Ammonia piston compressor - drawings

Contents

Source data4 pts

Enter 5 st

Description of compressor operation and design .6 ft

Thermal calculation of compressor in operating mode.. 7 st

Schematic diagram, cycle 7 pts

Thermal calculation...... 7 st

Design selection and optimization of main compressor parameters9

Calculation of compressor gas path.. 11 st

Determination of diameters of suction and delivery branch pipes... 11 ft

Calculation of main parameters of the suction valve... 11 st

Calculation of main parameters of the pressure valve.... 12 ft

Dynamic calculation... 14 st

Determination of mass of unbalanced moving parts........... 14 ft

Construction of the calculated indicator diagram.

First and second order inertia forces............. 17 st

Plotting Free Amplies18 pts

Plotting tangential silences.19 st

Definition of fly masses and flywheel design... 20 st

Building a Radial Sil21 Diagram

Balancing the forces of inertia... 22 st

Counterweight construction.23 str

Strength calculation of compressor parts 24 pts

Determination of compressor motor power... 25st

Determination of the cooling capacity of the designed compressor at the standard operating mode 26 pts

Attachments .27 st

List of used literature.. 30 st

Project Description

The course work contains 4 sheets of drawings, an explanatory note of 30 Art., 6 tables, 4 drawings, bibliographies of 5 sources, 3 annexes.

AMMONIA COMPRESSOR, THERMAL CALCULATION, DESIGN SELECTION AND OPTIMIZATION OF PARAMETERS, GAS PATH CALCULATION, DYNAMIC CALCULATION, STRENGTH CALCULATION.

The object of development is a refrigerated four-cylinder compressor for working on ammonia.

The purpose of the course design is to design the compressor based on the data obtained during the calculation. The calculation is based on the specified source data.

Thermal calculation was carried out to determine the main performance characteristics: volumetric productivity, compressor power consumption, as well as an effective cooling factor.

At the input of the gas path calculation, the area and main dimensions of the flow sections of the valves were determined, determined based on the condition of limiting losses to overcome the gas dynamic resistance in them based on permissible flow rates of refrigerant steam.

During dynamic calculation forces and moments acting in compressor are determined, counterweight and flywheel are calculated.

Strength calculation was carried out in order to evaluate the strength of compressor parts at stresses arising in the sections under consideration.

The designed design of the compressor is recommended for implementation on ships of the transport and fishing fleet.

Task

Source Data:

Working substance

R717

Cooling capacity Q0

50 kW

Boiling point t0

- 100C

Condensation temperature tc

200C

Compressor type: Gland.

Introduction

The compressor is the main and most complex unit of the steam refrigerator. It is designed for constant suction of steam formed in the evaporator during boiling of refrigerant, compression and its delivery to the condenser.

Refrigeration compressors designed to operate in a wide range of suction and discharge pressures are considered universal. These are compressors of single-stage refrigerators.

Ship refrigeration units are usually provided with medium and large gland compressors. Modern compressors are made multi-cylinder (from 2-4 to 16 cylinders), medium and high-speed: relatively short-speed with an S/D ratio of the piston stroke to the cylinder diameter of 0.6-0.8 and a rotation speed of 800-1750 rpm.

The increase in the number of cylinders and the creation of spatial schemes of their location made it possible to solve the problem of complete balancing of inertia forces and apply multi-rotation - the main means of reducing mass per unit of productivity.

The compressors of ship refrigeration plants, in addition, are subject to the requirements of high reliability of operation with a large motor resource. One of the important conditions for ensuring this is the high quality of the material and the manufacture of compressor parts, their uninterrupted lubrication at roll, trim and under rolling conditions.

The general trend in modern refrigeration compressor construction, characteristic of domestic plants and advanced foreign companies - the transition to single, extremely unified compressors operating on freons 12, -22, 502, ammonia; application of non-winding structures with peripheral arrangement of suction valves and regulation of cooling capacity; expanding the range of performance by increasing the number of cylinders and changing their diameters; high quality of manufacture, as well as the use of high-quality materials; reduction of weight and overall dimensions of compressors due to forcing of loads and application of light alloys; reducing noise and vibration, for which dynamically balanced shafts operating in sliding bearings are used; careful development of lubrication and filtration system, application of viscous oils with various additives.

Description of operation and design of piston compressor

The compressor is ammonia gland-free, blockcarter, single-stage, four-cylinder, V- shaped, medium-cooling capacity, non-flushing, casings, with an angle between the axes of the cylinders 900.

Pump lubrication system. For lubricant HF22 oil is used. Submerged pump type. A slotted filter is built into the injection oil line, which provides filtration and removal of particles larger than 90 mcm.

Gas filter and suction valve are built in split between cylinders.

Suction valves - annular plate, spring, located peripherally around the cylinder; delivery - annular plate.

Cylinder block with suction and delivery cavities are combined in cast-iron block case. Crankcase has two supports for crankshaft rolling bearings. Liners are pressed into cylinder block. Cover is attached to crankcase on its end side. Crankshaft - steel, two-support, with counterweights, two-collar with a break angle between the connecting rods 180 °. The main bearings are roller, two-row, self-aligning.

The drive end of the shaft is sealed with an end, two-sided, spring, self-aligning gland with a pair of friction: metal-impregnated graphite - walled steel.

Connecting rod - steel, stamped. The lower head of the connecting rod is detachable. The bottom head has a babbit fill.

Piston - aluminum of the throne type, impassable, with two sealing and one oil-collecting rings. Piston pin - hollow, steel, floating.

Principle of operation: refrigerant vapors are supplied through suction branch pipe to suction chamber of CM; Then, vapors through special holes and suction valves are sucked into cylinders, where refrigerant vapors are compressed and sent to delivery branch pipe through delivery valves.