A heat exchanger has the objective of condensing 5 kg/s of water vapor and taking it from a pressure of 1.0 MPa and 300 °C to atmospheric pressure and 60 °C. Liquid water is used as refrigerant (Cp= 4.22 kJ/kgK), it enters at 1 °C and leaves the exchanger at 50 °C. a) What is the mass flow rate of the cold water stream? b) If the water is exchanged for another refrigerant substance whose specific heat is 2.0 kJ/kgK, what will be its outlet temperature if the same mass flow is maintained?

Thermodynamics -heat transfer. Show complete work

Present step by step solution. If EB in to be used, start in System Under Study, then, Fluid Under Study, and draw BED.

1. A heat exchanger is located on the roof of a warehouse to heat the air in winter. It is a coil-shaped pipe into which water vapor enters at 0.1 MPa and 300 °C and leaves with a quality of 30%. The warehouse has the following dimensions: 80m x 160m x 10m. The air must be heated from 5°C to 22°C. a. What must be the mass flow rate of the water to heat the air in less than half an hour? b. We want to cool the steam from the exchanger outlet and bring it up to 50 °C. For this, a mixing chamber with water at 20 °C is used, what will be the proportion of the steam mixture? c. The exchanger is damaged and only liquid water can be used at the same pressure (inlet T. 1 °C below saturation and outlet T. at 30°C). How long does it take to heat the air with the same flow of water?

... Moving to another question will save this response. Question 7 Compressed air with a flowrate of 8 kg/min flows through a two-stage turbine and heat exchanger system as follows: • At the entrance to the system (point 1), the pressure of the air is 8 bar and the temperature of the air is 359 K. • From 1-2 the air passes through a heat exchanger which increases its temperature to 922 K. • From 2-3 the air passes through a turbine, with a pressure ratio of 3 (i.e. P₂/p₂=3). This first turbine has an isentropic efficiency of 65%. • From 3-4 the air passes through a second heat exchanger, which increases its temperature back up to 922 K. • From 4-5 the air passes through a second turbine with a pressure ratio of 3 and an isentropic efficiency of 80%. The properties of air are: cp = 1.005 kJ/kgk, cv = 0.718 kJ/kgK, R = 0.287 kJ/kgK, and y= 1.4. Select the correct value for each of the following values: ₂) a. The heat transfer to the air in the first heat exchanger (i.e. ₁) i in kW: b.…

3.24 You want to cool air from 150°C to 60°C but you cannot afford a custom-built heat exchanger. You find a used cross-flow exchanger (both fluids unmixed) in storage. It was previously used to cool 136 kg/min of NH3 vapor from 200°C to 100°C using 320 kg/min of water at 7°C; U was previously 480 W/m²K. How much air can you cool with this exchanger, using the same water supply, if U is approximately unchanged? (Actually, you would have to modify U using the methods of Chapters 6 and 7 once you had the new air flow rate, but that is beyond our present scope.)

Superheated steam at 18 MPa, 560 °C enters the steam turbine. The pressure at the exit of the turbine is 0.06 MPa and saturated liquid water leaves the condenser at 0.06 MPa. Pressure is increased to 18 MPa again after the pump. Find: (a) Sketch the process on a T-s diagram. (b) The net work per unit of steam flow in kJ/kg. (c) Heat transfer to steam passing through the boiler, in kJ/kg.

Homework: A counterflow heat exchanger is located between a collector and a storage tank. The fluid in the collector side is a water-glycol mixture with cp=3840 J/kg. °C and a flow rate of 1.35 kg/s, whereas the fluid in the tank side is water with a flow rate of 0.95 kg/s. If the UA of the heat exchanger is 5650 W/°C, the hot glycol enters the heat exchanger at 59°C, and the water from the tank at 39°C, a) estimate the heat exchange rate; b) if FRUL is 5.71 W/m².°C and collector area is 16 m², what is the ratio FR/FR?

iii) the exit area of the nozzle. Take Cp = 1.005 kJ/kg-K and R=287 J/kg-K Q.B3. A heat engine operates between two reservoirs at 400°C and 30°C. Half the power produced by the heat engine is used to drive a Carnot heat pump that removes heat from the cold surroundings at 2°C and transfers it to a house maintained at 27°C. The heat engine is absorbing heat at a rate of 5 kJ/s. i) Draw the complete schematic of the device ii) Determine the thermal efficiency of the heat engine iii) Determine the coefficient of performance of the heat pump iv) Determine the rate of heat loss from the house. v) Determine the minimum rate of heat extraction by the heat pump, and vi) the total rate of heat rejection.