RU33807U1 - Refrigeration unit - Google Patents

Description

The utility model relates to the field of refrigeration and can be used in the design and reconstruction of large refrigeration units.

Known refrigeration units containing a compressor, a water condenser, an evaporator, an air condenser, adjusting devices and locking screws 1.

Closest to the claimed utility model is the device described in the Method of operation of the refrigeration unit.

The prototype refrigeration unit consists of a compressor, an evaporator, air and liquid cooling condensers, throttle and shut-off valves, a separation chamber, a liquid separator and irrigated nozzles.

The disadvantages of the known refrigeration units are the large economic costs when operating the refrigeration unit in the winter at ambient temperature; its air is cooler below the temperature; it is cooled.

The objective of this technical solution is to increase the efficiency of the refrigeration unit in winter at an ambient temperature below the temperature of the coolant, and increase

refrigeration capacity of a refrigeration unit at various temperatures of outdoor air and coolant.

The task is achieved in that the refrigeration unit contains a compressor and, installed along the refrigerant, an air-cooled condenser, a liquid-cooled condenser, throttle valves, an evaporator, a separation chamber, a liquid separator, irrigated nozzles and shut-off valves, in addition, the refrigeration unit additionally contains a compressor and the evaporator, and to toi, where

to is the boiling point of the refrigerant in the additional evaporator;

toi is the boiling point of the refrigerant in the evaporator.

The proposed refrigeration unit is shown in Figure 1. The refrigeration unit contains two compressors with high 1 and low 2 refrigerant vapor compression temperatures and installed along the refrigerant, air-cooled condenser 3, liquid-cooled condenser 4, throttle valves 8.11, separation chamber 7, liquid separator 9, irrigated nozzles 10, evaporators with high 5 and low 6 refrigerant boiling points and shut-off valves 12-25, and the air-cooled condenser 3 should be located above the evaporator leu 5 and 6 to a height less than the height of the column of liquid refrigerant that allows overcoming hydraulic resistance to movement refrigerant evaporator circuit capacitor (3-5) and (5-6).

Before starting the work of the refrigeration unit, the total Ш1osh is determined; ad the surface of the air-cooled condenser, which is selected from the condition Qk Qo, then using formula 3 determine:

FK (1), where

Qk — capacitor working load, W; QO - cooling capacity, W;

FK is the total surface of the air-cooled condenser, k is the heat transfer coefficient, referred to the external heat-exchange surface, W / (); k (30 ... 45) W / (); 0k is the average logarithmic temperature difference in the air-cooled condenser, ° С.

ek tB2-tBl / ln (tK-tB, / tK-tB2) (2), where

IK - refrigerant condensation temperature, ° С; tpi - air temperature to the condenser, ° С; 1v2 - air temperature after the condenser, ° С.

To ensure the production of cold at a higher boiling point of the evaporator by naturally chilling the refrigerant during the winter period, it is assumed that the calculated outdoor temperature (tsi) is (5-7) ° C lower than the boiling point of the evaporator by a higher cold parameter. By the formulas 3, the surfaces of the air and liquid cooling condensers are calculated. FKBO QKBO /, where

QKBO QO (in C) ek tB2-tBl / ln (tK-tBl / tK-tB2), where

tBi V (5-7) ° С

IK to where

QKBO - operating load on the air-cooled condenser calculated over the winter period, W; QO - cooling capacity, W; FKBO - common surface of the air-cooled condenser,

k is the heat transfer coefficient that is not relevant to the outdoor

heat exchange surface, W / (); k (30 ... 45) W / ();

Ok is the average logarithmic temperature difference in the capacitor

air cooling in the winter, ° C;

 - maximum boiling point, ° C;

.- condensation temperature of the refrigerant in the winter, ° C;

1v1 - air temperature to the condenser, ° С;

1v2 - air temperature after the condenser, ° С.

Next, determine the total load on the condensers of air and liquid cooling.

/ total Q l-D VKVKBO h; liquid -)

О О ° - О (liquid VKVKBO)

QKBO (5), where

ek tB2-tBi / ln (t / -tBi / tK -tB2)

IB - calculated summer air temperature to the condenser, ° С;

t / is the condensation temperature of the refrigerant in the summer, ° C;

1v2 - air temperature after the condenser, ° С;

QKBO - load on air-cooled condenser

calculated by the summer period, W;

Rzhid - load on the condenser of liquid cooling

calculated for the summer period, Tue

The refrigeration unit can operate in several modes: l) where

tnB- outdoor temperature, ° С;

1ozh - coolant temperature, ° С. 2) toi (-7 ° C) where

toi is the boiling point of the liquid refrigerant, ° C; IHB- outdoor temperature, ° C;

1ozh - coolant temperature, ° С. 3) 1nv toi (-7 ° C), where

1nv - outdoor temperature, ° С;

 Y /

-, -G

toi is the boiling point of the liquid refrigerant, ° C.

The operation of the refrigeration unit in the 1nv to: mode is as follows.

Compressors 1 and 2 draw in refrigerant vapor from evaporators 5 and 6, pump them into the air-cooled condenser 3, while the shut-off valve 13 is open and the shut-off valve 14 is closed. The partially condensed refrigerant enters the liquid-cooled condenser 4, wherein the shut-off valve 15 is open and the shut-off valve 25 is closed. Then, the condensed refrigerant through the open shut-off valves 16,18,19 is throttled in the throttle valves 11 and enters the evaporators 5 and 6. Part of the condensed refrigerant through the open valve 21 through the liquid circuit from the air-cooled condenser 3 enters the evaporator 5. Then the cycle is repeated.

The operation of the refrigeration unit in the toi (-7 ° C) IHB W mode is as follows.

The refrigerant vapor compressed in the compressors 1 and 2 enters the liquid cooling condenser 4 through the open shut-off valve 14, while the shut-off valve 13 is closed. After this condenser, the partially condensed refrigerant through the shut-off valve 17 is divided into two flows in the separation chamber 7, while the shut-off valve 16 is closed. The liquid and gaseous flows formed in the separation chamber 7 are throttled in the throttle valves 8 to an intermediate pressure, which is equal to the condensation pressure in the condenser 3

air cooling. After that, notes are fed into the liquid space of the liquid separator 9. Passing through the liquid refrigerant layer and irrigated by liquid refrigerant from the air-cooled condenser 3 of the nozzle 10, the refrigerant vapor constituting the gas stream partially condenses and enters the air-cooled condenser 3 through the open shut-off valve 24. From this condenser, the liquid refrigerant through the open shut-off valve 25 is supplied to the liquid separator 9, the valve 15 is closed. The supercooled refrigerant through the open shut-off valves 18-20 from the liquid separator 9 through the throttle valves 11 enters the evaporators 5 and 6. At the same time, through the open valves 22.23, the gaseous stream from the air-cooled condenser 3 is directed to the suction line to compressor 1. Next, the cycle repeated.

The operation of the refrigeration unit in 1nv toi mode (-7 ° C) is carried out with one working compressor 1 in a closed loop.

Compressed 1 refrigerant vapor in the compressor through open shut-off valves 12 and 13 enters the air-cooled condenser 3, while valve 14 is closed. The partially condensed refrigerant through the open valve 21 enters the evaporator 5, while the valves 15 and 25 are closed, and the formed gaseous refrigerant in the condenser 3 through the open valve 23 enters the suction in the compressor 1. Then the cycle is repeated.

Thus, at different values of the temperature of the outside air, the temperature of the coolant and the boiling point of the refrigerant in the evaporators, the refrigeration unit operates in a different sequence, and for each case in

separately. Two additional self-circulation circuits provide a more reliable and economical operation of the installation, since the liquid goes directly from the air-cooled condenser to the evaporator with a higher boiling point of the refrigerant, and gaseous to the steam supply line to the compressor. In addition, the ability to determine the ratio of thermal loads between air and liquid cooling condensers increases the cooling capacity of the installation both in winter and in summer.

SOURCES OF INFORMATION

1. Author's certificate No. 498454 (Russia) Refrigeration unit. M1Sh F2 5V1 / 00

2. Copyright certificate 1613820 (USSR) The method of operation of the refrigeration unit. Cl. P25B1 / 02 1990 Bull. Number 46

3.A.N. Kabakov, V.A. Maksimenko. Calculation and design of refrigeration units with air-cooled condensers. Uch. allowance: OMPI 1985 (p. 26)

Claims (1)

A refrigeration unit comprising a compressor and an air-cooled condenser, liquid-cooled condenser, throttle valves, an evaporator, a separation chamber, a liquid separator, irrigated nozzles and shut-off valves, characterized in that it further comprises a compressor and an evaporator, with t _o <t _o1 , where t _o is the boiling point of the refrigerant in the auxiliary evaporator, t _o1 is the boiling point of the refrigerant in the evaporator.