What Are the Three Essential Conditions for the Safe Operation of the Refrigeration System?

2025-01-01

What are the three necessary conditions for the safe operation of the refrigeration system?
Answer:
(1) The refrigerant pressure in the system must not reach an abnormally high level to prevent equipment rupture.
(2) Maloperations such as (possibly leading to) wet stroke, liquid explosion, and liquid hammer must not occur to avoid equipment damage.
(3) Moving parts must not have defects or loose fasteners to prevent mechanical damage.
What is the evaporation temperature?
Answer: The temperature at which the refrigerant in the evaporator boils and vaporizes under a certain pressure is called the evaporation temperature.
What is the condensation temperature?
Answer: The temperature at which the gaseous refrigerant in the condenser condenses into a liquid under a certain pressure is called the condensation temperature.
What is the re - cooling (or sub - cooling) temperature?
Answer:
(1) The temperature at which the liquid refrigerant after condensation is cooled to a temperature lower than the condensation temperature under the condensation pressure is called the re - cooling temperature (or sub - cooling temperature).
What is the intermediate temperature?
Answer:
(1) In a two - stage compression system, the saturated temperature corresponding to the refrigerant in the intermediate cooler under the intermediate pressure is called the intermediate temperature.
How to detect and control the suction temperature of the compressor?
Answer: The suction temperature of the compressor can be measured by a thermometer in front of the suction valve of the compressor.
The suction temperature is generally higher than the evaporation temperature. The difference depends on the length of the return pipe and the pipeline insulation. Generally, it should be 5 - 10 degrees higher than the evaporation temperature. Changing the liquid supply can adjust the degree of superheat.
How to detect the discharge temperature of the compressor, and what factors affect the discharge temperature?
Answer: The discharge temperature of the compressor can be measured by a thermometer on the discharge pipeline. The discharge temperature is proportional to the pressure ratio of (suction and discharge) and the suction temperature.
The higher the suction superheat and the larger the pressure ratio, the higher the discharge temperature; otherwise, it is the opposite. Generally, the discharge pressure is slightly higher than the condensation pressure.
What is floodback (liquid hammer)?
Answer: When the refrigerant fails to absorb heat and evaporate sufficiently, and the refrigerant liquid or wet vapor is sucked into the compressor by the compressor, it is called floodback.