In the UK, power generation is achieved mostly through the combustion of fossil fuels from remote power stations at a low-efficiency rate of 40%. This can lead to a large depletion of energy resources and pollution to environment. In reality, after taking into consideration long-distance power transmission and distribution losses, the generation efficiency tends to be further reduced to around 32% at the power supply end. To combat this problem, a local and decentralised combined heat and power (CHP) system may be used to attain not only 30% electrical efficiency but also over 50% heating efficiency, which would significantly improve the energy utilisation rate. In areas with simultaneous heating and electricity demand including supermarket and district heating, such systems would be a viable economic option. However, currently most CHP systems still require fossil fuel energy resources, which diminish both their energy-saving merit and potential CO2 emission reductions. Therefore, it would be highly desirable to promote the use of localised renewable resources, such as biomass fuels, with optimised CHP system engineering designs. Currently, there are two main biomass CHP systems: biomass gasification with gas/steam turbines and biomass combustion with Organic Rankin Cycles (ORC). However, these biomass CHP systems cannot be further developed or extensively applied before the resolution of certain critical issues. These include achieving an acceptable thermal efficiency, compact system size, environmentally-friendly working fluid, advanced thermodynamic power cycles, optimal system design and control, and flexible operation etc. On the other hand, for power generation with medium to high temperature heat sources, CO2 supercritical Brayton cycles (S-CO2) can predominate over conventional ORCs in terms of thermal efficiency, environmental impact and system compactness. The S-CO2 systems have been applied in large-scale waste heat recovery of nuclear power plants but have not yet been utilised in biomass power generations due to various unsettled challenges. In this proposed project, a small-scale biomass power generation system with advanced CO2 supercritical Brayton cycles and novel heat exchanger designs will be investigated experimentally and theoretically. The investigation will address the challenges involved in the proposed system including innovative designs of thermal drive CO2 supercritical compressors, precise CO2 parameter controls at the S-CO2 compressor inlet, novel designs of supercritical CO2 heat exchangers and comprehensive understanding of the complex heat transfer and hydraulic processes involved. In addition, a detailed transient model of the biomass S-CO2 power generation system will be developed which will enable the system to be further optimised and scaled up for actual design and operation.

In the UK, power generation is achieved mostly through the combustion of fossil fuels from remote power stations at a low-efficiency rate of 40%. This can lead to a large depletion of energy resources and pollution to environment. In reality, after taking into consideration long-distance power transmission and distribution losses, the generation efficiency tends to be further reduced to around 32% at the power supply end. To combat this problem, a local and decentralised combined heat and power (CHP) system may be used to attain not only 30% electrical efficiency but also over 50% heating efficiency, which would significantly improve the energy utilisation rate. In areas with simultaneous heating and electricity demand including supermarket and district heating, such systems would be a viable economic option. However, currently most CHP systems still require fossil fuel energy resources, which diminish both their energy-saving merit and potential CO2 emission reductions. Therefore, it would be highly desirable to promote the use of localised renewable resources, such as biomass fuels, with optimised CHP system engineering designs. Currently, there are two main biomass CHP systems: biomass gasification with gas/steam turbines and biomass combustion with Organic Rankin Cycles (ORC). However, these biomass CHP systems cannot be further developed or extensively applied before the resolution of certain critical issues. These include achieving an acceptable thermal efficiency, compact system size, environmentally-friendly working fluid, advanced thermodynamic power cycles, optimal system design and control, and flexible operation etc. On the other hand, for power generation with medium to high temperature heat sources, CO2 supercritical Brayton cycles (S-CO2) can predominate over conventional ORCs in terms of thermal efficiency, environmental impact and system compactness. The S-CO2 systems have been applied in large-scale waste heat recovery of nuclear power plants but have not yet been utilised in biomass power generations due to various unsettled challenges. In this proposed project, a small-scale biomass power generation system with advanced CO2 supercritical Brayton cycles and novel heat exchanger designs will be investigated experimentally and theoretically. The investigation will address the challenges involved in the proposed system including innovative designs of thermal drive CO2 supercritical compressors, precise CO2 parameter controls at the S-CO2 compressor inlet, novel designs of supercritical CO2 heat exchangers and comprehensive understanding of the complex heat transfer and hydraulic processes involved. In addition, a detailed transient model of the biomass S-CO2 power generation system will be developed which will enable the system to be further optimised and scaled up for actual design and operation.

Lot-NET considers how waste heat streams from industrial or other sources feeding into low temperature heat networks can combine with optimal heat pump and thermal storage technologies to meet the heating and cooling needs of UK buildings and industrial processes. Heating and cooling produces more than one third of the UK's CO2 emissions and represent about 50% of overall energy demand. BEIS have concluded that heat networks could supply up to 20% of building heat demand by 2050. Heat networks have previously used high temperature hot water to serve buildings and processes but now 4th generation networks seek to use much lower temperatures to make more sources available and reduce losses. Lot-NET will go further by integrating low temperature (LT) networks with heat pump technologies and thermal storage to maximise waste and ambient heat utilisation. There are several advantages of using LT heat networks combined with heat pumps: - They can reuse heat currently wasted from a wide variety of sources in urban environments, e.g. data centres, sewage, substation transformers, low grade industrial reject heat. - Small heat pumps at point of use can upgrade temperature for radiators with minimal electricity use and deleterious effect on the electricity grid. - Industrial high temperature waste can be 'multiplied' by thermal heat pumps increasing the energy into the LT network. - By operating the heat network at lower temperatures, system losses are reduced. Heat source availability is often time dependant. Lot-NET will overcome the challenges of time variation and how to apply smart control and implementation strategies. Thermal storage will be incorporated to reduce the peak loads on electricity networks. The wider use of LT heat networks will require appropriate regulation to support both businesses and customers and Lot-NET will both need to inform and be aware of such regulatory changes. The barrier of initial financial investment is supported by BEIS HNIP but the commercial aspects are still crucial to implementation. Thus, the aim of LoT-NET is to prove a cost-effective near-zero emissions solution for heating and cooling that realises the huge potential of waste heat and renewable energies by utilising a combination of a low-cost low-loss flexible heat distribution network together with novel input, output and storage technologies. The objectives are: 1. To develop a spatial and temporal simulation tool that can cope with dynamics, scale effects, efficiency, cost, etc. of the whole system of differing temperature heat sources, distribution network, storage and delivery technologies and will address Urban, Suburban and Exurban areas. 2. To determine the preferred combination of heat capture, storage and distribution technologies that meets system energy, environmental and cost constraints. Step change technologies such a chemical heat transport and combined heat-to-power and power-to-heat technologies will be developed. 3. To design, cost and proof of concept prototype (as appropriate) seven energy transformation technologies in the first two-three years. They consist of both electrically driven Vapour Compression and heat driven Sorption technologies. Priority for further development will be then given to those which have likely future benefits. 4. To determine key end use and business/industry requirements for timely adoption. While the Clean Growth Strategy and the Industrial Strategy Challenge Fund initially support future implementation, innovative business models will reduce costs rapidly for products or services that customers want to buy and use. Thus, engagement with stakeholders and end users to provide evidence of possible business propositions will occur. 5. To demonstrate/validate the integrated technologies applicable to chosen case studies. The range of heating, cooling, transformation and storage technologies studied will be individually laboratory tested interacting with a simulated netw

In the UK, power generation is achieved mostly through the combustion of fossil fuels from remote power stations at a low-efficiency rate of 40%. This can lead to a large depletion of energy resources and pollution to environment. In reality, after taking into consideration long-distance power transmission and distribution losses, the generation efficiency tends to be further reduced to around 32% at the power supply end. To combat this problem, a local and decentralised combined heat and power (CHP) system may be used to attain not only 30% electrical efficiency but also over 50% heating efficiency, which would significantly improve the energy utilisation rate. In areas with simultaneous heating and electricity demand including supermarket and district heating, such systems would be a viable economic option. However, currently most CHP systems still require fossil fuel energy resources, which diminish both their energy-saving merit and potential CO2 emission reductions. Therefore, it would be highly desirable to promote the use of localised renewable resources, such as biomass fuels, with optimised CHP system engineering designs. Currently, there are two main biomass CHP systems: biomass gasification with gas/steam turbines and biomass combustion with Organic Rankin Cycles (ORC). However, these biomass CHP systems cannot be further developed or extensively applied before the resolution of certain critical issues. These include achieving an acceptable thermal efficiency, compact system size, environmentally-friendly working fluid, advanced thermodynamic power cycles, optimal system design and control, and flexible operation etc. On the other hand, for power generation with medium to high temperature heat sources, CO2 supercritical Brayton cycles (S-CO2) can predominate over conventional ORCs in terms of thermal efficiency, environmental impact and system compactness. The S-CO2 systems have been applied in large-scale waste heat recovery of nuclear power plants but have not yet been utilised in biomass power generations due to various unsettled challenges. In this proposed project, a small-scale biomass power generation system with advanced CO2 supercritical Brayton cycles and novel heat exchanger designs will be investigated experimentally and theoretically. The investigation will address the challenges involved in the proposed system including innovative designs of thermal drive CO2 supercritical compressors, precise CO2 parameter controls at the S-CO2 compressor inlet, novel designs of supercritical CO2 heat exchangers and comprehensive understanding of the complex heat transfer and hydraulic processes involved. In addition, a detailed transient model of the biomass S-CO2 power generation system will be developed which will enable the system to be further optimised and scaled up for actual design and operation.