Monthly Archives: May 2016

Boilers: Various Types and Classification

In today’s energy work a variety of types of boilers. They can be classified by type of fuel, coolant type, accommodation type, level of mechanization. The specific type of boiler is selected depending on the goals and objectives, operating conditions and customer requirements.

Fuel type

Gas: The advantage of this kind of boiler is that the gas – one of the most economical and environmentally friendly fuels. Gas boiler does not require complicated and cumbersome equipment fuel and slag removal, and can be fully automated.
Fuel oil: These boilers can run on waste oil, fuel oil, diesel oil. They quickly put into operation, do not require special permits, the connection negotiation, obtaining gas limits (as opposed to gas).
Solid: To the solid fuel concerns coal, peat, wood, pellets and briquettes from waste wood processing and agriculture. The advantage of this type of boiler is the availability and low price of fuel, but it requires the installation of fuel and ash handling systems.

Coolant type

Steam: In such a boiler heat carrier is steam, which is used mainly for manufacturing processes in industrial plants.
Water: This type of boiler is designed for heating and hot water supply of residential buildings, industrial and public facilities. The coolant is water, heated to +95 +115 ° C.
Combined: In these boilers are placed as steam and hot water boilers. Hot water is used to cover the load for hot water, heating and ventilation, and the steam is supplied to provide the technological needs of the enterprise.
Diathermic oil: In this boiler is used as a coolant in the high-temperature organic liquid, the temperature of which can reach +300 ° C.

Accommodation type

Modular: This type of boiler is becoming increasingly popular in Russia in recent years, thanks to many advantages in comparison with stationary boilers: fastest time of installation and commissioning, factory-assembled modules, the ability to increase capacity by adding units, battery life, high efficiency, mobility. Depending on the placement of block-modular boiler can be detached, and attached, integrated, roof, basement.
Stationary: Stationary boilers are usually built when the required power exceeds 30 MW, or the construction of a modular boiler for some reason impossible. Stationary boilers distinguished by major building and construction (foundations, walls and partitions, roof). Installation of equipment on site is performed.

The level of mechanization

Depending on the degree of mechanization / automation processes are the following types of boiler:

Hand: Small boilers can be equipped with boilers, in which the fuel supply is performed manually by operators. The fuel is supplied to the boiler room truck or in some cases from the outside through a loading hopper. The ash and slag from the ash hopper and are removed manually by the operator and exported outside the boiler room via trolley.
Mechanized: Modern boilers are equipped with solid mechanization, significantly facilitate the work boiler operator. Fuel supply by means of conveyors or skip hoists. Coal is pre-processed. The ash and slag may be removed by various methods – mechanical, hydraulic, pneumatic or a combination thereof.
Automated: This type of boiler assumes full automation and minimal presence of the human factor. Fully automated, as a rule, gas boiler.

Energy-saving technologies in Modern chillers

In the development of modern HVAC equipment of particular importance is given to the problem of energy conservation. The amount of energy consumed by the equipment during the annual life cycle is one of the main criteria for decision-making when considering proposals submitted to tender. To date, a significant potential for energy efficiency is the development and establishment of climatic equipment, able to cover as precisely as possible the load schedule in constantly changing conditions

At the same time, the daily schedule of excess heat is also uneven pronounced maximum. Traditionally, chillers with capacity of 20-80 kW installed two identical compressors and make the two independent refrigerant circuits. As a result, the machine can operate in two modes at 50% and 100% of its rated capacity. The new generation of chillers with cooling capacity from 20 to 80 kW allows you to perform three-stage capacity control. In this case, the total refrigerating capacity is distributed among the compressors in a ratio of 63% and 37%.

The new generation of chillers both compressors are connected in parallel and operate on a single refrigerant circuit, that is, have a common condenser and evaporator. This arrangement significantly increases the energy conversion efficiency (KPI) of the refrigerant circuit when operating at part load. For such chillers at 100% load and outdoor temperature of 25 ° C KPE = 4, and at the 37% CPE = 5. Given that 50% of the time the unit is working with a load of 37% of this gives a considerable energy saving.

Microprocessor controllers

Microprocessor controllers are set for the effective implementation of new solutions in the chillers, which allow:

control all the operating parameters of the equipment;
adjust the set point temperature of the water at the outlet of the unit in accordance with the parameters of the outside air, process or commands from a centralized control system (supervisor);
selects the optimal power control step;
In the case of real need to quickly and effectively perform a defrost cycle (for heat pump models).

As a result, an automatic compressor to minimize the short-inclusions, optimize working hours of compressors and the adjustment parameters of the water leaving the chillers in accordance with real needs. As on average, it takes place during the day only 22 incorporating compressor while the compressor includes conventional chiller 72 times.

Another important advantage which enables the use of new chillers, is that eliminates the need for installation of bulky storage tanks and built into the body of the unit circulation pump eliminates the need for an additional pump station.

Energy-efficient gas compressor

As you know, for the accurate performance load curve of the chiller is very important type of used compressors. Traditionally, large capacity chillers used piston or rotary screw compressors. The reciprocating compressor has many moving parts and, consequently, low efficiency due to large frictional losses. In the operation of reciprocating compressors there is a high level of noise and vibration, as well as there is a need for their regular maintenance. Screw compressors, in turn, have a complex structure, and as a result, very high cost. Production of screw compressors is low-profit.

Service of such compressors consuming and requires highly skilled personnel. In recent years, the market of new type of compressor SCROLL appeared that lack specific deficiencies reciprocating and screw compressors. Scroll-compressors have a high energy efficiency, low noise and vibration, and require no maintenance. This type of compressors is simple in construction, is very reliable and, at the same time is inexpensive. However, performance Scroll-compressors usually does not exceed 40 kW.

Selection of Industrial Refrigeration Equipment

Choosing industrial refrigeration equipment for enterprises, primarily necessary to define what tasks you are going to put in front of him and try to take into account all the factors that will continue to affect the performance of the system cooling. Such options may be few, but you need to choose the most optimal.

To correctly determine the choice of refrigeration equipment must always take into account the system parameters such as:

extreme heat
the amount of heat in a time interval,
Hydraulic resistance, as well as pre-agree on the heat dissipation and duplication systems.

As practice shows, in most cases, for a rational use of the equipment necessary to install more than one cooling system, and more. This is because the performance of the equipment at different times can be different: for example, a higher weekdays and weekends – lower. In such cases it is sufficient to install a small, which will increase the wear resistance of the cooling system and save on operating costs.

When choosing a pump to circulate the fluid, you will need to take into account the following factors: the diameter of the pipes, liquid lifting height and its distance from the energy source.

If the result of calculating the cost of refrigeration equipment coincides with the cost of downtime of the equipment, then we can consider the option of picking system spare equipment. In this case the two systems communicate with each other by the control unit, which in the case of an emergency or an unexpected stop of the main equipment will automatically turn spare.

Chiller Purchasing equipment with a powerful electric drive, you should consider that it has a limited number of starts per hour and running at the same time in the most unfavorable mode. Starting currents in this case is increased tenfold, and increases heat power cable is hundreds of times.

In contrast to the rated speed, increasing the current strength affects the torque, which increases at the start of dynamic impact on the shaft, bearings and couplings. Now, having seen the consequences of such a choice, you can imagine how many are able to serve in a similar refrigeration equipment operating conditions.

Absorption chiller – Advantages

Absorption chillers – a very promising field of refrigeration, is becoming more widely used because of the pronounced tendency to modern power management. The fact is that for absorption chillers main source of energy is not electricity, and waste heat that inevitably occurs in plants, factories and so on. N. And irrevocably thrown into the atmosphere, whether it is hot air, cooling air hot water, and others.

The main advantages of absorption chillers:

The ideal solution for creating tri-generation enterprise. Tri generation complex – a complex allows to date as much as possible to reduce the cost of electricity, hot water, heating and cooling for the enterprise through the use of its own cogeneration power plant in conjunction with an absorption chiller;
Long service life – within 20 years before the first major overhaul;
Low cost of produced cold, cold is produced almost free of charge
Reduced noise and vibration as a result of the lack of compressors with electric motors, as a consequence – quiet operation and high reliability;
The use of refrigeration / heating units with the flame of a gas generator of direct action eliminates the boilers to be used in conventional installations. This reduces the initial cost of the system and makes absorption chillers competitive compared to conventional systems, which utilize boilers and chillers;
Maximizing energy savings during periods of peak demand. In other words, do not consume electricity for the production of cold / heat absorption chillers do not overload the power supply enterprise, even in times of peak demand;
There is the possibility of combining in the district steam systems with efficient refrigeration unit of double effect;
It is possible to load balancing in conditions of maximum efficiency in the cooling mode. The device handles the critical load in the cooling mode, with minimal power consumption through the use of refrigerants with a flaming gas generator direct effect or generator with steam heating;
It allows the use of emergency generators at the power, as energy consumption in absorption chillers is minimal when compared with electric refrigeration units;
Security for the ozone layer does not contain refrigerants that deplete the ozone. Cooling is carried out without the use of refrigerants containing chlorine;
Minimizes the overall impact on the environment as the consumption of electricity is reduced and the gas causing the greenhouse effect and global warming as a consequence.