Improved LNG gasification cold energy utilization device

Abstract

The technical scheme of the utility model relates to an improved LNG (Liquefied Natural Gas) gasification cold energy utilization device, belonging to the technical field of liquefied natural gas gasification devices and safety and energy conservation. The system comprises an LNG storage tank, a pressure regulating pry, an air bath vaporizer, an air bath LNG inlet valve, a water bath vaporizer, a water bath LNG inlet valve, a built-in heat exchanger, a water bath LNG outlet valve, a circulating water pump, a circulating water inlet valve, a circulating water outlet valve, a circulating water return port, a public engineering return port, a circulating water pool and the like. The main innovation point of the technical scheme of the utility model is that the water bath vaporizer and the air bath vaporizer are connected in series for use, and circulating water at 25-30 DEG C in a public engineering circulating water pool is taken as a heat source of the water bath vaporizer. According to the technical scheme, the problem that the temperature of gasified LNG is too low is effectively solved, the problem that LNG gasification cold energy is wasted in vain is effectively solved, and the problem that the temperature of public engineering circulating water is lowered slowly is effectively solved; the method also has the characteristics of stable flow, energy conservation, environmental protection, safety in operation and small investment.

Description

Technical Field

[0001] This utility model belongs to the field of liquefied natural gas (LNG) vaporization equipment and safety and energy-saving technology, and specifically relates to an improved LNG vaporization cold energy utilization device. Background Technology

[0002] LNG is short for liquefied natural gas. The critical temperature between LNG gas and liquid under normal pressure is -162℃. LNG is a clean and efficient energy source. It is stored in dedicated LNG storage tanks by manufacturers and, after being vaporized, is transported in gaseous form to gas-fired boilers for use as fuel.

[0003] The LNG vaporization process is as follows: First, LNG at -162°C is heated to approximately -130°C, reaching a gas-liquid equilibrium state. Then, the liquid LNG at approximately -130°C vaporizes into a gaseous state at -130°C. Next, the gaseous natural gas at -130°C is heated to room temperature. Each of these steps is an endothermic process, with each kilogram of LNG absorbing 122 kilocalories of heat. During the LNG vaporization process, the surfaces of pipelines, vaporizers, and pressure regulating devices accumulate significant amounts of ice and frost. Ice and frost are also forms of cold energy release; therefore, a large amount of the cold energy carried by the LNG material is wasted during this process.

[0004] On the other hand, due to the low ambient temperature in winter, the vaporization effect of LNG using air bath vaporizers is poor, with the post-vaporization temperature being 10°C lower than the ambient temperature. From November to February, the post-vaporization temperature often remains below zero, leading to severe frost and ice formation on the pipelines. Low gas temperature increases boiler steam consumption and steam costs; furthermore, since the gas pipelines are made of carbon steel, there is a safety risk of material brittleness when used in low-temperature environments. Therefore, to ensure the normal operation of the gas boiler, it is necessary to use electric auxiliary heating to raise the temperature of some LNG vaporization pipelines under low-temperature conditions. This results in a significant waste of energy, both in terms of the waste of cold energy generated during LNG vaporization and the need for electric auxiliary heating on some low-temperature gas pipelines. Therefore, it is essential to improve the LNG vaporization device to effectively recover and utilize the cold energy generated during LNG vaporization. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a reasonable improvement to the LNG vaporization device. The main innovation lies in connecting a water bath vaporizer and an air bath vaporizer in series. The circulating water (25-30°C) from the utility's circulating water tank serves as the heat source for the water bath vaporizer, assisting in the vaporization of LNG. The cold energy released during vaporization cools the circulating water passing through the water bath vaporizer before returning to the utility's circulating water tank. This effectively utilizes the cold energy generated by LNG vaporization to significantly cool the utility's circulating water system. This invention effectively solves the problems of excessively low LNG temperature after vaporization, the waste of LNG vaporization cold energy, and slow cooling of the utility's circulating water. Furthermore, it features a stable process, energy efficiency, environmental friendliness, safe operation, and low investment.

[0006] The present invention discloses an improved LNG vaporization cold energy utilization device, comprising: an LNG storage tank, a pressure regulating skid, an air bath vaporizer, an air bath LNG inlet valve, a water bath vaporizer, an LNG pipeline, a water bath LNG inlet valve, an internal heat exchanger, a water bath LNG outlet valve, a circulating water pump, a circulating water pipeline, a circulating water inlet valve, a circulating water outlet valve, a circulating water return port, a utility return port, and a circulating water pool. The water bath vaporizer is connected in series with the air bath vaporizer via a water bath LNG inlet valve and an LNG pipeline on its lower side. The air bath vaporizer is connected to the LNG storage tank via the pressure regulating skid. A water bath LNG outlet valve is connected to the upper side of the water bath vaporizer. A circulating water pump is connected to the bottom of the water bath vaporizer via a circulating water inlet valve and a circulating water pipeline. The circulating water pump is located on the lower side of the circulating water pool. The top of the water bath vaporizer is connected to the circulating water pool via a circulating water outlet valve and a circulating water pipeline.

[0007] Preferably, the improved LNG vaporization cold energy utilization device described in this utility model is characterized in that an internal heat exchanger is installed inside the water bath vaporizer, the shell side is filled with circulating water, and the shell side working pressure is 0.3 to 0.5 MPa.

[0008] Preferably, the improved LNG vaporization cold energy utilization device described in this utility model is characterized in that the internal heat exchanger is a shell-and-tube condenser with a heat exchange area of ​​50-100 m². 2 The working pressure of the tube side is 0.8 to 1.0 MPa.

[0009] Preferably, the improved LNG vaporization cold energy utilization device described in this utility model is characterized in that the circulating water pipe has a diameter of 125-150 mm and a flow rate of 30-40 m³ / h. 3 .

[0010] The improved LNG vaporization cold energy utilization device described in this utility model has the following significant benefits: 1. The parallel connection of the water bath vaporizer and the air bath vaporizer can effectively solve the problem of excessively low LNG vaporization temperature, which not only saves a large amount of electricity consumed by electric auxiliary heating, but also greatly benefits the safe operation of the gas boiler; 2. The large flow rate of circulating water through the water bath vaporizer can promptly remove the cold energy generated by LNG vaporization, which is very beneficial for the temperature regulation of the circulating water pool in public works; 3. It also features stable process, safe operation, and low investment. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0012] Figure 1 This is a schematic diagram of the process and structure of an improved LNG gasification cold energy utilization device according to an embodiment of the present invention.

[0013] Figure 1 In the middle: LNG storage tank 01, pressure regulating skid 02, air bath vaporizer 03, air bath LNG inlet valve 04, water bath vaporizer 05, water bath LNG inlet valve 06, internal heat exchanger 07, water bath LNG outlet valve 08, connection direction to gas boiler 12, circulating water pump 09, circulating water inlet valve 10, circulating water outlet valve 11, circulating water return port 13, utility return port 14, circulating water pool 15, LNG pipeline 16, circulating water pipeline 17. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the following description is provided in conjunction with... Figure 1 The specific embodiments of this implementation will be further described.

[0015] This specific embodiment describes an improved LNG vaporization cold energy utilization device, which includes: an LNG storage tank 01, a pressure regulating skid 02, an air bath vaporizer 03, an air bath LNG inlet valve 04, a water bath vaporizer 05, a water bath LNG inlet valve 06, an internal heat exchanger 07, a water bath LNG outlet valve 08, a connection to a gas boiler 12, a circulating water pump 09, a circulating water inlet valve 10, a circulating water outlet valve 11, a circulating water return port 13, a utility return port 14, a circulating water pool 15, an LNG pipeline 16, and a circulating water pipeline 17.

[0016] The improved LNG vaporization cold energy utilization device described in this specific embodiment is characterized in that the water bath vaporizer 05 is connected in series with the air bath vaporizer 03 via the water bath LNG inlet valve 06 and LNG pipeline 16 on the lower side. The air bath vaporizer 03 is connected to the LNG storage tank 01 via the pressure regulating skid 02. The upper side of the water bath vaporizer 05 is connected to the water bath LNG outlet valve 08 and connected to the gas boiler direction 12 via the LNG pipeline. The bottom of the water bath vaporizer 05 is connected to the circulating water pump 09 via the circulating water inlet valve 10 and circulating water pipeline 17. The circulating water pump 09 is located on the lower side of the circulating water pool 15. The top of the water bath vaporizer 05 is connected to the circulating water pool 15 via the circulating water outlet valve 11 and circulating water pipeline 17.

[0017] Furthermore, the working process of the improved LNG vaporization cold energy utilization device described in this specific embodiment can be described as follows: When the water bath vaporizer 05 is started for the first time, the circulating water inlet valve 10 and the circulating water outlet valve 11 on the circulating water pipeline 17 are opened first, and the circulating water pump 09 is turned on. Then, the water bath LNG inlet valve 06 is opened according to the operating procedure, so that the LNG that has been initially vaporized by the air bath vaporizer 03 enters the internal heat exchanger 07 installed inside the water bath vaporizer 05. After heat exchange with the 25-30°C circulating water, the vaporized LNG flows through the water bath LNG outlet valve 08 and the LNG pipeline 16 to the direction of connecting to the gas boiler. After being cooled by the circulating water that has exchanged heat with the low-temperature LNG, it flows into the circulating water pool 15 through the circulating water return port 14. This cycle is repeated, so that the circulating water can vaporize the LNG and provide auxiliary heat, and the circulating water that carries away most of the cold energy of the LNG can effectively cool the circulating water pool of the utility project.

[0018] Furthermore, the improved LNG vaporization cold energy utilization device described in this specific embodiment is characterized in that an internal heat exchanger is installed inside the water bath vaporizer, the shell side is filled with circulating water, and the shell side working pressure is 0.3 to 0.5 MPa.

[0019] Furthermore, the improved LNG vaporization cold energy utilization device described in this specific embodiment is characterized in that the internal heat exchanger is a shell-and-tube condenser with a heat exchange area of ​​50-100 m². 2 The working pressure of the tube side is 0.8 to 1.0 MPa.

[0020] Furthermore, in this specific embodiment of the improved LNG vaporization cold energy utilization device, the circulating water pipe has a diameter of 125-150 mm and a flow rate of 30-40 m³ / h. 3 .

[0021] The improved LNG vaporization cold energy utilization device described in this utility model has the following significant benefits: 1. The parallel connection of the water bath vaporizer and the air bath vaporizer can effectively solve the problem of excessively low LNG vaporization temperature, which not only saves a large amount of electricity consumed by electric auxiliary heating, but also greatly benefits the safe operation of the gas boiler; 2. The large flow rate of circulating water through the water bath vaporizer can promptly remove the cold energy generated by LNG vaporization, which is very beneficial for the temperature regulation of the circulating water pool in public works; 3. It also features stable process, safe operation, and low investment.

[0022] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model shall be included within the protection scope of this utility model. The protection scope of this utility model shall conform to the widest range consistent with the principles and novel features described herein.

Claims

1. An improved LNG gasification cold energy utilization device, comprising: LNG storage tank, pressure regulating pry, air bath gasifier, air bath LNG import valve, water bath gasifier, LNG pipeline, water bath LNG import valve, built-in heat exchanger, water bath LNG export valve, circulating water pump, circulating water pipeline, circulating water import valve, circulating water export valve, circulating water return port, utility return port, circulating water pool, characterized in that the water bath gasifier is connected with the air bath gasifier in series through the water bath LNG import valve and the LNG pipeline on the lower side, the air bath gasifier is connected with the LNG storage tank through the pressure regulating pry, the water bath gasifier is connected with the water bath LNG export valve on the upper side, the water bath gasifier is connected with the circulating water pump through the circulating water import valve and the circulating water pipeline at the bottom, the circulating water pump is arranged on the lower side of the circulating water pool, and the water bath gasifier is connected with the circulating water pool through the circulating water export valve and the circulating water pipeline at the top.

2. The improved LNG gasification cold energy utilization device according to claim 1, characterized in that, The water bath gasifier is internally provided with the built-in heat exchanger, the shell side is circulated with water, and the working pressure of the shell side is 0.3-0.5 MPa.

3. The improved LNG gasification cold energy utilization device according to claim 1, characterized in that, The built-in heat exchanger is a column tube condenser, the heat exchange area is 50-100m 2 , and the working pressure of the tube is 0.8-1.0 MPa.

4. The improved LNG gasification cold energy utilization device according to claim 1, characterized in that, The circulating water pipeline diameter is 125-150 mm, and the hourly flow is 30-40 m 3 .

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