LCH Systems Description

Transas is a registered trademark Transas Marine Ltd. March, 2002 of Transas Marine Ltd. in Great Britain and other jurisdictions.

Complied by: D.V.Kazunin, Ph.D A.V.Kozhevnikov, Ph.D

LCHS CHEMICAL/PRODUCT TANKER

SYSTEMS DESCRIPTION

The information contained herein is proprietary LCHS CHEMICAL/PRODUCT TANKER. to Transas Marine Ltd. and shall not be duplicated Systems Description. or used in whole or part for any purposes whatsoever.

CONTENTS INTRODUCTION................................................................................................ V

Purpose ....................................................................................................... V 1. BALLAST SYSTEM .................................................................................. 1-1

1.1 Purpose ............................................................................................ 1-1 1.2 System Components ........................................................................ 1-1 1.3 Controls ............................................................................................ 1-2 1.4 Monitored Parameters, Indicators..................................................... 1-2 1.5 Alarms .............................................................................................. 1-2 1.6 Protection ......................................................................................... 1-4 1.7 Principal Possible Faults (Troubleshooting) ..................................... 1-4 1.8 Emergency Stop of Exercise Conduct .............................................. 1-4

2. CARGO HANDLING SYSTEM ................................................................. 2-5 2.1 Purpose ............................................................................................ 2-5 2.2 System Components ........................................................................ 2-5 2.3 Controls ............................................................................................ 2-6 2.4 Indicators.......................................................................................... 2-6

2.4.1 Alarms.................................................................................. 2-9 2.4.2 Protection............................................................................. 2-9 2.4.3 Principal Faults .................................................................... 2-9

2.5 Emergency Termination of the Exercise Conduct ............................ 2-9 3. STRIPPING SYSTEM............................................................................. 3-11

3.1 Purpose .......................................................................................... 3-11 3.2 System Components ...................................................................... 3-11 3.3 Controls .......................................................................................... 3-12 3.4 Indicators........................................................................................ 3-12

CONTENTS

The information contained herein is proprietary to Transas Marine Ltd. and shall not be duplicated

or used in whole or part for any purposes whatsoever.

II

3.5 Alarms ............................................................................................ 3-12 3.6 Protection ....................................................................................... 3-12 3.7 Principal Faults............................................................................... 3-12 3.8 Emergency Termination of the Exercise Conduct .......................... 3-12

4. TANK WASHING SYSTEM .................................................................... 4-13 4.1 Purpose .......................................................................................... 4-13 4.2 System Components ...................................................................... 4-13 4.3 Controls .......................................................................................... 4-14 4.4 Indicators........................................................................................ 4-14 4.5 Alarms ............................................................................................ 4-15 4.6 Protection ....................................................................................... 4-15 4.7 Principal Faults............................................................................... 4-15 4.8 Emergency Termination of Exercises ............................................. 4-15

5. OIL DISCHARGE MONITORING AND CONTROL SYSTEM................. 5-17 5.1 Purpose .......................................................................................... 5-17 5.2 System Components ...................................................................... 5-17 5.3 Controls .......................................................................................... 5-18 5.4 Monitored Parameters .................................................................... 5-18 5.5 Alarms and Stopping of the Discharge ........................................... 5-18 5.6 Protection ....................................................................................... 5-19 5.7 Principal Faults............................................................................... 5-19 5.8 Emergency Termination of the Exercise......................................... 5-19

6. INERT GAS SYSTEM............................................................................. 6-21 6.1 Purpose .......................................................................................... 6-21 6.2 System Components ...................................................................... 6-21 6.3 Controls .......................................................................................... 6-22 6.4 Monitored Parameters .................................................................... 6-25 6.5 Alarms ............................................................................................ 6-25 6.6 Protection ....................................................................................... 6-26 6.7 Principal Possible Faults ................................................................ 6-26 6.8 Emergency Termination of the Exercise......................................... 6-27

7. CARGO HEATING SYSTEM .................................................................. 7-29 7.1 Purpose .......................................................................................... 7-29 7.2 System Components ...................................................................... 7-29 7.3 Controls .......................................................................................... 7-30 7.4 Monitored Parameters .................................................................... 7-30

CONTENTS


III

7.5 Alarms ............................................................................................ 7-30 7.6 Protection ....................................................................................... 7-30 7.7 Principal Possible Faults ................................................................ 7-30 7.8 Emergency Termination of Exercises ............................................. 7-30


INTRODUCTION

PURPOSE The Liquid Cargo Handling Simulator (Chemical Tanker) is intended for the trai-ning and practicing of tanker personnel in the functions associated with the control of cargo handling and other operations in compliance with requirements of STCW-95, MARPOL 73/78 and other international conventions. The general description of systems provided in this document serves as the ba-sis for familiarisation with the simulator structure and can be used for studying the tanker systems within the framework of standard IMO courses: IMO 2.06 Cargo and Ballast Handling Simulator and IMO 1.03 Chemical Tanker Fami-liarization, 1.04 Advanced Tanker Program on Chemical Tanker Operations. For a prototype a Product/Chemical tanker for carrying cargoes was selected; its deadweight is 8.000 tons, length overall is 109 m, breadth is 18.6 m, hull height is 10 m. The tanker has been built in compliance with all the current regulations. Ballast ranks are used exclusively for receiving clean ballast and form a protecting skin around the cargo tanks. Cargo spaces are divided into the portside and starboard side tanks to reduce the cargos free surface. The ship framing is removed to the ballast tanks enab-ling a free running down of cargo along the smooth surface of tank walls. Star-board and portside tanks form an isolated group for carrying a single grade of cargo. Suction wells are located In the middle of the tanks after part. The cargo is pumped from the wells by using the immersed electric driven pumps.

INTRODUCTION



VI

Tonnage and dimensions

Deadweight:

Length overall:

Length b.p.:

Breadth moulded:

Depth moulded

Summer load line draft

Cargo capacities and facilities:

Cargo l (including slops)

Water ballast

8,000 t

109.0 m

102.0 m

18.6 m

8.12 m

7.65 m

8.320 m3

2,960 m3

Cargo handling: 12 electric driven cargo pumps, 200 m3/h each against total head of 12bar

Selfstripping system.

Two electric driven ballast pumps, 250 m3/h of sea water each.

To generate an inert environment in the gas spaces of cargo tanks, Inert Gas System is provided on board the ship. For an inert gas either nitrogen or carbon dioxide are used. Cargo vapours can be removed into the atmosphere or discharged onto the shore via pipelines. Installed on board the tanker there is equipment which allows performing tank jet washing operations. Tank washing is done for clearing the tanks surfaces of sedimentation before accepting another grade of cargo in order to prevent them from entering into reaction. In addition, this allows extending the tank coating service life. The washing pump and ballast pumps are located in a special pump room under the forward part of the ship superstructure. The pump room is isolated from the engine room. In the top part of the pump room well the washing water heater is installed. All the tanker systems are implemented as a linear structure. The tanker sys-tems are considered below.


1. BALLAST SYSTEM

1.1 PURPOSE The system is designed for the reception and pumping out of clean ballast from the tanks. The system is used to ensure the ship trim and stability in order to maintain its seaworthiness and admissible stresses on the hull.

1.2 SYSTEM COMPONENTS The clean ballast system consists of (as shown in the drawing Ballast System): Ballast tanks:

five portside tanks B1P253 m3, B2P-301 m3, B3P325 m3, B4P- 317 m3, B5P 377 m3;

five starboard tanks B1S 239 m3, B2S-301 m3, B3S-305 m3, B4S 317 m3, B5S 348 m3;

forepeak tank BFP 151 m3. The tanks communicate with ballast lines via connection pipes, and with the atmosphere via the venting pipe.

Two centrifugal pumps Bp1 and Bp2, each with a capacity of Q=250 m3/h, at P3 bars. Pumps have self-priming systems Bstr1, Bstr2;

Centrifugal fire pump Bp3 included in the system for filling the forepeak tank with a discharge of Q=80 m3/h, at 8 bars. The pump is fitted out with self priming system Bstr3;

Three sea chests Bch1, Bch2 and Bch3 with strainers; Systems cut-off valves Bv1Bv13;

BALLAST SYSTEM



1-2

Tanks throttle valves (Bv1s.Bv5s), (Bv1p.Bv5p) and BvFp. For throttle valves the system uses butterfly valves whose position is determined by the valves clear opening;

Three discharge non-return valves Bv14, Bv15 and Bv16.

1.3 CONTROLS Control of cut-off valves (Bv1Bv13); Control of non-return valves Bv14, Bv15 and Bv16; Pumps ON/OFF buttons; Control of tanks throttle valves (Bv1sBv5s), (Bv1pBv5p) and BvFp; Pumps self-priming systems Bstr1, Bstr2, Bstr3.

1.4 MONITORED PARAMETERS, INDICATORS Ballast level indicator for the tanks (B1S.B5S), (B1P...B5P). Indicators are

located at the aft bulkhead and show levels in their installation points; Bp1, Bp2 and Bp3 pumps ON indicator; Bp1, Bp2 and Bp3 pumps charging pressure, suction vacuum; ON indicator of pumps self-priming systems Bstr1, Bstr2, Bstr3; Indicators of the systems cut-off valves Bv1Bv12; Indicators of the throttle valves positions (Bv1sBv5s), (Bv1p...Bv5p) on the

tanks (B1SB5S), (B1P...B5P).

1.5 ALARMS Levels in ballast tanks (B1P...B5P), (B1SB5S):

level of more than 95 per cent; level of less than 5 per cent.

No response from the throttle valve to the change of setting for 10 se.

Fi

g. 1

Bal

last

Sys

tem

BALLAST SYSTEM



1-4

1.6 PROTECTION The pump is turned off to protect it from overheating.

1.7 PRINCIPAL POSSIBLE FAULTS (TROUBLESHOOTING) Valves do not operate due to the hydraulic system fault; Faults in individual hydraulic drives of valves; Fouling of sea chest strainer; Fault in self-priming systems (no vacuum in the self-priming system); Pump emergency stop to protect it from overheating.

1.8 EMERGENCY STOP OF EXERCISE CONDUCT For the training purposes, exercises are stopped if ballast tanks are filled to more than 100 per cent of their capacity, as there is as there may be tank compression. In practice, the filling as high as the venting pipe is actually used and requires high proficiency and considerable experience in the system ope-ration. Therefore, to establish operating discipline in the trainees, the simulator includes a function for stopping the exercise in case of the tank overpressure.


2. CARGO HANDLING SYSTEM

2.1 PURPOSE The cargo handling system serves for charging, transfer and discharging of six grades of oil and chemical products in/from the cargo and settling tanks. The system is also used for the tank stripping and washing process.

2.2 SYSTEM COMPONENTS The cargo handling system is implemented in accordance with the autonomous/ group principle. The portside and starboard tanks within the water proof com-partments are combined to form six groups. The system includes the following components (see Fig. Cargo Handling System): Cargo tanks:

six portside tanks: C1P 569 m3, C2P 865 m3, C3P 888 m3, C4P 888 m3, C5P 840 m3, C6P 110 m3;

six starboard tanks: C1S, C2S, C3S, C4S, C5S, C6S. Tank capacities are equal to those of their corresponding portside tanks.

Tanks are fitted out with special venting devices (described below). Ten electric driven centrifugal immersed pumps Cp1pCp5s, installed in

tanks 1P,S 5P,S. Each pumps discharge is Q=200 m3/h at P~ 12 bars; Two electric driven centrifugal immersed pumps Cp6p, p6s installed in

tanks 6P,S. Each tanks discharge is Q=100 m3/h at P~ 12 bars. The ships electric power station allows a simultaneous use of 5 pumps only. There is a facility enabling all the cargo pumps to be stopped simultaneously;

Cut-off valves on the communication of portside manifolds Cv1pLCv6pL and starboard manifolds Cv1sLCv6sL with onshore pipelines;

Cut-off valves on the connection pipe between cargo lines CvsL and CvpL;

CARGO HANDLING SYSTEM



2-6

Cut-off valves on drop line (Cv1s2Cv6s2) and (Cv1p2Cv6p2); Throttle valves on the charging line on pumps (Cv1s1Cv6s1) and

(Cv1p1Cv6p1); Pipelines for the distribution of cargo among the tanks; Cut-off valves Slop1Slop6 for filling slop tank C6P through valve Wv9 and

for communicating with the washing system via valve Wv4.

2.3 CONTROLS System controls are shown on Cargo Handling System mnemonic diagram: Cut-off valves on drop line (Cv1s2Cv6s2) and (Cv1p2Cv6p2); Throttle valves on the charging line of pumps (Cv1s1Cv6s1) and

(Cv1p1Cv6p1); ON/OFF of cargo pumps Cp1pCp6p and Cp1sCp6s; Cut-off valves Slop1Slop6, Wv9, Wv4 for communicating with the washing

system; Cargo charging, discharging and distribution cut off valves Cv10Cv25.

2.4 INDICATORS Pumps Cp1pCp6p and Cp1sCp6s ON indicator; Cargo pumps charging pressure; Current in the windings of the cargo pump drives electric motor; Indicators of the throttle valves open position; Cargo level and density in the tanks; Cargo temperatures in the tanks: at two height levels and average tempera-

ture in the tank; Rate of cargo delivery into the tanks; Gas pressure in the tanks; Pressure in cargo lines Cg1LCg6L before the outlet to shore manifolds.

Fi

g. 2

Car

go H

andl

ing

Syst

em (a

ft)

Fi

g. 3

Car

go H

andl

ing

Syst

em (f

ore)

EMERGENCY TERMINATION OF THE EXERCISE CONDUCT


2-9

2.4.1 ALARMS High level of cargo in the tanks:

alert at 95 per cent filling; emergency alarm at 98 per cent filling.

Temperature or cargo in the tanks: lowest permissible value; highest permissible value.

High current in the electric motor windings; Low current in the electric motor windings (to prevent the shaft bearings

from operating in the conditions of no lubrication); High pressure in the cargo lines.

2.4.2 PROTECTION Cargo pumps are stopped automatically in the following cases: Faults in the Inert Gas System (IGS); High current in the electric motor windings; Low current in the electric motor windings (to prevent the sliding bearings

from operating in the conditions of no lubrication). All the pumps can be stopped simultaneously from the cargo control room or cargo post in the area of the cargo manifold.

2.4.3 PRINCIPAL FAULTS Leakage in pipelines or valves; Faults in cut-off and throttle valves; Cargo pump break-down; No cargo suction from the tank: non-return valve sticking or damaged hyd-

raulic tightness of the pump head.

2.5 EMERGENCY TERMINATION OF THE EXERCISE CONDUCT For the training purposes, exercises are terminated in the following cases: filling of cargo tanks to more than 100 per cent of their capacity, as there is

overflowing of cargo; mixing of different grades of cargo in the tanks; pressure growth in the cargo lines to more than 1.5 of the rated value.


3. STRIPPING SYSTEM

3.1 PURPOSE The Stripping System is designed for: pumping out cargo residue from the pipelines of the Cargo Handling System; pumping out cargo residue from the pump casings and cargo wells onto the

shore or in the slop tanks. The major tank stripping is effected by the cargo pumps at a reduced rate of revolutions with the use of adjustable valves on the charging line. After the cargo pumps are stopped, cargo residue is removed from the charging pipes and wells by using special reciprocating pumps.

3.2 SYSTEM COMPONENTS The system includes: Cargo tanks C1p, SC6P, S; Cargo Handling System lines with valves; 10 reciprocating pumps Cps1p,sCps5p,s with a pneumatic drive. Each

pump has a discharge of 6 m3/h with a head of approximately 60 m and the piston moving at a rate of 13 strokes/min;

10 cut-off valves Cv1s3, Cv1p3Cv5s3, Cv5p3 connecting the deck cargo lines with the charging line of reciprocating pumps Cps1p, sCps6p, s;

Small diameter pipeline for draining into slop tank C6P through valves Slop16 or discharging onto the shore via line 6 through valves Cv6pL and Cv6sL.

STRIPPING SYSTEM



3-12

3.3 CONTROLS The principal system controls are shown in Fig. Cargo Handling System. Cut-off valves Cv1s3,Cv1p3Cv6s3,Cv6p3; Start/Stop of stripping pumps Cps1p,sCps6p,s.

3.4 INDICATORS ON indicator of pumps Cps1p, s.Cps6p, s; Position of cut-off valves Cv1s3, Cv1p3.Cv6s3, Cv6p3; Levels in the wells of tanks C1P, S.C6P, S; Charging pressure of pumps Cps1p, s.Cps6p, s.

3.5 ALARMS Not provided.

3.6 PROTECTION To protection is provided.

3.7 PRINCIPAL FAULTS Failure of valves Cv1s3, Cv1p3Cv6s3, Cv6p3. Failure of drives of stripping pumps Cps1p, sCps6p, s.

3.8 EMERGENCY TERMINATION OF THE EXERCISE CONDUCT The exercise is terminated if a reciprocating pump is started with valves closed on the charging line.


4. TANK WASHING SYSTEM

4.1 PURPOSE Chemical tankers are fitted out with a tank washing system. This system enables the tank surfaces to be cleared of cargo residue by using jets of washing fluid. For a better cleaning process, washing fluid can be heated. The tank washing system is used for feeding washing fluid to the stationary washing machines. The washing fluid is removed from tanks with the immersed cargo pumps of these tanks using the cargo handling system pipelines.

4.2 SYSTEM COMPONENTS The following equipment should be listed as the systems principal equipment: Washing system deck pipelines (see Fig. 4); Electric driven centrifugal washing pump Wp1. Pump capacity is Q~70 m3/h

at a head of 10 bars; Two centrifugal pumps of slop tanks in Cp6s and Cp6p which are part of the

Cargo Handling System; 12 washing machines (Wm1p Wm6p) and (Wm1s Wm6s) which the

washing fluid is fed to through the pipelines from pumps Wp1, Cp6s, Cp6p or from the cargo lines through valve Wv4 Cargo Line connection valve. From the slop tank pumps the washing fluid is fed through valve Slop6, and from the cargo pumps through valves Slop15 respectively. The operating flow through each washing machine is Q~25 m3/h at a pressure of P~10 bars. Fixed in the top part of each tank is a washing machine rotated by the washing fluid flow;

Washing water heater Wh1 with a capacity of 100 m3/h which provides the outlet temperature of 80. Water temperature at the outlet is changed by means of by-passing by using throttle valve Wv11;

TANK WASHING SYSTEM



4-14

Cut-off valves of washing machines (Wv1p Wv6p) and (Wv1s Wv6s) wherethrough the washing fluid is fed to the washing machines;

Throttle valves (Wv1m Wv6m) which are sued for varying the washing pressure for the portside and starboard tanks machines;

Sea chest Bch2 which is part of the Ballast System; Drained ODME water check tools. In the mode of discharging water over-

board, control of the cut-off valves Wv12 and Wv13 is effected automatically. If there is no discharging of water, the valves are controlled manually from the mnemonic diagram;

Cut-off valves Wv1 Wv3 and Wv5 Wv9 for the system control; Throttle valve Wp10 which serves for changing the capacity of washing

pump Wp1; Washing agent can be delivered to the system from cargo pumps

Cp1p,s5p, s through pipeline From Cp15.

4.3 CONTROLS The principal controls are shown in Fig. 4: Throttle valves (Wv1m Wv6m), Wv10, Wv11; Cut-off valves (Wv1p Wv6p), (Wv1s Wv6s), (Wv1 Wv9) and Wv12,

Wv13, Wv14; The Washing System communicates with the Cargo Handling System via

valve Wv4 (Cargo Line Connection valve). The washing fluid is fed from the slop pumps through valve Slop6 on the Washing System. From cargo pumps Cp1Cp5 the washing fluid is fed through pipeline From Cp15 on the Washing System and through valves Slop15 on the Cargo Handling System.

Controls available on the system objects control panels are the following:: Start/Stop of washing pump Wp1; Start/Stop of pumps Cp6p and Cp6s; Washing mode programmer for each washing machine: machines washing

angle and rate of rotation, number of cycles.

4.4 INDICATORS Suction and charging pressure of pump Wp1; On indicator of pump Wp1; Charging pressure of pumps Cp6p and Cp6s; Current in the electric motor windings of pumps Cp6p and Cp6s; On indicator of pumps Cp6p and Cp6s;

ALARMS


4-15

Water temperature before Wg8 and after Wg7 of Wh1 heater; ON indicator of Wh1 heater; Pressures of Wg1Wg6 in each group of washing machines in a single

tank; Deck ON indicator of each washing machine: Wm1p,sWm6p, s; Indicators of cleanliness on surfaces of tanks C1P, SC6P, S; ON indicators of ODME and automatic control of valves Wv12, Wv13.

4.5 ALARMS Low pressure of the washing fluid before the washing machine; High current in the windings of electric motors Cp6p Cp6s; Low current in the electric motor windings (to prevent the shaft slide bea-

rings from operating in the conditions of no lubrication with the cargo) Cp6p Cp6s.

4.6 PROTECTION The washing process is stopped if the oxygen content in the tank is more than 8% of its volume, or in case of an cargo spill.

4.7 PRINCIPAL FAULTS Breakdown of the washing machine drive; Choking of the machine monitor nozzles.

4.8 EMERGENCY TERMINATION OF EXERCISES The exercise is terminated when the washing rules are violated (deviation of technology or mixing of incompatible agents).

Fi

g. 4

Tan

k W

ashi

ng S

yste

m


5. OIL DISCHARGE MONITORING AND CONTROL SYSTEM

5.1 PURPOSE The system is installed on the tanker in accordance with requirements of MARPOL 73/78 and IMO Resolution A.586(XIV). It serves for purifying the washing water to the admissible oil content and discharging it overboard, the oil content continuously monitored. The system of slop tanks allows the liquid to be collected, stored and purified by the settling method in the process of tank washing. In addition, there is a facility for discharging used washing fluid from the slop tanks to the shore.

5.2 SYSTEM COMPONENTS The system consists of (see Fig. 4): Slop tanks C6P, C6S where the petroleum products are settled by gravita-

tion, and the oily water is subjected to preliminary purification. Dirty washing fluid from the cargo tanks is fed through valve Wv9 to the first stage of clarification: in slop tank C6P. In this tank the water is collected and settled in the bottom part. From the bottom part of the tank the purified water is pressed out into slop tank C6S through the overflow pipe and valve Wv8. The secondary settling (second stage of purification) takes place here;

Cut-off valve Wv8 which links the first and second stages of slop tanks. The flow of liquid through the overflow pipe is limited with the value of 0.1 m/s;

Centrifugal washing pump Wp1 which pumps out overboard the water settled at the second stage. The pump can pump out the slop tank contents onto the shore through cargo line 6;

Cut-off non-return valve Wv13 for discharging oily water overboard. Dis-charging is effected over water line;

OIL DISCHARGE MONITORING AND CONTROL SYSTEM



5-18

Cut-off non-return valve Wv14 for discharging the chemical cargo residue overboard. The discharging is effected into the bilge;

Automatic Oil Discharge Monitoring Equipment (ODME) which is used for measuring oil content (instant and summary) in the water discharged over-board. The Oil Discharge Monitoring System (ODMS) received information from the log, flow meter and the sampler. In the automatic mode the monitor controls the valves: Wv13 for discharging the water overboard and Wv12 for discharging into the slop tank (see Fig.5).

5.3 CONTROLS The left had part of the screen (see Fig.5) displays uncontrolled mnemonic diagram of the system for purifying and discharging oily water. Control of the system elements is from the Tank Washing System screen. The right hand part of the screen (see Fig.5) displays a control panel with the following controls: Handle for switching the monitor to the manual/automatic discharging or tes-

ting mode; Buttons for selecting the scale of the automatic recorder tape and oily water

indicator scale; STOP button of the oily water discharge overboard; Calibration button; Sampling pump START button.

5.4 MONITORED PARAMETERS Levels in slop tanks C6P and C6S; Oil film thickness along oil/water interface detector in slop tanks imitates

operation of the shipboard medium separation equipment; Flow rate of the oily water discharged overboard; Oil content in the discharged water (PPM); Total amount of discharged oil product (m3); Intensity of the oil product discharge per mile covered by the ship (l/m); ON indicator of power supply to ODME system.

5.5 ALARMS AND STOPPING OF THE DISCHARGE High oil content in the water discharged overboard; In case of system faults; in case the rules of oily water discharge are not observed; In case of a high level in the second stage of slop tank C6S.

PROTECTION


5-19

5.6 PROTECTION Not provided.

5.7 PRINCIPAL FAULTS Broken valves Wv12, Wv13; Error in the ODME equipment calibrating.

5.8 EMERGENCY TERMINATION OF THE EXERCISE The exercise is terminated if the oily water and cargo discharge conditions are not observed.

Fi

g.5

OD

ME

Syst

em


6. INERT GAS SYSTEM

6.1 PURPOSE Inert Gas System generates cooled inert gas to fill the space over the cargo. This rules out the ignition of the carried cargo vapours. For the inert gas the system uses the generated carbon dioxide (2) or N2 stored in the cylinders. In addition, the system is used for ventilating tanks with air before the repairs and maintenance works.

6.2 SYSTEM COMPONENTS The system includes the following elements (see Fig. 6): Gear type fuel pumps Ipf1 and Ipf2. The fuel pressure is controlled by re-

cycle valve Iv7. The pumps taken out of operation are cut off by valves Iv19, Iv21and Iv20, Iv22;

Gas generator (burner/scrubber); Air blowers Ib1,Ib2. They suck in air from the atmosphere and feed it to the

burner through cut-off valves Iv18, Iv17; Controls of the gas generator burner: Burning Control. The unit controls

automatically throttle valves Iv4, Iv7. Throttle valve Iv4 sets the gas flow through the gas generator;

Centrifugal pumps Ips1, Ips2 feed water through throttle valve Iv5 to the Gas Generator Cooling System and to the irrigation of hot burner gases. Pumps taken out of operation are cut off with valves Iv14, Iv12 and Iv15, Iv13;

Cut-off valve Iv27 for maintaining permanent water level in the gas generator;

Nitrogen storage cylinders. Inert gas from the cylinders is fed via cut-off valves Iv24, Iv25 and throttle valve Iv6 into the system;

INERT GAS SYSTEM



6-22

uto/anual control of feeding inert gas to the tanks through valve Iv2 or discharging it into the atmosphere through valve Iv3: in uto mode the control unit receives information and automatically

controls throttle valves Iv2 and Iv3; in anual mode throttle valves Iv2 and Iv3 are controlled arbitrarily.

Deck water seal: Deck seal. Water in the seal is heated by feeding vapour through cut-off valve Iv23;

Centrifugal pumps Ips3, Ips4 supply water into the Deck seal. The level height in the seal does not rise above the overflow pipe;

Non-return valve Iv1 for feeding gas to the deck line (see Fig. 7); Valves for feeding inert gas into starboard tanks Iv1sIv6s and portside

tanks Iv1pIv6p; Automatic throttle valves on tanks Ia1p, s..Ia6p, s; Vapoure line: a line for discharging vapour from the tanks onto the shore

through valves IvpL, IvsL; Common P/V-breaker.

6.3 CONTROLS 1. Gas generator BURNING CONTROL is used for:

selecting the mode of starting the generator (stop/manual/automatic); selecting the operating mode: manual/automatic; controlling the gas generator output. This is done by manipulating the

valve: Iv7 valve for controlling the fuel feed into the gas generator; Iv4 valve for controlling the gas flow through the gas generator.

emergency stop. 2. Fuel pumps Ipf1, Ipf2 START/STOP button. 3. Cut-off valves of fuel pumps Iv19, Iv21and Iv20, Iv22. 4. Start/Stop of gas generator and gas cooling pumps Ips1, Ips2. 5. Pressure control valve Iv5 and cut-off valves of cooling pumps Iv12, Iv14

and Iv13, Iv15. 6. Cut-off valve for maintaining constant cooling water level in gas generator

Iv26. 7. START/STOP buttons of pumps Ips3, Ips4 for feeding water into the water

seal. 8. Cut-off valves Iv8,Iv19 and Iv10,Iv11 for replenishing the water seal. 9. Cut-off valve Iv23 of vapour supply for heating water in the water seal in the

winter time.

Fi

g. 6

Ine

rt G

as G

ener

atio

n Sy

stem

Fi

g. 7

Sys

tem

for t

he In

ert G

as D

istr

ibut

ion

amon

g th

e Ta

nks

MONITORED PARAMETERS


6-25

10. Start/Stop button of air blowers Ib1 and Ib2. 11. Cut-off valves of air blowers Iv17, Iv18. 12. Throttle valve Iv6 and cut-off valves Iv24, Iv25 of the system for feeding

nitrogen in the tanks. 13. Throttle valves Iv2 and Iv3 of feeding gas into the tanks or discharging it into

the atmosphere. 14. Non-return cut-off valve Iv1. 15. Cut-off valves Iv1p, s..Iv6p, s for gas distribution among the tanks. 16. Automatic throttle valves Iva1p, s.Iva6p, s. 17. Cut-off valves of the systems connection with shore pipelines IvpL, IvsL.

6.4 MONITORED PARAMETERS 1. Flow of gases produced in the generator (BURNING CONTROL panel). 2. Colour of gases Smoke (BURNING CONTROL panel). 3. Fuel and air flow (BURNING CONTROL panel). 4. Water temperature and pressure at the gas generator inlet Ig5. 5. Temperature and cubic content of 2 in the gas at the gas generator outlet Ig3. 6. Water level in the gas generator Ig4. 7. Temperature and cubic content of 2 in the gas after water seal Ig1. 8. Water pressure at the inlet and sea water temperature and level in water

seal Ig2. 9. Charging and suction pressure of water seal replenishing pumps

10. Charging and suction pressure of the gas generator cooling pumps. 11. Charging pressure of air blowers. 12. Temperature and pressure (/vacuum) of gas in the tanks. 13. Cubic content of oxygen and cargo vapours in the tanks. 14. Antifreeze level in the deck P/V breaker. 15. Status of automatic deck valves Iva1p,s.Iva6p, s. 16. Pressure in the deck inert gas distribution line Ig.

6.5 ALARMS 1. High temperature of gases at the gas generator outlet Ig3 (burner/scrubber). 2. High cubic content of oxygen in gases at the gas generator outlet Ig3 (bur-

ner/scrubber). 3. High/low oxygen content (2) and gas pressure Ig1 after the water seal.

INERT GAS SYSTEM



6-26

4. Low water pressure at the gas generator inlet Ig5. 5. High water level in the gas generator Ig4. 6. (Low/high) water level, (high/low) water temperature, (low) pressure of char-

ging water into the water seal Ig4. 7. Level in the deck P/V breaker. 8. High: oxygen content, pressure, temperatures in the tank. 9. The alarm is generated in case of an emergency stop of burning process in

the gas generator.

6.6 PROTECTION 1. In case of high temperature Ig3 of gases at the gas generator outlet, fuel

pumps Ipf1,Ipf2, air blowers Ib1, Ib2 and cargo pumps are stopped. 2. In case of high cubic content of oxygen Ig3, valve Iv2 is closed, whilst valve

Iv3 is opened. 3. In case of high oxygen content (2) and gas pressure Ig1 after the water

seal, valve Iv2 is closed, whilst valve Iv3 is opened. 4. In case of a low (Low) gas pressure Ig1 after the water seal, all the cargo

pumps are stopped. 5. In case of a high water level Ig4 in the gas generator, fuel pumps Ipf1, Ipf2,

air blowers Ib1, Ib2 and cargo pumps are stopped. 6. In case of low pressure (BURNING CONTROL) of fuel and cooling water

Ig5, fuel pumps Ipf1, Ipf2, air blowers Ib1, Ib2 and cargo pumps are stopped. 7. On case of a low level in the water seal Ig2, valve Iv2 is closed whilst valve

Iv3 is opened. 8. In case of high/low (vacuum0 pressure in the tanks, cargo pumps are

stopped.

6.7 PRINCIPAL POSSIBLE FAULTS Breakdown and unstable operation of air blowers; burning stopped in the gas generator; inadequate fuel burning, high temperature of exhaust gases and high 2

content in them; breakdown and unstable operation of fuel pumps; breakdown and unstable operation of gas generator cooling pumps; breakdown and unstable operation of the water seal replenishment pumps; loss of antifreeze in the deck P/V breaker; breakdown and unstable operation of the tanks gas discharge devices.

EMERGENCY TERMINATION OF THE EXERCISE


6-27

6.8 EMERGENCY TERMINATION OF THE EXERCISE Fuel pumps started with the valves closed; Oxygen cubic content in the tank exceeds 8 per cent in the process of the

cargo handling operations.


7. CARGO HEATING SYSTEM

7.1 PURPOSE The Heating System served for maintaining or raising the cargo temperature at/to the value which permits it to be pumped through the pipelines, or which is set in the voyage task. The system is designed for heating the cargo and sedimentation tank, and the pump room drain tank.

7.2 SYSTEM COMPONENTS The heated heat transfer agent (oil) with parameters displayed on indicator Hg1 is fed into the deck line through the throttle valve Hv1. The cooled down heat transfer agent with parameters displayed on indicator Hg2 is let out through throttle valve Hv2. The system for heating cargo in the tanks consists of the following components: Deck heat transfer agent inlet (pressure of ~6 bars, temperature of ~ 75 -

84C) and outlet lines; Cargo heating coil pipes set in the bottom part of the cargo tanks and pump

room drain tank; Throttle valves for the distribution (Hv1iHv6i) and collection (Hv1oHv6o)

of the heat transfer agent among/from the tanks; Throttle valves Hvi and Hvo of the pump room drain tank heater; Cut-off valves of heat transfer agent feed to the portside (Hv1piHv6pi) and

(Hv1siHv6si) starboard tanks; Cut-off valves of heat transfer agent outlet from the portside

(Hv1poHv6po) and starboard (Hv1soHv6so) tanks.

CARGO HEATING SYSTEM



7-30

7.3 CONTROLS Throttle valve Hv1 of feeding the heat transfer agent to the distribution deck

line; Throttle valve of returning the heat transfer agent from the deck heat transfer

agent collection line Hv2; Throttle valve of the hat transfer agent distribution (Hv1iHv6i) and collec-

tion (Hv1oHv6o) among/from the tanks; Cut-off valves of the heat transfer agent feeding to the cargo heating coil

pipes in the portside (Hv1piHv6pi) and starboard tanks (Hv1siHv6si); Cut-off valves of the heat transfer agent return from the portside

(Hv1poHv6po) and starboard (Hv1soHv6so) cargo heating coil pipes.

7.4 MONITORED PARAMETERS 1. Status of cut-off valves. 2. Position of throttle valves. 3. There is stationary remote monitoring of the cargo temperature and cargo level

in the tanks (see Cargo Handling System) and in the Pump room drain tank. 4. Pressure and temperature in the heat transfer agent at the inlet Hg1 and

outlet Hg2.

7.5 ALARMS 1. High cargo temperature. 2. Low cargo temperature. 3. Low pressure.

7.6 PROTECTION No protection is provided.

7.7 PRINCIPAL POSSIBLE FAULTS 1. Low temperature of heat transfer agent. 2. High temperature of heat transfer agent. 3. Faulty system valves.

7.8 EMERGENCY TERMINATION OF EXERCISES This occurs in case of the cargo overheating or subcooling in the tanks.

Fi

g. 8

Car

go H

eatin

g Sy

stem

Date post:	25-Sep-2015
Category:	Documents
Upload:	bereza-ana
View:	221 times
Download:	3 times

LCH Systems Description

Documents