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Title: A novel Variable Refrigerant Flow (VRF) heat recovery system model: Development and validation

Abstract

As one of the latest emerging HVAC technologies, the Variable Refrigerant Flow (VRF) system with heat recovery (HR) configurations has obtained extensive attention from both the academia and industry. Compared with the conventional VRF systems with heat pump (HP) configurations, VRF-HR is capable of recovering heat from cooling zones to heating zones and providing simultaneous cooling and heating operations. Moreover, this could lead to substantial energy saving potential and more flexible zonal control. In this paper, a novel model is developed to simulate the energy performance of VRF-HR systems. It adheres to a more physics-based development with the ability to simulate the refrigerant loop performance and consider the dynamics of more operational parameters, which is crucial for representing more advanced control logics. Another key feature of the model is the introduction of component-level curves for indoor units and outdoor units instead of overall performance curves for the entire system, and thus it requires much fewer user-specified performance curves as model inputs. The validation study reflects good agreements between the simulated energy use from the new VRF-HR model and the laboratory measurement data across all operational modes at sub-hourly time steps. The model has been adopted in the official release ofmore » the EnergyPlus simulation program since Version 8.6, which enables more accurate and robust assessments of VRF-HR systems to support their applications in energy retrofit of existing buildings or design of zero-net-energy buildings.« less

Authors:
 [1];  [1];  [1];  [2];  [3]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Daikin Industries LTD, Osaka (Japan)
  3. Daikin US Corporation, New York, NY (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC); USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1532320
Alternate Identifier(s):
OSTI ID: 1496313
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Energy and Buildings
Additional Journal Information:
Journal Volume: 168; Journal Issue: C; Journal ID: ISSN 0378-7788
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; Variable Refrigerant Flow; Heat recovery; Energy modeling; Validation; Building performance simulation; Controls

Citation Formats

Zhang, Rongpeng, Sun, Kaiyu, Hong, Tianzhen, Yura, Yoshinori, and Hinokuma, Ryohei. A novel Variable Refrigerant Flow (VRF) heat recovery system model: Development and validation. United States: N. p., 2018. Web. doi:10.1016/j.enbuild.2018.03.028.
Zhang, Rongpeng, Sun, Kaiyu, Hong, Tianzhen, Yura, Yoshinori, & Hinokuma, Ryohei. A novel Variable Refrigerant Flow (VRF) heat recovery system model: Development and validation. United States. doi:10.1016/j.enbuild.2018.03.028.
Zhang, Rongpeng, Sun, Kaiyu, Hong, Tianzhen, Yura, Yoshinori, and Hinokuma, Ryohei. Tue . "A novel Variable Refrigerant Flow (VRF) heat recovery system model: Development and validation". United States. doi:10.1016/j.enbuild.2018.03.028. https://www.osti.gov/servlets/purl/1532320.
@article{osti_1532320,
title = {A novel Variable Refrigerant Flow (VRF) heat recovery system model: Development and validation},
author = {Zhang, Rongpeng and Sun, Kaiyu and Hong, Tianzhen and Yura, Yoshinori and Hinokuma, Ryohei},
abstractNote = {As one of the latest emerging HVAC technologies, the Variable Refrigerant Flow (VRF) system with heat recovery (HR) configurations has obtained extensive attention from both the academia and industry. Compared with the conventional VRF systems with heat pump (HP) configurations, VRF-HR is capable of recovering heat from cooling zones to heating zones and providing simultaneous cooling and heating operations. Moreover, this could lead to substantial energy saving potential and more flexible zonal control. In this paper, a novel model is developed to simulate the energy performance of VRF-HR systems. It adheres to a more physics-based development with the ability to simulate the refrigerant loop performance and consider the dynamics of more operational parameters, which is crucial for representing more advanced control logics. Another key feature of the model is the introduction of component-level curves for indoor units and outdoor units instead of overall performance curves for the entire system, and thus it requires much fewer user-specified performance curves as model inputs. The validation study reflects good agreements between the simulated energy use from the new VRF-HR model and the laboratory measurement data across all operational modes at sub-hourly time steps. The model has been adopted in the official release of the EnergyPlus simulation program since Version 8.6, which enables more accurate and robust assessments of VRF-HR systems to support their applications in energy retrofit of existing buildings or design of zero-net-energy buildings.},
doi = {10.1016/j.enbuild.2018.03.028},
journal = {Energy and Buildings},
issn = {0378-7788},
number = C,
volume = 168,
place = {United States},
year = {2018},
month = {3}
}

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Cited by: 5 works
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Figures / Tables:

Figure 1 Figure 1: Schematic chart of a 3-pipe VRF-HR system

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