本文提出了一个新的模型来模拟变制冷剂流量（VRF）系统在热泵运行模式下的能量性能（可以提供冷却或加热，但不能同时提供）。室外机的主要功能是引入室内温度调节器和室外温度调节器。EnergyPlus中现有VRF模型的容量修正函数中的自变量主要是制冷模式和室内干燥模式下的室内湿球温度和室外干球温度- 加热模式下的灯泡温度和室外湿球温度。新方法允许符合每个室内机的不同规格，从而提高建模精度。新的VRF模型在EnergyPlus 7.2的定制版本中实现。本文首先描述了新VRF模型的算法，然后将其用于模拟加利福尼亚州原型住宅中VRF系统的能量性能，该原型住宅符合第24篇《加利福尼亚州建筑能效标准》的要求。然后将VRF系统性能与其他三种类型的HVAC系统进行比较: 标题24-2005基线系统、传统高效系统和三种典型加州气候下的EnergyStar热泵系统:桑尼维尔、帕萨迪纳和弗雷斯诺。计算得出的VRF系统节能效果显著。暖通空调现场节能范围为51%至85%，而TDV（时间相关估值）节能范围为31%至66%，与三种气候下的24个基准系统相比。节约能源最多的是弗雷斯诺气候，其次是桑尼维尔和帕萨迪纳。本文讨论了有助于节能的VRF系统的各种特性。 应注意的是，这些节省是在标准操作条件下使用第24号房屋原型D进行计算的。在实际操作条件下，用于实际房屋的VRF系统的实际性能会有所不同。引文:ASHRAE论文CD:2014 ASHRAE年会，华盛顿州西雅图

This paper presents a new model to simulate energy performance of variable refrigerant flow (VRF) systems in heat pump operation mode (either cooling or heating is provided but not simultaneously). The main improvement of the new model is the introduction of the evaporating and condensing temperature in the indoor and outdoor unit capacity modifier functions. The independent variables in the capacity modifier functions of the existing VRF model in EnergyPlus are mainly room wet-bulb temperature and outdoor dry-bulb temperature in cooling mode and room dry-bulb temperature and outdoor wet-bulb temperature in heating mode. The new approach allows compliance with different specifications of each indoor unit so that the modeling accuracy is improved. The new VRF model was implemented in a custom version of EnergyPlus 7.2. This paper first describes the algorithm for the new VRF model, which is then used to simulate the energy performance of a VRF system in a Prototype House in California that complies with the requirements of Title 24 - the California Building Energy Efficiency Standards. The VRF system performance is then compared with three other types of HVAC systems: the Title 24-2005 Baseline system, the traditional High Efficiency system, and the EnergyStar Heat Pump system in three typical California climates: Sunnyvale, Pasadena and Fresno. Calculated energy savings from the VRF systems are significant. The HVAC site energy savings range from 51 to 85%, while the TDV (Time Dependent Valuation) energy savings range from 31 to 66% compared to the Title 24 Baseline Systems across the three climates. The largest energy savings are in Fresno climate followed by Sunnyvale and Pasadena. The paper discusses various characteristics of the VRF systems contributing to the energy savings. It should be noted that these savings are calculated using the Title 24 prototype House D under standard operating conditions. Actual performance of the VRF systems for real houses under real operating conditions will vary.