RU2812625C1 - Batch-type vacuum deaerator for heating and hot water systems (two embodiments) - Google Patents

Abstract

FIELD: thermal power engineering.

SUBSTANCE: invention can be used to remove gases from feed water of the heating and hot water supply systems. According to the first variant, a periodic vacuum deaerator of a heating and hot water supply system includes a control system, deaeration chamber 1, in the upper part of which there is nozzle 2 for spraying the source water, valve 3 for water supply to the nozzle and gas release valve 4, and water low-level sensor 5 at the bottom, outlet pipe 6 connected to the inlet of pump 7 and check valve 8 connected to the outlet of pump 7. Water high-level sensor 9 is additionally installed in the upper part of deaeration chamber 1, and deaeration start sensor 10 is installed under nozzle 2 for spraying the source water. Behind check valve 8 there is outlet pipe 11 with valve 12 for displacing the vapour-gas mixture, the outlet of which is connected to the lower part of deaeration chamber 1. According to variant 2, in the upper part of deaeration chamber 1 the following are additionally installed: water high-level sensor 9 and a valve to prevent the release of water, and under the nozzle 2 for spraying the source water there is sensor 10 for the start of deaeration. Behind check valve 8 an outlet pipe is mounted with a valve for displacing the vapour-gas mixture, the outlet of which is connected to the inlet pipe of the water emission prevention valve, and a downpipe is connected to the outlet pipe of the water emission prevention valve, the open end of which is located above the bottom of deaeration chamber 1.

EFFECT: improving the quality of deaeration and productivity without increasing the size, weight and energy consumption for a deaerator with both a low flow rate of water flow and an increased flow rate of water flow, for the possibility of using the deaerator in block-modular and small boiler houses.

7 cl, 2 dwg

Description

The invention relates to thermal power engineering and can be used to remove gases from feed water of heating and hot water supply systems.

A vacuum deaerator of periodic action is used in hot water boiler houses, where there is no steam and atmospheric deaerators operating using steam, to prevent corrosion of power equipment by removing corrosive gases from the water

A vacuum deaerator of periodic action is known (RU 2194671, class C02F 1/20, C02F 103/02, 2002), containing a deaerator with a pipe for supplying deaerated water to a curved surface and pipes for removing the vapor-gas phase and deaerated water. The device is equipped with a mechanism for changing the volume of the deaerator in the form of a membrane with a rigid center, a storage unit made integral with the deaerator. The deaerated water supply pipe is equipped with an inlet valve, and each of the outlet pipes is also equipped with an outlet valve. The mechanism for changing the volume of the deaerator and the outlet valve of the vapor-gas phase removal pipe are connected to the drive with the ability to synchronize their operation.

The principle of operation of the known deaerator is based on periodic changes in its internal volume. This is necessary to create a vacuum by increasing the volume at the time of the deaeration stage, followed by a decrease in the internal volume and carrying out the stage of first displacing the released gases into the atmosphere through the gas release valve, and after that, displacing the deaerated water to the consumer through the deaerated water outlet valve under excess pressure.

The disadvantage of this vacuum deaerator is the technical difficulty of changing the internal volume of the deaerator necessary to obtain a good vacuum. As the area and stroke of the membrane with a rigid center increases, the force loads on the rigid center drive mechanism increase significantly, especially to create sufficient excess pressure to supply deaerated water to the consumer. This design leads to an increase in the weight of the installation and energy consumption. In addition, the resulting vacuum value is not enough to deaerate water without heating.

A known vacuum deaerator for periodic operation of a heating and hot water supply system (RU 2793025, class F24D 3/02, 2023) includes a control system, a deaeration chamber, in the upper part of which there is a nozzle for spraying source water, a water supply valve to the nozzle and an outlet valve gases, and below, a low water level sensor, an outlet pipe connected to the pump and a check valve. In the upper part of the deaeration chamber, at a level from 0.1 to 0.5 of its height from the top, a sensor for the start of deaeration is additionally installed, and behind the pump there is an additional membrane expansion tank for storing deaerated water to displace the vapor-gas mixture, behind which there is a check valve connected to pipelines for supplying treated water to the consumer.

The disadvantage of the known design is its bulkiness, due to the fact that to carry out the displacement cycle, a membrane expansion tank of a supply of deaerated water is required to displace the vapor-gas mixture, which takes up a significant amount of space. The useful volume of deaerated water that can be used for displacement in a membrane tank is 50-60% of the total volume of the membrane tank, and this limitation is associated with the use of a membrane that requires certain conditions for long-term operation. Accordingly, the total volume of the membrane tank must be, with the necessary margin, at least 2 times larger than the volume of the deaeration chamber, which significantly increases the dimensions and weight of the deaerator and creates difficulties for use in small-sized block-modular boiler houses.

A vacuum deaerator was selected as a prototype (Operation Manual SI1456ru_9125393_Servitec_Sonderanlage.pdf), including a deaeration chamber in the form of a vacuum spray pipe with an internal volume of 40 to 104 dm ³ , a pump, a nozzle for spraying source water in the deaerator chamber, a water supply valve to the nozzle, a shut-off fittings, a gas release valve, a low water level sensor in the deaeration chamber, an outlet pipe connected to the pump inlet and a check valve connected to the pump outlet, as well as a control system.

The principle of operation of the installation is based on the fact that when water is pumped out from the deaeration chamber by a pump in an amount exceeding the volume of water supplied for deaeration, a rarefaction zone is formed above the surface of the water in the deaeration chamber and when the initial heated water is injected through the nozzle, dissolved gases and steam are released. Water after the pump is supplied to the consumer through the main line. In the initial state, the deaeration chamber and pump are filled with water, the water supply valve to the nozzle is closed.

The disadvantages of the known installation are the low quality of deaerated water due to the fact that at the stage of releasing the vapor-gas mixture, gases are displaced by non-deaerated water, which remains in the deaeration chamber until the start of the next deaeration cycle and reaches the consumer, and also due to the short residence time of drops of atomized water in a vacuum, especially at the beginning of the deaeration cycle, due to which some of the dissolved gases do not have time to release. This leads to the fact that the amount of oxygen removed from the deaerated water is less than 90% of what was available, i.e. more than 10% of dissolved oxygen remains in deaerated water and reaches the consumer, causing corrosive destruction of equipment and heating networks. Insufficient quality of deaeration during one passage of water through the deaeration chamber forces the constant flow of network water for additional deaeration, which increases energy costs.

The problem to be solved by the invention is the creation of a vacuum deaerator of periodic action for heating and hot water supply systems, the use of which eliminates the disadvantages of vacuum deaerators of existing designs.

The technical result of the invention is to improve the quality of deaeration without increasing weight, dimensions and energy consumption and a general increase in productivity due to the elimination of additional deaeration as a periodic deaerator for heating and hot water supply systems with low productivity in the first option, and with high productivity in the second option, for the possibility of its use in block-modular and small boiler houses.

The posed problem and the stated technical result are achieved due to the fact that according to the first option, a periodic vacuum deaerator of a heating and hot water supply system includes a control system, a deaeration chamber, in the upper part of which a nozzle is installed for spraying source water, a water supply valve to the nozzle and a valve release of gases, and at the bottom there is a low water level sensor, an outlet pipe connected to the pump inlet and a check valve connected to the pump outlet . According to the invention, an upper water level sensor is additionally installed in the upper part of the deaeration chamber, and a deaeration start sensor is installed under the nozzle for spraying the source water. Behind the check valve, an outlet pipe is mounted with a valve for displacing the vapor-gas mixture, the outlet of which is connected to the lower part of the deaeration chamber or the outlet pipe of the deaeration chamber.

According to the second option, a periodic vacuum deaerator for a heating and hot water supply system includes a control system, a deaeration chamber, in the upper part of which there is a nozzle for spraying the source water, a water supply valve to the nozzle and a gas release valve, and at the bottom a low water level sensor, an outlet pipe, connected to the pump inlet and a check valve connected to the pump outlet. According to the invention, in the upper part of the deaeration chamber there is additionally installed a sensor for the upper water level and a valve to prevent the release of water, and under the nozzle for spraying the source water there is a sensor for the start of deaeration. Behind the check valve, an outlet pipe with a valve for displacing the vapor-gas mixture is mounted, the outlet of which is connected to the inlet pipe of the water emission prevention valve, and a downpipe is connected to the outlet pipe of the water emission prevention valve, the open end of which is located above the bottom of the deaeration chamber.

According to the first and second options, the deaeration start sensor installed under the nozzle is preferably located at a level from 0.1 to 0.5 of the chamber height. This location of the deaeration start sensor is due to the fact that for high-quality deaeration a sufficient vacuum volume must be provided for water spraying. When the deaeration start sensor is located less than 0.1 height from the top of the deaeration chamber, water jets will almost immediately enter either the water or the wall of the deaeration chamber and will not have time to release dissolved oxygen. The location of the deaeration start sensor at a distance from the top of more than 0.5 of the height of the deaeration chamber is impractical, because further increase does not affect the quality, but significantly reduces the performance of the deaerator.

The required number of nozzles for spraying source water is calculated using the formula N=Q _d /q _f , where:

N - number of nozzles;

Q _d - deaerator productivity l/min;

q _f - productivity of one nozzle l/min.

Nozzles for spraying source water are located above the deaeration start sensor and directed upward to create conditions for better atomization and longer residence of water droplets in the vacuum volume.

A valve for adjusting the gas displacement rate is additionally installed on the outlet pipe to reduce the rate of displacement of the vapor-gas mixture to a safe value at which the upper level sensor together with the vapor-gas mixture displacement valve will have time to stop the supply of water from the heating network and prevent water hammer at the end of displacement and the release of water from the gas release valve .

An additional check valve is installed between the outlet pipe of the deaerated water and the pump inlet to prevent air leakage through the pump shaft seal at the beginning of the displacement cycle.

The presence of an upper water level sensor allows you to promptly stop the supply of water for displacement, signal the end of gas displacement and, if necessary, immediately begin the next deaeration cycle, which eliminates downtime and increases the maximum productivity of the deaerator.

The presence of a deaeration start sensor in the deaeration chamber ensures that the process of deaeration of the source water entering through the nozzle begins only when the necessary conditions for good deaeration are created. The location of the deaeration start sensor under the nozzle creates conditions for supplying atomized water only into the created vacuum volume of the deaeration chamber, which significantly improves the quality of deaerated water.

In both options, the presence on the outlet pipe of a valve for adjusting the speed of displacement of the vapor-gas mixture, together with the valve for displacing the vapor-gas mixture, allows displacement in the cycle of displacement of the vapor-gas mixture at the optimal speed, depending on the size of the deaerator and the selected operating mode.

According to the first option, the presence of an outlet pipe with a vapor-gas mixture displacement valve mounted behind a check valve located behind the pump allows the vapor-gas mixture to be displaced from the deaeration chamber by deaerated water from the heating network, which, after the water displacement valve, is supplied to the lower part of the deaeration chamber. This connection of the outlet pipe is intended for a periodic deaerator of small capacity with a correspondingly low rate of displacement of the vapor-gas mixture, because For more complete displacement of the vapor-gas mixture, water must rise as much as possible in the deaeration chamber and at high displacement speeds, due to the technological variation in the response of the upper level sensor and the valve for displacement of the vapor-gas mixture, water hammers and the release of water through the gas release valve may occur, which is unacceptable.

According to the second option, for deaerators with increased productivity, connecting the outlet pipe to the inlet pipe of the water emission prevention valve, and the presence of a downpipe connected to the outlet pipe of the water emission prevention valve, the open end of which is located above the bottom of the deaeration chamber, also allows for the displacement of steam-gas mixtures from the deaeration chamber with deaerated water from the heating network. In this case, water from the heating network after the water emission prevention valve is supplied through a lowering pipe down the deaeration chamber without mixing with the vapor-gas mixture, which improves the quality of deaerated water when displaced. The use of a mechanical quick-acting valve to prevent the release of water, through which water is supplied for displacement, provides additional protection against water hammer and water release through the gas release valve and allows displacement at high speed, which is important for high-capacity deaerators, otherwise the cycle of displacement of the vapor-gas mixture will be too long and will reduce the overall performance of the deaerator.

The invention is illustrated by drawings, where Fig. 1 shows a general view of a periodic vacuum deaerator according to the first embodiment; in fig. 2 - second warrant of a vacuum deaerator of periodic action.

In the drawing the positions indicate:

1 - deaeration chamber;

2 - nozzle for spraying source water;

3 - water supply valve to nozzle 2;

4 - gas release valve;

5 - low water level sensor;

6- outlet pipe;

7 - pump;

8 - check valve;

9 - upper level sensor;

10 - deaeration start sensor;

11 - outlet pipe, the outlet of which is connected to the bottom of the deaeration chamber 1;

12 - valve for displacing the vapor-gas mixture;

13 - valve for adjusting the speed of displacement of the vapor-gas mixture on the outlet pipe 11;

14 - additional check valve installed between the outlet pipe 6 and the pump 7;

15 - valve to prevent water release;

16 - outlet pipe, the outlet of which is connected to the inlet pipe of the valve 15 to prevent the release of water;

17 - downpipe connected to the outlet pipe of the valve 15 to prevent the release of water;

18 - open end of the lower pipe 17, located above the bottom of the deaeration chamber 1;

19 valve for displacing the vapor-gas mixture on the outlet pipe 16

20 - valve for adjusting the speed of displacement of the vapor-gas mixture on the outlet pipe 16.

A periodic vacuum deaerator works as follows.

In the first version, in the initial state, the deaeration chamber 1 and pump 7 are filled with water. Valve 3 for supplying source water to nozzle 2 is closed. The unit is in standby mode. When the control system (not shown in Fig. 1) receives a signal, for example, from a pressure sensor in the heating main (not shown in Fig. 1), about a decrease in pressure, the control system turns on the pump 7, which, through the outlet pipe 6 and the check valve 8, starts pump out water from deaeration chamber 1. A deep vacuum is created in the upper part of deaeration chamber 1 (-0.9-0.95 bar for cold water, taking into account the weight of a water column more than 1 m high in the deaeration chamber) and enhanced vaporization begins. The rarefied vapors allow the pump to gradually pump out water and the water level decreases. When the water level drops below the deaeration start sensor 10, it is triggered, and the control system opens valve 3 for supplying source water to nozzle 2. Sprayed jets of water enter the vacuum volume of deaeration chamber 1, and the process of vacuum deaeration begins. Pump 7 continues pumping deaerated water from deaeration chamber 1, while pump 7 immediately supplies deaerated water to the consumer through check valve 8, which increases the performance of the deaerator. A sufficiently deep vacuum is maintained in the deaeration chamber 1, gases and vapors are released, and the water level in the deaeration chamber 1 continues to gradually decrease. When the water level in the deaeration chamber 1 becomes low, the low water level sensor 5 is triggered and the control system closes the valve 3 supplying source water to the nozzle 2 and turns off the pump 7. A deep vacuum is maintained in the deaeration chamber 1, and the check valve 14 at the inlet of the pump 7 prevents air leakage through the pump shaft seal 7 into deaeration chamber 1. The deaeration cycle is completed. At the beginning of the cycle of displacement of the vapor-gas mixture, the control system opens the valve 12 for displacing the vapor-gas mixture and deaerated water from the heating and hot water supply system through the outlet pipe 11 and through the valve 13 for adjusting the displacement speed enters the lower part of the deaeration chamber 1, displacing the vapor-gas mixture. When water fills the deaeration chamber 1, the upper level sensor 9 will operate, which will send a signal to the control system about the end of the gas and vapor removal cycle. After which the control system will close valve 12 for displacing the vapor-gas mixture. Because it takes a certain time to create a signal by the upper level sensor 9 and to work out turning off the water supply by valve 12 for displacing the vapor-gas mixture, and the water level at the end of displacement should be as high as possible, with valve 13 of the displacement speed it is necessary to select a small displacement speed in order to avoid the release of water through the valve 4 of gas release and the appearance of water hammer, accordingly, the displacement time increases and the productivity of the deaerator in the first option cannot be high. But for small boiler houses with little make-up it is enough. The intermittent vacuum deaerator is in its initial state and is waiting for a signal to turn on again.

Work according to the second option, for a periodic deaerator of a heating and hot water supply system with an increased water flow rate, is carried out as follows.

The water deaeration cycle is carried out similarly to option 1. At the beginning of the cycle of displacement of the vapor-gas mixture, the control system opens the displacement valve 19 and deaerated water from the heating and hot water supply system through the outlet pipe 16 and through the valve 20 for adjusting the displacement speed enters the inlet pipe of the valve 15 to prevent the release of water, and from the outlet pipe through the downpipe 17 through the open end 18 located above the bottom of the deaeration chamber 1 it enters its lower part, displacing the vapor-gas mixture. When water fills the deaeration chamber 1, the upper level sensor 9 will operate, which will send a signal to the control system about the end of the gas and vapor removal cycle, after which the control system will close the valve 19 for displacing the vapor-gas mixture. The use of a fast-acting mechanical valve 15 to prevent the release of water, through which water is supplied for displacement, provides additional protection against water hammer and the release of water through the gas release valve 4 and allows displacement at high speed, which is important for high-capacity deaerators, otherwise the cycle of displacement of the vapor-gas mixture will be too long and will reduce the overall performance of the deaerator.

The use of the claimed technical solution makes it possible to improve the quality of deaeration without increasing the dimensions, metal consumption and energy consumption of a periodic vacuum deaerator for heating and hot water supply systems and, in general, to increase the productivity of a periodic vacuum deaerator with both low water consumption and high consumption, which is important for modular and small boiler houses.

Claims (10)

1. Vacuum deaerator of periodic operation of a heating and hot water supply system, including a control system, a deaeration chamber, in the upper part of which there is a nozzle for spraying the source water, a water supply valve to the nozzle and a gas release valve, and at the bottom - a low water level sensor, an outlet pipe , connected to the pump inlet, and a check valve connected to the pump outlet, characterized in that an upper water level sensor is additionally installed in the upper part of the deaeration chamber, and a deaeration start sensor is installed under the nozzle for spraying source water, while a discharge valve is mounted behind the check valve a pipe with a valve for displacing the vapor-gas mixture, the outlet of which is connected to the bottom of the deaeration chamber. 2. Vacuum deaerator of periodic operation of a heating and hot water supply system, including a control system, a deaeration chamber, in the upper part of which there is a nozzle for spraying the source water, a water supply valve to the nozzle and a gas release valve, and at the bottom - a low water level sensor, an outlet pipe , connected to the pump inlet, and a check valve connected to the pump outlet, characterized in that in the upper part of the deaeration chamber an upper water level sensor and a water emission prevention valve are additionally installed, and under the nozzle for spraying the source water - a deaeration start sensor, while behind the check valve there is mounted an outlet pipe with a valve for displacing the vapor-gas mixture, the outlet of which is connected to the inlet pipe of the water emission prevention valve, and a downpipe is connected to the outlet pipe of the water emission prevention valve, the open end of which is located above the bottom of the deaeration chamber. 3. Vacuum deaerator according to claim 1 or 2, characterized in that the deaeration start sensor installed under the nozzle is located at a level from 0.1 to 0.5 of the chamber height. 4. Vacuum deaerator according to claim 1 or 2, characterized in that it is equipped with additional nozzles for spraying the source water, and the number of nozzles for spraying the source water is calculated by the formula N=Q _d /q _f , where: N - number of nozzles; Q _d - deaerator productivity, l/min; q _f - productivity of one nozzle, l/min. 5. Vacuum deaerator according to claim 1 or 2, characterized in that the nozzles for spraying the source water are located above the deaeration start sensor and directed upward. 6. Vacuum deaerator according to claim 1 or 2, characterized in that a valve for adjusting the rate of gas displacement is additionally installed on the outlet pipe. 7. Vacuum deaerator according to claim 1 or 2, characterized in that an additional check valve is installed between the outlet pipe of the deaerated water and the pump inlet.

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