SUBATMOSPHERIC HEATING SYSTEM

Abstract

A subatmospheric heating system refers to the field of heat power, namely energy-saving technologies and is designed for autonomous heating of residential, public, industrial buildings and greenhouses, livestock farms, etc.

For highly efficient transfer of heat flow from the heat energy source, a vacuum-steam method of heat transfer is used in an environment with adjustable depth of dilution with separate condensate return and vacuuming devices, with the possibility of mounting the heat point in either the basement, floor and roof variants. The reliability of the system is ensured by its safe and uninterrupted operation, and in the case of an unsatisfactory level of airtightness of the system (to eliminate leakages).

The energy efficiency of a subatmospheric heating system is achieved by a high rate of heat transfer and a minimum consumption of electricity by periodically operating pumps, while the efficiency of the system is 88% with energy savings of up to 40%

Claims

1. A subatmospheric heating system with the transfer of heat flow by vacuum-steam method, a system comprising: a steam production unit, a heating system, a condensate return device, a device for vacuuming and qualitative regulation of the steam temperature by the depth of vacuum, which differs in that the condensate return device and the vacuuming device operate independently and in a periodic mode.

2. The system according to claim 1 differs in that the steam production unit is equipped with an automatic control blocking unit of energy supply, a level transmitter column with conductometric sensors for monitoring the level of the intermediate coolant, an indicator of the control level of the pumping condensate pump, an automatic control system for the operation of the vacuum water ring pump.

Description

[0011] FIGURE shows a diagram of a subatmospheric heating system with parallel devices for condensate return to the boiler and vacuum system.

[0012] A subatmospheric heating system consists (see FIGURE) of: steam production units, condensate return devices to the boiler, vacuum devices and quality control of the steam temperature by the depth of the vacuum and the heating system of the premises.

[0013] Steam production unit includes: steam boiler 1, equipped with a water column 2 with conductometric sensors of the upper and lower level of the intermediate coolant in the boiler, a water indicator 3, a safety valve 4, a steam supply valve to the heating system of premises 5, a valve 6, a valve for filling the steam boiler with an intermediate coolant (softened water, ethylene glycolantifreeze) 7, a plug valve 40; automatic control and blocking system of energy supply, comprising: a pressure switch (PS) automation unit (A) to control the operation of the Executive mechanism of the executing machine (M), a means for visual inspection of pressurerarefaction (PG), level switch (CA).

[0014] The condensate return device to the boiler includes: condensate collection tank 18, equipped with a water indicator 19 and an air removal valve when filling the tank with an intermediate coolant 37, a valve for pre-filling the tank with an intermediate coolant 20, a water supply valve to the condensate pump 21, a centrifugal type condensate pump 22 with an ejector device, a pressure pipeline 23 and a return valve 24.

[0015] The device for vacuuming and quality control of the steam temperature includes vacuum water ring pump (WRP) 25, 36 valve for supplying water to the WRP for the formation of a water ring, a pipeline for removing air from the system 26 through a condensate tank, a pipeline for removing air 27 into the air separator, a pipeline for removing air 32 from the air separator, a pipeline for supplying water to the WRP 39, the air-purge drum, which includes the tank of the air-purge drum 28, a valve 33 for supplying water in WRP, the valve 34 for pre-filling the air-purge drum with water, water indicator 29, the valve 38 for venting the tank of air-purge drum when filling with water, return valve 30, solenoid valve 31 in the position of normally closed and the pipeline of removal of air in the atmosphere 32, the automation unit (A) managing operation of WRP, depending on the set parameters of the desired dilution.

[0016] The premises heating system includes: distribution steam pipe 8, the valves of vacuumed steam supply 9, the vertical raising steam pipes 10, a valve 35 for emptying vertical steam distribution pipeline (if necessary), the valves of adjusting the steam flow 12 to the heaters 11 (registers, radiators, etc.), vertical condensate lines 13, cut-off valves 14, a Central condensate line 15 and installed dirty tank 16, grid filter 17 and electric-contact pressure gauge (PGS) to control the vacuum in the system and transmit signals to the control unit WRP.

[0017] It should be particularly noted that in order to achieve a satisfactory level of airtightness of the entire system, after installation, a mandatory test of each device for leakage of 99% of air +1% helium by the injection pressure of 0.6 MPa should be carried out. Monitoring of leakages is to be done by a helium leakage detector.

[0018] A subatmospheric heating system works the following way: valves 6, 7, 20, 34, 35, 36 and plug valve 40 to set in the Closed position, valves 5, 9, 12, 14, 21, 33, 37 and 38 to set in the Open position.

[0019] Attach to the valve 7 a flexible pipe of the calibrated capacity (in FIGURE conditionally not shown) with an intermediate coolant (softened water or antifreeze), set the valve in the Open position, fill the steam boiler with water to the upper level of the water space of the boiler by the water indicator 3, then set the valve in the Closed position, disconnect the pipe, and set the valve 6 in the Open position.

[0020] Attach the flexible pipe of the calibrated container with an intermediate coolant to the valve 20 of the condensate collection tank 18, set the valve in the Open position, refuel with water to the nominal operating level by the water indicator 19, set the position of the valves 20, 37 in the Closed position, after refueling, disconnect the flexible pipe.

[0021] Attach the flexible pipe of the calibrated container with the intermediate coolant to the valve 34, fill the tank of the air separator 28 with water to the nominal working level on the water indicator 29, after filling, set the valves 34, 38 to the Closed position and disconnect the pipe, and set the valve 36 to the Open position to fill WRP with water.

[0022] Set on the electric-contact pressure gauge (PGS) the range of the required vacuum level, with a decrease in the vacuum (in the case of leakages), the WRP is turned on to restore the specified range, while the solenoid valve 31 is set to the Open position and the pumped air through the pipelines 26, 27 and 32 is removed to the atmosphere, and when the required level of vacuum is reached, the WRP is turned off. The system is initially vacuumed to an absolute pressure of 0.03 MPa with a vacuum depth of 0.07 MPa when this vacuum is reached, the WRP is disengaged, and the solenoid valve is set to the Closed position, with a decrease in the vacuum to 0.01 MPa, the vacuum water ring pump is automatically activated (with satisfactory airtightness) the pump onoff period is 80100 min. Setting different in depth ranges of vacuum on an electric-contact pressure gauge (PGS) makes quality control of the steam temperature possible.

[0023] Simultaneously with starting the vacuum system, set the plug valve 40 to the Open position for supplying energy, start the burner device of the steam boiler with an automatic control and block unit of energy supply, which reacts to signals from the pressure switch (PS)when the absolute pressure inside the steam space of the boiler reaches 0.1 MPa, the automation unit reduces the energy supply to achieve the steam pressure to the working, nominal absolute pressure of 0.08 MPa at which the steam temperature is 93 C., thereby producing a Central quantitative regulation of the steam temperature. At the termination, for any reasons of the energy carrier supply the automatic equipment of the boiler blocks sudden repeated supply of the energy carrier, thereby providing explosion safety and reliability of operation of the steam boiler.

[0024] When the lower or upper operating levels of the intermediate coolant in the boiler are reached, the conductometric sensors of the level transmitter column 2 give electrical signals to the level switch (CA), which in turn controls the operation of the pumping condensate pump 22 (on or off), in this case the pump operation mode is periodic.

[0025] Thus, the periodic operation of both the WRP and the pumping condensate pump leads to significant savings in electrical energy.

[0026] The speed of molar heat transfer by vacuum steam reaches 80 m/s and more, as well as an absolute pressure not exceeding 0.09 MPa, which ensures high efficiency of heat energy transfer from the boiler to heating devices with low metal quantity per unit and increased heat transfer coefficients in heated rooms.

[0027] A feature of this heating system is that it is divided into independently operating from each other device of the condensate return and vacuum device with automatic control to create different values of rarefaction, which allows to produce quality regulation of temperature in the system with a broad range of depth of vacuum of 0.01 MPa to 0.07 MPa, a temperature difference of the coolant in this case is from 96 C. to 68 C., which corresponds to the sanitary normshygienic requirements, as well as this temperature difference allows the use of plastic and polyethylene pipes, pipe fittings made of plastic materials subject to the least degree of corrosion.

[0028] Application in the heating system of the premises of the scheme with the upper distribution of steam, with the passing movement of steam and condensate, provides silent passage of steam at high speed, there is no need for the use of steam traps, while the heat transfer coefficient is much higher compared to traditional systems of water and atmospheric steam heating.

[0029] Thermal analysis of the industrial prototype showed that the efficiency of this subatmospheric heating system reaches 88%, with energy savings ranging from 38% to 40%.

[0030] The heating system is easy to maintain, safe to operate and provides reliable, uninterrupted operation of heat supply.