ABSTRACT OBJECTIVES AND STRATEGIC ASPECTS 2.1 CONTRIBUTION TO A SUSTAINABLE ENVIRONMENT 2.2 AIMS AND OBJECTIVES 2.3 COST EFFECTIVENESS OF THE RESEARCH 2.4 PROGRESS AGAINST SCHEDULE 2.5 COMPARISON OF ACHIEVED OBJECTIVES AGAINST PLANS TECHNICAL ASSESSMENT 3.1 WP1 SCOPING STUDY AND TEST BED DEVELOPMENT 3.2 WP2 DEVELOPMENT OF CONTROL TECHNOLOGY 3.3 WP3 TESTING CONTROL TECHNOLOGY 3.4 WP4 EVALUATION OF PERFORMANCE AND MARKET ACCEPTABILITY EXPLOITATION PLAN 4.1 POTENTIAL APPLICATIONS 4.2 MARKET POTENTIAL 4.3 VALUE ANALYSIS 4.4 PROTECTION OF RESULTS 4.5 EXPLOITATION STRATEGY MANAGEMENT AND CO-ORDINATION ASPECTS PROJECT PROGRAMME REVIEW REFERENCES FURTHER INFORMATION CONTROLLER EFFICIENCY IMPROVEMENTS FOR COMMERCIAL AND INDUSTRIAL GAS AND OIL FIRED BOILERS

Final Publishable Report Abstract

This is the publishable report for the above project. The project officially started in December 1998, but actually commenced with a kick-off meeting in February 1999. The project finished in April 2001. The main objectives of the project were to assess the energy saving potential of an existing prototype boiler controller, (known within the project as the BRITTECH Controller), and to improve its efficiency and applicability. A research feasibility study carried out prior to this project had shown that the existing controller had potential to save energy.

However, this had not been backed up with firm scientific evidence. Furthermore, the commissioning of the controller had proven to be a difficult, and time consuming process that could only be carried out by those involved in its development. The project aimed to: · identify the most appropriate application areas, i.e. where savings from the use of this technology are expected to be significant, · improve the controller algorithm in order to enhance its energy saving potential and its applicability and, in particular, to: · develop a self-commissioning algorithm which makes its application easier and practicable and therefore allows the widespread and cost effective installation of the controller. The project has been successfully completed with all tasks achieved. Some of the main results of the work are summarised as follows:

1. The BRITTECH controller, when commissioned properly, is capable of saving energy in a number of applications. Simulation studies predict that savings of between 5% to 25% are possible in a significant number of existing installations depending on zonal control: in manually controlled radiators up to 25%, in tightly controlled zones (e.g. TRV) 5% to 10%, and in many existing buildings, which fall between these two extremes, savings within this range are possible. Some of these findings have also been corroborated by preliminary test results in both an emulator test rig and a real test building. A new boiler controller OWT has been successfully developed and tested in simulation, a specially built and monitored "ICITE" building in Italy, and UK and German field trials. The new controller is self-commissioning and addresses many of the inefficiencies evident with the programming and optimisation of boiler controllers. The performance of the OWT is consistent throughout the simulation study, the ICITE test and the field trials. 5-10% of energy saving can be obtained in systems with controlled terminals. Up to 30% of energy savings can be obtained in systems with uncontrolled terminals. A proposal has been made to the SME partners and industrialisation of OWT is now near completion in the UK with the "Fuelstretcher" controller.

2. A rigorously validated simulation model of heating systems with commercial gas or oil burning boilers has been developed. Two simulators have been configured based on the model to represent the thermal dynamics of typical systems. These two simulators are used throughout the project, for analysing the existing Brittech control strategy, developing and testing the new improved control strategies, and developing the emulator (the test-rig).

3. A small-scale physical emulator, the boiler test-rig has been developed. It has been used to produce the experimental data for the validation of the boiler model and the boiler controller model that are integrated in the overall simulation system mentioned above. It was also used to test the performance of the hardware prototype controllers before they were sent off for the ICITE testing and the field trials.

4. The existing algorithm has been studied and areas where it can be improved leading to a more advanced controller have been identified.

5. A self-commissioning controller algorithm - OWT (Optimal Water Temperature) - has been developed and tested in simulation. The simulation study indicated that this algorithm is capable of improving both the long-term energy efficiency and the thermal comfort of heating systems.

6. An important part of the programme was to develop a robust short-term comparison of energy consumption on the basis of Degree Days. This was used to assess field trial performance and results compared favourably with simulation.

7. A hardware prototype controller has been developed with the two algorithms implemented. It is based on a microprocessor from Microchip (PIC16C77). It has been tested with the simulators to ensure that the algorithms proven in the simulation study have been correctly implemented in the microprocessor. To carry out such a test, a serial communication interface between the hardware prototype controller and the simulation system (Simulink) has been developed. This interface is important as it allows systematic testing of the prototype in a pure simulation environment before the emulator testing. Furthermore, the clock of both the simulator (Simulink) and the hardware prototype controller can be synchronised and scaled such that faster-than-real-time testing can be performed.

8. The hardware prototype controller has been tested in the test-rig. The result indicated that it was suitable for the industrial installations in the ICITE test building and the real buildings selected for the series of field trials.The control performance of the hardware controller has also been examined in the test-rig. The results were consistent with the simulation study.

9. The hardware prototype controller has been tested in the ICITE test building. The OWT algorithm have been tested and compared with a traditional external temperature compensated boiler (BMS) controller that is supplied by one of the industrial partners and which is regarded as representing current best practice in this project. Overall the result is very consistent with the simulation study and testing in the test-rig and showed savings of about 6%. 10. Four prototype controllers have been sent to the industrial partners for a series of field trials. Four buildings were originally selected for the field trial, including one hospital and one office building in the UK, one office building in Germany, and one school in Italy. However, due to an unpredicted hardware error, the test in Italy was cancelled. The other three field trials have been successful. The result indicates that the prototype controller can make substantial energy savings without compromising the thermal comfort. In the office building in Germany the side by side test with an almost identical building show over 14% savings compared to the existing compensated controller.

In the UK field trials, over 15% energy saving is observed in the office building and 10% in the hospital using a methodology for short-term comparison on the basis of Degree-days. Overall the result is very consistent with the simulation study and the test in the ICITE test building. 11. Based on the problems with the prototype controllers encountered in the ICITE test and the field trials, recommendations for industrial design have been made. A workshop was organised to help the industrial partner design the industrial manufacturing process. It was decided that the commercial version of the controller developed in the project should be developed in a series of modes that each accommodates a certain functionality and is applicable for a certain range of systems.

These modes have been technically specified and the design work is ongoing. Some actual products are expected to be available in the market at the beginning of the coming heating season. This report reiterates project objectives, discusses the main achievements, and identifies commercial applications for, and exploitation of, the new product.

Objectives and strategic aspects

2.1 Contribution to a sustainable environment

Conservation of fossil fuels is a major global issue in terms of supply, economic growth and environmental sustainability through the reduction of carbon dioxide, sulphur dioxide and nitrous oxides which contribute to the "Greenhouse Effect" and "Global Warming". There is a continuous need, therefore, to find ways to improve the efficiency of gas or oil fired boilers which are already installed and supplying hot water to existing heating systems. Most boilers deliver hot water satisfactorily but in most cases do so under undetected inefficient management by their existing control devices and systems. The SME partners have identified an opportunity to develop a novel boiler control technology that exploits shortcomings in the ability of most installed control systems to manage their boilers for the dedicated needs of the heating systems that they serve. All core SMEs are experts in "state-of-the-art" controls application to heating systems and as such are well placed to exploit any positive outcome of the research which is aimed at eliminating these shortcomings. Three core SMEs are capable of manufacturing devices emerging from the results of the RTD. In addition to the benefits to the above beneficiaries, the European Heating Plant Maintenance Industry has a significant end-user client base, which would benefit from the results of the RTD. Many organisations within this Sector are SMEs who would be supported by the core SMEs for training and product supply.

Two large European Heating Plant Maintenance companies were invited as Industrial Partners to participate in field research and market evaluation. The Research Feasibility study suggested that the following industrial, economic and social targets were achievable:

• 15% reduction in fuel use with boilers currently controlled by electromechanical control systems (particularly relevant in Former Eastern Bloc Countries);
• 10% reduction in fuel use with boilers controlled currently by electronic Building Management (Intelligent) Systems - the research aims to "teach " BMS systems how to recover this 10% by improved programming;
• commensurate reductions in toxic emissions with positive effects on respiratory illnesses and air pollution;
• elimination of need for adjustment of boiler control settings by end-users;
• savings generated on total capital investment with a payback for clients of less than two years;
• reduced Boiler Maintenance time and costs;
• sustained, but more efficient, use of older but robust boilers (particularly relevant in former Eastern Bloc Countries).

2.2 Aims and objectives

Currently, at an international level, most boiler controls comprise low technology solutions. However, the increased availability of low cost microprocessors opens up the potential for more sophisticated approaches. Typically, existing installed boiler controls do not make use of the detailed data available from the heating system which they serve. Even where much more sophisticated Building Management Systems (BMS) have been installed, their boiler "outstation" controllers still do not satisfactorily access and integrate such information. A large proportion of buildings contain older boilers and have no BMS and these are particularly targeted for application of the proposed technology. There is, therefore, a significant opportunity to improve the combined boiler operation and heating system performance to run more efficiently, whilst not compromising the satisfactory management of zone conditioning itself.

The technical limitations of existing boiler controllers historically relate to their reliance on single point sensing in order to maintain a given set point that caters for maximum load. Indeed, in many cases particularly with older boilers, this set point reflects internal boiler temperatures with no information taken from the heating system itself. This generally leads to inefficient operation, as it does not take account of variations in load and the effect of time lags due to transport of heat around the system.

A prototype controller using both return and flow temperature information had been tested in a feasibility study project as precursor to this project [1]. The feasibility study showed that significant energy savings could be achievable. However, since this controller had been developed empirically, its underlying science and applicability had not been established. More importantly the commissioning of the controller proved laborious and required levels of expertise and many trials and experiments that are not normally practical on site, thus limiting its application in wider geographical areas. The specific objectives of this project were as follows:

• Identify underlying theoretical basis of the existing boiler controller and its applicability to various building and heating systems.
• Improve the algorithm, if possible, to enhance energy saving capabilities of the controller.
• Develop a self-commissioning algorithm in order to de-skill its installation and commissioning and therefore enable practical application and commercial viability of the controller.
• Implement the algorithms developed in a hardware prototype controller and test control performance in real systems. Compare the control performance with current best practice in boiler control.

2.3 Cost effectiveness of the research

Uptake of the new controller technology will make a contribution to reduced fossil fuel consumption (and CO2 production) in member states (initially Italy, Germany and the UK). The results discussed above indicate some potential savings of up to 25% in buildings with no zonal control and up to 5% to 10% in well controlled buildings (e.g. ICITE Test Building and buildings with tight zone control). However, the actual magnitude of savings will depend on the uptake of this technology. Using original estimates from the Technical Annex a scenario is given below.

Using the estimated annual fuel bill savings of 2Keuro at each installation, i.e. consistent with a target 2 year simple payback based on an average unit selling price of 4Keuro, we can estimate the total impact of uptake (i.e. sales) and operation of units in member states. For each of the core industrial partners, using the annual sales figures predicted in the Technical Annex, (1600 KEuro in year 1; 2400 KEuro in Year 2; 4000 KEuro in year 3), we can calculate total savings on average annual fuel bill estimates of 800 KEuro in year 1, plus a further 1200 KEuro in year 2 and a further 2000 KEuro in year 3. Thus the total annual savings at the end of year 3 are 4000 KEuro in each core industrial partner region. Assuming the same figures for all four core partner regions gives annual savings of 16000 KEuro across Europe. Table 1 (below) helps to put this into the perspective of European-wide energy consumption.

Assuming a simple average annual fuel price of 200 Euro per TOE (gas and oil combined), then the fuel savings due to the total operating units sold by year three across Europe will be 80,000 toe. This may be compared to the total estimated annual fuel consumption (1995) of 65.8Mtoe, i.e. approximately 0.1%. We suggest that this in itself is a significant single contribution to savings. In the longer term, the feasibility study that preceded this project projected potential conservative savings of 10% resulting from the proposed technology, i.e. reductions of 1,500 MECU in value and 6.5 Mtoe of gas and oil used in European commercial and industrial heating each year.

Table 1. Estimated European Industrial & Commercial Heating Fuel Usage (1995)

References:

• International Marketing Data and Statistics (1997)
• British Petroleum Review of World Energy 1995/96
• Thermie RUE "Economic Evaluation of energy efficient projects"

2.4 Progress against schedule

Table 2 below shows the work programme schedule on a task by task basis. There were two areas of delay in WP1 and WP2 that have been accommodated in the schedule. In WP4, work in the test building has been brought forward by ICITE in task 4.1. All other items were carried out as planned. However, due to the mismatch of weather with the end date of project, and slight delay in the development of prototype, the data collection phase of field trials could only be started in November and December 2000 and continued to end February 2001.

Task no. Original Schedule (month) Type Description Actual Delivery (month) 1.1 3 Specification Data on boilers, systems and controls 8 1.2 8 Specification Report on scope of application 9 1.3 6 Software Software Building Simulator test-bed 7 1.4 6 Test rig Physical boiler / dummy heating load Building Emulator 10 1.6 9 Technical parameters Factors affecting system efficiency and relation to boiler control technology 13 2.2 5 Software Software implementation of controller algorithm 14 2.4 12 Report Key milestone on evaluation of software prototype 16 3.1 16 Hardware prototype Prototype hardware model created 18 3.3 17 Monitoring sites Monitoring sites commissioned 20 4.1 23 Draft report on data analysis Data from European field sites and Test Building analysed 26 4.3 24 Guidance Draft installation and commissioning guidance 24 4.4 24 Final reports 28

Table 2. Delivery of work programme against schedule

2.5 Comparison of achieved objectives against plans

All objectives have been successfully completed namely:

1. The existing controller was documented and its energy saving potential assessed.
2. The existing manual commissioning method was documented and an automatic commissioning procedure was developed and implemented in software and later in hardware de-skilling the commissioning of the existing controller.
3. A new controller on the basis of a new algorithm was developed called OWT (see later) and tested successfully. A second algorithm called TEAC (see below) was also developed but because of its need of an external temperature sensor, was not fully developed on the advice of industrial partners.
4. Auto-commissioning algorithm for OWT was developed, implemented in software and tested.
5. A new controller on the basis of OWT controller and self commissioning algorithm was implemented in hardware and tested on the test rig, and ICITE test building.
6. Four prototype controllers were produced and tested on the test rig and then sent for test at field trial locations in UK, Italy and Germany.

PLEASE NOTE

The remainder of this report has been withheld until the patenting process is complete