What is Refrigeration cooling?

Refrigeration refers to the use of artificial methods to cool an object or fluid in a certain time and a certain space, so that its temperature is lower than the ambient temperature, and to maintain this temperature.


Geson chiller is one of the leading China refrigeration cooling system manufacturers, focuses on Industrial and Commercial Refrigeration Units and Refrigeration Systems Products.

Supply Industrial Process Cooling Solutions, and Commercial HVAC Solutions.

All Types of Water Chillers:

Water-cooled Chiller

Water-cooled Screw Chiller

Air-cooled Screw Chiller

Air-cooled Scroll Chiller

Water Scroll Chiller

Modular Chiller

Mini Chiller

Air Source Heat Pump

Swimming Pool Heat Pump

Water Source Heat Pump

Water Tower


Capacity from 2 Tons to 4000 Tons, and Temperature From -160℃~30℃, Complete Full Water Chiller Product Series

Temperature Definition:

  • In the legal unit of measurement, thermodynamic temperature is used.

And allow the Celsius temperature to be used at the same time.

The thermodynamic temperature symbol is represented by T,

and the unit symbol is K.

Celsius (metric) and Fahrenheit (imperial) are still used in engineering.

Celsius temperature is expressed by t, and the unit symbol is ℃;


  • Fahrenheit temperature is expressed by θ, and the unit symbol is ℉.

GESON water chiller products from Capacity from 2 Tons to 4000 Tons, and Temperature From -160℃~30℃, Complete Full Water Chiller Systems.

Contact Us and Tell us what temperature you need for your process cooling.

We will offer you the right refrigeration and cooling water chiller model selections.

Gasification Definition:

The process of changing a substance from liquid to gas is called gasification.

There are two different ways of gasification:

Evaporation and boiling.

Evaporation refers to the process,

In which molecules on the surface of a liquid,

evaporate into vapor molecules at any temperature.

Evaporation can occur at any pressure

and at any temperature.

Boiling is a process, in which many small vapor bubbles are formed inside the liquid, under a certain temperature and pressure,

and they rise rapidly, break through the surface of the liquid and burst into gas.

Therefore, boiling is a phenomenon of violent vaporization on the surface,

and inside of the liquid at the same time.

The temperature at which the liquid is boiling is called the boiling point.

The liquid must absorb heat during the boiling process and keep its humidity constant.

To make the boiling process continue, heat must be continuously added from the outside.

Enthalpy Definition:

Enthalpy is a state parameter,

which is equal to the sum of the system’s thermodynamic energy, and compression work in value.

The symbol for enthalpy is H,

and the unit is J


In the formula, U-internal energy (J),

P-pressure (Pa);

V-volume (m3).

Obviously P, V and U are all state parameters,

So H is also a state parameter.


  • The Specific Enthalpy (mass enthalpy) is commonly used in the analysis,

and calculation of refrigeration systems.

Specific Enthalpy is enthalpy divided by mass,

the symbol is h, and the unit is J/kg


Latent heat definition:

Latent heat refers to what is absorbed or released,

when a substance undergoes a phase change,

and the temperature does not change


Generally, latent heat is much larger than sensible heat.

  • In the refrigeration cycle,

it is the use of the refrigerant to absorb the latent heat of vaporization,

from the surrounding objects or space,

when the refrigerant changes from liquid to vapor.

So as to achieve refrigeration.


The vaporization process of the refrigerant in the evaporator is a boiling process,

but people are accustomed to calling it an evaporation process.

  • The process of changing a substance from a gaseous state to a liquid state is called condensation.

Because the condensation process releases the latent heat of vaporization,

it is usually called condensation.


GESON close type counter flow cooling water tower is designed by the latent heat. GESON cooling tower is a high efficiency cooling tower.

Bubble point temperature, Dew point temperature

  • Under certain pressure,

when the solution is heated,

it first reaches the saturated liquid point.

At this time, the corresponding state is the bubble point,

and its temperature is called the bubble point temperature.

  • On the basis of the bubble point state,

continue to heat the solution until all of it has evaporated, which is called saturated vapor.

At this time, the corresponding state is the dew point,

and its temperature is called the dew point temperature.

Specific heat capacity (specific heat)

The calculation and analysis of the heat absorbed or released by the working method.

in the thermal process often involves the specific heat capacity of the working method,

which is one of the important thermal properties of the working method.

  • The amount of heat required for a unit mass of material,

to increase its temperature by 1°C,

is called the specific heat capacity of the material,

represented by the symbol C,

and the unit is J/(kg·k) or kJ/(kg·k)

First law of thermodynamics

First law of thermodynamics

The first law of thermodynamics is the application in energy conversion with thermal phenomena.

Is the law of conservation of energy and conversion,

The first law of thermodynamics states:

All matter in nature has energy.

It can be transformed from one form to another,

and transferred from one object to another.

The total amount of energy remains unchanged during the conversion and transmission.

For any system, the first law of thermodynamics can generally be expressed as:

Energy entering the system-energy leaving the system = energy change in the system

The second law of thermodynamics

The second law of thermodynamics can be expressed as:

All mechanical energy can be converted into heat,

but heat cannot be converted into mechanical work unconditionally.

It can be seen that,

the use of a heat source (or cold source) cannot complete the cycle process,

nor can it achieve continuous conversion of energy.

It is impossible to transfer heat from a low-temperature object to a high-temperature object,

without causing other changes.

It shows that the heat transfer from a low-temperature object to a high-temperature object cannot be carried out spontaneously.

To achieve it, a certain “cost” or certain “conditions” (or other changes) must be spent in order to achieve.

In a refrigerator or heat pump,

The cost is the amount of work or heat consumed.

On the contrary,

the heat transfer from the high-temperature object to the low-temperature object can proceed spontaneously

until the two objects reach thermal equilibrium.

Forward cycle (heating engine principle)

Reverse cycle (refrigeration, heat pump principle)


Common pressure types and conversion relationships

Pa mmHg Standard Atmospheric Pressure
(N/m2) (kgf/cm2) Psi


(bar) (mm.Hg)


1 0.102×10-4 0.145×10-3 10-5 7.5×10-3 0.987×10-5
98.07×103 1 14.22 0.9807 735.6 0.9678
6895 0.0703 1 0.06895 51.72 0.068
105 1.02 14.5 1 750.1 0.987
133.3 1.36×10-3 0.0193 1.333×10-3 1 1.31×10-3
1.013×105 1.033 14.7 1.013 760 1

Common power units and conversion relations:

KW Horsepower kcal/hr British thermal Btu/hr RT
(kW) (HP) (kcal/hr) (Btu/hr) Japanese  RT American  RT British RT
1 1.36 860 3412.1 0.259 0.2844 0.2549
0.735 1 632 2510 0.1931 0.2121 0.1901
1.16×10-3 1.583×10-3 1 3.968 3.012×10-4 3.307×10-4 2.964×10-4
2.931×10-4 3.986×10-4 0.252 1 7.591×10-5 8.335×10-5 7.471×10-5
3.861 5.251 3320 13174 1 1.098 0.9841
3.517 4.783 3024 12000 0.9108 1 0.9864
3.923 5.335 3373 13384 1.016 1.112 1


Common units and conversion

Celsius and Fahrenheit



Absolute pressure = Gauge pressure + Atmospheric pressure





1RT (United States)=3024kcal/h=3.516kw

Welcome to visit our website: www.gesonchiller.com, and tell us your requirements and your industry cooling need.

You can visit the following industrial water chiller from GESON:

Process Chiller

Industrial Water Chiller

Plastic Industrial Chiller

Injection Molding Chiller

Blowing Molding Chiller

Extrusion Machinery Chiller

Metal Working Cutting Oils Chiller

Welding Equipment Chiller

Chemical Processing Chiller

Pharmaceutical Formulation Chiller

Food and Dairy Chiller

Beverage Processing and Glycol Beer Chiller

Vacuum Systems Chiller

Compressed Air and Gas Chiller

MRI and Laser Chiller

Computer Data Center Chiller

Beer and Wine Fermentation Chiller

Ice Rink Chiller

Marine Chiller

Lab Chiller