scholarly journals Assessing the performance and cost-competitiveness of a dual-source solar assisted heat pump in cold climates

2021 ◽  
Vol 246 ◽  
pp. 06007
Author(s):  
Jeremy Sager ◽  
Jean-Philippe Poirier

In many cold climates, the coincidence of long heating seasons as well as relatively high levels of solar insolation offer an opportunity to explore the potential for solar-assisted air source heat pumps to meet greenhouse gas reduction objectives for space and water heating systems. This paper presents the results of a detailed performance analysis based on 6 months of field test data of a pre-commercial, dual source solar-assisted heat pump. The data gathered during field-testing as well as the functionality of the system were studied extensively to develop and calibrate an hourly energy model. The model replicates the performance and operating modes of the solar-assisted air source heat pump. It allows for an hourly assessment of the energy savings, greenhouse gas reduction potential and cost competitiveness of this system as compared to other high performance HVAC systems in a variety of climate locations and archetype house loads. A parametric analysis is undertaken to assess the impact of key components on system viability. Results indicate that for some regions and archetype house loads, the dual-source solar-assisted heat pump can lead to significant energy savings and GHG emissions reductions when compared to high performing HVAC systems. These savings may enable a favorable payback period when a competitive capital cost is considered. The objective of the study was to identify locations and archetypes in which this solar-assisted heat pump topology may make sense for further development and demonstration.

Author(s):  
Shui Yuan ◽  
Michel Grabon

A water-loop heat pump system consists of a set of water-source heat pumps that are connected with a closed-loop water network, which allows heat to be injected into or extracted out of the loop water. Such a configuration is able to meet simultaneous heating and cooling demands with a heat recovery capability. This paper analyzes the impact of loop water temperature on energy performance of individual heat pumps and the whole system, demonstrates that there exists a unique loop water temperature that minimizes overall power consumption of the configuration under discussion, and proposes a strategy to find the optimal temperature, which can be implemented in a real-time application. Simulations have been conducted to verify that a significant energy savings can be achieved over conventional practice.


2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.


Author(s):  
Yahya I. Sharaf-Eldeen

This work involves measurements, analyses, and evaluation of performance of air-source heat pump water heaters (HPWHs), and their impacts on electric utility loads. Two add-on, heat pumps (HPs) rated at 7000 BTU/h (2.051 kW) and 12,000 BTU/h (3.517 kW) were utilized. The HPs were retrofitted to two 50 gal (189.3 l) electric water heaters (EWHs) with their electric heating elements removed. A third standard EWH was used for comparison. The testing setups were fully instrumented for measurements of all pertinent parameters, including inlet and outlet water temperatures, inlet and outlet air temperatures of the HPs, temperature and humidity of the surrounding air, volume of water drawn out of the storage tanks, as well as the electric energy consumptions of the systems. Performance measures evaluated included the coefficient of performance, the energy factor (EF), and the first hour rating (FHR). The HPWH systems gave EFs ranging from 1.8 to 2.5 and corresponding energy savings (and reductions in utility peak loads) ranging from 49.0% to 63.0%, approximately. The values obtained in the summer months were, as expected, somewhat higher than those obtained in the winter ones. The average values of the EFs and energy savings (and reductions in utility peak loads) were about 2.1 and 56.0%, respectively. FHR results were much lower for the HPWHs compared with those for the standard EWH. These results show that HPWHs are much more efficient compared with standard EWHs. While the average value of the EF for the EWH was about 0.92, the HPWHs yielded EFs averaging more than 2.00, resulting in annual energy savings averaging more than 50%. The results also show that HPWHs are effective at reducing utility peak loads, in addition to providing substantial cost savings to consumers.


2012 ◽  
Vol 608-609 ◽  
pp. 961-964
Author(s):  
Xia Chen ◽  
Li Wang ◽  
Li Ge Tong ◽  
Shu Feng Sun ◽  
Xian Fang Yue ◽  
...  

China is ranked as the world’s largest emitter of carbon dioxide (CO2). The CO2 emission from urban central heating (UCH) is responsible for 4.4% of China’s total CO2 emission. It is proposed that heat pump heating (HPH) could serve as a replacement for UCH to help realize energy-saving and emission-reduction goals to a greater extent. In northern China, 30% of urban building area is covered by urban decentralized heating (UDH). Replacing UDH with HPH is the current trend in China. In this paper we analyze the impact of replacing coal with heat pumps on the power generation sector in China. The results show that HPH has a positive impact on the power generation sector. By considering simultaneous replacement of UCH and UDH with HPH, the efficiency of power generation at the valley electricity time is increased by 0.512%; the ratio of peak–valley difference is decreased by 25.3%; the obtained reduction of CO2 emission cumulatively contributes to approximately 10.96% of this target.


2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt

Industrial heat pumps are heat-recovery systems that allow the temperature of waste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses of integrating backpressure turbine of a power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency of the primary fuel is calculated for different operating range of the heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperature difference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit. 


Author(s):  
Norbert Ka¨mmer

Heat pumps for residential space heating has become an increasingly important alternative to the conventional European heating systems like gas or oil burners. They offer the opportunity to reduce CO2 emission associated with heating residential homes in central and northern Europe as well as energy savings. The operational parameters for compressors in heat pumps are derived from different heat pump configurations. High compressor efficiency and a wide operating map is required so that an economically viable heat pump is achieved which meets the required operational conditions. The modifications to the basic refrigeration scroll compressor design are demonstrated. These dedicated compressor designs make it possible to achieve the required high condensing temperatures. A performance comparison with the standard compressor designs is presented and the available product range for the design of heat pump systems is shown.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 597
Author(s):  
Peru Elguezabal ◽  
Alex Lopez ◽  
Jesus Maria Blanco ◽  
Jose Antonio Chica

The building sector presents poor performance in terms of energy efficiency and is looking for effective alternatives aimed at reducing the use of fossil fuels. The facade is a key element able to harness renewable energy as an Active Solar Thermal Facade (ASTF). The main purpose of this study is the assessment of a novel design concept based on a steel sandwich panel technology. The performance of the active system will be first addressed by a parametric study in order to analyze its behavior and secondly, by describing a real case based on an experimental test by connecting the active panels to a heat pump. The study shows the impact of solar irradiation and mass flow on the thermal jump achieved, while ambient and fluid inlet temperatures are the most influencing parameters in the efficiency of the facade. When coupled to the heat pump, results from a measurement campaign demonstrate a remarkable improvement in the performance of the ASTF. The results presented provide significant proof about the benefits of a synergetic combination of both technologies—solar facades and heat pumps—as efficient alternatives for the building sector, aiming to improve energy efficiency as well as reduce their dependence on non-renewable sources.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3877
Author(s):  
Samuel Boahen ◽  
Kwesi Mensah ◽  
Selorm Kwaku Anka ◽  
Kwang Ho Lee ◽  
Jong Min Choi

The detection and diagnosis of faults is becoming necessary in ensuring energy savings in heat pump units. Faults can exist independently or simultaneously in heat pumps at the refrigerant side and secondary fluid flow loops. In this work, we discuss the effects that simultaneous refrigerant charge faults and faults associated with the flow rate of secondary fluids have on the performance of a heat pump operating in summer season and we developed a correlation to detect and diagnose these faults using multiple linear regression. The faults considered include simultaneous refrigerant charge and indoor heat exchanger secondary fluid flow rate faults (IFRFs), simultaneous refrigerant charge and outdoor heat exchanger secondary fluid flow rate faults (OFRFs) and simultaneous refrigerant charge, IFRF and OFRF. The occurrence of simultaneous refrigerant charge fault, IFRF and OFRF caused up to a 5.7% and 8% decrease in cooling capacity compared to simultaneous refrigerant charge and indoor heat exchanger secondary fluid flow rate faults, and simultaneous refrigerant charge and outdoor heat exchanger secondary fluid flow rate faults, respectively. Simultaneous refrigerant charge fault, IFRF and OFRF resulted in up to an 11.6% and 5.9% decrease in COP of the heat pump unit compared to simultaneous refrigerant charge fault and IFRF, and simultaneous refrigerant charge fault and OFRF, respectively. The developed FDD correlations accurately predicted the simultaneous refrigerant charge and faults in the flow rate of the secondary fluid within an error margin of 7.7%.


Author(s):  
Thomas Spiegelhalter ◽  
◽  
Camilo Rosales ◽  

This paper is a summary of cross-American experiences while researching and implementing a considerable energy reduction grant in three Latin American municipalities: Valdivia, Chile; Goiania, Brazil, and Port of Spain in Trinidad and Tobago. The project involves over 400 buildings in three different bioclimatic zones. The grant’s purpose is to demonstrate how no-cost or low-cost strategies could be deployed as efficient examples of energy savings and greenhouse gas reduction in municipal buildings. The program, conducted through pilot projects, has been designed to influence many other cities in the participating countries and beyond.


2021 ◽  
Vol 25 (1) ◽  
pp. 786-802
Author(s):  
Kertu Lepiksaar ◽  
Kiur Kalme ◽  
Andres Siirde ◽  
Anna Volkova

Abstract District heating has proven to be an efficient way of providing space heating and domestic hot water in populated areas. It has also proven to be an excellent way to integrate various renewable energy sources (RES) into the energy system. In Estonia, biomass covers most of the heat demand, but carbon-intensive fuels are still used to cover peaks and lows. Heat pumps can be a good solution for rural areas, as there is usually plenty of land available for heat pump facilities. In addition, heat pumps require low-grade heat sources such as ambient air, groundwater, lakes, rivers, sea, sewage water, and industrial waste heat. One of the downsides of heat pumps is the need for large investments compared to boilers fired by natural gas and biomass, and electric boilers. This study examines the impact of heat pump use on consumer prices for district heating in rural district heating networks in Estonia.


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