Experimental Implementation of a Micro-Scale ORC-Based CHP Energy System for Domestic Applications

Because of the renewed interest in renewable energy as well as increased emphasis on alternative technologies, micropower-generating systems have attracted considerable research interest over the last decade. However, micro-scale power generation for low grade heat recovery applications, i.e. as low as 1–3 kW - for domestic use, are characterized by very low efficiencies and relatively high specific cost. For economic viability, these factors make it imperative that the heat source remains “free”, such as solar or geothermal energy. In this paper, a small-scale Organic Rankine Cycle (ORC) is presented. The small-scale ORC module was built and tested at San Diego State University lab, aimed at producing electricity and hot water from ultra-low grade heat source that can be tapped from solar collectors and low temperature exhaust heat. The system was built for economic viability and flexibility, tailored for a domestic use. The tests demonstrated that the system offered CHP capability, with electric and thermal power output suitable for a domestic application. It also offered high operational flexibility, since the scroll expander could work with a high temperature range, accommodating an even-significant drop of the heat source temperature. Therefore, it can be conveniently used to capture solar and low-temperature energy sources. The system could be produced at an overall cost of less than $3,000 (USD 2010).

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Performance Testing and Analysis of Silica Gel-Water Adsorption Refrigerator

Journal of Physics Conference Series ◽

10.1088/1742-6596/2160/1/012032 ◽

2022 ◽

Vol 2160 (1) ◽

pp. 012032

Author(s):

Hongxuan Li ◽

Tonghua Zou ◽

Qingling Hui ◽

Ting Li ◽

Walter Mittelbach

Keyword(s):

Low Temperature ◽

Heat Source ◽

Water Temperature ◽

Silica Gel ◽

Water Adsorption ◽

Cooling Capacity ◽

Hot Water ◽

Low Grade ◽

Adsorption Refrigeration ◽

Refrigeration Capacity

Abstract In recent years, adsorption refrigeration technology has attracted wide attention from experts and scholars at home and abroad due to its environmental friendliness and energy saving advantages. In order to study the effectiveness of adsorption refrigeration technology to recover low-grade energy, a silica gel-water adsorption refrigeration system was proposed, which can effectively utilize low-grade energy such as industrial waste heat. The structure and composition of the system are introduced. The operation performance of the unit is tested under different working conditions by orthogonal experimental method, and the experimental results are analyzed. The effects of hot water temperature and flow, chilled water temperature and flow on the refrigeration capacity and COP value of the system are obtained. The experimental results show that under the low-temperature heat source of 55-75°C, the cooling capacity of the system can reach 5.3-12 and the COP value can reach 0.36-0.56. Under the same hot water temperature difference, the cooling capacity and COP value of the system increase rapidly under the condition of changing the hot water temperature at low temperature, indicating that increasing the heat source temperature at low temperature has a greater impact on the system performance. Through the analysis of primary and secondary effects, it is concluded that the inlet temperature of hot water is the main factor affecting the refrigeration capacity and COP value of the system.

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An Innovative Falling Film Evaporative Cooling With Recirculation Driven by Low-Grade Heat

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4001623 ◽

2009 ◽

Vol 1 (4) ◽

Cited By ~ 1

Author(s):

S. He ◽

R. Z. Wang ◽

Z. Z. Xia ◽

B. Tian ◽

L. W. Wang

Keyword(s):

Heat Transfer ◽

Evaporative Cooling ◽

Hot Water ◽

Working Fluid ◽

Small Scale ◽

Inlet Temperature ◽

Low Grade ◽

Falling Film ◽

Film Evaporator ◽

Low Grade Heat

A falling film evaporator integrated with a recirculation tube driven by low-grade heat has been proposed to achieve a more compact and reliable system, which can be easily integrated into small-scale systems. An experimental study of the evaporative cooling of such an innovative falling film evaporator is presented. Water was used as the working fluid. The results are compared with published data for systems using mechanical pumps to circulate the fluid. Experimental investigation showed that the evaporative heat transfer coefficient of 6770–6870 W/m2 K can be achieved when the inlet temperature of the falling fluid is 29°C and the hot water entry temperature is 70°C. Detailed investigation on the effects of the driving heat source temperature and the inlet temperature of the hot water on the liquid film cooling mechanism was investigated. The results showed that for such a system, the effect of the falling film inlet temperature is more pronounced as compared with the other two parameters. Comparisons with traditional falling film evaporator with a mechanical pump indicated that the proposed integrated evaporator is more compact, reliable, and cost effective without impairing the heat transfer performance.

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Rolling membrane powered by low-temperature steam as a new approach to generate mechanical energy

Scientific Reports ◽

10.1038/s41598-020-73732-7 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Chongshan Yin ◽

Qicheng Liu ◽

Qing Liu

Keyword(s):

Water Vapor ◽

Low Temperature ◽

Combustion Engine ◽

Mechanical Energy ◽

Heat Energy ◽

Steam Engine ◽

Low Grade ◽

Human Society ◽

New Approach ◽

Low Grade Heat

Abstract How to convert heat energy into other forms of usable energy more efficiently is always crucial for our human society. In traditional heat engines, such as the steam engine and the internal combustion engine, high-grade heat energy can be easily converted into mechanical energy, while a large amount of low-grade heat energy is usually wasted owing to its disadvantage in the temperature level. In this work, for the first time, the generation of mechanical energy from both high- and low-temperature steam is implemented by a hydrophilic polymer membrane. When exposed to water vapor with a temperature ranging from 50 to 100 °C, the membrane repeats rolling from one side to another. In nature, this continuously rolling of membrane is powered by the steam, like a miniaturized “steam engine”. The differential concentration of water vapor (steam) on the two sides of the membrane generates the asymmetric swelling, the curve, and the rolling of the membrane. In particular, results suggest that this membrane based “steam engine” can be powered by the steam with a relatively very low temperature of 50 °C, which indicates a new approach to make use of both the high- and low-temperature heat energy.

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8505170 Heat pump energized by low-grade heat source

Journal of Heat Recovery Systems ◽

10.1016/0198-7593(86)90256-0 ◽

1986 ◽

Vol 6 (5) ◽

pp. vii

Keyword(s):

Heat Source ◽

Heat Pump ◽

Low Grade ◽

Low Grade Heat

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Analysis of power cycle based on cold energy of liquefied natural gas and low-grade heat source

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2003.09.010 ◽

2004 ◽

Vol 24 (4) ◽

pp. 539-548 ◽

Cited By ~ 64

Author(s):

Wang Qiang ◽

Li Yanzhong ◽

Wang Jiang

Keyword(s):

Natural Gas ◽

Heat Source ◽

Liquefied Natural Gas ◽

Low Grade ◽

Power Cycle ◽

Cold Energy ◽

Low Grade Heat

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Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC

Archives of Thermodynamics ◽

10.2478/v10173-011-0013-5 ◽

2011 ◽

Vol 32 (3) ◽

pp. 57-70 ◽

Cited By ~ 2

Author(s):

Dariusz Mikielewicz ◽

Jarosław Mikielewicz

Keyword(s):

Power Plant ◽

Low Temperature ◽

Heat Source ◽

Silicone Oil ◽

Hot Water ◽

Working Fluid ◽

Preliminary Heating ◽

Source Temperature ◽

Heat Source Temperature ◽

Steam Heat

Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC In the paper presented is a novel concept to utilize the heat from the turbine bleed to improve the quality of working fluid vapour in the bottoming organic Rankine cycle (ORC). That is a completely novel solution in the literature, which contributes to the increase of ORC efficiency and the overall efficiency of the combined system of the power plant and ORC plant. Calculations have been accomplished for the case when available is a flow rate of low enthalpy hot water at a temperature of 90 °C, which is used for preliminary heating of the working fluid. That hot water is obtained as a result of conversion of exhaust gases in the power plant to the energy of hot water. Then the working fluid is further heated by the bleed steam to reach 120 °C. Such vapour is subsequently directed to the turbine. In the paper 5 possible working fluids were examined, namely R134a, MM, MDM, toluene and ethanol. Only under conditions of 120 °C/40 °C the silicone oil MM showed the best performance, in all other cases the ethanol proved to be best performing fluid of all. Results are compared with the "stand alone" ORC module showing its superiority.

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