HP Generating Set User Manual

0 (0)

GENERATING SET INSTALLATION MANUAL

FOREWORD

This installation manual will guide you to the factors to be considered in the installation of your diesel generator system. It discusses location and mounting of the generating set; size of room; ventilation and air flow; engine cooling water supply or radiator location; exhaust outlet; fuel tank and fuel transfer system.

By following the suggestions in this installation manual, you will be able to plan an economical, efficient generating set installation with operating characteristics suitable to each particular application.

You can make you work easier by enlisting the aid of an FG Wilson Distributor when planning your generating set installation. Getting his advice early may save cost and avoid problems. He knows engines, electrical equipment, local laws and insurance regulations. With his help, you can be sure your generating set installation will fulfil your needs without unnecessary cost.

ii

TABLE OF CONTENTS

 

 

 

PAGE

1.

INSTALLATION FACTORS

1

2.

MOVING THE GENERATING SET

1

3.

GENERATING SET LOCATION

1

4.

GENERATING SET MOUNTING

2

5.

VENTILATION

3

6.

ENGINE EXHAUST

6

7.

EXHAUST SILENCING

9

8.

SOUND ATTENUATION

10

9.

ENGINE COOLING

10

10.

FUEL SUPPLY

13

11.

SELECTING FUELS FOR STANDBY DEPENDABILITY

18

12.

TABLES AND FORMULAS FOR ENGINEERING STANDBY

19

 

GENERATING SETS:

 

 

Table 1

Length Equivalents

19

 

Table 2

Area Equivalents

19

 

Table 3

Mass Equivalents

19

 

Table 4

Volume and Capacity Equivalents

20

 

Table 5

Conversions for Units of Speed

20

 

Table 6

Conversions of Units of Power

20

 

Table 7

Conversions for Measurements of Water

21

 

Table 8

Barometric Pressures and Boiling Points of Water at Various Altitudes

21

 

Table 9

Conversions of Units of Flow

22

 

Table 10

Conversions of Units of Pressure and Head

22

 

Table 11

Approximate Weights of Various Liquids

22

 

Table 12

Electrical Formulae

23

 

Table 13

kVA/kW Amperage at Various Voltages

24

 

Conversions of Centigrade and Fahrenheit

25

 

Fuel Consumption Formulas

25

 

Electrical Motor Horsepower

25

 

Piston Travel

 

25

 

Break Mean Effective Pressure

25

13.

GLOSSARY OF TERMS

26

ã Copyright 1997 by FG Wilson (Engineering) Ltd

All rights reserved. No part of the contents of this manual may be reproduced, photocopied or transmitted in any form without the express prior written permission of FG Wilson (Engineering) Ltd.

1. INSTALLATION FACTORS

Once the size of the generating set and the required associated control panel and switchgear have been established, plans for installation can be prepared.

Proper attention to mechanical and electrical engineering details will assure a satisfactory power system installation.

Factors to be considered in the installation of a generator are:

Access and maintenance location. Floor loading.

Vibration transmitted to building and equipment. Ventilation of room.

Engine exhaust piping and insulation. Noise reduction.

Method of engine cooling. Size and location of fuel tank.

Local, national or insurance regulations. Smoke and emissions requirements.

2. MOVING THE GENERATING SET

The generating set baseframe is specifically designed for ease of moving the set. Improper handling can seriously damage the generator and components.

Using a forklift,the generating set can be lifted or pushed/pulled by the baseframe. An optional "Oil Field Skid" provides fork lift pockets if the set will be regularly moved.

Never lift the generating set by attaching to the engine or alternator lifting lugs!

For lifting the generating set, lift points are provided on the baseframe. Shackles and chains of suitable length and lifting capacity must be used and a spreader bar is required to prevent damaging the set. See figure 2.1. An optional "single point lifting bale" is available if the generating set will be regularly moved by lifting.

3. GENERATING SET LOCATION

The set may be located in the basement or on another floor of the building, on a balcony, in a penthouse on the roof or even in a separate building. Usually it is located in the basement for economics and for convenience of operating personnel. The generator room should be large enough to provide adequate air circulation and plenty of working space around the engine and alternator.

If it is necessary to locate the generating set outside the building, it can be furnished enclosed in a housing and mounted on a skid or trailer. This type of assembly is also useful, whether located inside or outside the building, if the installation is temporary. For outside installation the housing is normally "weatherproof". This is necessary to prevent water from entering the alternator compartment if the generating set is to be exposed to rain accompanied by high winds.

FIG 2.1. PROPER LIFTING ARRANGEMENT

1

4.GENERATING SET MOUNTING

The generating set will be shipped assembled on a rigid base that precisely aligns the alternator and engine and needs merely to be set in place (on vibration isolation pads for larger sets) and levelled. See figure 4.1

4.1 Vibration Isolation

It is recommended that the generating set be mounted on vibration isolation pads to prevent the set from receiving or transmitting injurious or objectionable vibrations. Rubber isolation pads are used when small amounts of vibration transmission is acceptable. Steel springs in combination with rubber pads are used to combat both light and heavy vibrations. On smaller generating sets, these isolation pads should be located between the coupled engine/alternator feet and the baseframe. The baseframe is then securely attached to the floor. On larger sets the coupled engine/alternator should be rigidly connected to the baseframe with vibration isolation between the baseframe and floor. Other effects of engine vibration can be minimised by providing flexible connections between the engine and fuel lines, exhaust system, radiator air

discharge duct, conduit for control and power cables and other externally connected support systems.

4.2 Floor Loading

Floor loading depends on the total generating set weight (including fuel and water) and the number and size of isolator pads. With the baseframe mounted directly on the floor, the floor loading is:

Floor Loading =

Total Generating Set Weight

Area of Skids

With vibration isolation between the baseframe and the floor, if the load is equally distributed over all isolators, the floor loading is:

Floor Loading =

Total Generating Set Weight

Pad Area x Number of Pads

Thus, floor loading can be reduced by increasing the number of isolation pads.

If load is not equally distributed, the maximum floor pressure occurs under the pad supporting the greatest proportion of load (assuming all pads are the same size):

Max Floor Pressure =

Load on Heaviest Loaded Pa

Pad Area

FIG 4.1 REDUCING VIBRATION TRANSMISSION

2

5. VENTILATION

Any internal combustion engine requires a liberal supply of cool, clean air for combustion. If the air entering the engine intake is too warm or too thin, the engine may not produce its rated power.

Operation of the engine and alternator radiates heat into the room and raises the temperature of the room air. Therefore, ventilation of the generator room is necessary to limit room temperature rise and to make clean, cool intake air available to the engine.

When the engine is cooled by a set mounted radiator, the radiator fan must move large quantities of air through the radiator core. There must be enough temperature difference between the air and the water in the radiator to cool the water sufficiently before it re-circulates through the engine. The air temperature at the radiator inlet depends on the temperature rise of air flowing through the room from the room inlet ventilator. By drawing air into the room and expelling it outdoors through a discharge duct, the radiator fan helps to maintain room temperature in the desirable range.

In providing ventilation, the objective is to maintain the room air at a comfortable temperature that is cool enough for efficient operation and full available power, but it should not be so cold in winter that the room is uncomfortable or engine starting is difficult. Though providing adequate ventilation seldom poses serious problems, each installation should be analysed by both the distributor and the customer to make sure the ventilation provisions are satisfactory.

5.1 Circulation

Good ventilation requires adequate flow into and out of the room and free circulation within the room. Thus, the room should be of sufficient size to allow free circulation of air, so that temperatures are equalised and there are no pockets of stagnant air. See figure 5.1. The generating set should be located so that the engine intake draws air from the cooler part of the room. If there are two or more generating sets, avoid locating them so that air heated by the radiator of one set flows toward the engine intake or radiator fan of an adjacent set. See figure 5.2.

FIG 5.1 TYPICAL ARRANGEMENT FOR ADEQUATE AIR CIRCULATION AND VENTILATION

3

5.2 Ventilators

To bring in fresh air, there should be an inlet ventilator opening to the outside or at least an opening to another part of the building through which the required amount of air can enter. In smaller rooms, ducting may be used to bring air to the room or directly to the engine's air intake. In addition, an exit ventilator opening should be located on the opposite outside wall to exhaust warm air. See Figure 5.3.

Both the inlet and exit ventilators should have louvres for weather protection. These may be fixed but preferably should be movable in cold climates. For automatic starting generating sets, if the louvres are movable, they should be automatically operated and should be programmed to open immediately upon starting the engine.

FIG 5.2 TYPICAL ARRANGEMENT FOR PROPER VENTILATION WITH MULTIPLE GENERATING SETS

4

HP Generating Set User Manual

5.3 Inlet Ventilator Size

Before calculating the inlet ventilator size, it is necessary to take into account the radiator cooling air flow requirements and the fan static pressure available when the generating set is operating at its rated load. In standard room installations, the radiated heat is already taken into account in the radiator air flow.

For generator room installation with remote radiators, the room cooling airflow is calculated using the total heat radiation to the ambient air of the engine and alternator and any part of the exhaust system.

Engine and alternator cooling air requirements for FG Wilson generating sets when operating at rated power are shown on specification sheets. Exhaust system radiation depends on the length of pipe within the room, the type of insulation used and whether the silencer is located within the room or outside. It it usual to insulate the exhaust piping

and silencer so that heat radiation from this source may be neglected in calculating air flow required for room cooling.

After determining the required air flow into the room, calculate the size of inlet ventilator opening to be installed in the outside wall. The inlet ventilator must be large enough so that the negative flow restriction will not exceed a maximum of

10 mm (0.4 in) H2O. Restriction values of air filters, screens and louvres should be obtained from manufacturers of these items.

5.4 Exit Ventilator Size

Where the engine and room are cooled by a set mounted radiator, the exit ventilator must be large enough to exhaust all of the air flowing through the room, except the relatively small amount that enters the engine intake.

FIG 5.3 INLET AND EXIT VENTILATORS

5

6. ENGINE EXHAUST

Engine exhaust must be directed to the outside through a properly designed exhaust system that does not create excessive back pressure on the engine. A suitable exhaust silencer should be connected into the exhaust piping. Exhaust system components located within the engine room should be insulated to reduce heat radiation. The outer end of the pipe should be equipped with a rain cap or cut at 60° to the horizontal to prevent rain or snow from entering the exhaust system. If the building is equipped with a smoke detection system, the exhaust outlet should be positioned so it cannot set off the smoke detection alarm.

6.1 Exhaust Piping

For both installation economy and operating efficiency, engine location should make the exhaust piping as short as possible with minimum bends and restrictions. Usually the exhaust pipe extends through an outside wall of the building and continues up the outside of the wall to the roof. There should be a sleeve in the wall opening to absorb vibration and an expansion joint in the pipe to compensate for lengthways thermal expansion or contraction. See figure 6.1.

It is not normally recommended that the engine exhaust share a flue with a furnace or other equipment since there is danger that back pressure caused by one will adversely affect operation of the others. Such multiple use of a flue should be attempted only if it is not detrimental to performance of the engine or any other equipment sharing the common flue.

The exhaust can be directed into a special stack that also serves as the outlet for radiator discharge air and may be sound-insulated. The radiator discharge air enters below the exhaust gas inlet so that the rising radiator air mixes with the exhaust gas. See figures 6.2 and 6.3. The silencer may be located within the stack or in the room with its tail pipe extending through the stack and then outward. Air guide vanes should be installed in the stack to turn radiator discharge air flow upward and to reduce radiator fan air flow restriction, or the sound insulation lining may have a curved contour to direct air flow upward. For a generating set enclosed in a penthouse on the roof or in a separate outdoor enclosure or trailer, the exhaust and radiator discharges can flow together above the enclosure without a stack. Sometimes for this purpose the radiator is mounted horizontally and the fan is driven by an electric motor to discharge air vertically.

 

SILENCER/PIPEWORK

WALL SLEEVE

SUPPORTS

AND EXPANSION

 

JOINT

 

RAIN CAP

EXHAUST

SILENCER

 

FIG 6.1 TYPICAL EXHAUST SYSTEM INSTALLATION

6

6.2 Exhaust Pipe Flexible Section

A flexible connection between the manifold and the exhaust piping system should be used to prevent transmitting engine vibration to the piping and the building, and to isolate the engine and piping from forces due to thermal expansion, motion or weight of piping. A well designed flex section will permit operation with ± 13 mm (0.5 in) permanent displacement in any direction of either end of the section without damage. Not only must the section have the flexibility to compensate for a nominal amount of permanent mismatch between piping and manifold, but it must also yield readily to intermittent motion of the Generating Set on its vibration isolators in response to load changes. The flexible connector should be specified with the Generating Set.

6.3 Exhaust Pipe Insulation

No exposed parts of the exhaust system should be near wood or other inflammable material. Exhaust piping inside the building (and the silencer if mounted inside) should be covered with suitable insulation materials to protect personnel and to reduce room temperature. A sufficient layer of suitable insulating material surrounding the piping

and silencer and retained by a stainless steel or aluminium sheath may substantially reduce heat radiation to the room from the exhaust system.

An additional benefit of the insulation is that it provides sound attenuation to reduce noise in the room.

6.4Minimising Exhaust Flow Restriction

Free flow of exhaust gases through the pipe is essential to minimise exhaust back pressure. Excessive exhaust back pressure seriously affects engine horsepower output, durability and fuel consumption. Restricting the discharge of gases from the cylinder causes poor combustion and higher operating temperatures. The major design factors that may cause high back pressure are:

Exhaust pipe diameter too small

Exhaust pipe too long

Too many sharp bends in exhaust system

Exhaust silencer restriction too high

At certain critical lengths, standing pressure waves may cause high back pressure

FIG 6.2 HORIZONTALLY MOUNTED EXHAUST SILENCER

FIG 6.3 RADIATOR AIR DISCHARGING INTO

WITH EXHAUST PIPE AND RADIATOR AIR

SOUND-INSULATED STACK CONTAINING

UTILISING COMMON STACK

EXHAUST SILENCER

7

Loading...
+ 23 hidden pages