USING A HEAT PUMP AS AN ALTERNATIVE TO SUPPORT SOLAR COLLECTOR FOR WATER HEATING IN BRAZIL

2012 ◽  
Vol 20 (03) ◽  
pp. 1250013 ◽  
Author(s):  
ROBERTS VINICIUS DE MELO REIS ◽  
RAPHAEL NUNES OLIVEIRA ◽  
LUIZ MACHADO ◽  
RICARDO NICOLAU NASSAR KOURY

With related greenhouse effect environmental issues linked to the constant problems of the fluctuations in oil prices, the use of solar energy is an important renewable energy source. Brazil is a country which is privileged considering the high rates of solar irradiation present throughout almost the entire national territory. Nevertheless, during certain times of the year, there is a solar energy deficit, which leads solar systems to require electrical resistance support at these times. The use of electrical resistance represents 23.5% of electric energy consumption and it presents a low residential energy efficiency. The purpose of this work is an alternative technical design for reduction of electric energy consumption through the use of a solar energy system together with a generating heat pump for water heaters for households, as well as the financial feasibility study on the use of this system. One such heat pump has been designed, constructed and tested experimentally. The average performance coefficient is equal to 2.10, a low value due to the use of a hermetic reciprocating compressor. Despite this low moderate price coefficient of acquisition and installation of a heat pump, one can allow a return on investment in from 2.1 to 3.3 years, whereas the equipment has a useful life of about 20 years, this period of return on investment is interesting.

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4306 ◽  
Author(s):  
Zhongting Hu ◽  
Sheng Zhang ◽  
Wenfeng Chu ◽  
Wei He ◽  
Cairui Yu ◽  
...  

The present work investigated a solar assisted heat pump system for drying Chinese wolfberry. The kinetic characteristic was firstly analyzed through a series of lab experiments. It was concluded that the Page model was the most suitable for predicting the heat and mass transfer of the wolfberry. Based on the wolfberry kinetic model, solar collector model and chamber air model, the coupled drying system model was developed. The accuracy of the mathematic model was determined through comparing with the preliminary experimental results. The influence of operating conditions on the thermal and energy performance of the dryer for the different operating mode was discussed. The drying weight of no more than 75 kg may be preferable in the stand-alone solar drying mode, and less than 15 h was needed to be dried. The electric energy consumption in the solar assisted the heat pump drying mode was lower than that in the stand-alone heat pump mode, and it was recommended that about 50 kg of wolfberry to be dried in the solar assisted heat pump system. Compared to the autumn drying, the reduction in the electric energy consumption was around 9.1 kWh during the 11 h summer drying process. The obtained results demonstrated the feasibility of the combined system for drying wolfberry, and also can provide the basic theoretical and experimental data support for the following research.


2012 ◽  
Vol 7 (3) ◽  
pp. 23-32 ◽  
Author(s):  
Miloslav Bagoňa ◽  
Dušan Katunský ◽  
Martin Lopušniak ◽  
Marián Vertaľ

2015 ◽  
Vol 8 (1) ◽  
pp. 38-42
Author(s):  
Pengfei Si ◽  
Xiangyang Rong ◽  
Angui Li ◽  
Xiaodan Min ◽  
Zhengwu Yang ◽  
...  

As a realization of the energy cascade utilization, the regional energy system has the significant potential of energy saving. As a kind of renewable energy, river water source heat pump also can greatly reduce the energy consumption of refrigeration and heating system. Combining the regional energy and water source heat pump technology, to achieve cooling, heating and power supply for a plurality of block building is of great significance to reduce building energy consumption. This paper introduces a practical engineering case which combines the regional energy system of complex river water source heat pump, which provides a detailed analysis of the hydrology and water quality conditions of the river water source heat pump applications, and discusses the design methods of water intake and drainage system. The results show that the average temperature of cold season is about 23.5 °C, the heating season is about 13.2 °C; the abundant regional water flow can meet the water requirement of water source heat pump unit; the sediment concentration index cannot meet the requirement of river water source heat pump if the water enters the unit directly; the river water chemistry indicators (pH, Cl-, SO42-, total hardness, total iron) can meet the requirement of river water source heat pump, and it is not required to take special measures to solve the problem. However, the problem of sediment concentration of water must be solved.


2021 ◽  
Vol 13 (8) ◽  
pp. 4180
Author(s):  
Andrzej Czerepicki ◽  
Tomasz Krukowicz ◽  
Anna Górka ◽  
Jarosław Szustek

The article presents an analysis of priority solutions for trams at a selected sequence of intersections in Warsaw (Poland). An analysis of the literature has shown the topicality of this issue. A computer simulation model of a coordinated sequence of intersections was constructed. Three test scenarios were designed: the existing control system, the new coordinated fixed-time control system, and the adaptive control system with active priority. In the simulation process, detailed travel characteristics of trams and other traffic participants in a selected section were obtained for the three varying scenarios. Electric energy consumption for traction needs and pollutant emissions was then estimated for each of the variants. It was concluded that for the analyzed configuration, implementation of the adaptive priority will result in a reduction of tram time losses by up to 25%, a reduction in energy consumption by up to 23%, and a reduction in the emission of pollutants from individual vehicles by up to 3% in relation to the original variant. The conducted research may be the basis for a comprehensive method of assessing the effectiveness of applying the adaptative priority when designing new tramway lines and modernizing the existing ones.


2012 ◽  
Vol 16 (3) ◽  
pp. 131
Author(s):  
Didik Ariwibowo

Didik Ariwibowo, in this paper explain that energy audit activities conducted through several phases, namely: the initial audit, detailed audit, analysis of energy savings opportunities, and the proposed energy savings. Total energy consumed consists of electrical energy, fuel, and materials in this case is water. Electrical energy consumption data obtained from payment of electricity accounts for a year while consumption of fuel and water obtained from the payment of material procurement. From the calculation data, IKE hotels accounted for 420.867 kWh/m2.tahun, while the IKE standards for the hotel is 300 kWh/m2.tahun. Thus, IKE hotel included categorized wasteful in energy usage. The largest energy consumption on electric energy consumption. Largest electric energy consumption is on the air conditioning (AC-air conditioning) that is equal to 71.3%, and lighting and electrical equipment at 27.28%, and hot water supply system by 4.44%. Electrical energy consumption in AC looks very big. Ministry of Energy and Mineral Resources of the statutes, the profile of energy use by air conditioning at the hotel by 48.5%. With these considerations in the AC target for audit detail as the next phase of activity. The results of a detailed audit analysis to find an air conditioning system energy savings opportunities in pumping systems. Recommendations on these savings is the integration of automation on the pumping system and fan coil units (FCU). The principle of energy conservation in the pumping system is by installing variable speed drives (VSD) pump drive motor to adjust speed according to load on the FCU. Load variations FCU provide input on the VSD pumps to match. Adaptation is predicted pump can save electricity consumption up to 65.7%. Keywords: energy audit, IKE, AC


2011 ◽  
Vol 314-316 ◽  
pp. 2071-2075
Author(s):  
Jia Hai Wang ◽  
Wen Tao Gong

Discrete machine manufacture enterprises have to induce new low-carbon manufacturing model in order to solve a dilemma of mutual restraint between development and electric energy consumption. The paper presents an approach to solve JSP with the objective of minimizing the energy consumption by shortening the distance between electricity peak and valley according to theory of load shifting in electricity. The mathematical model is proposed for JSP with objective of minimizing the energy consumption and processing time of entire batch, then the idea of time division is introduced, and a solving method based on GA built-in eM-Plant is employed to verify the model and get satisfactory scheduling results.Discrete machine manufacture enterprises have to induce new low-carbon manufacturing model in order to solve a dilemma of mutual restraint between development and electric energy consumption. The paper presents an approach to solve JSP with the objective of minimizing the energy consumption by shortening the distance between electricity peak and valley according to theory of load shifting in electricity. The mathematical model is proposed for JSP with objective of minimizing the energy consumption and processing time of entire batch, then the idea of time division is introduced, and a solving method based on GA built-in eM-Plant is employed to verify the model and get satisfactory scheduling results.


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