Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser

Shen, Bo; Nawaz, Kashif; Baxter, Van D.; Elatar, Ahmed F.

doi:10.1016/j.ijrefrig.2017.10.023

Title: Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser

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Abstract

Heat pump water heater systems (HPWH) introduce new challenges for design and modeling tools, because they require vapor compression system balanced with a water storage tank. In addition, a wrapped-tank condenser coil has strong coupling with a stratified water tank, which leads HPWH simulation to a transient process. To tackle these challenges and deliver an effective, hardware-based HPWH equipment design tool, a quasi-steady-state HPWH model was developed based on the DOE/ORNL Heat Pump Design Model (HPDM). Two new component models were added via this study. One is a one-dimensional stratified water tank model, an improvement to the open-source EnergyPlus water tank model, by introducing a calibration factor to account for bulk mixing effect due to water draws, circulations, etc. The other is a wrapped-tank condenser coil model, using a segment-to-segment modeling approach. In conclusion, the HPWH system model was validated against available experimental data. After that, the model was used for parametric simulations to determine the effects of various design factors.

Authors:

Shen, Bo ^[1]; Nawaz, Kashif ^[1]; Baxter, Van D. ^[1]; Elatar, Ahmed F. ^[1]

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center

Publication Date:: 2017-10-31

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office

OSTI Identifier:: 1423094

Alternate Identifier(s):: OSTI ID: 1582926

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: International Journal of Refrigeration

Additional Journal Information:: Journal Volume: 87; Journal ID: ISSN 0140-7007

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 42 ENGINEERING; Heat pump water heater; Wrap-tank condenser coil; Modeling; Stratified water tank; Energy factor

Citation Formats


                    Shen, Bo, Nawaz, Kashif, Baxter, Van D., and Elatar, Ahmed F. Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser.  United States: N. p., 2017. 
Web.  doi:10.1016/j.ijrefrig.2017.10.023.

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                    Shen, Bo, Nawaz, Kashif, Baxter, Van D., & Elatar, Ahmed F. Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser.  United States.  https://doi.org/10.1016/j.ijrefrig.2017.10.023

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                    Shen, Bo, Nawaz, Kashif, Baxter, Van D., and Elatar, Ahmed F. Tue .  
"Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser".  United States.  https://doi.org/10.1016/j.ijrefrig.2017.10.023.  https://www.osti.gov/servlets/purl/1423094.

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@article{osti_1423094,

  title        = {Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser},

  author       = {Shen, Bo and Nawaz, Kashif and Baxter, Van D. and Elatar, Ahmed F.},

  abstractNote = {Heat pump water heater systems (HPWH) introduce new challenges for design and modeling tools, because they require vapor compression system balanced with a water storage tank. In addition, a wrapped-tank condenser coil has strong coupling with a stratified water tank, which leads HPWH simulation to a transient process. To tackle these challenges and deliver an effective, hardware-based HPWH equipment design tool, a quasi-steady-state HPWH model was developed based on the DOE/ORNL Heat Pump Design Model (HPDM). Two new component models were added via this study. One is a one-dimensional stratified water tank model, an improvement to the open-source EnergyPlus water tank model, by introducing a calibration factor to account for bulk mixing effect due to water draws, circulations, etc. The other is a wrapped-tank condenser coil model, using a segment-to-segment modeling approach. In conclusion, the HPWH system model was validated against available experimental data. After that, the model was used for parametric simulations to determine the effects of various design factors.},

  doi          = {10.1016/j.ijrefrig.2017.10.023},

  journal      = {International Journal of Refrigeration},

  number       = ,

  volume       = 87,

  place        = {United States},

  year         = {2017},

  month        = {10}

}

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