Heating Systems, Plant and Control

by Day, Antony R.; Ratcliffe, Martin S.; Shepherd, Keith

• ISBN13: 9780632059379
• ISBN10: 0632059370
• Edition: 1st
• Format: Hardcover
• Copyright: 2003-05-16
• Publisher: Wiley-Blackwell

Summary

This new book will cover commercial and industrial heating systems, with an emphasis on applications and the modern demands of cost efficiency and energy conservation. It will give the building services engineer guidance on design and specification and will serve as a main reference for undergraduates in building services.

Author Biography

Tony Day BEng (Hons), PhD, CEng, MCIBSE, MInstE is a Senior Lecturer at South Bank University where he is course director of the MSc in Building Services Engineering. He specializes in evaluating energy use in buildings and also lectures in the wider context of energy and the environment. He has published a number of papers on building energy analysis, as well as the development of renewable energy systems. Before entering academia he was a Chief Engineer at a London hospital.

Martin Ratcliffe BSc (Hons), CEng, MCIBSE has been involved in building services for more than 25 years, working as a senior mechanical engineer at a large international consultancy and, for the last 14 years, Senior Lecturer and course director for Building Services at South Bank University. In this last role he has concentrated on teaching the holistic design of mechanical services with emphasis on performance and energy consumption and has been involved with recent CIBSE and BSRIA design guides.

Keith Shepherd BEng (Hons), MSc is a building services consultant. A graduate of the Institute of Environmental Engineering at London’s South Bank Polytechnic, where he gained first class honours in environmental engineering, he was awarded a Master of Science degree by research from UMIST. Author of a book VAV Air Conditioning Systems (also published by Blackwell) and several papers, his 22 years’ experience of building services encompasses design, project management, research, lecturing, estimating and quantity surveying.

Table of Contents

Introduction	1	(6)
Heating: the fundamental building service	1	(1)
Low-pressure hot water	1	(1)
The need for efficient heating systems	2	(1)
Scope of the book	3	(1)
Content of the book: an overview	3	(4)
PART A HEAT GENERATION	7	(156)
Boilers and Burners	9	(47)
Definition of a boiler	9	(1)
Principal functional elements of a boiler	9	(3)
Gas-fired boilers	9	(1)
Oil-fired boilers	10	(2)
Solid fuel boilers	12	(1)
The boiler block	12	(6)
Function of the boiler block	12	(1)
Configuration and design	12	(3)
The multi-pass principle	15	(1)
Water content and temperature differential	16	(2)
Wet-base and dry-base types	18	(1)
The burner	18	(21)
Function of the burner	18	(1)
Boiler fuels and the combustion process	18	(5)
Burner design	23	(2)
Atmospheric natural gas burners	25	(4)
Fan-assisted and forced-draught natural gas burners	29	(3)
Premix natural gas burners	32	(2)
Other natural gas burners	34	(1)
Burners for other gases	34	(2)
Pressure-jet oil burners	36	(2)
Other atomizing oil burners	38	(1)
Dual-fuel burners	39	(1)
Burner operation and control	39	(8)
Functions of burner control	39	(1)
Modes of control for burner output	40	(1)
On/off control of burner output	40	(5)
High/low/off control of burner output	45	(1)
Modulating control of burner output	45	(1)
Control of burner safety	46	(1)
The burner gas line	47	(2)
The boiler control system	49	(6)
Boiler controls and system controls	49	(1)
Control of the burner	50	(2)
Boiler safety and limit controls	52	(2)
Reporting functions: remote monitoring	54	(1)
The boiler casing	55	(1)
Types of Boiler and Their Needs	56	(57)
Types of boiler	56	(1)
Boiler construction materials	56	(3)
Range of materials	56	(1)
Cast-iron	56	(1)
Steel	57	(1)
Copper and aluminium	58	(1)
Methods of construction	59	(8)
Cast-iron sectional boilers	59	(2)
Fabricated steel boilers	61	(4)
Copper boilers	65	(2)
Fire-tube and water-tube boilers	67	(1)
Modular boiler installations	67	(5)
Types of modular boiler installation	67	(1)
Modular boiler systems	67	(2)
True modular boilers	69	(3)
Heating, hot water service and combined applications	72	(1)
Condensing operation	73	(14)
Principles and benefits	73	(5)
Requirements of condensing operation	78	(1)
Condensing boilers	79	(5)
Condensing economisers	84	(3)
Boiler efficiency	87	(5)
Choosing the correct definition	87	(1)
Basis of the definition	87	(1)
Gross and net calorific value	88	(1)
Overall efficiency	89	(1)
Combustion efficiency	90	(1)
Seasonal efficiency	91	(1)
Carbon intensity	92	(1)
The needs of the boiler installation	93	(1)
Hydraulic stability	93	(1)
Return water temperature	94	(1)
Pressure in the boiler circuit	94	(2)
Fuel supply	96	(9)
Natural gas	96	(3)
LPG	99	(1)
Oil	100	(5)
Ventilation of the boiler plant room	105	(3)
Water treatment	108	(5)
Alternative Means of Heat Generation	113	(24)
Scope of the alternatives	113	(1)
Combined heat and power units	113	(13)
The concept	113	(1)
Application to building services	114	(1)
Principal elements of a small-scale packaged CHP unit	114	(2)
Typical energy balance for a small-scale packaged CHP unit	116	(1)
Fuels for CHP	117	(2)
The economic case	119	(3)
The CHP unit as part of a boiler installation	122	(4)
Heat pumps	126	(9)
Principle of operation	126	(1)
Heat sources	126	(2)
Coefficient of performance	128	(1)
Refrigerants	129	(1)
Application to LPHW heating systems	130	(3)
Cost and environmental performance	133	(2)
Energy crops and bio-diesel	135	(1)
Waste as a fuel	136	(1)
Flueing	137	(26)
Purpose of the flue	137	(1)
Flue and chimney	137	(1)
Types of flue	138	(1)
Flue draught	138	(6)
Natural-draught flues	144	(1)
Mechanical-draught flues	144	(5)
Balanced flues	149	(4)
Flue dilution systems	153	(3)
Sizing of the flue	156	(3)
General design and construction of the flue	159	(2)
Flues for condensing boilers	161	(2)
PART B SYSTEMS AND CONTROL	163	(153)
Room Heat Emitters	165	(30)
Introduction	165	(1)
General description of heat emitter types	165	(7)
Natural convectors	165	(2)
Fan convectors	167	(1)
Radiators	168	(2)
Radiant panels	170	(1)
Heated floors	171	(1)
Typical heat output rates	172	(5)
Natural convectors	173	(1)
Fan convectors	174	(1)
Radiators and radiant panels	175	(2)
Heated floors	177	(1)
Effect on thermal comfort	177	(1)
Heat loss rate and energy consumption	178	(3)
Safety issues	181	(1)
Controlling heat output rate	181	(2)
Modulation of water flow rate	181	(1)
Flow temperature modulation	182	(1)
Combined flow rate and temperature modulation	183	(1)
Underfloor heating	183	(12)
Upward heat flow	183	(1)
Downward heat flow	184	(1)
Thermal capacitance	184	(2)
Appendix 6.1 Thermal Comfort	186	(3)
Appendix 6.2 Emitter Heat Output Rate Analysis	189	(6)
Heating Circuits	195	(32)
Choice of flow and return water temperatures	195	(1)
Insulation of pipework	196	(3)
Economic insulation thickness	197	(1)
Environmental considerations	198	(1)
Other considerations	198	(1)
Pipework arrangements	199	(2)
Secondary circuit	200	(1)
Compensated temperature circuit	201	(1)
Variable volume flow	201	(8)
Variable volume pumping	203	(1)
Variable speed drives	204	(1)
Control of variable speed pumps	205	(4)
Control valves	209	(4)
Valve inherent characteristic	211	(1)
Installed characteristic	212	(1)
Recommended valve authorities	213	(1)
Forces acting on pipework	213	(14)
Types of support	215	(1)
Spacing of supports	215	(1)
Expansion and contraction	216	(2)
Forces arising from the fluid	218	(2)
Appendix 7.1 Heat Loss from Pipework	220	(3)
Appendix 7.2 Idealised Pump Characteristics	223	(2)
Appendix 7.3 Forces Due to Fluid Flow	225	(2)
Hot Water Services	227	(20)
Instantaneous versus storage	227	(1)
Central versus local systems	228	(1)
Sizing	229	(4)
Peak instantaneous demand	229	(2)
Time-averaged demand	231	(1)
CIBSE sizing charts for storage systems	232	(1)
Systems	233	(6)
Domestic storage systems	233	(2)
Non-domestic storage system	235	(2)
Unvented systems	237	(1)
Pumped storage	237	(1)
Hot water generators	238	(1)
Instantaneous	239	(1)
Solar hot water	239	(3)
Integration with HWS system	239	(1)
Efficiency and output of panel	240	(2)
Sizing of the system	242	(1)
Legionella	242	(5)
Appendix 8.1 Solar Panel Efficiency	244	(3)
Sizing Central Boiler Plant	247	(20)
Design heat output	247	(2)
Traditional sizing approaches	249	(12)
CIBSE guidance	249	(1)
Plant size and intermittent operation	250	(5)
An economic approach to sizing	255	(6)
Optimum start control	261	(6)
Optimum start and compensator interaction	265	(1)
Optimum stop	265	(2)
Matching Output to Demand	267	(28)
Relationship between heating demand, system sizing and boiler capacity	267	(2)
Boiler efficiency	267	(2)
System seasonal efficiency	269	(1)
Designing the central plant arrangement	269	(3)
Plant configuration	270	(2)
System configuration	272	(7)
Weather compensation control	272	(2)
Calculating room and emitter temperatures for practical schedules	274	(4)
The implications of compensator control for the central plant	278	(1)
Primary ring main	279	(1)
Controlling boiler output	280	(15)
Temperature sensing	281	(1)
Single boiler with flow sensing	281	(3)
Multiple units with common header	284	(1)
Sequencing	285	(1)
Common flow temperature control	286	(1)
Temperature dilution effects	287	(1)
Flow prevention through unfired boilers	287	(1)
Injection systems	288	(1)
Large systems with cascade control or heat metering	289	(1)
Heat metering	290	(1)
High/low firing	291	(1)
Multiple units with modulating burners	291	(1)
Condensing boilers	292	(1)
Anti-cycling and add-on devices	292	(3)
Energy Consumption of Heating Systems	295	(21)
Degree-day based estimates	295	(12)
Calculating degree-days	297	(1)
Calculation errors	298	(2)
Base temperature correction	300	(1)
Application of degree-days	300	(4)
Uncertainty	304	(3)
Monitoring and targeting of existing systems	307	(4)
Performance lines	307	(1)
Scatter in the performance line	308	(1)
Applying the performance line	309	(1)
Base temperature and the performance line	309	(2)
Benchmarking	311	(1)
Normalisation	312	(1)
Minimising energy use in heating systems	313	(3)
Design	313	(1)
Hot Water Services (HWS)	314	(1)
Management	314	(2)
Index	316