BITS Faculty Publications

Permanent URI for this communityhttp://localhost:4000/handle/123456789/1867

Browse

Filters

2015 - 20162

Settings

Author: search.filters.author.Dasgupta, Mani SankarSubject: search.filters.subject.Thermodynamic analysis

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    A Trans-critical CO2 Heat Pump System for Waste Heat Utilization in Warm Weather Condition Applied to a Milk Refrigeration Plant
    (Bepress, 2016) Dasgupta, Mani Sankar
    Based on field data from a medium scale ammonia based milk refrigeration plant located in northern part of India, a trans-critical CO2 based heat pump system is conceptualized to utilize the waste heat from the plant to improve overall coefficient of performance. Year round plant operating data is collected. The plant handles between 0.1 to 0.15 million liters of milk and milk products daily. It maintains two cooling chambers, one at 4°C and the other at -10°C. Every ten days it is required to replenish a 5000 liter tank with ground water for evaporative cooling of the system. Up-stream and down-stream processes in the milk processing plant utilizes a coal fired boiler system which also uses ground water. In this study, the condenser of the ammonia based refrigeration system is coupled with the evaporator of the proposed CO2 trans-critical heat pump system which is maintained at 25°C round the year. The heat pump delivers heat at about 70°C to pre heat the boiler feed water available in temperature range 22-25°C round the year. Augmentation of the proposed CO2 system is able to reduce coal consumption by utilizing the waste heat from the ammonia system at the same time reduce ground water utilized by eliminating evaporative cooling. The proposed heat pump system has encouraging COP and is designed to be largely independent of variation in ambient temperature. Based on field data, a comparative study is carried out using thermodynamic & thermo-economic analysis for a duration of one year to establish feasibility of the proposed system
  • No Thumbnail Available
    Item
    Thermodynamic analysis of trans-critical CO2 refrigeration cycle in Indian context
    (IJSTA, 2015) Dasgupta, Mani Sankar
    The coefficient of performance for CO2 based trans-critical system is lower at high ambient temperature regions like India due to higher energy required for compression to a high temperature beyond critical point. This paper presents thermodynamic analysis of a basic trans-critical CO2 refrigeration cycle. Further, the basic cycle is modified for two different configurations incorporating parallel compression and inter-cooling. Use of parallel compression and inter-cooling in cycle configuration are two of the most promising cycle modifications for improving the performance of trans-critical CO2 refrigeration systems operating at high ambient temperatures. Simulation results show that parallel compression configuration is more effective. The maximum improvement in COP obtained is about 25% for parallel compression configuration. Also, the operating pressure of gas cooler is found lower for parallel compression configuration.