Diploma project "Modernization of AVT-1 plant with new equipment (plate heat exchanger) to reduce losses of gasoline with fatty gas"

Contents

SODRZHANIYE

INTRODUCTION

1. LITERARY REVIEW

1.1. Plate heat exchangers

1.2. Mass exchange processes

1.2.1.The basics of mass transfer theory

1.2.2. Rectification Basics

1.2.3. Rectification Columns

1.2.4. Tray types

1.2.5. Complex column

1.2.6. How to create reflux in a column

1.2.7. Ulites and breakaway properties of columns

1.2.8. Gas cleaning

1.3. Thermal processes

1.3.1. Main reciprocal traffic patterns

heat exchanging streams

1.3.2. Heat exchangers

1.3.3. Heat exchanger classification

1.4. Air cooling devices

1.5. Tube furnaces

1.5.1. Main performance indicators of furnaces

1.5.2. Composition of combustion products

1.5.3. Classification and types of tube furnaces

1.5.4. Structural elements of furnaces

1.5.5. Tube furnace headsets

1.5.6. Chimneys and chimneys

1.5.7. Pipe Furnace Superheaters

1.5.8. Tube furnace recuperators

1.5.9. Recovery Boilers

2. PROCESS PART

2.1. Process and Flow Diagram Description

2.1.1. The essence of the oil refining process

2.1.2. Main Process Flow Diagram Description

2.1.3. Rectification column K-

2.1.4. Tube furnace P-

2.1.5. Rectification column K-

2.1.6. Vacuum column K-

2.1.7. Vacuum generating equipment

2.1.8. Snap-in unit

2.1.9. Acid effluent pumping unit

2.1.10. Fuel Gas Separator

2.1.11. Unit flare system

2.2. Design Task

2.3. Process calculation of P- furnace

2.3.1. Initial data for calculation of P- furnace

2.3.2. Combustion calculation

2.3.3. Calculation of radiant cameras

2.3.4. Calculation of convection chambers

2.4. Rectification Column Calibration

2.4.1. Calculation of K- rectification column

2.4.2. Calculation of K- diameter

2.4.3. Calculation of K- height

2.4.4. Calculation of K- rectification column

2.4.5. Calculation of column diameter K-

2.4.6. Calculation of height of a column To -

2.5. Absorption unit

2.6. Calculation of the HV-1, HV-air coolers

2.7. Plate heat exchanger calculation

3. MECHANICAL PART

3.1. Selection of material for making the apparatus

3.2. Calculation of flange connections

4. Instrumentation & A

4.1. Common Tasks and Automation

4.2. Process Facility Analysis

4.3. Proposed parameters for monitoring

4.4. Select Automation Tools

5. SAFETY OF LIFE

5.1. Analysis of harmful and hazardous production factors

5.2. Classification of process units by explosion hazard

5.3. Fire hazard classification

5.4. Characteristics of production hazard

5.5. Safety measures during operation of production facilities

5.5.1. Safety requirements during start-ups and stops

of process systems

5.5.2. Safety precautions for plant shutdown

5.5.3. Putting equipment in reserve

5.5.4. Safety measures in process maintenance

process

5.5.5. Main hazards of production

5.6. Possible emergencies and how to resolve them

5.7. Safe handling of pyrophoric deposits

5.8. Methods of decontamination and neutralization of products

production in case of bottles and accidents

5.9. Personal protective equipment for workers

5.10 Possibility of accumulating static electricity charges

5.11. Safe method of removing production products

5.12. Main hazards of used equipment and

pipelines

5.13. Safety and Emergency Response Measures

protection

5.14. Calculation of lightning protection of ATS unit

6. ENVIRONMENTAL SECTION

6.1. Production waste

6.1.1. Wastewater

6.1.2. Emissions to the atmosphere

6.2. Characteristics of harmful substances properties

7. ECONOMIC PART

7.1. Feasibility study

7.2. Capital Cost Calculation

7.3. Calculation of depreciation charges

7.4. Calculation of economic effect

CONCLUSION

List of literature used

Application

Application

Application

Summary

The purpose of this diploma project is to assess the possibility of retrofitting the AT unit of the AVT-1 unit from a technological and economic point of view, which is primarily aimed at retrofitting the AVT-1 unit with new equipment (plate heat exchanger) in order to reduce losses of gasoline with fatty gas.

The project consists of the following sections: literature review, technological, mechanical, instrumentation and A, labor protection, environmental, economic.

The process section includes calculation of K1, K-2 rectification column, HV1, XV-2 air coolers, P-1 furnace during basic design operation and plate heat exchanger. Column calculation was carried out in DESIGN II.

In the mechanical section, the material was selected for the plate heat exchanger and the flange joints were designed for strength.

Section I&C shows the automation diagram of the absorption unit.

In the occupational safety section, the hazardous factors of the AT unit of the AVT1 unit are considered, emergency prevention methods and actions are indicated in case of an emergency. Lightning protection of the column block was also calculated.

The environmental section considers sources of harmful emissions and substances that pose a danger to the environment and human beings.

The economic section carried out a feasibility study of the project, calculated changes in capital and current costs and expected profit.

The diploma project contains 159 pages, 13 illustrations, 5 diagrams, 23 tables, 3 annexes, 29 literature sources. The graphic part is presented on 8 sheets of A1 format.

Introduction

As technological progress develops, the problems of deepening oil refining, that is, obtaining the maximum number of light fractions and improving the quality of oil products, become increasingly important for oil refining.

Not the last place in solving these problems is given to the production of primary processing. At the same time, we mean, first of all, in relation to primary distillation plants - an increase in the depth of distillate extraction from oil and a decrease in losses of the main product.

At modern refineries, AVT plants are the main ones in the entire process chain of oil processing and determine the capacity of the plant as a whole. The total number of distillates released from oil for AVT ranges from 7 to 10, and each of them is sent to further technological operations.

Currently, the policy of oil refineries is aimed at reducing losses, which will increase the output of basic products and will affect its cost.

The main fire devices at the AVT plant are tubular furnaces of various types and designs. The most common are double-pitched ovens of the tent type, ovens with radiating walls and vertically flare type. These two-pitched tent type furnaces require fuel gas to heat the feed. At the moment, AVT-1 plant furnaces use fatty gas as fuel gas, which is taken from K1 stripping column. It is known that fatty gas has gasoline components in its composition, resulting in a decrease in the production of the main products of the plant.

Therefore, the diploma project provides for the retrofitting of the AVT-1 unit with a plate heat exchanger in order to reduce losses of gasoline components.

1. literary review

1.1. Plate heat exchangers

Disassembled, disassembled with double plates (semi-disassembled) and non-disassembled (welded) heat exchangers are designed for heat transfer processes.

Dismountable heat exchangers can operate at pressure from 0.002 to 1 MPa (from 0.02 to 10 kgf/cm2) in temperature of working media from 253 to 453 K (from 20 to + 180 ° С).

Disassembled with double plates (semi-disassembled) - at pressure from 0.002 to 2.5 MPa (from 0.02 to 25 kgf/cm2) at the same temperature of working media as for disassembled heat exchangers.

Unassembled (welded) - at pressure from 0.000 to 4 MPa (from 0.002 to 40 kgf/cm2) and temperature of working media from 173 to 573 K (from - 100 to + 300 ° С).

Plate heat exchangers are characterized by high intensity of heat transfer and heat transfer processes with moderate hydraulic resistances. They can be used to recover heat between working media streams in coolers, heaters, condensers and refluxers. Heat exchangers can be double-threaded and multi-threaded, that is, they can be used for heat exchange between two working media (double-threaded), as well as for heat exchange between three, four and a large number of media in one apparatus.

In plate heat exchangers it is possible to perform heat exchange between working media liquid - liquid, steam - liquid, steam + gas liquid, gas - liquid, gas - gas.

Dismountable heat exchangers can be used to treat suspensions with solid particles with a size of not more than 4 mm.

When the contaminants are deposited on the heat transfer surfaces, it is possible to periodically switch the channels to working media which clean the surfaces of contaminants without disassembling the apparatus.

Non-detachable plate heat exchangers are designed to work with working media that do not form hard-to-dissolve contaminants on heat transfer surfaces that are amenable to chemical washing.

Plate heat exchangers can be used to treat various solutions with kinematic viscosity of 0.2-106 to 60-103 m2/s.

In heat transfer plates of detachable heat exchangers along the circuit there is a slot in which sealing gaskets made of rubber of special heat-resistant grades are fixed. Plates are installed on heat exchanger frame consisting of bearing rods, movable and fixed plates with clamping screws. The fixed plate is usually attached to the floor, the movable plate is suspended on the roller from the upper bar and can move along it. Connectors for connection of process pipelines are located on the plates.

With a single-pack arrangement of plates, it is allowed to install all four connectors on a fixed plate, which facilitates the operation of the device.

More than four nozzles can be installed on the heat exchanger, for example, if it is necessary to remove non-condensed gases, drain products, etc.

Demountable and semi-disassembly heat exchangers are installed on cantilever frame, on double-support frame, on three-support frame or frame with fixed support in the middle of frame. Non-detachable heat exchangers (welded structure) are installed on special supports.

Capacitors have single-packet arrangement of plates on steam stroke side. Heat exchangers with intermediate plates can be multi-threaded, i.e. they can operate with three working media or more.

The main part of the detachable plate heat exchanger is a corrugated heat transfer plate.

In the channels of the apparatus composed of plates, corrugation support points are provided, which allows to maintain pressure difference in the apparatus on both sides of the plate, as well as increased internal pressure in the channels while maintaining tightness.

A group of plates forming a system of channels in which the working medium moves in only one direction constitutes a stack.

One or more packs compressed between fixed and movable plates form a section. During assembly of the package, the plates are turned relative to each other by 180 °, all rubber gaskets facing the movable plate. Holes for passage of working media are located in corners of plates. In the intermediate and end plates there may be one, two or three holes, the number of which is determined in accordance with the layout diagram of the plates in the heat exchanger.

Each plate in the operating apparatus is washed with two working media: on the one hand - cooled, and on the other - heated; as a result, heat exchange occurs between media. Media flowing across the corrugations turbulize, which contributes to the intensification of heat exchange.

1.2.3. Rectification Columns

Rectification columns are vertical cylindrical apparatuses designed to clearly separate a mixture of two or more mutually soluble liquids to obtain the desired concentration of the desired products, subject to different boiling points of these liquids.

Distillation columns designed to produce two products, one of which (distillate) is withdrawn in the vapor phase by the top of the column, and the other in the form of liquid product (residue) withdrawn by the bottom of the column are filled with simple distillation columns. The portion of the column into which the feed is introduced is called the feed section. The portion of the column above the feed feed is called concentration or reinforcement, and below the feed is called stripping or exhaustive.

Depending on the purpose of the columns, they may be full, having concentration and distillation sections, or incomplete: the reinforcing column does not have a distillation section, and the distillation column does not have a concentration section. The feed is introduced into the concentration column under the bottom tray, and into the distillation column - to the top.

Depending on the purpose, rectification devices are divided into columns for atmospheric distillation of oil, stripping, vacuum distillation of fuel oil, stabilization, etc. Depending on pressure - atmospheric, vacuum, working under pressure. According to the method of contact - on poppet and nozzle. Most plants use poppet columns.

Poppet columns

In poppet columns, steam or gas passes through a layer of liquid on the tray. At the same time, the steam is divided into small bubbles and jets, which move at high speed in the liquid, forming a gas-liquid system.

There are poppet columns with overflow devices and columns with unorganized overflow of liquid or with failed trays.

Columns with failed trays operate in "hanging" mode, that is, the steam (gas) flow rate is selected so that a part of the holes passes through the liquid failure. Failed trays are sieve or lattice discs. Failed trays are supplied with emergency overflow pipes in case of liquid flooding.

The reflux is drained to the underlying tray, as well as the vapors are lifted from the space through the holes of the tray. Trays of this type can only operate in narrow ranges of steam and liquid loads.

Poppet columns with overflow devices have horizontal trays and overflow device maintaining the specified level of liquid on the tray.

Liquid is supplied to each tray from the overlying tray through drain devices in the form of pipes or flat partitions. With the help of parts of these pipes or partitions protruding above the trays, the required level of liquid on each tray is maintained. The lower ends of the drain pipes and partitions shall be immersed in the liquid on the underlying tray. Due to the resulting hydraulic gate, the free ascent of vapors through the drains is prevented. In the bottom of the hydraulic lock pocket there are holes for oil product discharge, which are necessary during preparation of the column for repair.

1.2.4. Tray types

The most widely used trays with round caps, grooved, S- shaped, valve.

They are steel discs in which cups (nipples) are installed, protruding above their surface. Each cup is covered with a cap so as to allow free passage of incoming from the underlying tray. During operation, the caps are immersed in the liquid layer, and as a result, a hydraulic gate is formed that bubbles the vapors. The cap design allows the height level to be adjusted. Plates are complex and bulky, rarely used.

Grooved trays

A square is inscribed in the cross section of the column, defining four segments: two blind, the third - the tray pocket and the fourth - the drain device. In blind segments there are beds in which gutters are mounted. From above, the free space between the troughs is closed with tunnel caps adjustable in height. The vapors pass between the chutes, fall under the caps and are drilled through a layer of liquid located on the tray.

The main drawback is the small area of ​ ​ bubbling, which leads to the takeover of the phlegm.

Tray with S-shaped elements

In trays with S-shaped caps, the liquid, heading to the drain device, moves across the caps, and the caps themselves are integral with the trough. Each S-shaped element consists of a cap and a groove part. When assembled, they are arranged so that the cap part of one element overlaps the grooved part of the other, forming a hydraulic gate. Trays of S-shaped elements are intended for columns operating at atmospheric or low pressure. They are characterized by stable, uniform operation when changing loads. The capacity of the trays is 20% higher than the grooved ones.

Valve trays

Valve trays are solid or assembled from several sections discs in which there are oblong slots or rounded holes. Slots (holes) are covered by valves held to the plate by clamps or shoulders of the valve. Depending on the vapour head, the valves are raised to different heights, i.e. the valve tray operates dynamically. In cases where very large changes in loads are possible, the trays are equipped with valves of various weights. The general disadvantage of all valve trays is the possibility of clogging or coking the valves, as a result of which they lose their throughput and stop working dynamically, providing more resistance to rising vapors of petroleum products. Often, the caps are torn off, which leads to a sharp deterioration in the column regime.

1.5. Tube furnaces

Tubular furnace serves to heat oil and oil products with heat of fuel combustion products and furnace chamber. In the tubular furnace, the heated raw material moves in the coil tubes, and the hot combustion products are washed, the pipes are outside. The tubular furnace typically has two chambers, radiant, in which the fuel burns, and heat is transferred to the pipes mainly by radiation from heated combustion products and heat transfer of wall masonry, in which heat is transferred to the pipes when hot combustion products contact the pipes, i.e. by convection. The radiant and convection chambers are separated by an overhang wall.

The amount of radiant heat absorbed in the radiant chamber depends on the surface of the flare, its configuration and the degree of shielding of the furnace. The large surface of the flares and the increased masonry area contribute to the increased efficiency of heat transfer in the radiator chamber.

The efficiency of heat transfer by convection is due to the speed of flue gases. For more complete flow of furnace pipes in convection bundle and formation of turbulent movement of flue gases, pipes in bundle are arranged in staggered order. Sometimes ribbed pipes with a developed surface are used.

The furnaces are characterized by compact design, high thermal power, high heating speed, easy maintenance.

1.5.1. Main performance indicators of furnaces

The furnace capacity is representative of the amount of feed fed to the furnace for heating per unit time.

The thermal power of the furnace determines the amount of heat that can be received by the raw material in the furnace.

The heat stress of the heating surface characterizes the amount of heat transferred through the pipe surface unit per unit time.

The efficiency of the tubular furnace is the ratio of the useful heat to the total heat generated by the combustion of the fuel. The efficiency of the furnaces depends on and, the temperature of the flue gases, thermal insulation and is 0.650.85 .

The plants use liquid and gaseous fuel, mainly gas, fuel oil, oil processing products. Oxygen is needed to burn the fuel. In the practical combustion of fuel due to its incomplete contact with air oxygen, a larger volume of air is required compared to the theoretical one. The ratio of actual air flow to theoretical is called the excess air factor and is denoted by < u >.

The value of u depends on the type and method of combustion of the fuel, the design of the furnace, burners, etc. The smaller the u value, the more economical the tube furnace is.

1.5.2. Composition of combustion products

In case of complete combustion of fuel, flue gases include carbon and sulfur dioxide, water vapors, excess oxygen and nitrogen. In the case of incomplete combustion, there may be carbon monoxide, hydrocarbons, carbon, etc .

The temperature of the exhaust combustion products should be low enough to reduce heat loss with the combustion products. This is achieved by the following indicators.

When leaving the convection chamber, the combustion products should have a temperature of 100115 ° C higher than the temperature of the raw material entering it. In case of natural thrust, the temperature of exhaust flue gases must not be more than 250 ° С. The flue gas temperature may be lower when using a flue gas.

Some of the heat of the flue gases can be used to preheat the combustion air in the recuperators. Recovery boilers can be installed on the flue gas stream in order to obtain water vapor and increase the efficiency of the furnaces.

1.5.4. Structural elements of furnaces

The modern tube furnace consists of the following main units: foundation, frame, vault, walls, pipe coil, headset, fuel combustion equipment, chimney and chimneys.

Foundations of tubular furnaces are made of monolithic or prefabricated reinforced concrete protected from groundwater. On top of the foundation from high temperatures is separated by ordinary brick.

The tubular furnace frame is a system of vertical metal columns interconnected by horizontal and inclined beams forming a rigid structure. The framework of the furnace perceives loading from a pipe coil, pipe lattices and pendants, roofs, the arch and walls of the furnace.

The furnace walls and arches have a block structure assembled from refractory bricks of various shapes. To give strength and protection against atmospheric effects, the steppes and arch are covered with a steel casing.

Pipe coils, depending on the process, are used in tubular furnaces from pipes with a diameter of 60 to 219 mm and a wall thickness of 6 to 15 mm. Seamless pipes from carbon steel of grades 10 and 20 (at a temperature of up to 450 ° C) and from alloyed steels X5M, X5MU, 12X8VF, X (M) (at a temperature of up to 550 ° C) are used. At higher temperatures, pipes from heat-resistant steels (12X18N10T) or from heat-resistant alloys are used. Carbon steel pipes are used only in non-aggressive media. The pipes are connected to the coil by welded wedges or retro ends fixed at the pipe ends by means of flaring. Pipe connection with retro ends is used when pipes need to be opened for cleaning, inspection and revision. Returbends are steel leaves or forged boxes connecting pipes into a coil. The direction of flow in them changes to the opposite. The design of the retro ends allows access to the inner surface of the furnace pipes. For this purpose cone plugs are removed from housing seat, which cover cone and are pressed to it by cross-piece bolts.

1.5.6. Chimneys and chimneys

Chimneys provide the traction required for the operation of tubular furnaces. The thrust depends on the height of the pipe, the temperature of the smoke lawn and the temperature of the atmospheric air. Furnace vacuum created by chimney 15200 mmW Pipes are usually made of metal, the lower part of which is lined from the inside with refractory bricks.

1.5.7. Pipe Furnace Superheaters

Sometimes, in the convection chamber of the furnace, in addition to the coil for heating the raw materials, a coil is placed for overheating the water vapor used for technological needs. This arrangement in the convection chamber is inconvenient, since in the case of a run-through it is difficult to change the pipes, therefore, on tubular furnaces, superheaters are inserted into the boards with a corresponding increase in the surface of the pipes to ensure the necessary temperature. Superheater is a radiator consisting of two headers interconnected by small-diameter tubes.

1.5.8. Tube furnace recuperators

In order to increase the efficiency of furnaces and create favorable fuel combustion modes, the heat of flue gases is used to heat the air supplied to the furnace. For this purpose recuperators - devices for air heating are installed in boards. The air is blown by the fan into the annular space closed by the casing, and then through the air ducts it enters the nozzles.

1.5.9. Recovery boilers

To fully use the heat of flue gases, special recovery boilers are installed on their flow. They serve to produce steam and are a heat exchanger, in the tube space of which the water level is maintained, and flue gases pass through the tube space. Traction in this case will be created by the smoke pump.

Process Part

Oil is a complex liquid mixture of closely boiling hydrocarbons and high molecular weight hydrocarbon compounds. Oxygen, sulfur, nitrogen and some metals are included in the oil in the form of various compounds. Non-hydrocarbon compounds, organic acids and other substances are also contained in the oil in small amounts.

Distillation is the process of partially boiling a liquid solution or condensing a vapor solution of different volatility substances to produce one product of more volatile and the other less volatile than the original solution.

The reason for the change in the composition of the initial solution during the boiling or condensation processes is the separation of a new phase from it. It has a composition that is equilibrium with the initial solution, but quantitatively different from it. This fact, as well as the sharp difference in the densities of the vapor and liquid phases, allowing them to be easily separated from each other, form the basis for the industrial application of distillation.

Rectification is a process of separating solutions into components by multiple two-way mass exchange between counter-current moving vapors and liquid. The reaction of phases in rectification is the diffusion of a low boiling component from liquid to steam and a high boiling component from steam to liquid.

When oil is separated by distillation and rectification, fractions and distillates are obtained, which boil out in a certain temperature range and are complex mixtures.

In modern oil processing technology, primary distillation is used mainly to obtain raw materials for subsequent processes.

2.1. Process Description and Process Diagram of Production Facility

2.1.1. Essence of Crude Oil Processing Process

The process of oil processing at the atmospheric vacuum tube plant consists of the following stages:

- preliminary heating of crude oil in heat exchangers due to heat of waste products;

- fractionation of oil heated in heat exchangers in the first K-1 rectification column for its stripping;

- heating of semi-gasoline oil in tubular furnaces P1, P-2;

- fractionation of heated semi-gasoline oil in the second rectification column K-2 to obtain the upper product - straight-run gasoline, side cuts - straight-run fraction for the production of PT, diesel straight-run fuel and fuel oil;

- fractionation of fuel oil in vacuum column K-5 to obtain vacuum distillates and tar;

- latching of gasoline of the first and second distillation columns K-1 and K-2.

To protect the equipment from corrosion, ammonia water is supplied to the helmet of the K-2 column and 1-2% alkaline solution to oil. Alkaline solution and ammonia water are supplied depending on pH in drain waters of tanks E1a, E-2 .

2.1.6. Vacuum column K-5

Top temperature, ° С - not higher than 240;

Bottom temperature, ° С - not more than 380;

Residual pressure, mm Hg. Art. - 40-60.

During the 1993 overhaul, 5 layers of the Sulzer Mellapak nozzle were installed in the K-5 vacuum column instead of grooved trays.

In addition, in the upper part of the column, an irrigated T-shaped drip dryer with a regular nozzle is mounted.

Three screw regular packing trays are mounted in the lower part, above which a zigzag baffle rectification unit and a blind tray of layer No. 5 are located in the raw material injection zone.

Packing layer No. 1

Top (inside diameter 4400 mm):

liquid distributor;

layer of structurally laid nozzles;

liquid manifold with integrated support system;

column nozzle (inside diameter 4400 mm).

Packing layer No. 2

Separation part (inside dimension 4400 mm):

liquid distributor;

layer of structurally laid nozzles;

liquid manifold with integrated nozzle support system;

column nozzle (inside diameter 4400 mm).

Packing layer No. 3

Lower pump part (internal diameter 6400 mm):

liquid distributor;

layer of structurally laid nozzles;

liquid manifold with integrated nozzle support system;

Packing layer No. 4

Separation part (internal diameter 6400 mm):

liquid distributor;

layer of structurally laid nozzles;

liquid manifold with integrated nozzle support system;

Packing layer No. 5

Wash section (internal dimension 4400 mm):

liquid distributor;

layer of structurally laid nozzles;

blind plate;

column nozzle (inside diameter 4400 mm).

Vacuum gas oil is removed from the pocket of liquid layer No. 1, which is pumped by pumps H22,23 through heat exchangers T6/5; T-6/1 is cooled in HV5 air cooling apparatus (2 sections) and returns to K-5 sprinkling on the baffle device and the first nozzle layer through two lines. Excess vacuum gas oil is removed from the unit.

K-5 top temperature is adjusted by pos. TIRCA 1046 with flow correction pos. FIRC 3032, the control valve is located on the reflux line supplied to the baffle. The reflux rate for the 1st layer of the nozzle is adjusted pos. FIRC 3033, control valve is installed on the line of sprinkling supply to the 1st layer of the nozzle. The flow rate of the vacuum gas oil from the unit is adjusted pos. FQIRC 3002, with level correction in the pocket of the first layer of column K-5, pos. LIRCA 4017, the valve is located at the outlet line of the vacuum gas oil from the unit .

Medium viscous distillate is removed from the liquid layer pocket 2, which is pumped by pumps H24,25 through heat exchangers T7/1,2; T6/4 and after cooling in 2 sections of air cooling apparatus HV5/1,2 is removed from the unit. The level in the pocket of the 2nd layer is controlled by the valve pos. LIRCA 4018 installed on the medium viscous distillate pumping line from the unit. The flow rate of the second cut from the unit is recorded in pos. FQIR 3006.

To control the temperature mode of the column, circulating reflux is removed from the pocket of the nozzle layer 3, which is pumped by pumps H26,27 through heat exchangers T7/3,4; T-6/3 is cooled in HV6 air cooling apparatus and returned to the column for reflux of the 3rd nozzle layer. Circulation sprinkling flow rate for 3 nozzle layer is controlled by pos. FIRC 3034, valve is installed on circulation reflux line. The level in the layer pocket 3 is recorded in pos. LIRA 4019.

Viscous distillate is removed from the pocket of the nozzle layer 4, which is pumped by pumps H28,29 through heat exchangers T5/3,4 and T4/1,2, cooled in two sections of air cooling apparatus HB5 and removed from the unit. Part of viscous distillate from H28.29 pumps discharge is returned to the column to the 5th layer as hot reflux.

Hot reflux flow rate per 5 nozzle layer is controlled by valve pos. FIRC 3035, installed on the line of return of the cut to K-5. Level in pocket of 4 layer pos. The LIRCA 4020 is controlled by a valve on the W line of the plant cut. The flow rate W of the cut from the unit is recorded pos. FQIR 3000.

Darkened fraction (slop) is removed from the pocket of layer 5, which is pumped by pumps H30,31 through heat exchangers T8/5; T-8/6 is cooled in 3 sections of HV6 air cooling apparatus and withdrawn from the unit. Slop flow rate from the unit is recorded in pos. FQIR 3008, level in layer pocket 5 is adjusted by pos. LIRCA 4022, the valve is located on the slop line from the unit.

From a bottom of a column of K-5 tar which is pumped over by the pumps H32/1.2 via T8/7 heat exchangers is removed; T8/4; T8/3; T8/1; T3/1.2; T1; T32 is also removed from installation. Tar flow rate is recorded pos. FQIR 3007, the level in the K-5 cube is regulated by pos. LIRCA 4021, valve is installed on the tar outlet line from the unit. To control the temperature conditions of the bottom of the K-5 column, part of the tar (cooling) after T-1 is supplied to the bottom of the column. The couling flow rate is adjusted pos. FIRC 3036, control valve is installed on the cooling line in K-5.

2.1.7. Vacuum generating equipment

Decomposition gases from the vacuum column K-5 through the helmet pipes are supplied under the lower tray of the baromcondenser, condensed in the inter-plate space on the packages of the regular nozzle due to contact with cooling liquid (diesel fuel).

Due to heat and mass exchange, the bulk of the oil introduced from the vacuum column is condensed and absorbed.

Diesel fuel is supplied after HV4 air cooling device to the upper plate of A10 barr condenser. Diesel fuel consumption is regulated by pos. FIRC 3037, the control valve is established on the line of diesel fuel in A10. Saturated diesel fuel from a baromkondensator is pumped out by the pumps H10.11. Diesel fuel consumption is regulated by pos. FIRC 3009, the control valve is established on a vykida of H10.11, with correction on level in A10 of poses. LIRCA 4023. Pressure in the pressure condenser is recorded pos. PIR 2012, 2013. Diesel fuel outlet temperature is recorded in pos. TIR 1059.

Part of decomposition gases not condensed in the baromcondenser is sucked by 3-stage steam jet ejector A18, additionally condensed in 2 intermediate condensers-coolers of the ejector and discharged to the sewage system.

The remaining decomposition gases after the third stage of the ejector are discharged to the P-1 furnace for burnup to the combustion chamber or atmosphere.

Diesel fuel from the drum condenser is cooled in the air cooling apparatus HV6 (2 sections) and withdrawn from the unit. To create pressure on the pump and prevent air flow into the vacuum generating system, the hydraulic gate column at the reception of pumps H10,11 pumping absorbent from A10 is installed at least 11 meters. Water for cooling of intermediate coolers of the ejector is supplied by pumps from water unit No. 313.

2.1.8. Snap-in unit

Snap-in is used to clean gasoline from sulfur compounds, which cause corrosion of pipelines and equipment. The process of gasoline snapping is carried out by 1012% alkali solution in settler A-1 with subsequent separation of water in settler A-4.

To neutralize the action of sulfur compounds, as well as acids formed as a result of hydrolysis of chloride salts, it is provided to snap oil with an alkaline solution. The concentration of the operating solution of the latching reagent shall be 12%. Reagent is supplied by H34a pump to oil pipeline upstream of H1, 36 feed pumps. The consumption of alkaline solution is controlled by the level in A-6 and is controlled depending on the value of pH drainage water from E1a, which should be maintained in the range from 7 to 9.5 units.

In addition, in order to neutralize hydrogen sulfide (H2S) and hydrogen chloride (HCl), an aqueous ammonia solution with a concentration of 12% by weight is supplied to the helmet line K-2 in front of the air cooling apparatus from the reagent farm. Ammonia solution flow rate is controlled by valve pos. FIRC 3022, depending on the value of pH drainage water from E2, which should be maintained in the range from 7 to 9.5 units, the control valve is installed on the ammonia water supply line K-2.

2.1.9. Acid effluent pumping unit

Water from E1a and E-2 is supplied to E-4 tank. In tank E-4 there is additional separation of oil product from water. Water from E-4 arrives on reception of the pumps N35.35a and is pumped out on AVT-5 otparka block. The water level in E-4 is recorded pos. LIR 4003, controlled by valve pos. LIRCA 4002, control valve installed on discharge line of pumps H35, 35a. Water flow rate from E-4 is recorded in pos. FIR 3004. The level of gasoline in E-4 is recorded pos. LIRA 4004. It is possible to discharge water from E-4 to PLC.

2.1.10. Fuel Gas Separator

Dry gas from FRG is supplied to fuel gas separator K-4. Gas pressure from FRG is regulated by pos. PIRC 2002, control valve is installed on the gas supply line to the plant. Gas flow rate from FRG is recorded in pos. FIR 3011. The pressure in K-4 is adjusted pos. PRCA 2004, valve is installed on gas supply line to K-4. Gas from K-4 is supplied to heat exchanger T19/1,2, where it is heated due to heat of the 1st part. K-2 and enters the furnaces nozzles. Condensate level in K-4 is recorded in pos. LIRA 4009. Condensate from the bottom of K-4 is periodically pumped by N34 pump to the gasoline line from the unit.

2.1.11. Unit flare system

To ensure safe operation of the plant devices when the pressure is higher than the working one, overpressure is released:

- from K1,2,4 columns and E1a tank through E-3 tank to HP flare;

- from A1, A-4, A-7 in A-5 settler.

The process diagram provides overpressure relief from tank E-2 to flare tank E-3.

Condensate level in E-3 is recorded in pos. LIRA 4000, 4001. Pressure in E-3 is recorded pos. PIR 2015. Condensate from E-3 is periodically pumped out by the pump N33.33a to the line of not standard on reception of raw pumps, or in the area of not standard to the ELOW park. Level in A-5 is visually monitored. Condensate from A-5 is pumped to the gasoline line by H34 pump.

2.2. Design Task

In this thesis, a verification calculation was carried out; K1, K-2 rectification column, P1 tent furnace, HV1, XV-2 air coolers, and AVT-1 unit plate heat exchanger. According to the existing process scheme, the fatty gas is supplied to the furnaces as a fuel gas, as a result, part of the gasoline fraction (C5C6) with the fatty gas is lost. In connection with the commissioning of the isomerization unit, it became possible to process this fraction into a high-octane component of gasoline. Therefore, the actual task was to extract the C5C6 fraction from the fatty gas.

In order to achieve this, it has been proposed to cool the gasoline/fatty gas mixture to 40 ° C in a plate heat exchanger, thereby absorbing the fatty gas with the gasoline of the distillation columns.

The purpose of this thesis is to increase the selection of straight-run gasoline fraction.

The calculation was performed in DESIGN II.

Mechanical part

This section presents the process calculation of the heat exchanger (Fig. 3.1) intended for after-cooling of the mixture of gasoline and fatty gas.

Calculation of flange connections was also carried out and selection of materials was made for the manufacture of the heat exchanger .

Conclusion

The purpose of the graduation qualification work is to retrofit the AVT-1 unit in order to reduce the components of gasoline with fatty gas..

In this diploma project, calculations were made for the tent furnace P1, rectification columns K1, K-2, air cooling devices KV1, KhV-2.

A plate heat exchanger was selected and calculated. Calculation of flows and process parameters of absorption units is also given.

Fatty gas of the AV1 unit, containing a maximum of about 30 wt%. C5 - C6 hydrocarbons (average C5 - C6 content - 15 wt%), currently used as fuel gas in the plant furnaces, or sent to the HFC plant. The C5 to C6 hydrocarbons are valuable components of the isomerization unit feed and require the introduction of an absorption process to recover them from the fatty gas. Fatty gas from separator E1a is proposed to be absorbed by gasoline from E1a and E-2. Cooling the gas-gasoline stream in the new cooler to 40 0C will ensure absorption of C5 - C6 hydrocarbons from the fatty gas by gasoline. Recovered C5 + hydrocarbons together with straight-run gasoline of AVT-1 unit will be sent to AVT-5 unit stabilization unit. The gas after absorption can be used as a fuel.

In the process of calculations, it turned out that when switching to a new scheme, the production of basic products will increase.

The consolidated calculation of capital and current costs associated with its implementation confirmed the economic feasibility of the innovations envisaged by the project .