利用淺層溫能之雙效熱泵性能之研究與設計

Abstract

本研究主要針對淺層溫能之利用與地源雙效熱泵之設計與開發，設計與開發符合淺層溫能該條件使用環境的雙效之熱泵，淺層溫能是指地下較淺處的地熱能源，通常溫度穩定不易改變之特性。因此，我們需要開發新型的熱泵系統，能夠高效利用這一淺層溫能，為建築供暖、供冷和熱水供應提供可靠的解決方案。 本研究熱泵相較傳統熱泵不同之處為新增一針對淺層溫能使用之熱交換器於熱泵之中，可以經由切換冷媒來達到不同模式控制之目的，並藉由間接熱交換與直接熱交換兩種方式來進行取熱與散熱並相互比較其效能，再由實際測試改善熱泵設計，進而發展出較穩定之機種。由研究結果顯示，第一代淺層地下溫能之雙效熱泵的問題主要在於切換模式時冷媒分布不均，研究提出了改善方案，並新增了自動控制電磁閥，提升了使用者便利性。第一代淺層地下溫能之雙效熱泵，在製冷模式下，間接散熱製冷COP為5.64，直接散熱製冷COP為6，在製熱模式下，間接取熱COP為3.7，直接取熱製熱COP為4.47。第二代熱泵改善後性能進一步提升，在製冷模式下，直接散熱製冷COP達到6.63。在製熱的模式下，直接取熱製熱COP達到4.81。 第二代淺層地下溫能之雙效熱泵在製冷和製熱模式下都有更高的性能表現，並且改進了切換模式時的問題，使得熱泵系統更加高效、穩定和方便使用。

This research focuses on the utilization of shallow geothermal energy and the design and development of a ground source heat pump (GSHP) that is suitable for shallow geothermal environments. Shallow geothermal energy refers to the geothermal energy source found at relatively shallow depths underground, known for its stable temperature characteristics. Therefore, a novel heat pump system needs to be developed to efficiently harness this shallow geothermal energy and provide a reliable solution for building heating, cooling, and hot water supply. In this study, a new heat pump system is developed, which includes a heat exchanger specifically designed for utilizing shallow geothermal energy. Different operating modes can be achieved by switching the refrigerant, and the performance of the system is compared between indirect heat exchange and direct heat exchange methods for heating and cooling. Based on practical testing and analysis, the heat pump design is improved to develop a more stable and efficient system. The first-generation shallow geothermal heat pump encountered issues related to uneven refrigerant distribution during mode switching. To address this problem, a solution is proposed, which includes the addition of automatic control electromagnetic valves to enhance user convenience. The first-generation shallow geothermal heat pump achieved a coefficient of performance (COP) of 5.64 for indirect heat exchange cooling, and a COP of 6 for direct heat exchange cooling. In heating mode, it obtained a COP of 3.7 for indirect heat exchange, and a COP of 4.47 for direct heat exchange. With the improvements made in the second-generation heat pump, the COP further increased, reaching 6.63 for direct heat exchange cooling and 4.81 for direct heat exchange heating. The second-generation shallow geothermal heat pump demonstrates higher performance in both cooling and heating modes. Additionally, the issues related to mode switching have been addressed, resulting in a more efficient, stable, and user-friendly heat pump system.