Liquid carbon dioxide storage tank vent gas recovery system

Abstract

The utility model discloses a kind of liquid carbon dioxide storage tank vent gas recovery systems, including liquid carbon dioxide storage tank, with the liquid carbon dioxide storage tank communication's discharge pipeline and the pressure relief valve being set on discharge pipeline, the condenser is additionally provided on the discharge pipeline;The impurity discharge pipe is connected with the pressure relief valve, for discharging unliquefied impurity gas;The position of the condenser is higher than the liquid level height of the liquid carbon dioxide storage tank, ensure that liquefied liquid carbon dioxide is self-flowed back into the liquid carbon dioxide storage tank by gravity;The utility model increases a condenser on the discharge pipeline after the carbon dioxide evaporation of storage tank, and the carbon dioxide condensation liquefaction liquid carbon dioxide after evaporation is carried out by condenser, nitrogen in carbon dioxide evaporation gas continues to discharge after pressure relief after pressure relief valve;Not only can the recovery of carbon dioxide vent gas be realized, but also the purity of carbon dioxide can be improved.

Description

Technical Field

[0001] This utility model relates to the field of carbon dioxide recovery technology, specifically to a liquid carbon dioxide storage tank venting and recovery system. Background Technology

[0002] Currently, liquid carbon dioxide is stored in cryogenic liquid storage tanks. Due to long-term storage, it will absorb heat and vaporize. After vaporization, the pressure inside the storage tank increases. When the maximum working pressure of the storage tank is reached, it must be vented to release the pressure. If the pressure is not released in time, it will damage the equipment. After venting, the carbon dioxide is released into the air, resulting in waste. In order to change this situation, this application proposes a liquid carbon dioxide storage tank venting air recovery system. Utility Model Content

[0003] The purpose of this invention is to provide a liquid carbon dioxide storage tank venting and recovery system to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a liquid carbon dioxide storage tank venting and recovery system, comprising a liquid carbon dioxide storage tank, a discharge pipeline connected to the liquid carbon dioxide storage tank, and a pressure relief valve installed on the discharge pipeline. A condenser is added to the discharge pipeline, and the inlet end of the condenser is connected to the gas outlet of the liquid carbon dioxide storage tank for receiving evaporated gas; the outlet end of the condenser is divided into a liquefaction reflux pipe and an impurity discharge pipe.

[0005] The liquefaction return pipe is connected to the liquid carbon dioxide storage tank and is used to transport the liquid carbon dioxide liquefied by the condenser back to the liquid carbon dioxide storage tank.

[0006] The impurity discharge pipe is connected to the pressure relief valve and is used to discharge unliquefied impurity gas;

[0007] The condenser is positioned above the liquid level in the liquid carbon dioxide storage tank, ensuring that the liquefied liquid carbon dioxide flows back into the liquid carbon dioxide storage tank by gravity.

[0008] The height difference between the condenser and the liquid carbon dioxide storage tank is 0.5-2 meters.

[0009] The impurity discharge pipe is equipped with a gas-liquid separator, which is used to separate liquefied liquid carbon dioxide.

[0010] The condenser is a shell-and-tube heat exchanger, and the refrigeration temperature is controlled within the range of -40°C to -32°C.

[0011] The condenser uses R507 refrigerant.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] To avoid carbon dioxide waste, this invention adds a condenser to the discharge pipeline after carbon dioxide evaporation in the storage tank. The condenser condenses and liquefies the evaporated carbon dioxide back into liquid carbon dioxide, while the nitrogen in the evaporated carbon dioxide gas continues to be discharged after being depressurized by a pressure relief valve. The liquefied liquid carbon dioxide flows back into the liquid carbon dioxide storage tank (the height of the condenser is higher than that of the liquid carbon dioxide storage tank, ensuring that the liquefied liquid carbon dioxide can flow back into the carbon dioxide storage tank according to the height difference). Moreover, the nitrogen in the evaporated carbon dioxide gas is not liquefied, which not only realizes the recovery of carbon dioxide vented gas, but also improves the purity of carbon dioxide. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the venting structure of a liquid carbon dioxide storage tank in the background art;

[0015] Figure 2 This is a schematic diagram of the improved liquid carbon dioxide storage tank venting structure of this utility model. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0017] For existing technology 1, such as Figure 1 As shown, the liquid carbon dioxide purified by the purification tower flows from the liquid carbon dioxide inlet end into the liquid carbon dioxide storage tank for storage. Some of the liquid carbon dioxide in the liquid carbon dioxide storage tank will absorb heat and evaporate. After evaporation, the carbon dioxide is discharged from the gas carbon dioxide outlet end after being depressurized by the pressure relief valve (a small amount of nitrogen gas is discharged at the same time in the carbon dioxide), resulting in waste.

[0018] To change this situation: Please refer to... Figure 2This utility model provides a technical solution: a liquid carbon dioxide storage tank venting and recovery system, including a liquid carbon dioxide storage tank, a discharge pipeline connected to the liquid carbon dioxide storage tank, and a pressure relief valve installed on the discharge pipeline. A condenser is added to the discharge pipeline. The inlet end of the condenser is connected to the gas outlet of the liquid carbon dioxide storage tank to receive evaporated gas. The outlet end of the condenser is divided into a liquefaction return pipe and an impurity discharge pipe. Refrigerant enters the condenser through the refrigerant inlet end, and the refrigerant after heat exchange flows out through the refrigerant outlet end. The liquefaction return pipe is connected to the liquid carbon dioxide storage tank to transport the liquefied liquid carbon dioxide from the condenser back to the liquid carbon dioxide storage tank. The impurity discharge pipe is connected to the pressure relief valve to discharge unliquefied impurity gas. The condenser is positioned higher than the liquid level of the liquid carbon dioxide storage tank to ensure that the liquefied liquid carbon dioxide flows back to the liquid carbon dioxide storage tank by gravity.

[0019] To avoid carbon dioxide waste, a condenser is added to the discharge pipeline after the carbon dioxide evaporates from the storage tank. The condenser condenses and liquefies the evaporated carbon dioxide back into liquid carbon dioxide. The nitrogen in the evaporated carbon dioxide gas continues to be discharged after being depressurized by the pressure relief valve. The liquefied liquid carbon dioxide flows back into the liquid carbon dioxide storage tank (the height of the condenser is higher than that of the liquid carbon dioxide storage tank to ensure that the liquefied liquid carbon dioxide can flow back into the carbon dioxide storage tank according to the height difference). The nitrogen in the evaporated carbon dioxide gas is not liquefied. This not only realizes the recovery of carbon dioxide vent gas, but also improves the purity of carbon dioxide.

[0020] The height difference between the condenser and the liquid carbon dioxide storage tank is 0.5-2 meters, ensuring that the liquefied liquid carbon dioxide can flow back into the carbon dioxide storage tank according to the height difference.

[0021] The impurity discharge pipe is equipped with a gas-liquid separator, which is used to separate the liquefied liquid carbon dioxide. When the impurity discharge pipe discharges impurity gas (nitrogen), it can separate the nitrogen from the liquid carbon dioxide, thus preventing the nitrogen from carrying liquid carbon dioxide.

[0022] The condenser is a shell-and-tube heat exchanger with a cooling temperature controlled within the range of -40°C to -32°C. It can liquefy the evaporated carbon dioxide gas back into liquid carbon dioxide.

[0023] The condenser uses R507 refrigerant, which can effectively liquefy the evaporated carbon dioxide gas back into liquid carbon dioxide.

[0024] Working principle: During use, the purified liquid carbon dioxide flows from the inlet end of the purification tower into the liquid carbon dioxide storage tank. Some of the liquid carbon dioxide in the storage tank will absorb heat and evaporate. The evaporated carbon dioxide is discharged through the discharge pipe and flows to the condenser. The condenser condenses and liquefies the evaporated carbon dioxide back into liquid carbon dioxide. The nitrogen in the evaporated carbon dioxide gas continues to be discharged after being depressurized by the pressure relief valve. The liquefied liquid carbon dioxide flows back into the liquid carbon dioxide storage tank (the height of the condenser is higher than that of the liquid carbon dioxide storage tank to ensure that the liquefied liquid carbon dioxide can flow back into the carbon dioxide storage tank according to the height difference). The nitrogen in the evaporated carbon dioxide gas is not liquefied. This not only realizes the recovery of carbon dioxide vent gas, but also improves the purity of carbon dioxide.

[0025] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

Claims

1. A liquid carbon dioxide storage tank venting and recovery system, comprising a liquid carbon dioxide storage tank, a discharge pipeline connected to the liquid carbon dioxide storage tank, and a pressure relief valve installed on the discharge pipeline, characterized in that: A condenser is added to the discharge pipeline. The inlet end of the condenser is connected to the gas outlet of the liquid carbon dioxide storage tank to receive the evaporated gas. The outlet end of the condenser is divided into a liquefaction reflux pipe and an impurity discharge pipe. The liquefaction return pipe is connected to the liquid carbon dioxide storage tank and is used to transport the liquid carbon dioxide liquefied by the condenser back to the liquid carbon dioxide storage tank. The impurity discharge pipe is connected to the pressure relief valve and is used to discharge unliquefied impurity gas; The condenser is positioned above the liquid level in the liquid carbon dioxide storage tank, ensuring that the liquefied liquid carbon dioxide flows back into the liquid carbon dioxide storage tank by gravity.

2. The liquid carbon dioxide storage tank venting and recovery system according to claim 1, characterized in that: The height difference between the condenser and the liquid carbon dioxide storage tank is 0.5-2 meters.

3. The liquid carbon dioxide storage tank venting and recovery system according to claim 1, characterized in that: The impurity discharge pipe is equipped with a gas-liquid separator, which is used to separate liquefied liquid carbon dioxide.

4. The liquid carbon dioxide storage tank venting and recovery system according to claim 1, characterized in that: The condenser is a shell-and-tube heat exchanger, and the refrigeration temperature is controlled within the range of -40°C to -32°C.

5. The liquid carbon dioxide storage tank venting and recovery system according to claim 1, characterized in that: The condenser uses R507 refrigerant.

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