Auxiliary accessories commonly used in low-temperature chillers, including water flow switch, pressure controller, differential pressure controller, temperature controller and solenoid valve, as well as a brief introduction to three types of refrigeration, liquid vaporization refrigeration, gas expansion refrigeration and thermoelectric refrigeration.

I. Auxiliary accessories commonly used in low-temperature chiller units

1、Water flow switch

Water flow switch is used to control or cut off the flow of fluid in the pipeline for protection. When the fluid flow reaches the regulated value, the switch automatically cuts off (or turns on) the circuit.

2、Pressure controller

The pressure controller is used for pressure control and pressure protection. The chiller has low pressure and high pressure controllers, which are used to control the working range of the pressure of the system.

3、Differential pressure controller

The differential pressure controller is used to control the differential pressure. When the differential pressure reaches the adjustment value, the switch will automatically cut off (or turn on) the circuit.

4、Temperature controller

The temperature controller is used for the control or protection of the unit, and the switch will automatically cut off (or turn on) the circuit when the temperature reaches the set value. In our products, the temperature control is often used to control the start and stop of the unit with the water tank temperature. There are also some like antifreeze need to use the temperature controller.

5、Solenoid valve

Cut off the system circuit when the compressor stops, to avoid the next start of the press when the liquid shock, generally used in the larger refrigeration system.

Two, three types of refrigeration

1、Liquid gasification refrigeration:

(1) compression: room temperature gaseous state into high pressure high temperature gaseous state.

(2) condensation: high-pressure high-temperature gaseous state into high-pressure liquid state.

(3) evaporation: high-pressure liquid state into a low-pressure gas state, heat absorption, to achieve refrigeration.

2、Gas expansion refrigeration:

Gas expansion refrigeration is the use of high-pressure gas adiabatic expansion to achieve low temperature, and the use of expansion of the gas in the low-pressure reheat process to refrigeration, due to the different equipment for gas adiabatic expansion, there are generally two ways: one is to expand the high-pressure gas by the expander, there is external power output, and thus the temperature drop of the gas is large, the reheat refrigeration capacity is also large, but the expander structure is more complex, the other way is to make the gas by The other way is to expand the gas through the throttle valve without external power output, the temperature drop of the gas is small, and the cooling capacity is also small, but the structure of the throttle valve is relatively simple, and it is easy to adjust the gas flow.