Course project on the topic "Calculation and selection of a refrigerator for a poultry farm"

Contents

Introduction

1 Objectives and objectives of the course project

2 Thermal calculation of refrigeration machine

2.1 Design temperature mode of refrigerating machine

2.2 Thermal calculation of two-stage refrigerating machine. Calculation and selection of compressors

2.2.1 Calculation and selection of compressors

3 Calculation and selection of heat exchange equipment

3.1 Calculation and selection of capacitor

3.2 Calculation and selection of chamber cooling devices

4 Calculation and selection of auxiliary equipment

4.1 Calculation and selection of receivers

4.2 Calculation and selection of oil separator

4.3 Calculation and selection of centrifugal pumps

4.4 Cooling tower calculation and selection

4.5 Piping Calculation

5 Description of refrigeration unit diagram

Conclusion

List of sources used

Appendix A

Appendix B

Introduction

Refrigerators are a device for cooling, freezing and storing perishable products.

A prerequisite for maintaining food of high quality is the creation of a continuous refrigeration chain, which ensures that food products are exposed to low temperatures throughout the time from the moment of production or preparation of the product to the moment of consumption.

Refrigeration equipment is a type of device that creates and uses cold to preserve the quality of meat, fish, oil, milk, vegetables, fruits and other perishable products. In recent years, the latest developments of foreign firms have become available to the Russian consumer of refrigeration equipment. The result of this was the saturation of the Russian market with trading refrigeration equipment, updating the assortment and improving the quality of domestic refrigeration equipment.

Refrigeration equipment is widely used in the food industry, agriculture, trade, transport and other industries. Food traders have to store substantial stocks of goods, many of which are perishable. The best way to store them is to use Cold.

Production refrigerators are built at poultry farms, meat processing plants, fish processing plants, dairy plants, oil and food plants, vegetable storage facilities.

Chita is the center of the Trans-Baikal Territory and the Chita District. It forms the municipality of the urban district of the city of Chita as the only settlement in its composition.

Poultry farm - an enterprise for the production of poultry products on an industrial basis. Mainly located near large cities and industrial centers to provide the population with dietary eggs and steamed bird meat.

Cooling poultry carcasses after potting is an important part of the technological process, necessary to increase the shelf life of cooled semi-finished products.

To store chilled products, medium-temperature chambers will be required, but another production stage will be added for frozen products: in order for poultry meat not to lose its properties, it is necessary to use shock freezing technology. Shock freezing allows you to preserve the structure of meat and is carried out using tile or tunnel frost devices.

Objectives and objectives of the course project

Purpose of the course project:

Application of the acquired knowledge on calculation and selection of the main and auxiliary refrigeration equipment, design of the refrigeration unit diagram.

Course Project Tasks:

- Development of self-employment skills;

- application of legislative, regulatory and design documentation to solve technical issues;

- manifestation of the skills of systematization and analysis of data obtained from educational and periodical literature.

The task for the course project includes:

refrigerant boiling point - t01 = - 10 ° С; t02 = - 30 wasps

and their respective thermal loads on compressor equipment (cooling capacity) - Q01 = 120 kW; Q02 = 110 kW

condenser type - air;

the city is Chita.

Thermal calculation of refrigerating machine

The tasks of the thermal calculation of the refrigerating machine are:

- determination of required volume capacity of the compressor;

- compressor selection;

- determination of power consumption;

- determination of heat load on the condenser.

Initial data for thermal calculation:

- the required cooling capacity of the machine, taken equal to the thermal load on the compressor;

- design diagram of the refrigerating machine;

- design temperature mode of the refrigerating machine.

Description of refrigeration unit diagram

The designed plant uses a two-stage compound scheme for two boiling points with parallel throttling and compression of coolant.

The scheme is designed for two boiling points: t01 = 10oC, t02 = 30oC according to the task for the course project .

Coolant in liquid state is supplied to receiver through solenoid valve CB, which opens by command of level relay. Liquid coolant is throttled in the manual control valve RV installed after the solenoid valve.

In the above diagram of a two-stage cooling unit with two boiling points, two single-stage screw compressor units are used:

- boiling point t01 = 10oC - CTXR 1 E;

- for boiling point t02 = 30oC - CTX204 A.

The CTXR 1 E screw single stage compressor unit installed at the high pressure stage (HPA) can suck coolant vapors as from the circulation receiver at boiling point t01 = 10oC.

The compressor shop also has: horizontal circulation receiver of size BCLRH160.0 3SG,: linear receiver IGBH - 3, vertical oil separator of the cyclone type BCOSH579.

The compressor unit CTX204 A, which maintains the temperature t02 accordingly, sucks steam from the circulation receiver 5 and pumps it to the compound receiver 6 for cooling. The compressor unit 2 of the high pressure stage sucks steam from the compound receiver 6, maintaining the temperature t01, and pumps it to the condenser 1, in which the steam condenses. The resulting condensate flows into the linear receiver 7. Liquid coolant is supplied from linear receiver by throttling in control valve to pressure p01 to compound receiver 6. Then, throttling the second time in the control valves, it enters the circulation receiver 5 with pressure p02.

Liquid coolant from compound 6 and circulation 5 receivers is supplied to cooled objects with temperatures t PM1, t PM2 by pumps, and steam formed in cooling devices and unspoiled liquid are returned to the receiver and separated.

The advantages of this compound refrigeration plant are a reduction in the number of devices (industrial vessels), a reduction in the length of pipelines, the number of valves, automation devices.

The composition of the compound refrigeration unit may not include linear and drainage receivers, and compression and throttling processes may be carried out with less thermodynamic losses.

Conclusion

After studying and analyzing theoretical and practical aspects, a calculation of refrigeration equipment for a poultry farm was made.

During the work, two single-stage screw compressor units of the STX brand were selected.

The helical single-stage compressor unit of CTXR 1 E grade was selected for boiling temperature t0 = 30 0C. The helical single-stage compressor unit of CTX204 A grade was selected for boiling temperature t0 = 10 0C .

After that, 2 air condensers of the ACS902A grade were selected. A capacitor of this type was chosen for a number of advantages over others: 1. Much less occupied area; 2. Significantly lower consumption of expensive seamless pipes; 3. The possibility of changing the area of the heat transfer surface when changing the thermal load ;

4 air coolers of type CCEH504.2C 70 were selected (with two fans with a diameter of 500 mm, rib pitch of 7 mm, heat exchange surface area of ​ ​ F = 248.0 m2) for better heat transfer capacity.

The compressor shop also has: linear receiver of IGBH grade - 3 with a capacity of Vl. R = 3.1 m3, horizontal circulation receiver BCLRH160.0 3SG, vertical circulation receiver BCLR160.0 3SG, vertical oil separator of cyclone type BCOSH579, oil separator 10SG