scholarly journals Rule-Based Control Strategy to Increase Photovoltaic Self-Consumption of a Modulating Heat Pump Using Water Storages and Building Mass Activation

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6282
Author(s):  
Maria Pinamonti ◽  
Alessandro Prada ◽  
Paolo Baggio
Keyword(s):  
Boundary Conditions ◽  
Heat Pump ◽  
Control Strategy ◽  
Control Strategies ◽  
Residential Buildings ◽  
Thermal Inertia ◽  
The Self ◽  
Thermal Mass ◽  
Climate Data ◽  
Rule Based

The use of photovoltaic (PV) energy in combination with heat pump systems for heating and cooling of residential buildings can lead to renewable energy self-consumption, reducing the energy required from the grid and the carbon footprint of the building uses. However, energy storage technologies and control strategies are essential to enhance the self-consumption level. This paper proposes and analyzes a new control strategy for the operation of a modulating air-source heat pump, based on the actual PV availability. The solar energy surplus is stored as thermal energy by the use of water tanks and the activation of the thermal capacitance of the building. The efficacy of the control strategy is evaluated considering different rule-based strategies, and different boundary conditions. The effect of climate data, building insulation level and thermal inertia are investigated and compared. The results show the efficacy of the proposed strategy to decrease up to 17% the amount of electricity purchased from the grid and to increase the self-consumption by 22%, considering a high-insulated building in Bolzano, Northern Italy. The thermal mass activation is found effective to increase the self-consumption of the system. Nonetheless, the achievable energy reduction depends largely on the building characteristics and the boundary conditions.

scholarly journals Demand-Side Management of Air-Source Heat Pump and Photovoltaic Systems for Heating Applications in the Italian Context

Environments ◽  
2018 ◽  
Vol 5 (12) ◽  
pp. 132 ◽  
Author(s):  
Elena Bee ◽  
Alessandro Prada ◽  
Paolo Baggio
Keyword(s):  
Heat Pump ◽  
Control Strategy ◽  
Demand Side Management ◽  
Hot Water ◽  
The Self ◽  
Electric Heater ◽  
Demand Side ◽  
Rule Based ◽  
Air Source Heat Pump ◽  
Italian Context

Matching demand profile and solar irradiance availability is necessary to meet space heating and domestic hot water needs by means of an air-source heat pump and photovoltaic system in a single-family house. Demand-side management, with smart control of the water storage set-point, is a simple but effective technique. Several studies in the literature pursue demand-side matching and self-consumption goals through system adjustments based on the model predictive control. This study proposes a rule-based control strategy, based on instantaneous photovoltaic (PV) power production, with the purpose of enhancing the self-consumption. This strategy exploits the building’s thermal capacitance as a virtual battery, and the thermal storage capacity of the system by running the heat pump to its limit when PV surplus power is available, and by eventually using an electric heater in order to reach higher temperatures. Results of annual dynamic simulations of a building and its heating system show that the proposed rule-based control strategy is able to reduce significantly the energy exchanges between the system and the grid. Despite the enlarged renewable energy share, economic analysis points out the pursuit of the self-consumption goal may lead to a diminution of the economic advantage in the Italian context (Italian weather data and the electric power pricing scheme).

scholarly journals Impact of Boundary Conditions on the Performance Enhancement of Advanced Control Strategies for a Residential Building with a Heat Pump and PV System with Energy Storage

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1413
Author(s):  
Emmanouil Psimopoulos ◽  
Fatemeh Johari ◽  
Chris Bales ◽  
Joakim Widén
Keyword(s):  
Energy Storage ◽  
Boundary Conditions ◽  
Heat Pump ◽  
Simulation Study ◽  
Control Strategies ◽  
Thermal Storage ◽  
Hot Water ◽  
Final Energy ◽  
Advanced Control ◽  
The Impact

Operational control strategies for the heating system of a single-family house with exhaust air heat pump and photovoltaic system and “smart” utilization of energy storage have been developed and evaluated in a simulation study. The main aim and novelty of this study is to evaluate the impact on the benefit of these advanced control strategies in terms of performance (energy use and economic) for a wide range of boundary conditions (country/climate, occupancy and appliance loads). Short-term weather data and historic price data for the same year as well as stochastic occupancy profiles that include the domestic hot water load are used as boundary for a parametric simulation study for the system modeled in detail in TRNSYS 17. Results show that the control using a forecast of dynamic electricity price leads to greater final energy savings than those due to the control using thermal storage for excess PV production in all of the examined locations except Sweden. The impact on self-consumption using thermal storage of heat produced by the heat pump using excess PV production is found to decrease linearly with increasing household electricity for all locations. A reduction in final energy of up to 842 kWh year−1 can be achieved just by the use of these algorithms. The net energy cost for the end-user follows the same trend as for final energy and can result in cost savings up to 175 € year−1 in Germany and Spain due to the use of the advanced control.

scholarly journals User-friendly rolling control strategy for a heat pump heating system considering building thermal inertia

2020 ◽  
Vol 2 (4) ◽  
pp. 393-403
Author(s):  
Yunfei Mu ◽  
Xianjun Meng ◽  
Lijia Du ◽  
Qian Xiao ◽  
Hongjie Jia ◽  
...  
Keyword(s):  
Heat Pump ◽  
Control Strategy ◽  
Thermal Inertia ◽  
Heating System ◽  
User Friendly

A Self-Correcting Approach for the Bending of Metal Parts

2012 ◽  
Vol 504-506 ◽  
pp. 907-912 ◽  
Author(s):  
Ulf Damerow ◽  
Mikhail Borzykh ◽  
Werner Homberg ◽  
Ansgar Trächtler
Keyword(s):  
Process Parameters ◽  
Control Strategy ◽  
Control Strategies ◽  
Testing Machine ◽  
The Self ◽  
Loop Control ◽  
Geometrical Properties ◽  
Metal Parts ◽  
Experimental Tool ◽  
The University

During the manufacture of metal parts, geometrical deviations can appear. The reasons for this can be a variation in the properties of the semi-finished product, or wear phenomena on the punch-bending machine itself or on the punch-bending tool. When geometrical deviations appear, the process parameters normally have to be adjusted manually. The choice of the most appropriate process parameters is currently based on the operator's experience. Unfortunately, this is a time-consuming and expensive procedure right at the early stages of a production scenario. In addition, the trend towards reduced part sizes with tight tolerances, made of high strength materials, is drastically increasing the requirements regarding the production process. In order to reduce the scrap rate and the setup time for production scenarios, it is necessary to implement corrective action during the process by means of a special control strategy. A self-correcting control strategy based on a closed-loop control approach is thus under development at the University of Paderborn. The first step in this strategy involved conducting simulations is to identify those process variables, e.g. the strength or the geometrical properties of the material, which have a significant influence on the process. Once correlations between input and output variables had been established, different self-correcting control strategies were set up. To validate the simulation and to test the quality of the self-correcting control strategies, a special experimental tool, mapping the most important bending operations, was constructed at the University of Paderborn. The experimental tool is equipped with an additional measurement device and can be operated on a universal testing machine. Finally, the self-correcting control strategies were tested under production conditions on the original tool in order to take any additional influences of the punch-bending machine into consideration. In this paper, recent investigations are presented that were conducted in a collaborative project at the University of Paderborn together with two industrial partners. The results of the correlation between the variables governing the process, the development of a suitable measurement method, and a first approach to a self-correcting control strategy are set out.

scholarly journals Using PCM in Two Proposed Residential Buildings in Christchurch, New Zealand

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6025 ◽  
Author(s):  
Erik Schmerse ◽  
Charles A. Ikutegbe ◽  
Amar Auckaili ◽  
Mohammed M. Farid
Keyword(s):  
New Zealand ◽  
Phase Change Materials ◽  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Inertia ◽  
Homeless People ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Simulation Software ◽  
Thermal Mass

A characteristic feature of lightweight constructions is their low thermal mass which causes high internal temperature fluctuations that require high heating and cooling demand throughout the year. Phase change materials (PCMs) are effective in providing thermal inertia to low-thermal-mass buildings. This paper aims to analyse the thermal behaviour of two proposed lightweight buildings designed for homeless people and to investigate the potential benefit achievable through the use of different types of PCM in the temperate climatic conditions of Christchurch, New Zealand. For this purpose, over 300 numerical simulations were conducted using DesignBuilder® simulation software. The bulk of the simulations were carried out under the assumption that the whole opaque building envelope is equipped with PCM. The results showed significant energy saving and comfort enhancement through the application of PCMs. The integration of PCM in single-structure components led to substantial energy savings between 19% and 27% annually. However, occupant behaviour in terms of ventilation habits, occupancy of zones, etc. remains one of the biggest challenges in any simulation work due to insufficient data.

Heat Pump Water Heater Control Strategy Optimization for Cold Climates

2015 ◽  
Author(s):  
Jayson Bursill ◽  
Cynthia A. Cruickshank
Keyword(s):  
Heat Pump ◽  
Control Strategy ◽  
Control Strategies ◽  
Thermal Storage ◽  
Hot Water ◽  
Space Heating ◽  
Cold Climates ◽  
Water Heater ◽  
Water Heaters ◽  
Surrounding Space

Commercially available heat pump water heaters (HPWH) have been used successfully in warm humid climates (southern United States), and recently, have been proven effective in replacing electric water heater technology in cooler climates within Canada. Using an air source HPWH unit within a dwelling can yield electrical coefficients of performance that are indicative of significant energy savings, but can also add an additional load to the space heating system. Current control strategies do not attempt to mitigate the heating load added to the surrounding space, and only consider the water temperature in the tank. This is because, to date, the primary application has been in sub-tropical climates where cooling is frequently beneficial. Starting in 2015, the US Department of Energy is mandating that all electric water heaters have an energy factor (unit of heat applied to hot water per unit of energy applied to the system) greater than 2, which makes technologies that utilize electrical coefficients of performance, such as HPWH technology, mandatory. To ease the inevitable transition to heat pump water heaters in lieu of electric water heaters, modified control strategies that highlight using thermal storage to reduce space heating loads must be implemented. This paper presents a study which was conducted to evaluate the performance of a commercially available HPWH with modified controls. The HPWH is first characterized experimentally under a series of different thermal conditions and draw parameters. The test tank contains a 1500 W electric auxiliary heater that provides on demand heat to the top 0.30 m (1 ft) of the tank, and a wraparound heating coil. An air source heat pump, using R-134A as the refrigerant, draws air from, and returns air to the surrounding space and provides heating to the whole tank through the coil. The tank has been tested using Canadian Standards Association draw profiles to characterize performance under different hot water demands. Electricity consumption and thermal flux is measured for each vertical tank section, and various performance metrics are calculated using energy balances. A TRNSYS model is then calibrated to the experimental data to allow for the flexibility of varying multiple parameters over various climates. Using this calibrated TRNSYS model, an optimal control strategy and tank set-points can be determined for use in cold climates. As expected from previous work, there is a decrease in performance of the heat pump when heating the tank to higher temperatures to facilitate thermal storage, but the benefits from taking advantage of shifting electrical demand (of water heating) to space heating demand can outweigh the loss of performance.

scholarly journals Using PCM in two proposed residential buildings in Christchurch, New Zealand

2020 ◽  
Author(s):  
Erik Schmerse ◽  
Charles Ikutegbe ◽  
Amar Auckaili ◽  
Mohammed Farid
Keyword(s):  
New Zealand ◽  
Energy Saving ◽  
Phase Change Materials ◽  
Residential Buildings ◽  
Thermal Inertia ◽  
Homeless People ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Simulation Software ◽  
Thermal Mass

A characteristic feature of lightweight constructions is their low thermal mass which causes high internal temperature fluctuations that require high heating and cooling demand throughout the year. Phase Change Materials (PCMs) is effective in providing thermal inertia to low thermal mass buildings. The aim of this paper is to analyse the thermal behaviour of two proposed lightweight buildings designed for homeless people and to investigate the potential benefit achievable through the use of different types of PCM in the temperate climatic conditions of Christchurch, New Zealand. For this purpose, over 300 numerical simulations have been conducted using the simulation software DesignBuilder®. The bulk of the simulations were carried out under the assumption that the whole opaque building envelope is equipped with PCM. The results showed significant energy saving and comfort enhancement through the application of PCMs. Thereby, annual energy saving of over 50 % was reached for some of the PCMs considered. Additionally, the effectiveness of single, PCM-equipped structure components was investigated and substantial benefits between 19 and 27 % annual energy saving were achieved. However, occupant behaviour in terms of ventilation habits, occupancy of zones etc. remains one of the biggest challenges in any simulation work due to insufficient data.

scholarly journals Evaluation of a home-based 7-day infection control strategy for healthcare workers following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2): A cohort study

2020 ◽  
pp. 1-4
Author(s):  
Carla Benea ◽  
Laura Rendon ◽  
Jesse Papenburg ◽  
Charles Frenette ◽  
Ahmed Imacoudene ◽  
...  
Keyword(s):  
High Risk ◽  
Infection Control ◽  
Control Strategy ◽  
Healthcare Workers ◽  
Control Strategies ◽  
Risk Exposure ◽  
Nasopharyngeal Swab ◽  
Home Based ◽  
Respiratory Coronavirus ◽  
Second Wave

Abstract Objective: Evidence-based infection control strategies are needed for healthcare workers (HCWs) following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). In this study, we evaluated the negative predictive value (NPV) of a home-based 7-day infection control strategy. Methods: HCWs advised by their infection control or occupational health officer to self-isolate due to a high-risk SARS-CoV-2 exposure were enrolled between May and October 2020. The strategy consisted of symptom-triggered nasopharyngeal SARS-CoV-2 RNA testing from day 0 to day 7 after exposure and standardized home-based nasopharyngeal swab and saliva testing on day 7. The NPV of this strategy was calculated for (1) clinical coronavirus disease 2019 (COVID-19) diagnosis from day 8–14 after exposure, and for (2) asymptomatic SARS-CoV-2 detected by standardized nasopharyngeal swab and saliva specimens collected at days 9, 10, and 14 after exposure. Interim results are reported in the context of a second wave threatening this essential workforce. Results: Among 30 HCWs enrolled, the mean age was 31 years (SD, ±9), and 24 (80%) were female. Moreover, 3 were diagnosed with COVID-19 by day 14 after exposure (secondary attack rate, 10.0%), and all cases were detected using the 7-day infection control strategy: the NPV for subsequent clinical COVID-19 or asymptomatic SARS-CoV-2 detection by day 14 was 100.0% (95% CI, 93.1%–100.0%). Conclusions: Among HCWs with high-risk exposure to SARS-CoV-2, a home-based 7-day infection control strategy may have a high NPV for subsequent COVID-19 and asymptomatic SARS-CoV-2 detection. Ongoing data collection and data sharing are needed to improve the precision of the estimated NPV, and here we report interim results to inform infection control strategies in light of a second wave threatening this essential workforce.

scholarly journals Energy Saving Potential of Radiant Floor Heating Assisted by an Air Source Heat Pump in Residential Buildings

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1321
Author(s):  
Yu-Jin Hwang ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Residential Buildings ◽  
Heating Systems ◽  
Air Source Heat Pump ◽  
Heating Capacity ◽  
Heating Loads ◽  
Radiant Floor Heating ◽  
Floor Heating ◽  
Floor Temperature

The objective of this research is to establish an appropriate operating strategy for a radiant floor heating system that additionally has an air source heat pump for providing convective air heating separately, leading to heating energy saving and thermal comfort in residential buildings. To determine the appropriate optimal operating ratio of each system taking charge of combined heating systems, the energy consumption of the entire system was drawn, and the adaptive floor surface temperature was reviewed based on international standards and literature on thermal comfort. For processing heating loads with radiant floor heating and air source heating systems, the heating capacity of radiant floor heating by 1 °C variation in floor temperature was calculated, and the remaining heating load was handled by the heating capacity of the convective air heating heat pump. Consequently, when the floor temperature was 25 °C, all heating loads were removed by radiant floor heating only. When handling all heating loads with the heat pump, 59.2% less energy was used compared with radiant floor heating only. Considering the local discomfort of the soles of the feet, the floor temperature is expected to be suitable at 22–23 °C, and 31.5–37.6% energy saving compared with those of radiant floor heating alone were confirmed.

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