Air source heat pump for domestic hot water supply: Performance comparison between individual and building scale installations

Guo, Xiao‐Feng; Goumba, Alain

doi:10.1016/j.energy.2018.09.065

Cited by 50 publications

(14 citation statements)

References 9 publications

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“…(Zimmermann et al 2012;Brunschwiler et al 2009). In fact, the liquid-based cooling enables to harvest the waste heat at levels of 50 to 60°C that are already common for nowadays district heating applications (Lund et al 2018;Guo and Goumba 2018).…”

Section: Introductionmentioning

confidence: 99%

Simulation-based assessment of data center waste heat utilization using aquifer thermal energy storage of a university campus

et al. 2020

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The global energy consumption of data centers (DCs) has experienced exponential growth over the last decade, that is expected to continue in the near future. Reasonable utilization of DC waste heat, which is dissipated during the computational process, can potentially be an effective solution to mitigate the environmental impact. However, the practical implementation of waste heat utilization in the DC environment is a very challenging task. The possible benefits of waste heat utilization are uncertain and difficult to quantify with the methods that are common in practice. This paper introduces a feasibility study in which dynamic simulation tools were used to predict the energy performance of a university campus resulting from the integration of a proposed DC system with an existing aquifer thermal energy storage (ATES). The presented study utilizes building energy simulation (BES) to evaluate uncertainty of the waste heat potential associated to various thermal management strategies of the proposed DC. Further in the feasibility study, the carbon footprint of the integrated approach is assessed for both the current and future situation based on measured data from the existing university campus and its district ATES system.

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Section: Introductionmentioning

confidence: 99%

Simulation-based assessment of data center waste heat utilization using aquifer thermal energy storage of a university campus

et al. 2020

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“…In the WHR exchanger, the water in ambient temperature is heated to 338.15 K for the domestic hot water, 25 and the exhaust gas is finally discharged into the environment with a temperature of 25 K higher than the dew point to prevent condensation 22 . The heating capacity of the system is calculated by:

Q_{heat} = m_{EG} ((), h_{normalA 18} - h_{normalA 19}) .

…”

Section: Mathematical Modelmentioning

confidence: 99%

Conceptual design and performance analysis of a novelCHPsystem integrated with solid oxide fuel cell and supercriticalCO₂partial preheating cycle

et al. 2020

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Summary The paper proposes a novel combined heating and power (CHP) system integrated with solid oxide fuel cell (SOFC) and supercritical CO2 (SCO2) partial preheating cycle to improve the energy utilization rate by employing the SCO2 cycle to recover the waste heat from the SOFC. The SCO2 partial preheating cycle can not only improve the net output power but also preheat the air supplied to the SOFC for enhancing the system efficiency. Sensitivity analysis is implemented to study the influences of six key parameters (ie, fuel flow rate, excess air ratio, fuel utilization factor, CO2 turbine inlet temperature, CO2 compressor pressure ratio, and CO2 split ratio) on the proposed system in terms of thermodynamic behaviors. And then the optimal operating conditions for the different objectives are determined by parametric optimization. The results indicate that the optimal overall electrical efficiency and CHP efficiency of the proposed system are 72.84% and 83.83% respectively, while the exergy efficiency can achieve 70.84%. Furthermore, the best trade‐off result is obtained with the energy output of 434.71 kW and the exergy efficiency of 64.28%. Finally, the investigation demonstrates the fuel flow rate is the most sensitive parameter which should be determined with the comprehensive consideration of the efficiency and energy output, and the lower excess air ratio and higher CO2 turbine inlet temperature are preferred for power generation.

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“…Then, the duration curve was defined by adding the profiles for each type of building connected to the DHC network. Even if the local DHW usage presents typical patterns with peaks in the morning and the evening according to the different building destinations [51,52], the total daily DHW energy consumption for the entire urban area gets fairly constant throughout the year [4]. Small differences typically occur during summer in relation to holiday periods.…”

Section: Network Annual Energy Consumptionmentioning

confidence: 99%

Double Loop Network for Combined Heating and Cooling in Low Heat Density Areas

et al. 2020

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This study investigated a double loop network operated with ultra-low supply/return temperatures of 45/25 °C as a novel solution for low heat-density areas in Denmark and compared the proposed concept with a typical tree network and with individual heat pumps to each end-users rather than district networks. It is a pump-driven system, where the separate circulation of supply and return flow increased the flexibility of the system to integrate and displace heating and cooling energy along the network. Despite the increased use of central and local water pumps to operate and control the system, the simulated overall pump energy consumption was 0.9% of the total energy consumption. This was also an advantage at the design stage as the larger pressure gradient, up to 570 Pa/m, allowed minimal pipe diameters. In addition, the authors proposed the installation of electrically heated vacuum-insulated micro tanks of 10 L on the primary side of each building substation as a supplementary heating solution to meet the comfort and hygiene requirements for domestic hot water (DHW). This, combined with supply water circulation in the loop network, served as a technical solution to remove the need for bypass valves during summer periods with no load in the network. The proposed double loop system reduced distribution heat losses from 19% to 12% of the total energy consumption and decreased average return temperatures from 33 °C to 23 °C compared to the tree network. While excess heat recovery can be limited due to hydraulic issues in tree networks, the study investigated the double loop concept for scenarios with heat source temperatures of 30 °C and 45 °C. The double loop network was cost-competitive when considering the required capital and operating costs. Furthermore, district networks outperformed individual heat pump solutions for low-heat density areas when waste heat was available locally. Finally, although few in Denmark envisage residential cooling as a priority, this study investigated the potential of embedding heating and cooling in the same infrastructure. It found that the return line could deliver cold water to the end-users and that the maximum cooling power was 1.4 kW to each end-user, which corresponded to 47% of the total peak heat demand used to dimension the double loop network.

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Air source heat pump for domestic hot water supply: Performance comparison between individual and building scale installations

Cited by 50 publications

References 9 publications

Simulation-based assessment of data center waste heat utilization using aquifer thermal energy storage of a university campus

Simulation-based assessment of data center waste heat utilization using aquifer thermal energy storage of a university campus

Conceptual design and performance analysis of a novelCHPsystem integrated with solid oxide fuel cell and supercriticalCO₂partial preheating cycle

Double Loop Network for Combined Heating and Cooling in Low Heat Density Areas

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Air source heat pump for domestic hot water supply: Performance comparison between individual and building scale installations

Cited by 50 publications

References 9 publications

Simulation-based assessment of data center waste heat utilization using aquifer thermal energy storage of a university campus

Simulation-based assessment of data center waste heat utilization using aquifer thermal energy storage of a university campus

Conceptual design and performance analysis of a novelCHPsystem integrated with solid oxide fuel cell and supercriticalCO2partial preheating cycle

Double Loop Network for Combined Heating and Cooling in Low Heat Density Areas

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Product

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Conceptual design and performance analysis of a novelCHPsystem integrated with solid oxide fuel cell and supercriticalCO₂partial preheating cycle