Recent developments in the industrial refrigeration, air conditioning and heat pump sector have included significant increases in the typical operating pressures of systems. With ammonia this offers several opportunities to capitalise on the high critical temperature and high index of compression of the refrigerant in order to deliver heat efficiently in the temperature range 70C – 90C. It also...

This communication presents finite time thermodynamic optimization of irreversible cascaded refrigeration and heat pump cycles having source/sink thermal reservoirs of finite heat capacitance. A general expression for the optimum coefficient of performance of the refrigerator/heat pump is derived at minimum power input and given cooling/heating load conditions, respectively. External irreversib...

Accurate modeling of heat dissipation in pediatric intracorporeal devices is crucial in avoiding tissue and blood thermotrauma. Thermal models of new Maglev ventricular assist device (VAD) concepts for the PediaFlow VAD are developed by incorporating empirical heat transfer equations with thermal finite element analysis (FEA). The models assume three main sources of waste heat generation: coppe...

In this paper, an economic study of solar heat pumps and an investigation of differences between solar heat pumps and conventional heat pumps—based on their performances and energy consumption—are conducted for a residential apartment located in Austin, Texas, USA. Heating in the apartment is provided via a solar heat pump during the cold months of a year. Solar collectors are used to meet the ...

Confined aquifers are formations surrounded by impermeable layers called cap rocks and bed rocks. These aquifers are suitable for the seasonal storage of thermal energy. A confined aquifer was designed to meet the cooling and heating energy needs of a residential building complex located in Tehran, Iran. The annual cooling and heating energy needs of the buildings were estimated to be 8.7...

no published information are available on the reproductive indices of local abadeh does reared innorthern fars province, southern iran. this study was conducted to determine the duration of the breedingseason, and the length and duration of the oestrous cycle. twenty single parity 2-year-old does from abadeh(weighing 19–26 kg) were purchased and transferred to the school of veterinary medicine ...

The data reported in this article presents actual installation costs and performance data for a selection of residential Ground Source Heat Pump (GSHP) systems in Melbourne, Australia. The installation cost data includes five main cost components: ground loop installation, head pipe installation, heat pump, mechanical room installation, and fittings. The performance data presented here includes...

Introduction Jet pumps are static components that can be used in closed-loop, traveling wave thermoacoustic devices to suppress a time-averaged mass flux (Gedeon streaming) that can exist [2]. The minimization of convective heat transport caused by this mass flux is of vital importance due to the detrimental effect it has on the device’s efficiency. Jet pumps have an asymmetric shape, resulting...

This paper introduces the concept of installing a small-scale organic Rankine cycle system for the generation of electricity in remote areas of developing countries. The Organic Rankine Cycle Systems (ORC) system uses a commercial magnetically-coupled scroll expander, plate type heat exchangers and plunger type working fluid feed pump. The heat source for the ORC system can be solar energy. A s...