scholarly journals Designing, manufacturing and testing of a micro combined heat and power (micro-CHP) system

2017 ◽  
Vol 2 (3) ◽  
pp. 197-201
Author(s):  
Masood Ebrahimi ◽  
Mansour Lahonian ◽  
Sirwan Farhadi
Keyword(s):  
Heat Recovery ◽  
Tap Water ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Domestic Hot Water ◽  
Heating Source ◽  
Waste Energy ◽  
Overall Efficiency ◽  
Chp System ◽  
Main Components

In the present paper a micro-CHP is designed, built and tested based on a 5 kW diesel engine that is chosen to recover its water jacketing and exhaust waste energy and convert it into hot water. The hot water may be used as heating source or domestic hot water. Heat recovery for the lube oil, radiation, convection, and conduction to ambient is not used since they all count for only 13% of the inlet fuel energy. The results include the main characteristics in the design section, some pictures of the main components, the temperature of exhaust, water jacketing and tap water at different points of the system. In addition the heat recovery at different engine loads is also given. The experiments and results show that the overall efficiency of the CHP system can reach 60% which means more than 30% increase of efficiency when comparing with the case when only electricity was supposed to be produced by the engine.

Application of an Exhaust Heat Recovery System for Domestic Hot Water

2008 ◽  
Author(s):  
Lanbin Liu ◽  
Lin Fu ◽  
Yi Jiang
Keyword(s):  
Solar Energy ◽  
Heat Pump ◽  
Heat Recovery ◽  
Tap Water ◽  
Hot Water ◽  
Collection System ◽  
Pump System ◽  
Heat Pump System ◽  
Exhaust Heat ◽  
Exhaust Heat Recovery

Typically there is a great deal of waste heat available in drainage system of large-scale public bathhouses, such as public bathhouses in schools, barracks and natatoriums. The paper advances a heat pump system used in bathhouses for exhaust heat recovery. The system consists of solar energy collection system, drainage collection system and heat pump system for exhaust heat recovery. In the system, tap water is heated by energy from solar energy collection system, and is used as hot water for bathing at the beginning. At the same time, drainage collection system collects sewage from bathhouses, and then electric heat pump starts up and recovers the exhaust heat in sewage and heats the tap water. In this way, heat is recycled. Practical operation of the system was introduced, and drainage temperature as well as equipment capacity was optimized based on a practical example. Compared with gas-fired (oil-fired, coal-fired, electric) boilers, the system has advantages of lower energy consumption, less pollution and lower operating cost. Therefore, the system has great superiority in energy conservation and has a good application prospect.

Analytical and Experimental Study of Potential Heat Recovery From Household Refrigerators

2004 ◽  
Author(s):  
Jessica Todd
Keyword(s):  
Experimental Data ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat ◽  
Tap Water ◽  
Economic Feasibility ◽  
Hot Water ◽  
Coil Design ◽  
Waste Heat Recovery System ◽  
Recovery Potential

Opportunities for waste recovery exist in many types of industrial devices as summarized by Kreith and West [1]. However, no experimental data regarding the potential of heat recovery from household refrigerators have been published in open literature. The decision to implement a heat recovery option depends mostly on convenience and cost. In some cases, however, the decision is difficult because there is a lack of reliable information of the payback for a potential application. This article provides useful information for the design and payback of a waste heat recovery system on a household refrigerator. This paper presents experimental and analytical results of energy recovery potential from the heat rejected by the condenser coils of a household refrigerator. Using a small heat exchanger affixed to the condenser coils, the heat thus recovered can preheat domestic tap water. The analytical study considered three designs: A heat exchanger with the refrigerant condensing on the outside of water pipes, refrigerant on the inside of a counter-flow heat exchanger, and the refrigerant condensing inside a serpentine coil enclosed by a container filled with household tap water. Considering economic feasibility and manufacturing ease, the serpentine coil design was chosen. Experimental data confirmed the heat recovery possibility from the condenser coils. The serpentine coil design can achieve a payback time of 2 to 10 years dependent on whether the domestic hot water uses electric or gas heating.

scholarly journals Waste Heat Recovery from Servers Using an Air to Water Heat Pump

2021 ◽  
Vol 24 (1) ◽  
Author(s):  
Seweryn Lipiński ◽  
Michał Duda ◽  
Dominik Górski
Keyword(s):  
Heat Pump ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Domestic Hot Water ◽  
Cooling Unit ◽  
Pump Inlet ◽  
The Cost

The analysis of advisability and profitability of using an air to water heat pump for the purpose of waste heat recovery from servers being used as cryptocurrency mining rigs, was performed. To carry out such an analysis, the cooling unit of the computing server was connected to the heat pump, and the entire system was adequately equipped with devices measuring parameters of the process. Performed experiments proves that the heat pump coefficient of performance (COP) reaches satisfactory values (i.e., an average of 4.21), what is the result of stable and high-temperature source of heat at the pump inlet (i.e., in the range of 29.9-34.1). Economic analysis shows a significant reduction in the cost of heating domestic hot water (by nearly 59-61%). The main conclusion which can be drawn from the paper, is that in a case of having a waste heat source in a form of a server or similar, it is advisable to consider the purchase of air-to-water heat pump for the purpose of domestic hot water heating.

The Potential for Thermal Waste Energy Recovery in Industrial Kitchens

2017 ◽  
Author(s):  
A. P. Wemhoff ◽  
T. Dai ◽  
A. S. Fleischer
Keyword(s):  
Energy Recovery ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Payback Period ◽  
Hot Water ◽  
Pollution Reduction ◽  
Water Heater ◽  
Tube Heat Exchanger ◽  
Waste Energy

Industrial kitchens consume significant amounts of energy, largely in the form of heat production by cooking and cleaning equipment, which requires removal by the facility’s heating, ventilating, and air conditioning (HVAC) system. One potential means to improve the energy efficiency of industrial kitchens lies in the use of waste energy recovery of hot wastewater from an industrial-scale dishwasher. Examination of an on-campus dining facility suggests that waste heat recovery can occur at the facility gas hot water heater (HWH) and the dishwasher electric hot water booster (HWB). This study suggests that waste heat recovery is more financially viable in existing construction at the electric HWB, despite yielding less recovered heat than the gas HWH. A payback period of approximately two years is calculated for the installation of a 146 kW shell-and-tube heat exchanger. The corresponding annual source pollution reduction is approximately 13 kg of SO2, 6.5 kg of NOx, and 6.5 metric tons of CO2. However, new construction projects in similar building configurations could also include HWH heat recovery, resulting in a similar payback period but with more substantial annual source pollution reduction values: 14 kg of SO2, 33 kg of NOx, and 38 metric tons of CO2.

Numerical and Experimental Investigation of Electrical Efficiency Improvement of a Micro Combined Heat and Power (m-CHP) System by Modifying Cam Curve of OHVG Engine

2020 ◽  
Vol 13 (3) ◽  
pp. 203-222
Author(s):  
Fatemeh Goodarzvand-Chegini ◽  
Mohammdreza Habibi ◽  
Saeed Rakhsha ◽  
Leila Samiee ◽  
Meisam Amini ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Engine Speed ◽  
Electrical Power ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Valve Timing ◽  
Engine Torque ◽  
Electrical Efficiency ◽  
Full Load ◽  
Chp System

Background: The purpose of this research is to study the solutions for improving the efficiency of a micro combined heat and power (m-CHP) system based on OHVG (OverHead Valve Gas fueled) engine. Method: In this regard, the effects of valve timing and changing the camshaft on the power and fuel consumption of the engine have been numerically and experimentally investigated. The tests have been performed for engine speed range from 1000 rpm to 3500 rpm, while the engine's fuel was natural gas. The numerical results are found to be in good agreement with experimental ones. The effect of changing the valve timing and camshaft on the performance of the m-CHP has been investigated through the experiments in the test room. The engine speed was 1500 rpm; output hot water was fixed at 55oC; and output electrical power varies from 8 kW to 13 kW in the experiments. Results & Conclusion: The experimental results of the engine test indicate that, by changing the camshaft for full load operation and speed 1500 rpm, engine torque and volumetric efficiency improved by 7.2% and 6.0%, respectively, and fuel consumption decreased by 0.8%. According to the results, the best point for the performance of m-CHP is close to the full load of the electrical power because by increasing the electrical load, electrical efficiency increases from about 25.9% to 32.3%, while the thermal efficiency decreases from about 61.9% to 56.1%.

30-Year Life Cycle Cost of Solar Based Domestic Hot Water Systems for Ontario

2008 ◽  
Author(s):  
Gurjot S. Gill ◽  
Alan S. Fung
Keyword(s):  
Life Cycle ◽  
Natural Gas ◽  
Fuel Consumption ◽  
Life Cycle Cost ◽  
Heat Recovery ◽  
Ghg Emissions ◽  
Hot Water ◽  
Domestic Hot Water ◽  
On Demand ◽  
Gray Water

The heating of water for domestic purposes presently accounts for 24 percent of Canadian residential energy consumption (Natural Resources Canada, 2006). This energy demand is primarily met by conventional sources such as electricity, natural gas and oil. Recent changes in fuel availability and price as well as environmental concerns lead consumers to give further consideration to the use of solar energy for heating water. The objective of this paper is to simulate the different domestic hot water (DHW) systems to examine their fuel consumption, greenhouse gases (GHG) emissions, life cycle costs and pay back periods. In this case study, seventeen different DHW systems were simulated using TRNSYS as simulation engine. These include solar-based models (with electric and natural gas backup tanks), electric and natural gas tank models (with and without gray water heat recovery), on-demand and combo-boiler systems. This paper will discuss three solar-based systems in detail, however their result comparison with other systems will be discussed. Three different solar-based systems are: I) Solar pre-heat with .56 efficiency natural gas back up tank; II) Solar pre-heat with .94 efficiency electric back up tank; III) Timers (off during peak times 7am till 10 pm) with solar pre-heat and electric (.94 efficiency) secondary. Results indicate that solar alternative having timers with solar pre-heat and electric secondary gives best results in terms of annual fuel consumption ($93) and GHG emissions (266 kg). However on demand modulating gas combo boiler (0.78 efficiency) with gray water heat recovery (0.6 efficiency) has best 30-year life cycle cost ($12332).

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