Pool Heating System Research Articles

Multi-objective optimization of energo-enviro-economic indicators of an outdoor swimming pool heating system: an approach with advanced computational techniques

Multi-objective optimization of energo-enviro-economic indicators of an outdoor swimming pool heating system: an approach with advanced computational techniques

Procuring flexibility in power systems with incentive-based grid access requests

Demand-side flexibility is an important tool for enhancing the interaction of renewable energy resources and reducing the need for grid upgrades. To employ this flexibility as a market product, it is necessary to aggregate and coordinate by coordinating responsive loads. In this regard, designing effective load coordination mechanisms that consider the preferences of aggregators, end-users, and network operators is critical for the successful implementation of demand response (DR) programs. This paper proposes an incentive-based method for coordinating a group of controllable devices that is practical, does not require complex, high-order models of the entire system, respects end-users privacy and quality of service (QoS), and can readily incorporate network conditions to ensure grid reliability. The proposed method includes algorithms at both the end-user level for controllable device operation and the aggregator level for managing the grid access requests. These algorithms are fast and with low computational burden which makes them suitable for the designed framework, reduces the implementation cost and increases the chance of scalability. The method is illustrated with a realistic test system consisting of a set of controllable heat pumps used in pool heating systems and uncontrollable loads placed in a distribution feeder and supplied by a distribution substation transformer. Simulation results highlight the effectiveness of the proposed method in satisfying the controllable device, end-users, and grid constraints. Comparing the results with similar existing methods shows that the method is 11% more cost-effective than traditional ON/OFF methods while reducing the number of rejected grid access requests from the devices, significantly.

A stochastic methodology to exploit maximum flexibility of swimming pool heating systems

Swimming pool heating systems are known as one of the best flexible resources in buildings. However, they can be flexible only for a certain number of hours throughout a day due to the comfort constraints of the users. In this study, a new approach is proposed to determine a group of contract hour sets to procure maximum flexibility of swimming pool heating systems supplied by heat pumps for trading in the regulation market while respecting the comfort of users. The main advantage of the contract hour sets is the certainty in response to flexibility requests. The proposed approach consists of three main steps. First, a stochastic mixed-integer linear program is proposed to find the optimal operation of a swimming pool heating system that has agreed to provide flexibility in a contract hours set. Then, a metric is proposed to evaluate the effectiveness of contract hour sets using the results obtained in the first step. Finally, an algorithm is proposed to identify a group of the most efficient contract hour sets using the calculated metric. The proposed approach is validated through comprehensive simulation studies for a summerhouse with an indoor pool heated by a heat pump. Also, a cost–benefit analysis is performed to examine the feasibility of these contract hour sets from financial viewpoint. Simulation results show that the maximum contract hours can vary from 2 to 12 h depending on the building occupation pattern and the minimum payment to owners is between 0.03 to 0.06 (Euro/kW).

Feasibility Study of Using Solar Thermal Energy for Heating Swimming Pools in Central European Climate (Hungary as a Case Study)

Heating swimming pools using electrical elements is costly and causes environmental impact by producing CO2 emissions. While renewable energy, such as solar energy, proves a viable alternative source for swimming pool heating. This article aims to simulate various Solar Domestic Hot Water (SDHW) systems in cold climates like Central European countries to define the best system for swimming pool heating. Three different systems were compared: a solar heating system without auxiliary heating or heat exchanger (B6), with a heat exchanger (B6.1) and with a heat exchanger and an auxiliary heating source (B6.2). Also, five crucial variables were chosen, along with the variation of the other parameters using the response surface method (RSM). This system optimisation aims to define an optimal system with less financial expenditure. It was found that the best system is B6, represented by Experiment No 25, which indicates the Collector type: flat plate collector (FPC), pool depth: 1 m, pool temperature: 26 ℃, pool covers, and windshield are actively operated. We used the T*SOL Valentine Software-2018 (kWh) to measure the solar contribution for each case. For each vector, our coded values range from [-1, +1]. The formula 2k (25=32 experiments) defines the number of experiments, where k is a vector number. In addition, two more experiments were done to define second-degree non-linear coefficients with a pool depth (B) of 1.5 m and 28 ℃ pool temperature. These two additional experiments, however, had no impact on our results. Finally, the swimming pool heating systems suitable for this weather were compared. This experiment can help the locals to find the optimal swimming pool heating system for their pools.

Heating performance of swimming pool incorporated solar assisted heat pump and underground thermal energy storage tank: A case study

In this study, utilizing a renewable energy system was proposed to eliminate conventional sources used for swimming pool heating applications. The proposed configuration mainly consisted of a private swimming pool, ground source heat pump, buried energy storage tank, and solar collectors. The solution of transient heat transfer around the storage tank and energy equations for the other configurations are integrated with MATLAB software to develop an analytical model. Analytical model was used to detect the most suitable swimming pool heating system parameters offering a reasonable heating performance year-round as well as to evaluate different performance parameters of the system. The typical meteorological data of Gaziantep city was embedded into the developed computer program to find reasonable water temperatures, solar collector area, suitable tank volume, and time to arrive at periodic conditions. The results showed that when the area of the pool was simulated at 50 m2, the underground thermal energy storage tank volume equated to 300 m3, while the collector area became 100 m2, and the periodic operation was equal to 6 years. Finally, the results showed that the swimming pool heating system derived the majority of its total energy requirement from solar energy (being 86.18%), in addition to utilizing the heat pump (being 13.82%), during the first year of operation.

A study on the integration of air-source heat pumps, solar collectors, and PCM tanks for outdoor swimming pools for winter application in subtropical climates

ABSTRACT This study presents a new integration of air-source heat pumps, solar collectors, and phase change material tanks regarding the dynamics of outdoor swimming pools, and investigates its application in outdoor swimming pools to extend their availability in the winter in subtropical climates. Since multiple heat sources are used, two issues in the development are addressed: (1) main component sizing and (2) multi-criterion design. The sizing problem is solved by considering the complementarity of different heating sources, while the multi-criterion design considers the initial investment, thermal comfort, operating costs, and energy use. Using TRNSYS and MATLAB combinations of different solar collector areas, air-source heat-pump heating capacities, and PCM tank volumes were investigated and analysed, among which optimal design was identified using a multi-criterion method. The proposed main components sizing and the multi-criterion design method could guide the design of a swimming pool heating system with multiple heat sources.

Assessment of factors influencing the energy and water performance of aquatic centres

Aquatic centres are unlike any other type of buildings in terms of energy and water consumption. Aquatic centres can expend around seven times more energy for every square metre of building area compared to an average commercial office building and consume as much as 1,000 million litres of water each year. There has been insufficient research that examines the energy performance and water usage of aquatic centres worldwide compared to other types of buildings. Also, there are very limited studies that modelled an entire aquatic centre that has multiple indoor pools within a pool hall. The main difficulty is to model the interaction of water evaporation with the mechanical equipment which is not able to be controlled by most of the energy modelling software. Using the indoor swimming pool module integrated into the surface heat balance procedures in EnergyPlus 8.7, this paper investigates the factors that influence the energy and water performance of an aquatic centre in Victoria, Australia. Detailed information about the building envelope, electromechanical systems and operational data have been obtained from the aquatic centre. The model is calibrated against measured energy and water data (utility bills obtained from the aquatic centre). Parametric studies of several energy and water efficient features are undertaken. The simulation results revealed that the incorporation of solar pool-heating systems resulted in 15.4% energy reduction and the use of vacuum filters for backwash water usage resulted in 20% water reduction. Through creating detailed procedures and processes, this paper demonstrates that an aquatic centre can be modelled successfully despite its noted complexity.

A multi-objective optimal design method for thermal energy storage systems with PCM: A case study for outdoor swimming pool heating application

Traditional design methods for thermal energy storage systems (TES) with phase change material (PCM) are mostly based on worst-case scenario, which causes too large size of main components. Current optimal design methods for these systems mainly focus on single optimization objective, which only satisfies the unilateral requirement. A multi-objective optimal design method for these systems is urgently needed, and therefore this paper remedies this knowledge gap. The response surface methodology is adopted to develop the surrogated models of the optimization objectives to improve the computational efficiency. Then, the non-dominated sorting genetic algorithm II is used to perform the double-objective and triple-objective optimization for acquiring the Pareto optimal solutions. Finally, the final decision-making methods that includes LINMAP and TOPSIS are adopted to identify the final optimal solutions. A case study of optimizing the design for an outdoor swimming pool (OSP) heating system with PCM storage tank, is conducted to illustrate the proposed approach. Eight final optimal solutions were identified, and the s p of the system in these solutions was 1.05, 1.24, 1.04, 1.22, 1.06, 1.06, 1.07, and 0.88 years, respectively. Results indicate that the proposed approach is effective to conduct the multi-objective optimization for the OSP heating systems and guide the design optimization for the TES systems with PCM.

Techno-economic optimization of open-air swimming pool heating system with PCM storage tank for winter applications

Feasible heating systems have been designed to increase the availability of open-air swimming pools in winter in subtropical climate regions. However, the approach to optimally size the main components of the system from multiple aspects is lacking. A techno-economic optimization method for swimming pool heating systems is proposed here. Minimizing the lifecycle cost of the system while ensuring the thermal comfort of the pool are considered as the optimization objectives. The volume of phase change material storage tank and the heating capacity of air-source heat pumps are selected as design variables. To improve computational efficiency, surrogate models are developed using the response surface approach, in which the dataset is generated from the simulation platform established using MATLAB and TRNSYS. Generic algorithm and non-dominated sorting genetic algorithm II are adopted to conduct single-objective and double-objective optimizations, respectively. Case studies indicate that optimal combinations for the size of main components can be identified using the proposed optimization approach. The energy and economic performance of the heating system are enhanced after optimization. The proposed techno-economic optimization method provides an instructive guideline for the optimal design of swimming pool heating systems.

Experimental study of a solar pool heating system under lower flow and low pump speed conditions

Abstract The operation of an unglazed, open-loop, solar-collector for residential pool heating was investigated experimentally under various flow conditions. The objective was to examine if solar pool collectors can be operated at lower flow conditions to minimize the pump energy while still providing sufficient thermal energy output to heat the pool. The system consists of a 20.5 m2 plastic tube, solar collector and a 36 m2 in-ground open-air pool. Key parameters were monitored over 38 days to validate a steady state model. The model achieved a good fit against the measured data and was used to simulate the system performance under various scenarios. Operating the system at low pump speed with a mass flow rate per unit collector area ( m ˙ / A C ) of 0.016 kgs−1m−2 was found to be optimal and achieved 60% pump energy savings. The coefficient of performance was increased by 2.5 times without compromising the thermal performance of the system in comparison to the Business as Usual (BAU) case. The optimal m ˙ / A C is approximately 50% of the lower limit specified by International and Australian Standards. Assuming all systems in Australia were operated under optimal conditions, annually 180 GWh of electricity consumption and 150 kilotonnes of CO2 emissions could be avoided.

Assessment and modelling of the viability of a solar heating system for aquatic centres in southern Australia

Aquatic centres are large users of energy for water and space heating with an energy intensity which can be up to seven times that of a commercial office building in Australia. Much of the energy is used to heat water to relatively low temperatures, and therefore, solar energy technology is capable of providing this energy. In the residential sector, solar thermal systems for heating water and swimming pools are well-established. This is not the case for commercial swimming pools i.e. aquatic centres. In Australia, a program to encourage commercial pool operators to install solar systems was funded in the early 1980s. This paper has investigated the current use of and attitudes to solar systems in commercial pools through a survey of municipal pool operators in Victoria, southern Australia. The survey found that there has been very little increase in the use of solar energy and that perceived barriers to the use of the technology remain the same as they were nearly 30 years ago. Lack of roof area, poor payback periods and an inability of solar to meet pool heating needs are the most common misconceptions. The paper investigates these misconceptions by analysing the hot water needs of a large aquatic centre in Melbourne. It was found that there was sufficient roof area to accommodate a solar system that would provide a solar fraction of 0.60 and the simple payback period for a solar system using unglazed solar collectors was approximately 6.7 years at current gas prices. These are predicted to rise significantly making solar energy an even more attractive proposition for commercial pool heating. Failure of past incentives to stimulate the uptake of solar pool heating systems necessitates a revised approach. Key stakeholders (industry bodies, local governments, pool operators, manufacturers, relevant HVAC consultants and research organisations) all need to be involved in an exemplar project to demonstrate the technology’s viability for aquatic centres.

Thermal analysis and modeling of a swimming pool heating system by utilizing waste energy rejected from a chiller unit of an ice rink

This study deals with the thermal analysis and modeling of a swimming pool heating system in which the waste energy rejected from the chiller unit of an ice rink is used as an energy source. The system consists of a swimming pool and an ice rink coupled by a chiller unit. The swimming pool and the ice rink both indoor types and were constructed in city of Gaziantep, Turkey. The thermal energy requirement for each section is determined by thermal analysis of each component of the system. Effects of different design parameters such as ceiling insulation thickness, ceiling emissivity, Carnot efficiency factor and size of the ice rink on the thermal energy requirements and coefficient of performance of the chiller unit are investigated. As a result of analyses of the system, the minimum ice rink area is determined in order to meet annual total heat energy demand of the olympic-sized swimming pool.

Performance of a swimming pool heating system by utilizing waste energy rejected from an ice rink with an energy storage tank

This study deals with determining the long period performance of a swimming pool heating system by utilizing waste heat energy that is rejected from a chiller unit of ice rink and subsequently stored in an underground thermal energy storage (TES) tank. The system consists of an ice rink, a swimming pool, a spherical underground TES tank, a chiller and a heat pump. The ice rink and the swimming pool are both enclosed and located in Gaziantep, Turkey. An analytical model was developed to obtain the performance of the system using Duhamel’s superposition and similarity transformation techniques. A computational model written in MATLAB program based on the transient heat transfer is used to obtain the annual variation of the ice rink and the swimming pool energy requirements, the water temperature in the TES tank, COP, and optimum ice rink size depending on the different ground, TES tank, chiller, and heat pump characteristics. The results obtained from the analysis indicate that 6–7years’ operational time span is necessary to obtain the annual periodic operation condition. In addition, an ice rink with a size of 475m2 gives the optimum performance of the system with a semi-Olympic size swimming pool (625m2).

Swimming Pool heating systems: A review of applied models

Swimming pool heating that is both efficient and ecological has become increasingly important to the development of new technologies and initiatives to protect the environment. This article, therefore, outlines previous research on the subject, acquired primarily from secondary sources and filtered based on criteria such as relevance, credibility, consistency, and applicability. Our goal is to provide an overview of the current literature and point out less-developed areas where research could be expanded. The results of the various studies suggest a widespread disagreement over calculating evaporation and make clear the need to generate integrative models that standardize this calculation.

Transient Analytical Model of a Solar-Assisted Indoor Swimming Pool Heating System

AbstractThis study deals with the thermal performance of a solar-assisted heating system for the Jordan University of Science and Technology indoor Olympic swimming pool. Solar heating is accomplished by using hot water generated by heat exchange with the solar evacuated tube collector working fluid. A transient analytical approach has been adopted for developing an explicit expression for the pool temperature, including all thermal losses. Detailed computations have been made from the beginning of September until the end of May. The effect of relevant parameters such as collector area, heat removal factors, collector heat loss coefficient, and evaporation losses on the performance of the proposed systems is investigated. The effect of covering the pool has been manifested in the analysis to reduce heat losses. The percentage of primary energy savings is used to measure the performance of the system. It is found that using a collector area equal to 53% of the pool surface results in 100% savings in primar...

Computational evaluation of solar heating systems using concrete solar collectors

This paper uses the F-chart technique to evaluate three types of solar heating systems, namely; space solar heating and domestic hot water system (SHDHW), domestic hot water system (DHW) and solar swimming pool heating system (SPHS), using three types of concrete solar collectors, models A, B, and C, and one conventional metallic solar collector. The economical analysis of SHDHW system revealed that the concrete collectors provided about 49 and 63% of the annual load when the collecting area of the solar panel increased from 55 to 88 M 2 (25 to 40% of the building roof area). The corresponding solar contributions when conventional metallic collectors were used are 41 and 53%, respectively. This represents an improvement of the annual solar fraction of about 19% when concrete collectors are used instead of the metallic collectors. It was found that solar heating systems with concrete solar collector models gave higher solar fractions and total life cycle savings than the conventional solar metallic collector.

Performance analysis of a solar-assisted swimming pool heating system

This paper deals with feasibility studies for a solar-assisted heating system for the University of Miami's Aquatic Center using the simulation program TRNSYS. The Aquatic Center is composed of an outdoor olympic size swimming pool and locker room building. The solar heating is accomplished by employing hot water generated by heat exchange with the solar collector working fluid. Two thermal storage tanks are employed for the collector and domestic use. The performance of the system is analyzed from both thermodynamic and economic standpoints and general conclusions are reached.

Energy-conservation measures for indoor swimming pools

We present a methodology for estimating heat losses for indoor swimming pools and energy savings associated with the adoption of selected energy-conservation strategies and devices in natatoriums. Although results are given for selected geographic locations, the methodology is generally applicable. Energy-conservation measures that reduce ventilation requirements are the most effective in decreasing energy costs for heating natatoriums. Pool covers are shown to save energy when the installation is accompanied by lower ventilation rates. At the present time, commercially available solar pool-heating systems are not economical for the climate of St. Louis compared to heating with natural gas but are marginally competitive with oil-fired heating systems.