Refrigeration and air-conditioning

A. R. Trott, T C Welch9780750642194, 0-7506-4219-X

The use of refrigeration, either directly or as part of an air-conditioning system, is essential to almost every branch of industry.There is a need for practitioners to familiarise themselves with the general principles and methods of refrigeration and air conditioning, and the types of plant and operation currently in use.This book provides a comprehensive introduction to the principles and practice of refrigeration and air-conditioning for the uninitiated student and a general overview of the industry for the practitioner. The fundamentals of the subject are introduced without involving the reader too deeply in theory and the content is presented in a logical order.This fully revised and updated third edition has a new chapter on Refrigerants that deals with the many changes in this area over the last 10 years, including the phase out of CFC and HCFC refrigerants in line with Ozone depletion and Global Warming. New, replacement refrigerants are described, together with Codes of Practice introduced for maintenance and servicing of refrigeration plants. The increased use of Ammonia and Propane are included, with the relevant Health and Safety aspects, and the move towards Absorption refrigeration equipment as more environmentally friendly.This new edition of Refrigeration and Air Conditioning is a valuable reference source for practising engineers and essential reading for students.

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Table of contents :
Contents……Page 5
Preface……Page 7
1.2 Heat……Page 8
1.3 Boiling point……Page 10
1.4 General gas laws……Page 11
24.8 SensibleÒlatent ratio……Page 0
1.6 Heat transfer……Page 13
1.8 Two- phase heat transfer……Page 19
2.1 Basic vapour compression cycle……Page 21
2.2 Coefficient of performance……Page 22
2.4 Volumetric efficiency……Page 26
2.5 Multistage cycles……Page 28
2.6 Refrigerants for vapour compression cycles……Page 30
2.8 Absorption cycle……Page 31
2.10 Air cycle……Page 33
2.11 Thermoelectric cooling……Page 34
3.2 Ideal properties for a refrigerant……Page 35
3.3 Ozone depletion potential……Page 36
3.4 Global warming potential ( GWP)……Page 37
3.5 Ammonia and the hydrocarbons……Page 40
3.7 Lubricants……Page 41
3.8 Health and safety……Page 42
4.1 General……Page 43
4.2 Multicylinder compressors……Page 44
4.3 Valves……Page 45
4.4 Capacity reduction……Page 47
4.5 Cooling……Page 50
4.8 Shaft glands. Motors……Page 51
4.9 Hermetic drives……Page 52
4.10 Sliding and rotary vane compressors……Page 54
4.11 Screw compressors……Page 56
4.12 Scroll compressor……Page 58
4.13 Dynamic compressors……Page 59
4.14 Capacity ratings……Page 63
5.1 Oil specifications……Page 64
5.2 Oil separators……Page 65
5.3 Oil circulation……Page 66
5.4 Dry expansion circuit……Page 67
5.5 Contaminants in oil……Page 68
6.2 Heat to be removed……Page 70
6.3 Air- cooled condensers……Page 72
6.4 Water- cooled condensers……Page 74
6.6 Evaporative condensers……Page 77
6.7 Water treatment……Page 79
6.8 Rating and sizing of condensers……Page 82
6.9 Condenser maintenance……Page 83
6.10 Condenser fittings……Page 84
6.12 Winter operation……Page 85
6.13 Receivers……Page 86
6.14 Dry coolers……Page 88
7.3 Air cooling evaporators……Page 90
7.4 Liquid cooling evaporators……Page 91
7.6 Defrosting……Page 96
7.7 Condensate pumps……Page 99
8.3 Low- pressure float switches……Page 100
8.4 High- pressure float valve……Page 102
8.5 Thermostatic level control……Page 103
8.6 Expansion valves for dry expansion circuits……Page 104
8.7 External equalizer……Page 107
8.9 Electronic expansion valve……Page 108
8.10 Thermal electric expansion valve……Page 109
8.11 Capillary tube restrictor……Page 110
9.2 Thermostats……Page 111
9.4 Pressure switches……Page 112
9.6 Pressure gauges……Page 114
9.8 Back pressure regulation valves……Page 117
9.9 Suction- to- liquid heat exchangers……Page 118
9.10 Condenser pressure regulators……Page 119
9.11 Capacity reduction injection valves……Page 120
9.12 Relief valves……Page 121
9.13 Shut-off valves……Page 122
9.15 Strainer- driers……Page 123
9.18 Auxiliary components……Page 124
9.20 Suction separators……Page 125
9.22 Overheat protection……Page 126
9.23 Integrated control systems……Page 127
10.1 Balanced system design……Page 128
10.2 Evaporating temperature……Page 129
10.3 Evaporator……Page 130
10.4 Compressor……Page 131
10.5 Condenser……Page 132
10.6 Expansion valve……Page 134
10.7 Sizing pipe and other components……Page 136
10.8 Recheck components……Page 137
11.2 Pressure tests for safety……Page 138
11.4 Pipe- joining methods……Page 139
11.6 Pipe supports. Valve access……Page 140
11.7 Instruments……Page 141
11.9 Vibration……Page 142
11.11 Site pressure safety tests……Page 143
11.13 Charging with refrigerant……Page 145
11.14 Insulation……Page 147
11.16 Non- condensible gases……Page 148
11.17 Automatic gas purgers……Page 149
12.2 Liquid chillers……Page 151
12.3 Baudelot coolers and ice bank coils……Page 152
12.4 Ice manufacture……Page 153
12.6 Physical properties……Page 154
12.7 Brine circuits……Page 158
12.9 Thermal storage by frozen brines and ice……Page 159
13.2 Condensing units……Page 161
13.3 One- piece packages……Page 164
13.4 Split packages……Page 165
13.6 Application data……Page 166
13.8 Mobile application units……Page 167
13.9 Other packages……Page 168
14.1 Principles of cooling for preservation……Page 169
14.3 Pre- cooling……Page 170
14.5 Packing and handling……Page 171
14.6 Grouping of products……Page 174
14.8 Post- storage operations……Page 175
15.1 Size and shape……Page 177
15.2 Insulation……Page 181
15.3 Vapour barriers……Page 182
15.4 Sectional coldrooms……Page 184
15.5 Inbuilt construction……Page 185
15.6 Factory panel systems……Page 186
15.8 Frost- heave……Page 188
15.9 Door and safety exits……Page 189
15.10 Interior finish and fittings……Page 190
15.11 Evaporators……Page 192
15.13 Security of operation……Page 193
16.1 Meat industry applications……Page 195
16.2 Boned, boxed and processed meats……Page 196
16.3 Pork and bacon……Page 197
16.5 Fish……Page 198
17.1 Milk and milk products……Page 200
17.2 Ice- cream……Page 202
17.3 Ice lollies……Page 204
17.5 Wines and spirits……Page 205
17.6 Soft drinks……Page 206
18.2 Gas storage of apples and pears……Page 208
18.4 Frozen vegetables……Page 209
18.6 Cook/ chill……Page 210
18.8 Refrigeration of foods……Page 211
19.2 Air blast coolers and tunnels……Page 212
19.3 Contact freezing……Page 213
19.4 Freeze- drying……Page 214
20.1 The cold chain……Page 215
20.3 Order picking……Page 217
20.4 Refrigerated display……Page 218
20.5 Refrigeration for display……Page 220
21.2 Product cooling……Page 221
21.3 Conducted heat……Page 223
21.4 Convected heat……Page 224
21.5 Internal heat sources……Page 225
21.6 Heat of respiration……Page 226
21.7 Estimate analysis……Page 227
22.2 Chilled liquids for cooling……Page 230
22.5 Dewaxing of oils……Page 231
22.9 Low- temperature testing……Page 232
22.10 Chemical industry……Page 233
23.2 Calculation of properties……Page 234
23.3 Moisture content, percentage saturation, and relative humidity……Page 236
23.4 Dew point……Page 237
23.5 Wet bulb temperature……Page 238
23.6 The psychrometric chart……Page 239
23.7 Effects on human comfort……Page 241
23.8 Climatic conditions……Page 243
23.9 Other comfort factors……Page 245
23.10 Fresh air……Page 246
24.1 Winter heating……Page 247
24.2 Mixing of airstreams……Page 248
24.4 Water spray ( adiabatic saturation)……Page 250
24.5 Steam injection……Page 253
24.6 Air washer with chilled water……Page 254
24.7 Cooling and dehumidifying coil……Page 256
24.9 Multistep processes……Page 259
24.10 Cycle analysis……Page 261
25.1 Heating……Page 262
25.2 Addition of moisture……Page 263
25.4 Cooling and dehumidification……Page 264
25.5 Evaporative coolers……Page 265
26.2 Conduction heat gains……Page 270
26.3 Solar heat……Page 271
26.4 Fresh air……Page 274
26.5 Internal heat sources……Page 277
26.6 Assessment of total load estimates……Page 278
27.2 Velocity and total pressure……Page 280
27.3 Measuring devices……Page 281
27.4 Air- moving devices……Page 284
27.5 Noise and vibration……Page 289
27.6 Flow of air in ducts……Page 290
27.7 Flow of air under kinetic energy……Page 292
27.8 Flow of air in a room……Page 296
27.9 Grilles……Page 298
27.10 Return air……Page 299
27.11 Air filtration……Page 300
27.12 Cleanliness and cleaning of ducting……Page 303
28.1 Requirement……Page 304
28.2 Air- conditioning and comfort cooling……Page 306
28.3 Central station system. All air……Page 307
28.4 Zone, all- air systems……Page 312
28.5 Central station, combined air and chilled water……Page 313
28.6 Underfloor systems……Page 315
28.7 Packaged air- cooling units……Page 316
28.8 Multisplits……Page 319
28.10 Two- pipe splits……Page 320
28.11 Noise levels……Page 322
29.1 Psychrometrics……Page 323
29.2 Compressed air drying……Page 324
29.3 Applications……Page 325
29.4 High- temperature dehumidifiers……Page 326
30.1 The heat pump……Page 327
30.2 Heat recovery……Page 329
30.3 Apparatus and methods……Page 330
31.2 Detectors (sensors)……Page 331
31.3 Controllers……Page 334
31.5 Controls communications……Page 335
31.6 Control system planning……Page 337
31.7 Commissioning of control systems……Page 338
32.1 Specification……Page 340
32.2 Authority……Page 341
32.3 Setting to work……Page 342
32.5 Commissioning records……Page 343
33.1 Operation……Page 345
33.2 User maintenance……Page 346
33.3 Major maintenance work……Page 349
33.5 Fault- finding……Page 352
33.6 Spare parts……Page 353
33.7 Training……Page 354
33.8 The running log……Page 355
33.9 Exercises……Page 356
34.1 Assessment, identification, planning and targets……Page 358
34.3 Plant running conditions……Page 359
34.6 Excess condenser pressure……Page 360
34.9 Improved controls and equipment on existing plant……Page 361
34.10 Design of systems for energy economy……Page 362
34.11 Commitment to energy savings……Page 363
35.2 Compressors……Page 364
35.3 Condensing units……Page 366
35.4 Evaporators……Page 367
35.5 Reduction of air flow……Page 369
35.6 Room air- conditioners……Page 370
35.8 Analytical catalogue selection……Page 372
Appendix Units of measurement……Page 374
References……Page 376
Index……Page 380