This study compares the performance of five electrical water heater models in the TRNSYS environment. The main capabilities, modeling assumptions and performance of the models are first assessed using an intermodel comparison. The main criteria for comparison are: domestic hot water supply temperature, power demand (time-dependent profile and overall energy use) and vertical temperature distrib...

A simulation model for the CO2 heat pump water heater was developed and validated in this study. Component models of the gas cooler, evaporator, compressor, and expansion valve were constructed with careful consideration for the heat transfer performances. To validate the simulation model, experiments were carried out using an actual CO2 heat pump water heater (water heating capacity: 22.3 kW; ...

This scientific paper gives the main research data obtained during solution of search problem to define optimal parameter values for thermal circuit К-540-23.5 turbine unit that would provide most efficient operation both version high pressure cylinder (HPC) as part and on whole. The effect distribution heat differences in stages flow used by integral quality factors has been assessed. calculat...

The aim of this study is to find the optimal water pressure and percentage of supply vapour in the feed water heaters (fwhs) of steam power plants, such that they maximize the thermal efficiency of the Rankine cycle within pre-specified values of minimum and maximum pressures of the thermodynamic cycle. Thermal efficiency is defined as a function of unknown variables (fluid pressure and vap...

influence of a vent hood at the exit of exhaust flue gas and flue baffles in the firetube on the temperature and flow fields of a gas tank water heater, as well as thestructure and amount of heat transferred to the water tank has been studiednumerically using two-dimensional steady state finite element simulation.observations show that without a vent hood, there is a downward gas flow in theflu...

A significant portion of the energy consumed by home appliances that uses hot water is used for heating cold supply water. Such home appliances generally use supply water at a temperature lower than the ambient temperature. Thus, the water is normally heated from below the ambient temperature to its designed maximum temperature by the appliance, often using natural gas or an electrical heater. ...

We explored repurposing discarded materials to construct simple, field expedient, solar heating devices capable of heating drinking water to water pasteurization temperatures. Results of different test configurations quickly constructed from junk material indicate important design parameters to include maximizing exposed container surface area and using transparent glass and dark absorbent mate...

Many companies in India manufacture solar water heaters but these are not becoming popular in the domestic sector because of their high cost. The Ministry of Non-Conventional Energy Sources (MNES), New Delhi is recommending flat-plate collectors with copper (Cu) risers, headers and plate. Therefore, their cost is high. Long term studies have been carried out at the Central Arid Zone Research In...

Electric water heaters have the ability to store energy in their water buffer without impacting the comfort of the end user. This feature makes them a prime candidate for residential demand response. However, the stochastic and nonlinear dynamics of electric water heaters, makes it challenging to harness their flexibility. Driven by this challenge, this paper formulates the underlying sequentia...

This paper reports the development of a computer approach for evaluating the general performance of stand-alone wind/photovoltaic generating systems. Simple models for different system components are developed, integrated, and used to predict the behavior of generating systems based on available wind/solar and load data. The model is useful for evaluating the performance of stand-alone generati...