Skip to main content

Condensed Heat - Optimization and scaling up of an energy efficient, long-during biomass condensation boiler with curved heat exchanger

Periodic Reporting for period 4 - C-HEAT (Condensed Heat - Optimization and scaling up of an energy efficient, long-during biomass condensation boiler with curved heat exchanger)

Reporting period: 2018-03-01 to 2018-11-30

The abrupt fall of the Brent Crude Oil price and, certainly, all its derivatives such as heating gas oil have caused a dramatic decrease of biomass boiler sales. The future of some of the best-known companies in this sector has been irreversibly altered and consequently some of the most important fossil fuel boiler manufacturers have finally dismissed the biomass division.
Other technologies for domestic heating (gas, oil-fired, electric or modern biomass boilers) are either unsuitable for moving towards a sustainable energy model, or insufficient in terms of energy efficiency. Whereas traditional boilers operate with fossil fuels, biomass boilers use a natural resource (pellets, wood chips, log). However, biomass heating appliances, although environmental friendly, perform inefficiently. Those few solid fuel condensing that have been developed have costly secondary heat recovery.
C-Heat have developed a cutting edge product based on sustainable feedstock (biomass pellets) being capable of working at low temperatures and built a biomass condensing boiler. C-Heat project consists of the development of the only biomass condensing boiler which needs no secondary heat recovers. Biocurve and Quintin have developed a biomass condensing boiler with a novel spiral heat exchanger and self-cleaning rotating burner which lead C-Heat to surpass from far the current state of art in terms of performance, (>10% than high-end average boilers), ripping design and price (at least 20% less than comparable solutions).
The objectives of C-Heat project are:
i. To redesign, improve and upscale of current portafolio (25kW and 100kW)
ii. To increase B&Q production capabilities
iii. To build a 25kW trasnportable demo to be used in fairs
iv. To install three C-Heat units in strategic locations


- The 25kW appliance test was carried out at CMC Laboratories in Thiene (Italy) under the supervision of TÜV Rheinland staff with success.
- 200 Kw boiler has been constructed and tested with positive results.
- 50 kW boiler, just developed, has proved to be a commercial success, assuming 30% of sales made in 2018.
- Complete design, parts procurement and the construction of 5 units 200 kW have been carried out
- 25kW boilers were completed with success at eh exhibition centers to sow customers boilers advantages in working conditions
- 100kW boilers were completed with success to demonstrate installers how to arrange boiler installation as maintenance
- Complete design, parts procurement and the construction of 1 unit 150 kW have been carried out.
The experimental work done so far, is related with the work package 1, specifically this work package aims to enhance the current portfolio, that is, boilers from 25kW to 100kW in order to succeed at two major challenger: i) reduce cost of products for market and ii) improve the emission parameters for entering in strict markets as well as several minor improvements. In order to carry out these objectives we have redesigned the 25kW boiler and carried out Computational Fluid Dynamics (CFD) simulations studies of 25 kW heat exchanger. To do that, all simulations have been carried out by reducing the outside diameter of the heat exchanger to 470mm, in order to reduce the width of the boiler. The other proposed changes with respect to the current model have been the modification of the number of tubes, the number of holes in the water distributors (water jets), the shape of the tubes (circular / oval) and the shape of the outer shell (cylindrical / narrowed).
The cases simulated correspond to the condensing mode of the 25 kW boiler model of Biocurve at full load (25 kW output power). The results obtained in the simulation fit accurately with the results obtained experimentally in the actual 25 kW boiler. The BioCurve boiler heat exchanger has a very innovative design, since instead of straight tubes (usual in standard manufacturers), fumes pass through the inside of curved tubes. This allows for a large exchange surface within a noticeably reduced volume.

As for the work Package 2, this work package aims to design and construct a 200kW in order to succeed major challenger. The work carried out during the second reporting period has allowed to carry out Computational Fluid Dynamics (CFD) simulations studies of 200 kW heat exchanger a series of simulations of the new heat exchanger were carried out using the tool developed during BioCurve's participation in the European Cloudflow Project. In addition during this period, it has been working in the realization of tests and adjustments of operation with a preliminary boiler prototype and burner allowing to reach 180 kW, as a previous step for the definitive construction of the boiler of 200 kW. With these actions we believe that the manufacturing and commissioning processes will be shorter, recovering the delay in the final boiler production process as a consequence of the delivery time of the tubes for the exchanger. The results obtained previously have allowed to keep running the boiler with different fuels, pellet and wood cheeps (wood chips and pellets for testing boiler and burner prototypes).
Concerning the work package 5, Portable demonstrative installation. The demonstrative portable installation has been built as an exhibitor with boiler and a complete heating system of 25 kW, allow us to show potential customers, installers, engineers, etc. the operation of the BioCurve boiler.
In addition, following our commissioning installers and customer demand, we have prepared boilers operation area with the following purpose:
1. Training of technical personnel for commissioning, operation and maintenance with boilers in real operation.
2. Demonstration of boilers operation according with customer specification.
3. Carry out real operation test to verify performance with different fuels and fuels delivered by the customer.

Technical conclusions:
- Redesign and improve the current portfolio (25kW to 100kW), Optimize the ash compactor, defined the communication protocol, Optimized the combustion process, Built a 25kW transportable demo to be used in fairs, certified the product in an external laboratory (TÜV Rheinland and Danish Technological Institute tests) for confirming the quality of C-Heat, design, set up and certify internally a 200 kW power output unit, encapsulated 1MW energy station by the integration of five 200kW units in a 40ft container.

Commercial conclusions:
Successfully prepared the path for a large implantation in Western Europe at best value for money costs: commercial and technical literature ready to be used, local approval for each country
Bioenergy is a very dynamic sector, which represents over two thirds of the total renewable energy consumption in the EU. Across Europe, 17M Ha are sustainably harvested for bioenergy generation and the EU is the world leader (13.5Mio Ton in 2014, 45% of the global share). C-HEAT consortium has identified relevant market segments linked to this trend. As an industry segment, the heating sector is expect to grow at 4% CAGR, passing from a final energy consumption of 92.6Mtoe in 2010 to 138.3Mtoe in 2020. Therefore, positive trends for upcoming years, such as the forecasted CAGR ratios for biomass boiler installation or incentives to renewable can be noticed.