Loading...
Search
Search in this resource
sort by
Send to Friend
 Digital Object List
 Bookmark
 Review List
  1. بررسی تأثیر استفاده از مخلوط مبرد زئوتروپیک در کارایی و عملکرد پمپ حرارتی متصل به زمین عمودی
بررسی تأثیر استفاده از مخلوط مبرد زئوتروپیک در کارایی و عملکرد پمپ حرارتی متصل به زمین عمودی
665 viewed

بررسی تأثیر استفاده از مخلوط مبرد زئوتروپیک در کارایی و عملکرد پمپ حرارتی متصل به زمین عمودی

مقنی، رضا Moghanni, Reza

Studying the Effect of Using Zeotropic Refrigerant Mixtures on the Performance of the Vertical Ground Coupled Heat Pump

Moghanni, Reza | 2021

665 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 54359 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Hakkaki Fard, Ali; Kazemzadeh Hannani, Siamak
  7. Abstract:
  8. Vertical ground-coupled heat pumps due to using a renewable energy stored in the ground and being away from ambient temperature fluctuations have a good coefficient of performance and very low pollution. Despite these advantages, these systems have not gained a pervasive position in the field of heating/cooling systems due to their high initial cost. Despite these advantages, these systems have not gained a pervasive position among communities due to their high initial cost. In the present project, a comprehensive study has been conducted to investigate the effect of using zeotropic refrigerant mixtures on the performance of vertical ground-coupled heat pumps and reducing its initial costs. Also, in this study, the effect of various factors on the maximum use of the zeotropic refrigerant mixture benefits, improving system performance, and reducing its costs have been investigated. These various effective factors include the use of constant and variable speed pumps and compressors, three different depths of boreholes, three types of climate, five and 20-year operating periods, and design constraints. The refrigerants studied include R22 and R410a refrigerants and three zeotropic refrigerants mixtures R32/R134a with the ratio of (50/50), R32/R134a/R125 with the ratio of (70/15/15), and R32/CO2 with the ratio of (80/20). In order to simulate a vertical ground-coupled heat pump, in the first step, the analytical modeling of the ground heat exchanger has been done using an improved finite line source model and quasi-three-dimensional resistance model. In the next step, the heat pump components are modeled. These modelings have been validated by numerical and experimental studies. The five-year and 20-year simulations were performed based on the recommended constraints of ASHARE standard, and then with the help of the constraints proposed in this study, 20-year simulations were performed and compared with the previous results. According to the results, the coefficient of performance of the zeotropic refrigerant mixture R32/R134a (50/50) is as good as R22 refrigerant, while its compressor size is 23% smaller than R22 refrigerant and environmentally, its global warming potential is 42% lower than R22, and its ozone depletion potential is zero. Also, constant speed compressor and variable speed pump optimize the ground heat exchanger's performance and make maximum use of the zeotropic refrigerant mixture benefits. According to the study results, the design constraints proposed in this project, while ensuring the proper performance of the system, reduce the length of the ground heat exchanger by 30 to 45% and thus the initial cost of the system
  9. Keywords:
  10. Renewable Energy Resources ; Analytical Modeling ; Vertical Ground Coupled Heat Pump System ; Zeotropic Refrigerant Mixture ; Vertical Ground Heat Exchanger ; Vertical Ground Coupled Heat Pump ; Finite Line Source Model

 Digital Object List

 Bookmark

No TOC