A LNG heat exchanger test system

Abstract

The present invention belongs to the technical field of compact LNG heat exchanger testing, and specifically, relates to an LNG heat exchanger testing system, including a gasification unit and a heat exchange unit. The gasification unit includes an LNG storage tank, an LNG booster pump, an LNG vaporizer and a heater connected by pipelines, an exhaust pipe is provided on the LNG storage tank, a first control valve is provided on the exhaust pipe, a first flowmeter is provided between the LNG booster pump and the LNG vaporizer, and a second control valve is provided between the LNG vaporizer and the heater. The heat exchange unit includes a propane buffer tank, a propane pump and a propane vaporizer connected by pipelines, the propane buffer tank and the propane vaporizer are respectively connected to the LNG vaporizer, a third control valve and a second flowmeter are provided between the propane pump and the propane vaporizer, and a water supply pipeline and a return water pipeline are also provided on the propane vaporizer, wherein a fourth control valve and a third flowmeter are provided on the water supply pipeline. The present invention has high test accuracy and low test cost.

Description

Technical Field

[0001] The invention belongs to the technical field of compact LNG heat exchanger testing, and in particular relates to an LNG heat exchanger testing system. Background Art

[0002] In recent years, as the proportion of clean energy LNG (liquid natural gas) usage increases year by year, countries around the world are scrambling to seize the LNG market and vigorously building LNG receiving stations and floating LNG storage and regasification units to meet the supply needs of their own LNG markets. One of the core technologies in LNG receiving stations and floating LNG storage and regasification units is the LNG vaporizer. The LNG vaporizers in LNG receiving stations are mainly divided into open-frame vaporizers, submerged combustion vaporizers and intermediate medium vaporizers. The LNG vaporizers in floating LNG storage and regasification units are mainly divided into shell and tube vaporizers and printed circuit board heat exchangers. Due to the advantages of light weight, small size and no leakage, printed circuit board heat exchangers have been widely used in floating LNG storage and regasification units in recent years. However, the core technology of printed circuit board heat exchangers has been controlled by foreign companies and is expensive in China.

[0003] In order to break the monopoly, many domestic companies and research institutions have conducted cooperative research and trial-produced a compact LNG heat exchanger prototype, which is manufactured using 3D printing technology. It has the advantages of light weight, small size, and no leakage. It can gradually replace printed circuit board heat exchangers and be used in floating LNG storage and regasification units and LNG receiving stations. In order to conduct industrial testing on the trial-produced compact LNG heat exchanger prototype, the present invention proposes a test system. Summary of the invention

[0004] In order to solve the above-mentioned defects in the prior art, the present invention provides an LNG heat exchanger testing system.

[0005] The technical solution of the present invention is as follows:

[0006] The invention provides an LNG heat exchanger testing system, comprising a gasification unit and a heat exchange unit used in conjunction with each other.

[0007] The above-mentioned gasification unit includes an LNG storage tank, an LNG boosting pump, an LNG gasifier and a heater which are connected in sequence through pipelines, wherein the above-mentioned LNG storage tank is provided with an exhaust pipe, the exhaust pipe is provided with a first control valve, the pipeline between the above-mentioned LNG boosting pump and the above-mentioned LNG gasifier is provided with a first flow meter, and the pipeline between the above-mentioned LNG gasifier and the above-mentioned heater is provided with a second control valve.

[0008] The above-mentioned heat exchange unit includes a propane buffer tank, a propane pump and a propane vaporizer which are connected in sequence through pipelines, wherein the above-mentioned propane buffer tank and the above-mentioned propane vaporizer are respectively connected to the above-mentioned LNG vaporizer, and a third control valve and a second flow meter are provided on the pipeline between the above-mentioned propane pump and the above-mentioned propane vaporizer. The above-mentioned propane vaporizer is also provided with a water supply pipeline and a return water pipeline, wherein the water supply pipeline is provided with a fourth control valve and a third flow meter.

[0009] In the embodiment provided by the present invention, the LNG storage tank and the propane buffer tank are both provided with a pressure sensor and a liquid level sensor, wherein the pressure sensor on the LNG storage tank is used to control the first control valve, the pressure sensor on the propane buffer tank is used to control the fourth control valve and the third flowmeter, and the liquid level sensor on the propane buffer tank is used to control the third control valve.

[0010] In the embodiment provided by the present invention, the pressure sensor on the propane buffer tank is connected to the first flow meter, and the change of the LNG flow rate in the first flow meter can be used to control the pressure in the propane buffer tank.

[0011] In the embodiment provided by the present invention, pressure sensors and temperature sensors are provided on the pipelines between the LNG gasifier and the LNG boosting pump, the propane buffer tank, and the propane gasifier, and pressure sensors and temperature sensors are provided on the pipeline between the LNG and the heater.

[0012] In the embodiment provided by the present invention, the pressure sensor on the pipeline between the LNG gasifier and the heater can also be used to control the second control valve.

[0013] In the embodiment provided by the present invention, the above-mentioned LNG boosting pump is driven by a variable frequency motor.

[0014] Beneficial effects: The LNG heat exchanger testing system provided by the present invention has low cost, high accuracy, simple testing process, and can also adjust the amount of hot water entering the propane gasifier according to the amount of LNG entering the LNG gasifier, further reducing the testing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 Structural diagram of the LNG heat exchanger testing system provided by the present invention.

[0017] As shown in the figure: 1-LNG heat exchanger test system; 2-LNG storage tank; 3-LNG booster pump; 4-LNG vaporizer; 5-heater; 6-first control valve; 7-first flow meter; 8-second control valve; 9-propane buffer tank; 10-propane pump; 11-propane vaporizer; 12-third control valve; 13-second flow meter; 14-fourth control valve; 15-third flow meter; 16-variable frequency motor. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the 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 therefore cannot be understood as a limitation on the present invention.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Example:

[0023] like Figure 1 As shown, this embodiment provides an LNG heat exchanger testing system 1, including a gasification unit and a heat exchange unit used in conjunction with each other.

[0024] The above-mentioned gasification unit includes an LNG storage tank 2, an LNG boosting pump 3, an LNG gasifier 4 and a heater 5 which are connected in sequence through pipelines, wherein the above-mentioned LNG storage tank 2 is provided with an exhaust pipe, the exhaust pipe is provided with a first control valve 6, the pipeline between the above-mentioned LNG boosting pump 3 and the above-mentioned LNG gasifier 4 is provided with a first flow meter 7, and the pipeline between the above-mentioned LNG gasifier 4 and the above-mentioned heater 5 is provided with a second control valve 8.

[0025] The heat exchange unit includes a propane buffer tank 9, a propane pump 10 and a propane vaporizer 11 which are connected in sequence through pipelines, wherein the propane buffer tank 9 and the propane vaporizer 11 are respectively connected to the LNG vaporizer 4, and a third control valve 12 and a second flow meter 13 are provided on the pipeline between the propane pump 10 and the propane vaporizer 11. A water supply pipeline and a return water pipeline are also provided on the propane vaporizer 11, wherein a fourth control valve 14 and a third flow meter 15 are provided on the water supply pipeline.

[0026] Specifically, the LNG vaporizer 4 is provided with an LNG inlet, an LNG outlet, a propane inlet, and a propane outlet. The LNG inlet is connected to the LNG booster pump 3 for delivering LNG into the LNG vaporizer 4, the LNG outlet is used to deliver the gasified LNG to the external gas supply network through the heater 5, the propane inlet is connected to the propane vaporizer 11, and is used to deliver the gasified high-temperature propane into the LNG vaporizer 4 to exchange heat with the LNG therein, thereby converting the LNG into gaseous natural gas, and the propane after heat exchange flows into the propane buffer tank 9 through the propane outlet.

[0027] In this embodiment, the LNG storage tank 2 and the propane buffer tank 9 are both provided with a pressure sensor and a liquid level sensor, wherein the pressure sensor on the LNG storage tank 2 is used to control the first control valve 6, and the pressure sensor on the propane buffer tank 9 is used to control the fourth control valve 14 and the third flow meter 15, wherein the fourth control valve 14 is used to control the amount of hot water flowing into the propane vaporizer 11, and the third flow meter 15 is used to measure the flow of hot water flowing into the propane vaporizer 11. The liquid level sensor on the propane buffer tank 9 is used to control the third control valve 12.

[0028] Specifically, the pressure sensor on the LNG storage tank 2 is a pressure sensor (PC), which can be used to control the opening of the first control valve 6. The liquid level sensor on the LNG storage tank 2 is a liquid level measurement sensor (LT), which is used to measure the liquid level height in the LNG storage tank 2 and transmit the measured value to the external display screen. The pressure sensor on the propane buffer tank 9 is also a pressure sensor (PC), which is used to control the opening of the fourth control valve 14. The fourth control valve 14 can control the amount of hot water flowing into the propane vaporizer 11, and the third flowmeter 15 can be used to measure the flow rate of hot water flowing into the propane vaporizer 11. When the pressure in the propane buffer tank 9 changes, the fourth control valve 14 will adjust the flow rate of hot water in the third flowmeter 15 as the pressure changes. The liquid level sensor on the propane buffer tank 9 is a liquid level sensor (LC). When the liquid level in the propane buffer tank 9 reaches a certain height, the third control valve 12 can be opened. As the liquid level in the propane buffer tank 9 changes, the opening of the third control valve 12 also changes accordingly.

[0029] In this embodiment, the pressure sensor on the propane buffer tank 9 is connected to the first flow meter 7, which is used to measure the LNG flow rate flowing into the LNG gasifier 4, and the change in the LNG flow rate in the first flow meter 7 can be used to control the internal pressure of the propane buffer tank 9.

[0030] Similarly, when the LNG flow in the first flowmeter 7 changes, the pressure in the propane buffer tank 9 will change accordingly. At this time, the fourth control valve 14 will control the amount of hot water flowing into the propane vaporizer 11 measured by the third flowmeter 15.

[0031] In this embodiment, a pressure sensor (PT) and a temperature sensor (TT) are provided on the pipelines between the LNG gasifier 4 and the LNG boosting pump 3, the propane buffer tank 9, and the propane gasifier 11, and a pressure sensor (PC) and a temperature sensor (TT) are provided on the pipeline between the LNG and the heater 5.

[0032] In this embodiment, the pressure sensor on the pipeline between the LNG vaporizer 4 and the heater 5 can also be used to control the second control valve 8 .

[0033] Specifically, after the pressure on the pipeline between the LNG vaporizer 4 and the heater 5 reaches a certain value, the second control valve 8 is opened.

[0034] In this embodiment, the LNG boosting pump 3 is provided with a variable frequency motor 16, which is used to drive the LNG boosting pump 3. The rotation speed of the variable frequency motor 16 can be used to adjust the flow rate of the LNG boosting pump 3.

[0035] The test method of the LNG heat exchanger test system 1 provided in this embodiment is as follows:

[0036] 1) First, add a certain amount of LNG into the LNG storage tank 2 and add a certain amount of liquid propane into the propane buffer tank 9 as a heating medium;

[0037] 2) Start the LNG booster pump 3, pressurize the LNG to 13 MPa and then send it to the LNG vaporizer 4. At this time, the propane in the propane buffer tank 9 is converted into high-temperature gaseous propane through the propane vaporizer 11 under the action of the propane pump 10. The gaseous propane and the LNG in the LNG vaporizer 4 are heat-exchanged to gasify the LNG into natural gas, and the high-temperature gaseous propane is converted into a gas-liquid mixed state and enters the propane buffer tank 9, starting the next round of heat exchange cycle;

[0038] 3) The gaseous natural gas in the LNG vaporizer 4 is heated again by the heater 5 and then sent to the external gas supply network. By testing various indicators of the natural gas entering the external gas supply network, it is determined whether the various indicators meet the industrial requirements;

[0039] 4) During the test, the flow rate of the LNG boosting pump 3 is adjusted by adjusting the rotation speed of the variable frequency motor 16. When the flow rate measured by the first flow meter 7 changes, the pressure in the propane buffer tank 9 also changes, so that the fourth control valve 14 adjusts the flow rate measured by the third flow meter 15 to ensure that the amount of LNG flowing into the LNG vaporizer 4 matches the amount of high-temperature gaseous propane for heat exchange therewith, ensuring that all the LNG in the LNG vaporizer 4 is vaporized into gaseous natural gas.

[0040] The beneficial effects of the LNG heat exchanger testing system provided in this embodiment are as follows: the LNG heat exchanger testing system provided by the present invention is low in cost, high in accuracy, and has a simple testing process. It can also adjust the amount of hot water entering the propane vaporizer according to the amount of LNG entering the LNG vaporizer, further reducing the testing cost.

[0041] The above description is not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An LNG heat exchanger testing system, characterized in that: It includes a gasification unit and a heat exchange unit used in conjunction with each other; The gasification unit comprises an LNG storage tank, an LNG booster pump, an LNG gasifier and a heater which are sequentially connected through pipelines, wherein the LNG storage tank is provided with an exhaust pipe, the exhaust pipe is provided with a first control valve, the pipeline between the LNG booster pump and the LNG gasifier is provided with a first flow meter, and the pipeline between the LNG gasifier and the heater is provided with a second control valve; The heat exchange unit comprises a propane buffer tank, a propane pump and a propane vaporizer which are sequentially connected through pipelines, wherein the propane buffer tank and the propane vaporizer are respectively connected to the LNG vaporizer, a third control valve and a second flow meter are provided on the pipeline between the propane pump and the propane vaporizer, and a water supply pipeline and a return water pipeline are also provided on the propane vaporizer, wherein a fourth control valve and a third flow meter are provided on the water supply pipeline; The LNG storage tank and the propane buffer tank are both provided with a pressure sensor and a liquid level sensor, wherein the pressure sensor on the LNG storage tank is used to control the first control valve, the pressure sensor on the propane buffer tank is used to control the fourth control valve and the third flow meter, and the liquid level sensor on the propane buffer tank is used to control the third control valve; The pressure sensor on the propane buffer tank is connected to the first flow meter, and the change of the LNG flow rate in the first flow meter is used to control the pressure in the propane buffer tank; The pipelines between the LNG vaporizer and the LNG boosting pump, the propane buffer tank, and the propane vaporizer are all provided with pressure sensors and temperature sensors, while the pipeline between the LNG vaporizer and the heater is provided with a pressure sensor and a temperature sensor.

2. The LNG heat exchanger testing system according to claim 1, characterized in that: The pressure sensor on the pipeline between the LNG vaporizer and the heater is also used to control the second control valve.

3. The LNG heat exchanger testing system according to claim 1, characterized in that: The LNG boosting pump is driven by a variable frequency motor.

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