Designing a low-cost electricity-generating cooking stove for high-volume implementation

The PhD describes the social science and technical design of an innovative clean cooking stove that also generates electricity for use in developing countries. Key areas of learning adding to the research pool are: 1. Method for comparing costs of competing designs early in the research process before detailed design has been undertaken. 2. Use of state-of-the-art industrial design processes combined with social science investigations to direct research to meet end-user needs 3. Design of a low-cost, low thermal mass hot heat exchanger for use in thermo-acoustic engines 4. Design of a low-cost, low-mass Linear Alternator suitable for use in thermo-acoustic engines 5. Half-wave thermo-acoustic engine configuration with low-onset temperature suitable for operation with wood or dung as the fuel. 6. Use of an electrical analogue to predict unusual thermo-acoustic behaviour such as squegging and time-based pressure variations. The document is an extended abstract pulling together Riley’s 6 years of research and publications from the Score project, into one coherent theme as required by the University of Nottingham quality manual for staff engaged in research. The document describes the background of thermo-acoustics and how the project has enabled the science to progress from mainly rig-based engines to a manufacturable product. The research management process and techniques used to reduce project risk are highlighted, beginning with social science research into end-user requirements, system design, component design, testing and production cost predictions

Designing a low-cost electricity-generating cooking stove for high-volume implementation

The PhD describes the social science and technical design of an innovative clean cooking stove that also generates electricity for use in developing countries. Key areas of learning adding to the research pool are: 1. Method for comparing costs of competing designs early in the research process before detailed design has been undertaken. 2. Use of state-of-the-art industrial design processes combined with social science investigations to direct research to meet end-user needs 3. Design of a low-cost, low thermal mass hot heat exchanger for use in thermo-acoustic engines 4. Design of a low-cost, low-mass Linear Alternator suitable for use in thermo-acoustic engines 5. Half-wave thermo-acoustic engine configuration with low-onset temperature suitable for operation with wood or dung as the fuel. 6. Use of an electrical analogue to predict unusual thermo-acoustic behaviour such as squegging and time-based pressure variations. The document is an extended abstract pulling together Riley’s 6 years of research and publications from the Score project, into one coherent theme as required by the University of Nottingham quality manual for staff engaged in research. The document describes the background of thermo-acoustics and how the project has enabled the science to progress from mainly rig-based engines to a manufacturable product. The research management process and techniques used to reduce project risk are highlighted, beginning with social science research into end-user requirements, system design, component design, testing and production cost predictions

Development of a low-cost, electricity-generating Rankine cycle, alcohol-fuelled cooking stove for rural communities

This article describes a novel design and construction of a helical tube flash boiler that uses a 2kW nominal methylated spirit burner to heat an approximately 2.5m long coil of copper pipe fed by a nominal 8 bar electrically operated solenoid water pump. The final embodiment is for superheated steam to be converted to electricity and the waste exit heat from the generator used either for cooking or for ethanol pro duction for low-income families in developing countries. The performance of the flash boiler has been evaluated experimentally based on the well-known “Direct-Method”; by carefully measuring both the flow of the fuel and the steam. It found that the pressure inside the pipe can reach up to 7.4 bar and the temperature of the steam released by the flashing process can reach 255°C utilising a low-cost water pump. The research results prese nted in this paper demonstrate that flash boiler stove has a great potential for generating high-temperature steam for developing a low-cost cooking stove

Small-scale energy systems on a large-scale in developing countries

This paper reviews the barriers to large-scale use of small-scale energy systems. It places the review in the context of the size of the challenge both in terms of the numbers of people who still need access to modern energy carriers and in the levels of finance to provide this access. It concludes that the main problems related to access are not technical but are motivational, financial and institutions. The paper provides examples from around the world as to how these issues have been addresse

Suspension Design, Modeling, and Testing of a Thermo-Acoustic-Driven Linear Alternator

The Score-Stove™ generates electricity from a wood-burning cooking stove using a thermo-acoustic engine (TAE) that converts heat to sound through a linear alternator (LA). This paper introduces a prototype hemitoroidal suspension that was refined into a segmented trapezoidal shape that gave a higher cyclic life for the LA and includes a critical evaluation that compares a theoretical analysis with experimental results. The results show an improvement from the 40% efficiency of a standard loudspeaker used in reverse as an LA to 70–80% efficiency with the new suspension and a double Halbach array magnetic topology

Design and development of a low-cost, electricity-generating cooking Score-Stove™

SCORE (www.score.uk.com) a US$4M, 5 year international collaboration research project aims to improve the life quality of the 1.5 billion people worldwide who cook on an open fire and do not have access to electricity. SCORE market evaluations1 indicate that at the upper-cost target of$120 with 20 Watts of electricity 60 million people would afford the stove. At the lower-cost target of $40 and 100 Watts it would be affordable to over 1 billion people. In November 2010, a wood burning Score-Stove™ prototype successfully developed 23 watts of electricity based on a planar Thermo-Acoustic Engine (TAE) [2],[3],[4],[5],[6] design, indicating that the new Score-Stove™ is now ready to be engaged with manufacturers to gear up for volume production, and therefore to meet the social and cooking requirements of the rural poor people. The development to a large-volume, easy to manufacture, low-cost TAE cooking stove using elements of the formal design methodologies of BS 7000 and TRIZ are discussed. By breaking down the system requirements into cost targets for each module, performing rig testing, and design refinements it is believed that the upper-cost target is achievable with the right level of investment

Blowing the smoke out of the kitchen:core issues in household energy and gender

A literature search for papers on the theme “Household Energy” finds most researchers equate the term with cooking and stoves, issues strongly identified with women. However, a number of researchers have taken a broader definition (see for example Clancy, 1998, Klingshirn 2000) to encompass all the activities that take place within a household and the linkages to a much wider system of energy supply and demand. In addition, there are significant linkages between household energy and other sectors, for example, agriculture (agricultural residues as fuel source), health (lung and eye diseases, nutrition), education (children’s opportunity for after-school study) and income generation (cottage industries). These linkages also demonstrate that it is not sufficient to consider only women when addressing household energy issues but that men also play a significant role in decision making on household energy. This paper takes this broader definition as the framework in which to examine the issues around household energy from a gendered perspective

How to collect data on household energy consumption

The existence of reliable, disaggregated information on residential fuel consumption and supply is essential to the formulation of sound household energy strategies. This report presents guidelines for designing and administering household energy surveys. The report is composed of four chapters. Following the introduction, chapter 1 presents the existing methodologies and the advantages and disadvantages of each. Chapter 3 discusses household energy surveying, from survey and questionaire design through fieldwork and data processing/analysis. Finally, in chapter 4, a checklist is presented for use as a quick reference during the creation of a household energy survey.Energy and Environment,Social Analysis,Energy Conservation&Efficiency,Engineering,Transport and Environment

The Influence of Heat Input Ratio on Electrical Power Output of a Dual-Core Travelling-Wave Thermoacoustic Engine

This paper presents an analytical and experimental investigation of an electricity generator that employs a two-stage looped tube travellin -wave thermoacoustic prime-mover to deliver acoustic power from heat energy, a loudspeaker to extract electricity from sound energy and a tuning stub to compensate the changes in the acoustic field within the engine to enable close to travelling wave operation at the loudspeaker. Furthermore, the paper explains how to enhance the output power utilizing different heat input ratios through the engine cores. A well-known thermoacoustic design tool called Delta EC is used to simulate the wave propagation through the different parts of the system. The electrical power predicted from the low-cost prototype was 24.4 W acoustic power which confirms the potential for developing low-cost thermoacoustic electricity generator for heat recov ery from low-grade heat sources. The electrical power can be increased to 31.3 W using different heating power percentages through the two units. The verified experimental data shows good agreement with DeltaEC results