Exchange Rate Design - Boiler Unit Calculation

Contents

ANNONATION

INTRODUCTION

1 CALCULATION OF THERMAL CIRCUIT

1.1 Description of thermal circuit

1.2. Initial data for thermal circuit calculation

1.3 Calculation of thermal circuit

1.4 Schedule of central quality control of heat release for the heating and ventilation system

1.5 Annual Heat Flow Chart

1.6 Calculation of fuel consumption

2 BOILER ROOM EQUIPMENT SELECTION

2.1 Boilers

2.2 Pumps

2.3 Water heaters

2.4 Water treatment

2.5 Traction machines

2.6 Fuel supply

3 AUTOMATION

4 OPERATION OF MAIN AND AUXILIARY EQUIPMENT

4.1 Basic information on the organization of operating services of boiler houses

4.2 Rights and obligations of boiler house operator

4.3 Reception and delivery of shift. Boiler mode map

4.4 Preparation of boiler for ignition

4.5 Combustion of boilers during combustion of gaseous and liquid fuel

4.6 Actuation of the boiler

4.7 Boiler maintenance during operation

4.8 Periodic boiler blowdown

4.9 Boiler emergency shutdown

CONCLUSION

LIST OF LITERATURE

Thermal Diagram Description

Saturated steam from boilers with operating pressure P = 0.8 MPa is supplied to the common steam line of the boiler house, from which part of the steam is taken to the equipment installed in the boiler house, namely to: network water heater; hot water heater; deaerator. The other part of the steam is directed to the production needs of the enterprise.

Condensate from the production consumer spontaneously is returned, of 30% at a temperature of 80 wasps, in a kondensatosbornik and further the condensate pump goes to a tank of hot water.

Heating of the network water, as well as heating of hot water, is carried out by steam in two heaters connected in series, while the heaters operate without condensate drains, the spent condensate is sent to the deaerator.

The deaerator also receives chemically purified water from the CWC, making up for condensate losses.

The raw water pump sends water from the city water supply line to the CWC and to the hot water tank.

Periodic blowdown from boilers in the amount of 2% is sent to the bubbler.

Deaerated water with a temperature about 104 wasps the nutritious pump is forced in economizers and further comes to coppers.

Make-up water for heat supply system is taken by make-up pump from hot water tank.

The main purpose of calculating the thermal scheme is:

determination of total heat loads consisting of external loads and steam consumption for own needs;

determination of all heat and mass flows required for equipment selection;

determination of initial data for further technical and economic calculations (annual heat, fuel production, etc.).

Calculation of the thermal circuit allows to determine the total steam efficiency of the boiler plant at several modes of its operation.

Calculation is performed for 3 characteristic modes:

maximum winter;

coldest month;

summer.

Take and take the shift. Boiler mode map

Operators are on duty in boiler rooms according to the schedule. When taking a shift, the operator is obliged to come to work ahead of time (10 sound15 minutes), check the entries in the shift log for the previous three shifts, familiarize himself with changes in the operation of the main and auxiliary equipment, malfunctions and malfunctions.

The shift operator must familiarize the shift operator with the state and mode of operation of the equipment, the load of boilers, the equipment that is in reserve and repair, inform about what work has been carried out and what else needs to be done.

The operator who takes the shift must check:

- serviceability of lighting (emergency and explosion-proof design);

- water treatment operation and water level in the deaerator;

- condition and position of disconnecting devices, both on operating boilers and in reserve and repair;

- absence of gas leakage in gas pipelines upstream of boilers and distribution gas pipeline;

- water level in steam boilers by water indication instruments and correctness of their operation (by blowdown method);

- pressure of steam in the boiler by pressure gauge, its serviceability and presence of seals;

- reliability of safety valves operation by blasting method, presence of seal or lock on control valve;

- condition of heating surfaces, which is visible through the inspection window of the boiler furnace: whether there are bulges, leaks, soaring, etc.;

- serviceability of standby feed and circulation pumps (by short-term actuation method);

- operation of gas burners (if necessary, adjust combustion);

- presence of thrust in boiler furnace;

- condition and operation of traction devices, pay attention to oil level and temperature in oil baths, bearing heating and presence of knock and noise in operating smoke pumps and blast fans.

The reception and delivery of the shift is executed by an entry in the shift log indicating the results of the inspection, and is sealed by the signatures of the receiving and delivery and delivery shift. The first signs the receiving and then the passing shift.

It is forbidden to accept and hand over a shift during the liquidation of an accident in the boiler room.

Mode cards.

The operating mode maps of the boilers are compiled by the commissioning organization based on the results of heat engineering tests.

They accommodate parameter values that ensure safe and cost-effective operation in the desired range of performance. Tests shall be carried out at least once every three years.

The mode map is 30%, 50%, 75% and 100% of the capacity of the boiler and is the main operational document according to which the operating personnel regulates the operation of the boiler when its capacity changes. In the boiler room on each boiler there should be a duplicate of the control card indicating the date of its compilation, signed by the representative of the commissioning organization and approved by the chief engineer of the enterprise.

Preparation of boiler for ignition

Before igniting the boiler, the operator shall carefully check:

a) the availability of the order of the head of the boiler room on the ignition of the boiler, where the ignition time should be indicated, the temperature of the water to which the boiler should be filled, as well as the duration of ignition;

b) serviceability of furnace and gas ducts, shut-off and control devices;

c) serviceability of instrumentation, valves, headset, feeders, smoke pump and fan;

d) serviceability of equipment for combustion of gaseous (liquid) fuel;

e) filling the boiler with water to the lower working level elevation. Fill by air release;

f) maintaining the water level in the boiler, the presence of its passes through the flanges and valves;

and) there are no plugs before and after the safety valves on steam, oil and gas pipelines, on feed, drain and purge lines;

g) absence of people or foreign bodies in the furnace and gas ducts;

h) presence of the required fuel pressure for operation of gas burners or fuel oil nozzles.

Immediately before igniting the boiler, it is necessary to carefully ventilate the furnace and gas ducts for 10-15 minutes.

Before switching on the smoke pump for ventilation of the furnace and the gas ducts of the boiler, which operates on gaseous fuel, it is necessary to make sure that the rotor does not touch the body of the smoke pump, for which the rotor is scrolled manually.

Before igniting the boiler, when operating on gas, it is necessary to:

- check serviceability of gas pipeline and valves installed on it (all shut-off valves on gas pipelines must be closed, and blowdown "plugs" - open);

- blow the gas pipeline through the blowdown "candle," gradually opening the gate valve on the branch of the gas pipeline to the boiler, after blowing the "candle" close;

- make sure that there is no gas leakage from gas pipelines, gas equipment and valves;

- check absence of gas and air pressure upstream the burner by pressure gauge;

- adjust the thrust of the ignited boiler by setting the minimum discharge at the top of the furnace at the level of 1-1.5 mm. waters. St.

Before igniting the liquid fuel boiler, the fuel temperature must be adjusted to the value specified in the instruction.

The steam line to the nozzles must be warmed up.

Ignition of boilers during combustion of gaseous and liquid fuel

Boilers are ignited for a period of time set by the administration, with low fire, reduced thrust, closed steam valve and open safety valve or air outlet valve. During ignition of the boiler, it is necessary to ensure uniform heating of its elements, and if the boilers have a device in the lower drum for heating water, then it is necessary to turn it on.

Ignition of gas burners.

The gas burners shall be fired in the following order:

- add a lit igniter to the furnace (through the panel) to the gas outlet holes of the burner;

- supply gas, slowly opening the operating valve (gate valve) in front of the burner and ensuring that the gas lights up;

- set the gas pressure on the burner (30% according to the mode map),

- adjust combustion (by air supply and regulating rarefaction) by the color and nature of the flame,

- after obtaining a stable flare, extinguish the igniter and remove it from the furnace.

If the flame of the igniter or burner goes off during ignition, it is necessary to immediately stop the gas supply to the burner, extinguish the igniter and remove it from the furnace, ventilate it and the gas ducts for 1015 minutes. Only then you can start igniting the burner again.

If there are several burners in the boiler, their ignition is performed

sequentially in such an order as not to make temperature distortions in the furnace.

If all or part of the ignited burners go off during ignition, immediately stop the gas supply to them, extinguish by

finger and take it out of the furnace, ventilate the furnace and gas ducts

for 1015 minutes. Only then can the burners be re-ignited.

Actuation of the boiler

Before starting the boiler, perform the following:

a) serviceability check of warning valves, water indication devices, pressure gauge and feeders;

b) check and actuation of safety automation, regulation and signalling;

c) boiler blowdown.

Do not turn on boilers with faulty valves, feeders, safety automation and emergency protection and alarm devices.

The boiler shall be incorporated into the common boiler steam header slowly, after careful heating and blowing of the header. During heating it is necessary to open the valve on the drain line for condensate discharge. Open the main steam shut-off valve smoothly, but not more than 50%. When the steam line warms up, open the main steam shutoff valve completely.

During heating monitor serviceability of the manifold, its supports, as well as uniform expansion. In case of vibration or sharp shocks, it is necessary to stop heating until the detected defects are eliminated.

When the boiler is switched on to the active steam header, the pressure in the boiler must be equal to the pressure in the active steam line or 0.5 kgf/cm2 less than the pressure in the steam line (header), at that combustion in the furnace should be reduced. If in this case shocks or hydraulic shocks occur in the steam header, it is necessary to immediately stop switching on the boiler and increase the blowdown of the common boiler steam header.

Ignition start time and boiler activation is recorded in the replaceable log.

Boiler maintenance during operation

During the duty, the boiler room personnel must constantly monitor the serviceability of both the main and auxiliary equipment and strictly adhere to the established boiler operating modes

Faults detected during equipment operation shall be recorded in the replaceable log. Personnel shall immediately take measures to correct faults that threaten the safe and trouble-free operation of the equipment. If it is not possible to eliminate the malfunctions on your own, it is necessary to notify the person responsible for the safe operation of the boiler room.

Special attention should be paid to:

a) maintenance of normal water level in the boiler and its uniform supply with water. At the same time, the level should not be allowed to decrease below the lower level or rise above the highest permissible levels of water in the boiler;

and b) maintaining the normal operating pressure and temperature of steam generated by the steam boiler. Increase in pressure or temperature above

permitted levels are strictly prohibited.

c) maintaining the required temperature of the feedwater after the water economizer;

d) normal operation of burners.

Special attention should be paid to the serviceability of the boiler room equipment, instrumentation and automation system.

The serviceability check of the pressure gauge by means of a three-way valve or shutoff valve, which replaces it, must be carried out at least once per shift.

Blasting safety valves shall be checked for working pressure boilers:

- up to 24 kgf/cm2 - each valve is not less, just per shift,

Inspection of water-indicating devices shall be performed by blowing for boilers with working pressure;

- up to 24 kgf/cm2 - at least once per shift;

Serviceability check of feed pumps shall be performed by short-term start-up of each of them for boilers with operating pressure:

- up to 24 kgf/cm2 - within the terms specified by the production instruction. All specified checks are recorded in the shift log with indication of time

With an increase in the load of the boiler, which operates on natural gas, it is necessary to gradually increase the gas supply first, then air and adjust the vacuum, and to reduce it, first reduce the air supply, then gas; then adjust the vacuum

If the boiler runs on liquid fuel, then to increase the load, first increase the vacuum, then air, and then fuel oil supply (steam nozzles increase the steam supply before increasing the fuel oil supply); to reduce - first, the supply of fuel oil, (steam for spraying), air, and then vacuum is reduced.

Periodic boiler blowdown

Periodic purging of the boiler is carried out after a certain period of time and serves to remove sludge and dirt from the lower points: drum, collectors.

It is carried out for a short time, but with a large release of boiler water, capturing during its movement the sludge located in the drum or headers, and carries it to the so-called expander (bubbler), designed to cool the boiler water. Cooling is carried out by mixing it with cold tap water to a temperature of 6070 ° C, at which it can be discharged to the sewer.

Periodic blowing is carried out at least once a shift. In case of poor quality of feedwater, on the recommendation of the laboratory assistant, water treatment is repeated. The duration and order of this operation are specified in the production instruction for each boiler. The boiler house personnel, as well as everyone involved in the repair of neighboring boilers, warn about the blowdown. When the purge valves are placed near the front of the boiler, one operator can purge, and if it is located on the sides and rear of the boiler, it is performed by two operators. Periodic purging is performed in the following sequence:

Check serviceability of blowdown lines to touch. The pipe must be hot before the first valve and cold after the second valve. Reinforcement is checked for ease of rotation of valve flywheels.

Serviceability of feed pumps and availability of sufficient supply water are checked.

Water-indicating devices are blown.

Boiler is fed up to upper working level or by 3/4 via water-indicating device.

Combustion in the furnace is reduced.

In the line to be blown first, the second blowdown valve is first carefully opened downstream of the boiler, and then the near-boiler blowdown valve is slightly weakened to warm up the blowdown line. After heating, it is carefully opened. At this time, the second operator must monitor the water level in the boiler and the steam pressure in the drum. In case of hydraulic shocks, pipeline vibration or other malfunctions in the purge lines, the purge shall be stopped.

When the water level decreases to the lower operating level (according to the signal of the second operator), the blowdown valve (the first) closest to the boiler is gradually closed, and then the second one.

In the same way, the remaining lines are blown, observing the water level.

After completion of the boiler blowdown, make sure that the blowdown valves are safely closed and put the boiler into normal operation.

Make a record in the replaceable log showing the purge start and end time.

In 30 minutes it is necessary to check how tightly the purge valves are closed. If the valves pass water, then you should inform the head of the boiler house and continue to monitor the water level in the boiler.

Normal boiler shutdown.

The stopping of boilers is normal - by written order of the person responsible for the boiler room, and emergency, which is carried out without an order with subsequent notification to the administration.

Normal stop sequence:

- reduce the boiler load if possible in several stages (100%, 75%, 50%, 30%), achieving gradual cooling of the boiler and furnace;

- switch off the gas burners - close the "working" valve (gate valve) and the "control" valve (gate valve), open the blowdown "plug" between them;

- close the gate valve on the gas pipeline in front of the boiler and open the purge plug of the gas header of the boiler;

- disconnect the boiler from the common boiler steam header;

if the pressure in the boiler rises above the permissible one, release it through the safety valve to the atmosphere;

- maintain the boiler water level between higher and lower as necessary;

- after 1015 min turn off the fan and smoke pump, further cooling of the furnace is carried out naturally. Repeated artificial ventilation of the furnace is allowed only after 6-8 hours;

- make a record in the replacement log about boiler shutdown with indication of time.

Cooling of the boiler should be carried out slowly due to natural cooling: doors, hatches and eyes should be kept closed.

Rapid cooling can result in impaired boiler tightness. The water must be lowered from the boiler only after the pressure drops to zero, the temperature drops to 7080 ° C and the masonry cools down. The descent should be done slowly and with the safety valve raised.

After water is lowered, plugs are installed on steam, feed, purge and discharge lines of the boiler unit, which is switched off, in order to separate it from other operating boilers. Only then can any repair work be carried out on it.

It is strictly forbidden to leave a non-operating boiler unit connected to a common boiler steam header, since in this case steam can enter its drums. At the same time, water flow in the seams and roller joints may appear, which may cause the drum walls to warp.