This paper reports the results of an experimental and numerical study of different configurations of a CO₂ water-to-water heat pump for hot water generation. The experimental installation developed to test the heat pump unit is briefly described and then the experimental results are presented. Numerical results of a model previously developed are compared with experimental results, allowing the validation of the model. Once the model is validated, it is used to predict untested conditions. The results show, for several hot water generation scenarios, the influence that different parameters have on the system performance, including the gas cooler pressure, the internal heat exchanger (IHX) effectiveness, and the heat exchangers area on the efficiency of the system. For low and intermediate heating temperatures, the optimal gas cooler pressure is nearly independent of the range of evaporation water temperature (5 to 30°C), therefore a constant pressure control able to maintain the pressure slightly above the optimal value, can be the best solution. On the other hand, for medium, and high temperatures, an adaptive control system is strongly recommended. Although the influence of a variation in the heat exchangers area depends on the operating conditions, in general terms, the area of the gas cooler has the higher influence on the efficiency of the system and the area of the IHX has the smaller influence. As the gas cooler temperature increases or the evaporation temperature decreases, the improvement obtained by increasing the HXs area decreases.

本文报告了不同配置的 CO ₂的实验和数值研究结果。用于产生热水的水对水热泵。简要描述了为测试热泵机组而开发的实验装置，然后给出了实验结果。将先前开发的模型的数值结果与实验结果进行比较，从而对模型进行验证。一旦模型得到验证，它就被用来预测未经测试的条件。结果表明，对于几种热水生成场景，不同参数对系统性能的影响，包括气体冷却器压力、内部换热器 (IHX) 效率以及换热器面积对系统效率的影响。对于中低加热温度，最佳气体冷却器压力几乎与蒸发水温范围（5 至 30°C）无关，因此，能够将压力保持在略高于最佳值的恒压控制可能是最佳解决方案。另一方面，对于中高温，强烈建议使用自适应控制系统。虽然换热器面积变化的影响取决于运行条件，但一般而言，气体冷却器的面积对系统效率的影响较大，而 IHX 的面积影响较小。随着气体冷却器温度升高或蒸发温度降低，通过增加 HXs 面积获得的改进减小。虽然换热器面积变化的影响取决于运行条件，但一般而言，气体冷却器的面积对系统效率的影响较大，而 IHX 的面积影响较小。随着气体冷却器温度升高或蒸发温度降低，通过增加 HXs 面积获得的改进减小。虽然换热器面积变化的影响取决于运行条件，但一般而言，气体冷却器的面积对系统效率的影响较大，而 IHX 的面积影响较小。随着气体冷却器温度升高或蒸发温度降低，通过增加 HXs 面积获得的改进减小。