Capacity modulation of an inverter heat pump system with capillary tubes and TXV
The capacity of an air-to-air heat pump is decreased as the outdoor temperature is raised in the cooling mode operation. Capacity control of a heat pump system with respect to the outdoor temperature is required to provide adequate capacity at high condensing temperature condition on the heating mode operation of the system. An experimental study was performed on the characteristics of an inverter driven water-to-water heat pump system with a variation of compressor frequency and expansion device. The frequency was altered from 30 Hz to 75 Hz. Capillary tubes (700, 800, 900 mm) and thermostatic expansion valve (TXV) were used as an expansion device, and their results were compared. Performance of the system was measured at various condenser (30, 34, 39 C) and evaporator (26.1, 28.5 C) inlet temperatures of the secondary fluids. The system with longer capillary tube had higher increase of capacity and COP at high secondary fluid temperature entering the condenser. As the frequency was raised, the capacity and COP of the system with shorter capillary tube increased more than that with longer capillary tube, and capacity and COP of the TXV system was enhanced more than the capillary tube system.
- Research Organization:
- Korea Univ. (KR)
- OSTI ID:
- 20026734
- Resource Relation:
- Conference: Renewable and advanced energy systems for the 21st Century, Maui, HI (US), 04/11/1999--04/15/1999; Other Information: 1 CD-ROM. Operating system required: Windows i386(tm), i486(tm), Pentium (R) or Pentium Pro, MS Windows 3.1, 95, or NT 3.51, 8 MB RAM; MacIntosh and Power MacIntosh with a 68020 or greater processor, System software version 7.1, 3.5 MB RAM (5 MB for PowerMac) 6 MB available hard-disk space; UNIX; PBD: 1999; Related Information: In: Renewable and advanced energy systems for the 21st century, RAES'99 proceedings, by Hogan, R.; Kim, Y.; Kleis, S.; O'Neal, D.; Tanaka, T. [eds.], [1125] pages.
- Country of Publication:
- United States
- Language:
- English
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