The ground source heat pump heating system is considered as one of the best solutions for transition towards green under continental climate conditions like Kazakhstan. In this paper, experimental and theoretical investigations were carried out to develop a pump-based weather in Kazakhstan evaluate its thermodynamic performance. water-to-water system, integrated with exchanger used refrigerant ...

This experimental study investigated narrow and high aspect ratio multi-microchannels that were micro-machined in copper with thin separating walls during saturated flow boiling of refrigerants. The hypothesis was these channels could increase the footprint critical heat flux support future development thermal management systems for power electronics other electronic packages. measured as 678.5...

New copolymers based on vinylidene fluoride (VDF) and 2,3,3,3-tetrafluoroprop-1-ene (1234yf) were synthesized by organometallic-mediated radical copolymerization (OMRcP) using the combination of bis(tert-butylcyclohexyl) peroxydicarbonate initiator bis(acetylacetonato)cobalt(II), (Co(acac)2) as a controlling agent. Kinetics studies fluoroalkenes monitored GPC 19F NMR with molar masses up to 12,...

Growing concerns about the global warming impact of refrigerants used in HVAC&R equipment are driving development and evaluation of alternative refrigerants with lower global warming potentials (GWPs). The Air Conditioning, Heating, and Refrigeration Institute (AHRI) recently coordinated the Low-GWP Alternative Refrigerant Evaluation Program (AREP) in which commercial, university, and governmen...

In this work, a method for the characterization of plate heat exchanger working as evaporator is presented. It based on one-dimensional discretization exchanger, which solves transfer balance equations by means an iterative methodology area converging method. The inputs are flow rates fluids, inlet enthalpy refrigerant, superheating, and temperature pressure secondary fluid. Once refrigerant as...

In this study, the optimum fluid was determined by using Non-dominated Sorting Genetic Algorithm-II (NSGA-II) within scope of Organic Rankine Cycles (ORC) low temperature applications. Heat source temperatures are taken as 90, 100 and 110 °C. Fluid optimization performed comparing performance 8 fluids from 4 different categories under criteria (dry-R601 R601a, isentropic-R141b R123, wet-R152a R...

In this work we analyze numerically different design configurations to be used in a R1234yf DMS cycle coupled with water source, transcritical CO2 heat pump for heating applications the building sector. Specifically, study temperature range proposed by European standard inlet/outlet temperatures of: 30 °C/35 °C, 40 °C/45 47 °C/55 °C and 55 °C/65 °C. Moreover, 25 °C/30 is also analyzed which exp...

This paper presents the design, evaluation, and optimization of an electricity generation system based on two-stage organic Rankine cycle (TS-ORC), which utilizes waste heat existing fluidized bed sewage sludge incineration (FBSSI) facility. The facility incinerates average 300 tons per day with a dry matter content 22%. After drying process, is burned in combustor, exhaust gas at temperature a...

Given the safety issues associated with flammability characteristics of alternative environmentally-friendly refrigerants, it is vital to establish measurement systems accurately analyse these mildly flammable refrigerants. In this study, we used a customised Hartmann bomb analogue measure minimum ignition energy (MIE) and laminar burning velocity (BV) for refrigerant/air mixtures pure ammonia ...