Liquid cargo processing system compatible with low-pressure liquefied CO2 and medium-pressure liquefied CO2

Abstract

A liquid cargo processing system compatible with low-pressure liquefied CO2 and medium-pressure liquefied CO2 is characterized in that a first liquefied CO2 storage tank is arranged in a liquefied CO2 storage terminal, a second liquefied CO2 storage tank is arranged in a liquefied CO2 transport ship, and the second liquefied CO2 storage tank is sequentially connected with a flow control valve, a lightering hose, a cargo metering skid and the first liquefied CO2 storage tank; the opening degree of the flow control valve is controlled by the pressure in the second liquefied CO2 storage tank; a branch pipeline extends out of an outlet of the cargo metering skid and is sequentially connected with the low-pressure CO2 buffer tank, the booster pump, the heater, the pressure control valve and the first liquefied CO2 storage tank, and a bypass pipeline extends out of the low-pressure CO2 buffer tank and is sequentially connected with the CO2 reliquefaction device and the first liquefied CO2 storage tank. The buffer tank, the booster pump, the reliquefaction device and other key equipment are introduced into the CO2 liquid cargo treatment system, and the problem that an offshore CO2 storage terminal receives and stores liquefied CO2 from CO2 transport ships with different pressure and temperature schemes can be effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of marine vessel design and construction, and specifically relates to a liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2. Background Technology

[0002] Effective matching between the transportation and storage ends of liquefied CO2 at sea is a key link in achieving efficient operation of the entire industry chain. At the transportation end, influenced by factors such as onshore facility capacity, transport volume, and distance, the maritime transport of liquefied CO2 mainly employs two storage schemes: low-temperature, low-pressure (-55℃, 8 barg) and medium-temperature, medium-pressure (-35℃, 19 barg), corresponding to two different types of liquefied CO2 transport vessels. In small-scale regional storage scenarios, the offshore CO2 storage end typically selects a pressure and temperature scheme consistent with the transport vessel. However, as the storage scale expands further, in cross-regional, clustered offshore carbon sequestration scenarios, the above matching method clearly cannot meet the storage requirements of liquefied CO2 from different carbon sources and with different temperature and pressure schemes. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a liquid cargo handling system compatible with both low-pressure and medium-pressure liquefied CO2. The aim is to enable the transfer of liquefied CO2 to a storage terminal via this system, regardless of whether the transport vessel employs a low-pressure or medium-pressure storage scheme. The technical solution adopted is as follows:

[0004] A liquefied cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 includes a first liquefied CO2 storage tank in a liquefied CO2 storage terminal and a second liquefied CO2 storage tank in a liquefied CO2 transport vessel. A cargo pump is installed in the second liquefied CO2 storage tank and is connected in sequence to a flow control valve, a transport hose, a cargo metering skid, and the first liquefied CO2 storage tank. The opening degree of the flow control valve is controlled by the pressure in the second liquefied CO2 storage tank.

[0005] The cargo metering skid has a branch pipe extending from its outlet, which is connected in sequence to a low-pressure CO2 buffer tank, a booster pump, a heater, a pressure control valve, and a first liquefied CO2 storage tank. The low-pressure CO2 buffer tank has a bypass pipe extending from its outlet, which is connected in sequence to a CO2 reliquefaction unit and a first liquefied CO2 storage tank.

[0006] The first liquefied CO2 storage tank is connected to the CO2 reliquefaction unit via a gasification pipeline.

[0007] Furthermore, in the aforementioned liquid cargo handling system compatible with both low-pressure and medium-pressure liquefied CO2, the flow control valve is a three-way valve, and the branch line of the three-way valve is connected to the cargo evaporator and returns to the second liquefied CO2 storage tank.

[0008] Furthermore, in the aforementioned liquid cargo handling system compatible with both low-pressure and medium-pressure liquefied CO2, a first valve is installed on the passage from the cargo metering skid to the first liquefied CO2 storage tank, and a second valve is installed on the passage from the cargo metering skid to the low-pressure CO2 buffer tank.

[0009] Furthermore, the aforementioned liquid cargo handling system, which is compatible with both low-pressure and medium-pressure CO2 liquefaction, further utilizes R407 as an intermediate refrigerant in its reliquefaction unit, with seawater providing the necessary cooling capacity.

[0010] Furthermore, the aforementioned liquid cargo handling system, which is compatible with both low-pressure and medium-pressure liquefied CO2, is further equipped with a pressure sensor and a temperature sensor at the heater outlet.

[0011] Furthermore, the aforementioned liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 further includes two first liquefied CO2 storage tanks within the liquefied CO2 storage terminal.

[0012] This invention effectively solves the problem of receiving and storing liquefied CO2 from CO2 transport vessels with different pressure / temperature schemes by introducing key equipment such as buffer tanks, booster pumps, and reliquefaction devices into the CO2 liquid cargo handling system, thus significantly improving the operational efficiency of the entire maritime CCUS industry chain. At the same time, since the storage terminal does not need to return gas to the transport vessel to balance the tank pressure during the transshipment process, the risk of cargo contamination between the two is avoided, and the invention has greater operational flexibility. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the system of the present invention;

[0014] Among them, 1-Liquefied CO2 transport ship, 2-Second liquefied CO2 storage tank, 3-Liquid cargo pump, 4-Flow control valve, 5-Cargo evaporator, 6-Transfer hose, 7-Liquefied CO2 storage terminal, 8-First liquefied CO2 storage tank, 9-Cargo metering skid, 10, 11-Manual valve, 12-Low-pressure CO2 buffer tank, 13-Boost pump, 14-Heater, 15-Pressure sensor, 16-Temperature sensor, 17-Pressure control valve, 18-CO2 reliquefaction unit. Detailed Implementation

[0015] The invention will be further described with reference to the accompanying drawings. Example

[0016] like Figure 1As shown, after the liquefied CO2 transport vessel 1 is in place, the liquefied CO2 in the second liquefied CO2 storage tank 2 is transferred to the flow control valve 4 via pipeline 001 using the cargo pump 3. Then, a portion of the liquefied CO2 is evaporated into gaseous CO2 by the cargo evaporator 5 via pipeline 003, and then returned to the second liquefied CO2 storage tank 2 via pipeline 004 to maintain stable pressure within the tank. The remaining liquefied CO2 is transferred to the sealing terminal 7 via pipeline 002, the transfer hose 6, and pipeline 005. The second liquefied CO2 storage tank 2 can adopt a low-temperature, low-pressure scheme of -55℃ and 8 barg, or a medium-temperature, medium-pressure scheme of -35℃ and 19 barg. The opening of the flow control valve is controlled by the pressure within the second liquefied CO2 storage tank 2. Preferably, the cargo evaporator 5 directly uses seawater as a heating source. The transfer hose 6 can be used for both low-pressure and medium-pressure liquefied CO2 transfer, with a design pressure of 25 barg and a design temperature of -55℃.

[0017] After the liquefied CO2 reaches the storage terminal via pipeline 005, it first passes through the cargo metering skid 9 to measure the liquid volume. The preferred method for the metering skid 9 is to use a Coriolis mass flow meter.

[0018] After passing through metering skid 9, if the CO2 received from the transport ship is at medium temperature and medium pressure, valve 10 is opened and valve 11 is closed. The liquefied CO2 is then injected into the first liquefied CO2 storage tank 8 of the storage terminal 7 via pipelines 006 and 007. The first liquefied CO2 storage tank 8 adopts a medium-pressure design with a design pressure of 19 barg and a design temperature of -35℃.

[0019] If the CO2 received from the transport ship is low-temperature, low-pressure CO2, valve 11 is opened and valve 10 is closed. The liquefied CO2 is injected into the low-pressure CO2 buffer tank 12 via pipeline 008 to ensure stable suction pressure at the booster pump 13. The low-pressure CO2 buffer tank 12 adopts a low-pressure design with a design pressure of 8 barg and a design temperature of -55℃. The CO2 gas discharged from the low-pressure CO2 buffer tank 12 is transported to the reliquefaction unit 18 via pipeline 009 for liquefaction. The liquefied CO2 is then injected into the first liquefied CO2 storage tank 8 via pipelines 010 and 007.

[0020] The liquefied CO2 in the low-pressure CO2 buffer tank 12 is first pressurized by the booster pump 13, and then heated by the heater 14 to meet the storage conditions of the first liquefied CO2 storage tank 8. It is then injected into the first liquefied CO2 storage tank 8 via pipelines 011 and 007. Pipeline 011 is equipped with a pressure sensor 15, a temperature sensor 16, and a pressure control valve 17. When the liquefied CO2 pressure and temperature reach the set values, the pressure control valve 17 automatically opens to ensure that the liquefied CO2 injected into the first liquefied CO2 storage tank 8 meets its pressure and temperature requirements.

[0021] During the process of liquefied CO2 entering the first liquefied CO2 storage tank 8 via pipeline 007, the CO2 gas displaced in the tank enters the reliquefaction unit 18 via pipeline 012. The liquefied CO2 is then injected back into the first liquefied CO2 storage tank 8 via pipelines 010 and 007. Preferably, the reliquefaction unit 18 uses R407 as an intermediate refrigerant, with seawater providing the cooling capacity.

Claims

1. A liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2, characterized in that, The liquefied CO2 storage terminal is equipped with a first liquefied CO2 storage tank, and the liquefied CO2 transport ship is equipped with a second liquefied CO2 storage tank. The second liquefied CO2 storage tank is equipped with a liquid cargo pump, which is connected in sequence to a flow control valve, a transport hose, a cargo metering skid, and the first liquefied CO2 storage tank. The opening degree of the flow control valve is controlled by the pressure in the second liquefied CO2 storage tank. The cargo metering skid has a branch pipe extending from its outlet, which is connected in sequence to a low-pressure CO2 buffer tank, a booster pump, a heater, a pressure control valve, and a first liquefied CO2 storage tank. The low-pressure CO2 buffer tank has a bypass pipe extending from its outlet, which is connected in sequence to a CO2 reliquefaction unit and a first liquefied CO2 storage tank. The first liquefied CO2 storage tank is connected to the CO2 reliquefaction unit via a gasification pipeline.

2. The liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 according to claim 1, characterized in that, The flow control valve is a three-way valve, and the branch line of the three-way valve is connected to the cargo evaporator and returns to the second liquefied CO2 storage tank.

3. A liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 according to claim 1, characterized in that, A first valve is installed on the passage from the cargo metering skid to the first liquefied CO2 storage tank, and a second valve is installed on the passage from the cargo metering skid to the low-pressure CO2 buffer tank.

4. A liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 according to claim 1, characterized in that, The reliquefaction unit uses R407 as an intermediate refrigerant, with seawater providing the cooling capacity required for refrigeration.

5. A liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 according to claim 1, characterized in that, Pressure and temperature sensors are installed at the heater outlet.

6. A liquid cargo handling system compatible with low-pressure and medium-pressure liquefied CO2 according to claim 1, characterized in that, The liquefied CO2 storage terminal is equipped with two primary liquefied CO2 storage tanks.

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