CO2 HEAT PUMPS FOR COMMERCIAL BUILDING APPLICATIONS WITH SIMULTANEOUS HEATING AND COOLING DEMAND

Many commercial buildings, including data centers, hotels and hospitals, have a simultaneous heating and cooling demand depending on the season, occupation and auxiliary equipment. A data center on the Purdue University, West Lafayette campus is used as a case study. The electrical equipment in data centers produce heat, which must be removed to prevent the equipment temperature from rising to a certain level. With proper integration, this heat has the potential to be used as a cost-effective energy source for heating the building in which the data center resides or the near-by buildings. The proposed heat pump system utilizes carbon dioxide with global warming potential of 1, as the refrigerant. System simulations are carried out to determine the feasibility of the system for a 12-month period. In addition, energy, environmental and economic analyses are carried out to show the benefits of this alternative technology when compared to the conventional system currently installed in the facility. Primary energy savings of ~28% to ~61%, a payback period of 3 to 4.5 years and a decrease in the environmental impact value by ~36% makes this system an attractive option. The results are then extended to other commercial buildings

Review on Ushirasava (fermented traditional medicine of Ayurveda)

Sandhana Kalpana is very common Kalpana described in Ayurvedic literature. We can found many footprints of Sandhana Kalpana in Vedas also. Asava and Arishta are popularly used in Ayurvedic practice. These preparations occupy unique position in pharmaceutics on account of their superiority to other preparations. Ushirasava is one of the important Asava among them. Ushirasava / Usheerasava is a liquid Ayurvedic medicine used in treatment of bleeding disorders. This medicine is cooling in nature and is prescribed in the diseases which occur due to the excessive heat in body. Hence this medicine pacifies the excess Pitta Dosha in body

Analysis of a Data Center Using Liquid-Liquid CO2 Heat Pump for Simultaneous Cooling and Heating

Liquid–liquid CO2 heat pump systems are a promising technology for commercial building applications, which require simultaneous heating and cooling. This paper presents the investigation of a data center on the Purdue University, West Lafayette campus. The data center located in the Department of Mathematics is the most energy intensive data center on campus. The cooling load of the data center is approximately 750 kW/hour. The heating season in West Lafayette is 7 to 8 months and the heating load of the buildings is very high during the coldest months. The heating load of the Mathematics building can go to as high as 600 kW/hour during the coldest days of the year. To suffice this simultaneous cooling and heating demand, a liquid-liquid CO2 heat pump is proposed. Presently, the cooling load of the data center is met by eight electrically driven and four steam-driven chillers and the heating load is satisfied by two coal fired and two natural gas boilers. Simulations are performed to compare the proposed CO2 heat pump system with the present system. The assessment shows noteworthy fuel savings and reduction in the CO2 emissions with the system working with a coefficient of performance (COP) of 6.19. If the CO2 heat pump system is installed, 574.92m3/day of natural gas and 751.68 kg/day of coal could be saved on a cold day. The system has the potential to reduce CO2 emissions by 2980.76 kg/day

Experimental Study of a CO2 Thermal Battery for Simultaneous Cooling and Heating Applications

This paper presents experimental investigations of the dynamics of a transcritical CO2 heat pump system with two thermal storages for simultaneous cooling and heating application. The preliminary results of the thermal battery are provided using a small-scale test bed that shows the accelerated penetration of renewable energy sources for building heating and cooling applications. The experimental system consists of a CO2 heat pump system with a compressor of 3 kW (1.02x104 BTU/hr) cooling capacity and two water tanks. During operation, the compressor and expansion valve are considered quasi-static. Thermal sensors are located in each of the two tanks to monitor the temperature gradient of water along the vertical orientation of the tank which impacts the overall system performance. Experiments are carried out under different water circulation flow rates for both the gas cooler and the evaporator in the heat pump, as well as under various discharge pressure conditions controlled by different charging rates and expansion valve openings. The impacts of water circulation flow rate and valve opening are reported in an effort to find the optimum coefficient-of-performance (COP). The results show that increasing the water inlet temperature in the gas cooler raises the discharge pressure significantly and drops the COP, whereas increasing the water temperature of the evaporator raises the discharge pressure relatively moderately. Although a larger water flow rate enhances the heat exchanger capacity and system COP, a smaller water flow rate seems to be preferable to maintain the thermal profile of the water tanks and to provide a more stable COP. At higher gas cooler water inlet temperature, the COP tends to increase with closing expansion valve. In this particular setup, the best COP is found to be approximately 7.0 at a specific expansion valve opening and at a discharge pressure between 75 and 83 bars (1088 to 1204 psia). The heating COP negatively corresponds to the water temperature at the gas cooler inlet. Experiments suggest the need of a proper control strategy and a matched tank capacity design. Based on these results, a 20% power enhancement may be possible by controlling the hot and cold water flow rates

Mirror Mirror on the Wall

36-38Sadashiv Mohite lay dead before the big mirror. Kiran was standing near the body, with the murder weapon in his hand, blood still sloshing through the fresh wound. Two days back Kiran had a fight with him on the street in full view of all and Sadashiv, revenge in his mind, was waiting for Kiran to give him a good thrashing. But now, he himself lay dead at Kiran’s feet. </span

Fiction - The Chimp

36-39Dr Eric Thompson was sitting on his haunches. At the edge of the precipice, he did not care a whit for the depth to which he would be flung to the river flowing way down

Time Thief

36-38There was a hoarse cry from the man as he slumped helplessly on a chair.  It seemed as if he had lost all his energy.  Inspector Rane was looking at him with unbelieving eyes.  Slowly and slowly the man was changing.  His beautiful hair was falling about him, balding him.  The hair on his nape was graying.  His eyes, going inside their sockets were getting smaller and smaller.  Wrinkles on his forehead, cheeks shrunk.  His well-built body receded – his clothes hanging loose.  He looked like a man more than fifty. “Why,you look old!  What happened to you allof a sudden!” cried his wife. Inspector Rane was looking at him astounded, as if he were seeing a horror film.  Humans attain old age slowly over many years in a dignified way, but getting old all of a sudden – in a matter of minutes – and that too old by twenty years in such an unbelievably short time was a most unlikely happening. But it was all happening before him

Electrical Conductivity Properties of Newly Synthesized Melamine - Aniline - Formaldehyde Terpolymer and its Polychelate

Terpolymer MAF synthesized by the polycondensation of melamine (M) and aniline (A) with formaldehyde (F) in the presence of an acid catalyst in 1:1:3 molar proportions of the reacting monomers. Polychelates were prepared by using metal acetate, metal salts and MAF ligand in DMF medium. The prepared terpolymer and its polychelates were characterized by using elemental analysis, magnetic studies and spectral analysis. In the present paper, electrical conductivity properties of the terpolymer and its polychelates were studied over a wide range of temperature and is in the order MAF <Mn(II)<Fe(III) and <Co(II). The of log σversus 1/T. Activation energy values lie in the range of 0.847 eV to 1.156 eV. On the basis of electrical conductivity measurements of terpolymer and its polychelates, it was found that, at higher temperature conductivity increases linearly, showing semi conducting behaviour and hence useful in electronic industry

Stage change from clinical N0 to pathological N+ neck: A retrospective analysis of 169 patients

Aim: To find the incidence of upstaging from clinical N0 to pathological N+ in our study. Materials and Methods: This retrospective analysis of 169 patients was performed from January 1, 2015, to December 31, 2015. Out of these 169 patients, 97 were operated. Histopathological records of 87 patients were available and hence, included in this study. Rest of the patients were excluded from the study. Results: In these 87 operated patients, 26 patients had upstaging of the disease based on nodal status histopathologically. Out of these 26 patients, 11 patients had clinically N0 necks; however, due to their T size, elective radical neck dissections were performed. Histopathological reports show pathologically N-positive neck with their stage to get upgraded from N0 to N+ which had a direct influence on postoperative treatment management of the patients influencing the prognosis. Tongue cancers were upstaged more with 46.15% compared to other sites followed by buccal mucosa cancers with 38.45%. Conclusion: Pathologic lymph node staging, based on a staging or elective radical neck dissection, should be considered for patients treated for squamous cell carcinoma of oral cavity to identify high-risk patients who may benefit from postoperative adjuvant therapy such as radiation/chemotherapy. Prospective studies in large numbers are still essential to validate these findings before pathologic lymph node staging is also included in standard tumor node metastasis staging criteria