RU2536216C1 - Method of providing fire explosion and environmental safety during operation of tank farms for storage of crude oil and petroleum products - Google Patents

Abstract

FIELD: fire safety.

SUBSTANCE: method of providing of fire explosion and environmental safety in operation of tank farms for storage of crude oil and petroleum products is proposed, comprising mixing part of the crude oil and/or petroleum products with a mixture of nitrogen and petroleum vapour coming through gas surge from the tanks, compression of the resulting vapour-liquid mixture with volumetric pump and its accumulation in the receiver when filling the tanks or during storage of crude oil and petroleum products during the growth of the pressure in the tanks, feeding under its own pressure of the accumulated mixture of nitrogen and petroleum vapour through gas surge to the tanks when emptying the tanks or when storage of oil and oil products when the pressure drop in the tanks, the additional supply to the tanks of nitrogen produced by the device of reproduction of inert medium, with the lack of accumulated mixture of petroleum vapour and nitrogen to fill the releasing space of the tanks, and also supply under its own pressure of the mixture of crude oil and/or petroleum products with the absorbed petroleum vapour from the receiver to the tanks as they are accumulated.

EFFECT: improvement of method.

2 dwg

Description

The invention relates to methods for ensuring fire safety during the operation of tank farms for storing oil and oil products, as well as other flammable and combustible liquids, and may find application in the oil and gas, oil refining and petrochemical industries and other sectors of the national economy.

Known fire safety system for the operation of tank farms for storing oil and oil products [RF Patent No. 2247586, publ. 03/10/2005, IPC A62C 3/06], the application of which is based on a method that involves filling the reservoir fuel space, which is isolated from the surface of the stored oil and / or oil products with a floating roof, with an inert gas from the gas tank through a common supply pipe system and when emptying the tanks, compressor, and when filling the tanks - pumping the compressor with excess gas from the tanks into the gas tank.

The main disadvantage of this method is the complexity, high cost and high material consumption of the equipment used, including floating roofs in each of the tanks, as well as a gas storage tank for inert gas, with a volume equal to the total volume of the tanks.

The closest analogue of the invention, adopted as a prototype, is a combined complex for ensuring the explosion and fire safety of tank farms and oil and / or oil product storage facilities, providing isolation of the fuel space of the tanks from the atmosphere, complete explosion safety of the tank and prevention of environmental pollution [RF Patent No. 2372955, publ. November 20, 2009, IPC A62C 3/06, B67D 5/04], the operation of which uses a method that involves compressing a mixture of nitrogen and oil vapor with an acceptable concentration of oxygen coming from reservoirs through a gas equalization system in a tank filling mode, and cooling them in the refrigerator-condenser with condensation of part of the vapor of oil products and their accumulation in the receiver. In the mode of emptying the tanks, the mixture of oil vapor and nitrogen accumulated in the receiver is supplied to the tanks under its own pressure through the gas equalization system, and if there is a lack of the mixture of oil vapor and nitrogen accumulated in the receiver, nitrogen is additionally supplied from the nitrogen receiver to be filled to fill the empty space of the tanks if necessary, using an inert medium reproduction device. Condensed vapors of petroleum products are periodically transferred from the receiver to the tanks.

The disadvantage of this method is the high energy consumption for the compressor to compress a mixture of nitrogen and oil vapor in the reservoir filling mode due to heating of the compressible mixture due to the compression work and the heat of condensation from the vapor of oil products, as well as the use of expensive and metal-intensive equipment.

The objective of the invention is the reduction of energy consumption and reduction of metal equipment.

The technical result that can be obtained by implementing the method:

- reduction of energy consumption by reducing the volume of the compressible mixture of oil vapor and nitrogen due to the absorption of part of the oil vapor when mixing the mixture with part of the oil and / or oil pumped into the tanks and compressing the resulting vapor-liquid mixture with a volume pump, as well as lowering the temperature of the compress,

- cheaper and lower metal equipment by reducing pressure in the receiver.

The specified technical result is achieved by the fact that in the known method, comprising compressing a mixture of nitrogen and oil vapor coming through the gas equalization system from the tanks, and accumulating them in the receiver in the reservoir filling mode (or in storage mode with increasing pressure in the reservoirs), feeding under own the pressure of the accumulated mixture of nitrogen and oil vapor through the gas equalization system into the tanks in the mode of emptying the tanks (or in storage mode when the pressure drops in the tanks), additional the supply to the tanks of nitrogen obtained using an inert medium reproduction device, if there is a lack of an accumulated mixture of oil vapor and nitrogen to fill the vacant space of the tanks, as well as the supply of condensate oil vapor from the receiver to the tanks under their own pressure as they accumulate, a feature is that a compressible mixture of oil and nitrogen vapors is pre-mixed with part of the oil and / or oil products that are pumped into tanks or stored in tanks, and compress the floor learned vapor-liquid mixture with a volumetric pump, and as it accumulates from the receiver, a mixture of oil and / or oil products with absorbed vapors of oil products is fed into the tanks.

In the inventive method, the preliminary mixing of a compressible mixture of oil vapor and nitrogen with part of the oil and / or oil products pumped into the tanks, can significantly reduce the heating of the compressible mixture due to:

- reducing the amount of compressible gases due to the absorption of part of the vapor of oil products added part of the oil and / or oil products,

- expenditure of heat of gas compression and heat of condensation of a part of the compressible vapors for heating the added oil and / or oil products.

This allows you to reduce the pressure in the receiver or its volume, thereby reducing the metal consumption of the equipment, as well as reduce the energy consumption for compression.

Due to the limited receiver volume and the economic inexpediency of using high compression pressures of a mixture of nitrogen and oil vapor displaced from the tanks, the inventive method is preferably used for relatively small tank farms or to exclude emissions of hydrocarbon vapor into the atmosphere during small breaths of large tank parks storage, with a peak flow rate of a mixture of nitrogen and oil vapor not exceeding the volumetric flow rate of the pump (taking into account the absorption of and petroleum vapors added oil and / or mineral oils).

The method is as follows. In the reservoir filling mode (or in storage mode with increasing pressure in the reservoirs), the mixture of nitrogen and oil product vapors (I) displaced through gas equalization system 1 from the reservoirs 2 is mixed with part of the oil and / or oil products pumped (or stored - shown by the dotted line) in reservoirs (II), compress the vapor-liquid mixture (III) with a volume pump 3 and feed it into the receiver 4. In the emptying mode of the tanks (or in the storage mode when the pressure drops in the tanks), the mixture of nitrogen and oil vapor (IV) accumulated in the receiver 4, under own pressure is fed through gas equalization system 1 to tanks 2. As 4 oil and / or oil products with an absorbed part of oil vapor are accumulated in the receiver, they are also transferred to tanks 2 under their own pressure. If there is a lack of a mixture of nitrogen and oil vapor to fill the empty tanks 2 nitrogen (V), obtained, for example, using a membrane unit for producing nitrogen 6 (FIG. 1 and FIG. 2), is supplied to the receiver 4 from the nitrogen receiver 5.

The performance of the proposed method is illustrated by the following example. The tank fleet of gasoline stored in a nitrogen atmosphere, with "small breaths" of tanks, has a peak flow rate of the displaced mixture of nitrogen and gasoline vapor of 448 m ³ / h. The displaced mixture together with 5 t / h of gasoline from the bottom of one of the tanks was fed to the inlet of the volumetric pump, and the compress was then sent to a receiver with a volume of 50 m ³ , the pressure of which at the time of receiving the peak vapor flow rate was 0.5 MPa. Electricity consumption amounted to 7.9 kW. There were no emissions of hydrocarbon vapors into the atmosphere.

In the conditions of the prototype, the back pressure in the receiver was 0.76 MPa, and the energy consumption was 21.6 kW.

Thus, the above example shows that the proposed method allows the storage of oil, oil products, as well as other flammable and combustible liquids to eliminate harmful emissions into the atmosphere, to ensure a high level of explosion and environmental safety of tank farms, while reducing energy costs.

Claims (1)

A method of ensuring explosion and environmental safety during the operation of tank farms for storing oil and oil products, comprising compressing a mixture of nitrogen and oil product vapors entering through the gas equalization system from the tanks and accumulating them in the receiver in the tank filling mode (or in storage mode with increasing pressure in the tanks ), feeding under its own pressure the accumulated mixture of nitrogen and oil product vapors through the gas equalization system into the tanks in the mode of emptying the tanks (or in storage at a pressure drop in the tanks), an additional supply of nitrogen to the tanks, obtained using an inert medium reproducing device, with a lack of an accumulated mixture of oil and nitrogen vapors to fill the empty space of the tanks, as well as supply of liquefied oil vapor from the receiver to the tanks under its own pressure as they accumulate, characterized in that the compressible mixture of oil vapor and nitrogen is pre-mixed with a portion of the oil and / or oil products injected in tanks or stored in tanks, and compress the resulting vapor-liquid mixture with a volumetric pump, and as it accumulates from the receiver, a mixture of oil and / or oil products with absorbed vapors of oil products is fed into the tanks.

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