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Journal ArticleDOI

Theoretical and experimental investigations on horizontal heat pipe heat exchangers using a composite wick structure for heat recovery in air-conditioning systems

19 May 2017-Science and Technology for the Built Environment (Taylor & Francis)-Vol. 23, Iss: 4, pp 557-566
Abstract: The literature review indicates that, though water has a good figure of merit, very limited information is available on the use of water as the working fluid in a horizontal heat pipe heat exchanger for air conditioning applications. This article investigates theoretical and experimental analyses of horizontal heat pipe heat exchangers for air conditioning applications using distilled water as the working fluid. This heat pipe heat exchanger study consists of 20 copper tubes of 9.5 mm outside diameter arranged in two rows with a 0.3 m evaporator length, a 0.3 m condenser length, a 0.05 m adiabatic length, and 12 fins per inch of aluminum plate fins. A comparative analysis is studied for two configurations of heat pipe heat exchangers. The first configuration of heat pipe heat exchanger consists of a single wick structure with two layers of 180 mesh of phosphor bronze wire mesh, and, in the second configuration, the heat pipe heat exchanger consists of a composite wick structure (two layers of 180 mesh and...
Topics: Plate fin heat exchanger (73%), Micro heat exchanger (73%), Micro-loop heat pipe (71%), Plate heat exchanger (70%), Heat spreader (69%)
Citations
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Book
01 Nov 1985-
Abstract: Instrumentation, Measurement and Analysis , Instrumentation, Measurement and Analysis , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

77 citations


References
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Book
28 Sep 1994-
Abstract: Background Information. Capillary Limitation in Heat Pipes and Thermosyphons. Other Operating Limits. Modeling Heat Pipe Performance. Types and Classification of Heat Pipes. Design and Manufacturing Considerations. Heat Pipe Testing and Analysis. Heat Pipe Applications in the Electronics Industry. Appendices. Indexes.

499 citations


"Theoretical and experimental invest..." refers background or methods in this paper

  • ...The inside resistance due to boiling and condensation was neglected, as its values are comparatively very small due to larger values of heat transfer coefficient (Chi 1976; Peterson 1994)....

    [...]

  • ...…= (U A)eCe (3) NTUc = (U A)cCc (4) where U A = 1 Rtotal (4.1) Rtotal = Rconv0 + Rcondp + Rcondw (4.2) The inside resistance due to boiling and condensation was neglected, as its values are comparatively very small due to larger values of heat transfer coefficient (Chi 1976; Peterson 1994)....

    [...]

  • ...The operating limits of HPHX 1 and HPHX 2 were calculated as per the procedures mentioned in the literature (Chi 1976; Peterson 1994; Reay et al. 2014) and are summarized in Table 2....

    [...]


Book
01 Jun 1990-
Abstract: This book is covered under the following headings: Basic {epsilon}-N{sub tu} analysis for complicated flow arrangements; Single-phase heat transfer and pressure drop measurements, correlations and predictions; and Applications of compact heat exchangers.

483 citations


"Theoretical and experimental invest..." refers methods in this paper

  • ...The theoretical effectiveness of the HPHX is calculated as per the procedure mentioned in the available literature (Noie 2006; Kays and London 1964) and is summarized below....

    [...]


Book
01 Jan 1976-

193 citations


"Theoretical and experimental invest..." refers background or methods in this paper

  • ...The inside resistance due to boiling and condensation was neglected, as its values are comparatively very small due to larger values of heat transfer coefficient (Chi 1976; Peterson 1994)....

    [...]

  • ...…= (U A)eCe (3) NTUc = (U A)cCc (4) where U A = 1 Rtotal (4.1) Rtotal = Rconv0 + Rcondp + Rcondw (4.2) The inside resistance due to boiling and condensation was neglected, as its values are comparatively very small due to larger values of heat transfer coefficient (Chi 1976; Peterson 1994)....

    [...]

  • ...Among the many outstanding advantages of using a heat pipe as a heat transmission device are constructional simplicity, exceptional flexibility, accessibility to control, and ability to transport heat at a high rate over a considerable distance with an extremely small temperature drop (Chi 1976)....

    [...]

  • ...The operating limits of HPHX 1 and HPHX 2 were calculated as per the procedures mentioned in the literature (Chi 1976; Peterson 1994; Reay et al. 2014) and are summarized in Table 2....

    [...]


Journal ArticleDOI
Abstract: The heat pipe heat exchangers are used in heat recovery applications to cool the incoming fresh air in air conditioning applications. Two streams of fresh and return air have been connected with heat pipe heat exchanger to investigate the thermal performance and effectiveness of heat recovery system. Ratios of mass flow rate between return and fresh air of 1, 1.5 and 2.3 have been adapted to validate the heat transfer and the temperature change of fresh air. Fresh air inlet temperature of 32–40 °C has been controlled, while the inlet return air temperature is kept constant at about 26 °C. The results showed that the temperature changes of fresh and return air are increased with the increase of inlet temperature of fresh air. The effectiveness and heat transfer for both evaporator and condenser sections are also increased to about 48%, when the inlet fresh air temperature is increased to 40 °C. The effect of mass flow rate ratio on effectiveness is positive for evaporator side and negative for condenser side. The enthalpy ratio between the heat recovery and conventional air mixing is increased to about 85% with increasing fresh air inlet temperature. The optimum effectiveness of heat pipe heat exchanger is estimated and compared with the present experimental data. The results showed that the effectiveness is close to the optimum effectiveness at fresh air inlet temperature near the fluid operating temperature of heat pipes.

186 citations


Journal ArticleDOI
Abstract: Research has been carried out on the theory, design and construction of heat pipes, especially their use in heat pipe heat exchangers for energy recovery, reduction of air pollution and environmental conservation. A heat pipe heat exchanger has been designed and constructed for heat recovery in hospital and laboratories, where the air must be changed up to 40 times per hour. In this research, the characteristic design and heat transfer limitations of single heat pipes for three types of wick and three working fluids have been investigated, initially through computer simulation. Construction of heat pipes, including washing, inserting the wick, creating the vacuum, injecting the fluid and installation have also been carried out. After obtaining the appropriate heat flux, the air-to-air heat pipe heat exchanger was designed, constructed and tested under low temperature (15–55°C) operating conditions, using methanol as the working fluid. Experimental results for absorbed heat by the evaporator section are very close to the heat transfer rate obtained from computer simulation. Considering the fact that this is one of the first practical applications of heat pipe heat exchangers, it has given informative results and paved the way for further research.

159 citations


Performance
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No. of citations received by the Paper in previous years
YearCitations
19851