Heat Pump Water Research Articles

Configurational Design of a Hybrid System Based on an Air–Water Heat Pump and Biomass Boiler for a Rural Dwelling

Hybrid energy systems combine multiple energy sources and storage technologies to enhance performance and meet diverse energy needs. Hybrid heat pump systems are particularly suitable for heating and cooling buildings in rural areas. Air-source heat pumps have two well-known disadvantages during the coldest period of the year, when the building’s heating load is at its peak: the heat pump’s capacity is reduced and it needs to perform defrost cycles. A potential solution is to size the heat pump to cover only a portion of the peak load and to use a second heat generator in a hybrid heat pump system. There is a gap in the literature regarding the configurational analysis of hybrid heat pump (HHP) systems, particularly in terms of combining heat pumps and biomass boilers, and evaluating their efficiency, economic aspects, and environmental impact. Thus, in this research, a dynamic model of a HHP system, consisting of an air-to-water heat pump paired with a biomass boiler as a backup, is presented. Various configurations of the HHP system have been developed to evaluate key performance indicators, such as efficiency, emissions, operational costs, and other relevant factors. The findings of this paper indicate that the energy performance of HHP systems is significantly affected by the system layout, heat pump size, cut-off temperature, and the control algorithm used to activate the heat generators. Moreover, series operation of HHP systems is not only more efficient than parallel operation but also results in lower emissions and reduced operation costs. As expected, the energy loss associated with defrost cycles significantly impacts the overall performance of a hybrid system based on an air-source heat pump. Finally, the impact of the cut-off temperature on the key parameters in the configuration analysis was examined, and the optimal performance of the HHP system, in terms of minimizing operational costs and emissions, was depicted using a heat map diagram.

Optimizing Energy Yield and Economic Benefit of Renewable Energy Technologies for Urban Mediterranean Dwellings

Mediterranean European cities are characterized by high population density and limited space for large-scale implementation of renewable energy installations. This paper addresses the optimization of renewable energy installations in Mediterranean dwellings with the scope of increasing their energy contribution and cost-effectiveness. In a case study for Malta, the three technologies studied were solar photovoltaics, solar water heating, and heat pump water heating. Technical and economic analyses were performed on a number of reference configurations using Polysun software (version 2022.8). Sensitivity analyses were also conducted to study the impact that different technical and economic factors have on the performance of the configurations considered. Finally, comparisons were made between the techno-economic results obtained from the reference and sensitivity analyses. Based on data collected, the presence of renewable energy source (RES) technologies in the residential sector of Malta was characterized and correlated with the types of dwellings considered. Among the results obtained, it was found that although a solar RES installation may experience some shading, this does not mean that it is rendered economically unfeasible. Moreover, from the simulations conducted, electrical energy storage technology was considered as too premature unless strongly subsidized, making economic sense only in specific circumstances. On the other hand, although heat pump water heating technology is also relatively modern, it was concluded to be the most beneficial in terms of both energy yield and economic benefit, generally speaking. Furthermore, it was determined that in a higher occupancy dwelling, solar water heating (SWH) and heat pump water heating (HPWH) result in considerably more attractive energy savings.

Long-term climate-based sizing and economic assessment of air-water heat pumps for residential heating

This study presents a novel methodology for sizing air–water heat pumps (ASHP) for space heating and hot water supply in buildings. Utilizing long-term local climatic data, the developed tool determines the coefficient of performance (COP) and feasibility of ASHP. The sizing algorithm incorporates peak heat demand, unitary final energy demand, and seasonal heat demand across various detached house sizes. Annual local heating system operation time and key economic indicators are derived for each case across 3 European countries. A new approach is precise investigation of 10-year outdoor temperatures and apply it to heat pump (HP) modeling, which enabled a distinction between so-called warm and cold years. The results underscore substantial variations in net present value (NPV) between warm and cold years, illustrating the critical influence of precise climate data on the performance of HPs. The study revealed that for a 160 m2 house in Poland, annual electricity consumption by HPs ranged from 3736 kWh during warm years to 12,908 kWh during cold years, showing a significant variation in performance based on climate conditions. The comprehensive tool allows for precise adjustments of heating systems to actual local climate conditions, improving both economic and environmental outcomes. This comparative assessment aids in the optimal selection of HPs, ensuring energy efficiency and sustainability in residential heating systems. Building on studies from various climatic regions, this work addresses the knowledge gap in performance and explores the feasibility of HP in a changing climate using precise modeling techniques.

Design and experimental characterization of a propane-based reversible dual source/sink heat pump

The current paper presents the design and energy performance analysis of a propane-based reversible Dual Source/Sink Heat Pump (DSHP). DSHPs offer an alternative to conventional water to water and air to water heat pumps, leveraging the strengths of both technologies in an efficient manner. The developed prototype incorporates an innovative Dual Source/Sink Heat eXchanger (DSHX), enabling the unit operating in various modes, including space heating, space cooling, and domestic hot water production using brine, air or both simultaneously as a source/sink. The DSHX serves as as both a condenser or an evaporator, directly rejecting or absorbing heat from air and/or brine. By eliminating secondary loops and defrost cycles, the DSHX minimizes energy losses. The main novelty of this work lies in the DSHX that integrates external units typically duplicated in DSHPs into a single component, eliminating the need for split refrigerant flow rates, thus avoiding maldistribution, refrigerant charge increase and draining valves. A steady state experimental campaign was conducted in a climatic chamber to characterize the DSHP prototype and validate the DSHX performance models. Heating capacity up to 11.2 kW and COP values up to 4.7 were achieved at nominal compressor speed by supplying hot water at 35 °C with an ambient temperature of 7 °C. Similarly, when producing cold water at 7 °C, cooling capacity and EER reached 9.8 kW and 3.6, respectively, at nominal compressor speed using air as heat sink at 35 °C. The effects of various operating parameters on the overall coefficient of performance and heat duty in both heating and cooling modes, considering air or brine as heat source/sink are analyzed in detail. Results demonstrate enhancements of approximately 15 % in capacity and efficiency compared to earlier work. Moreover, four deterministic models were created in order to predict the behaviour of the DSHX and validated against experimental results, reaching deviation values below 15 %.

River water heat pumps to decarbonise district heating and promote the resilience of hydrosystems: Technico-economic, environmental and sociological challenges

The interdependence between water and energy (water-energy nexus) has been identified as one of the major challenges at European level, with roadmaps calling for the development of integrated approaches in this sector. The increase in river temperature is at the heart of this nexus, with anthropogenic thermal pollution adding to the effect of global warming. River Water Heat Pumps can play a major role by decarbonising district heating network (DHN) while actively cooling the aquatic resource. Hence, the objective of this short communication is to identify the scientific challenges to be met and the progress to be achieved considering the current state of the art. To illustrate the point, a rapid evaluation of the potential is performed for the city of Lyon in France resulting in an achievable cooling of ∼1.5 K which is above the minimum threshold to see an effect on aquatic ecosystem while the CO2 savings are significant for the DHN (∼ divided by a factor of 10). Because of its holistic nature, the impact assessment of such a system implies considering a wide diversity of indicators: energy, environmental, economics and sociological that need to be appropriately defined and quantified. In each field, progress beyond the state of the art to be performed has been identified, e.g. 4E analysis, cold water plume dispersion, integration of biodiversity in LCA.

Energy, economic and environmental analysis of a photovoltaic-thermal integrated dual-source heat pump system under a system coefficient of performance − based switching strategy

The photovoltaic-thermal integrated dual-source heat pump system can offer performance improvement by addressing the limitations of a single heat pump system, which not only improves energy efficiency and system performance but also reduces pollutant emissions. However, the operational performance of the system is significantly affected by different switching strategies between two heat sources, which has not been given adequate attention from researchers. Therefore, this study introduced a system coefficient of performance − based switching strategy, which can alternate between air-source heat pump and solar water heat pump modes to make full use of air and solar energy, to optimize the operation of the photovoltaic-thermal integrated dual-source heat pump system and compare with the conventional water temperature of the heat storage tank − based switching strategy. A TRNSYS model of the system was developed and validated, and the simulated results demonstrated the better performance of system coefficient of performance − based switching strategy in energy, economic and environmental perspectives. The average photoelectric and photothermal conversion efficiency under system coefficient of performance − based switching strategy were higher than those under water temperature of the heat storage tank − based switching strategy by 1.1 % and 4.0 %, respectively, with average modified coefficient of performance of 7.43 and 6.55. Furthermore, the system not only achieved savings of 5.63 % in annual electrical cost and 5.33 % in yearly operational cost but also reduced standard coal by 19.25 kg and total pollutant emissions by 242.55 kg per year under system coefficient of performance − based switching strategy, compared to water temperature of the heat storage tank − based switching strategy.

Leveraging Isoreticular Principle to Elucidate the Key Role of Inherent Hydrogen-Bonding Anchoring Sites in Enhancing Water Sorption Cyclability of Zr(IV) Metal-Organic Frameworks.

Water adsorption/desorption cyclability of porous materials is a prerequisite for diverse applications, including atmospheric water harvesting (AWH), humidity autocontrol (HAC), heat pumps and chillers, and hydrolytic catalysis. However, unambiguous molecular insights into the correlation between underlying building blocks and the cyclability are still highly elusive. In this work, by taking advantage of the well-established isoreticular synthetic principle in Zr(IV) metal-organic frameworks (Zr-MOFs), we show that the inherent density of hydrogen atoms in the organic skeleton can play a key role in regulating the water sorption cyclability of MOFs. The ease of isoreticular practice of Zr-MOFs enables the successful syntheses of two pairs of isostructural Zr-MOFs (NU-901 and NU-903, NU-950 and SJTU-9) from pyrene- or benzene-cored carboxylate linkers, which feature scu and sqc topological nets, respectively. NU-901 and NU-950 comprised of pyrene skeletons carrying more hydrogen-bonding anchoring sites show distinctly inferior cyclability as compared with NU-903 and SJTU-9 built of benzene units. Single-crystal X-ray crystallography analysis of the hydrated structure clearly unveils the water molecule-involved interactions with the hydrogen-bonding donors of benzene moieties. Remarkably, NU-903 and SJTU-9 isomers exhibit outstanding water vapor sorption capacities as well as working capacities at the desired humidity range with potential implementations covering indoor humidity control and water harvesting. Our findings uncover the importance of hydrogen-bonding anchoring site engineering of organic scaffold in manipulating the framework durability toward water sorption cycle and will also likely facilitate the rational design and development of highly robust porous materials.

Decarbonization of Heating and Cooling Systems of Buildings Located Nearby Surface Water Sources: Case Study

The study was carried out to evaluate theoretically and in laboratory conditions the capacity of a hybrid heating and cooling system that sustainably uses thermal energy extracted from surface waters in order to decarbonize buildings located near water sources. The novelty of the research consists in the realization of two experimental systems, one for the rapid evaluation of the performance of the water–water heat pump heating system and one for the evaluation of the operating behavior of a cooling system with fan coil units. Starting with the heating and cooling demand, and the climatic and hydrological local characteristics, a hybrid system model for the heating and cooling of the analyzed building was established and implemented. The forecasted energy consumption and CO2 emissions for the operation of the new equipment were compared with the historical values of the old systems with which the building was equipped (thermal energy supply from the district heating and cooling system with an air conditioning unit). Also, the results were extrapolated for forecasting the energy potential of the surface waters. The study highlights a percentage reduction in annual energy consumption of 67.71% and CO2 emissions of 80.13% through the implementation of the hybrid system.

Isoreticular Curves: A Theory of Capillary Condensation To Model Water Sorption within Microporous Sorbents.

Metal-organic frameworks have gained traction as leading materials for water sorption applications due to precise chemical tunability of their well-ordered pores. These applications include atmospheric water capture, heat pumps, desiccation, desalination, humidity control, and thermal batteries. However, the relationships between the framework pore structure and the measurable water sorption properties, namely critical relative humidity for condensation, maximal capacity, and pore size or temperature for the onset of hysteresis, have not been clearly delineated. Herein, we precisely formulate these relationships by application of the theory of capillary condensation and macroscopic thermodynamic models to a large data set of MOF water isotherms. These relationships include a concept termed isoreticular curves that relates the critical pressure for pore condensation (α), gravimetric capacity (Qmax), and hydrophilicity (the Gibbs free energy for binding water, ΔG) as Qmax = a1(ΔG/ln α)2 + a2(ΔG/ln α), with constants a1 and a2 dependent upon the density and volume occupied by the linker and secondary building unit, and framework topology. Through this analysis, we propose guidelines for the maximization of sorption capacity at a given relative humidity with minimal hysteresis and discuss the theoretical limits for capacity at low relative humidity. This model provides an explanation for the lack of high-capacity frameworks at low relative humidity, as increasing pore size also causes an increase in relative humidity. We propose a loose upper bound of Qmax = -0.25(1/ln α)2 - 1.75(1/ln α) for the limit of maximal capacity at a given relative humidity in the dry regime. These guidelines are consequential for the design of new materials for water sorption applications.

Exploring Urban Sustainability: The Role of Geology and Hydrogeology in Numerical Aquifer Modelling for Open-Loop Geothermal Energy Development, the Case of Torino (Italy)

This research examines the integration of geological and hydrogeological data in numerical aquifer model simulations, with a particular focus on the urban area of Torino, Italy. The role of groundwater resources in urban sustainability is analysed. The objective is to integrate open-loop geothermal plants into the district heating network of IREN S.p.A. Two case studies are examined: the Torino Nord area and the Moncalieri area, both of which host district heating plants. The work entails the collection and analysis of data from a variety of sources, including geognostic surveys and permeability tests, in order to construct a three-dimensional numerical model of the surface aquifer. Models were built using the public MODFLOW 6 (model of groundwater flow) code and calibrated using PESTHP (High Performance of Model Independent Parameter Estimation and Uncertainty Analysis). Results indicate the potential of urban aquifers as renewable energy sources and the necessity of comprehensive geological and hydrogeological assessments for optimal ground water heat pump (GWHP) system installation. This paper emphasises the significance of sustainable water management in the context of climate change and urbanisation challenges.

Multi-objective integrated optimization of geothermal heating system with energy storage using digital twin technology

Heat energy storage technology plays a significant role in energy systems, and the various technological solutions brought about by digitalization are especially valuable in the field of energy storage. This article proposes an innovative model based on digital twin technology to solve the supply–demand mismatch problem in geothermal heating systems. This model achieves multi-objective optimization of comprehensive cost, geothermal energy utilization rate, and carbon emission by constructing a heat storage geothermal heating system. Digital twin technology integrates data and information models of public buildings and facilitates their sharing and transmission throughout the entire lifecycle of the geothermal heating system. Initially, the proposed method employs a machine learning-based approach to accurately predict heating demand. Subsequently, the operation of the heat storage water tank and heat pump units is optimized to resolve difficulties in matching energy supply and demand. Finally, the method takes full advantage of time-of-use electricity pricing policies to reduce costs. The data utilized were collected from an office building in China over a period of six months. Experimental results demonstrate that: (1) In terms of predicting heating demand, the improved neural network proposed in this study achieved a prediction accuracy of 98%, which is a 10% improvement over comparative algorithms. Additionally, the experimental comparison of four types of errors showed that the machine learning method proposed had smaller errors across the board. (2) The method realized collaborative multi-objective optimization, and in five scenarios, the comprehensive performance index increased by up to 38.03% compared to the benchmark system. This indicates that intelligent technology is an effective means of enhancing the energy sustainability of geothermal heating systems, and the use of geothermal energy as a clean energy source effectively addresses issues related to the storage, utilization, management, and energy conservation of buildings.

Analysis of the Hybrid Power-Heating System in a Single-Family Building, along with Ecological Aspects of the Operation

This study evaluates a hybrid heating system in a single-family building in northeastern Poland, which has a temperate continental climate. The analysis covers two heating seasons in 2021/2022 and 2022/2023. The hybrid heating system includes an air heat pump HPA–08 CS Plus with a heating power of 8.2 kW (AHP), a condensing gas boiler VC146/5–5 with a power of 14 kW (GB–Condens.), and a solid fuel boiler with a power of 11 kW for central heating. Additionally, hot water is heated by a Basic 270 (DHW’s AHP) air–water heat pump with a power of 2 kW, utilizing a tank with a capacity of 270 dm3 equipped with two heating coils. The building’s average electricity consumption is around 5400 kWh/year. A 4.96 kWp photovoltaic installation is installed on the building’s roof at a 40° angle towards the south to supplement the hybrid system. The study aims to assess whether the PV installation can adequately cover the energy needs of the hybrid heat source for heating and hot water. Furthermore, the study calculates the emission of pollutants (CO2, SOx, NOx, CO, and PM10) into the atmosphere. The total annual electricity production from PV installations was 5444.9 kWh in 2021/2022 and 5684.8 kWh in 2022/2023. The excess electricity was stored in the PGE power grid as per the Prosumer settlement rules. The installed PV installation is sufficient to power the following devices annually: AHP, DHW’s AHP, and GB–Condens. However, the daily electricity production from the PV installation is not enough to cover the energy needs of the heat pump for heating during the cold months in Poland (I–III, XI–XII). It can meet the power needs of a PC all year round and can also be stored during the summer months, for example, in energy warehouses or by directly storing it in the PGE power grid. The use of the PV installation resulted in an average reduction in pollutant emissions into the atmosphere: CO2—94.1%, SOx—91.8%, NOx—95.6%, CO—9.7%, and PM10—32.1%.

Thermal response and performance evaluation of floor radiant heating system based on fuzzy logic control

The floor radiant heating system is widely used in various buildings due to its advantages such as high efficiency, comfort, and uniform heating. Generally, research on floor radiant heating systems focuses on energy saving, but the issue of slow thermal response during the heating process has not been solved. To solve the problem of slow thermal response and uneven indoor thermal environment in floor radiant heating systems, a fuzzy logic control theory based on optimal fuzzy rules was proposed. The floor radiant heating system based on fuzzy logic control was established by the TRNSYS-MATLAB integrated control platform. The study compared the thermal response and thermal comfort performance of PID control, fuzzy logic control, and optimized fuzzy control methods. The results showed that fuzzy logic control performed better than PID control in controlling the system's thermal performance and indoor thermal environment. Compared to PID control, the optimized fuzzy control reduced the thermal response time by 64.60%, and the total energy consumption of the water pump and heat pump decreased by 222 kWh and 329 kWh, respectively. The proposed fuzzy logic control demonstrates favorable thermal response characteristics and holds substantial potential for energy conservation within the increasingly prevalent floor radiant heating systems.

Experimental characterization and numerical modelling of an air to water CO2 heat pump under different outdoor and operating conditions for domestic hot water generation

This work assesses the influence of different outdoor and operating conditions on the performance of an air-to-water CO2 heat pump for domestic hot water (DHW) generation. For that purpose, an air to water CO2 heat pump with internal heat exchanger (IHX) was developed and characterized in an experimental campaign under well-controlled lab conditions. The system includes an in-house control system implemented to operate at the optimal gas cooler pressure. The heat pump and the control system are tested for DHW generation. The heat pump uses a finned-tubes heat exchanger as evaporator and plate heat exchangers as gas cooler and internal heat exchanger. The numerical model used a 1dimensional, cell by cell discretization method to characterize the performance of both, the gas-cooler and the evaporator under a wide range of values of their key variables. The IHX is also modelled with the same strategy. ARHI equations are considered to describe the compressor performance. The experimental data obtained are used to validate a numerical model of the heat pump under different air velocities, air temperatures and air humidity at the evaporator. The effectiveness of the control system proposed is experimentally confirmed during the experimental tests. Results show a good agreement between the numerical simulations and the experimental data what permits to validate the model and to assess the performance of the transcritical heat pump under different climate conditions.

The Effect of the Temperature Increase on Heat Demand Calculation for Building in the Polish Climatology

Heat demand calculation procedures for buildings are currently being conducted based on the Polish Standard grounded on the European Standard for heat losses methodology. Poland was divided into several climatic zones with given calculations and annual average external air temperature values. In each zone, the technical committee gives the temperature that must be considered. The data included in the Polish Standard preparation concern several years backwards. However, throughout the previous years, we have observed the tendency of the temperature to increase throughout the year, not only in Poland. The phenomenon provides scientists with the conclusion that the temperatures will continue to increase yearly. The low temperatures in the winter season will no longer occur. Therefore, it is necessary to analyse the possibility of lowering the heat demand calculation, including the actual prevailing temperature values. The study was conducted regarding possible economic benefits for the building users due to the lower temperature difference between the internal and external temperatures. Three types of heating systems were analysed. The calculations were conducted for air to water heat pump, pellet boiler and gas condensing boiler, proving that regarding the actual meteorological data, the average annual cost reduction will be in the range of 858 PLN to 1,035 PLN.

Optimal control of a heat pump-based energy system for space heating and hot water provision in buildings: Results from a field test

This paper presents and discusses results from a field test that uses model predictive control (MPC) to optimise the operation of a multi-source heat pump-based energy system for space heating and hot water provision in a building. The objective of the optimisation is to minimise the electricity consumption of the heat pump using flexibility from the heat sources, the space heating and domestic hot water tanks while ensuring end-user comfort and system constraints. The field test was performed in the context of the RES4BUILD project. The integrated system consists of photovoltaic-thermal (PVT) collectors, an advanced vapour-compression multi-source heat pump and water buffer tanks for space heating and hot water needs. The heat pump utilises a solar buffer, a borehole thermal energy storage (BTES) and air as heat sources. The solar buffer is supplied with heat from the PVT collectors. The optimal operation of the system is obtained by monitoring and controlling the interactions between the different system components using MPC, taking into account the weather and heat load forecasts. Results have shown that MPC has a potential and added value for the optimal operation of multi-source heat pumps in real-life while considering system constraints and user behaviour to ensure thermal comfort. However, significant effort and expert knowledge are needed to develop the sufficiently accurate system models required by this control approach. The outcomes and conclusions of this work are therefore a basis for further development of such control approaches to improve their replicability and feasibility on a large scale, considering the diverse nature of energy system components in buildings.

Analytical modelling and optimisation of a solar-driven cooling system enhanced with a photovoltaic evaporative chimney

Solar-driven heat pump systems can significantly reduce the energy use in buildings, thereby contributing to meet Europe’s climate commitments, including building decarbonisation by 2050. The research gap filled by this study is the development of an analytical model of a novel photovoltaic evaporative cooling chimney system previously described in the literature. The models for the system components were validated with experimental data, showing a maximum difference of 5.83%.An optimisation analysis based on the grid energy efficiency ratio as key performance indicator was conducted. The condenser water flow rate was identified as the key variable in this analysis. For a given design environmental and operating conditions, the optimal value for this magnitude was 1.05 m3 h−1, enabling a 3.8 kW load with only 44.33 W from the grid.The ambient temperature and relative humidity have the greatest influence on the overall system performance. They affect both, the panels’ efficiency and the chiller performance. Their combined influence could lead to a 10.86% reduction in the energy use while meeting the cooling load.The comparative study considering other solar cooling systems, assessed that the use of the solar chimney and the water–water heat pump enhances the overall performance of the main components of the system: 53% improvement for the chiller and 10% for the PV panels. Both effects combined, lead to an average grid energy efficiency ratio of 11.58.This study provides valuable insights for the design and implementation of efficient solar-driven cooling technologies, advancing beyond previous efforts in the literature.

Theoretical study for an air -water heat pump with low GWP refrigerant

Theoretical study for an air -water heat pump with low GWP refrigerant

Experimental investigation on a screw-type air source heat pump system with air heat absorption defrosting

Defrosting is crucial challenge for air-source heat pump operating in cold and humid climates due to its adverse impact on the heating efficiency. Conventional reverse cycle defrosting method has the disadvantages of reduced heating capacity, inefficient defrosting, and unstable heating temperatures. To address this issue, an Air Heat Absorption Defrosting method based on the reverse Carnot cycle principle was proposed to ensure uninterrupted heating during defrosting. To further validate the technical feasibility and energy-saving potential of the proposed system, a 710.0 kW screw-type air–water heat pump prototype was constructed to carry out control experiments under various conditions. Experimental results showed that, the proposed method achieved an average heating capacity of 315.7 kW during the defrosting process. The cyclic equivalent heating capacity and defrosting correction coefficient of the proposed method were 61.8 kW and 14.4 % higher in comparison with conventional reverse cycle defrosting method, respectively. Thus, the temperature fluctuation of supply water during the defrosting process was reduced by 69 %. In addition, the cumulative COP of Air Heat Absorption Defrosting method was 9.3 % higher than reverse cycle defrosting method, which could be attributed to the fact that the defrosting energy mainly came from air heat absorption. These findings highlight the potential of proposed Air Heat Absorption Defrosting method in addressing heat pump defrosting challenges while offering significant energy-saving benefits.

The optimization and energy efficiency analysis of a multi-tank solar-assisted air source heat pump water heating system

This article undertakes an optimization study of a solar-assisted air source heat pump water heating system by harnessing the advantages inherent in a multiple water tank arrangement. The Hooke-Jeeves algorithm was adopted to optimize the system parameters. The optimization variables encompass pivotal parameters such as water tank volume, collector area, dip angle, azimuth angle and heat pump power, while the objective function is the annual value of life cycle cost. By research and analysis of the monthly power consumption, electricity cost, solar fraction, average coefficient of performance (COP) and annual value of carbon emissions of the single-tank, dual-tank, and triple-tank system, it is discovered that the triple-tank system exhibits superior performance in overall aspects. Compared to the pre-optimized version, it achieves an annual energy consumption reduction of approximately 3.9%, leading to a 22.5% decrease in electricity expenses. Furthermore, it brings a 5.2% reduction in the annual lifecycle cost and a 6.3% decrease in carbon emissions, while simultaneously improving exergy efficiency by 4.8%.