Heat Pump Controls to Exploit the Energy Flexibility of Building Thermal Loads

Heat Pump Controls to Exploit the Energy Flexibility of Building Thermal Loads
Author: Thibault Péan
Publisher: Springer Nature
Total Pages: 213
Release: 2021-01-04
Genre: Technology & Engineering
ISBN: 3030634299

This book describes different control strategies adapted to heat pumps, at the purpose of increasing energy flexibility in buildings. It reports on the development of both simple rule-based controls (RBC) and advanced model predictive controls (MPC). These are tested and compared in both simulation and experimental setups. The book analyzes in detail all the different steps, including the development and tuning of the controllers, their testing in experimental settings and simulation studies. Bridging between advanced control systems theory concepts and practical needs, and discussing the advantages and main challenges of MPC and RBC controllers in terms of efficiency of heat pump operation, electricity prices, emission values, and users’ comfort, this book offers an in-depth evaluation of innovative control strategies applied to energy demand management in buildings.

Heat Pump Controls to Exploit the Energy Flexibility of Building Thermal Loads

Heat Pump Controls to Exploit the Energy Flexibility of Building Thermal Loads
Author: Thibault Péan
Publisher:
Total Pages: 0
Release: 2021
Genre:
ISBN: 9783030634308

This book describes different control strategies adapted to heat pumps, at the purpose of increasing energy flexibility in buildings. It reports on the development of both simple rule-based controls (RBC) and advanced model predictive controls (MPC). These are tested and compared in both simulation and experimental setups. The book analyzes in detail all the different steps, including the development and tuning of the controllers, their testing in experimental settings and simulation studies. Bridging between advanced control systems theory concepts and practical needs, and discussing the advantages and main challenges of MPC and RBC controllers in terms of efficiency of heat pump operation, electricity prices, emission values, and users' comfort, this book offers an in-depth evaluation of innovative control strategies applied to energy demand management in buildings.

Development and Assessment of a Hierarchical Control Strategy for Electric-Thermal Systems in Household Energy Supply

Development and Assessment of a Hierarchical Control Strategy for Electric-Thermal Systems in Household Energy Supply
Author: Tanja Manuela Kneiske
Publisher: BoD – Books on Demand
Total Pages: 210
Release: 2024-01-01
Genre: Technology & Engineering
ISBN: 3737611793

Future energy infrastructure requires efficient and flexible residential energy systems. Model predictive control (MPC) enables optimized behavior by considering energy predictions. This study focuses on minimizing cost and uncertainties using MPC in electric- thermal systems. In addition a hierarchical control approach is proposed and evaluated through simulation in a new software framework called OptFlex and a laboratory experiment. The control system combines electricity and heat components for flexible and efficient energy production and consumption. It enables cost-effective and CO2 minimal utilization and a simple solution of accounting for the differences between forecasted and measured values of the energy components. The MPC is validated in a laboratory test for a PV-CHP system. Results show reliable control with a deviation of approximately 12%. The study also investigates a variable combined control variant to save computation time but incurs higher operating costs. The developed hierarchical control system effectively flexibilities, addresses uncertainties and can be applied to different energy systems including heat pumps.

Optimizing the Operation of a Hybrid Ground Source Heat Pump System Under Uncertainty

Optimizing the Operation of a Hybrid Ground Source Heat Pump System Under Uncertainty
Author: Hansani Weeratunge
Publisher:
Total Pages: 0
Release: 2021
Genre:
ISBN:

Hybrid renewable energy systems that combine conventional heating, ventilation, and air conditioning (HVAC) systems and ground source heat pumps (GSHP) have become an attractive alternative for conventional HVAC systems due to their higher cost and energy efficiency.Furthermore, control strategies that exploit predictive information about weather and building occupants' activity can further reduce the system operating costs. This study proposes a Stochastic Model Predictive Control (SMPC) for hybrid GSHP systems considering the stochastic nature of the building space heating demand. In SMPC, near-optimal control decisions are found for the current and future states of the system through the application of Regression Monte-Carlo techniques. We compare the performance of SMPC to that gained by using setpoint Control (SPC) and Model Predictive Control (MPC) which uses a deterministic forecast. It is found that by taking uncertainty into account via SMPC, the operating cost reduction compared to SPC is approximately equal to half of the cost-optimality gap between SPC and an idealized controller that is represented by MPC with perfect future information. Furthermore, we find that MPC using a forecast based on expected values leads to greater operating costs compared to the simpler SPC strategy when variability and uncertainty are present.

Dynamic Modeling and Control of Hybrid Ground Source Heat Pump Systems

Dynamic Modeling and Control of Hybrid Ground Source Heat Pump Systems
Author: Chang Chen
Publisher:
Total Pages: 0
Release: 2008
Genre:
ISBN:

Ground source heat pump (GSHP) systems are one of the fastest growing applications of renewable energy in the world with annual increases of 10% over the past decade. GSHPs are potentially more efficient than conventional air-to-air heat pumps as they use the relatively constant temperature of the geothermal energy to provide heating or cooling to conditioned rooms at desired temperature and relative humidity. More importantly, GSHP systems can in fact achieve significant energy savings year round, compared to conventional HVAC systems. A hybrid ground source heat pump (HGSHP) system is designed in this study to heat and cool an office building all the year round. Dynamic models of each component of the heat pump system are developed for simulations of heat transfer between each component of the HGSHP system and for control strategy design and analysis. A detailed multiple-load aggregation algorithm (MLAA) is adapted from the literature to precisely account for and calculate the transient heat conduction in vertical ground heat exchangers with different yearly, monthly, and daily pulses of heat. Feedback PI controllers for heat pump units and On/Off controllers for boiler and cooling tower are designed and utilized to match anticipated building loads and to analyze transient response characteristics of such outputs as water flow rate and air flow rate of heat pumps, return water temperature and supply air temperature of heat pumps, water temperatures of ground loops and heat exchangers, water temperature of boiler or cooling tower, and fuel flow rate of boiler. Control strategies for the HGSHP system in both heating and cooling modes of operation are also introduced to study the system responses. With the usage of On/Off controllers and well-tuned PI controllers, as well as optimal control strategies for heating and cooling operations, the HGSHP system is expected to give better operating performance and efficiency. As a result, noticeable energy savings can be achieved in both heating and cooling modes of operation.

Design of Phase-Change Thermal Storage Device in a Heat Pump for Building Electric Peak Load Shaving: Preprint

Design of Phase-Change Thermal Storage Device in a Heat Pump for Building Electric Peak Load Shaving: Preprint
Author:
Publisher:
Total Pages: 0
Release: 2022
Genre:
ISBN:

Replacing carbon-intensive fossil fuel heating systems with electric heat pumps powered by renewables is a promising approach to decarbonize the building sector. However, one of the technical barriers of this approach is the large scale of heat demand, which will put excessive stress on the electricity grid. Integrating thermal energy storage (TES) into the heating systems can help alleviate this problem, by shifting thermal load and thus shaving peaks in the building electric load. Therefore, it is critical to understand how to design a thermal storage device in a heat pump for peak load shaving. In this study, we developed a numerical model for a cascaded vapor compression heat pump system integrating a phase change thermal storage device. This novel system can control the net thermal charging and discharging rate of the TES independently from the building's thermal load, which allows for precise control of electric power use. In the current study, we controlled the system to shave building electric peak load during a cold winter morning, and to charge TES during the relatively warm afternoon while still providing space heating. We used the model to evaluate the system performance with and without peak shaving. We also investigated the effect of PCM transition Tt on the peak reduction and electric energy saving potentials. The results show that peak shaving scheme effectively reduces the peak electric power consumption during a predefined discharge time window. When comparing to the no shaving case, for PCM Tt = 10 degrees C, the peak electric load reduction is 23.5%. When comparing to an air-source heat pump with back up electric heater, as Tt increases from 0 to 20 degrees C, the peak reduction increases from 46.1% to 50.9%. Integrating PCM Tt = 10 degrees C with peak shaving leads to the 45.5% of electric energy saving, which is the highest among the three transition temperatures.

Demand-side Flexibility in Smart Grid

Demand-side Flexibility in Smart Grid
Author: Roya Ahmadiahangar
Publisher: Springer Nature
Total Pages: 66
Release: 2020-05-08
Genre: Technology & Engineering
ISBN: 9811546274

This book highlights recent advances in the identification, prediction and exploitation of demand side (DS) flexibility and investigates new methods of predicting DS flexibility at various different power system (PS) levels. Renewable energy sources (RES) are characterized by volatile, partially unpredictable and mostly non-dispatchable generation. The main challenge in terms of integrating RES into power systems is their intermittency, which negatively affects the power balance. Addressing this challenge requires an increase in the available PS flexibility, which in turn requires accurate estimation of the available flexibility on the DS and aggregation solutions at the system level. This book discusses these issues and presents solutions for effectively tackling them.

Integrated Modelling and Analysis of a Heat Pump BIPV/T System with Thermal Storage for Load Shifting

Integrated Modelling and Analysis of a Heat Pump BIPV/T System with Thermal Storage for Load Shifting
Author: Rémi Dumoulin
Publisher:
Total Pages:
Release: 2019
Genre:
ISBN:

This thesis presents an integrated model and methodology to quantify and demonstrate the thermal exibility potential of a residential building featuring an air-based building integrated photovoltaic thermal (BIPV/T) system coupled to an air-source heat pump and a water-based sensible thermal energy storage. A BIPV/T system is used to preheat outdoor air drawn under the PV with a fan, in addition to producing solar electricity. The pre-heated air leaving the BIPV/T cavity in the heating season is sent to the evaporator coil of the air-source heat pump so as to increase its coe cient of performance. The condenser side of the heat pump is connected to a water thermal energy storage from which water is fed to a hydronic air-system used for space heating. An integration with a thermal energy storage as a means of decoupling the loads from the source is proposed with the objective of shifting thermal loads and electrical peak demand so that they are outside the peak demand periods for the grid. A model was developed and a case study of a residential net-zero energy solar building was simulated in TRNSYS. Rule-based control strategies and a deterministic electrical grid state schedule were used to optimize the pro le of the electric demand of the building. The exibility potential of di erent design alternatives and control strategies were quanti ed using load matching grid interaction indicators, energy metrics, and di erent pricing schemes. The gross energy consumption of the building was reduced by more than 40% during peak grid events, the overall coe cient of performance of the air-source heat pump was improved by 22%, and the cost of electricity was decreased by 46% with the implementation of a variable tari price structure and a net-metering agreement.

A Reinforcement Learning Characterization of Thermostatic Control for HVAC Demand Response and Experimentation Framework for Simulated Building Energy Control

A Reinforcement Learning Characterization of Thermostatic Control for HVAC Demand Response and Experimentation Framework for Simulated Building Energy Control
Author: Christopher J. Eubel
Publisher:
Total Pages: 0
Release: 2022
Genre: Electron tubes
ISBN:

The U.S. electrical grid is in a transformation from centralized generation sources and unidirectional flow of power, to distributed networks of utility-scale and on-site renewable generation, energy storage, and flexible demand. As the electrical grid adopts more intermittent renewable energy sources, the challenges to maintaining grid stability and meeting electricity demand will only increase. The variable generation of intermittent sources combined with the existing variations in daily and seasonal electricity demand could create situations where maintaining sufficient capacity and managing distribution is often infeasible. With renewable energy aside, the grid can still struggle to meet and manage peak loads, often resorting to quick-acting, dirty “peaker” plants to compensate for supply. These peak loads are not only a challenge for supply, but also require infrastructure to be sized for such capacity. Demand-side management, or demand response, incorporate the objectives and incentives for consumers to manage their own electricity demand throughout the day so as to reduce peak loads and support grid stability. The incentives for demand response participation are often provide through the dynamic pricing of electricity. By targeting cheaper prices throughout the day, consumers can minimize their energy expense while simultaneously satisfying demand response objectives. However, this coordinated use of electricity requires flexible loads, and heating, ventilation, and air conditioning systems is one such load of particular interest. Thermal inertia of buildings and favorable weather conditions allow for its flexible use, and its energy intensiveness and rising usage around the world make it an important load to consider. Although, coordinating such loads as to maintain comfortable indoor climate and satisfy demand response objectives is not so easily done, and it is a contradictory task. In this thesis we employ a deep reinforcement learning approach to thermostatic control of HVAC to maintain thermal comfort and maximize demand response participation. We utilize EnergyPlus building energy simulation as a testbed for experimentation of reinforcement learning control. However, we see that for a number of reasons this problem and environment is challenging for the reinforcement learning framework. We address and characterize these challenges encountered from experimentation. We also present a reinforcement learning framework that utilizes a native tool of EnergyPlus which allows the implementation of custom control on running simulations. This framework allows reinforcement learning researchers and practitioners to easily interface with any configured EnergyPlus building model for the experimentation of building energy control. This platform, along with the characterization of reinforcement learning in this environment, provide a baseline for accelerating further research in this space of building energy control for dynamically priced demand response participation.