RU2360179C2 - Method and device for co2 transportation - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: invention is related to transportation and supply of liquid CO₂ into accumulating tank. Method for transportation of liquid CO₂, including its pumping in liquid phase, which differs by the fact that CO₂ flow is controlled by actuating mechanism, which provides for pressure in the range from 6.0…7.5 MPa, at that they control whether pressure and temperature correspond to values appropriate for liquid phase. Device for transportation of CO₂ liquid phase comprises balloons, actuating mechanism of flow control, flow metre, pressure and temperature detectors, safety valve for emergency discharge of liquid CO₂ and valve for prevention of pressure drop in case of sharp growth in consumption of user.

EFFECT: reduced power inputs in process of CO₂ supply to user at long distance due to maintenance of its parametres that correspond to liquid state, with the help of automated system of flow control.

2 cl, 1 dwg

Description

The invention relates to pipeline transport of liquefied gases, in particular to the transportation and distribution of liquid carbon dioxide CO ₂ in cylinders.

The closest analogue of the claimed method is a method for transporting liquid CO ₂ , including its pumping in the liquid phase (see AS USSR No. 1100458, F17C 7/04, 1984 (1)).

The disadvantage of this method is the unreliability of work, the inability to supply the consumer for an extended distance CO ₂ in liquid form.

The purpose of the invention in terms of the method is to reduce energy consumption when supplying CO ₂ to the consumer over an extended distance by maintaining its parameters corresponding to the liquid state using an automated flow control system.

This goal is achieved due to the fact that in the method of transporting liquid CO ₂ , including its pumping in the liquid phase, according to the invention, the flow of CO _{2 is} regulated by an actuator providing a pressure in the range of 6.0 ... 7.5 MPa, while controlling the pressure and temperature values corresponding to the liquid phase.

The closest analogue of the claimed device is a device for transporting liquid CO ₂ containing cylinders (see (1)).

The disadvantage of this installation is the design complexity and, as a consequence, the unreliability of operation, the inability to supply the consumer over an extended distance CO ₂ in liquid form.

The purpose of the invention in terms of the device is to reduce energy consumption when supplying CO ₂ to the consumer over an extended distance by maintaining its parameters corresponding to the liquid state using an automated flow control system.

This is achieved by the fact that the device for transporting liquid CO ₂ containing cylinders, according to the invention, is equipped with an actuating mechanism for regulating the flow, a flow meter, temperature and pressure sensors, a safety valve for emergency relief of liquid CO ₂ and a valve to prevent pressure drop during a sharp increase in consumption by the consumer.

The supply of liquid CO _{2 to} consumers, in contrast to gaseous CO ₂ , is more economical. For the same CO ₂ consumption by mass G [kg / h], the average rate of its transportation through a pipeline with an inner diameter d will be v = 4G / (πd ² ρ). At G = 220 kg / h, d = 50 mm, for the gaseous phase (ρ _g = 2 kg / m ³ ), the speed v _Г = 15.6 m / s, for the liquid phase (ρ _g = 950 kg / m ³ ) speed v _w = 0.03 m / s. In this case, the ratio of pressure losses to overcome friction forces, approximately proportional to the corresponding compressor capacities and, consequently, to technological costs, when pumping СО ₂ in the gaseous and liquid phases, will be Δр _g / Δр _ж = (ρ _g v _g ² ) / (ρ _ж v _w ² ) = 570. This calculation shows that the transfer of CO ₂ in the liquid phase will require 570 times less energy than the corresponding transfer of it in the gaseous phase.

The essence of the invention is as follows. The process of transition of a substance from one state of aggregation to another proceeds with a change in temperature and pressure. For example, the process of transition of liquid CO ₂ transported through a pipeline into the gaseous phase is accompanied by a change in temperature and pressure. The stresses arising from this lead to deformations in the pipelines and their ruptures.

In the proposed method and device, aggregate transitions are prevented by the fact that the state parameters - pressure and temperature are maintained in the range corresponding to the liquid phase in the state diagram of CO ₂ using an automated flow control system.

The drawing shows a diagram of a device that implements the method.

Example. The proposed device includes an actuator (1), a flow meter (2), temperature (3) and pressure sensors (4), an emergency relief valve for liquid CO ₂ (5), a shut-off valve (6), a storage tank (7), a pipeline (8), an object communication device (USO) (9), an operator's automated workstation (AWS) (10).

The described device operates as follows.

Liquid CO _{2 is} transported via an insulated pipe (8) to a storage tank (7). The flow rate is regulated by the actuator (1) and is controlled by the flowmeter (2). The pressure sensors (4) and temperature (3) are installed on the pipeline. The signals from the flow meter (2), pressure sensors (4), temperature (3) enter the communication device with the object (USO) (9), and through it to the automated workstation (AWP) of the operator (10). USO converts the measured parameters into unified electrical signals that are continuously processed by the computer in the workstation. The computer controls whether the physical parameters of the state — pressure and temperature — belong to their values on the CO ₂ state diagram corresponding to the liquid phase. Based on the values of pressure and temperature and the speed of their change, options are proposed for the operator to act, which either allows the system to work automatically or takes control. The pressure in the range of 6.0 ... 7.5 MPa is supported by the flow regulator (1), while the temperature of liquid CO ₂ at the inlet to the pipeline is maintained in the range of -30 ... + 30 ° С.

The shut-off valve (6) is designed to prevent pressure drops during a sharp increase in flow rate at the consumer. In order to avoid a sharp decrease in pressure below a predetermined limit (6.0 MPa), the pipeline overlaps and thereby maintains pressure within specified limits. The safety valve (5) is used for emergency discharge of liquid CO ₂ with an unacceptably sharp increase in pressure.

Claims (2)

1. The method of transporting liquid CO ₂ , including its pumping in the liquid phase, characterized in that the flow of CO ₂ regulate the actuator, providing a pressure in the range of 6.0 ... 7.5 MPa, while controlling the belonging of pressure and temperature to the values corresponding to the liquid phase. 2. A device for transporting liquid CO ₂ containing cylinders, characterized in that it is equipped with an actuator for controlling flow, a flow meter, temperature and pressure sensors, a safety valve for emergency relief of liquid CO ₂ and a valve to prevent pressure drop during a sharp increase in consumption by the consumer.