CN103550947A - Multi-stage low-temperature condensation type oil gas recovery device and using method thereof - Google Patents

Abstract

The invention provides a multi-stage low-temperature condensation type oil gas recovery device and a using method thereof, belonging to the fields of environmental protection and an energy-saving technology, and aiming at solving the problems that the oil gas recovery device in the prior art is high in cost, low in recovery efficiency, etc. The device comprises a first-stage refrigerating system, a second-stage refrigerating system and a third-stage refrigerating system, wherein a first fin condenser, a second fin condenser and a third fin condenser correspond to the first-stage refrigerating system, the second-stage refrigerating system and the third-stage refrigerating system respectively; each of the first fin condenser, the second fin condenser and the third fin condenser comprises a shell, a fin group, a refrigerant pipe and an oil outlet arranged under the shell; each fin group is formed by a plurality of fins which are sequentially connected by a pipeline and are arranged in parallel; a plurality of micropores are evenly formed in each fin; the micropores of the every two adjacent fins are arranged in a staggered way. The micropores of the every two adjacent fins are arranged in the staggered way, so that oil gas does not directly pass through the micropores of the next adjacent fin after passing through the micropores of one fin; the contact area between the oil gas and the condensers is enlarged, so that the recovery efficiency of the oil gas is improved.

Description

Multistage cryogenic condensation formula device for recovering oil and gas and using method

Technical field

The present invention relates to a kind of multistage cryogenic condensation formula device for recovering oil and gas and using method, belong to environmental protection and field of energy-saving technology.

Background technology

Along with the rise of world industry revolution spring tide, petroleum resources become one of a large amount of energy that use in the world today.Oil gas is that the major impetus of all kinds of plant equipment, transporting equipment drives source, be widely used in industry, traffic, the carriers such as aviation, navigation, land transportation, the recovery technology of oil gas has vital impact to social benefit, economic benefit, ecological environment.

At present oil gas reclaims the separation method adopting absorption process, absorption method, condensation method and embrane method, and its recovery process characteristic is shown in Table 1, and from table 1 contrast, can learn: the cost of investment of condensation method oil-gas recovery device is low, application efficiency is high.At present, emptying tail gas concentration≤25g/m ³condensation method oil-gas recovery device, power consumption is 0.17～0.25kWh/m ³, compare absorption method, absorption process and membrane separation process, condensation method is a kind of oil-gas recovery method that operating cost is minimum, investment repayment is the highest.Condensation method Investigation of Petroleum Vapor Recovery Technology is to adopt cooling method to reduce the temperature of oil gas, make the light oil composition cooling liquid in oil gas, currently used cooling, liquefaction mode is to adopt traditional shell and tube exchanger---copper pipe fin type heat exchanger, in the circulation of refrigeration system, oil gas lowered the temperature, liquefied and be separated.This mode is in actual use, and efficiency cooling, liquefaction is very low, and its problem existing in practical operation has: oil gas is disposable passing through in heat exchanger, and the dependence on heat exchanging surface is unique; Oil gas has the danger of meeting naked light blast, therefore be difficult to adopt blower fan (interior live wire circle) to carry out circulation temperature lowering to oil gas, can cause like this film-cooled heat very large, than conventional refrigeration terminal, goes out greatly more than 100 times; Even if reached the required area of lowering the temperature, have again cooling end product volume problem excessive and refrigeration system abnormal circulation and occur, and the excessive initial cost cost causing of volume also can't neglect.

Four kinds of oil gas recovery process method Character Comparisons of table 1

Oil-gas recovery method	Absorption method	Membrane separation process	Absorption process	Condensation method
					Investment	Larger	Greatly	Lower	In
Exhaust emissions concentration/(g/m 3）	10	25	50	≤25（-110℃）
					Energy consumption/(kWh/m 3)	0.20～0.30	0.35	0.30	0.17～0.25
Operating cost	Medium	High	Higher	Lower
					The metering of recovery gasoline	Can indirectly measure	Nothing	Nothing	Accurate-metering
Security	Low	Lower	Medium	High
					Oil gas fluctuation adaptability	Good	Poor	Medium	Better
Occupation area of equipment	Larger	Greatly	Medium	Lower
					Maintenance requirement	Greatly	Larger	Medium	Less

CN2884069Y discloses a kind of Novel finned heat exchanger, this condenser is comprised of housing, fin and condenser pipe, this patent adopts finned cooler, increased area of dissipation, and in order to reduce manufacturing cost, adopted steel pipe and iron plate to make condenser pipe and fin, although this patent has been selected fin condenser, but it does not improve the structure of fin condenser, do not make the rate of recovery improve yet.Therefore, seek a kind of economy, efficient Investigation of Petroleum Vapor Recovery Technology, existing device for recovering oil and gas is substituted and has far reaching significance.

Summary of the invention

In order to solve problems of the prior art, the present invention proposes a kind of cryogenic condensation formula device for recovering oil and gas and using method thereof, this device for recovering oil and gas, by the improvement to fin condenser, can make the cost of condensate recycling device, and organic efficiency improves.

In order to solve problems of the prior art, one of task of the present invention is to provide a kind of multistage cryogenic condensation formula device for recovering oil and gas, and the technical scheme adopting is as follows:

The present invention, a kind of fired multi-stage condensation type device for recovering oil and gas, comprise first order refrigeration system, second level refrigeration system and third level refrigeration system, first order refrigeration system, second level refrigeration system include first condenser and first evaporator fin corresponding with third level refrigeration system, the second condenser and the second evaporator fin, the 3rd condenser and the 3rd evaporator fin, the first condenser, the second condenser and the 3rd condenser are respectively the first fin condenser, the second fin condenser and the 3rd fin condenser, described the first fin condenser, the second fin condenser and the 3rd fin condenser include housing, fins set, refrigerant pipe and the oil-out that is positioned at housing below, the effect of housing is: the overall channel that has formed an oil gas input, fins set is that several fins of arranging side by side that connected successively by pipeline are formed by connecting, on above-mentioned fin, be evenly distributed with several apertures, aperture in adjacent fins is interspersed, aperture passes through for oil gas, the object that aperture in adjacent fins is interspersed is: oil gas can directly not pass through after the aperture by fin in the aperture of next adjacent fins, but can in next adjacent fins, move horizontally, the oil gas moving horizontally can fully contact with fin condenser, and contact area increases, oil gas organic efficiency is improved.

As a preferred version of the present invention, below the first fin condenser, the second fin condenser and the 3rd fin condenser, be all connected with oil drain pan, and the oil drain pan of each condenser below is not independently, but be communicated with, oil drain pan collects and is connected with oil-out, facilitates the recovery of condensed fluid.

Two of task of the present invention is to provide a kind of using method of fired multi-stage condensation type device for recovering oil and gas, and its using method comprises the following steps:

(1) first start first order refrigeration system, meanwhile keep second level refrigeration system and third level refrigeration system to close, oil gas to pass into direction vertical with the first fin condenser, oil gas is vertically squeezed in adjacent fins after by the aperture on fin in the first fin condenser, oil gas moves horizontally and is driven on next adjacent fin by the aperture in adjacent fins in adjacent fins ... according to above-mentioned steps oil gas, continue successively to pass into, carrying out along with refrigeration, when in the first finned evaporator, oil gas temperature is reduced between-10 ℃～10 ℃, now most of steam and a part of lighter hydrocarbons can be condensed into liquid and collect liquid, oil gas is for further processing,

(2) keep the unlatching of first order refrigeration system and third level refrigeration system to close, start second level refrigeration system, it is vertical with the second fin condenser that oil gas in step (1) passes into direction, carrying out along with refrigeration, when in the second finned evaporator, oil gas temperature is reduced between-80 ℃～-30 ℃, the lighter hydrocarbons that are condensed into liquid are collected, kept first order refrigeration system to open and the unlatching of second level refrigeration system;

(3) start third level refrigeration system, when oil gas temperature is reduced between-120 ℃～-100 ℃ in the 3rd finned evaporator, collect liquid, oil gas has reclaimed.

The useful technique effect that the present invention brings:

The finned cooler that the present invention selects, compares with shell and tube condenser of the prior art, and it is cooling, liquefaction efficiency improves greatly;

The finned cooler that the present invention selects, on fin in finned cooler, be distributed with several apertures, and the aperture in adjacent fins is interspersed, can increase the contact area of oil gas and finned cooler, oil gas organic efficiency is improved greatly, its operation principle is as follows: first oil gas is got on fin with vertical passing into, carry out normal impact with heat exchange area, under the effect of low temperature, liquefy, under the effect of inertia, speed up gas and liquid is separated simultaneously, then after the aperture on fin, squeeze on next adjacent fin, do not have the oil gas of liquefaction can on this adjacent fin, move horizontally under the effect of pressure, so just increased the heat exchange efficiency of heat exchange fin, the oil gas not being liquefied can continue to squeeze into adjacent heat exchange fin by aperture along the direction of oil gas, repeat the heat transfer process of a slice fin, go down successively, the gaseous state quantity of oil gas can constantly reduce, oil gas organic efficiency is improved greatly.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail:

Fig. 1 is the right side view of fin condenser of the present invention;

Fig. 2 is the front view of fin condenser of the present invention;

Fig. 3 is gas recovery system for oil flow chart;

In figure, 1, housing 2, fin 3, refrigerant pipe 4, oil drain pan 5, oil-out 6, aperture 7, refrigerant be for liquid interface 8, refrigerant return-air interface.

The specific embodiment

In order to make object of the present invention, technical scheme and advantage clearer, clear and definite, below with reference to specific embodiment, the present invention is described in more detail.

For a better understanding of the present invention, now condensation method oil gas reclaimer operation technique is done to following analysis:

Condensation method Investigation of Petroleum Vapor Recovery Technology is to adopt multistage cooling method continuously, makes the temperature of each component of hydro carbons in mixed oil and gas from gaseous state, become liquid state lower than condensation point, and the air except water vapour keeps gaseous state, thereby realizes the separated of oil gas and air.Its essence utilizes cascade refrigeration circulation to produce low temperature exactly, reduce by stages oil gas temperature, light hydrocarbon component is wherein condensed into the technical matters that liquid is reclaimed, shown in Fig. 3, a technique for condensation method oil gas recovery scheme, oil gas passes into respectively one-level refrigeration system, two-stage system cooling system and three tier structure cooling system and reclaims oil gas.Condensing type oil gas recovery unit of the prior art, comprises first order refrigeration system, second level refrigeration system and third level refrigeration system, belongs to that those skilled in the art can know for the structure of refrigeration system and they parts that comprise, here superfluous stating no longer.

Suppose that oil gas is in condensation process, pressure is atmospheric pressure.Because oil gas is gaseous mixture, while calculating gaseous state, each component parameter of oil gas is mixed according to certain rule, thereby mixture is calculated as imaginary pure material.State equation is Peng-Robinson equation, and this state equation can be predicted the hydro carbons state in wide temperature region well:

$p=\frac{\mathrm{RT}}{V-b}-\frac{a\left(T\right)}{V(V+b)+b(V-b)}$

In formula, a (T)---mist temperature funtion;

a(T)——a/T ^0.5；

The Robert Van de Walle constant of a, b---mist.

A, b mixes according to following rule:

$a=\underset{i}{\mathrm{\Σ}}\underset{j}{\mathrm{\Σ}}{x}_i{x}_j{\left(a_i{b}_j\right)}^{\frac{1}{2}}(1-k_{\mathrm{aij}})$

$b=\underset{i}{\mathrm{\Σ}}\underset{j}{\mathrm{\Σ}}{x}_i{x}_j\left(\frac{b_i-b_j}{2}\right)$

In formula, x _i, x _j---component i, the molar fraction of j in mixture;

A _i, b _i, a _j, b _j---component i, the Robert Van de Walle constant of j;

K _aij---component i, the binary interaction parameter of j.

The state that exists gas-liquid to coexist in condensation process, its equilibrium condition is

condition simultaneous Peng-Robinson, can calculate vapor liquid equilibrium at each temperature thus.

Condensing type oil gas reclaimer adopts multistage overlapping or runback to fold refrigeration technique, although system flow relative complex, its critical component compressor and throttle mechanism all realize local production, and investment and operating cost are lower; And have facility compact, take up room little, automaticity is high, easy to maintenance, security good, be output as the advantages such as fluid oil can directly utilize.

In condensation process, the normal shell-and-tube heat exchanger using, claims again tubular heat exchanger, is to be enclosed in the wall of restraining in housing as the dividing wall type heat exchanger of heat-transfer area.This heat exchanger structure is simpler, and operation is reliable, and available various structural materials (being mainly metal material) are manufactured, and can under high temperature, high pressure, use, and is current most widely used type.

In traditional shell-and-tube heat exchanger, the light pipes that adopt, simple in structure because of it more, easily manufactures, and while needing augmentation of heat transfer, can adopt intensify heat transfer pipe, comprises finned tube, spiral grooved tube, screwed pipe etc.

From thermal conduction study angle analysis, the Basic Ways of augmentation of heat transfer only need be adjusted following three parameters: expansion heat transfer area F, increasing heat transfer temperature difference △ t and raising Coefficient K.Finned tube is compared with light pipe, in the situation that consumption metal material is identical, has larger surface area, belongs to the first augmentation of heat transfer, but be in fact due to the expansion of heat exchange area, to have brought the raising of heat transfer coefficient from intuitively seeing, heat-transfer effect is improved.

Below in conjunction with accompanying drawing, further understand the present invention:

Corresponding the first condenser and the first evaporator fin, the second condenser and the second evaporator fin, the 3rd condenser and the 3rd evaporator fin of including of first order refrigeration system, second level refrigeration system and third level refrigeration system in the present invention, wherein, the first condenser, the second condenser and the 3rd condenser are respectively the first fin condenser, the second fin condenser and the 3rd fin condenser;

Shown in seeing figures.1.and.2, the first fin condenser, the second fin condenser and the 3rd fin condenser include housing 1, fins set, refrigerant pipe 3 and the oil-out 5 that is positioned at housing 1 below, the effect of housing 1 is: the effect of housing 1 is: the overall channel that has formed an oil gas input, several fins 2 of arranging side by side that fins set is connected successively by pipeline form, fin 2 be for oil gas heat exchange, on fin 2, be evenly distributed with several apertures 6, aperture 6 passes through for oil gas, aperture 6 in adjacent fins 2 is interspersed, the object that aperture 2 in adjacent fins is interspersed is: oil gas can directly not pass through after the aperture by fin in the aperture of next adjacent fins, but can in next adjacent fins, move horizontally, the oil gas moving horizontally can fully contact with fin condenser, and contact area increases, oil gas organic efficiency is improved, the first fin condenser, the second fin condenser and the 3rd fin condenser all also include refrigerant for liquid interface 7 and refrigerant return-air interface 8, and refrigerant is entrances of cold-producing medium for liquid interface 7, and refrigerant return-air interface 8 is outlets of cold-producing medium.

As a preferred version of the present invention, below the first fin condenser, the second fin condenser and the 3rd fin condenser, be all connected with oil drain pan 4, and the oil drain pan of each condenser below is not independently, but be communicated with, the liquid that condensation is got off is all collected in oil drain pan, oil drain pan collects and is connected with oil-out 5, facilitates the recovery of condensed fluid.

The using method of above-mentioned cryogenic condensation formula device for recovering oil and gas, its using method comprises the following steps:

1) first start first order refrigeration system, meanwhile keep second level refrigeration system and third level refrigeration system to close, oil gas to pass into direction vertical with the first fin condenser, with reference to Fig. 1, it is that the direction perpendicular to fin passes into from right side that oil gas of the present invention passes into direction, first oil gas vertically squeezed in adjacent fins by the aperture 6 on fin in the first fin condenser is rear, certainly, adjacent fins described here is to pass into the consistent adjacent fins of direction with oil gas, it is vertical with fin that oil gas passes into direction, can force gas and heat exchange area normal impact, under the effect of low temperature, liquefy, under the effect of inertia, speed up gas and liquid is separated simultaneously, oil gas moves horizontally and is driven on next adjacent fin by the aperture in adjacent fins in adjacent fins ... according to above-mentioned steps oil gas, continue successively to pass into, carrying out along with refrigeration, when in the first finned evaporator, oil gas temperature is reduced between-10 ℃～10 ℃, now most of steam and a part of lighter hydrocarbons can be condensed into liquid and collect liquid, oil gas is for further processing,

2) keep the unlatching of first order refrigeration system and third level refrigeration system to close, start second level refrigeration system, it is vertical with the second fin condenser that oil gas in step (1) passes into direction, carrying out along with refrigeration, when in the second finned evaporator, oil gas temperature is reduced between-80 ℃～-30 ℃, the lighter hydrocarbons that are condensed into liquid are collected, kept first order refrigeration system to open and the unlatching of second level refrigeration system;

3) start third level refrigeration system, when oil gas temperature is reduced between-120 ℃～-100 ℃ in the 3rd finned evaporator, collect liquid, oil gas has reclaimed.

With reference to table 2, table 2 is the corresponding relation of condensation temperature in the present invention and the rate of recovery.

Table 2

Condensation temperature/℃	The rate of recovery	Exhaust emissions concentration/(g/m 3)
			-40	70%	—
-75	90%	≤50
			-95	＞95%	≤35
-110	＞98%	≤25
			-120	＞99%	≤15

From table 2, can learn: when condensation temperature is-120 ℃, oil gas recovery rate reaches more than 99%.

Claims (3)

1. a fired multi-stage condensation type device for recovering oil and gas, comprise first order refrigeration system, second level refrigeration system and third level refrigeration system, described first order refrigeration system, second level refrigeration system include first condenser and first evaporator fin corresponding with third level refrigeration system, the second condenser and the second evaporator fin, the 3rd condenser and the 3rd evaporator fin, it is characterized in that: described the first condenser, the second condenser and the 3rd condenser are respectively the first fin condenser, the second fin condenser and the 3rd fin condenser, described the first fin condenser, the second fin condenser and the 3rd fin condenser include housing, fins set, refrigerant pipe and the oil-out that is positioned at housing below, described fins set is that several fins of arranging side by side that connected successively by pipeline are formed by connecting, on described fin, be evenly distributed with several apertures, aperture in described adjacent fins is interspersed.

2. a kind of fired multi-stage condensation type device for recovering oil and gas according to claim 1, is characterized in that: below the first fin condenser, the second fin condenser, the 3rd fin condenser, be all connected with oil drain pan, described oil drain pan collects and is connected with oil-out.

3. the using method of a kind of fired multi-stage condensation type device for recovering oil and gas according to claim 1 and 2, is characterized in that said method comprising the steps of:

(1) first start first order refrigeration system, meanwhile keep second level refrigeration system and third level refrigeration system to close, oil gas to pass into direction vertical with the first fin condenser, oil gas is vertically squeezed in adjacent fins after by the aperture on fin in the first fin condenser, oil gas moves horizontally and is driven on next adjacent fin by the aperture in adjacent fins in described adjacent fins, continue successively, carrying out along with refrigeration, when in the first finned evaporator, oil gas temperature is reduced between-10 ℃～10 ℃, now most of steam and a part of lighter hydrocarbons can be condensed into liquid and collect liquid, oil gas is for further processing,

(2) keep the unlatching of first order refrigeration system and third level refrigeration system to close, start second level refrigeration system, oil gas in step (1) to pass into direction vertical with the second fin condenser, carrying out along with refrigeration, when in the second finned evaporator, oil gas temperature is reduced between-80 ℃～-30 ℃, the lighter hydrocarbons that are condensed into liquid are collected, kept first order refrigeration system to open and the unlatching of second level refrigeration system;

(3) start third level refrigeration system, when oil gas temperature is reduced between-120 ℃～-100 ℃ in the 3rd finned evaporator, collect liquid, oil gas has reclaimed.

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