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Your search keyword '"Hinokuma, Ryohei"' showing total 3 results
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3 results on '"Hinokuma, Ryohei"'

1. Next-Generation Residential Space Conditioning System for California.

Author

Beaini, Sara, Amarnath, Ammi, Hunt, Walter, Domitrovic, Ronald, Krishnamoorty, Sreenidhi, Harrington, Curtis, Modera, Mark, Davis, Robert, Hinokuma, Ryohei, and Blatt, Morton

Subjects
*VARIABLE speed drives, *HEATING & ventilation industry equipment, *HEAT pumps, *TECHNOLOGY assessment, *PERFORMANCE technology, *NATURAL gas, *EVALUATION methodology
Abstract

The Next Generation Residential Space Conditioning System for Calif ornia (Next Gen RSCS) is an integration of multiple advanced HVAC technologies including: a variable capacity compressor, variable speed blower fan, automated demand response, fault detection and diagnostics, intelligent dual fuel heating (gas/electric), integrated ventilation, and zonal control. In addition to these f eatures, an alternative ref rigerant, (R-32), was evaluated as a possible future enhancement. Along with these technology evaluations, an assessment was performed on duct losses for single versus multi-zone duct conf igurations with variable capacity equipment. The experimental results, f rom 3 leading U.S. laboratories, provide information to the industry on optimizing the system for efficiency, utility integration, and homeowner comfort. Key findings from the laboratory evaluation of the Next Gen RSCS included: - Cooling energy savings range between 22-32% for Calif ornia (CA) compared to a 14 SEER single speed baseline system. - The system satisfies over 90% of annual heating load for most of CA without electrical or natural gas back-up. - Demand response capability with variable capacity equipment enables utilities to reduce peak demand while reducing customer discomfort. - Revising ducting standards and providing more efficient control strategies would improve the integration of heat pumps connected to attic ductwork for hot and dry Calif ornia climates. - Zonal control, integrated ventilation and intelligent heating deployed with the Next Gen RSCS offer energy cost savings and system versatility. - Heating and cooling mode experimental results of the Next Gen RSCS with R-32 as a drop-in ref rigerant demonstrated comparable or improved performance to R-410A. The Next Gen RSCS is under f ield evaluation in 3 homes in the CA Investor Owned Utility (IOU) service territories (PG&E, SCE, and SDG&E). The presentation will include an assessment of the technologies' performance studied in the laboratory and associated modeling, as well as the status of the f ield evaluation and the methodology employed. [ABSTRACT FROM AUTHOR]

Published
2019

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

Author

Zhang, Rongpeng, Sun, Kaiyu, Hong, Tianzhen, Yura, Yoshinori, and Hinokuma, Ryohei

Subjects
*REFRIGERANTS, *HEAT recovery, *VENTILATION, *BUILDING performance
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. This can further 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 essential 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 shows 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. [ABSTRACT FROM AUTHOR]

Published
2018
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3. Development and validation of a new variable refrigerant flow system model in EnergyPlus.

Author

Hong, Tianzhen, Sun, Kaiyu, Zhang, Rongpeng, Hinokuma, Ryohei, Kasahara, Shinichi, and Yura, Yoshinori

Subjects
*ENERGY consumption of buildings, *REFRIGERANTS, *THERMAL comfort, *HEAT pumps, *COMPUTER simulation, *ENERGY conservation in buildings
Abstract

Variable refrigerant flow (VRF) systems vary the refrigerant flow to meet the dynamic zone thermal loads, leading to more efficient operations than other system types. This paper introduces a new model that simulates the energy performance of VRF systems in the heat pump (HP) operation mode. Compared with the current VRF-HP models implemented in EnergyPlus, the new VRF system model has more component models based on physics and thus has significant innovations in: (1) enabling advanced controls, including variable evaporating and condensing temperatures in the indoor and outdoor units, and variable fan speeds based on the temperature and zone load in the indoor units, (2) adding a detailed refrigerant pipe heat loss calculation using refrigerant flow rate, operational conditions, pipe length, and pipe insulation materials, (3) improving accuracy of simulation especially in partial load conditions, and (4) improving the usability of the model by significantly reducing the number of user input performance curves. The VRF-HP model is implemented in EnergyPlus and validated with measured data from field tests. Results show that the new VRF-HP model provides more accurate estimate of the VRF-HP system performance, which is key to determining code compliance credits as well as utilities incentive for VRF technologies. [ABSTRACT FROM AUTHOR]

Published
2016
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