scholarly journals Air-to-water heat pumps: the impact of climate, compressor technology, water output temperature and sizing on the seasonal coefficient of performance for heating

2020 ◽  
Vol 997 ◽  
pp. 012150
Author(s):  
G A Mouzeviris ◽  
K T Papakostas
Keyword(s):  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Water Output ◽  
The Impact ◽  
Compressor Technology

Sustainable energy solutions for thermal load in buildings - Role of heat pumps, solar thermal, and hydrogen-based cogeneration systems

2021 ◽  
pp. 1-25
Author(s):  
Praveen Cheekatamarla ◽  
Vishaldeep Sharma ◽  
Bo Shen
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Carbon Footprint ◽  
Energy Demand ◽  
Primary Energy ◽  
Heat Pumps ◽  
Total Carbon ◽  
Coefficient Of Performance ◽  
Renewable Energy Resources ◽  
The Impact

Abstract Economic and population growth is leading to increased energy demand across all sectors – buildings, transportation, and industry. Adoption of new energy consumers such as electric vehicles could further increase this growth. Sensible utilization of clean renewable energy resources is necessary to sustain this growth. Thermal needs in a building pose a significant challenge to the energy infrastructure. Supporting the current and future building thermal energy needs to offset the total electric demand while lowering the carbon footprint and enhancing the grid flexibility is presented in this study. Performance assessment of heat pumps, renewable energy, non-fossil fuel-based cogeneration systems, and their hybrid configurations was conducted. The impact of design configuration, coefficient of performance (COP), electric grid's primary energy efficiency on the key attributes of total carbon footprint, life cycle costs, operational energy savings, and site-specific primary energy efficiency are analyzed and discussed in detail.

scholarly journals Modelling Load Profiles of Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 766 ◽  
Author(s):  
Jochen Conrad ◽  
Simon Greif
Keyword(s):  
Heat Pump ◽  
Heat Supply ◽  
Field Tests ◽  
Energy System ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
High Temporal Resolution ◽  
Electrical Load ◽  
Ground Source Heat Pumps ◽  
The Impact

Approximately one quarter of energy-related emissions in Germany are caused by the domestic sector. At 81%, the largest share of these emissions is due to heat supply. Many measures are available to reduce these emissions. One of these measures, which is considered to play an important role in many studies, is the replacement of fossil-fired boilers with electric heat pumps. In order to be able to analyse the impact of high penetrations of heat pumps on the energy system, the coefficient of performance (COP) must be modelled with high temporal resolution. In this study, a methodology is presented on how to calculate high-resolution COPs and the electrical load of heat pumps based on thermal load curves and temperature time series. The COP is determined by the reciprocal Carnot factor. Since heat pumps are often designed bivalently due to the cost structure, the methodology described can also be used for evaluating the combination of immersion heater and heat pump (here for the air/water heat pump). As a result the theoretical hourly COPs determined are calibrated with annual performance factors from field tests. The modelled COPs show clear differences. Currently, mostly air source heat pumps are installed in Germany. If this trend continues, the maximum electrical load of the heat supply will increase more than would be the case with higher shares of ground source heat pumps.

scholarly journals Experimental Investigation of Frost Formation Influence on an Air Source Heat Pump Evaporator

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5737
Author(s):  
Tomas Kropas ◽  
Giedrė Streckienė ◽  
Juozas Bielskus
Keyword(s):  
Experimental Investigation ◽  
Heat Pump ◽  
Cold Season ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Outdoor Temperature ◽  
Operating Cycle ◽  
Frost Formation ◽  
Negative Effect ◽  
The Impact

The application of heat pumps in the heating systems of buildings in the cold or transitional season is becoming an increasingly common practice not only in Lithuania but in other countries as well. Due to the growing popularity of air-to-air or air-to-water heat pumps in the building sector, the problem of the evaporator heat exchanger freezing is also becoming more and more relevant. As the outdoor temperature drops, so does the heat pump’s coefficient of performance (COP) for heating. The freezing of the evaporator surface increases the energy consumption of the system, has a negative effect on heat exchange, distorts the normal operating cycle of the heat pump and the energy is wasted for defrosting processes. This article describes the experimental investigation of an air-to-water heat pump, presents the results obtained during the experiments and their interfaces. The experiments were carried out during the transitional/cold season. It was found that frost formation on the evaporator started when the outdoor temperature was <3.5 °C and the relative humidity reached 88%. The defrosting cycle took an average of 5 min. The impact of the evaporator freezing on the operation and COP of the heat pump was assessed.

On the Impact of Heat Pumps Electric Load on the Power Consumption of Lampedusa

2020 ◽  
Author(s):  
Marina Bonomolo ◽  
Mariano Giuseppe Ippolito ◽  
Giuliana Leone ◽  
Rossano Musca ◽  
Vincenzo Porgi ◽  
...  
Keyword(s):  
Power Consumption ◽  
Heat Pumps ◽  
Electric Load ◽  
The Impact

scholarly journals Heat Pump Bridge Analysis Using the Modified Energy Transfer Diagram

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 137
Author(s):  
Florian Schlosser ◽  
Heinrich Wiebe ◽  
Timothy G. Walmsley ◽  
Martin J. Atkins ◽  
Michael R. W. Walmsley ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Heat Pump ◽  
Heat Recovery ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Combined Application ◽  
Recovery Potential ◽  
Composite Curve ◽  
And Performance ◽  
The Individual

Heat pumps are the key technology to decarbonise thermal processes by upgrading industrial surplus heat using renewable electricity. Existing insight-based integration methods refer to the idealised Grand Composite Curve requiring the full exploitation of heat recovery potential but leave the question of how to deal with technical or economic limitations unanswered. In this work, a novel Heat Pump Bridge Analysis (HPBA) is introduced for practically targeting technical and economic heat pump potential by applying Coefficient of Performance curves into the Modified Energy Transfer Diagram (METD). Removing cross-Pinch violations and operating heat exchangers at minimum approach temperatures by combined application of Bridge Analysis increases the heat recovery rate and reduce the temperature lift to be pumped at the same time. The insight-based METD allows the individual matching of heat surpluses and deficits of individual streams with the capabilities and performance of different market-available heat pump concepts. For an illustrative example, the presented modifications based on HPBA increase the economically viable share of the technical heat pump potential from 61% to 79%.

scholarly journals Performance Evaluation of an Adsorption Heat Pump System Using MSC-30/R1234yf Pair with the Impact of Thermal Masses

2021 ◽  
Vol 11 (5) ◽  
pp. 2279
Author(s):  
Sangwon Seo ◽  
František Mikšík ◽  
Yuta Maeshiro ◽  
Kyaw Thu ◽  
Takahiko Miyazaki
Keyword(s):  
Heat Pump ◽  
Adsorption Isotherms ◽  
Coefficient Of Performance ◽  
Variable Pressure ◽  
Condensation Temperature ◽  
Relative Pressure ◽  
Pump System ◽  
Adsorption Heat Pump ◽  
Adsorbed Phase ◽  
The Impact

In this study, we evaluated the performance of low Global Warming Potential (GWP) refrigerant R1234yf on the activated carbon (MSC-30) for adsorption heating applications. The adsorption isotherms of MSC-30/R1234yf were measured using a constant-volume–variable-pressure (CVVP) method from very low relative pressure to the practical operating ranges. The data were fitted with several isotherm models using non-linear curve fitting. An improved equilibrium model was employed to investigate the influence of dead thermal masses, i.e., the heat exchanger assembly and the non-adsorbing part of the adsorbent. The model employed the model for the isosteric heat of adsorption where the adsorbed phase volume was accounted for. The performance of the heat pump was compared with MSC-30/R134a pair using the data from the literature. The analysis covered the desorption temperature ranging from 60 °C to 90 °C, with the evaporation temperature at 5 °C and the adsorption temperature and condensation temperature set to 30 °C. It was observed that the adsorption isotherms of R1234yf on MSC-30 were relatively lower than those of R134a by approximately 12%. The coefficient of performance (COP) of the selected pair was found to vary from 0.03 to 0.35 depending on the heat source temperature. We demonstrated that due to lower latent heat, MSC-30/R1234yf pair exhibits slightly lower cycle performance compared to the MSC-30/R134a pair. However, the widespread adaptation of environmentally friendly R1234yf in automobile heat pump systems may call for the implementation of adsorption systems such as the direct hybridization using a single refrigerant. The isotherm and performance data presented in this work will be essential for such applications.

scholarly journals Factors Shaping A/W Heat Pumps CO₂ Emissions—Evidence from Poland

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1576
Author(s):  
Piotr Jadwiszczak ◽  
Jakub Jurasz ◽  
Bartosz Kaźmierczak ◽  
Elżbieta Niemierka ◽  
Wandong Zheng
Keyword(s):  
Air Quality ◽  
Power System ◽  
Heat Pump ◽  
Heat Pumps ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Additional Stress ◽  
The European Union ◽  
Energy Mix

Heating and cooling sectors contribute to approximately 50% of energy consumption in the European Union. Considering the fact that heating is mostly based on fossil fuels, it is then evident that its decarbonization is one of the crucial tasks for achieving climate change prevention goals. At the same time, electricity sectors across the globe are undergoing a rapid transformation in order to accommodate the growing capacities of non-dispatchable solar and wind generators. One of the proposed solutions to achieve heating sector decarbonization and non-dispatchable generators power system integration is sector coupling, where heat pumps are perceived as a perfect fit. Air source heat pumps enable a rapid improvement in local air quality by replacing conventional heating sources, but at the same time, they put additional stress on the power system. The emissions associated with heat pump operation are a combination of power system energy mix, weather conditions and heat pump technology. Taking the above into consideration, this paper presents an approach to estimate which of the mentioned factors has the highest impact on heat pump emissions. Due to low air quality during the heating season, undergoing a power system transformation (with a relatively low share of renewables) in a case study located in Poland is considered. The results of the conducted analysis revealed that for a scenario where an air-to-water (A/W) heat pump is supposed to cover space and domestic hot water load, its CO2 emissions are shaped by country-specific energy mix (55.2%), heat pump technology (coefficient of performance) (33.9%) and, to a lesser extent, by changing climate (10.9%). The outcome of this paper can be used by policy makers in designing decarbonization strategies and funding distribution.

Modeling and Design of Building-Integrated Thermoelectrics

2011 ◽  
Author(s):  
Leon M. Headings ◽  
Gregory N. Washington
Keyword(s):  
Thermal Response ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Net Energy ◽  
Arbitrary Boundary ◽  
Heating And Cooling ◽  
Temperature Oscillations ◽  
Wall Structures ◽  
And Control

The goal of this research is to develop a framework for replacing conventional heating and cooling systems with distributed, continuously and electrically controlled, building-integrated thermoelectric (BITE) heat pumps. The coefficient of performance of thermoelectric heat pumps increases as the temperature difference across them decreases and as the amplitude of temperature oscillations decreases. As a result, this research examines how thermal insulation and mass elements can be integrated with thermoelectrics as part of active multi-layer structures in order to minimize net energy consumption. In order to develop BITE systems, an explicit finite volume model was developed to model the dynamic thermal response of active multi-layer wall structures subjected to arbitrary boundary conditions (interior and exterior temperatures and interior heat loads) and control algorithms. Using this numerical model, the effects of wall construction on net system performance were examined. These simulation results provide direction for the ongoing development of BITE systems.

Preliminary Feasibility Study of Groundwater Source Geothermal Heat Pumps in Mason County and the American Bottoms Area, Illinois

2014 ◽  
Author(s):  
Xinli Lu ◽  
David R. Larson ◽  
Thomas R. Holm
Keyword(s):  
Ground Surface ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Weather Data ◽  
Single Family ◽  
Geothermal Heat ◽  
Geothermal Heating ◽  
Heating And Cooling ◽  
Groundwater Source ◽  
Mason County

Groundwater source heat pumps exploit the difference between the ground surface temperature and the nearly constant temperature of shallow groundwater. This project characterizes two areas for geothermal heating and cooling potential, Mason County in central Illinois and the American Bottoms area in southwestern Illinois. Both areas are underlain by thick sand and gravel aquifers and groundwater is readily available. Weather data, including monthly high and low temperatures and heating and cooling degree days, were compiled for both study areas. The heating and cooling requirements for a single-family house were estimated using two independent models that use weather data as input. The groundwater flow rates needed to meet these heating and cooling requirements were calculated using typical heat pump coefficient of performance values. The groundwater in both study areas has fairly high hardness and iron concentrations and is close to saturation with calcium and iron carbonates. Using the groundwater for cooling may induce the deposition of scale containing one or both of these minerals.

scholarly journals Fault detection for air conditioning system using machine learning

2020 ◽  
Vol 9 (1) ◽  
pp. 109
Author(s):  
Noor Asyikin Sulaiman ◽  
Md Pauzi Abdullah ◽  
Hayati Abdullah ◽  
Muhammad Noorazlan Shah Zainudin ◽  
Azdiana Md Yusop
Keyword(s):  
Machine Learning ◽  
Supervised Learning ◽  
Air Conditioning ◽  
Machine Learning Algorithms ◽  
Coefficient Of Performance ◽  
Support Vector ◽  
Air Conditioning System ◽  
Learning Classifier ◽  
Negative Impacts ◽  
The Impact

Air conditioning system is a complex system and consumes the most energy in a building. Any fault in the system operation such as cooling tower fan faulty, compressor failure, damper stuck, etc. could lead to energy wastage and reduction in the system’s coefficient of performance (COP). Due to the complexity of the air conditioning system, detecting those faults is hard as it requires exhaustive inspections. This paper consists of two parts; i) to investigate the impact of different faults related to the air conditioning system on COP and ii) to analyse the performances of machine learning algorithms to classify those faults. Three supervised learning classifier models were developed, which were deep learning, support vector machine (SVM) and multi-layer perceptron (MLP). The performances of each classifier were investigated in terms of six different classes of faults. Results showed that different faults give different negative impacts on the COP. Also, the three supervised learning classifier models able to classify all faults for more than 94%, and MLP produced the highest accuracy and precision among all.

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