A startup company has developed an innovative thermoacoustic engine for a heat pump
BlueHeart Energy (BHE) is a technology start-up company that has developed a revolutionary thermoacoustic (TA) heat pump engine. This next-generation heat pump technology offers an alternative to the vapor compression method and aims to more fully meet the requirements of existing buildings, reports BUILD UP, the European portal for energy efficiency and renewable energy in buildings.
The challenges
Modern heat pump technology faces a number of challenges, mainly related to the EU ban on the use of synthetic refrigerants with a high greenhouse gas warming potential (GWP), noise levels of heat pumps and restrictions on heating existing buildings with medium to high temperatures. submission. Propane heat pumps (R290) are a solution for the industry, but they are associated with limitations and/or costs due to the flammability of propane, while they cannot fully cover noise level requirements and solve temperature problems.
The thermoacoustic heat pump engine developed by BHE addresses the above challenges thanks to several significant advantages and offers a suitable solution for heating, cooling and hot water supply of smaller compact houses, explain the company's experts and present details of the device.
Advantages of thermoacoustic technology
Operating principle
The TA engine is an electric heat pump system designed for modulating output capacity from 1 kW to 6 kW and has the following dimensions: length 58 cm and diameter 45 cm.
领英推荐
The system consists of a hermetically sealed cylindrical vessel filled with helium gas, with a pressure of 50 to 60 bar, two linearly moving pistons located opposite each other, driven by two electric actuators. The pistons create an acoustic wave (pressure) with a maximum amplitude of approximately 4 bar at a frequency of approximately 60 Hz. The reciprocating mechanism creates the acoustic power of the TA engine, which ensures the operation of the heat pump.
The acoustic pressure wave is transmitted in a specially designed closed loop in which a TA core is mounted. It includes two heat exchangers, a regenerator and an optional membrane barrier. One heat exchanger (the hot one) is connected to the heating system of the house, and the other heat exchanger (the cold one) – to the heat pump inlet. The regenerator is placed between these heat exchangers.
Key aspects
The system uses helium gas only as the working medium, there is no evaporation or condensation. Industrial TA systems can provide temperatures up to 180°C. The BHE system is designed to operate in a range between 80°C supply temperature and about -20°C cold air. Helium is a non-flammable and non-toxic gas and this allows a TA system to be very flexible in terms of source types and temperature differences.
The drive mechanism is designed with linearly moving pistons located on one axis, which mutually compensate for their vibrations. Thus, the noise during operation of the system is not loud and is below 35 dB(A). The pistons are the only moving parts and have pneumatic bearings, which contributes to low wear and a long life of 20 years of the facility.
Stage of development and market prospects
The first prototype of the product has already been fully tested and is working. It is a TA engine placed in a pressure vessel 58 cm long and 45 cm in diameter, allowing easy disassembly and replacement of components. In 2023, over 20 different configurations were tested with various combinations of piston-cylinder types, heat exchangers, internal membrane and regenerators.
With the second version of the model, the BHE engine is integrated into a complete heat pump system, including the circulation pumps and the control of a 6 kW heat pump, replacing the evaporator, condenser and compressor. The system is expected to be put into operation in the near future.