A gas fired single-effect LiBr-H2O absorption refrigeration system as shown in Figure-2(a), operates with an evaporator temperature of 10 °C and condenser temperature of 42 °C. The mass flow rate of the solution delivered by the pump is 0.70 kg/s and the concentrations of the weak and strong
solutions are 52% and 66% by mass, respectively.
(a) Determine the mass flow rates of the solution returning from the generator to the absorber and the mass flow rates of the refrigerant through the system.
(b) If the generator is operating at 100 °C and the absorber at 35 °C, determine, with the aid of the diagrams and tables provided, the rates of heat transfer in the following
components:
1. Generator
ii. Absorber
iii. Condenser
iv. Evaporator
(c) If the system is modified by connecting the solution heat exchanger shown Figure-2(b), the condensing temperature drops by 2 K and the temperature entering the generator from the absorber increases by 15 K. Whilst maintaining the same
generator operating temperature;
1. Determine the concentrations for the strong solution? Determine the new rate of heat transfer at the absorber and the solution
temperature at the entry of the absorber from the generator?
Determine the real coefficient of performance?
iv. Determine if there is a risk of crystallisation?
(c) Give four benefits of a single effect H2O-LiBr absorption cooling system in comparison with a conventional vapour compression cooling system of an equivalent cooling output.
- A Gas Fired Single Effect Libr H2o Absorption Refrigeration System As Shown In Figure 2 A Operates With An Evaporator 1 (168.36 KiB) Viewed 11 times
Question 2 A gas fired single-effect LiBr-H20 absorption refrigeration system as shown in Figure-2(a), operates with an evaporator temperature of 10 °C and condenser temperature of 42 °C. The mass flow rate of the solution delivered by the pump is 0.70 kg/s and the concentrations of the weak and strong
solutions are 52% and 66% by mass, respectively 3 Condenser Generator 7 5 52 66% 8 X +6 Absorber Evaporator Figure-2(a) Schematic diagram of a single effect LiBr-H20 absorption refrigeration cycle (a) Determine the mass flow rates of the solution returning from the generator to the absorber and the mass flow rates of the refrigerant through the system. (b) If the generator is operating at 100 °C and the absorber at 35 °C, determine, with the aid of the diagrams and tables provided, the rates of heat transfer in the following components: i. Generator Absorber iii. Condenser iv. Evaporator ii. (c) If the system is modified by connecting the solution heat exchanger shown in Figure-2(b), the condensing temperature drops by 2 K and the temperature entering the generator from the absorber increases by 15 K. Whilst maintaining the same generator operating temperature; i. Determine the concentrations for the strong solution? ii. Determine the new rate of heat transfer at the absorber and the solution temperature at the entry of the absorber from the generator? Determine the real coefficient of performance? Determine if there is a risk of crystallisation? dA Solution heat exchanger (SHX) iii. iv. bV с Figure-2(b), Solution heat exchanger (c) Give four benefits of a single effect H2O-LiBr absorption cooling system in comparison with a conventional vapour compression cooling system of an equivalent cooling output.