www.kaeser.com Heat Recovery Systems PTG, SWT Series
Why recover heat? The question should in fact be: Why not recover heat? Amazingly, almost 100 percent of the electrical energy input to a compressor is turned into heat. Approximately 2 percent of this energy radiates away from the compressor package into the ambient surroundings and 2 percent remains in the compressed air. This means that with installation of heat recovery systems from KAESER KOMPRESSOREN, up 96 % of the energy dedicated to compressed air production can be recovered and reused. Heat recovery Significant s in spite of rising energy prices The trend for continuously rising fuel oil costs has had a knock-on effect on energy prices in general. However, you can counteract this tendency by equipping your compressor installations with high performance heat recovery systems. Therefore, in view of continuously soaring energy prices and concerns regarding the environment, the potential benefi ts and s are enormous. Gas heating 280 up to 54,000 For plate heat exchanger systems Compressor size Small Medium Large Benefit the environment and save costs with heat recovery Potential energy cost s through heat recovery Oil heating 284 up to 54,761 Heat recovery 96% recoverable heat energy Compressor model SM BSD 81 FSD 471 Rated power 9 kw kw kw Annual potential with fuel oil 842 5,5 29,476 3,826 25,5 3,969 See pages 6 and 7 for details regarding calculation of s potential. Heating with warm air Warmed compressor cooling air can be ducted away to provide highly effective space heating. With this method, up to 96 percent of the compressor s input energy can therefore be recovered as heat. Feed heat energy to a heating system Energy cost s through system optimisation Electrical power consumption Unbelievable as it may seem, in a fully encapsulated fl uid-/oil-cooled rotary screw compressor package, up to 76 % of the input energy for the compressor system can be recovered as heat. This drastically reduces the need for use of primary energy for heating purposes. Compressed air system investment Maintenance costs Energy costs Potential energy cost s If we examine the total costs (life cycle costs) of a compressed air system, we see that energy accounts for the lion s share. In fact energy costs still make up at least 70 percent of total costs even for optimised systems. However, a considerable proportion of these costs can be saved by using recyclable heat from the compressor via heat recovery. This not only benefi ts a company s annual operating budget to the tune of thousands of Euro per year, but also reduces the impact on the environment through a multi-ton reduction in emissions. Turn to pages 6 and 7 to see how much you could save. Heat recovery reduces costs and benefits the environment Up to 96 percent of the heat generated by a rotary screw compressor can be recovered as reusable energy. Every litre of fuel oil saved equates to a 2.727 reduction in emissions, which is not only benefi cial for the environment, but also results in signifi cant cost s. At today s energy prices, the amortisation period for a heat recovery system ranges between 6 months and 1 year (based on a plate heat exchanger feeding energy into a heating system). Warm air can also be recovered for use from older KAESER rotary screw compressors simply by installing additional ducting. We install optional fail-safe and plate heat exchangers for new rotary screw compressor systems (from kw and up). For older rotary screw compressor installations we offer specially designed retro-fi t kits.
Heat flow diagram Amazingly, almost 100 percent of the electrical energy input to a compressor is converted into heat. The adjacent heat fl ow diagram (right) shows how this energy is distributed throughout the compressor system and how it can be recovered: 96 percent of the energy can be recovered for reuse, two percent remains in the compressed air and two percent radiates away from the compressor package into the ambient surroundings. So where does the usable energy in compressed air come from? The answer is actually quite simple and perhaps surprising: During the compression process and conversion of the electrical drive energy into heat, the compressor charges the air it draws in with energy potential. This corresponds to approximately 25 percent of the compressor s electrical power consumption. This energy is only usable however once the compressed air expands at its point of use and in so doing absorbs heat energy from the ambient surroundings. Of course the amount of this energy that is available for use depends of the pressure and leakage losses within the compressed air system. Approx. 5 % heat dissipated by the drive motor Approx. 76 % of the reusable heat energy recoverable through fl uid cooling 100 % Total electrical power consumption Approx. 96 % heat energy available for reuse through heat recovery Approx. % of reusable heat energy recoverable through compressed air cooling 25 % ambient heat Approx. 2 % of the heat energy remains in the compressed air 25 % compressed air energy potential Approx. 2 % of the the heat energy from the compressor system radiates into the ambient surroundings Heat fl ow diagram Appropriate cooling The enclosed, compact design of modern rotary screw compressors makes them especially suitable for heat recovery. Direct use of the recyclable heat via a ducting system enables up to 96 % of the compressor s total energy requirement to be recovered and used for heating purposes. This is the case irrespective of whether fl uid-injection cooled compressors or dry-running screw compressors are used. Moreover, the feeding of recyclable compressor heat into hot water heating systems and industrial water systems is also well worthwhile: Over 70 percent of the installed compressor power can still be recovered for heating applications, and without the need for additional energy consumption. Unlike fl uid-cooled compressors however, dry-running rotary screw compressors must be primarily water-cooled in order to take advantage of this heat recovery method. Usable cooling air with a rotary screw compressor
Heat exchanger systems Hot water up to 70 C, or even C if required for various purposes can be produced either via a PTG plate heat exchanger or a SWT fail-safe heat exchanger. PTG heat exchanger systems are used for conventional water heating applications, whilst SWT fail-safe heat exchangers are recommended for applications that have no other interconnecting water circuits and where it is essential that the water being warmed remains completely uncontaminated. Heat fed to heating system PTG plate heat exchanger The cost-effective solution to enable utilisation of recyclable heat from rotary screw compressors. Application: Feeding of heat into central heating systems Laundries Electroplating General process heat SWT fail-safe heat exchanger Fail-safe plate heat exchangers prevent the possibility of water and cooling fl uids from mixing. Application: Food processing industry Water heating Chemical and pharmaceutical industry Cafeterias and large-scale catering establishments Warm air heat recovery When using recyclable heat for space heating, ducting simply feeds the warmed cooling air to where it is needed e.g. adjacent facilities, such as warehouses or workshops. At warmer times of the year when heating is not required, a louver fl ap can be used to vent this warm air to the outside. Thermostatically controlled, motorised louvers are able to precisely maintain the temperature in a room by enabling partial or full fl ow of heating air. Ducting installation Application: Auxiliary or main heating for warehouses or workshops To aid drying in painting and washing applications To create air curtains Improved effi ciency of oil burners through heating of combustion air Ducting for heating of adjacent rooms
Savings in detail: Warm air heat recovery All KAESER rotary screw compressors are designed for attachment of ducting, which is installed on-site. Neighbouring rooms and warehouse space, for example, can be heated with the warmed cooling air. PTG plate heat exchanger Rotary screw compressors from the SM series (from 5.5 kw) upwards can be equipped with PTG systems. Depending on the size of the compressor system, the PTG heat exchanger is either integrated within the unit or is installed externally. SWT fail-safe heat exchanger Rotary screw compressors from the ASD series upwards can also be equipped with SWT fail-safe heat exchanger systems. The SWT heat exchangers are always installed externally from the rotary screw compressor. Savings through hot air heat recovery For screw compressor SX 3 SX 4 SX 6 SX 8 SM 9 SM 12 SM SK SK 25 ASK 27 ASK 32 ASK 35 ASD 32 ASD 37 ASD 47 ASD 57 BSD 62 BSD 72 BSD 81 CSD 85 CSD 105 CSD 125 CSDX 140 CSDX 5 DSD 142 DSD 172 DSD 2 DSD 238 DSDX 243 DSDX 2 ESD 352 ESD 442 FSD 471 FSD 571 HSD 651 HSD 7 HSD 761 HSD 831 Rated motor power 2.2 3 4 5.5 5.5 7.5 9 25 37 55 0 0 0 3 360 400 0 500 Max. available heat energy 2.8 3.6 4.5 6.1 6.8 9.0.8.2.5 18.0.8 24.9.8 24.6 29.7 35.6 35.0 43.1 53.0 51 63 76 88 102 84 98 124 1 149 180 1 259 281 342 35 38 42 46 10 25 32 43 48 59 65 78 89 107 128 126 5 191 184 7 274 317 367 2 353 446 544 536 648 796 932 1012 1231 127 8 1 4 Usable hot air volume 1000 1000 1000 10 00 0 00 00 3500 4000 3800 3800 00 5400 8000 9400 9400 10700 000 100 00 14000 14000 000 000 34000 34000 40000 10000 Cooling-air heating Model kw kw MJ/h (approx.) 8 14 14 10 17 17 18 19 19 19 24 24 28 27 26 23 26 14 Heat is not only needed in winter It goes without saying that heating is necessary during the winter months, but it is also required for signifi cant periods at other times of the year, such as in spring and autumn. This means that heating energy is actually required for approximately 00 hours per year. Required heating energy(%) 100 % Fuel oil l 473 608 761 1031 49 1994 31 2789 42 3685 48 4687 5544 6693 8023 7887 97 944 493 14197 17127 19831 986 189 085 27944 34029 33578 40564 49803 58367 63325 77071 7932 8609 9465 10276 Jan Feb 12 58 2812 33 4148 5438 6084 7606 8296 10049 4 12781 8 18252 879 8 26487 32571 341 387 46705 54079 62683 5 606 763 92797 967 0618 58 97 172687 0173 Required heating energy over the course of a year Mar Einsparpotenzial bei 00 h Apr Fuel oil potential 231 23477 258 28023 May Jun Saving potential for 00 hrs 331 426 553 7 804 1065 96 62 1952 29 2580 2946 3281 3881 4685 56 55 6799 8361 80 9938 989 882 0 51 460 19561 238 23505 28395 34862 40857 44328 53950 5552 6026 6626 7193 Jul Natural gas m³ 392 504 6 854 952 1261 53 1849 23 25 53 3487 3884 94 5546 6648 6536 8049 9897 9524 765 14192 433 148 686 181 236 28198 27824 336 41270 48356 52474 63866 6573 74 7843 85 Aug Sep Oct Nov Natural gas 784 1008 1260 1708 14 25 36 3698 46 5042 6106 6974 7768 9188 092 96 172 098 19794 148 235 28384 32868 38096 372 36602 46312 56396 55648 676 82540 96732 104948 127732 146 14268 686 170 Einsparpotenzial bei 00 h Saving potential for 00 hrs Dec 294 378 473 641 714 946 1240 87 1733 1891 26 29 3446 40 4986 42 6037 7423 7143 8824 10644 12325 14286 765 726 17367 249 868 250 953 362 39356 470 49 5351 5882 6386 Savings through PTG plate heat exchanger system For screw compressor SM 9 SM 12 SM SK SK 25 ASK 27 ASK 32 ASK 35 For screw compressor 5.5 7.5 9 Rated motor power 4.6 6.2 8.3 9.4 12.0.0.8 17.9 Max. available heat energy Model kw kw MJ/h ASD 32 ASD 37 ASD 47 ASD 57 BSD 62 BSD 72 BSD 81 CSD 85 CSD 105 CSD 125 CSDX 140 CSDX 25 DSD 142 DSD 172 DSD 2 DSD 238 DSDX 243 DSDX 2 ESD 352 ESD 442 FSD 471 FSD 571 HSD 651 HSD 651 SFC HSD 7 HSD 761 HSD 761 SFC HSD 831 HSD 831 SFC Rated motor power 25 37 55 0 0 0 3 360 382 400 0 410 500 5 Max. available heat energy Model kw kw MJ/h.8 18.6.6 27.1 26.6 33.0 40.7 39.0 48.4 59.0 69 79 66 76 97 9 7 143 172 3 8 266 3 4 339 372 353 405 398 57 67 81 98 96 9 147 140 174 2 248 284 238 274 349 428 4 5 619 731 785 958 27 1094 10 39 1271 18 1433 17 34 43 47 57 64 (ΔT 25 C) 0. 0. 0.29 0.32 0.41 0. 0.54 0.62 Volume of hot water heating to 70 C (ΔT 25 C) 0.54 0.64 0.78 0.93 0.92 1.14 1.40 1.34 1.67 2.03 2.40 2.70 2. 2.60 3. 4.10 4.00 4. 5. 7.00 7.50 9. 10.80 10.50.70 12.80 12. 14.00.70 Volume of hot water heating to 70 C (ΔT 55 C) 0.25 0.29 0.35 0.42 0.42 0.52 0.64 0.61 0.76 0.92 1.08 1.24 1.03 1.19 1.52 1.86 1.83 2.24 2.69 3.18 3.41 4.17 4. 4.76 5.31 5.83 5.53 6.34 6.23 (ΔT 55 C) 0.07 0.10 0. 0. 0.19 0. 0.25 0.28 Installation of the PTG system Installation of the PTG system Installation of the SWT system Fuel oil l 777 1048 1403 89 28 97 2670 25 Fuel oil l 3561 4192 5093 6107 5994 7437 9172 8789 107 96 549 17803 14873 17127 859 26817 26366 326 38761 747 49127 59944 70536 68508 76395 83832 79550 91269 89691 Fuel oil potential 29 2858 3826 4333 55 5991 7281 8249 Savings through PTG and SWT heat exchanger systems Calculation example for ASD 32 For fuel oil Maximum available heat capacity:.8 kw Fuel value per litre of heating oil: 9.861 kwh/l Fuel oil heating effi ciency: 0.9 Price per litre of fuel oil: 0.60 /l 1 kw = 1 MJ/h x 3.6.8 kw x 00 h Cost : x 0.60 /l = 2,7 0.9 x 9.861 kwh/l For natural gas Saving potential for 00 hrs Fuel oil potential 97 432 889 654 346 281 12 23968 29743 36258 42402 48549 40559 46705 59609 731 710 87880 105701 1242 3969 3467 192352 1868 8329 8610 2933 248891 2487 544 734 982 1.2 1.4 1.538 1.869 2.8 Saving potential for 00 hrs 2493 2934 3565 42 4196 56 64 62 7635 97 10884 12462 104 989 1 18772 186 558 273 323 34389 41961 493 47956 53477 58682 55685 63888 62784 Natural gas m³ 644 868 62 17 81 18 7 Natural gas m³ 2951 3473 40 5061 4967 62 7600 7283 38 018 12885 143 12325 14192 184 2 849 26704 3 378 40710 49673 580 56769 635 69468 659 6 74323 Natural gas 1288 1736 2324 2634 3362 3642 4426 5014 Saving potential for 00 hrs Natural gas 52 6946 8440 101 9934 12324 0 6 18976 036 25770 29506 24650 28384 368 44444 43698 53408 64240 8 814 99346 60 3538 126610 8936 1840 1260 148646 Maximum available heat capacity:.8 kw Fuel value per m³ natural gas: 10 kwh/m³ Natural gas heating effi ciency: 1.05 Price per m³ of natural gas: 0.70 /m³ 1 kw = 1 MJ/h x 3.6 Cost :.8 kw x 00 h 1.05 x 10 kwh/m³ x 0.70 /m³ = 2,107 483 651 872 988 1.261 1.366 1.660 1.880 Saving potential for 00 hrs 2605 35 3796 3725 46 5700 5462 6779 8264 9664 10065 9244 10644 586 667 387 028 240 28431 533 37255 43838 42577 47479 501 49440 56723 55742 7
www.kaeser.com KAESER The world is our home As one of the world s largest manufacturers of rotary screw compressors, KAESER KOMPRESSOREN is represented throughout the world by a comprehensive network of branches, subsidiary companies and authorised partners in over 100 countries. With innovative products and services, KAESER KOMPRESSOREN s experienced consultants and engineers help customers to enhance their competitive edge by working in close partnership to develop progressive system concepts that continuously push the boundaries of performance and compressed air effi ciency. Moreover, the decades of knowledge and expertise from this industry-leading system provider are made available to each and every customer via the Kaeser group s global computer network. These advantages, coupled with KAESER s worldwide service organisation, ensure that all products operate at the peak of their performance at all times and provide maximum availability. KAESER COMPRESSORS Australia Pty. Ltd. Locked Bag 1406 Dandenong South Vic. 34 Zenith Road Dandenong Vic. 31 Phone: +61 3 9791 5999 Fax: +61 3 9791 5733 E-mail: info.australia@kaeser.com www.kaeser.com P-6AUS.1/12 Specifi cations are subject to change without notice