How do you calculate mass flow rate of refrigerant?

How do you calculate mass flow rate of refrigerant?

Basic Calculations

1. Refrigerant mass flow rate (kg/s) (9.6) r = Q e / h 1 − h 4.
2. Compressor isentropic power (kW) (9.8) r h 2 − h 1.
3. Heat rejected in condenser (kW) (9.9) h 2 − h 3.

What is mass flow rate in refrigeration?

Saturated vapor enters the compressor. at − 10°C and saturated liquid leaves the condenser at 9 bar. The mass flow rate of the. refrigerant is 0.08 kg/s.

How do you calculate mass flow on a compressor?

A units check gives area x length/time x time = area x length = volume. The mass m contained in this volume is simply density r times the volume. To determine the mass flow rate mdot, we divide the mass by the time. The resulting definition of mass flow rate is shown on the slide in red.

What is the formula for finding mass flow rate in a water cooled condenser?

Using the equations, UA/(mccpc) = (Tc2- Tc1)/LMTD and UA/(mhcph) = (Th1- Th2)/LMTD , where A is surface area, 3.1417 do L , mc mh, cpc, cph are mass flow rates and specific heats of cold and hot fluids 9determined by temperatures of fluid at bulk temperatures from data book, mass flow rates can be determined.

How does mass flow rate affect heat transfer?

The heat transfer coefficient decreases by ˜10% with a threefold increase in the mass flow rate under these conditions, based on the commonly used Dittus-Boelter correlation for estimation of the heat transfer coefficient. Doubling the mass flow rate will result in a 92% increase in the heat transfer coefficient.

How do you calculate heat flow rate?

Calculate the rate of heat flow (in J/s = Watts) by conduction through a glass window 2.0 m multiplied by 3 m in area and 4 mm thick, if the inside temperature is 15o C and the outside temperature is -5o C. ΔQ/Δt = -kA*(T2 – T1)/Δx. Details of the calculation: Let the inside be side 2 and the outside be side 1.

What is heat loss rate?

Heat loss is the decrease of heat existing in space, resulting from heat transfer through walls, roof, windows and buildings surfaces. We calculate heat loss by multiplying the values of the area, the difference in temperatures of inside and outside surfaces and the value of heat loss of the material.

What are the 4 methods of heat loss?

Topic Overview

• Evaporation of water from your skin if it is wet (sweating).
• Radiation (similar to heat leaving a woodstove).
• Conduction (such as heat loss from sleeping on the cold ground).
• Convection (similar to sitting in front of a fan or having the wind blow on you).

What is the formula of heat loss?

The general heat loss formula is: Q=U*A*ΔT, or in plain words, the heat loss of an area of size A is determined by the U value of the materials and the difference in temperature between inside and out (that is the difference in temperature of the two surfaces, not the two air temperatures, which might not be quite the …

How do you calculate heat gain and loss?

The formula used to calculate heat gain from thermal conduction (outside ambient temperature during the cooling season) is the same basic formula as the Heat Loss Formula, [(Square Foot Area) x (U-Value) x (Temperature Difference)].

What is heat load estimation?

Heat sources which result in an internal heat like heat conduction through the glass, walls, etc. Heat sources which result in an external heat load, heat from any source added in the air after it leaves a space. The heat load formula is given as, Heat load = Q = m × Cp ×ΔT.

What are the effects of heat gain and heat loss?

When a liquid loses heat, it freezes to become a solid. When solid ice at 0°C is heated, it gains heat and melts to form liquid water. When a gas loses heat, it condenses to form liquid water. When a liquid gains heat, it evaporates to form a gas.

What is heat gained by a body?

a rise in temperature of a body when obtaining heat by radiation or conduction from an outside source, leading to an increase in METABOLIC RATE in all organs. see TEMPERATURE REGULATION.

What should your core temperature be?

The average body temperature is 98.6°F (37°C). But you should know that “normal core body temperature” varies slightly from person to person. It’s not a specific number but rather a range of what’s thought to be healthy. Any temperature from 97°F (36.1°C) and 99°F (37.2°C) can be considered normal.

How many watts does it take to heat water?

A typical 50-gallon electric tank runs at 4500 watts. From above, heating a gallon of water by 1 F takes 8.33 BTU. Heating from 68 F to 104 F would by a 36 F rise, or 36 x 8.33 = 300 BTU to heat 1 gallon of water.

How hot is 1000 watts?

700 Watts in microwave >> like cooking at 350 degrees 800 Watts >> 450 degrees 900 Watts >> 525 degrees (Self clean) 1000 Watts >> 575 degrees 1100 Watts >> 625 degrees (Blow torch!!)

How many watts does it take to heat 1 Litre of water?

24 calorie per second. It takes 1000 calories to raise 1 liter of water one degree C. So apply about 4000 watts for one second to do this.

How do you calculate the energy required to heat water?

The specific heat capacity of water is 4.18 J/g/°C. We wish to determine the value of Q – the quantity of heat. To do so, we would use the equation Q = m•C•ΔT. The m and the C are known; the ΔT can be determined from the initial and final temperature.

How much energy does it take to heat 1 degree of water?

The specific heat capacity of water is 4,200 Joules per kilogram per degree Celsius (J/kg°C). This means that it takes 4,200 J to raise the temperature of 1 kg of water by 1°C.

How many kWh does it take to boil 1 Litre of water?

0.183 kWh

What is the most efficient way to boil water?

An electric teakettle is about 80 percent efficient, although again this varies from kettle to kettle. Electric kettles are generally very well insulated, and the heating coils sit directly in the water, so less heat is lost to the air. An induction stove or hot plate is about 85 percent efficient.

How many joules does it take to boil 1 Litre of water?

So 0 degrees C is 273 degrees Kelvin. What c in the equation is, the specific heat capacity. So in water it takes 1200 joule’s to raise a Kg of water by 1 degree K or in degrees C. If this takes 1 min to boil the power required to boil the water equals 96kilo joules/60 seconds =1600 watts or 1.6 kilo watts.

What type of energy transfer is boiling water?

1 Expert Answer. Conduction. The stove heats up the pot or kettle the water is in. The heat energy is transferred to the water.

What type of energy is used to boil water?

1 Answer. Boiling water is an endothermic process, which supplies heat to the water molecules, increasing their potential energy. The applied heat causes the water molecules to move further away from each other without causing any increase in overall temperature.

Why does it take so much energy to boil water?

Explanation: In order to cause water to increase in temperature, the energy being put into the water first needs to break hydrogen bonds between the water molecules. Hydrogen bonding in water is significant, so it takes a significant amount of energy to overcome them.