scholarly journals A More Realistic Heat Pump Control Approach by Application of an Integrated Two-Part Control

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2752
Author(s):  
Maximilian Schulz ◽  
Thomas Kemmler ◽  
Julia Kumm ◽  
Kai Hufendiek ◽  
Bernd Thomas
Keyword(s):  
Heat Pump ◽  
System Integration ◽  
Integrated Approach ◽  
Energy System ◽  
Heat Pumps ◽  
Full Detail ◽  
Pump Operation ◽  
Control Approach ◽  
Ghg Reduction ◽  
Smart Control

Heat pumps are a vital element for reaching the greenhouse gas (GHG) reduction targets in the heating sector, but their system integration requires smart control approaches. In this paper, we first offer a comprehensive literature review and definition of the term control for the described context. Additionally, we present a control approach, which consists of an optimal scheduling module coupled with a detailed energy system simulation module. The aim of this integrated two-part control approach is to improve the performance of an energy system equipped with a heat pump, while recognizing the technical boundaries of the energy system in full detail. By applying this control to a typical family household situation, we illustrate that this integrated approach results in a more realistic heat pump operation and thus a more realistic assessment of the control performance, while still achieving lower operational costs.

scholarly journals OPERATION ANALYSIS OF THE AIR-SOURCE HEAT PUMP USING TRNSYS SIMULATION TOOL

2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Gabrielė Daugirdaitė ◽  
Giedrė Streckienė ◽  
Tomas Kropas
Keyword(s):  
Heat Pump ◽  
Real Data ◽  
Cold Season ◽  
Heat Pumps ◽  
Climatic Data ◽  
Pump Operation ◽  
Operation Analysis ◽  
Air Source Heat Pump ◽  
Heating Capacity ◽  
Heating Mode

In order to achieve ambitious goals for energy efficiency and requirements for near zero energy buildings, various technological solutions enabling the use of renewable energy are proposed and applied. One such rapidly spreading technology is heat pumps. However, the use of air-­to-­water heat pumps in countries where the cold season is cold and humid has unfavourable conditions for the operation of this equipment during the heating season. As a result, the performance efficiency of the equipment decreases. This article presents the simulation results of an air-­to-­water heat pump operation in Lithuania using the TRNSYS modelling tool; its nominal heating capacity is 6.55 kW. The model was calibrated using real data obtained at Vilnius Gediminas Technical University when measurements were performed under heat pump freezing conditions. The seasonal performance factor of the heat pump heating mode was determined during the calculation. Parametric analysis of the model was also performed, when sensitivity of the model to the initial climatic data was observed. Comparable results are obtained for Vilnius, Prague and London.

scholarly journals Design of Heat-Pump Systems for Single- and Multi-Family Houses using a Heuristic Scheduling for the Optimization of PV Self-Consumption

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1118 ◽  
Author(s):  
Thomas Kemmler ◽  
Bernd Thomas
Keyword(s):  
Heat Pump ◽  
Residential Buildings ◽  
Electricity Consumption ◽  
Heating System ◽  
Energy System ◽  
Heat Pumps ◽  
Photovoltaic System ◽  
Pv System ◽  
New Buildings ◽  
Floor Heating

Heat pumps in combination with a photovoltaic system are a very promising option for the transformation of the energy system. By using such a system for coupling the electricity and heat sectors, buildings can be heated sustainably and with low greenhouse gas emissions. This paper reveals a method for dimensioning a suitable system of heat pump and photovoltaics (PV) for residential buildings in order to achieve a high level of (photovoltaic) PV self-consumption. This is accomplished by utilizing a thermal energy storage (TES) for shifting the operation of the heat pump to times of high PV power production by an intelligent control algorithm, which yields a high portion of PV power directly utilized by the heat pump. In order to cover the existing set of building infrastructure, 4 reference buildings with different years of construction are introduced for both single- and multi-family residential buildings. By this means, older buildings with radiator heating as well as new buildings with floor heating systems are included. The simulations for evaluating the performance of a heat pump/PV system controlled by the novel algorithm for each type of building were carried out in MATLAB-Simulink® 2017a. The results show that 25.3% up to 41.0% of the buildings’ electricity consumption including the heat pump can be covered directly from the PV-installation per year. Evidently, the characteristics of the heating system significantly influence the results: new buildings with floor heating and low supply temperatures yield a higher level of PV self-consumption due to a higher efficiency of the heat pump compared to buildings with radiator heating and higher supply temperatures. In addition, the effect of adding a battery to the system was studied for two building types. It will be shown that the degree of PV self-consumption increases in case a battery is present. However, due to the high investment costs of batteries, they do not pay off within a reasonable period.

Analysis of an Integrated Thermal Energy System for Applications in Cold Regions

2021 ◽  
pp. 1-32
Author(s):  
Bismark Addo-Binney ◽  
Wahid Besada ◽  
Martin Agelin-Chaab
Keyword(s):  
Heat Pump ◽  
Pump Energy ◽  
Energy System ◽  
Heat Pumps ◽  
Environmental Data ◽  
Coefficient Of Performance ◽  
Space Heating ◽  
Cold Regions ◽  
Heating Capacity ◽  
Better Than

Abstract This paper performed analyses on a proposed direct wind-powered heat pump integrated with a pond which serves as an evaporator for space heating in cold regions. The analysis was conducted using environmental data for selected locations in Canada and the Engineering Equation Solver. Three different pairings of heat pumps and wind turbines were studied (a wind-powered heat pump with a pond as an evaporator, a wind-powered heat pump without a pond, and an electricity-powered heat pump). Energy and exergy analyses were performed on the systems. The novelty in the present study is in the use of a wind turbine to directly power the heat pump and using a pond as the evaporator. The results show that the proposed system has the highest coefficient of performance compared to the others. The average coefficient of performance for the selected locations is 2.7, which is at least 67% better than the others. Similarly, the overall exergy for the proposed system is 16.9%, which is at least 40% better than the others. The average heating capacity of the selected locations for the proposed system is 4.5 kW, which is from 29% to 300% better than the others. Additionally, the sustainability index for the proposed system is the highest for the proposed system. The results have shown that the proposed system has superior overall performance for space heating in cold regions.

scholarly journals Design and integration of heat pumps for nZEB in IEA HPT Annex 49

2019 ◽  
Vol 111 ◽  
pp. 04007
Author(s):  
Carsten Wemhoener ◽  
Simon Buesser ◽  
Lukas Rominger
Keyword(s):  
Heat Pump ◽  
System Integration ◽  
Heat Pumps ◽  
Field Monitoring ◽  
Building Envelope ◽  
Climate Conditions ◽  
Building Technology ◽  
Calculation Results ◽  
And Control ◽  
New Buildings

Heat pumps are a promising building technology, especially for nearly Zero Energy Buildings (nZEB) to be introduced in the EU by the beginning of 2021 for all new buildings. Despite heat pumps already range among the most efficient heat generators, further efficiency and cost optimisation is seen in system integration as well as in adapted design and control for the application in nZEB. IEA HPT Annex 49 investigates heat pump application in nZEB by simulation and field monitoring in order to evaluate integration options with other building technologies, thermal and electrical storages, the building envelope and the ground. Moreover, design and control for the loads in nZEB and the integration of nZEB into connected energy grids are considered. The investigations are accompanied by field monitoring of heat pumps in different nZEB applications and climate conditions in order to relate calculation results to the real operation and identify optimisation potentials. Expected results of the Annex 49 are recommendations regarding heat pump integration options and related design and control as well as real world heat pump performance in monitored nZEB. The paper gives an overview on the Annex 49 project and national contributions and will present first interim results of the Annex Tasks.

scholarly journals Empirical evaluation of energy profiles of thermally-efficient homes with smart energy systems and controls

2021 ◽  
Vol 2042 (1) ◽  
pp. 012023
Author(s):  
Rajat Gupta ◽  
Johanna Morey
Keyword(s):  
Heat Pump ◽  
Energy Demand ◽  
Empirical Evaluation ◽  
Heat Pumps ◽  
Peak Period ◽  
Baseline Phase ◽  
Control Phase ◽  
Electricity Use ◽  
Smart Energy Systems ◽  
Smart Control

Abstract Smart control technologies are beginning to be deployed in homes to optimise heating and alter the timing of domestic energy demand to enable residential demand side response (DSR). This paper presents before (baseline phase) and after (control phase) evaluation of the monitored indoor temperature and energy demand during the heating season in 10 new-build dwellings, each of which received a 5kWh electro-chemical battery and smart control to enable shifting of heating energy demand. The dwellings had air source heat pumps (ASHP) and 2kWp solar photovoltaic (PV) panels, and were located in a social housing estate in Barnsley, England. For eight dwellings, heat pump electricity use per heating degree day was found to decrease by 10% and narrow baseline peaks were suppressed during the control phase. Daily mean grid electricity import and heat pump electricity use in the peak period (4pm – 7pm) were measured as 4.0 kWh and 1.4 kWh during the control phase as compared to 3.8kWh and 1.3 kWh for the baseline phase. However the use of a flat tariff (single-rate) meant that battery charging-discharging capability was not fully utilised. Time-of-use tariff would further enhance cost savings associated with the change in the timing of energy demand.

scholarly journals Optimal Power Dispatch in Energy Systems Considering Grid Constraints

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 192
Author(s):  
Alejandro Rubio ◽  
Frank Schuldt ◽  
Peter Klement ◽  
Karsten von Maydell
Keyword(s):  
Unit Commitment ◽  
Control Strategies ◽  
Energy Systems ◽  
Energy System ◽  
Heat Pumps ◽  
Optimal Operation ◽  
Unit Commitment Problem ◽  
Pump Operation ◽  
Study Planning ◽  
Electrical Vehicles

As a consequence of the increasing share of renewable energies and sector coupling technologies, new approaches are needed for the study, planning, and control of modern energy systems. Such new structures may add extra stress to the electric grid, as is the case with heat pumps and electrical vehicles. Therefore, the optimal performance of the system must be estimated considering the constraints imposed by the different sectors. In this research, an energy system dispatch optimization model is employed. It includes an iterative approach for generating grid constraints, which is decoupled from the linear unit commitment problem. The dispatch of all energy carriers in the system is optimized while considering the physical electrical grid limits. From the considered scenarios, it was found that in a typical German neighborhood with 150 households, a PV penetration of ∼5 kWp per household can lead to curtailment of ∼60 MWh per year due to line loading. Furthermore, the proposed method eliminates grid violations due to the addition of new sectors and reduces the energy curtailment up to 45%. With the optimization of the heat pump operation, an increase of 7% of the self-consumption was achieved with similar results for the combination of battery systems and electrical vehicles. In conclusion, a safe and optimal operation of a complex energy system is fulfilled. Efficient control strategies and more accurate plant sizing could be derived from this work.

scholarly journals Operational optimisation of a heat pump system with sensible thermal energy storage using genetic algorithm

2018 ◽  
Vol 22 (5) ◽  
pp. 2189-2202 ◽  
Author(s):  
Christoph Schellenberg ◽  
John Lohan ◽  
Laurentiu Dimache
Keyword(s):  
Heat Pump ◽  
Emission Reduction ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Demand ◽  
Carbon Intensity ◽  
Electricity Prices ◽  
Pump System ◽  
Heat Pump System ◽  
Co2 Intensity

Heating and cooling account for 50% of global energy consumption and 40% of energy related CO2 emissions. Progress towards renewable heating has been slow, and Ireland is expected to miss European Union 2020 emission reduction and renewable energy targets. While increased wind penetration since 2005 has reduced the carbon intensity of Ireland?s electricity by 29%, carbon intensity per used floor area is more than twice the European average, amplifying air pollution, climate change, and energy security issues. The heating and electricity sectors can benefit from the successful transition to cleaner, lower carbon electricity by electrifying heating. Electricity-driven heat pumps deliver 3-4 units of heat per unit of electricity consumed, there by offering a 76% emission reduction compared with fossil-fuelled heating. This research offers an opportunity to minimise both running cost and emissions, assisting the end user and the environment. This is achieved using the smart grid to charge a thermal store during favourable low-cost times and discharge as required later. Smart, information and communication technology-integrated, adaptive control with artificial intelligence optimises the heat pump schedule based on information from forecasting services and/or predictions of heat demand, heat pump source quality, stored heat and day-ahead electricity prices. Another opportunity is the potential to assist the electricity grid by reducing peak electricity demand as smart control favours low electricity prices and low CO2 intensity that coincide with the availability of cheap (wind) electricity. Demand is shifted from expensive peak demand periods, enabling the electrification of heating in a smart energy system.

scholarly journals Optimal Power Dispatch in Energy Systems Considering Grid Constraints

2021 ◽  
Author(s):  
Alejandro Rubio ◽  
Frank Schuldt ◽  
Peter Klement ◽  
Karsten von Maydell
Keyword(s):  
Unit Commitment ◽  
Control Strategies ◽  
Energy Systems ◽  
Energy System ◽  
Optimization Method ◽  
Heat Pumps ◽  
Optimal Operation ◽  
Unit Commitment Problem ◽  
Pump Operation ◽  
Electrical Vehicles

As a consequence of the increasing share of renewable energies and sector coupling technologies, new approaches are needed for the study, planning, and control of modern energy systems. Such new structures may add extra stress to the electric grid, as is the case with heat pumps and electrical vehicles. Therefore, the optimal performance of the system must be estimated considering the constraints imposed by the different sectors. In this research, a dispatch optimization method with an iterative grid constraint generation, decoupled from the linear unit commitment problem, is employed. From the considered scenarios, it was found that in a typical German neighborhood with 150 households, PV penetration of ∼5kWp per household can lead to curtailment of ∼60MWh per year due to line loading. Furthermore, the proposed method eliminates grid violations due to the addition of new sectors reducing the curtailment up to 60%. With the optimization of the heat pump operation, an increase of 7% of the self-consumption was achieved with similar results for the combination of battery systems and electrical vehicles. In conclusion, a safer and optimal operation of a complex energy system is fulfilled. Safer control strategies and more accurate plant sizing could be derived from this work.

Performance Prediction of a Sub-Slab Heat Exchanger for Geothermal Heat Pumps

1998 ◽  
Vol 120 (4) ◽  
pp. 282-288 ◽  
Author(s):  
K. Den Braven ◽  
E. Nielson
Keyword(s):  
Soil Temperature ◽  
Heat Pump ◽  
Flow Direction ◽  
Heat Pumps ◽  
Heat Extraction ◽  
Fluid Temperature ◽  
Geothermal Heat ◽  
Pump System ◽  
Pump Operation ◽  
Heat Pump System

A large portion of the installation cost of a ground-coupled heat pump system is for the excavation necessary for ground coil placement. One possible method of reducing this cost is to place the ground coils beneath the slab floor of the building. This configuration of ground coil placement has not been specifically addressed in previous research. Freezing of the soil must be avoided in such a system. To simulate the temperature response of the surrounding soil to heat pump operation, a computer model was developed which incorporates line source theory in the form of a system of rings. The fluid temperature change along the length of the coil was used to determine the distribution of the ground load throughout the ring system. The model includes an adiabatic upper boundary, seasonal soil temperature variation, and thermal interference throughout the system. Using these results, the minimum soil temperature over a season was predicted. Based on these results, design recommendations for ground coil installation are provided based on available area, soil type, heat extraction rate, depth of coil beneath the slab floor, and depth of slab floor below grade. These include recommendations for pipe spacing, flow direction, and a method to determine whether this type of system is feasible for installation in a particular location.

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.

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