A boiler economizer control system and control method thereof

Abstract

The present invention discloses a boiler economizer control system, including a flash evaporator; the boiler economizers are respectively arranged in the kiln tail waste heat boiler and the kiln head waste heat boiler; the outlets of the flash evaporator are respectively connected to the economizer inlets of the kiln tail waste heat boiler and the kiln head waste heat boiler; the economizer outlet of the kiln tail waste heat boiler is connected to the flash evaporator; the economizer outlet of the kiln head waste heat boiler is respectively connected to the inlet of the flash evaporator and the economizer inlet of the kiln tail waste heat boiler. By adopting the above technical scheme, according to the production process requirements, through this system, the boiler outlet flue gas temperature can be freely switched between two different temperature values. Under the premise of not changing the boiler outlet steam pressure, by reasonably designing the economizer area, the boiler outlet flue gas adjustment temperature difference can reach 50°C or above, meeting the production process requirements for the boiler outlet flue gas temperature, and improving the system thermal utilization rate as much as possible.

Description

Technical Field

[0001] The present invention belongs to the technical field of boiler temperature control. More specifically, the present invention relates to a boiler economizer control system. The present invention also relates to a control method of the control system. Background Art

[0002] In the prior art, the adjustable space of the flue gas temperature at the boiler outlet is small, and the flue gas temperature at the boiler outlet cannot be changed within a large range according to the production process requirements. At the same time, the thermal energy utilization rate cannot be improved, resulting in energy waste. Summary of the invention

[0003] The present invention provides a boiler economizer control system, the purpose of which is to meet the requirements of production process for boiler outlet flue gas temperature control.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The boiler economizer control system of the present invention includes a flash evaporator; the boiler economizers are respectively arranged in the kiln tail waste heat boiler and the kiln head waste heat boiler; the hot water outlet of the flash evaporator is respectively connected to the economizer inlets of the kiln tail waste heat boiler and the kiln head waste heat boiler; the economizer outlet of the kiln tail waste heat boiler is connected to the flash evaporator; the economizer outlet of the kiln head waste heat boiler is respectively connected to the inlet of the flash evaporator and the economizer inlet of the kiln tail waste heat boiler.

[0006] An electric regulating valve is arranged at the kiln tail end on the pipeline connecting the hot water outlet of the flash evaporator and the economizer inlet of the kiln tail waste heat boiler; an electric regulating valve is arranged at the kiln head end on the pipeline connecting the economizer outlet of the kiln head waste heat boiler and the economizer inlet of the kiln tail waste heat boiler.

[0007] A boiler feed water pump is arranged on the main pipeline connecting the hot water outlet of the flash evaporator with the economizer inlets of the kiln tail waste heat boiler and the kiln head waste heat boiler.

[0008] The flash evaporator is provided with a condensate inlet and a flash evaporator steam outlet.

[0009] Alternatively, the flash evaporator is replaced by a deaerator; the steam outlet of the flash evaporator is replaced by a steam exhaust port of the deaerator.

[0010] In order to achieve the same invention purpose as the above technical solution, the present invention also provides a control method of the boiler economizer control system described above, and its technical solution is:

[0011] When the electric regulating valve at the kiln head is opened and the electric regulating valve at the kiln tail is closed, the boiler feed water pump is heated by the economizer of the kiln head waste heat boiler and then enters the economizer of the kiln tail waste heat boiler; at this time, the inlet feed water temperature of the kiln tail waste heat boiler economizer is relatively high, which can achieve a relatively high flue gas temperature at the outlet of the kiln tail waste heat boiler;

[0012] When the electric regulating valve at the kiln head is closed and the electric regulating valve at the kiln tail is opened, the boiler feed water provided by the boiler feed water pump does not pass through the kiln head waste heat boiler, but directly enters the economizer of the kiln tail waste heat boiler. Since the feed water temperature of the kiln tail waste heat boiler is low, the flue gas temperature at the flue gas outlet of the kiln tail waste heat boiler can be lower.

[0013] By adjusting the combination of different opening degrees of the electric regulating valve at the kiln head and the electric regulating valve at the kiln tail, the flue gas outlet temperature of the waste heat boiler at the kiln tail can be stably operated at a certain point in a larger temperature range.

[0014] The present invention adopts the above-mentioned technical scheme. According to the production process requirements, through this system, the boiler outlet flue gas temperature can be freely switched between two different temperature values ​​(or a certain intermediate temperature). Under the premise of not changing the boiler outlet steam pressure, by reasonably designing the economizer area, the difference adjustment range of the boiler outlet flue gas temperature can reach 50°C and above, meeting the production process requirements for the boiler outlet flue gas temperature and maximizing the system thermal utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The contents shown in the attached drawings and the symbols in the drawings are briefly described as follows:

[0016] Figure 1 It is a schematic diagram of the structure of the present invention.

[0017] The markings in the figure are:

[0018] 1. Boiler feed water pump, 2. Waste heat boiler at the kiln tail, 3. Waste heat boiler at the kiln head, 4. Flash evaporator, 5. Electric regulating valve at the kiln head, 6. Electric regulating valve at the kiln tail, 7. Condensate inlet, 8. Flash evaporator steam outlet. DETAILED DESCRIPTION

[0019] The specific implementation modes of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0020] like Figure 1 The structure of the present invention is a boiler economizer control system, including a flash evaporator 4; the boiler economizers are respectively arranged in the kiln tail waste heat boiler 2 and the kiln head waste heat boiler 3.

[0021] In order to solve the problems existing in the prior art and overcome its defects, and to achieve the invention purpose of satisfying the requirements of the production process for the control of the flue gas temperature at the boiler outlet, the technical solution adopted by the present invention is:

[0022] like Figure 1 As shown, in the boiler economizer control system of the present invention, the hot water outlet of the flash evaporator 4 is connected to the economizer inlets of the kiln tail waste heat boiler 2 and the kiln head waste heat boiler 3 respectively; the economizer outlet of the kiln tail waste heat boiler 2 is connected to the flash evaporator 4; the economizer outlet of the kiln head waste heat boiler 3 is respectively connected to the inlet of the flash evaporator 4 and the economizer inlet of the kiln tail waste heat boiler 2.

[0023] By adopting the control system of the present invention, it is possible to switch the flue gas temperatures at different outlets of the boiler body, adapt to the production process requirements, and improve the thermal utilization rate of the system.

[0024] A kiln tail electric regulating valve 6 is arranged on the pipeline connecting the outlet of the flash evaporator 4 and the economizer inlet of the kiln tail waste heat boiler 2; a kiln head electric regulating valve 5 is arranged on the pipeline connecting the economizer outlet of the kiln head waste heat boiler 3 and the economizer inlet of the kiln tail waste heat boiler 2.

[0025] The working principle of the present invention is: by adjusting the switches of the electric regulating valve 5 and the electric regulating valve 6, different inlet feed water temperatures of the economizer of the kiln tail waste heat boiler 2 are achieved, thereby achieving different outlet flue gas temperatures of the kiln tail waste heat boiler 2.

[0026] A boiler feed water pump 1 is arranged on the main pipeline connecting the hot water outlet of the flash evaporator 4 with the economizer inlets of the kiln tail waste heat boiler 2 and the kiln head waste heat boiler 3.

[0027] The boiler feed water pump 1 provides circulation power for the high-temperature hot water generated by the flash evaporator 4, and provides high-temperature hot water to the kiln tail waste heat boiler 2 and the kiln head waste heat boiler 3 respectively.

[0028] The flash evaporator 4 is provided with a condensate inlet 7 and a flash evaporator steam outlet 8 .

[0029] The condensate inlet 7 and the flash evaporator steam outlet 8 realize the circulation of system water supply and steam.

[0030] Another embodiment of the present invention:

[0031] The flash evaporator 4 described in the above embodiment is replaced by a deaerator; and the flash evaporator steam outlet 8 is replaced by a deaerator exhaust port.

[0032] According to the production process requirements, by operating the control system, the boiler outlet flue gas temperature can be freely switched between two different temperature values. Without changing the boiler outlet steam pressure, by reasonably designing the economizer area, the boiler outlet flue gas adjustment temperature difference adjustment range can reach 50°C and above, meeting the production process requirements for the boiler outlet flue gas temperature and maximizing the system thermal utilization rate.

[0033] In order to achieve the same invention purpose as the above technical solution, the present invention also provides a control method for the boiler economizer control system described above, and its specific technical solution is:

[0034] When the electric regulating valve 5 at the kiln head is opened and the electric regulating valve 6 at the kiln tail is closed, the boiler feed water pump 1 is heated by the economizer of the kiln head waste heat boiler 3 and then enters the economizer of the kiln tail waste heat boiler 2; at this time, the inlet feed water temperature of the economizer of the kiln tail waste heat boiler 2 is relatively high, so that the flue gas temperature at the outlet of the kiln tail waste heat boiler 2 can be relatively high;

[0035] When the electric regulating valve 5 at the kiln head is closed and the electric regulating valve 6 at the kiln tail is opened, the boiler feed water provided by the boiler feed water pump 1 directly enters the economizer of the kiln tail waste heat boiler 2 without passing through the kiln head waste heat boiler 3. Since the feed water temperature of the kiln tail waste heat boiler 2 is low, the flue gas temperature at the flue gas outlet of the kiln tail waste heat boiler 2 can be made lower.

[0036] By adjusting the combination of different opening degrees of the kiln head electric regulating valve 5 and the kiln tail electric regulating valve 6, the flue gas outlet temperature of the kiln tail waste heat boiler 2 can be stably operated at a certain point temperature within a larger temperature range.

[0037] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A boiler economizer control system, comprising a flash evaporator (4); the boiler economizers are respectively arranged in a kiln tail waste heat boiler (2) and a kiln head waste heat boiler (3), characterized in that: The hot water outlet of the flash evaporator (4) is respectively connected to the economizer inlet of the kiln tail waste heat boiler (2) and the kiln head waste heat boiler (3); the economizer outlet of the kiln tail waste heat boiler (2) is connected to the flash evaporator (4); the economizer outlet of the kiln head waste heat boiler (3) is respectively connected to the inlet of the flash evaporator (4) and the economizer inlet of the kiln tail waste heat boiler (2); a kiln tail electric regulating valve (6) is arranged on the pipeline connecting the hot water outlet of the flash evaporator (4) and the economizer inlet of the kiln tail waste heat boiler (2); a kiln head electric regulating valve (5) is arranged on the pipeline connecting the economizer outlet of the kiln head waste heat boiler (3) and the economizer inlet of the kiln tail waste heat boiler (2); a boiler feed water pump (1) is arranged on the main pipeline connecting the hot water outlet of the flash evaporator (4) and the economizer inlets of the kiln tail waste heat boiler (2) and the kiln head waste heat boiler (3).

2. The boiler economizer control system according to claim 1, characterized in that: The flash evaporator (4) is provided with a condensate inlet (7) and a flash evaporator steam outlet (8).

3. The boiler economizer control system according to claim 1, characterized in that: The flash evaporator (4) is replaced by a deaerator.

4. The boiler economizer control system according to claim 2, characterized in that: The flash evaporator (4) is replaced by a deaerator; the flash evaporator steam outlet (8) is replaced by a deaerator steam exhaust port.

5. The control method of a boiler economizer control system according to any one of claims 1 to 4, characterized in that: When the electric regulating valve (5) at the kiln head is opened and the electric regulating valve (6) at the kiln tail is closed, the boiler feed water pump (1) is heated by the economizer of the kiln head waste heat boiler (3) and then enters the economizer of the kiln tail waste heat boiler (2); at this time, the inlet feed water temperature of the economizer of the kiln tail waste heat boiler (2) is relatively high, so that the flue gas temperature at the outlet of the kiln tail waste heat boiler (2) can be relatively high; When the kiln head electric regulating valve (5) is closed and the kiln tail electric regulating valve (6) is opened, the boiler feed water provided by the boiler feed water pump (1) does not pass through the kiln head waste heat boiler (3) but directly enters the economizer of the kiln tail waste heat boiler (2). Since the feed water temperature of the kiln tail waste heat boiler (2) is low, the flue gas temperature at the flue gas outlet of the kiln tail waste heat boiler (2) can be lower.

6. The control method of the boiler economizer control system according to claim 5, characterized in that: By adjusting the combination of different opening degrees of the kiln head electric regulating valve (5) and the kiln tail electric regulating valve (6), the flue gas outlet temperature of the kiln tail waste heat boiler (2) can be stably operated at a certain point temperature within a larger temperature range.

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