5.75 A heating system must maintain the interior of a building at TH = 20 degree C when the outside temperature is T =...
6. An office building requires a heat transfer rate of 20 kW to maintain the inside temperature at 21°C when the outside temperature is 0°C. A vapor-compression heat pump with Refrigerant 134a as the working fluid is to be used to provide the necessary heating. The compressor operates adiabatically with an isentropic efficiency of 82%. Specify appropriate evaporator and condenser pressures of a cycle for this purpose assuming Δ1cond-Al evap-10°C, as shown below. The states are numbered as shown below....
US PRINTER VERSİON "ACKIC I Problem 5.044 SI A heat pump cycle is used to maintain the intenior of a building at 20°C. At steady state, the heat pump receives energy by 9eC and discharges energy by heat transfer to the building at a rate of 120,000 k/h. Over a period of 14 days, an electric meter records that 2000 kw-h of electricity is provided to the heat pump. Determine: (a) the amount of eneroy that the heat pump receives...
On a cold winter day, the outside temperature is -20°C and the inside temperature is maintained at 20°C. There is a net heat flow to the outside through the walls, roof, etc., of 25 kW. What is the rate of increase of the entropy of the universe as a result of this heat flow?
2. A heat pump is operated to maintain a home at 25 °C when the outside temperature is only -5 °C. (a) If the house requires 50 kW heat, what is the power required for the heat pump? Assume the heat pump to be a Carnot heat pump (b) If an electric heater was used for this purpose instead, assuming an electric current of 5A, what would be the required resistance of the heater? (c) If electricity costs 10 cents...
5, (25 points) A Carnot heat pump is used to maintain a house at 20 °C in winter and consumes 8 kW of power (electricity) when operating. On a day temperature outside the house is -3 °C, the house is estimated to lose heat at an average rate of 80,000 kJ/h. (Sa). (2p) Please identify the hot reservoir and the cool reservoir of this heat pump. (5b). (2p) Please draw of schematic diagram of this heat pump-house heating system with...
In a vapor-compression refrigeration heat pump cycle with Refrigerant 134a as the working fluid provides heating at a rate of 15 kW to maintain a building at 20 °C year-round. During the heating mode in the winter, the outside temperature is 5 °C. It is also used for cooling in the summer when outside temperature is 34 °C. Saturated vapor at 2.4 bar leaves the evaporator and superheated vapor at 8 bar leaves the compressor. There is no significant heat...
In a vapor-compression refrigeration heat pump cycle with Refrigerant 134a as the working fluid provides heating at a rate of 15 kW to maintain a building at 20 °C year-round. During the heating mode in the winter, the outside temperature is 5 °C. It is also used for cooling in the summer when outside temperature is 34 °C. Saturated vapor at 2.4 bar leaves the evaporator and superheated vapor at 8 bar leaves the compressor. There is no significant heat...
In a vapor-compression refrigeration heat pump cycle with Refrigerant 134a as the working fluid provides heating at a rate of 15 kW to maintain a building at 20 °C year-round. During the heating mode in the winter, the outside temperature is 5 °C. It is also used for cooling in the summer when outside temperature is 34°C. Saturated vapor at 2.4 bar leaves the evaporator and superheated vapor at 8 bar leaves the compressor. There is no significant heat transfer...
In this problem you will estimate the heat lost by a typical house, assuming that the temperature inside is T(in) = 20 degrees celcius and the temperature outside is T(out) = 0 degrees celcius. The walls have fiberglass insulation, which dominates the heat conduction properties of the wall So we can consider the wall to have a thermal conductivity of k(wall) = 0.048 W/m/K . We will take the thickness of the walls and ceiling to be L(wall) = 12...
Homework 7 heat transfer 2018-20 1) A horizontal tube of 12.5-mm dimeter with an outer srface temperature of 240°C is placed in a room with an air temperature of 20°C. Estimate the heat transfer rate per unit length of the tube due to free convection. 2) Air at -10°C flows at 10 m/s over the roof plate of two 5m length rooms whose air is at Too-200C. The roof plate is 0.20-m thick concrete (k = 0.6 w/ m. K)....