Experimental Analysis of the Vapour Compression Refrigeration System with Microchannel Condenser using R134a and R1234yf Refrigerant

Vapour Compression Refrigeration (VCR) system with high COP, low input power consumption and minimal exergy losses are of great research hotspot. The current research focuses on analysis of exergy and performance of vapour compression refrigeration (VCR) cycle is in a real-world application. Experiments were carried out in the VCR system using round tube condenser and microchannel condenser along with different refrigerants R134a, and R1234yf. Temperatures were varied from +20°C to 5°C for the evaporator and 40°C to 50°C for the condenser. Among the two refrigerants, experimental results show that refrigerants operating in micro-channel condensers have COP of 6% and 4%greater higher with5% and 3% lower exergy loss compared to the round tube condenser for R134a and R1234yf respectively.R1234yf appears to be a better equivalent for R134a, according to the findings. The efficiency defect in the condenser is the greatest and least in the evaporator for the coolants examined.

Design improvement and experimental study on shell and tube condenser for bio-oil recovery from fast pyrolysis of wheat straw biomass

In this study, the design improvement was done in a shell and tube condenser for improved heat transfer and condensation of bio-oil vapour. The developed condenser has split shell and segmental baffles, which divide the shell in various zones and condensate collection points. The fast pyrolysis of wheat straw was done and the bio-oil vapour condensate collected from various outlets located at bottom of condenser shell. From experimental results it was found that production of bio-oil increased from 10.2 to 20.8% with increase in cooling water flow rate from 1000 to 2500 L/h; but, further increasing it beyond 2500 L/h provide marginal effects on production of bio-oil. The production of bio-oil increased from 15.2 to 20.7% as sweep gas flow rate was increased from 20 to 40 L/min at 2500 L/h of cooling water flow rate. But, further increase in sweep gas flow rate beyond 40 L/min resulted in to decrease in production of bio-oil. The novelty of this work is development of improved condenser with segmental baffles, which help in fractional condensation of bio-oil vapour, split shell for cleaning of outer surface of the cooling water tubes and compact design of condenser for optimal condensation of bio-oil.

Experimentation and Performance Analysis of Natural Draft Wire on Tube Condenser

This project is sponsored by the company Whirlpool of India Limited, situated at Ranjangaon MIDC, Pune. A simple design methodology of Wire on Tube heat exchanger used in domestic refrigeration systems focuses on both energy saving and cost reduction in this study. A wire on tube condenser is two-phase natural convection heat exchanger which rejects heat absorbed by the refrigerant in the evaporator and heat addition by compressor to atmospheric temperature changing its phase. The main objective of this research paper is to study impact of condenser tube length and number of wires, its pitches on performance of domestic refrigerator and desire to find optimum design of wire on tube heat exchanger compatible with on/off compressor in 185 liter 3 star single door model. Mathematical model are used to analyze performance of entire refrigeration system. Experiments were conducted under controlled climatic chamber and varying ambient temperature as per BEE standard and procedures. It was found that experimental results have 5% to 8% deviation range with results obtained from mathematical model. Optimum design of wire on tube heat exchanger selected has main focus on both energy saving and cost reduction