暖通外文翻譯----地源熱泵系統(tǒng)的建模和性能評估（英文）

1、Modeling and performance evaluation of ground source (geothermal) heat pump systemsOnder Ozgener a, Arif Hepbasli b,*a Solar Energy Institute, Ege University, 35100 Bornova, Izmir, Turkey b Department of Mechanical Engin

2、eering, Faculty of Engineering, Ege University, 35100 Bornova, Izmir, TurkeyReceived 6 December 2005; received in revised form 23 April 2006; accepted 30 April 2006AbstractThis study deals with the energetic and exergeti

3、c modeling of ground source heat pump (GSHP) systems for the system analysis and performance assessment. The analysis covers two various GSHPs, namely a solar assisted vertical GSHP and horizontal GSHP. The performances

4、of both GSHP systems are evaluated using energy and exergy analysis method based on the experimental data. Energy and exergy specifications are also presented in tables. Some thermodynamic parameters, such as fuel deplet

5、ion ratio, relative irreversibility, productivity lack and exergetic factor, are investigated for both systems. The results obtained are discussed in terms of energetic and exergetic aspects. The values for COPHP ranged

6、from 3.12 to 3.64, while those for COPsys varied between 2.72 and 3.43. The exergy efficiency peak values for both whole systems on a product/fuel basis were in the range of 80.7% and 86.13%. It is expected that the mode

7、l presented here would be beneficial to everyone dealing with the design, simulation and testing of GSHP systems. # 2006 Elsevier B.V. All rights reserved.Keywords: Building; Energy; Exergy; Exergy analysis; Geothermal e

8、nergy; Ground source heat pump; Renewable energy1. IntroductionGround-coupled heat pump systems are increasingly deployed for heating and air-conditioning in commercial and institutional buildings as well as in residenti

9、al ones. These systems consist of a sealed loop of pipe, buried in the ground and connected to a heat pump through which water/antifreeze is circulated. For the ground-loop heat exchangers, vertical borehole configuratio

10、n is usually preferred over horizontal trench systems because less ground areas are required. The vertical ground heat exchanger consists of a number of boreholes, each containing a U-tube pipe. The depth of the borehole

11、 ranges usually between 40 and 150 m, and the diameter 0.075–0.15 m. The borehole annulus should be grouted with materials that provide thermal contact between the pipe and the surrounding soil/rock and to protect ground

12、water from possible contamination. The efficiency ofGSHP systems are inherently higher than that of air source heat pumps because the ground maintains a relatively stable source/ sink temperature [1,2]. The use of ground

13、 source heat pumps (GSHPs) in commercial and residential buildings is a tremendous example. A GSHP utilizes the ground as a heat source in heating and a heat sink in cooling mode operation. In the heating mode, a GSHP ab

14、sorbs heat from the ground and uses it to heat the house or building. In the cooling mode, heat is absorbed from the conditioned space and transferred to the earth through its ground heat exchanger. GSHPs are an efficien

15、t alternative to conventional methods of conditioning homes because they utilize the ground as an energy source or sink instead of using the ambient air. The ground is a thermally more stable heat exchange medium than ai

16、r, essentially unlimited and always available. The GSHPs exchange heat with the ground, and maintain a high level of performance even in colder climates. The ground heat exchanger used in conjunction with a closed- loop

17、GSHP system consists of a system of long plastic pipes buried vertically or horizontally in the ground [1–4]. In a comprehensive study performed by Lund et al. [5], it is reported that GSHPs have the largest energy use a

18、nd installed capacity according to the 2005 data, accounting for 54.4% andwww.elsevier.com/locate/enbuildEnergy and Buildings 39 (2007) 66–75* Corresponding author. Tel.: +90 232 343 4000x5124; fax: +90 232 388 8562. E-m

19、ail addresses: Onder.Ozgener@ege.edu.tr (O. Ozgener),Arif.Hepbasli@ege.edu.tr (A. Hepbasli).0378-7788/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2006.04.019ethyl glycol mixture b

20、y weight was prepared. The refrigerant circuit was built on the closed loop copper tubing. The working fluid is R-22. The solar assisted ground source heat pump system studied was installed at Solar Energy Institute of E

21、ge University (latitude 388240N, longitude 278500E), Izmir, Turkey.2.2. Ground source heat pump system IIThe GSHP system II theoretically designed as shown inFig. 2. Some similar applications of these systems are availab

22、le in the literature (e.g. [4,13]). It will heat and cool aO. Ozgener, A. Hepbasli / Energy and Buildings 39 (2007) 66–75 68Fig. 1. Schematic of the solar assisted ground source heat pump system [8–10].Table 1 Measured p

23、arameters along with their total uncertainties of the ground source heat pump system I in average [8–10]Item Nominal value Unit Total uncertainty (%)Average maximum energy consumption of all system 1.335 kW ?1.02 Average

24、 power input to the compressor 0.806 kW ?1.02 Power input to each one of the brine and water circulating pumps 0.030 kW ?1.02 Total power input to the fan of the fan-coil unit 0.048 kW ?1.02 Current of antifreeze solutio

25、n circulating pump at the ground heat exchanger side 0.33 A ?1.02 Current of the water circulating pump at the fan coil side 0.33 A ?1.02 Maximum phase to phase voltage (VLL) 407 V ?1.02 Average/maximum phase voltages (V

26、/VLN) 220/232 V ?1.02 Average phase to phase voltage 380 V ?1.02 Total maximum current (SA) 4.93 A ?1.02 Frequency (Hz) 50 Hz ?1.02 Average power factor (cos C) 0.80 Dimensionless ?1.02 Average evaporation/condensation (

27、low/high) pressures 0.425/2.8 MPa ?3.32 Average evaporating/condensing temperatures ?3/66.75 8C ?3.33 Temperatures of water at the inlet and outlet of ground-heat exchanger 9.1/12.36 8C ?1.59 Average temperature of water

28、 at solar collector outlet 13.01 8C ?1.59 Supply/return water temperatures of the fan-coil unit 52/42 8C ?1.59 Volumetric flow rates of the brine/refrigerant 0.0002/0.0186 ? 10?3 m3/s ?3.01/?1.50 Outdoor/solar collector

29、surface temperatures 0/10 8C ?1.59 Outdoor/laboratory inside design relative humidities 60.47/43 % ?1.02 Solar radiation outside the laboratory 138.59 W/m ?0.80Wind velocity at a height of 12 m 3.39 m/s ?2.00 Length (wid