Transportable boiler plant with pulsating combustion boilers

Introduction

One of the strategic tasks of the next decades is the qualitative transformation in the energy complex of the national economy. Changes in energy belong to the most difficult in economic policy. The main goals of the energy strategy are the radical restructuring of the fuel and energy complex using the latest technologies, improving efficiency and ensuring the market conditions of its activities, as well as bringing to world-class requirements.

In the conditions of municipal reform and new economic relations, which require maximum reduction of the cost of generated and transported thermal energy, the development of fundamentally new energy-saving technological schemes, the use of materials and equipment, improving the quality of work during the reconstruction and new construction of heat supply sources require a new unconventional approach and new solutions.

Savings in fuel and energy resources - comparative in comparison with the basic, reference value of reducing the consumption of TER for the production of products, performance of works and provision of services of established quality without violating environmental and other restrictions in accordance with the requirements of society.

The main directions of energy efficiency improvement in the heat supply complex are:

- decommissioning of boiler houses that have lost their life;

- application of renewable sources of low-potential heat (heat pumps);

- modernization of existing boiler houses and construction of new ones using modern technologies and equipment with a efficiency of at least 92%;

- construction of new and replacement of existing heating networks with

the use of modern technologies;

- replacement of old heating boilers in residential and public buildings with individual heating systems with energy-efficient boilers with efficiency of at least 95%;

- Introduction and construction of decentralized heat supply sources.

Today, one of the most effective solutions for decentralizing heat supply is block-modular boiler plants with modern boilers.

"Block-module boiler plants" are designed for heating and hot water supply of industrial, administrative, cultural and domestic facilities: schools, hospitals, residential buildings, gyms, etc., and meet the requirements of existing norms and regulations.

Block-modular boiler plants "on pulsating combustion boilers are reactive (due to pulsating combustion) weapons of municipal reform due to their small size and low cost due to the street placement of boilers.

Characteristic features of the "Block-module boiler houses" are:

The maximum approximation to the heat supply object, which sharply reduces the cost of heat supply due to a decrease in heat losses and the cost of transporting thermal energy and operating engineering networks.

No significant capital expenditure and time to build a boiler room building.

Simple and convenient solution of the issue when decentralizing heat supply.

Minimum commissioning time from commencement of construction and installation works.

Minimum installation and start-up costs.

Easily relocated by rail, water, road or air.

The boiler room equipment used has an efficiency of at least 92%.

The boilers used have a low emission rate of harmful substances into the atmosphere.

Application of modern control protection systems.

General part

1.1 Boiler house characteristics

The transportable boiler plant is a complex of full factory readiness, including the main and auxiliary equipment located in a modular building with lightweight heat-insulating enclosing structures from three-layer sandwich panels, a gas control plant and boiler units in the amount of 4 pcs KVaP120Gn are located on an open area outside the building.

Boiler house building is made according to frame scheme. Frame elements - from steel unprotected structures. The walls are made of sandwichpanels thick. They use mineral wool insulation from basalt fiber, which refers to non-combustible materials. Sandwich panels correspond to the second degree of fire resistance. Roof coating - galvanized prof. flooring (non-combustible material, fire resistance degree - I). Insulation - minerolvate slabs P75 GOST 957396 (non-combustible material, degree of fire resistance - I) Internal finishing - steel profiled sheet (non-combustible material, degree of fire resistance - I).

Door - insulated metal (non-combustible material, fire resistance degree - I).

 Windows - PVC blind with one glazing row, with glass thickness (hard-burning material, fire resistance degree - III).

The transportable boiler plant is located in the city of Lozovaya, Kharkov region. The boiler house operates on gaseous fuel and is designed to heat the network water used in the heating and hot water supply system of the buildings of the Lozovaya railway station.

The boiler room is automated and designed for operation without permanent manpower. Control of coolant temperature at boiler room outlet is provided depending on ambient air temperature.

Climatic data of the city where the boiler house is located:

- design ambient temperature for heating design - to = 22 0C;

- average temperature of external air for the heating period - tcp. about = 0.80C;

- outside air temperature of the coldest month - tx.m = 5.60C;

- heating period duration - no = 194 0C.

Heat supply system - closed.

The water temperature in the supply pipeline of the heat network is 95 0C.

The water temperature in the return pipeline of the heat network is 700C.

Type of installed boilers KVaP120Gn - 4 pcs.

Fuel used in the boiler house - natural gas from the Shchebelin-Kharkov gas pipeline, of the following composition:

CH4 = 92.8%; C2H6 = 3.9%; C3H8 = 1.0%; C4H10 = 0.4%; C5H12 = 0.3%

N2 = 1,5%; CO2 = 0.1%; H2 = 0%.

Lower fuel combustion heat Qcn = 37310 kJ/m3.

Boiler house water supply source - city water supply

Raw water quality indicators:

- total stiffness - 3.0 MHeq/l;

- calcium stiffness - 0 geq/l;

- alkalinity total - 2.5 mg/l;

- salt content - 270 mg/l;

- content of sodium cations in water - 0 mg/l.

1.2 Technical description and characteristics of KVaP120Gn.

Boiler unit is designed for heat supply of buildings and structures equipped with water heating systems with forced heating

circulation. In terms of efficiency, safety and fundamentally new heat generation technology, boilers have no analogues in Russia and the CIS, are one of the most technological examples of modern thermal power engineering. The boiler design is a full-assembly monoblock, supplied by the manufacturer to the installation sites in prefabricated form, including automation diagrams and connecting gas ducts .

The novelty of boilers lies in the principle of their operation, based on periodic volumetric (faceless) combustion of fuel, as well as in design features, the main of which are the absence of a burner as a separate product, an smoke pump, mechanically moving parts, i.e. the boiler is a boiler unit of full factory readiness.

Operation

3.1 Operation of plate heat exchangers

Basic Operating Requirements

During operation of plate heat exchangers it is necessary to observe the operating parameters of the apparatus specified in the specification (certificate). The main operating parameters of the heat exchanger are: temperature, pressure, flow rate and working medium.

Before putting the device into operation, it is necessary to check the compliance of the size of the plate pack tightening with the specified on the nameplate and make sure that all protective casings are installed.

The system in which the heat exchanger is installed shall be operated to avoid unexpected pressure and temperature surges.

In order to maximize the life of heat exchanger plate seals, the pressure and temperature in the heat exchanger should increase slowly.

To avoid a surge in start-up pressure, the valves behind the heat exchanger and the air valves must first be opened, if any. Valves in front of the heat exchanger shall be closed. After starting the pump, slowly open the shut-off devices in front of the device, observing the standards specified in the certificate of the device. Close the air valves after air outlet.

Close the valves in front of the heat exchanger slowly before turning off the pump. Rapid disconnection can cause pressure spikes, resulting in damage to the gaskets and leaks.

After the temperature and pressure reach the ambient parameters, lower the liquid from both sides of the heat exchanger and, if necessary, clean it.

Before putting the heat exchanger into operation after a long stop, it is necessary to visually check the condition of the plate stack. Seals shall be seated tightly in the locking grooves of plates or modules. There shall be no contamination on the surface of the plates and seals.

Tighten the studs to such an extent that the distance between the front and rear plates of the frame is not greater than that specified in the heat exchanger certificate. If the heat exchanger is leaking, tighten the plate stack by another 3% of this distance, but not more than until the minimum distance between the front and rear frame plates is reached (indicated on the nameplate).

Current Service

Plate heat exchangers, due to their design (high turbulence of flows in the channels between the plates), are less susceptible to contamination than other types of devices. Nevertheless, in the case of using contaminated media in the apparatus, it is impossible to avoid completely deposits.

An increase in the pressure drop on the apparatus (> 20%) or a decrease in the transmitted power (> 10%) compared to those given in the specification of the apparatus indicates contamination of the plates. In such a situation, cleaning of the heat exchanger is necessary.

In addition to regular cleaning of the surface of heat exchange plates, it is recommended to use measures to protect threaded connections from corrosion and damage (lubrication, the use of protective covers). In any case, ensure that the thread of the screw ties is not mechanically damaged or covered with a layer of foreign substances (e.g. paint, dirt, etc.). The corroded screw braces must be replaced because they are load-prone parts of the apparatus.

In the presence of thermal insulation, a method of fixing it should be provided that allows partial dismantling for regular external inspection of the apparatus.

With skilled operation, the maintenance of the device is reduced to replacing the seals that have expired, since the latter are prone to aging and have a limited service life.

When a leak occurs in the apparatus, the latter can be eliminated by dosing the package of plates on the apparatus unloaded from pressure to the size given on the nameplate. In this case, it is necessary to observe the tightening sequence in accordance with the technical documentation for the device.

Manual cleaning

Due to the flexibility of the plate heat exchanger design, it is possible to manually clean it with minimal labor costs.

To do this, disassemble the device in the following sequence:

- after the media is lowered from the heat exchanger and the protective casing is removed, remove the connections on the movable plate (if any) so that there is enough space for its displacement until the support itself;

-to avoid distortion of plates when opening, clean upper and lower guides and threads of screw ties;

- before opening the heat exchanger, it is necessary to mark the distance between the front and rear plates in order to perform the necessary tightening of the device during assembly;

- nuts of screw ties are released in the sequence specified in Fig. 3.1.1. To comply with the parallel release of the plates, each nut can be released at a time for no more than 2 turns. Repeat the nut release operation in this sequence until it is possible to remove the tie pins from the slots in the plates.

Literature

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