RU39928U1 - INSTALLATION OF COLLECTION AND DISPOSAL OF VAPORS OF HYDROCARBONS FROM RESERVOIRS OF OIL PRODUCTS - Google Patents

Abstract

The utility model relates to the design of installations intended for the storage of petroleum products used in the petroleum, petrochemical and oil refining industries, in particular during the storage and retail sale of gasoline in urban gas stations. An installation is proposed for collecting and utilizing hydrocarbon vapors from oil product tanks, containing a tank connected to each other by a piping system in the form of a tank (1) for storing an oil product, including a cavity with liquid oil and a gas cavity with a vapor-air mixture, a low-pressure compressor (2) to ensure the selection of vapor-air mixture from the tank (1), the movement of the vapor-air mixture through the evaporator-heat exchanger (4) and the supply of condensate to the tank (1). As well as a receiver-steam separator (3) for partial condensation of the vapor of the air-vapor mixture immediately after taking it from the tank (1), a refrigeration machine (5) for cooling the steam-air mixture in the evaporator-heat exchanger (4), into which the remaining steam-air mixture comes from the receiver- a steam separator (3), a throttle (6 ′) through which a cooled vapor-air mixture from the evaporator-heat exchanger (4) is fed back to the tank (1) through a heat-insulated pipe. As well as a throttle (6), through which oil condensed in the evaporator-heat exchanger (4) and receiver-steam separator (3) also flows back to the tank (1).

Description

The utility model relates to the design of facilities for storing petroleum products used in the petroleum, petrochemical and oil refining industries, as well as other industries related to the storage of volatile petroleum products, for example, during storage and retail sale of gasolines in urban gas stations.

The proposed device can be used where storage and distribution systems for petroleum products are used: gas stations, oil depots, oil refineries, motor transport enterprises, in the territory of which refueling is carried out, etc.

The objective is to reduce losses of petroleum products due to the capture of hydrocarbons from the vapor-air mixture emitted into the atmosphere from underground or ground tanks containing hydrocarbon liquids (oil, gasoline, kerosene, etc.) by condensation of hydrocarbon vapors, which leads to an improvement in environmental and fire conditions in the area where the tanks are located (above ground, underground) with any cross-sectional shape with the oil products stored in them. The latter is especially important for megacities, such as Moscow, with a high concentration of road transport and dense urban development.

A technical solution is known to reduce the loss of volatile products, according to which a vapor-air mixture (PVA) is passed through a two-stage cooling system. The first stage cools the PVA to a temperature of plus 0.5-1.5 ° C, the second to minus

1-7 ° C (US patent No. 3266262, CL 62-54). The disadvantage of this invention is that the indicated cooling temperature is insufficient for efficient (more than 50%) capture of hydrocarbons (see book N. N. Konstantinov, Combating losses from evaporation of oil and oil products, M., "Gostoptekhizdat", 1961, p. 185). In addition, the temperature of the outgoing PVA is different from the ambient temperature, which leads to freezing of the breathing valves (in the warm season) and low thermodynamic efficiency of the installation (the cost of cold for cooling the environment).

A technical solution is known for storing petroleum products with vapor recovery (AS USSR No. 1406074, class B 65 D 90/30, 1988), according to which PVA is condensed by sparging the latter through a condenser filled with refrigerated oil. Pre-cooling the PVA to 0 ° C with a return flow of cold air allows both to avoid ice plugs (when water freezes) and to reduce the energy consumption for pre-cooling (up to 0 ° C) of the PVA. The disadvantage of this method of cooling PVA is its limited capabilities, since the cold return flow of the expired air is not enough.

A technical solution is known, also aimed at storing petroleum products with vapor recovery (AS USSR No. 1406075, B 65 D 90/30, 1988), consisting in the selection of PVA from the gas space (GP) of the tank, passing it in the bubble mode through a layer of the same oil product and returning the air after bubbling back to the reservoir GP. The bubbling oil product is cooled to a temperature below the temperature of the corresponding bottom layers of the oil product and above a temperature corresponding to zero partial vapor pressure by cooling with a low-temperature refrigerant and thermostating by penetration into the soil.

However, this solution has limited application.

for tanks with a variable cross-section (cylindrical type RGS, trapezoidal), since it is impossible to use effective floating protective coatings in the indicated types of tanks. The latter circumstance is important, since when PVA is depleted in the GP, due to condensation of hydrocarbons and the return of clean air to the GP of the reservoir, the latter is saturated with hydrocarbons (additional evaporation from the surface of the liquid), which leads to an increase in the intra-reservoir pressure (reverse expiration). Despite the fact that the returned, purified air has a lower temperature than the selected mixture, this effect takes some time, since the cooling rate of the GP by the returned air, and therefore the upper layers of oil products, is lower than the rate of evaporation of the latter in space by unsaturated hydrocarbons. In this solution, a floating coating is used and therefore an arbitrarily small depletion or cooling of the GP of the reservoir is possible without compromising the safety of the oil product. Moreover, the rate of increase in the concentration of hydrocarbons is several times lower than over an unprotected surface.

Other technical solutions are also known in the art, US Pat. No. 5,469,986, 1995; US patent No. 5490873, 1996; U.S. Patent No. 5,185,486, 1993; Japan Patent No. 08-048984, 1996; RF patent No. 2050170, 1995; RF patent No. 2193001, 2002

However, all known designs of hydrocarbon vapor recovery and utilization systems from oil product tanks have a number of disadvantages associated either with the high cost and complexity of their operation, or with insufficient efficiency and limited use.

The objective of the proposed utility model is to reduce the concentration of hydrocarbon emissions into the atmosphere to the value of the upper concentration limit of vapor explosive (for motor gasoline 5.2%), to reduce the loss of oil products when

storage and delivery, utilization of hydrocarbon vapors for tanks with any cross-sectional shape in the absence of a floating pontoon.

To solve this problem, a design was developed for a unit for capturing and utilizing hydrocarbon vapors from oil product tanks, containing a tank connected to each other by a piping system in the form of a tank (1) for storing an oil product, including a cavity with liquid oil and a gas cavity with a vapor-air mixture, a low-pressure compressor ( 2) to ensure the selection of the steam-air mixture from the tank (1), the movement of the steam-air mixture through the evaporator-heat exchanger (4) and the condensate supply to the tank (1), the receiver a trap (3) for partial condensation of the vapor of the air-vapor mixture immediately after it is taken from the tank (1), a refrigeration machine (5) for cooling the steam-air mixture in the evaporator-heat exchanger (4), into which the remaining steam-air mixture comes from the receiver-steam separator (3) , a choke (6 ′) through which the cooled vapor-air mixture from the evaporator-heat exchanger (4) is fed back to the tank (1) through a heat-insulated pipe, and also a choke (6) through which it is condensed in the evaporator-heat exchanger (4) and the receiver-steam trap Ithel (3) oil is also fed back into the container (1).

In this case, to reduce the required cooling capacity of the chiller (5), an additional heat exchanger (7) can be used, cooled by means of soil cold, installed between the receiver-steam separator (3) and the evaporator-heat exchanger (4).

To increase the degree of condensation of hydrocarbons and reduce the amount of freezing moisture in the heat exchanger, the evaporator-heat exchanger (4) can be made of two stages, the first of which (4 ′) serves to cool the vapor-air mixture to a temperature of +1 to + 0.5 ° С and the second (4 ′ ′) - to the required low temperature, in

in particular from -80 to -40 ° C, while the first stage (4 ′) is provided with a means of water drainage (8).

The essence of the proposed utility model is illustrated in the presented figures 1-3:

Figure 1 - image of the main block diagram of the installation;

Figure 2 - image of a block diagram of the installation with an additional heat exchanger buried in the ground;

Figure 3 - image of a block diagram of the installation with an additional heat exchanger buried in the ground and a separate two-stage main evaporator-heat exchanger 4 ′, 4 ″;

Designations in figure 1-3:

1- underground reservoir (capacity);

2- low pressure compressor (up to 5 atm.);

3- receiver-steam separator;

4- evaporator-heat exchanger;

4′- first stage evaporator;

4 ′ ′ - second stage evaporator;

5- refrigeration machine (XM);

6,6′-throttles (throttle valves);

7 - additional heat exchanger;

8- means of water drainage.

Figure 1 shows a diagram of the proposed installation. Installation works as follows. In storage mode, the PVA is selected by compressor 2, fed to a buried receiver-steam separator 3, after partial condensation, the vapors pass through the evaporator-heat exchanger 4, are cooled, and fed through a thermally insulated pipeline through the inductor 6 ′ to the gas compressor. After throttling, the return steam acquires a lower temperature than when it is cooled in XM 5, which leads to more intense cooling of the HP, and, consequently, a decrease in the concentration of vapor in it. Thus, in the tank (s) 1

a lower level of equilibrium vapor concentration is maintained, and therefore the energy costs of condensing the latter are reduced. The oil product condensed in the evaporator-heat exchanger 4 is fed back to the tank 1 through the inductor 6. The PVA moves through the heat exchanger and the condensate is supplied to the tank due to the pressure created by the compressor 2. The PVA in the evaporator-heat exchanger 4 is cooled by a refrigeration machine 5.

Figure 2-3 shows a diagram of the proposed modifications of the installation. Since the heat of ХМ 5, especially during “big breaths”, is spent on cooling the PVA from the ambient temperature to the condensation temperature of the oil product, it is advisable to use soil cold to pre-cool the PVA (to a temperature of + 10 ° С to + 7 ° С). An additional heat exchanger is used for this purpose. 7. Thermostating by submerging an intermediate heat exchanger into the ground ensures rational use of cold of a low-temperature refrigerant from the point of view of energy saving, minimizing the loss of cold to the environment, and also for hotter regions (Central Asia) the difference in soil temperature and The environment can be quite substantial.

The separation of the evaporator-heat exchanger 4 into two: 4 '(with a water drain 8) and 4 ″ allows you to avoid ice plugs in the passage of the PVA.

The refrigeration machine 5 is used for cooling-condensation of hydrocarbons in the composition of the PVA. The connection of XM 5 with a throttle, and the latter with a tank, is carried out in order to avoid the dispersion of cold into the environment by a thermally insulated pipeline.

The following specific elements can be used to create the proposed installation:

Reservoirs (tanks) for storing petroleum products manufactured by Uraltechnostroy-Tuimazykhimmash OJSC, Republic of Bashkortostan at 10, 25, 50,

75, 100 m ³ or commercially available State Unitary Enterprise oil depot ″ Krasny Yar ″, Novosibirsk Region, tanks of the type RGS / RGSP, EP, etc. Receiver-steam separator manufactured by JSC "Ostrov", Mytishchi. Compressor of low pressure 2GU0.5-1 / 11-16C manufactured by ZAO Energomash. Evaporator-heat exchanger up to + 1 ° С produced by Uraltechnostroy-Tuimazykhimmash OJSC, Republic of Bashkortostan or Gazholodtekhnika CJSC, Moscow. The refrigerating machine produced by JSC “Ostrov”, Mytischi or the company “Nord”, Moscow. Throttle (throttle valve) 6MA-MM-VI (for liquid line), SS-4RS6 (for gas mixture line) manufactured by SWAGELOK. Evaporator-heat exchanger up to -40 ° C manufactured by Uraltechnostroy-Tuimazykhimmash OJSC, Republic of Bashkortostan or Gazholodtekhnika CJSC, Moscow.

Using the proposed installation can not only effectively reduce the concentration of hydrocarbons emitted into the atmosphere and the loss of oil products during storage and delivery. But also to utilize hydrocarbon vapors in tanks with any cross-sectional shape, and also provides ease of readjustment of existing installations, ease of maintenance and repair.

Claims (3)

1. Installation for capturing and utilizing hydrocarbon vapors from oil product tanks, containing a tank interconnected by a piping system in the form of a tank (1) for storing a petroleum product, including a cavity with liquid petroleum product and a gas cavity with a vapor-air mixture, a low pressure compressor (2) to ensure selection the steam-air mixture from the tank (1), the movement of the steam-air mixture through the evaporator-heat exchanger (4) and the condensate supply to the tank (1), the receiver-steam separator (3) for partial condensation of steam immediately after taking it from the tank (1), a chiller (5) for cooling the steam-air mixture in the evaporator-heat exchanger (4), into which the remaining steam-air mixture comes from the receiver-steam separator (3), the throttle (6 ') through which through a heat-insulated pipeline, the cooled vapor-air mixture from the evaporator-heat exchanger (4) is fed back to the tank (1), as well as a choke (6), through which the oil condensed in the evaporator-heat exchanger (4) and the receiver-steam separator (3) also goes back to capacity (1). 2. Installation according to claim 1, characterized in that to reduce the required cooling capacity of the chiller (5), an additional heat exchanger (7) is used, cooled by means of soil cold, installed between the receiver-steam separator (3) and the evaporator-heat exchanger (4). 3. Installation according to claim 2, characterized in that in order to increase the degree of condensation of hydrocarbons and reduce the amount of freezing moisture in the heat exchangers, the evaporator-heat exchanger (4) is made of two stages, the first of which (4 ′) serves to cool the vapor-air mixture to a temperature from 1 to 0.5 ° C, and the second (4 ′ ′) - to the required low temperature, in particular from - (80) to - (40) ° C, while the first stage (4 ′) provides a means of water drainage (8).