1. BAE4400 Topics in Processing
Fall 2006
August 22 through September 21
1 hour credit
Dr. C. L. Jones
Biosystems and Ag. Engineering

2. Refrigeration – Lecture 2
Assignment:
Read Chapter 11 in Henderson/Perry
HW #5 Due 9/19/06, graded papers will be in your mailboxes in 208 on 9/20
Psychrometrics quiz 9/19/06, in boxes on 9/20
Final 9/21/06
GO TO THE CAREER FAIRS!!!!!
Dr. C. L. Jones
Biosystems and Ag. Engineering

3. Dr. C. L. Jones
Biosystems and Ag. Engineering

4. System Design: Evaporator
The lower the evaporator temperature, the lower the low-side-pressure required and a compressor with greater vol. capacity is required.
Determining refrigerant mass flow rate: Example 11.2 pg 340
Dr. C. L. Jones
Biosystems and Ag. Engineering

5. System Design: Compressor
Equation pg. 341
Compressor displacement = DNS
Required compressor power per unit of refrigeration:
Equation pg 341
Dr. C. L. Jones
Biosystems and Ag. Engineering

6. Examples: Refrigeration system with the following specs: Find:
Requires 15 kw
Uses R134a for refrigerant
Evaporator Temp = -18C
Condenser is watercooled w/ 22C water
Compressor vol. eff = 83%, thermal eff = 89%
Find:
A) high and low side pressures
B) compressor displacement
C) compressor power per unit of refrigeration required
D) Refrigerant rate
E) COPcooling
Dr. C. L. Jones
Biosystems and Ag. Engineering

7. Examples: Refrigeration system with the following specs: Find:
Requires 15 kw
Uses R134a for refrigerant Ammonia
Evaporator Temp = -18C
Condenser is watercooled w/ 22C water
Compressor vol. eff = 83%, thermal eff = 89%
Find:
A) high and low side pressures
B) compressor displacement
C) compressor power per unit of refrigeration required
D) Refrigerant rate
E) COPcooling
Dr. C. L. Jones
Biosystems and Ag. Engineering