.

[0029] To facilitate understanding of the energy supply system of the floating production storage and offloading device 100 of one aspect of the present application, the floating production storage and offloading device 100 involved in the present application is first briefly described.

[0030] The "low temperature" and "high temperature" used in the embodiments of the present application are relative concepts, which indicate that the temperature of high-temperature gas is higher than that of low-temperature gas, and "normal temperature" is the temperature between low temperature and high temperature; similarly, "low pressure" and "high pressure" are relative concepts, and the pressure of high-pressure gas is higher than that of low-pressure gas. Therefore, although the "low temperature", "high temperature", "normal temperature", "low pressure" and "high pressure" in the embodiments of the present application are not limited to specific values, they are clear protection scopes when used to express relative concepts.

[0031] The floating production storage and offloading unit 100 includes a hull 1. The hull 1 is equipped with a natural gas production system, a hot water pipe network 3, a ship-wide power grid 4, and other upper modules 5. The other upper modules 5 include, for example, a water treatment module, a flare, and the like.

[0032] The natural gas production system includes a crude oil separation and stabilization unit 21 , a low-pressure process compressor 22 , a medium-pressure process compressor 23 , and a water / hydrocarbon dew point adjustment unit 24 .

[0033] In the crude oil separation and stabilization unit 21, the crude oil passes through the three-stage oil / gas / water three-phase separator to fully separate the crude oil, produced water and associated gas. The crude oil and produced water are further sent to other process units of conventional FPSO (such as crude oil desalination, water treatment, etc.), and the associated gas has different destinations depending on the pressure generated.

[0034] In the present application, a high / medium / low pressure three-phase separator is provided in the crude oil separation and stabilization unit 21, and the medium / low pressure three-phase separator is respectively connected to the low pressure process compressor 22 and the medium pressure process compressor 23. The outlets of the low pressure process compressor 22 and the medium pressure process compressor 2 merge with the outlet of the high pressure three-phase separator. In this way, the gas produced by the low pressure / medium pressure three-phase separator is respectively compressed by the low pressure / medium pressure process compressor 23, and then merged with the gas produced by the high pressure three-phase separator and transported to the water / hydrocarbon dew point adjustment unit 24.

[0035] The water / hydrocarbon dew point adjustment unit 24 is used to adjust and control the water dew point and hydrocarbon dew point in the natural gas, and can be implemented by using existing technologies in the prior art.

[0036] refer to Figure 1The energy supply system of the floating production storage and offloading unit 100 of the present application includes a first-stage high-pressure compressor 61, a second-stage high-pressure compressor 62, a dual-fuel engine 63, a gas turbine 64, a fuel gas methane value enhancement unit 65, a waste heat recovery unit 66, and a high / low pressure gas processing unit 67.

[0037] Specifically, the first-stage high-pressure compressor 61 and the second-stage high-pressure compressor 62 are respectively located upstream and downstream of the water / hydrocarbon dew point regulating unit 24 in the natural gas production system, and are respectively connected to the air inlet and the air outlet of the water / hydrocarbon dew point regulating unit 24. The first-stage high-pressure compressor 61 is used to further compress the confluent airflow of the high / medium / low pressure three-phase separator and input it into the water / hydrocarbon dew point regulating unit 24. The second-stage high-pressure compressor 62 is used to further compress the natural gas treated by the water / hydrocarbon dew point regulating unit 24 and output it as product gas. The airflow flowing out of the air outlet of the water / hydrocarbon dew point regulating unit 24 includes two paths, one flowing to the second-stage high-pressure compressor 62, and the other flowing to the fuel gas methane value improvement unit 65.

[0038] The dual-fuel engine 63 is used to supply power to the whole ship power grid 4 of the floating production storage and offloading device 100. The dual-fuel engine 63 is responsible for supplying power to the whole ship power grid 4. The dual-fuel engine 63 can use gas or oil to generate electricity. The oil is, for example, diesel.

[0039] The gas turbine 64 coaxially drives the first-stage high-pressure compressor 61 and the second-stage high-pressure compressor 62, and the gas inlet of the gas turbine 64 is connected to the gas outlet of the high / low pressure gas processing unit 67. The gas inlet of the high / low pressure gas processing unit 67 is connected to the gas outlet of the water / hydrocarbon dew point adjustment unit 24, and the flue gas outlet of the gas turbine 64 is connected to the waste heat recovery unit 66, which is connected to the hot water pipe network 3 of the floating production storage and offloading unit 100 and forms a heating circuit.

[0040] The gas turbine 64 coaxially drives the primary high-pressure compressor 61 and the secondary high-pressure compressor 62, that is, the driving shaft of the gas turbine 64 is used to drive the primary high-pressure compressor 61 and the secondary high-pressure compressor 62, so there is no need to configure a separate driving mechanism for the primary high-pressure compressor 61 and the secondary high-pressure compressor 62. At the same time, the flue gas discharged by the gas turbine 64 recovers heat through the waste heat recovery unit 66 and supplies heat to the hot water pipe network 3 of the entire ship.

[0041] The fuel gas methane number improving unit 65 is configured to improve the methane number of the fuel gas. The gas inlet of the fuel gas methane number improving unit 65 is connected to the gas outlet of the water / hydrocarbon dew point adjustment unit 24, and the gas outlet of the fuel gas methane number improving unit 65 is connected to the gas inlet of the dual-fuel engine 63.

[0042] The fuel gas methane number increasing unit 65 reduces the content of heavy components above carbon 2 and increases the content of carbon 1 in the fuel gas, thereby increasing the methane number of the fuel gas, so that it meets the index and is supplied as fuel gas to the dual-fuel engine 63 to supply power to the ship's power grid 4. The treated natural gas is supplied as fuel gas to the dual-fuel engine 63, and there is no risk of explosion when it is used.

[0043] Optionally, the fuel gas methane number enhancement unit 65 uses direct freezing and pressure reduction separation technology to remove carbon dioxide and above components and enrich the methane component of the natural gas produced by the FPSO, which can enhance the methane number of the fuel gas from below 60 to a maximum of above 80.

[0044] The energy supply system of the floating production storage and offloading device 100 of the present application uses the natural gas produced by the FPSO to burn a turbine to drive a first-stage high-pressure compressor 61 and a second-stage high-pressure compressor 62, and includes a waste heat recovery unit 66 to provide heat for various process units on the entire ship; the processed natural gas produced by the FPSO is used as the fuel gas for the dual-fuel engine 63, and there is no risk of explosion when using it, and the engine does not need to reduce power to operate, which solves the technical bottleneck that the natural gas produced by the FPSO cannot be used on the engine. Compared with the conventional technology using gas turbines, the process is simple, the efficiency is high, the total investment cost is significantly reduced, and the delivery period of the power generation system is significantly shortened.

[0045] In some embodiments, the high / low pressure gas processing unit 67 includes a high pressure flow path and a low pressure flow path, the high pressure flow path is connected to the gas inlet of the gas turbine 64 , and the low pressure flow path is connected to the gas using equipment on the floating production storage and offloading unit 100 .

[0046] The high / low pressure gas processing unit 67 adjusts the pressure and temperature of the natural gas flowing out of the outlet of the water / hydrocarbon dew point regulating unit 24, and supplies the high pressure gas to the gas turbine 64 through the high pressure flow path, and supplies the low pressure gas to other gas-using equipment on the floating production storage and offloading unit 100 through the low pressure flow path.

[0047] refer to Figure 1 and Figure 2 The fuel gas methane number increasing unit 65 is used to provide the dual-fuel engine 63 with processed fuel gas with a methane number that meets the standard. In some embodiments, the fuel gas methane number increasing unit 65 includes a dehydration unit 651 , a refrigeration unit 652 and a gas-liquid separator 653 .

[0048] The inlet of the dehydration unit 651 is connected to the outlet of the water / hydrocarbon dew point adjustment unit 24. The air inlet of the dehydration unit 651 comes from the outlet of the water / hydrocarbon dew point adjustment unit 24. The dehydration unit 651 includes, for example, a molecular sieve dehydration system, which performs adsorption drying on the natural gas to reduce the water content, so as to ensure that no natural gas hydrate is generated in the subsequent process to cause freezing and blocking.

[0049] The refrigeration unit 652 includes a first heat exchange channel, a second heat exchange channel and a third heat exchange channel. The first heat exchange channel is used to cool down the gas flowing out of the dehydration unit 651.

[0050] The gas phase inlet of the gas-liquid separator 653 is connected to the outlet of the first heat exchange channel, the liquid phase outlet of the gas-liquid separator 653 is connected to the inlet of the second heat exchange channel, and the gas phase outlet of the gas-liquid separator 653 is connected to the inlet of the third heat exchange channel.

[0051] like Figure 2 As shown, in one example, the refrigeration unit 652 includes a first cold recovery heat exchanger 6521, a refrigerant evaporator 6522, a second cold recovery heat exchanger 6523 and a third cold recovery heat exchanger 6524, each of which is provided with a portion of the first heat exchange channel and is connected in sequence. The refrigerant evaporator 6522 is connected to a refrigeration module 6255 and forms a refrigeration cycle. The second heat exchange channel is provided in the second cold recovery heat exchanger 6523. The third heat exchange channel includes a first part provided in the third cold recovery heat exchanger 6524 and a second part provided in the first cold recovery heat exchanger 6521, the inlet of the first part is connected to the gas phase outlet of the gas-liquid separator 653, the outlet of the first part is connected to the inlet of the second part, and the outlet of the second part is connected to the gas phase inlet of the gas pressure stabilizing buffer tank 654; the gas outlet of the gas pressure stabilizing buffer tank 654 is connected to the gas inlet of the dual-fuel engine 63.

[0052] Specifically, in this embodiment, a portion of the first heat exchange channel is provided in each of the first cold recovery heat exchanger 6521, the refrigerant evaporator 6522, the second cold recovery heat exchanger 6523, and the third cold recovery heat exchanger 6524, and each portion is connected through a pipeline. The gas phase inlet of the gas-liquid separator 653 is connected to the outlet of the first heat exchange channel provided on the third cold recovery heat exchanger 6524.

[0053] The natural gas flowing out from the outlet of the dehydration unit 651 passes through the first cold recovery heat exchanger 6521, the refrigerant evaporator 6522, the second cold recovery heat exchanger 6523 and the third cold recovery heat exchanger 6524 in sequence for multiple cooling, and then reaches the gas phase inlet of the gas-liquid separator 653.

[0054] The first cold recovery heat exchanger 6521 and the third cold recovery heat exchanger 6524 both circulate the low-temperature and low-pressure gas processed by the downstream gas-liquid separator 653 to cool the gas with relatively high pressure and temperature that has not been processed by the gas-liquid separator 653. The natural gas flowing out of the gas phase outlet of the gas-liquid separator 653 flows through the third cold recovery heat exchanger 6524 and the first cold recovery heat exchanger 6521 in sequence. The first part and the second part of the third heat exchange channel can be connected by a pipeline.

[0055] The second cooling recovery heat exchanger 6523 uses the low-temperature heavy component condensate separated by the downstream gas-liquid separator 653 to circulate back to cool the fuel gas.

[0056] The refrigerant evaporator 6522 uses an external refrigeration module 6255 and directly cools the gas. The refrigerant evaporator 6522 and the refrigeration module 6255 form a refrigeration circuit. The refrigeration module 6255 can be, for example, a mechanical refrigeration module 6255. The mechanical refrigeration module 6255 includes, for example, a compressor, a condenser, and an expansion valve. The compressor sequentially transports the refrigerant through the condenser and the expansion valve to the inlet of the refrigerant evaporator 6522, and then returns to the compressor through the outlet of the refrigerant evaporator 6522.

[0057] In this design, the cooling effect of the refrigeration unit 652 is ensured by the refrigerant evaporator 6522 and the external refrigeration module 6255; at the same time, the temperature and enthalpy of the gas after being processed by the gas-liquid separator 653 are fully utilized, the overall energy consumption is reduced and the cooling performance is optimized. In addition, this four-stage cooling can reduce energy consumption and extend the life of the equipment.

[0058] It should also be pointed out that the composition scheme of the refrigeration unit 652 including three heat exchange channels is not limited to the above embodiment.

[0059] Furthermore, a first throttling expansion valve 655 is provided between the third cooling recovery heat exchanger 6524 and the gas-liquid separator 653 , and the first throttling expansion valve 655 reduces the pressure and cools the gas flowing out of the third cooling recovery heat exchanger 6524 .

[0060] Specifically, the natural gas flowing out of the first heat exchange channel on the third cold recovery heat exchanger 6524 first passes through the first throttling expansion valve 655, and then enters the gas phase inlet of the gas-liquid separator 653. The first throttling expansion valve 655 cools the natural gas flowing out of the first heat exchange channel. In this process, the natural gas is depressurized and cooled by the Joule-Thomson effect, and the temperature of the natural gas is further reduced, so that the heavy components above C2 are fully liquefied and enter the gas-liquid separator 653 for gas-liquid separation. At this time, the heavier components above C2 form condensate, which flows out from the liquid phase outlet of the gas-liquid separator 653 and is sent to the second heat exchange channel of the second cold recovery heat exchanger 6523. The second cold recovery heat exchanger 6523 recovers the cold of the condensate, and then heats it through the condensate electric heater 657, and then circulates it back to the natural gas production system.

[0061] Optionally, the outlet of the second heat exchange channel is connected to the water / hydrocarbon dew point adjustment unit 24. That is, the second cold recovery heat exchanger 6523 recovers the cold of the condensate, and then heats it through the condensate electric heater 657 and circulates it into the water / hydrocarbon dew point adjustment unit 24. Specifically, the water / hydrocarbon dew point adjustment unit 24 includes a multi-stage device, and the outlet of the second heat exchange channel is connected to a certain stage of the middle device.

[0062] Furthermore, a second throttling expansion valve 656 is provided between the gas phase outlet of the gas-liquid separator 653 and the first part of the third heat exchange channel, and the second throttling expansion valve 656 reduces the pressure and cools the gas flowing out of the gas-liquid separator 653 .

[0063] Specifically, after the natural gas with a methane value that meets the standard is processed by the gas-liquid separator 653 and flows out from the gas phase outlet of the gas-liquid separator 653, it is depressurized and cooled again by the second throttling expansion valve 656. This process is also based on the Joule-Thomson effect to achieve pressure reduction and temperature reduction, and the purpose is to release the unused mechanical energy of the natural gas and further use the enthalpy value of the natural gas for cooling. The natural gas with a methane value that meets the standard after processing enters the third cold recovery heat exchanger and the first cold recovery heat exchanger 6521 in order to recover the cold of the natural gas, and then enters the gas pressure stabilizing buffer tank 654 for pressure stabilization and buffering, and is then sent to the dual-fuel engine 63 of the hull 1 for use.

[0064] After the above process, most of the carbon dioxide components and above in the natural gas are separated into condensate, and the content of carbon one components in the remaining gas phase is high enough. Finally, the methane value of the overall component meets the engine intake requirements and will not cause the risk of detonation.

[0065] Further, in some embodiments, reference Figure 2 The liquid outlet of the gas pressure stabilizing buffer tank 654 is connected to the liquid inlet of the crude oil separation unit in the natural gas production system.

[0066] After entering the third cold recovery heat exchanger and the first cold recovery heat exchanger 6521 and undergoing pressure stabilization and buffering treatment in the fuel gas pressure stabilization buffer tank 654, the gas and liquid are separated, wherein the gas phase enters the dual-fuel engine 63 of the hull 1 for use; the liquid phase is circulated and sent to the crude oil separation unit.

[0067] In another aspect of the present application, a floating production storage and offloading device 100 is provided, including an energy supply system of the floating production storage and offloading device 100 .

[0068] The floating production storage and offloading unit 100 of the present application adopts the above-mentioned energy supply system, and can use the processed natural gas produced by the FPSO as the fuel gas of the dual-fuel engine 63. There is no risk of explosion when using it, and the engine does not need to reduce power to operate, which solves the technical bottleneck that the natural gas produced by the FPSO cannot be used on the engine. Compared with the conventional technology using gas turbines, the process is simple, the efficiency is high, the total investment cost is significantly reduced, and the delivery period of the power generation system is significantly shortened.

[0069] Finally, it should be noted that the various technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An energy supply system for a floating production storage and offloading unit, characterized in that: include: The first-stage high-pressure compressor and the second-stage high-pressure compressor are respectively located upstream and downstream of the water / hydrocarbon dew point regulating unit in the natural gas production system, and are respectively connected to the air inlet and the air outlet of the water / hydrocarbon dew point regulating unit; A high / low pressure gas processing unit, wherein the gas inlet of the high / low pressure gas processing unit is connected to the gas outlet of the water / hydrocarbon dew point regulating unit; A dual-fuel engine for supplying power to the entire shipboard power grid of the floating production storage and offloading unit; a gas turbine, wherein the gas turbine coaxially drives the first-stage high-pressure compressor and the second-stage high-pressure compressor, the gas inlet of the gas turbine is connected to the gas outlet of the high / low-pressure gas processing unit, the flue gas outlet of the gas turbine is connected to a waste heat recovery unit, and the waste heat recovery unit is connected to the hot water pipe network of the floating production storage and offloading device to form a heating circuit; A fuel gas methane number improving unit, wherein the fuel gas methane number improving unit is configured to improve the methane number of the fuel gas, the fuel gas methane number improving unit's fuel gas methane number improving unit's fuel gas inlet is connected to the gas outlet of the water / hydrocarbon dew point regulating unit, and the fuel gas methane number improving unit's fuel gas outlet is connected to the fuel gas inlet of the dual-fuel engine.

2. The energy supply system of the floating production storage and offloading unit according to claim 1, characterized in that: The high / low pressure gas processing unit comprises a high pressure flow path and a low pressure flow path, wherein the high pressure flow path is connected to the gas inlet of the gas turbine, and the low pressure flow path is connected to the gas using equipment on the floating production storage and offloading device.

3. The energy supply system of the floating production storage and offloading unit according to claim 1, characterized in that: The fuel gas methane value improving unit comprises: a dehydration unit, wherein the inlet of the dehydration unit is in communication with the outlet of the water / hydrocarbon dew point adjustment unit; A refrigeration unit, wherein the refrigeration unit comprises a first heat exchange channel, a second heat exchange channel and a third heat exchange channel, wherein the first heat exchange channel is used to cool the gas flowing out of the dehydration unit; A gas-liquid separator, wherein the gas phase inlet of the gas-liquid separator is connected to the outlet of the first heat exchange channel, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the second heat exchange channel, and the gas phase outlet of the gas-liquid separator is connected to the inlet of the third heat exchange channel.

4. The energy supply system of the floating production storage and offloading unit according to claim 3 is characterized in that: An outlet of the second heat exchange passage is in communication with the water / hydrocarbon dew point adjustment unit.

5. The energy supply system of the floating production storage and offloading unit according to claim 3, characterized in that: The refrigeration unit comprises a first cooling recovery heat exchanger, a refrigerant evaporator, a second cooling recovery heat exchanger and a third cooling recovery heat exchanger, each of which is provided with a portion of the first heat exchange channel and is connected in sequence; wherein, The refrigerant evaporator is connected to a refrigeration module to form a refrigeration cycle; The second heat exchange channel is provided in the second cold recovery heat exchanger; The third heat exchange channel includes a first part provided in the third cold recovery heat exchanger and a second part provided in the first cold recovery heat exchanger, the inlet of the first part is communicated with the gas phase outlet of the gas-liquid separator, the outlet of the first part is communicated with the inlet of the second part, and the outlet of the second part is communicated with the gas phase inlet of the gas pressure stabilizing buffer tank; The gas outlet of the gas pressure stabilizing buffer tank is in communication with the gas inlet of the dual-fuel engine.

6. The energy supply system of the floating production storage and offloading unit according to claim 5, characterized in that: A first throttling expansion valve is provided between the third cooling recovery heat exchanger and the gas-liquid separator, and the first throttling expansion valve reduces the pressure and cools the gas flowing out of the third cooling recovery heat exchanger.

7. The energy supply system of the floating production storage and offloading unit according to claim 5, characterized in that: A second throttling expansion valve is provided between the gas phase outlet of the gas-liquid separator and the first portion of the third heat exchange channel, and the second throttling expansion valve reduces the pressure and cools the gas flowing out of the gas-liquid separator.

8. The energy supply system of the floating production storage and offloading unit according to claim 5, characterized in that: The liquid outlet of the fuel gas pressure stabilizing buffer tank is communicated with the liquid inlet of the crude oil separation unit in the natural gas production system.

9. The energy supply system of the floating production storage and offloading unit according to claim 5, characterized in that: The refrigeration module is a mechanical refrigeration module.

10. A floating production storage and offloading unit, characterized in that: A power supply system comprising a floating production storage and offloading unit as claimed in any one of claims 1 to 9.

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