A method for rapid discharge of LNG carrier vaporizer condensate

Abstract

The application discloses a kind of LNG ship vaporizer condensate water's quick discharge method, comprising the following steps: connecting a gas pipeline on the condensate water deposition pipe of vaporizer, control valve is set on gas pipeline, and control valve is linked with the liquid level sensor of vaporizer for detecting whether the water level in condensate water deposition pipe reaches first high alarm line;When the water level in condensate water deposition pipe reaches first high alarm line, control valve opens, and specific pressure of gas pipeline is connected into condensate water deposition pipe, and under the push of pressurized gas, condensate water in condensate water deposition pipe is quickly discharged to downstream pipeline.The application sets a gas pipeline on the condensate water deposition pipe of vaporizer, increases back pressure by condensate water discharge side, can quickly discharge condensate water from vaporizer, to ensure the stable operation of equipment, guarantee the safe use of natural gas system.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a method for rapid discharge of condensate from LNG ship vaporizers. Background Technology

[0002] On LNG carriers, LNG vaporizers and forced vaporizers are among the few heating devices that do not use liquefied natural gas as the heating medium. However, the heating medium for both of these devices is steam. The 300-400°C steam temperature and the -163°C natural gas exchange heat, producing a large amount of condensate. If the condensate drainage is not smooth, liquid accumulation will occur. Once a certain alarm level is reached, the equipment will be triggered to shut down in an emergency.

[0003] LNG vaporizers are mainly used during cooling tests and gas sea trials, while forced vaporizers are only used during gas sea trials or normal ship operations. Stable equipment operation is a prerequisite for ensuring safe navigation and management of the ship. Frequent start-ups and shutdowns, leading to system instability, inevitably increase manpower and material resources, causing unnecessary waste and increasing safety risks. Summary of the Invention

[0004] In view of this, the present invention provides a method for rapid discharge of condensate from an LNG ship vaporizer. By setting a gas pipeline on the condensate deposition pipe of the vaporizer and increasing back pressure on the condensate discharge side, the condensate can be quickly discharged from the vaporizer, thereby ensuring the stable operation of the equipment, guaranteeing the safe use of the natural gas system, and avoiding unnecessary economic losses.

[0005] A method for rapid discharge of condensate from an LNG ship vaporizer specifically includes the following steps:

[0006] S1, Connect a gas pipeline to the condensate deposit tube of the vaporizer, and the gas pipeline is set at a height position between the first high-level alarm line and the second high-level alarm line of the condensate deposit tube;

[0007] S2, Install a control valve on the gas pipeline and link the control valve with the liquid level sensor of the vaporizer used to detect whether the water level in the condensate deposition tube has reached the first high-level alarm line;

[0008] S3, when the water level in the condensate deposit pipe reaches the first high-level alarm line, the control valve opens, and pressurized gas at a specific pressure in the gas pipeline is introduced into the condensate deposit pipe. Under the push of the pressurized gas, the condensate in the condensate deposit pipe will be quickly discharged to the downstream pipeline.

[0009] Preferably, the diameter of the gas pipeline is DN25.

[0010] Preferably, the pressurized gas in the gas pipeline is compressed air or nitrogen.

[0011] When the pressurized gas in the gas pipeline is compressed air, the gas pipeline is connected to the compressed gas source on the LNG ship via a gas pipe.

[0012] When the pressurized gas in the gas pipeline is nitrogen, the gas pipeline is connected to the nitrogen system on the LNG ship via a gas pipe.

[0013] Preferably, the pressure of the pressurized gas is 4-5 bar.

[0014] Preferably, the gas pipeline is arranged at an angle downwards to form a certain angle with the condensate deposition pipe.

[0015] Preferably, the first high-level alarm line is set at 50%-60% of the full condensate level;

[0016] The second high-level alarm line is set at 90% of the full condensate level.

[0017] The beneficial effects of this invention are:

[0018] 1. By installing a gas pipeline on the condensate deposit pipe of the vaporizer and increasing back pressure on the condensate discharge side, the condensate can be quickly discharged from the vaporizer, thereby ensuring the stable operation of the equipment, guaranteeing the safe use of the natural gas system, and avoiding unnecessary economic losses.

[0019] 2. In this application, the pressure of the pressurized gas in the gas pipeline is set to 4-5 bar. This can create back pressure in the condensate deposition tube, thereby pushing the condensate downward and causing it to be discharged quickly. At the same time, it will not cause the condensate surface to splash back and accidentally hit the level sensor located at the second high-level alarm line, thus preventing false judgment and equipment shutdown. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the vaporizer of this application.

[0022] The meanings of the labels in the diagram are as follows:

[0023] 1 is the vaporizer, 2 is the condensate deposit pipe, 3 is the gas pipeline, and 4 is the control valve. Detailed Implementation

[0024] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] The present application will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0027] In the description of this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] In this specification, it should be understood that the directional terms such as "upper," "lower," "left," and "right" used in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0029] This invention provides a rapid method for discharging condensate from an LNG ship vaporizer, specifically including the following steps:

[0030] S1, a gas pipeline 3 is connected to the condensate deposition pipe 2 of the vaporizer 1. The gas pipeline 3 is set at a height between the first high-level alarm line and the second high-level alarm line of the condensate deposition pipe 2.

[0031] The gas pipeline 3 can be connected horizontally to the condensate deposit pipe 2, or it can be set at an angle downwards to form a certain angle with the condensate deposit pipe 2. When the gas pipeline 3 is set at an angle downwards, the discharge speed of the condensate can be further accelerated.

[0032] The vaporizer 1 is equipped with a first high-level alarm line and a second high-level alarm line for the condensate level. When the level reaches or exceeds the first high-level alarm line, the system will issue an alarm. However, when the level reaches or exceeds the second high-level alarm line, the system will stop the vaporizer 1 from operating.

[0033] To prevent excessive air intake into the condensate deposition pipe 2, which could cause liquid level backflow and lead to false detection by the level sensor at the second high-level alarm line, thus halting equipment operation, the diameter of the gas pipeline 3 should not be too large. In this embodiment, the gas pipeline 3 is a galvanized steel pipe with a diameter of DN25, and the end of the gas pipeline 3 is equipped with a flange of appropriate size. The selected flange should conform to national or international standards.

[0034] S2, a control valve 4 is installed on the gas pipeline 3, and the control valve 4 is linked with the liquid level sensor of the vaporizer 1, which is used to detect whether the water level in the condensate deposition tube 2 has reached the first high-level alarm line.

[0035] When the level sensor at the first high alarm line detects that the liquid level in the condensate deposit pipe 2 has reached or exceeded the first high alarm line, it will transmit the detection signal to the IAS system of the LNG ship. The IAS system will then send an opening command to the control valve 4, thereby allowing pressurized gas to enter the condensate deposit pipe 2 through the gas pipeline.

[0036] The control valve 4 can be a pneumatic valve or an electric valve with pressure reduction function and linear control.

[0037] S3, when the water level in the condensate deposit pipe 2 reaches the first high-level alarm line, the control valve 4 opens, and pressurized gas at a specific pressure in the gas pipeline is introduced into the condensate deposit pipe 2, forming back pressure upstream of the condensate. Driven by the pressurized gas, the condensate in the condensate deposit pipe 2 will be quickly discharged to the downstream pipeline.

[0038] In this embodiment, the pressurized gas in gas pipeline 3 can be compressed air or nitrogen.

[0039] When the pressurized gas in gas pipeline 3 is compressed air, gas pipeline 3 is connected to the compressed gas source on the LNG ship through a gas pipe.

[0040] When the pressurized gas in gas pipeline 3 is nitrogen, gas pipeline 3 is connected to the nitrogen system on the LNG ship via a gas pipe.

[0041] The pressurized gas pressure should not be designed to be too high. Excessive pressure will blow up the condensate level, potentially causing it to accidentally hit the level sensor at the second high-level alarm line, resulting in equipment shutdown. Conversely, the pressurized gas pressure should not be designed to be too low. Insufficient pressure will prevent the condensate from being pushed, causing the condensate level to rise continuously. When the condensate level reaches the second high-level alarm line, it will also cause the equipment to stop. Therefore, in this embodiment, the pressurized gas pressure is set at 4-5 bar.

[0042] Preferably, in this embodiment, the first high-level alarm line is set at 50% of the full condensate level, and should not exceed 60% of the full condensate level. Time should be allowed for relevant sensors and valves to provide feedback and response, so as to ensure the normal operation of the vaporizer.

[0043] The second high-level alarm line is set at 90% of the full condensate level, leaving a 10% clearance to handle condensate discharge in a timely manner and prevent condensate backflow.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid discharge of condensate from an LNG ship vaporizer, characterized in that, Specifically, the following steps are included: S1, Connect a gas pipeline to the condensate deposit tube of the vaporizer, and the gas pipeline is set at a height position between the first high-level alarm line and the second high-level alarm line of the condensate deposit tube; S2, Install a control valve on the gas pipeline and link the control valve with the liquid level sensor of the vaporizer used to detect whether the water level in the condensate deposition tube has reached the first high-level alarm line; S3, when the water level in the condensate deposit pipe reaches the first high-level alarm line, the control valve opens, and pressurized gas with a pressure of 4-5 bar in the gas pipeline is introduced into the condensate deposit pipe. Under the push of the pressurized gas, the condensate in the condensate deposit pipe will be quickly discharged to the downstream pipeline. The diameter of the gas pipeline is DN25.

2. The rapid discharge method for condensate from the vaporizer of an LNG ship according to claim 1, characterized in that, The pressurized gas in the gas pipeline is compressed air or nitrogen. When the pressurized gas in the gas pipeline is compressed air, the gas pipeline is connected to the compressed gas source on the LNG ship via a gas pipe. When the pressurized gas in the gas pipeline is nitrogen, the gas pipeline is connected to the nitrogen system on the LNG ship via a gas pipe.

3. The rapid discharge method for condensate from the vaporizer of an LNG ship according to claim 1, characterized in that, The gas pipeline is set at an angle downwards to form a certain angle with the condensate deposition pipe.

4. The rapid discharge method for condensate from the vaporizer of an LNG ship according to claim 1, characterized in that, The first high-level alarm line is set at 50%-60% of the full condensate level. The second high-level alarm line is set at 90% of the full condensate level.

Images