Oswald | Heat Exchanger Design Services

Heat Pipe systems

Our association with AMS Energy, Columbia, Tennessee

Our expertise at designing energy systems and our relationship with AMSEnergy (experts in the design and manufacture of heat pipe heat exchangers), we can design and supply you with a heat pipe system featuring thermosyphon heat pipe technology for your industrial process.

Oswald Consultancy specialises in designing unique, bespoke heat exchangers for demanding applications and combining that with AMSEnergy’s heat pipe expertise we can find the optimum solution for your industrial heat recovery or heat transfer process.

Heat pipes have no moving parts, provide a more compact, lower pressure drop route to heat exchange which delivers higher efficiency heat transfer than more orthodox heat exchangers.

To find out more visit http://www.amsenergy.com/heat-pipe-heat-exchangers/

We specialise in the design and development of bespoke, specialist heat exchanger systems. Our strength is understanding the whole system requirements, and, being independent of heat exchanger manufacturers, we give impartial advice. We will insist on understanding system flows, heat and control. We can:

• Design and manufacture you a special heat exchanger with control system
• Help you design your own heat exchangers
• Help you select from a catalogue: you choose.

We usually create thermal models from first principals; strengthened by our 30+ years experience in both conventional and innovative heat exchanger designs whilst building on our understanding of system behaviour. System understanding includes: interaction of heat transfer, thermodynamics, aerodynamics, fluid flow, gas power cycles and mechanical design.

Download our Application design of heat exchanger systems v2.pdf,
See some Heat Exchanger Case Studies of our recent work

Heat Exchanger Design, Development and Testing

Past experience & CV

Whilst at Rolls-Royce Jim spent many years designing, developing heat exchangers/ recuperators for the gas turbine industry. Our consultancy brings that experience to other industries:

Areas of heat transfer expertise: 2004 - 2013 Oswald Consultancy Ltd

(See detailed case studies)

•Heat recovery systems
•Lead development and testing of advanced, bespoke heat exchangers
•Thermal model design of domestic condensing boiler
•Heat exchangers for contaminated flows to prevent fouling
•Plate fin heat exchanger design
•Heat transfer surface design
•Development of heat transfer testing programmes
•Phase change thermal stores (molten salt and ice storage)
•Air to air heat exchangers (or other gases)
•Water to water heat exchangers (or other liquids)
•Air to water heat exchangers
•Brazed plate fin heat exchanger for micro turbine, stainless steel
•Spiral recuperator, stainless steel
•Welded plate fin heat exchanger
•Steam turbine plant design
•Advanced heat exchanger designs - plate fin, shell tube
•Power generation design - steam plant, microturbines,
•High quality thermal analysis of buildings - coheating tests, building energy signatures

1989 – 2001. J.Oswald, designed, developed, tested gas turbine heat exchangers (recuperators) whilst employee of Rolls-Royce:

•Brazed plate fin heat exchanger, micro turbine, stainless steel plate fin

•Novel spiral recuperator, stainless, welded plate fin

•Design, develop, manufacture test, validation, spiral recuperator variants Stainless, INCO. Multi-million £ development programme.

Jim Oswald inspecting the nameplate of a Kettle Boiler in the USA which is installed to raise steam using heat from hot gas turbine air before the air is passed back to the turbine for blade cooling.

Its about the whole system

Sizing the heat exchanger is easy, what matter is getting the whole fluid system to work. That involves balancing and control flows and temperatures.

Whole-system thinking is central to our approach; understanding energy systems by how the various elements of that system interact. We start from first principles and build our own heat exchanger thermal and pressure drop models. A recent review of expensive proprietary software confirms we already do it all, but from the bottom up.

Our custom designed thermal models are based on 30+ years experience of both conventional and innovative heat exchanger designs. We also lever our knowledge of gas power cycles, thermodynamics, fluid flow and mechanical design.

By building unique heat exchanger models (often in Excel) we get, and help our customers to get, an understanding of the fundamental sensitivities in their designs and thereby reduce risk in delivering their finished product and system. Customers wanting design only support, get to keep these customised thermal models (often built as an Excel spreadsheet) and use them over and over, and thereby saving further external costs.

We are also very happy to manufacture a special heat exchanger for your needs whether that is a bespoke production heat exchanger or a special heat exchanger for test rig purposes.

Heat Exchanger Capabilities:

•Feasibility - We can assess your heat transfer requirements and provide experienced insights into the key technical, operational and financial considerations relevant to your system.

•Detailed Designs - We can carry out detailed design of unique heat exchangers.

•Manufacture - We do not have our own manufacturing facilities but have any specialist equipment such as heat exchangers manufactured in the West Midlands supply chain. This enable us to design the most appropriate material and method to your need.

•Controls - We sometimes design and build controls for heat systems

•Testing - We can carry out full testing of manufactured or installed parts, either in-situ or in the lab. This enables us to validate the performance and characteristics of the heat exchanger prior to delivery.

process diagram and heat exchanger design

Molten salt thermal storage system designed for Culham Centre for Fusion Energy (JET)

Thermal design of heat exchanger sections

Inspection of a prototype heat exchanger plate

Testimonials

“We were very pleased with heat exchanger sizing tool Oswald Consultancy built and supplied to us. This is an easy to use Excel tool that allows us to input our flow parameters and size our own tube-in-tube heat exchangers. We are now building and testing these for our customers in the anaerobic digestion market. We are engineers who are confident designing and building specialist mechanical process plant, but felt we would benefit from specialist heat exchangers expertise. We recommend them to you if you have a specialist heat exchanger design problem that needs support.”

D.Shepherd C.Eng MIMechE from Atlas Engineering in Slough (18th Nov 2013)

We designed and manufactured this for Eaton Ltd, to allow them to test aircraft fuel systems down to -50°C as part of ARP1401. It delivers 25kW of cooling by controlling the flow of liquid nitrogen to two copper coil heat exchangers seen on the left of the photograph.

A large central tank holds 100 litres of Duratherm (a non-flammable heat transfer fluid) which is pumped through the copper coil heat exchangers. Once this reaches the target temperature, as set by the control settings, a second pump starts and passes the Duratherm from the tank to the client’s test tank.

Oswalds designed the copper cooling coils for high efficiency and include both a boiler section and super-heater section to extract the maximum possible cooling from the liquid nitrogen. During testing the Nitrogen exhaust temperature was measured at warmer than -90°C, having boiled from -200°C. The system is CE marked and ATEX rated due to the possibly explosive test environment. It is also suitable for carrying out Air790c testing.

2015: Liquid Nitrogen Cryogenic Cooling System

Tests results demonstrate both cooling rate and stable control

We designed and then subcontracted the manufacture of this tube cooler as the other part of the liquid nitrogen system delivered to Eaton Ltd (see above).

This heat exchanger receives the cold Duratherm from our Liquid Nitrogen cooling skid (above) and sits in the test facility aircraft fuel tank. The overall aim of the testing is to test aircraft pipework and systems in the test tank down to -50°C as part of the requirement for ARP 1401. This ARP test requires a very small difference in temperature between heat exchanger and aircraft fuel of only 12°C. We subcontracted the manufacture to Serck and were very impressed with the manufacturing quality.

Application: Jet Fuel cooling test (ARP1401 / Air790c) & Duratherm XLT-120 (+20°C to -70°C)

Fluid: Liquid Nitrogen (-200°C to -90°C)

Industry : Aerospace

Client: Eaton Ltd

Pressure: Duratherm (<0.5 bar) and Boiler (Atm.)

Year: 2015

Power: 30 kW cooling

Task: Design & Manufacture in Nuneaton, UK.

Materials: Copper Coils, Steel Tank

Application: Jet Fuel Cooling test (ARP1401 / Air790c)

System Fluids : Duratherm XLT-120 (+20°C to -70°C) &

Jet A1 fuel (20°C to -50°C)

Industry: Aerospace

Client: Eaton Ltd.

Pressure: <0.5bar

Year : 2015

Power: 25 kW

Task: Design & Manufacture

Material : Stainless Steel (316)

2012 Molten salt to steam heat exchanger design (Nuclear Fusion heat store)

2013 Plate Heat exchanger

2014: Plastic Heat Exchanger for process fluids

2014: Shell & Finned Tube demonstration heat exchanger

2014: Cooling Syngas Produced from Waste Gasification and Pyrolysis

2015: Aircraft Fuel cooling Heat Exchanger

We have designed heat exchangers for waste to energy applications including condenser for plastic waste gasification and tyre pyrolysis gas cooler. The condenser was designed to ensure that the condensing surface can be cleaned by a scraping mechanism, as fouling is a major concern for this application. The gas cooler has a special insulated tube tips for very high pyrolysis gas temperature at inlet.

Application: Syngas Condensing/Cooling

System Fluids: Syngas (Methane/Dodecane)

Water

Industry: Waste to Energy (Gasification and Pyrolysis)

Client: Premier Green Energy

Pressure: Water (2 bar) and Syngas (2mbar)

Year: 2014

Power: 33 kW

Task: Heat Exchanger Thermal Design

Material: SS 304

Oswalds designed and manufactured this heat exchanger as part of a test skid for Swansea University to teach students the differences between counterflow and co-flow heat exchanger performance.

Application: Demonstration heat exchanger – co-flow vs. counterflow

System Fluids: Air to Water (80°C to ambient)

Industry : Education

Pressure : Water (2 bar), Air (3mbar)

Client : Swansea University

Power : 1.1 kW

Year : 2014

Material : Copper finned tube, stainless steel

Task : Design & Manufacture

Application: Process heating

System Fluids: Liquid to liquid

Industry: Coating / Finishing

Pressure: <0.5bar

Client: Confidential

Power: 800 W

Year: 2014

Material: Plastic HX tubes

Task: Concept design & prototype manufacture

Oswalds designed and manufactured this heat exchanger as part of a test skid for Swansea University to teach students the differences between counterflow and co-flow heat exchanger performance.

Novel plate heat exchanger 200C, dusty atmosphere - likely to block, first sample inspection by Hezlin.

We also designed the whole system including blower and ducting. The customer was delighted with this world first.

Test results showed we achieved performance expected.

Application

Asphalt Production for Road

System Fluids

200C dusty air to ambient air

Industry

Construction

Pressure

0.1 bar (Cooling air) and Dusty air (3 mbar)

Client

Mixlance

Power

450kW

Year

2013

Material

Steel

Task

Design, manufacture & test

1998, Rolls-Royce Spiral Recuperator (675C)

2008 Kettle boiler design & testing

Application

Nuclear Fusion Heat Store

System Fluids

Molten Salt

Industry

Nuclear Fusion / Steam

Client

Culham Centre for Fusion Energy (JET)

Pressure

86bar (Steam)/ 30 bar (Salt)

Year

2012

Power

1GW

Task

Concept design of heat exchanger

Material

Steel

Culham Centre for Fusion Energy asked Oswalds to design and size a liquid salt to steam heat exchanger. This is part of their long term fusion reactor R&D whereby they want to store fusion power in liquid salt.

We found a temperature crossover issue on the heat exchangers and identified an alternative salt which resolved the problem.

2000, Rolls-Royce Spiral Recuperator (650C)

2006, Heat exchanger Performance Model

Application

Gas Turbine shell-and-tube heat exchanger

System Fluids

Air & Water/Steam

Industry

Power generation

Client

Teeside Power Station

Pressure

Air (15 bar) and Water (1 bar)

Year

2008

Power

1.5MW

Task

Design & test

Material

Steel

Oswalds worked on this power generation heat system for about 3 years. Starting with the original design sizing and layout, to testing and validation of energy saving at the end. We defined the instrumentation for the combustion equipment and measurements showed that our transient model agreed well with the measured results (see graphs).

Application

Double pipe heat exchanger

System Fluids

Water

Industry

Biowaste/Digestate

Client

Bio-energy

Pressure

2 bar

Year

2006