Heat Recovery Systems For GenSets: Is It Just A Lot of Hot Air?

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1 Heat Recovery Systems For GenSets: Is It Just A Lot of Hot Air? 17 th November 2015 Dr. Hezlin Ashraf-Ball Engineering Manager EJ Bowman (Birmingham) Ltd

2 Introduction EJ Bowman (Birmingham) Ltd Established in 1919 (almost 100 years) Experts in design and manufacture of heat exchangers Marine engines, land based engines, automotive test facilities, CHP, firepumps, swimming pool and many more Shell & tube and plate type heat exchangers UK manufacturing facility ISO 9001:2008 certified More than 1 million heat exchangers sold Export over 70% of all products Stockists worldwide Hezlin Ashraf-Ball Engineering Manager Joined Bowman in August 2015 Understanding of thermodynamics within heat exchanger systems for Power Generation, Renewable Energy, Automotive Testing and Aerospace Components Icing Test Previous experience: Chief Project Engineer Heat Exchanger Design Leader Research Engineer Awarded PhD in Chemical Engineering from Birmingham University in 2005

3 Overview 1. Principles of Combined Heat and Power (CHP) 2. Benefits of offering a CHP Solution 3. Heat recovery potential from a Genset 4. Turning a Genset into a CHP total solution 5. Heat exchanger installations-genset CHP 6. Total solution heat exchangers 7. Background of shell and tube heat exchangers 8. Critical characteristics for heat exchanger selection 9. Design and development work 10. Products installed for CHP applications

4 Principles of CHP Definition: Simultaneous generation of usable heat and power (usually electricity) in a single process. Examples of applications: Industrial CHP Small Scale CHP-Genset Micro CHP CHP with district heating Fuel 100% Combined Heat and Power Generation Losses 20% Power 31% Heat 49% 80% Usefule nergy * Association of Decentralised Energy 33 to 50 % of the fuel input available as useful heat * Digest of United Kingdom Energy Statistics (DUKES) 2015

5 CHP The benefits Benefits from reciprocating engine perspective*: 33 to 50 % of the fuel input available as useful heat Useful heat at no additional cost in terms of fuel or CO 2 generated Adding waste heat recovery will increase the overall efficiency from around 31% to 80%* The waste heat can be used as either to provide heating or hot water to heat up process streams such as hot water, thermal oil, steam generator to generate additional electricity or provide a cooling facility * Digest of United Kingdom Energy Statistics (DUKES) 2015

6 CHP The benefits Possible financial incentives/ support measures for Good Quality CHP in the UK *: Climate Change Levy (CCL) Carbon Price Support (CPS) Enhanced Capital Allowances (ECA) for plant and machinery Business Rates for CHP power generation plant and machinery Reduction of VAT (from 20 to 5 per cent) on domestic micro-chp installations Renewable Obligation Certificates (ROCs) Specific Renewable Heat Incentive (RHI) for biomass fuelled Contract for Difference (CFD) Carbon Reduction Commitment Energy Efficiency Scheme (CRC) * Digest of United Kingdom Energy Statistics (DUKES) 2015

7 Heat Recovery Potential From Genset Exhaust 4 Useful Heat 55% Air intake Turbocharger 1 Useful Heat 12% Exhaust Reciprocating engine Engine Jacket Water Generator lubrication oil 3 2 Useful Heat 24% Useful Heat 9%

8 Turning a Genset into a CHP Total Solution Useful Heat (50 to 70 C) Heat Exchanger Air intake 1 Turbocharger Exhaust Reciprocating engine Exhaust 4 Generator lubrication oil Heat Exchanger Useful Heat (Up to 110 C) Vent/Stack Individual and/or combination of useful heat can be used for: Heating (commercial or domestic buildings) Process heat from hot water or thermal oil Steam generation Organic Rankine Cycle (power augmentation option) Absorption Chiller Engine Jacket Water 3 Heat Exchanger Heat Exchanger 2 Useful Heat (60-70 C) Useful Heat (70-95 C)

9 Heat Exchangers Installations-Genset CHP Exhaust 4 Vent/Stack Charge Air Cooler 12% Air intake 1 Turbocharger Exhaust Reciprocating engine Generator lubrication oil Exhaust gas heat exchanger recovers 55% useful heat Bowman heat exchangers are compact allowing: Ease of integration within the engine system Minimal cost for reengineering and/or redevelopment Engine Jacket Water 3 2 Header Tank recovers 24% useful heat Oil Cooler recovers 9% useful heat

10 Total Solution - Heat Exchangers Exhaust gas heat exchanger A high efficiency solution for waste heat recovery from the exhaust stream, suitable for Biogas, Diesel and Natural Gas applications up to 1MW Header tank heat exchanger Unique design combines high efficiency engine cooling, with long life durability, suitable for engines up to 1400kW Charge air cooler Improves fuel efficiency and enhances engine performance by cooling turbocharged air, suitable for engines up to 800kW Oil cooler Recovers valuable heat energy from the engines lubrication system, suitable for applications up to 1900kW Tubestack Materials Selection Stainless steel Cupronickel Titanium Body Aluminium casting (BS EN 1706) Stainless steel End Covers Cast iron, C coat 300 Composite Naval brass

11 Background of Shell and Tube Design Q = U x A x dt Q = Heating/Cooling Duty (kw) U= Overall heat transfer coefficients A = surface area (m 2 ) dt = temperature difference between the two fluids Design criteria: One fluid flows on the inside of the tubes, whilst the other is forced through the shell Baffles are introduced to force the flow across the tubes to induce higher heat transfer Segmental baffles Disk and donuts Head arrangements allow single or multiple tube pass flow Trade off between pressure drop and heat transfer is important in the design selection process

12 Critical Characteristics For Heat Exchanger Selections Exhaust Inlet Fuel type Mass Flow & Temperature Exhaust Exit Acid dewpoint limit Water Inlet Not to exceed 110 C Water Inlet Mass Flow Temperature Depending on the types of flue gas used in the Genset (sulphur content) different exhaust gas exit temperature will be recommended This is to ensure that the heat exchangers are not exposed to the risk of acid dewpoint and fouling All products are categorised under Standard Engineering Practise under Pressure Equipment Directives (PED 97/23/ EC)

13 Work with customers to incorporate requirements into our design and development process, wherever possible On-going product improvement programme for heat transfer, pressure drop etc. Constantly seeking new market applications In house bespoke computer selection programs In-house testing facilities FEA and CFD capabilities Design and Development

14 Bowman CHP solutions around the world The British Antarctic Survey Halley VI Research Station SSI, Fort Providence a remote Northern Canadian community Turnberry Golf & Luxury Resort in Scotland Grain drying project in Finland Eco-residential project in Finland Other waste heat recovery options Stirling Engine (additional electricity) Organic Rankine Cycle (additional electricity) Absorption Chiller (cooling)

15 The British Antarctic Survey Halley VI Research Station The station located on the Brunt Ice Shelf Antarctica Fully operational since 2013 Winter temperatures plummet to -50 C and snow falls for half of the year Exhaust gas heat exchangers provide heat to support the BAS team who live and work at the base all year round.

16 SSI, Fort Providence, Northern Canada Winter temperatures can fall to -40ºC Utility and diesel costs significantly higher, due to remote location The community has 800 people, situated on the McKenzie River in the Northwest Territories of Canada Installed 150kW Genset based CHP units using Bowman exhaust gas heat exchangers plus charge air coolers 60% increase in heat capture from the Bowman units 52% saving on cost of energy using diesel generators with CHP

17 Grain Drying in Finland Exhaust gas units on a heat recovery (heat pump) solution for grain drying Will reduce diesel fuel consumption during the grain drying season on this particular farm by around 18,000 litres This is the first system to be installed in Finland Eco-Residential Project in Finland Eco residential project Wood-gas fuelled CHP plant 5 Exhaust gas units fitted to Sisu Gensets Application recovers waste heat energy and cools gas produced by wood burner Provides heat and power to ten homes

18 Turnberry Golf Resort in Scotland Application driven by expanding energy demand Desire to reduce energy costs and CO2 emissions Bowman exhaust gas units installed on to generators High efficiency independent CHP solution for heating requirements

19 Using waste heat to deliver more power Stirling Engine Cool Energy utilised waste heat from a 30kW Genset to produce additional electricity The heat is used within their 3kW SolarHeart Engine using Stirling Engine Concept Organic Rankine Cycle (ORC) turbine generator systems Exhaust gas heat exchanger can supply hot water (thermal oil) for the evaporation (superheating) of fluid before turbine Absorption chiller Exhaust gas heat exchanger can supply hot water to supply heat for refrigerant s evaporation

20 Summary Up to 49% of waste heat can be recovered and turned into useful heat for: Heating for commercial or domestic buildings Process heat from hot water, thermal oil or steam Additional electricity Stirling Engines and Organic Rankine Cycle Refrigeration option absorption chiller Financial incentives offer viable route for turning a Genset into a CHP solution Integration of compact heat exchangers into the existing footprints eliminates the need of re-design/re-development Selections process focused on heat duty requirement and pressure drop limitations taking into account Genset fuel type to minimise acid dewpoint fouling It s worthwhile looking at recovering heat from all waste source within Genset Exhaust gas (55%) Jacket water (24%) Charge air (12%) Engine oil (9%) Bowman have vast experience in providing total solution for Genset waste heat recovery with clients all over the world

21 Questions & Answers