Coursecode: wb4410A
Coursename: Refrigeration Technology A1

DUT creditpoints: 2
ECTS creditpoints: 3

Subfaculty of Mechanical Engineering and Marine Technology
Lecturer(s): Ree, prof.ir. H. van der, Machielsen, ing. C. H. M., Infante Ferreira, dr. ir. C. A. Tel.: 015-2785362

Catalog data: Historical notes. Ozone and global warming implications. The working field of refrigeration. Overview/comparison of the most important refrigeration systems. Mechanical vapour compression refrigerating machines. Working fluids. Control. Gas cycle refrigerating machines. Thermo-electric cooling. Special refrigerating machines. Vapour absorption refrigerating machines.

 Course year: 4
Period: 0/0/2/2
Hours p/w: 2
Other hours:
Assessment: oral
Assessm.period(s): By app.
(see academic calendar)
Prerequisites: wb1224, wb4200/5, wb4300B, wb4302
Follow up: wb4410B, wb4411
Detailed description of topics:

  • Introduction. Historical notes.

  • Ozone and global warming implications. The Montreal Protocol. Leaktightness requirements. STEK-provisions. ODP, GWP and TEWI.

  • The working field of refrigeration.

  • Overview of the most important refrigeration systems: Mechanical vapour compression refrigerating machines, vapour absorption refrigerating machines, gas cycle refrigerating machines, thermo-electric cooling. Comparison of these systems. Selection criteria.

  • Mechanical vapour compression refrigerating machines. Carnot cycle. Theoretical and actual refrigeration cycles and differences among themselves. The pressure-enthalpy diagram. Entropy production in the components of the refrigeration cycle. Relationship between entropy production and COP. Effect of operating conditions: evaporating temperature, condensing temperature, liquid subcooling, suction vapour superheat and liquid-vapour recuperative heat exchanger. Two-stage operation. Reasons for application. Choice of intermediate pressure. Layout of two-stage systems. Cascade systems. Highlights of components: evaporator, compressor, condenser and expansion devices. Selection criteria.

  • Working fluids. Refrigerants for mechanical vapour compression refrigerating machines: limits of application. Effect of pressure, latent heat of evaporation, safety, price, water, oil, air and high temperature. Media for vapour absorption refrigerating machines: refrigerants and absorbents. Criteria. Media for gas cycle refrigerating machines. Medium for thermo-electric cooling. Secondary coolants.

  • Control. Basic elements of control. Control loops in refrigeration systems. Working principle of correcting unit: on-off, multi-step and continuous control action. Economic evaluation. Model design of refrigerating systems. Physical model. Mathematical model. Model design of correcting unit. SIMULINK model. Control loops for components: compressor, condensor, expansion device, evaporator. Sensors and controllers.

  • Gas cycle refrigerating machines. Gas-phase cycles: Carnot cycle, Brayton cycle, Stirling cycle and Ackeret-Keller cycle. Cycles ending in the liquid-phase: Linde cycle and Claude cycle. Highlights of the components.

  • Thermo-electric cooling. Vortex-tube. Vortex-wheel.

  • Vapour absorption refrigerating machines. COP. Enthalpy-concentration diagram. Theoretical cycle. Actual cycle. Effect of liquid-liquid heat exchanger in the solution circuit, absorption, rectification, evaporation, external heat exchanging, pressure drop and non-condensables. Intermittent operation. Multistage operation and resorption. Highlights of components.
Course material:
  • Stolk, A. L., "Koudetechniek A1", collegedictaat, Faculteit WbMT, TUD, 1990.
  • Infante Ferreira, C. A., "Compressiekoelmachines" en "Regeling", syllabi, 1994.
References from literature:
  • Arora, C. P., "Refrigeration and air conditioning", Tata McGraw-Hill Publishing Company Ltd., New Delhi, 1991.
  • Brodowicz, K. en T. Dyakowski, "Heat pumps", Butterworth-Heinemann Ltd, Oxford, 1993.
  • Cerepnalkovski, I. "Modern refrigerating machines", Elsevier Science Publishers, Amsterdam, 1991.
Remarks (specific information about assesment, entry requirements, etc.):
Goals:
This course aims at giving an overview of and a deeper understanding of the most important refrigerating systems and their sizing-techniques. The knowledge gained in the thermodynamic courses is used to come to evaluation criteria for actual systems. The different systems are discussed using illustrating examples.
Computer use:
Model design of refrigerating systems with SIMULINK.
Laboratory project(s):
Design content:
About 50% of this course deals with discussion of the design methods for the different systems.
Percentage of design: 50%.