An indirect air-cooled tower with coupled finned wall type thermal storage box and its performance control method

Abstract

This invention relates to an indirect air-cooled tower with coupled finned-wall thermal storage tanks and a performance control method. The invention comprises a conventional air-cooled tower and multiple parallel finned-wall thermal storage tanks arranged in a fan-blade pattern within the tower. Each storage tank contains multiple cylindrical phase-change thermal storage tanks connected in series. Louvers are installed on the outer surface of the finned-wall thermal storage tanks to control their air permeability. When the unit back pressure exceeds a set value, the louvers of the finned-wall thermal storage tanks are opened, heating the air inside the tower through convection heat exchange between the thermal storage tanks and the air, thereby improving the ventilation and heat dissipation of the air-cooled tower. This invention fully utilizes the unused space inside the indirect air-cooled tower, reduces the cost of the thermal storage tanks' insulation layer through the tower's shielding and insulation properties, and improves the ventilation and heat dissipation performance of the air-cooled tower in two ways: firstly, the finned-wall thermal storage tank layout provides a windproof structure to improve the aerodynamic field inside the tower; secondly, the louvers control the air permeability of the finned-wall thermal storage tanks, increasing and regulating the airflow temperature inside the tower.

Description

Technical Field

[0001] This invention relates to the field of air-cooled power plant technology, and in particular to an indirect air-cooled tower with a coupled finned wall type thermal storage box and a method for performance control. Background Technology

[0002] With the large-scale grid connection of unstable new energy power plants, thermal power will steadily develop into a regulating power source to adapt to the fluctuations in power system demand, continuously playing a "ballast" role. my country's energy structure of abundant coal and scarce gas, and the distribution of regional resources rich in coal and poor in water, have made large-scale air-cooled coal-fired power generating units the main force of thermal power. With the continuous penetration of new energy sources, they also undertake greater and more arduous tasks of ensuring power supply.

[0003] Indirect air-cooled systems that rely on natural ventilation from the tower have been widely used in large thermal power units in my country due to their low power consumption, low noise, and relatively high economic efficiency and reliability. Because they use ambient air as the cooling medium, the heat dissipation efficiency of indirect air-cooled systems is highly sensitive to environmental factors. High ambient temperatures and strong winds can adversely affect airflow inside and outside the indirect air-cooled tower and heat exchange in the radiators.

[0004] To address this problem, this invention proposes an indirect air-cooled tower with a coupled finned-wall thermal storage tank and a performance control method. Integrating the finned-wall thermal storage tank into the indirect air-cooled unit improves the unit's load regulation range, and arranging it within the indirect air-cooled tower reduces the land area required for energy storage. Furthermore, utilizing the structural and layout characteristics of the finned-wall thermal storage tank effectively enhances the cooling capacity of the indirect air-cooled tower under harsh conditions of high temperature and strong winds. This invention effectively improves the economy and safety of indirect air-cooled units operating in harsh environments. Summary of the Invention

[0005] The purpose of this invention is to reduce the impact of the environment on the ventilation and heat dissipation performance of the indirect air-cooled tower, reduce heat loss of the heat storage box, improve the turbulent flow field inside the indirect air-cooled tower under the influence of crosswinds, and enhance the heat exchange effect of the air-cooled radiator under the influence of high temperature. Therefore, an indirect air-cooled tower with coupled finned wall type heat storage box and a performance control method are proposed.

[0006] The technical solution of the present invention is an indirect air-cooled tower with a coupled finned wall type thermal storage box, including a tower body, and a thermal storage box for peak shaving is provided inside the tower body.

[0007] The number of thermal storage tanks is set by the user, and the thermal storage tanks are evenly arranged in a fan-blade shape.

[0008] The heat storage tanks arranged inside the tower are connected in parallel via tubes.

[0009] If four sets of thermal storage tanks are installed, the entire thermal storage tank will be arranged in a cross shape.

[0010] If eight sets of thermal storage tanks are installed, the entire thermal storage tanks will be arranged in a star-shaped pattern.

[0011] Preferably, the heat storage box is a finned wall type;

[0012] The heat storage box contains multiple heat storage tanks arranged side by side; the heat storage tanks are cylindrical, and multiple heat storage tanks are connected in series inside the heat storage box to form the heat storage tank tube side;

[0013] The shell side of the thermal storage tank is equipped with low-temperature phase change thermal storage material, while the tube side of the thermal storage tank is filled with steam or water, and the connecting tubes are finned serpentine tubes; the low-temperature phase change thermal storage material refers to a material with a phase change temperature below 300℃.

[0014] The outer surface of the thermal storage box is equipped with operable louvers.

[0015] Preferably, during the thermal storage period, the inlet of each thermal storage tank is connected to the first parallel header and then to the steam inlet header, through which heat source steam is introduced and extracted through the low-pressure cylinder; the outlet of each thermal storage tank is connected to the second parallel header and then to the steam outlet header, which is connected to the condenser.

[0016] Preferably, during the heat release period, the inlet of the heat storage tank is connected to the second parallel header and then to the inlet header, through which condensate is introduced; the outlet of the heat storage tank is connected to the first parallel header and then to the outlet header, which is connected to the deaerator.

[0017] Preferably, a first regulating valve is provided between the steam inlet header and the low-pressure cylinder, and a first check valve is provided between the steam outlet header and the condenser; a second regulating valve is provided between the water inlet header and the condensate pump, and a second check valve is provided between the water outlet header and the deaerator.

[0018] Preferably, during heat storage or heat release, the circulating cooling water is driven by a circulating water pump into the condenser to absorb the waste heat from the exhaust steam and then discharged into the environment through the indirect air-cooled tower.

[0019] A performance control method for an indirect air-cooled tower with a coupled finned wall type thermal storage box is applied to the indirect air-cooled tower as described above, including peak heat release operation mode, off-peak thermal storage operation mode and conventional operation mode.

[0020] S1, Peak Heat Release Operation Mode: When the unit is operating at high load, if the unit load N>N1, back pressure p>p1, and after a delay of t1, the second regulating valve and the second check valve are opened. The condensate pump pressurized the condensate into multiple heat storage tanks, which are heated by the phase change material inside the heat storage tanks and then enter the deaerator. At the same time, the louvers on the outer surface of the heat storage tanks are opened, and the air inside the heat storage tank heating tower is heated. The opening degree of the louvers on the outer surface of the heat storage tanks can be set as a function of the back pressure bias p-p1. The cumulative heat storage time τ2 is reset to zero, and the cumulative heat release time τ1 is started. If τ1>X, the second regulating valve and the second check valve are closed.

[0021] S2. The low - valley heat storage operation mode is as follows: when the unit is operating at low load, if the unit load N < N2 and after a delay of t2, open the first regulating valve and the first check valve. The extraction steam from the low - pressure cylinder enters multiple heat storage boxes, is cooled by the phase - change material in the heat storage tank, and then is discharged into the condenser. At this time, the shutters on the outer surface of the heat storage box are in the closed state; the cumulative heat - release time τ1 is cleared, and the cumulative heat - storage time τ2 is timed. If τ2 > Y, close the first regulating valve and the first check valve;

[0022] S3. The normal operation mode is: during other operation times except for the peak - heat - release operation mode and the low - valley heat - storage operation mode, close the first regulating valve, the second regulating valve, the first check valve and the second check valve, and close the shutters on the outer surface of the heat storage box.

[0023] Among them, N1, N2, p1, t1, t2, X, Y are set by the user according to the actual operation conditions of the power station, and τ1 and τ2 are initialized to 0. N1 is the peak - operation load threshold; N2 is the low - valley - operation load threshold; p1 is the upper limit of the back pressure during peak operation; t1 is the duration for meeting the peak - operation determination; t2 is the duration for meeting the low - valley - operation determination; τ1 is the cumulative heat - storage duration; τ2 is the cumulative heat - release duration; X is the heat - release time limit; Y is the heat - storage time limit.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The present invention consists of a traditional air - cooled tower body and multiple parallel fin - wall - type heat storage boxes uniformly arranged in a fan - blade shape inside the tower; inside the fin - wall - type heat storage box, there are multiple cylindrical phase - change heat storage tanks connected in series. Shutters are installed on the outer surface of the fin - wall - type heat storage box to control the ventilation degree; when the back pressure of the unit is higher than the set value, open the shutters of the fin - wall - type heat storage box, and heat the air inside the tower through the convection heat transfer between the heat storage tank and the air, thereby enhancing the ventilation and heat dissipation of the air - cooled tower driven by buoyancy.

[0026] The present invention makes full use of the idle space inside the indirect air - cooled tower. On the one hand, it integrates and converts the heat storage tanks into fin - wall - type heat storage boxes, and the layout is a wind - proof structure to improve the air - dynamic field inside the tower, enhancing the ventilation and heat - dissipation performance of the air - cooled tower; on the other hand, through the shielding and heat - preservation effect of the air - cooled tower, it reduces the self - insulation layer of the heat storage tank and related costs. By controlling the ventilation degree of the fin - wall - type heat storage box with shutters, it improves and adjusts the air - flow temperature inside the tower, thereby further enhancing and adjusting the ventilation and heat - dissipation performance of the indirect air - cooled tower.

[0027] The present invention arranges the heat storage tanks used for peak - load regulation in the form of fin - wall boxes inside the indirect air - cooled tower. While realizing the peak - load regulation of the unit, it makes full use of the space inside the tower; the structure, layout and function of multiple fin - wall boxes can effectively improve the cooling capacity of the indirect air - cooled tower under high - temperature and strong - wind conditions, and improve the economy and safety of the unit operation. Brief Description of the Drawings

[0028] Figure 1 A schematic diagram of an indirect air-cooled tower with a coupled finned wall type thermal storage box;

[0029] Figure 2 This is a schematic diagram of the interior of a wing-wall type thermal storage box;

[0030] Figure 3 Schematic diagram of louvers on the outer surface of a wing-wall type thermal storage box;

[0031] Figure 4 This is a schematic diagram showing the connection between the finned-wall type thermal storage tank and the generator unit.

[0032] Reference numerals in the attached drawings: 1. Tower body; 2. Heat storage tank body; 3. Heat storage tank; 4. Heat storage tank tube side; 5. Heat storage tank shell side; 6. Louver; 7. Low-pressure cylinder; 8. Condenser; 9. Condensate pump; 10. Circulating water pump; 11. First regulating valve; 12. First check valve; 13. Steam inlet header; 14. Steam outlet header; 15. Water inlet header; 16. Water outlet header; 17. Second regulating valve; 18. Second check valve; 19. Deaerator; 20. First parallel header; 21. Second parallel header. Detailed Implementation

[0033] Example 1

[0034] like Figure 1 As shown, in this embodiment, the finned heat storage box 2 is coupled inside the indirect air-cooled tower. The number of heat storage boxes 2 is set by the user, and the heat storage boxes 2 are evenly arranged in a fan-blade shape.

[0035] The heat storage tanks 2 arranged inside the tower body 1 are connected in parallel through tubes.

[0036] If four sets of thermal storage boxes 2 are installed, the entire thermal storage box 2 will be arranged in a cross shape.

[0037] If eight sets of thermal storage tanks 2 are installed, the entire thermal storage tank 2 will be arranged in a star-shaped pattern.

[0038] like Figure 2 As shown, the heat storage box 2 contains multiple heat storage tanks 3 arranged side by side; the heat storage tanks 3 are cylindrical, and multiple heat storage tanks 3 are connected in series in the heat storage box 2 to form the heat storage tank tube 4.

[0039] Low-temperature phase change thermal storage material is arranged in the shell side 5 of the thermal storage tank, and steam or water flows inside the tube side 4 of the thermal storage tank. The tubes used for connection are finned serpentine tubes.

[0040] The outer surface of the thermal storage box 2 is equipped with operable louvers 6.

[0041] like Figure 4As shown in the figure, during heat storage, the inlets of the heat storage boxes 2 are all connected to the first parallel header 20 and then to the steam inlet header 13. The heat source steam is introduced from the steam inlet header 13, and the steam is extracted from the low-pressure cylinder 7. The outlets of the heat storage boxes 2 are all connected to the second parallel header 21 and then to the steam outlet header 14. The steam outlet header 14 is connected to the condenser 8.

[0042] During heat release, the inlets of the heat storage boxes 2 are all connected to the second parallel header 21 and then to the condensate inlet header 15. The condensate is introduced from the condensate inlet header 15. The outlets of the heat storage boxes 2 are all connected to the first parallel header 20 and then to the condensate outlet header 16. The condensate outlet header 16 is connected to the deaerator 19.

[0043] A first regulating valve 11 is provided between the steam inlet header 13 and the low-pressure cylinder 7, and a first check valve 12 is provided between the steam outlet header 14 and the condenser 8. A second regulating valve 17 is provided between the condensate inlet header 15 and the condensate pump 9, and a second check valve 18 is provided between the condensate outlet header 16 and the deaerator 19.

[0044] During heat storage or heat release, the circulating cooling water is driven by the circulating water pump 10 to enter the condenser 8 to absorb the waste heat of the exhaust steam and then discharge the waste heat to the environment in the indirect air cooling tower body 1.

[0045] A performance regulation method for an indirect air cooling tower with a coupled fin wall type heat storage box is applied to the indirect air cooling tower as described above, including a peak heat release operation mode, a valley heat storage operation mode, and a normal operation mode.

[0046] S1. Peak heat release operation mode: When the unit is operating at a high load, if the unit load N > N1, the back pressure p > p1, and after a delay of t1 time, open the second regulating valve 17 and the second check valve 18. The condensate pressurized by the condensate pump 9 enters the multiple heat storage boxes 2, is heated by the phase change material in the heat storage tank 3, and then enters the deaerator 19. At the same time, the shutters 6 on the outer surface of the heat storage box 2 are opened, and the heat storage tank 3 heats the air in the tower. The opening degree of the shutters 6 on the outer surface of the heat storage box 2 can be set as a functional relationship with the back pressure offset p - p1. The cumulative heat storage time τ2 is cleared, and the cumulative heat release time τ1 is timed. If τ1 > X, close the second regulating valve 17 and the second check valve 18.

[0047] S2. Valley heat storage operation mode: When the unit is operating at a low load, if the unit load N < N2 and after a delay of t2 time, open the first regulating valve 11 and the first check valve 12. The steam extracted from the low-pressure cylinder 7 enters the multiple heat storage boxes 2, is cooled by the phase change material in the heat storage tank 3, and then is discharged into the condenser 8. At this time, the shutters 6 on the outer surface of the heat storage box 2 are in the closed state. The cumulative heat release time τ1 is cleared, and the cumulative heat storage time τ2 is timed. If τ2 > Y, close the first regulating valve 11 and the first check valve 12.

[0048] S3. The normal operating mode is as follows: during other operating times except for peak heat release mode and off-peak heat storage mode, the first regulating valve 11, the second regulating valve 17, the first check valve 12 and the second check valve 18 are closed, and the louvers 6 on the outer surface of the heat storage box 2 are closed.

[0049] Among them, N1, N2, p1, t1, t2, X, and Y are set by the user according to the actual operation of the power plant, and τ1 and τ2 are initialized to 0. N1 is the peak operation load threshold; N2 is the off-peak operation load threshold; p1 is the peak operation back pressure limit; t1 is the duration of meeting the peak operation judgment; t2 is the duration of meeting the off-peak operation judgment; τ1 is the cumulative duration of heat storage; τ2 is the cumulative duration of heat release; X is the heat release time limit; and Y is the heat storage time limit.

[0050] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for performance control of an indirect air-cooled tower with a coupled finned wall type thermal storage box, comprising a tower body (1), characterized in that, Inside the tower body (1), there is a heat storage box body (2) for peak shaving; A plurality of heat storage box bodies (2) are evenly arranged in a fan blade shape; on the outer surface of the heat storage box body (2), a switchable louver (6) is configured; The heat storage box bodies (2) arranged inside the tower body (1) are connected in parallel through the tube side; During heat storage, the inlets of the heat storage box bodies (2) are all connected to the first parallel header (20) and then connected to the steam inlet header (13), and the heat source steam is introduced from the steam inlet header (13), and the steam is extracted by the low-pressure cylinder (7); the outlets of the heat storage box bodies (2) are all connected to the second parallel header (21) and then connected to the steam outlet header (14), and the steam outlet header (14) is connected to the condenser (8); During heat release, the inlets of the heat storage box bodies (2) are all connected to the second parallel header (21) and then connected to the condensate inlet header (15), and the condensate is introduced from the condensate inlet header (15); the outlets of the heat storage box bodies (2) are all connected to the first parallel header (20) and then connected to the condensate outlet header (16), and the condensate outlet header (16) is connected to the deaerator (19); A first regulating valve (11) is provided between the steam inlet header (13) and the low-pressure cylinder (7), and a first check valve (12) is provided between the steam outlet header (14) and the condenser (8); a second regulating valve (17) is provided between the condensate inlet header (15) and the condensate pump (9), and a second check valve (18) is provided between the condensate outlet header (16) and the deaerator (19); during heat storage or heat release, the circulating cooling water is driven by the circulating water pump (10) to enter the condenser (8) to absorb the waste heat of the exhausted steam and then discharge the waste heat to the environment in the indirect air cooling tower body (1); The air cooling tower further includes a peak heat release operation mode, a low valley heat storage operation mode, and a normal operation mode; S1. Peak heat release operation mode: When the unit is operating at a high load, if the unit load N > N1, the back pressure p > p1, and after a delay of t1 time, the second regulating valve (17) and the second check valve (18) are opened, and the condensate pressurized by the condensate pump (9) enters multiple heat storage box bodies (2), is heated by the phase change material in the heat storage tank (3) and then enters the deaerator (19). At the same time, the louver (6) on the outer surface of the heat storage box body (2) is opened, and the heat storage tank (3) heats the air in the tower; the opening degree of the louver (6) on the outer surface of the heat storage box body (2) can be set as a functional relationship with the back pressure offset p - p1; the cumulative heat storage time τ2 is cleared, and the cumulative heat release time τ1 is timed. If τ1 > X, the second regulating valve (17) and the second check valve (18) are closed; S2. Low valley heat storage operation mode: When the unit is operating at a low load, if the unit load N < N2 and after a delay of t2 time, the first regulating valve (11) and the first check valve (12) are opened, and the steam extracted by the low-pressure cylinder (7) enters multiple heat storage box bodies (2), is cooled by the phase change material in the heat storage tank (3) and then discharged into the condenser (8). At this time, the louver (6) on the outer surface of the heat storage box body (2) is in the closed state; the cumulative heat release time τ1 is cleared, and the cumulative heat storage time τ2 is timed. If τ2 > Y, the first regulating valve (11) and the first check valve (12) are closed; S3. The normal operating mode is: during other operating times except for peak heat release mode and low-valley heat storage mode, the first regulating valve (11), the second regulating valve (17), the first check valve (12) and the second check valve (18) are closed, and the louvers (6) on the outer surface of the heat storage box (2) are closed. Among them, N1, N2, p1, t1, t2, X, and Y are set by the user according to the actual operation of the power plant, and τ1 and τ2 are initialized to 0; where N1 is the peak operation load threshold; N2 is the off-peak operation load threshold; p1 is the peak operation back pressure limit; t1 is the duration of meeting the peak operation judgment; t2 is the duration of meeting the off-peak operation judgment; τ1 is the cumulative duration of heat storage; τ2 is the cumulative duration of heat release; X is the heat release time limit; and Y is the heat storage time limit.

2. The performance control method for an indirect air-cooled tower with a coupled finned wall type thermal storage box according to claim 1, characterized in that, The heat storage box (2) is set in four groups, and the four groups of heat storage boxes (2) are arranged in a cross shape.

3. The performance control method for an indirect air-cooled tower with a coupled finned wall type thermal storage box according to claim 1, characterized in that, Eight sets of heat storage boxes (2) are set up, and the eight sets of heat storage boxes (2) are arranged in a cross shape.

4. The performance control method for an indirect air-cooled tower with a coupled finned wall type thermal storage box according to claim 1, characterized in that, The heat storage box (2) is a wing-wall type; The heat storage box (2) contains multiple heat storage tanks (3) arranged side by side; the heat storage tanks (3) are cylindrical, and the multiple heat storage tanks (3) inside the heat storage box (2) are connected in series to form the heat storage tank tube (4). The shell side (5) of the thermal storage tank is filled with low-temperature phase change thermal storage material, and the tube side (4) of the thermal storage tank is filled with steam or water. The tubes used for connection are finned serpentine tubes.

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