Application of a heat pipe heat exchanger to dehumidification enhancement in a HVAC system for tropical climates—a baseline performance characteristics study

Yau, Yat Huang

doi:10.1016/j.ijthermalsci.2006.02.006

Cited by 76 publications

(49 citation statements)

References 4 publications

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“…To this end, this investigation has been carried out and the aims of this paper are two-fold; investigation into how the enthalpy change across the chilled water coil (CWC) was influenced by each of three key inlet parameters, namely, inlet dry-bulb temperature (DBT), inlet relative humidity (RH) and air mass flux rate. These experimental results, in comparison with those already obtained (Yau, 2006), would also allow an examination of how the reheat recovery with the 8-row HPHX installed was influenced by the same key inlet parameters. Note that the better energy performance could be achieved if the enthalpy change across the active cooling path in the HVAC system is enhanced by installation of a HPHX in the system.…”

Section: Introductionmentioning

confidence: 59%

“…The same experimental set-up and procedures described by Yau (2006) were used for the current investigation, with the exception that in the current investigation, the gate valve in the thermostated chilled water circulator system was used to control the flow rate of the chilled water (i.e. control the cooling capacity of the CWC) for comparison purposes.…”

Section: Experimental Set-up and Proceduresmentioning

confidence: 99%

“…In order to analyse enthalpy change with and without a HPHX installed in the HVAC system, S&P coil (SPC) selection software was used to normalize the State 1 air states (with respect to Figure 1) for all twelve runs of the current experimental series to match the State 1 air states of the experimental runs conducted earlier in the first series of tests with the HPHX installed (Yau, 2006 Yau (2006) and those without the HPHX in the present research), it was not possible to achieve sufficiently close control over the air inlet state to allow a meaningful comparison between the performances of the two systems under the same inlet conditions.…”

Section: Coil Selection Software Simulation For Comparison Purposesmentioning

confidence: 99%

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Analysis of enthalpy change with/without a heat pipe heat exchanger in a tropical air conditioning system

Yau¹

2006

Int. J. Energy Res.

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SUMMARYIn an earlier paper (Yau, 2006. Application of a heat pipe heat exchanger to dehumidification enhancement in tropical HVAC systems}a baseline performance characteristics study. Int. J. Thermal Sci., accepted for publication), the baseline performance characteristics of the 8-row wickless heat pipe heat exchanger (HPHX) were established for it being used in a vertical configuration under tropical climate conditions. The present paper covers the tests and simulation conducted on the same experimental HVAC system without the HPHX installed, thereby determining the enthalpy change for the air passing through the chilled water coil (CWC) alone (i.e. without the pre-cooling or reheating effect of the HPHX). These experimental results, in comparison with those already obtained, would also allow an examination of how the reheat recovery with the 8-row HPHX installed was influenced by the same key inlet parameters. The final results show that the enthalpy change with a HPHX installed for all cases examined are significantly higher than enthalpy change without a HPHX installed, demonstrating that the cooling capability of the CWC was enhanced by the HPHX.

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Section: Introductionmentioning

confidence: 59%

Section: Experimental Set-up and Proceduresmentioning

confidence: 99%

Section: Coil Selection Software Simulation For Comparison Purposesmentioning

confidence: 99%

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Analysis of enthalpy change with/without a heat pipe heat exchanger in a tropical air conditioning system

Yau¹

2006

Int. J. Energy Res.

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“…2. Investigation of the effectiveness coefficient for calculating the performance of the heat pipe heat exchanger itself rather than the whole HVAC system (Yau 2007b). …”

Section: Overview Of Relevant Theorymentioning

confidence: 99%

Investigation of heat pipe heat exchanger effectiveness and energy saving in air conditioning systems using silver nanofluid

Firouzfar

Soltanieh

Noie

et al. 2012

Int. J. Environ. Sci. Technol.

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The present study attempts to use the methanol-silver nanofluid filled heat pipe heat exchanger and compares the effectiveness as well as the energy saving with pure methanol. A heat pipe heat exchanger has been tested in a test rig under steady-state conditions. The lengths of both the evaporator and the condenser sections of the heat exchanger were 700 mm, and its central adiabatic section had a length of 160 mm. The heat exchanger had 36 plate finned copper thermosyphons arranged in three rows. The inlet air temperature across the evaporator section was varied in the range of 33-43°C while the inlet air temperature to the condenser section was nearly constant to be 13°C. First, pure methanol was used as the working fluid with a fill ratio of 50 % of the evaporator section length, and then dilute dispersion of silver nanoparticles in methanol was employed as the working fluid. The nanofluid used in the present study is 20 nm diameter silver nanoparticles. The experiments were performed to compare the heat pipe heat exchanger effectiveness and energy saving, using nanofluid and pure methanol. The inlet air relative humidity across the evaporator section was varied between 35 and 80 %. The sensible effectiveness of the heat pipe heat exchanger obtained from experiments varied about 5-22 % for pure methanol and 9-32 % for methanol-silver nanofluid. Based on these experimental results, using methanol-silver nanofluid leads to energy saving around 8.8-31.5 % for cooling and 18-100 % for reheating the supply air stream in an air conditioning system.

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“…In another study by Srimuang et al [7] the application of heat pipe heat exchangers for heat recovery focused on the energy savings and provideing additional information for the design of heat pipe heat exchangers with optimum conditions in heat recovery systems was reviewed. Yau [8][9][10][11][12] conducted a series of experimental studies on the use of HP technology for tropical climates and gave a review of research on the application of heat pipe heat exchangers in air conditioning systems.…”

Section: Introductionmentioning

confidence: 99%

Research on Energy Saving Potential for Dedicated Ventilation Systems Based on Heat Recovery Technology

Zhang

2014

Energies

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Abstract:Research results have identified the use of heat pipe heat exchangers (HPHXs) for heat recovery as a way to reduce the pre-cooling and re-heating energy. This paper suggests decoupling dehumidification from cooling to reduce energy consumption. The feasible usage and the energy saving potential of heat pipe heat exchanger at the air handler dedicated in accomplishing this objective is investigated. In this paper a dedicated ventilation system combined with a HPHX to reduce energy consumption is tested and investigated under varying conditions by laboratory experiments. The energy saving potential and heat pipe (HP) effectiveness are tested and calculated under various outdoor conditions. The simulation and experimental results demonstrate that for all cases examined, the average HP effectiveness and energy savings have the same trend at various outdoor temperatures and Relative Humidity (RH) values. It has been found that the heat pipe can be applied to save over 60% energy for the air-conditioning operating hours. The reduction in overall energy is from 1.8% to 2.8% for the whole system. Therefore, the results confirm that the proposed set-up is useful for buildings to achieve intended energy saving objectives in subtropical climates where air-conditioning demand is highly variable.

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Application of a heat pipe heat exchanger to dehumidification enhancement in a HVAC system for tropical climates—a baseline performance characteristics study

Cited by 76 publications

References 4 publications

Analysis of enthalpy change with/without a heat pipe heat exchanger in a tropical air conditioning system

Analysis of enthalpy change with/without a heat pipe heat exchanger in a tropical air conditioning system

Investigation of heat pipe heat exchanger effectiveness and energy saving in air conditioning systems using silver nanofluid

Research on Energy Saving Potential for Dedicated Ventilation Systems Based on Heat Recovery Technology

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