Combined heat and power generation energy cascade heat supply module and system
By combining cogeneration energy cascade heating modules with steam cascade heating and heat storage devices for high back-pressure coal-fired generator sets and coal-fired generator sets with cylinder cut-off modifications, the problem of increased coal consumption for heating during peak-shaving operation of coal-fired generator sets has been solved, achieving a balance between the economy and flexibility of the heating system.
Patent Information
- Application Number
- CN202423022466.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-12-09
AI Technical Summary
In existing technologies, there is a contradiction between the flexibility and economy of heating in coal-fired power units, which leads to increased coal consumption for heating during peak-shaving operation and makes it impossible to balance the flexibility and economy of heating.
A combined heat and power (CHP) energy cascade heating module is provided. By connecting with high back pressure coal-fired generator sets and modified coal-fired generator sets, the module utilizes the steam discharged from the low-pressure cylinder and medium-pressure cylinder and reheat steam to cascade heat the return water of the heating network. Combined with a thermal storage device and a steam injection pipeline, the module optimizes the utilization of the return water of the heating network and improves the heating economy.
While ensuring the flexibility of heating supply, it reduces coal consumption for heating, improves the economy of the heating system, effectively utilizes the waste heat of low-grade exhaust steam, and reduces energy waste.
Smart Images
Figure CN223448471U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of thermal power generating unit heat supply, in particular to a heat and power cogeneration energy cascade heat supply module and a heat and power cogeneration energy cascade heat supply system. BACKGROUND
[0002] Under the background of double carbon target, when coal-fired generating units undertake heat supply tasks, they not only need to have flexible peak shaving capacity, but also need to fully exert the energy-saving advantages of large-scale heat and power cogeneration to improve the proportion of clean heat supply in society. The heat supply technologies currently used in the market generally have the contradiction between heat supply flexibility and economy: for example, low-energy heat supply technology, although it can effectively recover the low-grade exhaust steam of the unit, greatly improve the heat supply capacity and energy-saving benefits of the unit, but it has strong heat and power coupling and poor flexibility; the cylinder cutting heat supply technology represented by low-pressure cylinder micro-output, although it can effectively reduce the low-pressure cylinder steam intake and improve the intermediate discharge heat supply capacity and deep regulation capacity, but the heat supply steam source is still taken from the intermediate discharge extraction steam, and it does not have heat supply economy. Moreover, the cylinder cutting technology and high-low side heat supply technology only show that the unit's flexibility can be improved by increasing the unit's peak shaving depth, and they do not have the ability to improve the unit's peak output capacity.
[0003] Currently, in order to avoid not meeting the grid peak shaving requirements, the flexibility of heat supply is considered more than the economy of heat supply when implementing heat supply transformation, resulting in an increase in actual heat supply coal consumption under deep peak shaving, and some even exceed the heat supply energy consumption of decentralized coal-fired boilers, which does not meet the original intention of heat and power cogeneration replacing coal-fired boilers for heat supply and energy saving.
[0004] Therefore, there is an urgent need for a heat supply system that can balance heat supply flexibility and economy. SUMMARY
[0005] The purpose of the utility model embodiment is to provide a heat and power cogeneration energy cascade heat supply module and system, which solves the problem of increased heat supply coal consumption and reduced heat supply economy of coal-fired generating units during peak shaving operation due to the flexibility of multiple coal-fired generating units for heat supply in the prior art.
[0006] In order to achieve the above-mentioned purpose, the utility model provides a heat and power cogeneration energy cascade heat supply module, which is connected with a heat network system and a plurality of high-back-pressure coal-fired generating units and a plurality of cylinder cutting modified coal-fired generating units, the high-back-pressure coal-fired generating units and the cylinder cutting modified coal-fired generating units can supply reheated steam to the heat and power cogeneration energy cascade heat supply module, and the heat and power cogeneration energy cascade heat supply module comprises:
[0007] The first heat exchange device connected with the outlet of the heat supply network system is used for being connected with the exhaust port of the low-pressure cylinder of the at least one group of high-back pressure coal-fired generator units; the low exhaust steam discharged from the low-pressure cylinder of the high-back pressure coal-fired generator unit is used for preliminarily heating the heat supply network return water from the heat supply network system;
[0008] The first heating device connected with the heat exchange outlet of the first heat exchange device is used for being connected with the exhaust port of the intermediate-pressure cylinder of the at least one group of cylinder-cutting reconstruction coal-fired generator units; the intermediate exhaust steam discharged from the intermediate-pressure cylinder of the cylinder-cutting reconstruction coal-fired generator unit is used for secondarily heating the heat supply network return water discharged from the first heat exchange device to become the heat supply network supply water; and the heat supply network supply water is discharged from the heating outlet of the first heating device.
[0009] The steam supplement pipeline is used for supplying and feeding the reheated steam from the at least one group of high-back pressure coal-fired generator units and the at least one group of cylinder-cutting reconstruction coal-fired generator units to the first heating device; and the first heating device uses the reheated steam to heat the heat supply network return water discharged from the first heat exchange device to become the heat supply network supply water.
[0010] The heat storage device has a first storage part and a second storage part in communication; the first storage part is connected with the heating outlet of the first heating device and is used for recovering and storing the heat supply network supply water discharged from the first heating device; and the second storage part is connected with the heat exchange inlet of the first heat exchange device and is used for storing the cooled heat supply network supply water from the first storage part and feeding the cooled heat supply network supply water to the first heat exchange device as the heat supply network return water.
[0011] Specifically, the steam supplement pipeline comprises a steam supplement main pipeline and a plurality of steam supplement branch pipelines.
[0012] The steam supplement main pipeline has one steam outlet and a plurality of steam inlets; the steam outlet of the steam supplement main pipeline is connected with the steam inlet of the first heating device; the at least one group of high-back pressure coal-fired generator units is connected with one steam supplement branch pipeline; the at least one group of cylinder-cutting reconstruction coal-fired generator units is connected with another steam supplement branch pipeline; the reheated steam from the high-back pressure coal-fired generator units and the reheated steam from the cylinder-cutting reconstruction coal-fired generator units enter the steam supplement main pipeline through the corresponding steam supplement branch pipelines and then enter the first heating device through the steam supplement main pipeline.
[0013] Specifically, the water supply bypass pipeline is connected from the heat exchange outlet of the first heat exchange device to the heating outlet of the first heating device and is connected in parallel with the heat supply network inlet and outlet channel of the first heating device to form a water supply bypass channel.
[0014] Specifically, the water supply bypass control valve is arranged on the water supply bypass pipeline and is used for controlling the opening and closing of the water supply bypass channel.
[0015] Specifically, an inlet control valve is arranged on a connecting pipeline between the heat exchange outlet of the first heat exchange device and the heating inlet of the first heating device, for controlling the flow state of the heat network return water discharged from the first heat exchange device in the connecting pipeline between the heat exchange outlet of the first heat exchange device and the heating inlet of the first heating device.
[0016] Specifically, the system further comprises: a second heating device arranged between the heat exchange outlet of the first heat exchange device and the heating inlet of the first heating device, the second heating device being configured to heat the heat network return water discharged from the heat exchange outlet of the first heat exchange device by using the medium-pressure cylinder exhaust steam and the low-pressure cylinder exhaust steam of at least one high-back pressure coal-fired generator unit, and the heat network return water heated by the second heating device being sent into the first heating device.
[0017] Specifically, the system further comprises: a quality improving device connected to the steam inlet of the second heating device and the exhaust port of the medium-pressure cylinder and the exhaust port of the low-pressure cylinder of at least one high-back pressure coal-fired generator unit by pipelines, the quality improving device being configured to work under the drive of the medium-pressure cylinder exhaust steam of the high-back pressure coal-fired generator unit to improve the temperature and pressure of the low-pressure cylinder exhaust steam entering the second heating device.
[0018] Specifically, the system further comprises: a second heat exchange device connected to the exhaust port of the low-pressure cylinder of at least one high-back pressure coal-fired generator unit, for heating the heat network return water discharged from the first heat exchange device by using the low-pressure cylinder exhaust steam of the high-back pressure coal-fired generator unit connected thereto.
[0019] Specifically, the heat storage device is a heat storage tank.
[0020] The utility model discloses a kind of combined heat and power energy cascade heat supply systems, and the combined heat and power energy cascade heat supply system includes any one of the above-mentioned combined heat and power energy cascade heat supply module.
[0021] The cogeneration energy gradient heat supply module provided by the utility model, first heat exchange device and the exhaust port of the low-pressure cylinder of at least one high back pressure coal-fired generator set are connected, the low exhaust steam discharged by the exhaust port of the low-pressure cylinder of the high back pressure coal-fired generator set is used to exchange heat with the heat network return water from the heat network system to preliminarily heat the heat network return water, the preliminarily heated heat network return water is sent into the first heating device, the first heating device is connected with the exhaust port of the medium-pressure cylinder of at least one cylinder cutting and reforming coal-fired generator set, the medium exhaust steam discharged by the medium-pressure cylinder of the cylinder cutting and reforming coal-fired generator set is used to secondarily heat the heat network return water discharged from the first heat exchange device, the heat network return water after secondary heating is increased in temperature to become heat network supply water, meanwhile, the reheat steam of at least one high back pressure coal-fired generator set and at least one cylinder cutting and reforming coal-fired generator set can be supplemented to the first heating device through the steam supplement pipeline, the heat network return water is heated by the reheat steam to form the heat network supply water, the heat network supply water can be used for heat supply, the heat network supply water can also be sent into the first storage part of the heat storage device to be stored, the heat network supply water stored in the first storage part can also be supplied to the heat network system for heat supply, the second storage part can send the stored heat network supply water after temperature reduction to the first heat exchange device as the heat network return water.
[0022] Other features and advantages of the embodiments of the utility model will be described in detail in the following specific implementation part. ACCURATE DRAWINGS
[0023] The accompanying drawings are used to provide further understanding of the embodiments of the utility model, and constitute a part of the specification, and are used to explain the embodiments of the utility model together with the following specific implementation, but do not constitute the limitation to the embodiments of the utility model.In the drawings,
[0024] Figure 1 It is the layout schematic drawing of the cogeneration energy gradient heat supply module provided by the utility model embodiment;
[0025] Figure 2 It is the layout schematic drawing of the cogeneration energy gradient heat supply module provided by the utility model another embodiment;
[0026] Figure 3 is a layout schematic diagram of a combined heat and power energy cascade heat supply module provided by another embodiment of the present utility model.
[0027] Mark explanation
[0028] 3-steam supplement pipeline; 4-first heat exchange device; 5-first heating device; 51-inlet control valve; 6-heat storage device; 8-water supply bypass pipeline; 9-second heating device; 10-upgrading device; 11-second heat exchange device; 81-water supply bypass control valve; 100-high back pressure coal-fired generator set's intermediate pressure cylinder; 200-high back pressure coal-fired generator set's low pressure cylinder; 300-cylinder cutting reconstruction coal-fired generator set's intermediate pressure cylinder; 400-cylinder cutting reconstruction coal-fired generator set's low pressure cylinder. Specific implementation
[0029] The specific implementation of the embodiments of the present utility model is described in detail below in combination with the drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present utility model, and is not used to limit the embodiments of the present utility model.
[0030] Figure 1 is a layout schematic diagram of a combined heat and power energy cascade heat supply module; Figure 2 is a layout schematic diagram of another combined heat and power energy cascade heat supply module; Figure 3 is a layout schematic diagram of still another combined heat and power energy cascade heat supply module. As shown in Figures 1-3 the present utility model provides a combined heat and power energy cascade heat supply module, which is connected with a heat network system and connected with a plurality of high back pressure coal-fired generator sets and a plurality of cylinder cutting reconstruction coal-fired generator sets. The high back pressure coal-fired generator sets and the cylinder cutting reconstruction coal-fired generator sets can supply reheat steam to the combined heat and power energy cascade heat supply module. The combined heat and power energy cascade heat supply module comprises:
[0031] a first heat exchange device 4 connected with a water outlet of the heat network system, which is used to be connected with a steam outlet of a low pressure cylinder 200 of at least one high back pressure coal-fired generator set. The low exhaust steam discharged from the low pressure cylinder 200 of the high back pressure coal-fired generator set is used to preliminarily heat the heat network return water from the heat network system;
[0032] a first heating device 5 connected with a heat exchange water outlet of the first heat exchange device 4, which is used to be connected with a steam outlet of an intermediate pressure cylinder 300 of at least one cylinder cutting reconstruction coal-fired generator set. The intermediate exhaust steam discharged from the intermediate pressure cylinder 300 of the cylinder cutting reconstruction coal-fired generator set is used to secondarily heat the heat network return water discharged from the first heat exchange device 4 to become heat network supply water. The heat network supply water is discharged from a heating water outlet of the first heating device 5;
[0033] The steam supplement pipeline 3 is used for supplying the reheated steam from the at least one group of high back pressure coal-fired generator units and the at least one group of cylinder cut-over retrofit coal-fired generator units to the first heating device 5 through the steam supplement pipeline 3, and the first heating device 5 heats the heat supply water of the heat supply network by using the reheated steam.
[0034] The heat storage device 6 has a first storage part and a second storage part in communication, the first storage part is connected with the heating outlet of the first heating device 5, and is used for recovering and storing the heat supply water of the heat supply network discharged from the first heating device 5; the second storage part is connected with the heat exchange inlet of the first heat exchange device 4, and is used for storing the cooled heat supply water of the heat supply network from the first storage part, and conveying the cooled heat supply water of the heat supply network to the first heat exchange device 4 as the heat return water.
[0035] The cogeneration energy cascade heat supply module is connected with multiple high back pressure coal-fired generator units and multiple cylinder cutting reconstruction coal-fired generator units, each high back pressure coal-fired generator unit supplies reheat steam to the cogeneration energy cascade heat supply module through a high-low pressure bypass thereof, each cylinder cutting reconstruction coal-fired generator unit supplies reheat steam to the cogeneration energy cascade heat supply module through a high-low pressure bypass thereof, a first heat exchange device 4 and a first heating device 5 are arranged, and heat network return water is sequentially supplied into the first heat exchange device 4 and the first heating device 5; the first heat exchange device 4 is connected with a low-pressure cylinder exhaust port of at least one high back pressure coal-fired generator unit 200, the first heating device 5 is connected with a medium-pressure cylinder exhaust port of at least one cylinder cutting reconstruction coal-fired generator unit 300, heat network return water exchanges heat with low exhaust steam discharged from the low-pressure cylinder 200 of the high back pressure coal-fired generator unit connected therewith after entering the first heat exchange device 4, and the heat network return water absorbs the waste heat of the low exhaust steam of the low-pressure cylinder 200 of the high back pressure coal-fired generator unit, so that the heat network return water is preliminarily heated by the low exhaust steam; after the heat network return water is preliminarily heated, the heat network return water is discharged from the first heat exchange device 4 and then enters the first heating device 5, and the heat network return water discharged from the first heat exchange device 4 exchanges heat with medium exhaust steam discharged from the medium-pressure cylinder 300 of at least one cylinder cutting reconstruction coal-fired generator unit in the first heating device 5, so that the heat network return water absorbs the waste heat of the medium exhaust steam of the medium-pressure cylinder 300 of the cylinder cutting reconstruction coal-fired generator unit again; in addition to being supplied to the first heating device 5, the medium exhaust steam of the medium-pressure cylinder 300 of the cylinder cutting reconstruction coal-fired generator unit is also supplied to a low-pressure cylinder 400 of the cylinder cutting reconstruction coal-fired generator unit to drive the low-pressure cylinder 400 to work, and the heat network return water is secondarily heated by the medium exhaust steam to be heated to become heat network supply water; the first storage part of the heat storage device 6 can store the heat network supply water, that is, store heat energy, so that energy waste is avoided; then, the heat network supply water stored in the first storage part can be supplied into a heat network system for heat supply; the second storage part of the heat storage device 6 stores cold water and the heat network supply water after being cooled, when the heat storage device 6 releases heat, the cold water and the heat network supply water after being cooled stored in the second storage part are supplied into the first heat exchange device 4 and the first heating device 5 again to be heated, the cold water and the heat network supply water after being cooled are heated again as heat network return water, energy consumption is saved, and the problem that heat supply coal consumption increases when coal-fired generator units are in peak regulation operation due to flexibility of realizing linkage heat supply of multiple coal-fired generator units in the prior art is solved, and heat supply economy is improved.
[0036] In one embodiment, as shown in Figure 1 The steam supplement pipeline 3 includes a steam supplement main pipeline 31 and multiple steam supplement branch pipelines 32.
[0037] The steam supplement main line 31 has one steam outlet and multiple steam inlets, the steam outlet of the steam supplement main line 31 is connected with the steam inlet of the first heating device 5, at least one group of high back pressure coal-fired generator units is connected with one steam supplement branch line 32, at least one group of cylinder cut-over modified coal-fired generator units is connected with another steam supplement branch line 32, the reheated steam from the high back pressure coal-fired generator units and the reheated steam from the cylinder cut-over modified coal-fired generator units enter the steam supplement main line 31 through the corresponding steam supplement branch line 32, and then enter the first heating device 5 through the steam supplement main line 31.
[0038] The high back pressure coal-fired generator units supply reheated steam to the cogeneration energy cascade heat supply module through the high-low pressure bypass, the cylinder cut-over modified coal-fired generator units supply reheated steam to the cogeneration energy cascade heat supply module through the high-low pressure bypass, the high-low pressure bypass of the high back pressure coal-fired generator units supplies reheated steam to the steam supplement main line 31 through one steam supplement branch line 32, the reheated steam of the cylinder cut-over modified coal-fired generator units supplies reheated steam to the steam supplement main line 31 through another steam supplement branch line 32, the reheated steam from the high back pressure coal-fired generator units and the reheated steam from the cylinder cut-over modified coal-fired generator units enter the first heating device 5 after being combined in the steam supplement main line 31.
[0039] The module further comprises a water supply bypass pipeline 8 connected from the heat exchange outlet of the first heat exchange device 4 to the heating water outlet of the first heating device 5, and the water supply bypass pipeline 8 and the heat supply pipeline of the first heating device 5 form a water supply bypass channel in parallel.
[0040] A water supply bypass control valve 81 is arranged on the water supply bypass pipeline 8, and is used for controlling the opening and closing of the water supply bypass channel.
[0041] The heat network return water flows through the first heat exchange device 4 and the first heating device 5 in turn, the first heat exchange device 4 is a condenser, and the first heating device 5 is a peak heater. The first heat exchange device 4 extracts low-pressure exhaust steam of the low-pressure cylinder 200 of at least one group of high-backpressure coal-fired generator units and exchanges heat with the heat network return water. The heat network return water absorbs the waste heat of the low-grade exhaust steam, and then enters the first heating device 5. The first heating device 5 can extract medium-pressure exhaust steam of the medium-pressure cylinder 300 of at least one group of cut-cylinder modified coal-fired generator units and exchange heat with the heat network return water discharged from the first heat exchange device 4. The heat network return water absorbs the heat of the medium-pressure exhaust steam again, so that the heat network return water is heated again to become heat network supply water to supply heat externally. The first heating device 5 can also exchange heat with the heat network return water discharged from the first heat exchange device 4 through the reheat steam delivered through the steam supplement pipeline 3, so as to increase the temperature of the heat network return water. The supply water bypass pipeline 8 is connected with the heat exchange outlet of the first heat exchange device 4 and the heating outlet of the first heating device 5. In this way, when the temperature of the heat network return water heated by the first heat exchange device 4 can reach the temperature of the heat network supply water, the heat network return water discharged from the first heat exchange device 4 can flow through the supply water bypass pipeline 8 and then enter the heat network system to supply heat or be stored in the first storage part of the heat storage device 6, so as to avoid the heat network return water discharged from the first heat exchange device 4 from flowing through the first heating device 5 again and causing waste. The supply water bypass control valve 81 is arranged on the supply water bypass pipeline 8 to control the opening and closing of the supply water bypass pipeline 8, that is, to control the flow state of the heat network return water discharged from the first heat exchange device 4 in the supply water bypass pipeline 8. As shown in FIG. 1, the inlet control valve 51 is arranged at the heating inlet of the first heating device 5 to control the flow state of the heat network return water discharged from the first heat exchange device 4 in the connecting pipeline between the heat exchange outlet of the first heat exchange device 4 and the heating inlet of the first heating device 5. Figures 1-3
[0042] In another embodiment, as shown in FIG. 2, the module further comprises a second heating device 9 arranged between the heat exchange outlet of the first heat exchange device 4 and the heating inlet of the first heating device 5. The second heating device 9 uses the low-pressure exhaust steam discharged from the low-pressure cylinder 200 of at least one group of high-backpressure coal-fired generator units to assist in heating the heat network return water discharged from the heat exchange outlet of the first heat exchange device 4. The heat network return water assisted by the second heating device 9 is sent to the first heating device 5. Figure 2
[0043] The module further comprises a quality improvement device 10 connected with the steam inlet of the second heating device 9 and the steam outlets of the medium-pressure cylinder 100 and the low-pressure cylinder 200 of at least one group of high-backpressure coal-fired generator units through pipelines. The quality improvement device 10 works under the drive of the medium-pressure exhaust steam discharged from the medium-pressure cylinder 100 of the high-backpressure coal-fired generator unit to increase the temperature and pressure of the low-pressure exhaust steam entering the second heating device 9.
[0044] In order to make better use of low-quality exhaust steam, such as Figure 2 As shown, the return water from the hot network first enters the first heat exchange device 4. The first heat exchange device 4 extracts low-pressure exhaust steam from the low-pressure cylinder 200 of the high-back-pressure coal-fired generator set for heat exchange with the return water from the hot network to preliminarily heat the return water. The preliminarily heated return water from the hot network can first enter the second heating device 9 before entering the first heating device 5. The intermediate-pressure exhaust steam is transported to the upgrading device 10 through the intermediate-pressure cylinder 100 of the high-back-pressure coal-fired generator set to drive the upgrading device 10. The upgrading device 10 increases the temperature and pressure of the low-pressure exhaust steam from the low-pressure cylinder 200 of the high-back-pressure coal-fired generator set entering the second heating device 9. In this way, after the return water from the hot network discharged from the first heat exchange device 4 enters the second heating device 9, the second heating device 9 uses the upgraded low-pressure exhaust steam to exchange heat with the return water from the hot network, thereby heating the return water from the first heat exchange device 4. The return water from the second heating device 9 is then sent to the first heating device 5 for heat exchange with the intermediate-pressure exhaust steam from the intermediate-pressure cylinder 300 of the coal-fired generator set after cylinder cutting and reconstruction. The first heating device 5 can also be fed with reheated steam from high-back-pressure coal-fired generator sets and reheated steam from cylinder-cutting coal-fired generator sets via the supplemental steam line 3. The reheated steam enters the first heating device 5 and exchanges heat with the return water from the second heating device 9, thereby increasing the temperature of the return water. A water supply bypass pipe 8 is provided to connect the heating water outlet of the first heating device 5 and the water outlet of the second heating device 9. In this way, when the return water from the heating network heated by the second heating device 9 meets the preset temperature of the heat supply water, the return water from the second heating device 9 can flow through the water supply bypass pipe 8 and enter the heat supply system or enter the first storage unit of the heat storage device 6 for storage, preventing the return water from the second heating device 9 from flowing through the first heating device 5 again. A water supply bypass control valve 81 is provided on the water supply bypass pipe 8 to control the flow of the return water from the second heating device 9 through the water supply bypass channel, that is, to control the flow state of the return water from the second heating device 9 in the water supply bypass pipe 8.
[0045] In yet another embodiment, Figure 3 As shown, it also includes: a second heat exchange device 11, which is connected to the exhaust port of the low-pressure cylinder 200 of at least one group of high back-pressure coal-fired power generation units, and is used to use the low-pressure steam discharged from the low-pressure cylinder 200 of the high back-pressure coal-fired power generation units connected thereto to heat the heat network return water discharged from the first heat exchange device 4.
[0046] The heat network return water of the heat network system can be preliminarily heated by using the low-pressure cylinder 200 low-pressure exhaust steam of one or more groups of high-backpressure coal-fired generator sets to exchange heat with the heat network return water flowing through the first heat exchange device 4, the heat network return water discharged from the first heat exchange device 4 enters the second heat exchange device 11, the second heat exchange device 11 extracts the low-pressure cylinder 200 low-pressure exhaust steam of at least one group of high-backpressure coal-fired generator sets to heat the heat network return water discharged from the first heat exchange device 4, the second heat exchange device 11 can also extract the low-pressure cylinder 200 low-pressure exhaust steam of multiple groups of high-backpressure coal-fired generator sets to heat the heat network return water discharged from the first heat exchange device 4, when the temperature of the heat network return water discharged from the second heat exchange device 11 is lower than the preset temperature of the heat network supply water, the heat network return water discharged from the second heat exchange device 11 enters the first heating device 5, the first heating device 5 heats the heat network return water discharged from the second heat exchange device 11 by extracting the medium-pressure cylinder 300 medium-pressure exhaust steam of the cylinder-cut coal-fired generator set, and the heat network return water is gradually heated by the first heat exchange device 4, the second heat exchange device 11 and the first heating device 5 to become the heat network supply water for heating. The first heating device 5 can also send the reheat steam flowing in the high-backpressure coal-fired generator set and the cylinder-cut coal-fired generator set to the first heating device 5 through the steam supplement pipeline 3 to exchange heat with the heat network return water discharged from the second heat exchange device 11, so that the temperature of the heat network return water is increased. The heating outlet of the first heating device 5 and the outlet of the second heat exchange device 11 are connected by the supply water bypass pipeline 8, when the temperature of the heat network return water discharged from the second heat exchange device 11 meets the preset temperature of the heat network supply water, the heat network return water discharged from the second heat exchange device 11 can flow through the supply water bypass pipeline 8 and then enter the heat network system for heating or enter the first storage part of the heat storage device 6 for storage, so as to avoid flowing through the first heating device 5 again, and the supply water bypass control valve 81 is arranged on the supply water bypass pipeline 8 to control the opening and closing of the supply water bypass pipeline 8, that is, to control the flow state of the heat network return water discharged from the second heat exchange device 11 in the supply water bypass pipeline 8.
[0047] As shown in Figures 1-3 when the actual heat network supply water temperature is higher than the preset heat network supply water temperature, part of the heat network supply water can be stored by the heat storage device 6.
[0048] The utility model discloses a kind of heat and power cogeneration energy cascade heat supply systems, the heat and power cogeneration energy cascade heat supply module of any one described above.
[0049] Another aspect of the present application provides a kind of heat and power cogeneration energy cascade heat supply module selection method, for selecting the heat and power cogeneration energy cascade heat supply module described above any one to heat the heat network return water of heat network system, the selection method of the heat and power cogeneration energy cascade heat supply module includes:
[0050] Acquire the operation state of high back pressure coal-fired generating units and cylinder cut-off reformed coal-fired generating units;
[0051] According to the operation state of high back pressure coal-fired generating units and cylinder cut-off reformed coal-fired generating units, select a combined heat and power energy cascade heat supply module to increase the temperature of the heat network return water of the heat network system;
[0052] If the high back pressure coal-fired generating units and the cylinder cut-off reformed coal-fired generating units are in peak shaving operation, compare the preset heat network supply water temperature of the heat network system with the actual heat network supply water temperature, and according to the comparison result, select the steam supplement pipeline and / or the heat storage device and / or the second heating device or the second heat exchange device to work to increase the temperature of the heat network return water to become the heat network supply water;
[0053] If the coal-fired generating units are in conventional heat supply operation, according to the actual heating period, select the first heat exchange device and / or the first heating device and / or the second heating device or the second heat exchange device to work to increase the temperature of the heat network return water to become the heat network supply water.
[0054] Specifically, the comparison of the preset heat network supply water temperature of the heat network system with the actual heat network supply water temperature, and according to the comparison result, selection of the steam supplement pipeline and / or the heat storage device and / or the second heating device or the second heat exchange device to work to increase the temperature of the heat network return water, comprises:
[0055] When the actual heat network supply water temperature is greater than or equal to the preset heat network supply water temperature, select the first heat exchange device and / or the second heating device or the second heat exchange device to work to increase the temperature of the heat network return water to form the heat network supply water, and store the excess heat network supply water through the heat storage device;
[0056] When the actual heat network supply water temperature is less than the preset heat network supply water temperature, select the steam supplement pipeline or the heat storage device and the first heat exchange device and the first heating device to work to increase the temperature of the heat network return water.
[0057] Specifically, the selection of the first heat exchange device and / or the first heating device and / or the second heating device or the second heat exchange device to work to increase the temperature of the heat network return water according to the actual required heating period, comprises:
[0058] When the heating period is in the cold period, select the first heat exchange device and the first heating device to work to increase the temperature of the heat network return water;
[0059] When the heating period is in the early cold period or the late cold period, select the first heat exchange device or the second heating device or the second heat exchange device to work to increase the temperature of the heat network return water.
[0060] The selection method further comprises:
[0061] The number of high back pressure coal-fired generating units and cylinder cut-off retrofit coal-fired generating units participating in heating the return water of the heat supply network is selected according to the temperature and flow of the return water of the heat supply network of the heat supply network system.
[0062] In order to reasonably select the heat and power cogeneration energy cascade heating module to heat the return water of the heat supply network, after obtaining the operation states of multiple high back pressure coal-fired generating units and cylinder cut-off retrofit coal-fired generating units, the heat and power cogeneration energy cascade heating module is selected, if the high back pressure coal-fired generating units and the cylinder cut-off retrofit coal-fired generating units are operated for peak shaving, when flexible peak shaving is needed, the heat supply network water supply temperature is monitored in real time, the actual heat supply network water supply temperature is compared with the preset heat supply network water supply temperature, when the actual heat supply network water supply temperature is greater than or equal to the preset heat supply network water supply temperature, the heat storage device is selected to be put into work to store the excess heat supply network water through the heat storage device; when the actual heat supply network water supply temperature is less than the preset heat supply network water supply temperature, the heat storage device is selected to be put into work, that is, the heat supply network water stored in the heat storage device is delivered to the heat supply network system for heating; when the heat storage device is put into work, and the actual heat supply network water supply temperature is still less than the preset heat supply network water supply temperature, the steam supplement pipeline is put into work to participate in the work of heating the return water of the heat supply network, the reheat steam of at least one high back pressure coal-fired generating unit and at least one cylinder cut-off retrofit coal-fired generating unit is extracted and sent to the first heating device for heating the return water of the heat supply network.
[0063] If the high back pressure coal-fired generating units and the cylinder cut-off retrofit coal-fired generating units are operated for regular heating, the steam supplement pipeline does not need to be put into work, in the cold period, when the temperature of the return water of the heat supply network heated by the first heat exchange device is lower than the required water supply temperature, the first heating device and / or the second heating device or the second heat exchange device is put into work to heat the return water of the heat supply network through the first heat exchange device and the first heating device and / or the second heating device or the second heat exchange device, in this way, the return water of the heat supply network flows through the first heat exchange device and the first heating device in turn, the return water of the heat supply network flows through the first heat exchange device, the second heating device and the first heating device in turn, and the return water of the heat supply network flows through the first heat exchange device, the second heat exchange device and the first heating device in turn, the return water of the heat supply network is preliminarily heated by the first heat exchange device, then the return water of the heat supply network is heated again by the second heat exchange device or the second heating device, and finally the return water of the heat supply network is heated again by the first heating device to become the heat supply network water supply, in the cold period, the first heating device and the first heating device and / or the second heating device or the second heat exchange device are put into work to heat the return water of the heat supply network, which can more quickly heat the return water of the heat supply network to the required temperature, in the early cold period or the late cold period, when the temperature of the return water of the heat supply network heated by the first heat exchange device is higher than or close to the required water supply temperature, the first heat exchange device can be selected to be put into work, the return water of the heat supply network flows through the first heat exchange device to heat the return water of the heat supply network by the low pressure steam, at this time, the first heating device, the second heating device and the second heat exchange device do not participate in heating the return water of the heat supply network.
[0064] In practical applications, the number of high back pressure coal-fired generating units and cylinder cut-off retrofit coal-fired generating units participating in heating of the heat network return water is selected according to the flow and temperature of the heat network return water, if the flow of the heat network return water is large and the water temperature is low, the low-pressure steam of one high back pressure coal-fired generating unit and the medium-pressure steam of one cylinder cut-off retrofit coal-fired generating unit cannot heat the heat network return water to the preset heat network supply water temperature, the number of high back pressure coal-fired generating units and cylinder cut-off retrofit coal-fired generating units participating in heating of the heat network return water can be increased, so as to meet the heat supply requirement of the heat network system.
[0065] The cogeneration energy cascade heat supply module provided by the utility model, first heat exchange device and at least one group of high back pressure coal-fired generating unit's low-pressure cylinder's exhaust port are connected, the low-pressure steam exhausted by the low-pressure cylinder of the high back pressure coal-fired generating unit and the heat network return water from the heat network system are used to heat the heat network return water to preliminarily heat the heat network return water, the preliminarily heated heat network return water is sent into the first heating device, the first heating device is connected with the exhaust port of at least one group of cylinder cut-off retrofit coal-fired generating unit's medium-pressure cylinder, the medium-pressure steam exhausted by the medium-pressure cylinder of the cylinder cut-off retrofit coal-fired generating unit is used to heat the heat network return water from the first heat exchange device for the second time, the heat network return water after the second heating is increased in temperature and becomes the heat network supply water, meanwhile, the reheat steam of at least one group of high back pressure coal-fired generating unit and at least one group of cylinder cut-off retrofit coal-fired generating unit can be supplemented to the first heating device through the steam supplement pipeline, the heat network return water is heated by the reheat steam to form the heat network supply water, the heat network supply water can be used for heat supply, the heat network supply water can also be sent into the first storage part of the heat storage device for storage, the heat network supply water stored in the first storage part can also be supplied to the heat network system for heat supply, the second storage part can send the stored heat network supply water after temperature reduction to the first heat exchange device as the heat network return water. The cogeneration energy cascade heat supply module and system provided by the utility model use the low-pressure steam of the high back pressure coal-fired generating unit and the medium-pressure steam of the cylinder cut-off retrofit coal-fired generating unit and the reheat steam of the high back pressure coal-fired generating unit and the cylinder cut-off retrofit coal-fired generating unit to cascade heat the heat network return water, not only can the low-grade exhaust steam of the reheat steam of the high back pressure coal-fired generating unit and the cylinder cut-off retrofit coal-fired generating unit be used, but also can the exhaust steam waste heat be used as much as possible in the reheat steam peak regulation state of the high back pressure coal-fired generating unit and the cylinder cut-off retrofit coal-fired generating unit, the heat supply economy is improved, and the problem that the heat supply coal consumption increases when the coal-fired generating unit is in peak regulation operation due to the flexibility of realizing the linkage heat supply of multiple coal-fired generating units in the prior art is solved.
[0066] The above describes the optional implementation manners of the utility model embodiments in detail in combination with the drawings, but the utility model embodiments are not limited to the specific details in the above implementation manners, and various simple modifications can be made to the technical solutions of the utility model embodiments within the technical concept scope of the utility model embodiments, and these simple modifications all belong to the protection scope of the utility model embodiments.
[0067] It should be further noted that various specific technical features described in the above specific embodiments can be combined in any suitable manner, without contradiction. In order to avoid unnecessary repetition, various possible combinations of the embodiments of the present application are not described again.
[0068] In addition, various different embodiments of the present application can be combined in any manner, as long as they do not contradict the spirit of the present application, and should be considered as disclosed by the present application.
Claims
1. A cogeneration energy cascade heating module, connected to a heat network system and to multiple groups of high back pressure coal-fired generator sets and multiple groups of cylinder-cutting coal-fired generator sets, the high back pressure coal-fired generator sets and the cylinder-cutting coal-fired generator sets being able to supply reheat steam to the cogeneration energy cascade heating module, characterized in that: The cogeneration energy cascade heating module includes: A first heat exchange device (4) connected to the water outlet of the heat network system is used to connect to the exhaust port of the low-pressure cylinder (200) of at least one group of high-back-pressure coal-fired power generation units; low-pressure exhaust steam discharged from the low-pressure cylinder (200) of the high-back-pressure coal-fired power generation units is used to preliminarily heat the heat network return water from the heat network system; The first heating device (5) is connected to the heat exchange outlet of the first heat exchange device (4), and is used to be connected to the exhaust port of the intermediate pressure cylinder (300) of at least one group of cylinder-cutting and reformed coal-fired generator sets, and to use the intermediate exhaust steam discharged from the intermediate pressure cylinder (300) of the cylinder-cutting and reformed coal-fired generator sets to secondary heat the heat network return water discharged from the first heat exchange device (4) to become the heat network supply water, and the heat network supply water is discharged from the heating outlet of the first heating device (5); The supplementary steam pipeline (3) is used to supply reheated steam from at least one group of high back pressure coal-fired power generation units and at least one group of cylinder-cutting modified coal-fired power generation units to the first heating device (5) via the supplementary steam pipeline (3); the first heating device (5) uses the reheated steam to heat the heat network return water discharged from the first heat exchange device (4) to produce heat network supply water; The heat storage device (6) comprises a first storage portion and a second storage portion which are connected to each other, wherein the first storage portion is connected to the heating water outlet of the first heating device (5) and is used to recover and store the heat network water discharged from the first heating device (5); and the second storage portion is connected to the heat exchange water inlet of the first heat exchange device (4) and is used to store the cooled heat network water from the first storage portion and transport the cooled heat network water as heat network return water to the first heat exchange device (4).
2. The combined heat and power energy cascade heating module according to claim 1, characterized in that: The supplementary steam pipeline (3) includes a supplementary steam main line (31) and a plurality of supplementary steam branch lines (32); The main steam supply line (31) has a steam outlet and a plurality of steam inlets. The steam outlet of the main steam supply line (31) is connected to the steam inlet of the first heating device (5). At least one group of high back pressure coal-fired power generation units is connected to one steam supply branch line (32). At least one group of cylinder-cutting coal-fired power generation units is connected to another steam supply branch line (32). The reheated steam from the high back pressure coal-fired power generation units and the reheated steam from the cylinder-cutting coal-fired power generation units enter the main steam supply line (31) through the corresponding steam supply branch lines (32), and then enter the first heating device (5) through the main steam supply line (31).
3. The combined heat and power energy cascade heating module according to claim 2, characterized in that: Also includes: A water supply bypass pipe (8) is connected from the heat exchange outlet of the first heat exchange device (4) to the heating outlet of the first heating device (5), and is connected in parallel with the heat network inlet and outlet channels of the first heating device (5) to form a water supply bypass pipe (8).
4. The combined heat and power energy cascade heating module according to claim 3, characterized in that: A water supply bypass control valve (81) is provided on the water supply bypass pipe (8) for controlling the on-off of the water supply bypass channel.
5. The combined heat and power energy cascade heating module according to claim 3, characterized in that: An inlet control valve (51) is provided on the connecting pipe between the heat exchange outlet of the first heat exchange device (4) and the heating water inlet of the first heating device (5) for controlling the flow state of the heat network return water discharged from the first heat exchange device (4) in the connecting pipe between the heat exchange outlet of the first heat exchange device (4) and the heating water inlet of the first heating device (5).
6. The combined heat and power energy cascade heating module according to claim 5, characterized in that: Also includes: The second heating device (9) is arranged between the heat exchange outlet of the first heat exchange device (4) and the heating water inlet of the first heating device (5). The second heating device (9) uses the exhaust steam of the intermediate pressure cylinder (100) and the exhaust steam of the low pressure cylinder (200) of at least one group of high back pressure coal-fired power generation units to heat the heat network return water discharged from the heat exchange outlet of the first heat exchange device (4). The heat network return water auxiliary-heated by the second heating device (9) is sent to the first heating device (5).
7. The combined heat and power cascade heating module according to claim 6, characterized in that: Also includes: The steam quality improvement device (10) is connected to the steam inlet of the second heating device (9) and the steam exhaust port of the intermediate pressure cylinder (100) and the steam exhaust port of the low pressure cylinder (200) of at least one group of high back pressure coal-fired power generation units through pipelines. The steam quality improvement device (10) is driven by the intermediate exhaust steam discharged from the intermediate pressure cylinder (100) of the high back pressure coal-fired power generation unit to increase the temperature and pressure of the low exhaust steam entering the second heating device (9).
8. The combined heat and power cascade heating module according to claim 5, characterized in that: Also includes: The second heat exchange device (11) is connected to the exhaust port of the low-pressure cylinder (200) of at least one group of high-back-pressure coal-fired power generation units, and is used to heat the heat network return water discharged from the first heat exchange device (4) using the low-pressure exhaust steam discharged from the low-pressure cylinder (200) of the high-back-pressure coal-fired power generation units connected thereto.
9. The combined heat and power energy cascade heating module according to claim 5, characterized in that: The heat storage device (6) is a heat storage tank.
10. A combined heat and power cascade heating system, characterized in that: The cogeneration energy cascade heating system comprises the cogeneration energy cascade heating module according to any one of claims 1 to 9.