High-back-pressure heat supply adjusting system and method

Abstract

The invention provides a high-back-pressure heat supply adjusting system and method, and relates to the technical field of heat supply control, and the system comprises a high-back-pressure heat supply unit, a non-high-back-pressure heat supply unit, a first condenser, a second condenser, a heat supply network heater and at least one heat supply network return water cooler; a steam exhaust port of the high-back-pressure heat supply unit is connected with a steam inlet of the first condenser, a circulating water outlet of the first condenser is connected with a circulating water inlet of the heat supply network heater, and a circulating water outlet of the heat supply network heater is connected with a circulating water inlet of the user side. The steam inlet of the heat supply network heater is further connected with a steam exhaust port of the non-high-back-pressure heat supply unit. A steam exhaust port of the non-high back pressure heat supply unit is further connected with a steam inlet of a second condenser, a circulating water inlet of the second condenser is connected with a circulating water outlet of the cooling tower on the side of the non-high back pressure heat supply unit, and a circulating water outlet of the second condenser is connected with a circulating water inlet of the cooling tower on the side of the non-high back pressure heat supply unit; a circulating water outlet of the user side is connected with at least one heat supply network return water cooler, and the at least one heat supply network return water cooler is used for conveying the cooled circulating water to a circulating water inlet of the first condenser after the circulating water from the user side is subjected to heat exchange and cooling with a specified heat exchange target. The problem that the back pressure of the unit exceeds the limit can be effectively solved.

Description

Technical Field

[0001] The present application relates to the technical field of heating control, and in particular to a high back pressure heating regulation system and a high back pressure heating regulation method. Background Art

[0002] A thermal power plant is a thermal power plant that uses a combined heat and power unit to generate both electricity and heat. The principle is to use the steam from the steam turbine to supply steam and heat to users while generating electricity. It has now become the main way of heating cities, industrial parks and industrial steam. At present, conventional heating methods for thermal power plants include mid-exhaust steam extraction heating, steam turbine high back pressure heating and other heating methods.

[0003] Among them, the middle row steam extraction heating is to extract steam from the connecting pipe between the middle row and the low-pressure cylinder of the thermal power unit, and then introduce it into the first heating station to heat the circulating water of the heat network for heating. However, the temperature of the middle row steam is relatively high, and it needs to be cooled to meet the heating demand, which inevitably causes energy loss. When the unit is deeply peak-shaving, the middle row steam extraction method needs to be combined with technologies such as low-pressure cylinder cutting and steam supply to ensure the stability of steam parameters and extraction volume. Steam turbine high back pressure heating uses the exhaust steam of the steam turbine to heat the circulating water of the heat network for heating. This heating method uses the method of increasing the exhaust pressure, that is, using high back pressure for heating. Large steam turbine units use high back pressure waste heat for heating, which can reduce the loss of available energy caused by traditional steam extraction heating, and the recovery of exhaust waste heat can also expand the heating capacity of the unit.

[0004] However, in the current steam turbine high back-pressure heating system, if the external heat load demand is lower than the maximum heating load condition of the high back-pressure heating unit, the heat at the cold end of the high back-pressure heating unit cannot be completely taken away, thereby causing the back pressure to increase. When the upper limit of the unit's back pressure is reached, the unit load needs to be reduced to ensure that the back pressure is lower than the upper limit, resulting in restrictions on the electrical load regulation of the high back-pressure heating unit, especially in the initial and final stages of heating, when the external heat load demand is very low, and the electrical load regulation of the high back-pressure heating unit is severely restricted. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a high back pressure heat supply regulation system and a high back pressure heat supply regulation method to solve the above-mentioned problems.

[0006] In order to achieve the above-mentioned object, the first aspect of the present application provides a high back pressure heating regulation system, comprising:

[0007] A high back pressure heating unit, a non-high back pressure heating unit, a first condenser, a second condenser, a heating network heater and at least one heating network return water cooler;

[0008] The steam exhaust port of the high back pressure heating unit is connected to the steam inlet of the first condenser, the circulating water outlet of the first condenser is connected to the circulating water inlet of the heating network heater, the circulating water outlet of the heating network heater is connected to the circulating water inlet of the user end, and the steam inlet of the heating network heater is also connected to the steam exhaust port of the non-high back pressure heating unit;

[0009] The steam exhaust port of the non-high back pressure heating unit is also connected to the steam inlet of the second condenser, the circulating water inlet of the second condenser is connected to the circulating water outlet of the cooling tower on the non-high back pressure heating unit side, and the circulating water outlet of the second condenser is connected to the circulating water inlet of the cooling tower on the non-high back pressure heating unit side;

[0010] The circulating water outlet at the user end is connected to the at least one heat network return water cooler, and the at least one heat network return water cooler is used to cool the circulating water from the user end by heat exchange with a designated heat exchange target, and then transport the cooled circulating water to the circulating water inlet of the first condenser.

[0011] Optionally, the at least one heat network return water cooler comprises:

[0012] The first heat network return water cooler;

[0013] The circulating water outlet of the user end is connected to the circulating water inlet of the first heat network return water cooler, and the circulating water outlet of the first heat network return water cooler is connected to the circulating water inlet of the first condenser;

[0014] The specified heat exchange target includes:

[0015] Secondary air of boiler;

[0016] The first heat network return water cooler is used to heat the secondary air of the boiler.

[0017] Optionally, the at least one heat network return water cooler comprises:

[0018] Second heat network return water cooler;

[0019] The circulating water outlet of the user end is connected to the circulating water inlet of the second heat network return water cooler, and the circulating water outlet of the second heat network return water cooler is connected to the circulating water inlet of the first condenser;

[0020] The specified heat exchange target includes:

[0021] Condenser water replenishment;

[0022] The second heat network return water cooler is used to heat the condenser feed water.

[0023] Optionally, the at least one heat network return water cooler comprises:

[0024] The third heat network return water cooler;

[0025] The circulating water outlet of the user end is connected to the circulating water inlet of the third heat network return water cooler, and the circulating water outlet of the third heat network return water cooler is connected to the circulating water inlet of the first condenser;

[0026] The specified heat exchange target includes:

[0027] Cooling tower on the non-high back pressure heating unit side;

[0028] The circulating water inlet of the second condenser is connected to the circulating water outlet of the cooling tower on the non-high back pressure heating unit side, and is also connected to the circulating water inlet of the third heat network return water cooler. The circulating water outlet of the third condenser is connected to the circulating water inlet of the cooling tower on the non-high back pressure heating unit side, and is also connected to the circulating water outlet of the third heat network return water cooler.

[0029] Optionally, the system further comprises:

[0030] A first circulating water pump and a second circulating water pump;

[0031] The circulating water outlet of the first condenser is connected to the circulating water inlet of the heating network heater through the first circulating water pump;

[0032] The circulating water inlet of the second condenser is connected to the circulating water outlet of the cooling tower on the non-high back pressure heating unit side through the second circulating water pump.

[0033] Optionally, the system further comprises:

[0034] A first temperature sensor, a first solenoid valve, a second solenoid valve and a third solenoid valve;

[0035] The first temperature sensor is disposed in the circulating water outlet of the user end, and is used to collect the circulating water temperature at the circulating water outlet of the user end;

[0036] The first solenoid valve is arranged between the circulating water outlet of the user end and the circulating water inlet of the first heat network return water cooler, and is used to adjust the circulating water flow entering the first heat network return water cooler;

[0037] The second solenoid valve is arranged between the circulating water outlet of the user end and the circulating water inlet of the second heat network return water cooler, and is used to adjust the circulating water flow entering the second heat network return water cooler;

[0038] The third solenoid valve is arranged between the circulating water outlet of the user end and the circulating water inlet of the third heat network return water cooler, and is used to adjust the circulating water flow entering the third heat network return water cooler.

[0039] A second aspect of the present application provides a high back pressure heat supply regulation method, using the above-mentioned high back pressure heat supply regulation system, the method comprising:

[0040] Determine the target temperature of the circulating water entering the first condenser, and obtain the actual temperature of the circulating water collected by the first temperature sensor;

[0041] Calculating the temperature difference between the actual temperature and the target temperature of the circulating water entering the first condenser, and determining at least one of the first heating network return water cooler, the second heating network return water cooler, and the third heating network return water cooler as the target heating network return water cooler based on the temperature difference;

[0042] Determine the target temperature of the circulating water outlet of the corresponding target heat network return water cooler based on the target temperature of the circulating water entering the first condenser;

[0043] A flow prediction model corresponding to a corresponding target heating network return water cooler is called, and the target temperature of the circulating water outlet of the corresponding target heating network return water cooler and the actual temperature are taken as inputs. The corresponding flow prediction model outputs the predicted flow of circulating water entering the corresponding target heating network return water cooler, and the opening of the solenoid valve arranged between the circulating water outlet at the user end and the circulating water inlet of the corresponding heating network return water cooler is controlled according to the obtained predicted flow, so that the circulating water flow entering the corresponding heating network return water cooler matches the obtained predicted flow.

[0044] Optionally, determining at least one of the first heating network return water cooler, the second heating network return water cooler and the third heating network return water cooler as a target heating network return water cooler based on the temperature difference comprises:

[0045] If the temperature difference is lower than a first temperature difference threshold, determining the first heating network return water cooler or the second heating network return water cooler as a target heating network return water cooler;

[0046] If the temperature difference is not lower than the first temperature difference threshold, and the temperature difference is lower than the second temperature difference threshold, determining the first heating network return water cooler and the second heating network return water cooler as target heating network return water coolers;

[0047] If the temperature difference is not lower than the second temperature difference threshold, and the temperature difference is lower than the third temperature difference threshold, determining the first heating network return water cooler or the second heating network return water cooler as the target heating network return water cooler, and determining the third heating network return water cooler as the target heating network return water cooler;

[0048] If the temperature difference is not lower than the third temperature difference threshold, the first heating network return water cooler, the second heating network return water cooler and the third heating network return water cooler are determined as target heating network return water coolers.

[0049] Optionally, determining a target temperature of a circulating water outlet of a corresponding target heat network return water cooler based on a target temperature of the circulating water entering the first condenser includes:

[0050] In the case where there are one or more return water coolers in the corresponding heat network, the target temperature of the circulating water entering the first condenser is determined to be the target temperature of the circulating water outlet of the corresponding heat network return water cooler; or

[0051] When there are multiple return water coolers corresponding to the heat network, the target temperature of the circulating water outlet of the return water cooler corresponding to the heat network is determined according to a preset ratio at the target temperature of the circulating water entering the first condenser.

[0052] Optionally, the steps of constructing the traffic prediction model include:

[0053] Obtain the historical target temperature of the circulating water outlet of the corresponding target heat network return water cooler, the historical actual temperature corresponding to each historical target temperature, and the historical actual flow rate of the circulating water entering the corresponding target heat network return water cooler corresponding to each historical target temperature and each historical actual temperature;

[0054] The historical target temperature of the circulating water outlet of the corresponding target heat network return water cooler and the corresponding historical actual temperature are used as the input of the preset neural network, and the predicted flow rate of the circulating water entering the corresponding target heat network return water cooler is output by the preset neural network. Based on the obtained predicted flow rate and the corresponding historical actual flow rate of the circulating water entering the corresponding target heat network return water cooler, the network parameters of the preset neural network are adjusted until the preset neural network meets the convergence conditions, and the corresponding flow prediction model of the target heat network return water cooler is obtained.

[0055] The embodiments provided in this application have the following beneficial effects:

[0056] The present application constructs multiple heat network return water coolers connected to the circulating water outlet at the user end, which can exchange heat between the circulating water from the user end and the specified heat exchange target, so as to reuse the heat of the circulating water from the user end, and at the same time further cool the circulating water from the user end before circulating into the condenser on the high back pressure heating unit side, thereby effectively solving the problem of excessive back pressure of the unit.

[0057] Other features and advantages of the embodiments or implementations of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0059] Figure 1 The system structure diagram of the existing high back pressure heating system according to the embodiment of the present application is schematically shown;

[0060] Figure 2 A schematic diagram of the system structure of a high back pressure heating regulation system according to an embodiment of the present application is shown;

[0061] Figure 3 A method flow chart of a high back pressure heating regulation method according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0062] The specific implementation of the embodiment of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present application, and is not used to limit the embodiment of the present application.

[0063] Steam turbine high back pressure heating uses the exhaust steam of the steam turbine to heat the circulating water of the heat network for heating. This heating method uses the method of increasing the exhaust steam pressure, that is, using high back pressure to provide heat. Existing high back pressure heating systems such as Figure 1 As shown, the high back-pressure heating unit includes a high-pressure cylinder 1, a medium-pressure cylinder 2 and a low-pressure cylinder 3 connected in sequence. The steam generated by the boiler converts thermal energy into mechanical energy through the high-pressure cylinder 1, the medium-pressure cylinder 2 and the low-pressure cylinder 3, thereby driving the generator 8 to generate electricity. The extraction steam from the low-pressure cylinder 3 enters the condenser 4 to exchange heat with the circulating water, and then is reheated by the heat network heater 7 and transported to the heat user 6 for heating through the heat network circulating water pump 5. However, when the external heat load demand of the existing high back-pressure heating system is lower than the maximum heating load condition of the high back-pressure heating unit, the heat at the cold end of the high back-pressure heating unit cannot be completely taken away, thereby causing the back pressure to increase.

[0064] In order to solve the above problems, Figure 2 As shown, the first aspect of the present application provides a high back pressure heating regulation system, comprising:

[0065] A high back pressure heating unit, a non-high back pressure heating unit, a first condenser 13, a second condenser 24, a heating network heater 15 and at least one heating network return water cooler;

[0066] The exhaust port of the high back pressure heating unit is connected to the steam inlet of the first condenser 13, the circulating water outlet of the first condenser 13 is connected to the circulating water inlet of the heating network heater 15, the circulating water outlet of the heating network heater 15 is connected to the circulating water inlet of the user end 19, and the steam inlet of the heating network heater 15 is also connected to the exhaust port of the non-high back pressure heating unit; it can be understood that the system of the present application also includes a first circulating water pump 14; the circulating water outlet of the first condenser 13 is connected to the circulating water inlet of the heating network heater 15 through the first circulating water pump 14;

[0067] The steam exhaust port of the non-high back pressure heating unit is also connected to the steam inlet of the second condenser 24, the circulating water inlet of the second condenser 24 is connected to the circulating water outlet of the cooling tower 25 on the non-high back pressure heating unit side, and the circulating water outlet of the second condenser 24 is connected to the circulating water inlet of the cooling tower 25 on the non-high back pressure heating unit side;

[0068] The circulating water outlet of the user end 19 is connected to at least one heat network return water cooler, which is used to cool the circulating water from the user end 19 by heat exchange with a designated heat exchange target, and then transport the cooled circulating water to the circulating water inlet of the first condenser 13.

[0069] In this way, the present application constructs multiple heat network return water coolers connected to the circulating water outlet at the user end, so as to exchange heat between the circulating water from the user end and the designated heat exchange target, so as to reuse the heat of the circulating water from the user end, and at the same time further cool the circulating water from the user end before circulating into the condenser on the high back pressure heating unit side, thereby effectively solving the problem of excessive back pressure of the unit.

[0070] Specifically, in the regulation system of the present application, the high back pressure heating unit includes a high pressure cylinder 9, a medium pressure cylinder 10 and a low pressure cylinder 11 connected in sequence. The steam generated by the boiler converts thermal energy into mechanical energy through the high pressure cylinder 9, the medium pressure cylinder 10 and the low pressure cylinder 11, thereby driving the generator 12 to generate electricity. The extraction steam from the low-pressure cylinder 11 of the high back-pressure heating unit enters the first condenser 13, which is used to perform heat exchange heating on the circulating water. Under the action of the first circulating water pump 14, the circulating water enters the heat network heater 15 for heat exchange heating again and is then transported to the user end 19 of the heat user for heating. After that, it is output to the heat network return water cooler through the circulating water outlet of the user end 19. There may be multiple heat network return water coolers. The heat network return water cooler performs heat exchange between the circulating water from the user end 19 and the designated heat exchange target to cool the circulating water, and then transports the cooled circulating water to the circulating water inlet of the first condenser 13, thereby effectively avoiding the problem of increased back pressure caused by the inability to take away all the heat from the cold end of the high back-pressure heating unit.

[0071] It can be understood that in the present application, the non-high back pressure heating unit includes a high pressure cylinder 20, a medium pressure cylinder 21 and a low pressure cylinder 22 connected in sequence, and the steam generated by the boiler converts the thermal energy into mechanical energy through the high pressure cylinder 20, the medium pressure cylinder 21 and the low pressure cylinder 22, thereby driving the generator 23 to generate electricity. Among them, the steam inlet of the heat network heater 15 is connected to the exhaust port of the non-high back pressure heating unit, and the circulating water is heated by the extraction steam from the non-high back pressure heating unit.

[0072] In a specific example of the present application, at least one heat network return water cooler includes: a first heat network return water cooler 16; the circulating water outlet of the user end 19 is connected to the circulating water inlet of the first heat network return water cooler 16, and the circulating water outlet of the first heat network return water cooler 16 is connected to the circulating water inlet of the first condenser 13; the designated heat exchange target includes: the secondary air of the boiler; the first heat network return water cooler 16 is used to heat the secondary air of the boiler.

[0073] It is understandable that the combustion process of the boiler requires the use of air. Primary air and secondary air refer to two ways of introducing air into the combustion chamber of the boiler. Among them, primary air refers to the air introduced from the outside of the boiler directly into the combustion chamber, while secondary air is to divide the air into two parts, one part directly enters the combustion chamber through the air inlet duct of the burner, and the other part enters the combustion chamber through the secondary air duct on the rear wall of the boiler. The secondary air can further increase the temperature and speed in the combustion chamber and promote the combustion. In the present application, the first heat network return water cooler 16 can be used as an auxiliary heater for the secondary air of the boiler. For example, it is arranged in the secondary air duct, and the secondary air is auxiliary heated by the waste heat of the circulating water from the user end 19 to increase the temperature of the secondary air, thereby improving the combustion efficiency of the air.

[0074] In another specific example of the present application, at least one heat network return water cooler may also include: a second heat network return water cooler 17; the circulating water outlet of the user end 19 is connected to the circulating water inlet of the second heat network return water cooler 17, and the circulating water outlet of the second heat network return water cooler 17 is connected to the circulating water inlet of the first condenser 13; the designated heat exchange target includes: condenser feed water; the second heat network return water cooler 17 is used to heat the condenser feed water.

[0075] It can be understood that condensate make-up water refers to the make-up water used to make up for the reduction of water in the condensate system due to evaporation loss, emission loss, leakage and other factors in the thermal cycle system of the power plant. It is mainly used to maintain the water balance of the condensate system to ensure that there is enough water circulation to meet the needs of steam generation and condensation. Condensate is saturated high-temperature softened water, which is usually recycled as boiler feed water. The second heat network return water cooler 17 of the present application can be used to heat the condensate make-up water. For example, the second heat network return water cooler 17 can be arranged in the condensate make-up water pipeline, and the waste heat of the circulating water from the user end 19 is used to heat the condensate make-up water, thereby increasing the temperature of the condensate make-up water, and can make full use of the thermal energy of the circulating water from the user end 19. At the same time, it can cool the circulating water from the user end 19, thereby reducing the temperature of the circulating water transported to the first condenser 13. Among them, the condensate make-up water can be the recycled water after sewage treatment.

[0076] In another specific example of the present application, at least one heat network return water cooler may also include: a third heat network return water cooler 18; the circulating water outlet of the user end 19 is connected to the circulating water inlet of the third heat network return water cooler 18, and the circulating water outlet of the third heat network return water cooler 18 is connected to the circulating water inlet of the first condenser 13; the designated heat exchange target includes: a cooling tower 25 on the non-high back pressure heating unit side; wherein, the circulating water inlet of the second condenser 24 is connected to the circulating water outlet of the cooling tower 25 on the non-high back pressure heating unit side and then connected to the circulating water inlet of the third heat network return water cooler 18, and the circulating water outlet of the third condenser is connected to the circulating water inlet of the cooling tower 25 on the non-high back pressure heating unit side and then connected to the circulating water outlet of the third heat network return water cooler 18. The system of the present application further includes: a second circulating water pump 26; the circulating water inlet of the second condenser 24 is connected to the circulating water outlet of the cooling tower 25 on the non-high back pressure heating unit side through the second circulating water pump 26.

[0077] Usually, the circulation volume of the circulating water cooled by the cooling tower 25 on the non-high back-pressure heating unit side is relatively abundant. Therefore, in the present application, when the circulation volume of the circulating water on the non-high back-pressure heating unit side is relatively abundant, but has not reached the level where the circulating water pump needs to be stopped, the circulating water entering the third heat network return water cooler 18 can also use the cooling tower 25 on the non-high back-pressure heating unit side to adjust the amount of water entering the third heat network return water cooler 18, thereby achieving cold end optimization of the high back-pressure heating unit. For example, the circulating water output from the circulating water outlet of the user end 19 first enters the circulating water inlet of the second condenser 24 through the circulating water inlet of the third heat network return water cooler 18. Under the action of the second circulating water pump 26, the circulating water enters the cooling tower 25 for cooling, and then is transported to the third heat network return water cooler 18. The cooled circulating water is transported to the first condenser 13 through the circulating water outlet of the third heat network return water cooler 18, thereby reducing the temperature of the circulating water transported to the first condenser 13.

[0078] In a specific example of the present application, in order to control the circulating water entering each heat network return water cooler, the system of the present application also includes: a first temperature sensor, a first solenoid valve, a second solenoid valve and a third solenoid valve; the first temperature sensor is arranged in the circulating water outlet of the user end 19, and is used to collect the circulating water temperature at the circulating water outlet of the user end 19; the first solenoid valve is arranged between the circulating water outlet of the user end 19 and the circulating water inlet of the first heat network return water cooler 16, and is used to adjust the circulating water flow entering the first heat network return water cooler 16; the second solenoid valve is arranged between the circulating water outlet of the user end 19 and the circulating water inlet of the second heat network return water cooler 17, and is used to adjust the circulating water flow entering the second heat network return water cooler 17; the third solenoid valve is arranged between the circulating water outlet of the user end 19 and the circulating water inlet of the third heat network return water cooler 18, and is used to adjust the circulating water flow entering the third heat network return water cooler 18.

[0079] The circulating water temperature collected by the first temperature sensor is sent to the controller in real time, and the controller calls the preset algorithm to control different solenoid valves according to the actual temperature of the circulating water from the user end 19, thereby realizing the control of the circulating water flow entering different heat network return water coolers. The controller can be an independently set controller, or it can directly use the existing PLC system to realize the flow control of circulating water, which is not limited here.

[0080] like Figure 3 As shown, the second aspect of the present application provides a high back pressure heat supply regulation method, using the above-mentioned high back pressure heat supply regulation system, the method comprises:

[0081] S100, determining a target temperature of the circulating water entering the first condenser 13, and obtaining an actual temperature of the circulating water collected by the first temperature sensor;

[0082] S200, calculating the temperature difference between the actual temperature and the target temperature of the circulating water entering the first condenser 13, and determining at least one of the first heating network return water cooler 16, the second heating network return water cooler 17 and the third heating network return water cooler 18 as the target heating network return water cooler based on the temperature difference;

[0083] S300, determining a target temperature of a circulating water outlet of a corresponding target heat network return water cooler based on a target temperature of the circulating water entering the first condenser 13;

[0084] S400. Call the flow prediction model corresponding to the corresponding target heating network return water cooler, take the target temperature and actual temperature of the circulating water outlet of the corresponding target heating network return water cooler as input, output the predicted flow of circulating water entering the corresponding target heating network return water cooler through the corresponding flow prediction model, and control the opening of the solenoid valve between the circulating water outlet of the user end 19 and the circulating water inlet of the corresponding heating network return water cooler according to the obtained predicted flow, so that the circulating water flow entering the corresponding heating network return water cooler matches the obtained predicted flow.

[0085] It can be understood that the method of the present application can be built into an independently configured controller or a controller of an existing PLC system in the form of a functional module, and this is not limited here.

[0086] In step S100, the target temperature of the circulating water entering the first condenser 13 may be preset. For example, the target temperature of the circulating water entering the first condenser 13 may be set to 40°.

[0087] In step S200, at least one of the first heating network return water cooler 16, the second heating network return water cooler 17 and the third heating network return water cooler 18 is determined as a target heating network return water cooler based on the temperature difference, including:

[0088] S210, if the temperature difference is lower than the first temperature difference threshold, determine the first heat network return water cooler 16 or the second heat network return water cooler 17 as the target heat network return water cooler. For example, if the difference between the actual temperature collected by the temperature sensor and the target temperature is lower than the preset first temperature difference threshold, the cooling demand of the circulating water is low at this time, and the first heat network return water cooler 16 or the second heat network return water cooler 17 is determined as the target heat network return water cooler. It can be understood that, usually, the actual temperature of the circulating water from the user end 19 is higher than the target temperature of the circulating water entering the first condenser 13. If the actual temperature of the circulating water from the user end 19 is lower than the target temperature of the circulating water entering the first condenser 13, there is no need to perform additional cooling control on the circulating water at the user end 19. For example, in this case, it is sufficient to control the circulating water from the user end 19 to enter the first condenser 13 through the first heat network return water cooler 16 or the second heat network return water cooler 17.

[0089] S220, if the temperature difference is not lower than the first temperature difference threshold, and the temperature difference is lower than the second temperature difference threshold, the first heating network return water cooler 16 and the second heating network return water cooler 17 are determined as the target heating network return water cooler. In this case, if the temperature difference is not lower than the first temperature difference threshold but lower than the second temperature difference threshold, it means that the temperature of the circulating water from the user end 19 is higher than that in step S210, and the cooling demand of the circulating water at this time is higher than that in step S210, then the first heating network return water cooler 16 and the second heating network return water cooler 17 are determined as the target heating network return water cooler.

[0090] S230, if the temperature difference is not lower than the second temperature difference threshold, and the temperature difference is lower than the third temperature difference threshold, determine the first heat network return water cooler 16 or the second heat network return water cooler 17 as the target heat network return water cooler, and determine the third heat network return water cooler 18 as the target heat network return water cooler. In this case, if the temperature difference is not lower than the second temperature difference threshold but lower than the third temperature difference threshold, it means that the temperature of the circulating water from the user end 19 is higher than that in step S220, then the cooling demand of the circulating water is higher than that in step S220, and determine one of the first heat network return water cooler 16 or the second heat network return water cooler 17, and the third heat network return water cooler 18 as the target heat network return water cooler.

[0091] S240, if the temperature difference is not lower than the third temperature difference threshold, determine the first heat network return water cooler 16, the second heat network return water cooler 17 and the third heat network return water cooler 18 as the target heat network return water cooler. In this case, if the temperature difference is not lower than the third temperature difference threshold, it means that the temperature of the circulating water from the user end 19 is higher than that in step S230, and the cooling demand of the circulating water at this time is higher than that in step S230, then determine the first heat network return water cooler 16, the second heat network return water cooler 17 and the third heat network return water cooler 18 as the target heat network return water cooler.

[0092] It can be understood that each temperature difference threshold can be set according to actual conditions.

[0093] In step S300, the target temperature of the circulating water outlet of the corresponding target heat network return water cooler is determined based on the target temperature of the circulating water entering the first condenser 13, including:

[0094] S310: In the case where there are one or more corresponding heat network return water coolers, determine the target temperature of the circulating water entering the first condenser 13 as the target temperature of the circulating water outlet of the corresponding heat network return water cooler. For example, if the corresponding heat network return water cooler includes the first heat network return water cooler 16 and the second heat network return water cooler 17, the target temperature of the circulating water entering the first condenser 13, for example, 40°, is used as the target temperature of the circulating water outlet of the first heat network return water cooler 16 and the second heat network return water cooler 17, that is, the target temperature of the circulating water outlet of the first heat network return water cooler 16 is 40°, and the target temperature of the circulating water outlet of the second heat network return water cooler 17 is also 40°.

[0095] S320, or, in the case where there are multiple corresponding heat network return water coolers, determine the target temperature of the circulating water outlet of the corresponding heat network return water cooler at the target temperature of the circulating water entering the first condenser 13 according to a preset ratio. According to the cooling capacity of different heat network return water coolers, the preset ratio of the target temperature of the circulating water outlet of different heat network return water coolers is pre-set.

[0096] For example, the preset ratio of the target temperature of the circulating water outlet of each heat network return water cooler can be calculated according to the formula Determine, where T final It represents the water temperature after mixing, that is, the target temperature of the circulating water entering the first condenser 13 of the present application, m1 represents the mass of the first water used for mixing, T1 represents the temperature of the first water used for mixing, m2 represents the mass of the second water used for mixing, and T2 represents the temperature of the second water used for mixing.

[0097] It can be understood that if there are three types of mixed water, for example, the inlet water of the first condenser 13 comes from the first heat network return water cooler 16, the second heat network return water cooler 17 and the third heat network return water cooler 18, then the preset ratio of the target temperature of the circulating water outlet of each heat network return water cooler can be calculated according to the formula Determine, where m3 represents the mass of the third water used for mixing, and T3 represents the temperature of the third water used for mixing. In this application, in order to simplify the calculation, the mass of the different circulating water mixed by the user is made the same. Then, in this application, different preset ratios can be set according to the cooling capacity of each heat network return water cooler. For example, each preset ratio is X1%, X2% and X3%. Then, the target temperature of the circulating water outlet of each heat network return water cooler is T final ×(m1+m2+m3)×X i %, since m1, m2, and m3 are considered the same, the target temperature of the circulating water outlet of each heat network return water cooler can be simplified to T final ×3×X i %. For example, T final is 40°, X1% is 30%, X2% is 30%, X3% is 40%, X1%, X2% and X3% respectively correspond to the preset ratio of the target temperature of the circulating water outlet of the first hot network return water cooler 16, the preset ratio of the target temperature of the circulating water outlet of the second hot network return water cooler 17 and the preset ratio of the target temperature of the circulating water outlet of the third hot network return water cooler 18. Then, the target temperature of the circulating water outlet of the first hot network return water cooler 16 is 36°, the target temperature of the circulating water outlet of the second hot network return water cooler 17 is 36°, and the target temperature of the circulating water outlet of the third hot network return water cooler 18 is 48°.

[0098] In step S400, the steps of constructing each corresponding traffic prediction model include:

[0099] S410. Obtain the historical target temperature of the circulating water outlet of the corresponding target heating network return water cooler, the historical actual temperature of the circulating water entering the target heating network return water cooler corresponding to each historical target temperature, and the historical actual flow rate of the circulating water entering the corresponding target heating network return water cooler corresponding to each historical target temperature and each historical actual temperature.

[0100] For example, taking the first target heat network return water cooler as an example, obtain the historical target temperature of the first target heat network return water cooler at different circulating water outlets within a preset period, such as half a year, the historical actual temperature corresponding to each historical target temperature, and the historical actual flow rate of circulating water entering the corresponding target heat network return water cooler corresponding to each historical target temperature and each historical actual temperature to construct a training sample set. Among them, the historical actual flow rate can be detected by a flow meter set at the water inlet of the corresponding target heat network return water cooler, or a mapping relationship between the flow rate and the corresponding solenoid valve opening is pre-established to directly convert the flow rate entering the corresponding target heat network return water cooler into the opening of the corresponding solenoid valve. For example, the constructed training sample set can be {(Ta1, Tb1, W1), (Ta1, Tb1, W1), ..., (Tan, Tbn, Wn)}, where Tan represents the historical target temperature of the circulating water outlet of the first target thermal network return water cooler at the nth sampling moment, Tbn represents the historical actual temperature of the circulating water entering the first target thermal network return water cooler at the nth sampling moment, and Wn represents the flow rate of the circulating water entering the first target thermal network return water cooler at the nth sampling moment, or the valve opening of the first solenoid valve.

[0101] S420, using the historical target temperature of the circulating water outlet of the corresponding target heat network return water cooler and the corresponding historical actual temperature as the input of the preset neural network, outputting the predicted flow of circulating water entering the corresponding target heat network return water cooler through the preset neural network, or outputting the valve opening of the solenoid valve corresponding to the corresponding target heat network return water cooler, adjusting the network parameters of the preset neural network based on the obtained predicted flow or valve opening of the solenoid valve, and the corresponding historical actual flow of circulating water entering the corresponding target heat network return water cooler, until the preset neural network meets the convergence conditions, and obtaining the corresponding flow prediction model of the target heat network return water cooler, wherein the convergence conditions may be that the prediction accuracy reaches a threshold, or the model reaches the number of iterations. In the present application, the preset neural network may be a convolutional neural network, a BP neural network, a recurrent neural network, etc., which are not limited here.

[0102] In the present application, the corresponding flow prediction model is obtained by training for different target heat network return water coolers, for example, the first flow prediction model of the first target heat network return water cooler is constructed, the second flow prediction model of the second target heat network return water cooler is constructed, and the third flow prediction model of the third target heat network return water cooler is constructed. By constructing corresponding flow prediction models for different target heat network return water coolers, the circulating water flow of different heat network return water coolers can be dynamically and real-time controlled according to the outlet water temperature of the user-side circulating water and the target temperature of the circulating water inlet of the first condenser, so that the waste heat of the user-side circulating water can be reused more accurately and effectively, and the circulating water temperature entering the first condenser can be reduced. At the same time, the regulating system including multiple heat network return water coolers constructed by the present application can make full use of the waste heat of the user-side circulating water to heat the boiler secondary air and condensate feed water, and can make full use of the circulation margin of the cooling tower on the non-high back pressure heating unit side, without the need to additionally start the cooling tower on the high back pressure heating unit side to cool the circulating water, thereby effectively reducing energy consumption and improving energy utilization.

[0103] Specifically, the construction steps of the regulation system of the present application include: building a thermal system simulation model of a high back-pressure heating unit and a cylinder cutting heating unit, obtaining the high back-pressure heating and cylinder cutting heating capacities through variable operating condition calculations of the unit units, and determining the high back-pressure combined cylinder cutting heating temperature characteristics and the restricted electric load areas during different heating periods. Determine the influence of the return water parameters of the heating system's heat network on the back pressure and power supply load, construct a thermoelectric flexible regulation system based on the coordinated optimization of the cold end of the unit units, build a new heat exchanger for regulating the return water temperature of the heat network, introduce circulating cooling water as a cold source, and form a high back-pressure heating unit and a steam extraction heating unit cold end coordinated optimization system. Reduce the coal consumption of the steam extraction heating unit through optimized allocation, and improve the thermoelectric regulation flexibility of the high back-pressure heating unit. Based on the pre-developed low-grade thermal energy utilization system of heating network return water, the temperature control method of heating recycled water, condensate make-up water, etc. of heating network return water is studied to obtain the temperature change characteristics of recycled water, condensate make-up water, etc.; the temperature drop characteristics of heating network return water after heating recycled water and condensate make-up water are studied to understand the influence of heating network return water temperature drop on the back pressure of the unit, so as to realize the effective utilization of low-grade thermal energy of heating network return water.

[0104] In summary, the present application can realize flexible regulation of the return water of the heating network by adjusting the circulating water flow entering the return water cooler of the heating network; at the same time, by adjusting the temperature of the return water of the heating network through the return water cooler of the heating network, the back pressure of the high back-pressure heating unit can be flexibly adjusted, thereby solving the influence of the excessive back pressure of the unit on the top load of the unit and improving the top load capacity of the high back-pressure heating unit; through the regulating effect of the return water of the heating network by the return water cooler of the heating network, the wet-cooling cogeneration unit with low heating load and small circulating water flow of the heating network can be equipped with high back-pressure heating capability; the present application also avoids the problem of high back-pressure heating by utilizing the circulating cooling water of non-high back-pressure heating units to enter the return water cooler of the heating network. The startup and operation of the circulating water pump of the high back-pressure heating unit reduces the loss of operating equipment and the power consumption of the circulating water pump; the present application increases the flexibility of back-pressure regulation of the high back-pressure heating unit and utilizes the waste heat of the heating network return water by introducing the recycled water and condensate feed water into the heating network return water cooler and utilizing the heating network return water to heat and recover the heat of the heating network return water; the present application utilizes the heating network return water to heat the secondary air of the boiler, thereby replacing the heating steam consumed by the secondary air heater, thereby effectively improving the energy utilization rate; in addition, the present application can achieve cold-end optimization of the non-high back-pressure heating unit by adjusting the circulating water flow between the high back-pressure heating unit and the non-high back-pressure heating unit.

[0105] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0106] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A high back pressure heating regulation system, characterized in that: include: A high back pressure heating unit, a non-high back pressure heating unit, a first condenser, a second condenser, a heating network heater and at least one heating network return water cooler; The steam exhaust port of the high back pressure heating unit is connected to the steam inlet of the first condenser, the circulating water outlet of the first condenser is connected to the circulating water inlet of the heating network heater, the circulating water outlet of the heating network heater is connected to the circulating water inlet of the user end, and the steam inlet of the heating network heater is also connected to the steam exhaust port of the non-high back pressure heating unit; The steam exhaust port of the non-high back pressure heating unit is also connected to the steam inlet of the second condenser, the circulating water inlet of the second condenser is connected to the circulating water outlet of the cooling tower on the non-high back pressure heating unit side, and the circulating water outlet of the second condenser is connected to the circulating water inlet of the cooling tower on the non-high back pressure heating unit side; The circulating water outlet at the user end is connected to the at least one heat network return water cooler, and the at least one heat network return water cooler is used to cool the circulating water from the user end by heat exchange with a designated heat exchange target, and then transport the cooled circulating water to the circulating water inlet of the first condenser.

2. The high back pressure heat supply and regulation system according to claim 1, characterized in that: The at least one heat network return water cooler comprises: The first heat network return water cooler; The circulating water outlet of the user end is connected to the circulating water inlet of the first heat network return water cooler, and the circulating water outlet of the first heat network return water cooler is connected to the circulating water inlet of the first condenser; The specified heat exchange target includes: Secondary air of boiler; The first heat network return water cooler is used to heat the secondary air of the boiler.

3. The high back pressure heat supply and regulation system according to claim 2, characterized in that: The at least one heat network return water cooler comprises: Second heat network return water cooler; The circulating water outlet of the user end is connected to the circulating water inlet of the second heat network return water cooler, and the circulating water outlet of the second heat network return water cooler is connected to the circulating water inlet of the first condenser; The specified heat exchange target includes: Condenser water replenishment; The second heat network return water cooler is used to heat the condenser feed water.

4. The high back pressure heat supply and regulation system according to claim 3, characterized in that: The at least one heat network return water cooler comprises: The third heat network return water cooler; The circulating water outlet of the user end is connected to the circulating water inlet of the third heat network return water cooler, and the circulating water outlet of the third heat network return water cooler is connected to the circulating water inlet of the first condenser; The specified heat exchange target includes: Cooling tower on the non-high back pressure heating unit side; The circulating water inlet of the second condenser is connected to the circulating water outlet of the cooling tower on the non-high back pressure heating unit side, and is also connected to the circulating water inlet of the third heat network return water cooler. The circulating water outlet of the third condenser is connected to the circulating water inlet of the cooling tower on the non-high back pressure heating unit side, and is also connected to the circulating water outlet of the third heat network return water cooler.

5. The high back pressure heat supply and regulation system according to claim 1, characterized in that: The system further comprises: A first circulating water pump and a second circulating water pump; The circulating water outlet of the first condenser is connected to the circulating water inlet of the heating network heater through the first circulating water pump; The circulating water inlet of the second condenser is connected to the circulating water outlet of the cooling tower on the non-high back pressure heating unit side through the second circulating water pump.

6. The high back pressure heat supply and regulation system according to claim 4, characterized in that: The system further comprises: A first temperature sensor, a first solenoid valve, a second solenoid valve and a third solenoid valve; The first temperature sensor is disposed in the circulating water outlet of the user end, and is used to collect the circulating water temperature at the circulating water outlet of the user end; The first solenoid valve is arranged between the circulating water outlet of the user end and the circulating water inlet of the first heat network return water cooler, and is used to adjust the circulating water flow entering the first heat network return water cooler; The second solenoid valve is arranged between the circulating water outlet of the user end and the circulating water inlet of the second heat network return water cooler, and is used to adjust the circulating water flow entering the second heat network return water cooler; The third solenoid valve is arranged between the circulating water outlet of the user end and the circulating water inlet of the third heat network return water cooler, and is used to adjust the circulating water flow entering the third heat network return water cooler.

7. A high back pressure heat supply regulation method, characterized in that: Using the high back pressure heat regulation system described in claim 6, the method comprises: Determine the target temperature of the circulating water entering the first condenser, and obtain the actual temperature of the circulating water collected by the first temperature sensor; Calculating the temperature difference between the actual temperature and the target temperature of the circulating water entering the first condenser, and determining at least one of the first heating network return water cooler, the second heating network return water cooler, and the third heating network return water cooler as the target heating network return water cooler based on the temperature difference; Determine the target temperature of the circulating water outlet of the corresponding target heat network return water cooler based on the target temperature of the circulating water entering the first condenser; A flow prediction model corresponding to a corresponding target heating network return water cooler is called, and the target temperature of the circulating water outlet of the corresponding target heating network return water cooler and the actual temperature are taken as inputs. The corresponding flow prediction model outputs the predicted flow of circulating water entering the corresponding target heating network return water cooler, and the opening of the solenoid valve arranged between the circulating water outlet at the user end and the circulating water inlet of the corresponding heating network return water cooler is controlled according to the obtained predicted flow, so that the circulating water flow entering the corresponding heating network return water cooler matches the obtained predicted flow.

8. The high back pressure heat supply regulation method according to claim 7, characterized in that: Determining at least one of the first heating network return water cooler, the second heating network return water cooler, and the third heating network return water cooler as a target heating network return water cooler based on the temperature difference includes: If the temperature difference is lower than a first temperature difference threshold, determining the first heating network return water cooler or the second heating network return water cooler as a target heating network return water cooler; If the temperature difference is not lower than the first temperature difference threshold, and the temperature difference is lower than the second temperature difference threshold, determining the first heating network return water cooler and the second heating network return water cooler as target heating network return water coolers; If the temperature difference is not lower than the second temperature difference threshold, and the temperature difference is lower than the third temperature difference threshold, determining the first heating network return water cooler or the second heating network return water cooler as the target heating network return water cooler, and determining the third heating network return water cooler as the target heating network return water cooler; If the temperature difference is not lower than the third temperature difference threshold, the first heating network return water cooler, the second heating network return water cooler and the third heating network return water cooler are determined as target heating network return water coolers.

9. The high back pressure heat supply regulation method according to claim 7, characterized in that: Determining a target temperature of a circulating water outlet of a corresponding target heat network return water cooler based on a target temperature of the circulating water entering the first condenser includes: In the case where there are one or more corresponding heat network return water coolers, determining the target temperature of the circulating water entering the first condenser as the target temperature of the circulating water outlet of the corresponding heat network return water cooler; or When there are multiple return water coolers corresponding to the heat network, the target temperature of the circulating water outlet of the return water cooler corresponding to the heat network is determined according to a preset ratio at the target temperature of the circulating water entering the first condenser.

10. The high back pressure heat supply regulation method according to claim 7, characterized in that: The steps to build a traffic prediction model include: Obtain the historical target temperature of the circulating water outlet of the corresponding target heat network return water cooler, the historical actual temperature corresponding to each historical target temperature, and the historical actual flow rate of the circulating water entering the corresponding target heat network return water cooler corresponding to each historical target temperature and each historical actual temperature; The historical target temperature of the circulating water outlet of the corresponding target heat network return water cooler and the corresponding historical actual temperature are used as the input of the preset neural network, and the predicted flow rate of the circulating water entering the corresponding target heat network return water cooler is output by the preset neural network. Based on the obtained predicted flow rate and the corresponding historical actual flow rate of the circulating water entering the corresponding target heat network return water cooler, the network parameters of the preset neural network are adjusted until the preset neural network meets the convergence conditions, and the corresponding flow prediction model of the target heat network return water cooler is obtained.

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