Condensate pumping stations
Steam condensate as an economically important resource
In the working circuits of various steam power machines and heat exchangers operating with sharp (overheated) or saturated steam, its partial condensation is inevitable, with the formation of the so-called. condensate (in the form of liquid water), which has an elevated temperature (sometimes up to 300 degrees C), and pressure. In the working circuit of the steam consumer, water condensate is definitely an undesirable element that causes erosion, water hammer, and must be removed from it into the waste (outlet or drainage) system. This problem is solved mainly with the help of special pipeline fittings - steam traps.
But simply discharging condensate into the drainage system is economically insufficient. Thus, condensate discharged from the steam consumer circuit is still an important resource with significant technical and economic value and must be used and stored in the circuit.
Condensate from steam power machines and industrial heat exchangers has a high residual temperature. A significant part of the heat energy spent on heating it can be utilized and used for technological (for example, return water make-up, saturated secondary boiling steam), household or domestic purposes (hot water supply). For example, hot condensate at a pressure of 7 Bar contains approximately 720 kJ / kg of thermal energy. When the condensate is removed, part of it (about 300 kJ / kg) turns into secondary boiling steam, and part (about 420 kJ / kg) can be disposed of in the form of hot water. Ultimately, this will help not only save fuel or electricity (for heating cold make-up water, for the formation of secondary steam, for hot water supply), but also to simplify the technical solution of some technological or economic problems.
The condensate is essentially pure (practically distilled) water that does not require additional water treatment. Its return to the main working circuit of the steam-power or heat-exchange system will save: a) on the intake of raw water for the make-up system; b) at water treatment (purification and chemical treatment of water).
At the same time, devices - steam traps are only able to separate the condensate from the working steam, but they are not able to ensure the transportation of the disposed condensate over any considerable distance. Therefore, the collection and transportation (pumping) of water condensate from steam consumers (steam power machines and heat exchangers) is a separate important technical and economic task.
Purpose and composition of condensate pumping stations
Consumers of steam of steam power machines and heat exchange equipment, in which steam condensate is mainly formed, are sometimes located at considerable distances from steam generators or other consumers of return condensate water, for delivery to which it is required to organize its transportation. Like any liquid medium, hot steam condensate is transported to its consumers using hydraulic (water) pumps of various designs, adapted to operate at elevated temperatures of the pumped medium. In addition to the water pumps themselves, condensate pumping systems require a set of objective monitoring, safety and automation tools necessary to ensure their reliable, trouble-free and long-term operation in automatic mode.
Condensate pumping stations are, first of all, complex technical solutions designed for a specific (or typical) steam condensate drainage system, allowing to solve the problem of condensate drainage at a high engineering and technical level. Typically, such a station includes:
- receiver or condensate collection tank;
- a supporting frame for installing the station's components, ensuring its transportation;
- condensate (water) pump, or several such pumps, of one or another basic design;
- a set of pipeline fittings for organizing the connection of the pumping station to the pipeline system;
- a set of means for power supply (drive) of condensate pumps and automation of their work;
- set of necessary instrumentation instrumentation;
- complex of hydrostatic protection means: safety valves, bursting discs.
Varieties of condensate pumping stations
In practice, pumping stations of two main types are used to pump condensate from steam power machines and heat exchangers:
Based on electric pumps. The design of such a pumping station, as a rule, is based on a centrifugal (booster) water pump with a driving electric motor, as well as an electrical panel for power supply, automation and electrical protection. Due to the high performance of the centrifugal hydraulic pump, its operation requires the introduction of a buffer collection tank for condensate into the system, and its automatic on / off float type. Transfer stations based on electric pumps are technically simple, economical and relatively inexpensive. Their work is not associated with partial extraction of working steam, and a decrease in its parameters. But at the same time, the reliability of their operation critically depends on the uninterrupted supply of electricity, therefore their use is impractical in emergency-hazardous conditions and systems, as well as those that ensure the operation of critical technological processes. Also, high temperature electric pumps are more expensive.
Rice. Multistage electric pump for a condensate pumping station.
Based on mechanical pumps . They, as a rule, are steam condensate pumps operating on the principle of cyclic displacement (into the outlet pipeline) of portions of condensate by the pressure of the working steam. According to the pump principle. In this case, partial extraction of working steam is carried out directly from the working circuit of the steam consumer.
The design of a mechanical condensate pump has a high degree of automation and autonomy in operation, makes it possible to do without the supply of electricity at all, and does not depend on the reliability (continuity) of its supply. As long as the supply of working steam, necessary to displace the condensate pressure, will be maintained at the proper level, its indicators will be maintained, until then, mechanical condensate pumps will operate in automatic mode. But at the same time, such a design of a pumping station is characterized by greater technical complexity, requires more numerous regulating, guiding and control valve automatics, and is also associated with partial extraction of working steam.
Rice. Yoshitake mechanical condensate pump for condensate pumping unit.
Scopes of condensate pumping stations
Condensate pumping stations are an integral part of the systems for making up steam power machines and heat exchangers with water. They are used to ensure efficient and economical operation:
- power generating steam and gas and steam power plants (in condensers of steam turbines);
- industrial heat exchangers: fuel oil heaters TES, desalination plants, distillation units, etc .;
- steam heating systems;
- autoclaves, combi steamers in the food industry;
- technological drums in the paper industry;
- pumping liquids similar to condensate in viscosity and chemical activity (based on electric pumps).
Selection parameters for condensate pumping unit
Condensate pumping stations are designed for specific operating conditions of steam power machines and heat exchange equipment. The defining parameters for their design (selection) are:
- performance of the drainage system, in cubic meters / hour of condensate;
- condensate temperature in the supply (suction) line;
- condensate pressure in the supply line;
- back pressure in the delivery line;
- range of condensate pumping, total hydraulic resistance of the transport pipeline;
- operating steam parameters (for mechanical steam condensate pumps).
Condensate pumping stations of OPEKS Energosystems
Using all the accumulated experience in the production of high-quality heat exchange and other heating equipment, OPEKS Energosystems has established the design and manufacture of condensate pumping stations of its own production, both on the basis of electrical and mechanical condensate pumps. OPEKS Energysystems condensate pumping stations are distinguished by the consistently high quality of design and manufacture that is characteristic of any product of our company.
They can be professionally designed and installed by our company for any existing condensate drainage system:
- for the specific conditions of use of both electric and steam mechanical pumps;
- by productivity, pressure, temperature of the medium;
- by the distance of transportation (pumping) of condensate.
We are able to manufacture not only high-quality industrial heat exchangers, but also a variety of related and auxiliary equipment, including condensate pumping stations, to ensure their efficient and economical operation. OPEKS Energysystems condensate pumping stations are above all a technically reliable means of achieving resource savings in the field of steam condensate systems. This is equipment that very quickly reaches the payback level, and in the future only brings net profit.