Heat pumps as means of energy recovery in developing countries

1993 ◽  
pp. 71-76
Author(s):  
N.C. Srivastava ◽  
M.S. Ismail ◽  
A.G. bin Ujang
Keyword(s):  
Developing Countries ◽  
Energy Recovery ◽  
Heat Pumps

An experimental setup for the analysis of an energy recovery system from wastewater for heat pumps in civil buildings

2016 ◽  
Vol 102 ◽  
pp. 961-971 ◽  
Author(s):  
Lucio Postrioti ◽  
Giorgio Baldinelli ◽  
Francesco Bianchi ◽  
Giacomo Buitoni ◽  
Francesco Di Maria ◽  
...  
Keyword(s):  
Energy Recovery ◽  
Heat Pumps ◽  
Experimental Setup ◽  
Energy Recovery System ◽  
Recovery System

Improved µ-Scale Turbine Expander for Energy Recovery

2010 ◽  
Author(s):  
Marcus Keding ◽  
Piotr Dudzinski ◽  
Alexander Reissner ◽  
Stefan Hummel ◽  
Martin Tajmar
Keyword(s):  
High Pressure ◽  
Power Output ◽  
Energy Recovery ◽  
Turbine Blades ◽  
Low Pressure ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Work Recovery ◽  
Micro Power ◽  
Pressure Part

Micro power converters for energy recovery are increasingly important for a number of future applications. The Austrian Institute of Technology (AIT) is presently developing an innovative μ-scale turbine expander for work recovery in transcritical CO2 heat pumps. The main drawback of a lower COP (coefficient of performance) of transcritical CO2 heat pumps compared to conventional heat pump systems can be compensated by utilizing the pressure difference between the high pressure and low pressure part of the pump for work recovery. Work recovery can be realized by substituting the expansion valve between the high and low pressure side by a Pelton turbine with specific two phase flow turbine blades. In order to increase the power output, the generator was integrated into the turbine to reduce the friction losses and hence increase the overall efficiency. An important aspect is that the generator is directly connected with the high pressure part of the turbine. One part of the project is the optimization of the turbine geometry via simulation tools. The paper will give an overview about our microturbine development as well as a comparison of the power output of each turbine generation. Furthermore the present paper discusses a concept that utilizes our microturbine together with a micro combustion module that enables a micro power generator with very high power-to-weight ratios based on green fuels.

Briefing: Landfill mining for energy recovery in tropical developing countries

2018 ◽  
Vol 13 (4) ◽  
pp. 93-97 ◽  
Author(s):  
Sandro L Machado ◽  
Miriam F Carvalho ◽  
Ednildo A Torres ◽  
Átila C Santos ◽  
Mehran Karimpour-Fard
Keyword(s):  
Developing Countries ◽  
Energy Recovery ◽  
Landfill Mining

scholarly journals Field Test and Analysis of Energy-Saving Effects of Energy-Recovery Ventilators on Heat-Pump Electricity Consumption in a Classroom

2019 ◽  
Vol 11 (7) ◽  
pp. 2069
Author(s):  
Jae-Sol Choi ◽  
Eui-Jong Kim
Keyword(s):  
Energy Saving ◽  
Field Test ◽  
Energy Recovery ◽  
Field Tests ◽  
High Energy ◽  
Heat Pumps ◽  
Test Method ◽  
Actual System ◽  
Experimental Conditions ◽  
Saving Rates

Energy-recovery ventilators (ERVs) are regarded as important energy-saving systems in buildings. It has been reported that they have high energy-saving rates compared with conventional ventilators that operate without energy recovery, but the saving rates have been obtained typically by employing chamber tests and simulations. In this work, a field-test method is proposed that uses a single test room but alternates the tested ventilation modes hourly. This proposed method is useful because an additional comparison room is not always available and can be a source of uncertainty for field tests. The test is performed in a classroom during a heating period, and the results are calibrated to account for different experimental conditions during the test period. The calibrated energy-saving rates indicate the effectiveness of the ERV; however, they are lower in the early hours of the system operation, for two reasons: (1) the maximum power control schemes of the heat pumps are applied for cases where the indoor temperatures are far lower than the set-point temperature; (2) the ventilation load seemingly represents a decreasing proportion of the total heating load in early hours owing to the thermal-capacity effects for the building, which was cooled for many hours. The findings are verified via a chamber test and simulations. As a consequence, it is important to account for actual system characteristics affected by the thermal behaviors of classrooms when the overall performance of a system is evaluated.

Development of a µ-Scale Turbine Expander for Energy Recovery

2009 ◽  
Author(s):  
Marcus Keding ◽  
Piotr Dudzinski ◽  
Martin Tajmar ◽  
Reinhard Willinger ◽  
Klaus Ka¨fer
Keyword(s):  
Heat Pump ◽  
Pressure Difference ◽  
Energy Recovery ◽  
Low Pressure ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Low Flow ◽  
Working Fluid ◽  
Small Scale ◽  
Work Recovery

Waste heat is a primary source of energy loss in many applications. A number of developments around a micro rocket engine at the Austrian Research Centers (ARC) promise innovative energy recovery and micro power generation solutions. Here we focus on the investigation of micro technologies for application in HVAC (heating, ventilating, and air conditioning) systems. The use of μ-scale turbine expanders for work recovery in transcritical CO2 heat pump processes has been identified as most interesting and promising for the application in HVAC cases. One of the main drawbacks of transcritical CO2 heat pumps is the lower COP (coefficient of performance) compared to conventional heat pump systems which originates from the non isothermal heat rejection in the gas cooler. This drawback can be compensated by utilizing the pressure difference between the high pressure and low pressure part of the heat pump for work recovery. This is feasible as the pressure difference is considerably larger in case of CO2 heat pumps compared to conventional systems. Work recovery can be realized by substituting the expansion valve between the high and low pressure side by an expansion machine. Due to the low flow rate of the working fluid, the turbine type is based on the Pelton turbine with specific two phase flow turbine blades. In addition to the turbine part a magnetic coupling, miniature bearings and a small scale generator are important parts of the system. Thermodynamic simulations showed an absolute microturbine power yield between 60 W and 150 W for a 2 kW heating system.

Urban waste to energy recovery assessment simulations for developing countries

2020 ◽  
Vol 131 ◽  
pp. 104949 ◽  
Author(s):  
Afreen Siddiqi ◽  
Masahiko Haraguchi ◽  
Venkatesh Narayanamurti
Keyword(s):  
Developing Countries ◽  
Energy Recovery ◽  
Waste To Energy ◽  
Urban Waste ◽  
Recovery Assessment

scholarly journals Operational experiences of a geothermal heat pump system

2014 ◽  
pp. 115-118
Author(s):  
Imre Török
Keyword(s):  
Energy Efficient ◽  
Energy Recovery ◽  
Heat Pumps ◽  
Geothermal Heat ◽  
Pump System ◽  
Application System ◽  
Heat Pump System ◽  
Recovery System ◽  
Geothermal Heat Pump ◽  
Low Energy Buildings

Energy consumption nearly 40% operation translates of the buildings in Hungary. In the last 5–8 years we can see a breakthrough in the field of low energy buildings, increasing the demand for buildings 'energy efficient', and realized several successful investments in our country. Nowadays thanks to the application system the number of public buildings increased environmental energy recovery system has been growing such as solar power, heat pumps.

scholarly journals Energy Recovery from Wastewater: A Study on Heating and Cooling of a Multipurpose Building with Sewage-Reclaimed Heat Energy

2019 ◽  
Vol 12 (1) ◽  
pp. 116 ◽  
Author(s):  
Daniele Cecconet ◽  
Jakub Raček ◽  
Arianna Callegari ◽  
Petr Hlavínek
Keyword(s):  
Heat Exchangers ◽  
Urban Areas ◽  
Energy Recovery ◽  
Heat Recovery ◽  
Energy Requirement ◽  
Heat Pumps ◽  
Heat Energy ◽  
Heating And Cooling ◽  
Conventional Solution ◽  
The Impact

To achieve technically-feasible and socially-desirable sustainable management of urban areas, new paradigms have been developed to enhance the sustainability of water and its resources in modern cities. Wastewater is no longer seen as a wasted resource, but rather, as a mining ground from which to obtain valuable chemicals and energy; for example, heat energy, which is often neglected, can be recovered from wastewater for different purposes. In this work, we analyze the design and application of energy recovery from wastewater for heating and cooling a building in Brno (Czech Republic) by means of heat exchangers and pumps. The temperature and the flow rate of the wastewater flowing in a sewer located in the proximity of the building were monitored for a one-year period, and the energy requirement for the building was calculated as 957 MWh per year. Two options were evaluated: heating and cooling using a conventional system (connected to the local grid), and heat recovery from wastewater using heat exchangers and coupled heat pumps. The analysis of the scenarios suggested that the solution based on heat recovery from wastewater was more feasible, showing a 59% decrease in energy consumption compared to the conventional solution (respectively, 259,151 kWh and 620,475 kWh per year). The impact of heat recovery from wastewater on the kinetics of the wastewater resource recovery facility was evaluated, showing a negligible impact in both summer (increase of 0.045 °C) and winter conditions (decrease of 0.056 °C).

scholarly journals Bottled Biogas—An Opportunity for Clean Cooking in Ghana and Uganda

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3856
Author(s):  
Mairi J. Black ◽  
Amitava Roy ◽  
Edson Twinomunuji ◽  
Francis Kemausuor ◽  
Richard Oduro ◽  
...  
Keyword(s):  
Developing Countries ◽  
Circular Economy ◽  
Energy Recovery ◽  
Organic Waste ◽  
Low Cost ◽  
Small Scale ◽  
Effective Management ◽  
Grid Infrastructure ◽  
Electricity Grid ◽  
Novel Technologies

Anaerobic digestion (AD) can bring benefits in terms of effective management of organic waste, recovery of nutrients and energy recovery, and is consistent with circular economy principles. AD has been promoted and implemented worldwide, but at widely differing scales, influenced by the availability and location of feedstocks. In developing countries, feedstock arises from small- to medium-scale agriculture and agro-processing operations, as well as from household and municipal waste. Biogas produced from residues from agro-processing facilities may be used for on-site heat and power, but the lack of a gas and electricity grid infrastructure can limit opportunities to distribute gas or generated electricity to wider users. This paper presents the findings of the first study to consider novel technologies for small-scale and low-cost biogas clean-up into biomethane, and compression into small bottles, suitable as a clean cooking fuel. The paper reports on the initial evaluation of biomethane for cooking in Ghana and Uganda.

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