A.V.Luikov Heat and Mass Transfer Institute of the NAS of Belarus offers consumers a heat exchangers on heat pipes and thermosyphons for air conditioning systems under a manufacturing agreement and is looking for partners interested in a distribution services agreement.

The key technology for the production of thermal energy, which is replacing the direct combustion of hydrocarbon fuels, are heat pump technologies and innovative systems for ensuring an optimal indoor microclimate.

A.V.Luikov Heat and Mass Transfer Institute of the NAS of Belarus has developed a design of steam-dynamic thermosiphons (SDT), in which a closed evaporation-condensation cycle of heat transfer is realized. Compared with the use of heat pipes, SDT does not require a complex structure of capillary vessels, ease of manufacture, reliability in operation, and an increase in increased heat transfer capacity.

Steam-dynamic thermosyphons with a flexible condenser

SDTs with a flexible capacitor are designed to transfer heat flow in a horizontal direction over distances of tens to hundreds of meters. Studies of the thermodynamic parameters of a thermosyphon with a condenser 2.5 m long with a pipe outer diameter of 24 mm and simulation of its operation on the stand showed that, depending on the transferred heat load and the size of the annular gap in the condenser channel, there are different modes of flow of the working fluid that determine the characteristics of the device . The SDT condenser can be made flexible in the form of polymer tubes of small diameter. Such SDT is not afraid of corrosion, it can be in the ground for a long time. The efficiency of the SDT is 90%.

Steam-dynamic thermosyphons in solar technologies

SDT as a heat pump heat exchanger (adsorption and absorption) can be used in an adsorption solar cooler to organize sequential refrigerant desorption in two adsorbers. The thermosyphon capacitors are placed along the axis of the cylindrical adsorbers and heat the sorbent from solar radiation. Capacitor length 1 m, thermal resistance R = 0.05 K/W. Utilization of natural heat and cold with the help of a heat exchanger based on SDT and a solar cooler on solid sorbents allows you to increase the efficiency of the air conditioning system in energy-efficient homes up to 65%.

Heat exchangers for indoor air conditioning systems

Heat exchangers on heat pipes and thermosiphons allow intensive heat exchange between the incoming and outgoing air streams, and the sorption heat pump cooler condenses water vapor in the air stream, thus controlling the air humidity at the outlet of the air conditioning system.

Air parameters at the outlet of the air conditioning system:

temperature	20–23 °C
relative humidity (RH)	40–60%

Areas of use:
- with renewable energy sources (solar energy, energy of air, natural reservoirs and soil);
- in various technological processes (economizers for various applications, drying, heating of sidewalks and parking lots for cars, maintaining the desired temperature of asphalt, concrete when transporting them, obtaining biofuels, melting snow and ice on the roofs of buildings, etc.), as well as in ventilation and air conditioning systems;
- in systems for maintaining thermal control in the food / refrigeration industry, foundry, stamping processes and others.

The Institute offers partners:
*a heat exchangers on heat pipes and thermosyphons for air conditioning systems under a manufacturing agreement;
*a heat exchangers on heat pipes and thermosyphons for air conditioning systems under a distribution services agreement.

The innovations of this air conditioning system are:
- an air cooler made on the basis of a solar cooler on solid sorbents using PDT;
- an air cooler made on the basis of PDT (an alternative to a solar refrigerator in the cold season, (when the ambient temperature is lower than the temperature of the incoming air);
- a heat exchanger made on the basis of PDT (heat recovery of the incoming air for heating the air after it has cooled in the refrigerator).

Heat pipe heat exchangers have a number of advantages over traditional heat exchangers:
- high compactness and efficiency of heat recovery (efficiency up to 75%);
- low hydraulic resistance and pressure drop;
- low sensitivity to contamination and dusting of the surface of the heat exchanger;
- the possibility of using the heat exchanger in various media (flue gases, waste water) and a wide temperature range (from -60°C to 1000°C);
- contact of heat pipes with the heat exchanger frame only in one place solves the problem of heat exchanger depressurization due to thermal expansion or compression of heat pipes;
- the ability to efficiently utilize the heat emitted during various technological processes (including ventilation and air conditioning of energy-efficient buildings and residential premises), renewable energy sources;
- improve the environmental conditions of production in various industries and agriculture.

Thermosyphons, 6 m long, designed to heat asphalt and concrete slabs in order to anti-icing and intensive snow melting, were tested in laboratory conditions and showed their good performance.

Thermosiphons over 10 m long have been tested as floor heaters in rooms and dryer panel components for drying wood, grass seeds and grain.

US patent № 4554966 dated 11/26/1985.

A.V.Luikov Heat and Mass Transfer Institute of the National Academy of Sciences of Belarus is the largest scientific institution in the republic dealing with the solution of fundamental and applied problems of heat and mass transfer, fluid dynamics, power engineering, heat engineering, chemical physics, physics of combustion and explosion, nanotechnology, as well as the creation of energy-efficient and environmentally friendly technologies and equipment, apparatus and devices for power engineering and mechanical engineering, agro-industrial complex and construction industry, medicine, chemical, electronic, radio engineering, food industry, space industry.

The Institute carries out scientific, scientific-organizational, and scientific-production interaction with academic and industrial research institutes, universities, design bureaus, associations, and enterprises of Belarus, Russia, Ukraine, Kazakhstan, Moldova, Uzbekistan, Lithuania, Latvia, China, USA, India, Germany, Poland , Czech Republic, Israel, Brazil, Italy, France, and other countries.

Consumers interested in purchasing of heat exchangers on heat pipes and thermosyphons for air conditioning systems under a manufacturing agreement.

Partners interested in purchasing of heat exchangers on heat pipes and thermosyphons for air conditioning systems under a distribution service agreement.