Electric Water Heater Modeling, DR Approaches Analysis and Study of Consumer Comfort for Demand Response

With the smart energy management system household residential appliances is able to participate in the demand response events. To reduce peak load demand and complexities in the local infrastructure DR can play an important role now a days. This paper presents a study and analysis of several papers on residential EWH DR modeling and implementation. It shows an overview of analysis of the most used and recent DR models for EWH. It also shows the analysis of the used methods to model this and the used approach in several papers. Additionally, the discussed consumer comforts and obtainable benefits in several papers by participating in DR events is also shown here. The study and analysis in this paper will contribute to the future research and encourage the end users to participate in households DR events.The present work was done and funded in the scope of the following projects: H2020 DREAM-GO Project (Marie Sklodowska-Curie grant agreement No 641794); SIMOCE (ANI|P2020 17690); and UID/EEA/00760/2019 funded by FEDER Funds through COMPETE program and by National Funds through FCT.info:eu-repo/semantics/publishedVersio

Study on Thermal Performance Assessment of Solar Hot Water Systems (SHWS) in Malaysia

Solar Hot Water Systems (SHWS) are gaining popularity in Malaysia due to increasing electricity price as well as the environmental awareness of using fossil fuels. The penetration of these systems and the technologies into Malaysian markets is a welcoming development. However, there is a need for a proper rating system for solar hot water in relation to quantify the overall energy savings. In order to develop the rating systems, a study on thermal performance assessment of SHWS in Malaysia is required. Until now, there has been no method of assessing the thermal performance for these systems thus consumers have no way of assessing the economy of their SHWS. In view of this, Malaysia should be prepared for such development by supporting consumers in assessing the SHWS. Furthermore, at the national level, the contribution of this technology to the reduction of greenhouse gas emissions cannot be quantified. The main objective for this project is to study the thermal performance assessment of SHWS in Malaysia by using combined direct measurement and computer modeling or simulation method. In order to evaluate the thermal performance of the system, a computer model known as TRNSYS Simulation Program is employed whereby most of the main components which are relevant to the systems are interconnected in the model. In order to study the thermal performance of SHWS, various researches were done in order to establish reliable input parameters to be entered into the performance rating software. The rating software is develop mainly for this purpose and is discussed in detail in this report. The results for this project revealed the rating of the SHWS produced by the manufacturer based on the thermal performance achieved from the software. The principal conclusion was that although the proposed thermal performance rating calculation method has not been certified and endorsed by Malaysian government, yet the development of the thermal performance rating assessment is the first and crucial step that leads to minimize the energy performance of the SHWS. The proposed thermal performance rating will also help to quantify the energy savings and greenhouse gas emissions reduction of the systems

Customer unit substation of collective heat distribution system : Benchmark of hot water comfort test standard and methodologies

The performance assessment of dwelling heating substations in terms of level of comfort is usually studied regarding temperature overshoots, stationary temperature deviations and settling time among other parameters. In fact, several standards and test methods can be found focusing on a specific target or technology. However, these methods do not always provide clear information about hot water comfort. As a result planners, developers and customers have difficulties to compare a substation product with products using other technologies for the heating of sanitary hot water. The study investigates the compatibility of already existing methods and intends to evaluate their applicability to systems where the sanitary hot water is prepared in an instantaneous way by using a heat exchanger in a district heating substation. In order to achieve that aim, a dynamic simulation model of a test setup (using TRNSYS) has been developed. The test procedures, as well as the simulation results, are described and discussed. This analysis is expected to provide the basis for an integrated performance assessment test of this kind of devices

A design tool for sizing thermosyphon solar water heaters

Today, thermosyphon solar water heaters are the most popular type of solar water heaters for providing households with the required hot water for domestic purposes. However, sizing and designing these systems is still based on experience or on trial and errors methods, which are based more on intuition rather than scientific methods. The present study is aimed at addressing this problem (sizing thermosyphon systems) through the development of a design tool that can be used by engineers and manufacturers to arrive at optimised systems designed according to the weather and operating conditions of particular geographical locations. The design tool developed during the course of this study is based on the TRNSYS simulation programme for evaluating the thermal performance of thermosyphon systems, and on the genetic algorithm approach for the purpose of optimising selected design parameters of thermosyphon systems. A thorough literature review of the available models and software packages that are capable of evaluating the performance of thermosyphon systems has shown that the best available programme is TRNSYS, namely the component Type 45 (thermosyphon collector-storage component). However, the component Type 45 in its current form cannot be used directly for the purpose of optimisation, because this component relies on information that must be determined experimentally. This means that the component is mainly used for evaluating the thermal performance of already-made and tested systems under varying operating and climatic conditions. For this reason, two components developed in this research have been added to the TRNSYS suite to account for information that would otherwise have to be determined experimentally. The new components are: solar collector characteristics component Type 210; and pipes - tank heat loss coefficients Type 211. Furthermore, the component Type 45 is also modified to accept as, inputs, the outputs from the previous two new components. The modified component is named as modified thermosyphon component Type 245. The new components are validated experimentally and by using reports of tests conducted according to the appropriate European standard. The modified component Type 245 does not require any validation, as no changes were made in the main programme, except that of altering the experimentally-determined information from being parameters to instead being inputs in the TRNSYS terminology. The newly validated components were added to the original TRNSYS model so as to constitute a modified TRNSYS model which is used throughout this work. The modified TRNSYS model was· then used to perform a parametric study of the design parameters of thermosyphon systems. A genetic algorithm routine for constrained single objective optimisation problem was used, and the constraints are handled by using the stochastic ranking procedure. The genetic algorithm programme is combined with the modified TRNSYS model to constitute the final design tool. The design tool is used in this study to find the optimum thermosyphon system design that best suits Libyan families (as a case study in this research) according to the weather conditions of Tripoli and a simple, but representative, hot water load pattern. The design tool is shown to have significant potential, and with further development and validation would be capable of commercial application

A novel indirect control methodology for load-leveling of space heating appliances

Demand Side Management (DSM) programs provide utility companies with amethod to shift consumer electricity usages away from peak electricity hours. DSMprograms use alternative appliance usage schemes that maintain their usefulness whileproviding ancillary services for utilities. This thesis aims to develop a linear controlmethodology that can provide signicant ancillary services for utilities without re-ducing customer comfort.A prototype enclosure was built and equipped with a heater and thermalmeasuring equipment. Data was collected during a 17 hour temperature regulationexperiment using a bang-bang controller similar to those commonly used for residen-tial heating control. An experimental thermal system identication methodology wasdeveloped for online system identication. First and second order mathematical mod-els were developed for thermal system identication. The mathematical models werecalibrated using data collected experimentally and used to estimate the net thermalresistance and capacitance using system identication techniques.The enclosure system model was also used to determine if peak power couldbe reduced by slowly varying loads utilizing a dierent type of controller. Two dier-ent linear control techniques (using K-Factor and PI approaches) and the associatedpower electronics circuitry were implemented and tuned in PSpice platform. Both controller systems successfully leveled the load and reduced the peak power demand.Finally the prototype enclosure was modied to include a linear controller us-ing an available DC power supply and a buck converter power stage. The PI controlscheme was used with a 60 phase margin for smoother and faster settling charac-teristics. The phase margin was acquired using appropriate linear approximation ofsystem transfer functions. The temperature response of the experimental system wascompared to theoretical responses

Computer simulation and optimisation of solar heating systems for Cyprus

This thesis reports the results of research into the modelling and simulation of solar water and space heating for Cyprus, and the investigation of the factors concerning the optimisation of such systems. Further a number of design criteria, which can be used by consultants and designers of solar heating systems, have been established. Five solar heating system configurations have been modelled using the component models of the TRNSYS programme. They concern thermosyphon solar water heating systems, active solar water heating systems, solar space heating systems, combined solar water and space heating systems and solar assisted heat pump systems for space and water heating. These models are used to simulate the thermal performance of the systems and investigate their cost effectiveness under the weather and socioeconomic conditions of Cyprus. The results of the simulations have been used to identify the optimum design criteria for such systems in the Cyprus environment. The design criteria that have been established are concerned mainly with the solar collector and the storage tank and they are key design factors for a solar heating system. The design factors include the collector orientation and tilt angle, the collector to load factor which relates the collector surface area to the annual thermal load, the storage factor which relates the capacity of the storage tank to the collector size, the collector water flow flux, which relates the water flow rate through the collector with the collector area, and other criteria, which concern the auxiliary heat supply and the heat exchangers. For space heating systems, in addition to the above factors, a new design criterion is introduced, the collector to floor area factor, which relates the collector area to the building floor area, while for domestic hot water systems, the collector to consumer factor is used to specify the collector surface area needed for each hot water consumer in the building. This work has resulted in the publication of four papers in refereed International Journals and the presentation of three other papers at International Conferences. A list of publications is included in the Appendices