The reason why solar-driven lithium bromide absorption chillers are often paired with a hot oil system lies in the characteristics of solar energy and the strict requirements of absorption-based cooling technologies for stable heat input. Solar energy is inherently intermittent and fluctuates significantly with weather, diurnal cycles, and seasonal changes, resulting in an unstable heat output. If such fluctuating heat were supplied directly to a lithium bromide absorption chiller, it could cause cooling capacity variations and even affect the long-term reliable operation of the equipment. Therefore, in practical engineering applications, an intermediate medium is needed to “balance” and regulate the heat, and hot oil serves precisely this role.

From a technical perspective, both lithium bromide absorption chillers and absorption heat pumps operate by using heat as the driving force and require medium- to high-temperature heat sources for efficient operation. Using water as the heat transfer medium would typically require high-pressure conditions to reach the necessary temperatures, making the system complex and posing safety risks. In contrast, hot oil can stably transfer high temperatures at atmospheric pressure, reducing system risks and improving operational reliability. This is why, in Hope Deepblue’s solar cooling and waste heat utilization projects, hot oil serves as the key medium connecting the solar collector system with the lithium bromide absorption chillers and absorption heat pumps.

During system operation, solar collectors first convert sunlight into thermal energy, which is stored in the hot oil. The hot oil then delivers heat evenly and continuously to the lithium bromide absorption chiller or absorption heat pump. Even when solar irradiance fluctuates briefly, the hot oil system acts as a buffer, ensuring that the heat entering the equipment remains stable. This stable heat input helps maintain optimal operating conditions, extends equipment lifespan, and improves overall system performance.

Moreover, the hot oil system provides a strong foundation for multi-source heat integration. In practice, solar energy is often combined with industrial waste heat or auxiliary gas-fired heat sources. Through the hot oil loop, these diverse heat sources can be coordinated, and when solar irradiance is insufficient, other heat sources automatically supplement the system, ensuring continuous and reliable operation of the lithium bromide absorption chiller and absorption heat pump. Hope Deepblue leverages this systematic design to integrate clean energy with high-efficiency heat utilization, enabling solar-driven cooling and heating to move beyond theory into practical, scalable applications.

Overall, hot oil is far more than a simple heat transfer medium; it is a critical component in solar lithium bromide absorption chiller systems. It stabilizes fluctuating solar energy, allows lithium bromide absorption chillers and absorption heat pumps to operate efficiently and reliably, and maximizes the practical value of clean energy in industrial and building applications.