A design procedure for gravity-assisted heat pipe heat exchanger

Investigation of thermal performance of an air-to-air thermosyphon heat exchanger using ε-NTU method

“…However, since the vapor inside a heat pipe is almost at constant temperature, its specific heat, c p , and capacity rate, C L , become by definition, equal to infinity and as a result C h /C L = C c /C L = 0. Therefore, the effectiveness-NTU equations for a single row heat pipe heat exchanger are as follows [14]:…”

“…Now for a heat pipe heat exchanger with n rows of heat pipes in the direction of flow, the following effectiveness-NTU equations are given [14]: For the evaporator section:…”

Performance Analysis and Test of a Two-Phase Closed Thermosyphon Heat Exchanger

“…stulc et al [3] reported an intensive study of various heat pipe heat exchangers for use in heat recovery. Azad and Goola [4] developed a design procedure for gravity-assisted heat pipe heat exchangers. The variations of overall effectiveness with various design parameters were presented and discussed.…”

Applications of Heat Pipes to Energy Systems at Irost

“…Heat pipes are ideally suited for various types of waste heat recovery applications. The different heat pipe heat exchangers are described below Azad and Geoola (1984) presented a theoretical approach for the design of gravity-assisted heat pipe heat exchangers (GAHPHEs). A heat pipe heat exchanger used for air-to-air heat recovery is essentially a nest of finned heat pipes which appears similar to conventional steam coils.…”

“…The coupling fluid is the heat pipe working fluid with capillary forces which are used as the pump, Fig. 1(b) (Azad and Geoola 1984 …”