Pls help and solve this problem. I don't have an idea to solve this.

A refrigerated space is maintained at -15℃， and cooling water is available at 30℃， the refrigerant is ammonia. The refrigeration

Illusion [34]

Answer:

(1) 5.74

(2) 5.09

(3) 3.05×10⁻⁵ kg/s

(4) 0.00573 kW

Explanation:

The parameters given are;

Working temperature, $T_C$ = -15°C = 258.15 K

Temperature of the cooling water, $T_H$ = 30°C = 303.15 K

(1) The Carnot coefficient of performance is given as follows;

$\gamma_{Max} = \dfrac{T_C}{T_H - T_C} = \dfrac{258.15}{303.15 - 258.15} = 5.74$

(2) For ammonia refrigerant, we have;

$h_2 = h_g = 1466.3 \ kJ/kg$

$h_3 = h_f = 322.42 \ kJ/kg$

$h_4 = h_3 = h_f = 322.42 \ kJ/kg$

s₂ = s₁ = 4.9738 kJ/(kg·K)

0.4538 + x₁ × (5.5397 - 0.4538) = 4.9738

∴ x₁ = (4.9738 - 0.4538)/(5.5397 - 0.4538) = 0.89

$h_1 = h_{f1} + x_1 \times h_{gf}$

h₁ = 111.66 + 0.89 × (1424.6 - 111.66) = 1278.5 kJ/kg

$\gamma = \dfrac{h_1 - h_4}{h_2 - h_1}$

$\gamma = \dfrac{1278.5 - 322.42}{1466.3 - 1278.5} = 5.09$

(3) The circulation rate is given by the mass flow rate, $\dot m$ as follows

$\dot m = \dfrac{Refrigeration \ capacity}{Refrigeration \ effect \ per \ unit \ mass}$

The refrigeration capacity = 105 kJ/h

The refrigeration effect, Q = (h₁ - h₄) = (1278.5 - 322.42) = 956.08 kJ/kg

Therefore;

$\dot m = \dfrac{105}{956.08} = 0.1098 \ kg/h$

$\dot m$ = 0.1098 kg/h = 0.1098/(60*60) = 3.05×10⁻⁵ kg/s

(4) The work done, W = (h₂ - h₁) = (1466.3 - 1278.5) = 187.8 kJ/kg

The rating power = Work done per second = W× $\dot m$

∴ The rating power = 187.8 × 3.05×10⁻⁵ = 0.00573 kW.

6 0

3 years ago

A particular electromagnetic wave travelling in vacuum is detected to have a frequency of 3 × 10 12 Hz. How much time will it ta

irina1246 [14]

3×10^-12 seconds

Explanation:

T=1/f

7 0

2 years ago

LEARNING ACTIVITY SHEET

Nady [450]

Answer:

1. It is used to test/check the continuity of the circuit

a. Ohmmeter

2. Is a physical device used to connect electronic test equipment to a device under test

a. Test probes

3. A device inserted to a convenience outlet to conduct electric current

a. Plug

4. Is a stranded wire used to temporary wiring installation and commonly used in extension cord assembly

a. Duplex cord

5. It is a pocket size tool used to test the line wire or circuit if there is a current in it.

a. Test light

6. An instrument used to measure the amount of electrical current intensity in a circuit

b. Ammeter

7. A pocket sized tool used to test the line wire or circuit if there is current in it.

a. Test light

8. A measuring tool used to measure the length of an object in centimeter in it

b) Ruler

9. It is used to measure the diameter of wires/conductors in circular mills. It can measure small and big sizes of wires

a. Micrometer

10. It is used to measure the voltage, resistance and current of a circuit. It is connected in parallel or series with the circuit depending on what to measure

a) Volt-Ohm-milliammeter

11. It is the measuring tool used to measure length, width and thickness of short object and in sketching straight line

Foot rule/ ruler

Explanation:

1. An Ohmmeter tests resistance of a circuit and therefore, indicates if the circuit has continuity (connectivity) by measuring the resistance to the current it sends through the circuit, while the circuit power is switched off

2. A test probe connects a testing equipment to a Device Under Test (DUT)

3. A plug is used to connect an electric appliance to the mains power supply by fitting it into the mains power outlet

4. A duplex cord is used for temporary wiring to supply power in an extension cord assembly

5. A test light is used to determine if a circuit has electric current flowing in it

6. An ammeter measures the amount of direct or alternating current flowing in a circuit

7. Test light is used to check the presence of an electric current in a circuit

8. A ruler is used to measure length and it is marked in cm or in

9. A micrometer measures the diameter of wires placed in between the anvil and spindle

10. A Volt-Ohm-Milliammeter (VOM), is also known as a multimeter that measures voltage, current, and resistance of a circuit

11. A foot rule/ ruler, measures the dimensions of objects that are flat and short

3 0

3 years ago

If pure oxygen is fed in excess by 25%, what would the fractional conversion of methane be for the final concentration of CO2 in

inessss [21]

Answer:the fractional conversion of methane is 12.5%

Explanation:The reaction represent the combustion of methane to produce Co2 and steam.

CH4 +2O2_CO2 + 2H2O

From gay lussac law of proportionality

1mol of CH4 requires 2mol of Oxygen to produce 1 mol of CO2 and 2mol of H2O

So from the combining ratio,25% of O2 will fractional produce 25×1/2% of CH4.

While 12.5% of CO2 and 25% of steam is also produced .so in essence 2.5% of CO2 was lost in the reaction.

7 0

4 years ago

What should I do I if a patient I’s bleeding th our his penis

Brilliant_brown [7]

Answer:

YOU SHOULD HELP HIM

Explanation:

6 0

3 years ago

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