Heat pumps are devices that transfer heat from a low-temperature source to a high-temperature one, using a refrigerant as the working fluid. They can be used for both heating and cooling applications, and are considered a clean and efficient alternative to fossil fuels. However, conventional heat pumps have limitations in operating in extreme conditions, such as very low or high ambient temperatures, which reduce their performance and reliability.
To overcome this challenge, Danfoss, a global leader in engineering solutions, has developed a new scroll compressor with vapor injection technology, called the PSH compressor. The PSH compressor is designed for medium and high temperature applications, such as commercial heat pumps, and can operate in a wider range of temperatures than standard scroll compressors. It can achieve condensing temperatures up to 65°C and evaporating temperatures down to -30°C, which makes it suitable for colder climates and extreme conditions.
The PSH compressor is also compatible with low-GWP (global warming potential) refrigerants, such as R454B, which have a lower environmental impact than conventional refrigerants, such as R410A. The PSH compressor is optimized for R454B, which has a GWP of 466, compared to 1924 for R410A. This means that the PSH compressor can help reduce greenhouse gas emissions and contribute to the decarbonization of the heating sector.
The PSH compressor has several features and benefits that make it a game-changer for heat pump adoption. Some of them are:
- Innovative vapor injection technology: The PSH compressor uses a liquid injection port and a vapor injection port to inject refrigerant into the compression chamber at different stages of the compression cycle. This increases the mass flow rate and the pressure ratio of the compressor, which improves its efficiency and capacity. The vapor injection also reduces the discharge temperature of the compressor, which extends its lifetime and prevents overheating.
- Simple and economical solution: The PSH compressor is easy to integrate into a heat pump system, as it requires only an additional ¼ inch pipe connection for the liquid injection. It does not need any additional components, such as valves, sensors, or controllers, which simplifies the system design and reduces the cost and complexity. The PSH compressor can also be used in tandem or trio configurations, with a single economizer heat exchanger, which offers greater flexibility and scalability for larger systems.
- High reliability and protection: The PSH compressor is equipped with an Operating Control System (OCS), which provides full compressor protection and higher system reliability. The OCS monitors the compressor parameters, such as pressure, temperature, current, and voltage, and adjusts the operation accordingly. The OCS also prevents the compressor from running outside its safe operating envelope, which reduces downtime and cuts system warranty costs.
The PSH compressor is a breakthrough innovation that can help make heat pumps more viable and attractive for heating applications in colder climates and extreme conditions. By increasing the operating range, efficiency, and reliability of heat pumps, the PSH compressor can help drive the market adoption of heat pumps and decrease the need to burn fossil fuels for heating. This can have significant benefits for the environment, the economy, and the society, as heat pumps can provide clean, renewable, and affordable energy for various sectors and applications.
