Steam production system and control method thereof

Abstract

The invention provides a steam production system and a control method thereof. The system comprises a low-temperature heat storage tank, a high-temperature heat storage tank, a first assembly with a first flash evaporation unit, a second flash evaporation unit and an electric heat pump unit. A water inlet and a water outlet of the first flash evaporation unit are connected with a water inlet and a water outlet of the first assembly respectively, and the water inlet of the first assembly is used for being connected with a heat source water supply pipeline; a first connector of the low-temperature heat storage tank is connected with a water outlet of the first assembly and an evaporator inlet of the electric heat pump unit, and a second connector of the low-temperature heat storage tank is connected with an evaporator outlet of the electric heat pump unit and used for being connected with a heat source water return pipeline. A first interface of the high-temperature heat storage tank is connected with a condenser outlet of the electric heat pump unit and a water inlet of the second flash evaporation unit, and a second interface of the high-temperature heat storage tank is connected with a condenser inlet of the electric heat pump unit and a water outlet of the second flash evaporation unit; a steam outlet of the first flash evaporation unit and a steam outlet of the second flash evaporation unit are both used for being connected with a steam conveying pipeline.

Description

Technical Field

[0001] The present application relates to the field of industrial heat technology, and in particular to a steam production system and a control method thereof. Background Art

[0002] Industrial heat mainly includes heating, distillation, drying, sterilization and other processes, accounting for more than 60% of the energy consumption structure of most industrial industries. At present, industrial heat mainly comes from decentralized coal-fired / gas-fired boilers and centralized steam transportation of cogeneration. Among them, decentralized boiler heating generally adopts the mode of high-pressure production and terminal throttling, which seriously wastes high-quality energy. As for centralized steam transportation of cogeneration, because thermal power plants are often far away from heat users, during long-distance transportation, due to pipeline heat dissipation and resistance along the way, the temperature, pressure and other parameters of steam will change greatly, which limits the development and application of long-distance steam transportation systems. Therefore, water vapor conversion technology that supplies high-quality steam by recycling low-temperature waste heat in the factory or by long-distance heating of hot water and reusing flash evaporation or flash evaporation after compression at the user has also been proposed. Although the problems of grade mismatch and transportation difficulties have been solved, the technology has not been applied and promoted in the field of industrial heating due to high power consumption and high cost.

[0003] In recent years, the installed capacity of renewable energy has gradually increased. The intermittent, volatile and random characteristics of renewable energy generation will lead to the redundancy of wind power and photovoltaic power, resulting in serious "wind abandonment" and "light abandonment" phenomena, which will also have a great impact on the regulation of the power grid system. Therefore, it is very important to improve the utilization efficiency of heat source water, increase the amount of steam preparation, absorb electricity during low electricity price periods, and reduce electricity consumption during high electricity price periods. Summary of the invention

[0004] The purpose of the present application is to provide a steam production system and a control method thereof, which can improve the economy of the steam production system and enhance the regulation capability of peak shaving and valley filling.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] Technical Solution 1: A steam production system, comprising a low-temperature heat storage tank, a high-temperature heat storage tank, a first component having a first flash unit, a second flash unit and an electric heat pump unit, wherein the first component has a water inlet and a water outlet, wherein:

[0007] The water inlet and the water outlet of the first flash unit are respectively connected to the water inlet and the water outlet of the first component, and the water inlet of the first component is used to connect to the heat source water supply pipeline;

[0008] The first interface of the low-temperature heat storage tank is connected to the water outlet of the first component and the evaporator inlet of the electric heat pump unit, and the second interface of the low-temperature heat storage tank is connected to the evaporator outlet of the electric heat pump unit and is used to connect to the heat source return water pipeline;

[0009] The first interface of the high-temperature heat storage tank is connected to the condenser outlet of the electric heat pump unit and the water inlet of the second flash unit, and the second interface of the high-temperature heat storage tank is connected to the condenser inlet of the electric heat pump unit and the water outlet of the second flash unit;

[0010] The steam outlet of the first flash unit and the steam outlet of the second flash unit are both used to be connected to a steam delivery pipeline.

[0011] Technical Solution 2: In the steam production system according to Technical Solution 1, the first component further comprises a heat exchange unit, and the water inlet and the water outlet of the first flash unit are respectively connected to the water inlet and the water outlet of the first component through the heat exchange unit, wherein:

[0012] The first interface and the second interface of the heat exchange unit are respectively connected to the water inlet and the water outlet of the first component, and the third interface and the fourth interface of the heat exchange unit are respectively connected to the water inlet and the water outlet of the first flash unit.

[0013] Technical Solution 3: The steam production system as described in Technical Solution 1 further includes a compressor unit, wherein:

[0014] The steam inlet of the compressor unit is connected to the steam outlet of any one of the first flash unit and the second flash unit, and the steam outlet of the compressor unit is used to be connected to the steam delivery pipeline.

[0015] Technical Solution 4: As the steam production system described in Technical Solution 3, any one of the first flash unit and the second flash unit comprises a multi-stage flash evaporator, and the multi-stage flash evaporators are sequentially connected in series, wherein the water inlet of the first-stage flash evaporator and the water outlet of the last-stage flash evaporator serve as the water inlet and water outlet of the flash unit respectively, and the water outlet and water inlet of the two adjacent flash evaporators are connected;

[0016] The compressor unit comprises a multi-stage compressor, which is connected in series in sequence, wherein the steam outlet of each stage of the flash evaporator is respectively connected to the steam inlet of the corresponding first stage of the compressor, and the steam outlet and steam inlet of two adjacent stages of the compressor are connected.

[0017] Technical Solution 5: In the steam production system described in Technical Solution 1, the electric heat pump unit includes a multi-stage electric heat pump, and the multi-stage electric heat pumps are connected in series in sequence, wherein:

[0018] The first interface and the second interface of the low-temperature heat storage tank are respectively connected to the evaporator inlet of the first-stage electric heat pump and the evaporator outlet of the last-stage electric heat pump, and the evaporator inlet and evaporator outlet of the electric heat pumps of two adjacent stages are connected;

[0019] The first interface and the second interface of the high-temperature heat storage tank are respectively connected to the condenser outlet of the first-stage electric heat pump and the condenser inlet of the last-stage electric heat pump, and the condenser inlet and condenser outlet of the two adjacent stages of the electric heat pump are connected.

[0020] Technical Solution 6: In the steam production system as described in any one of Technical Solutions 1 to 5, a first valve is provided in the connecting pipeline of the evaporator outlet of the electric heat pump unit; a second valve is provided in the connecting pipeline of the condenser inlet of the electric heat pump unit; and a third valve is provided in the pipeline at at least one of the first interface and the second interface of the high-temperature heat storage tank.

[0021] Technical Solution 7: The steam production system as described in Technical Solution 6, wherein the steam production system has at least one operating mode among a first operating mode, a second operating mode and a third operating mode, wherein:

[0022] In the first operation mode, the first valve and the second valve are closed, the third valve is opened, the electric heat pump unit stops running, and the low-temperature heat storage tank and the high-temperature heat storage tank are disconnected from the electric heat pump unit;

[0023] In the second operation mode, the first valve, the second valve and the third valve are all opened, and the electric heat pump unit operates normally, wherein the low-temperature heat storage tank releases heat and the high-temperature heat storage tank stores heat;

[0024] In the third operation mode, the first valve and the second valve are opened, the third valve is closed, and the electric heat pump unit partially operates, wherein the low-temperature heat storage tank does not release heat and the high-temperature heat storage tank does not store heat.

[0025] Technical Solution 8: For the steam production system as described in Technical Solution 7, during the peak electricity price period, the steam production system is in the first operating mode; during the valley electricity price period, the steam production system is in the second operating mode; during the flat electricity price period, the steam production system is in the third operating mode.

[0026] Technical Solution 9: A control method for a steam production system, the steam production system comprising a low-temperature heat storage tank, a high-temperature heat storage tank, a first component having a first flash unit, a second flash unit and an electric heat pump unit, the control method comprising:

[0027] During the peak electricity price period, the steam production system is controlled to be in a first operation mode, wherein in the first operation mode, the electric heat pump unit is controlled to stop operating, the low-temperature heat storage tank and the high-temperature heat storage tank are both disconnected from the electric heat pump unit, and the steam flashed by the first flash unit and the high-temperature water stored in the high-temperature heat storage tank flashed by the second flash unit enter the steam delivery pipeline together;

[0028] During the valley electricity price period, the steam production system is controlled to be in the second operation mode, wherein, in the second operation mode, the electric heat pump unit is controlled to operate normally, the low-temperature heat storage tank and the high-temperature heat storage tank are both connected to the electric heat pump unit, the low-temperature water cooled by the first component is mixed with the outlet water of the low-temperature heat storage tank and enters the electric heat pump unit, a part of the hot water heated by the electric heat pump unit enters the second flash unit, and another part of the hot water is stored in the high-temperature heat storage tank, and the steam flashed by the second flash unit and the steam flashed by the first flash unit enter the steam delivery pipeline together.

[0029] Technical Solution 10: The control method according to Technical Solution 9, further comprising:

[0030] During the period of flat electricity price, the steam production system is controlled to be in a third operation mode, wherein in the third operation mode, the electric heat pump unit is controlled to partially operate, the electric heat pump unit is disconnected from the high-temperature heat storage tank, the low-temperature water cooled by the first component enters the electric heat pump unit, the hot water heated by the electric heat pump unit enters the second flash unit, the steam flashed by the second flash unit and the steam flashed by the first flash unit enter the steam delivery pipeline together, wherein the low-temperature heat storage tank does not release heat, and the high-temperature heat storage tank does not store heat.

[0031] Technical Solution 11: According to the control method of Technical Solution 9 or 10, the steam production system further includes a compressor unit, and the control method further includes:

[0032] The steam flashed by any one of the first flash unit and the second flash unit is further compressed by the compressor unit and then enters the steam delivery pipeline.

[0033] Technical Solution 12: According to the control method of Technical Solution 9 or 10, the first component further comprises a heat exchange unit, and the control method further comprises:

[0034] Before the hot water is flashed in the first flash unit in the first component, the hot water is input into the heat exchange unit in the first component to exchange heat with the flash return water after the flash in the first flash unit. The hot water heated by the heat exchange unit enters the first flash unit for flashing.

[0035] The low-temperature water cooled by the first component includes: the low-temperature water cooled by heat exchange in the heat exchange unit.

[0036] The steam production system and control method thereof provided by one or more technical solutions of the present application adopt different methods to achieve cascade utilization according to different grades of heat source water, thereby making full use of heat and improving overall efficiency.

[0037] The steam production system and control method thereof provided by one or more technical solutions of the present application utilize a high-temperature heat storage tank, a low-temperature heat storage tank and an electric heat pump unit to transfer electricity from periods of low electricity prices to periods of high electricity prices, thereby facilitating the absorption of renewable energy and the regulation of the power grid.

[0038] The steam production system and control method provided by one or more technical solutions of the present application improve the economy of the steam production system by adjusting the operation strategies in different time periods, changing the equipment operation mode in different electricity price periods, using more electricity in low electricity price periods, and reducing electricity in high electricity price periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic structural diagram of the steam production system of the first embodiment of the present application.

[0040] Figure 2 This is a schematic structural diagram of a steam production system according to a second embodiment of the present application.

[0041] Figure 3 This is a schematic structural diagram of a steam production system according to the third embodiment of the present application.

[0042] Figure 4 This is a schematic structural diagram of a steam production system according to a fourth embodiment of the present application.

[0043] Figure 5 This is a schematic structural diagram of a steam production system according to the fifth embodiment of the present application.

[0044] Figure 6 This is a schematic structural diagram of a steam production system according to the sixth embodiment of the present application.

[0045] Figure 7 This is a schematic diagram of the state of the steam production system of the present application in the first operating mode.

[0046] Figure 8This is a schematic diagram of the state of the steam production system of the present application in the second operating mode.

[0047] Fig. 9 This is a schematic diagram of the status of the steam production system of the present application in the third operating mode. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0049] This application proposes a steam production system and a control method thereof, which optimizes the system process of using hot water to produce industrial steam, and proposes corresponding operation modes in different power consumption periods. The hot water transmission technology is mature and reliable, and the water transmission and steam production technology is environmentally friendly and has significantly improved thermal efficiency. In addition, while retaining the advantages of water transmission and steam production, this application reduces the heating cost of the system, improves the absorption capacity of renewable energy, and reduces the "wind and solar abandonment" phenomenon caused by the volatility and intermittent characteristics of renewable energy, thereby broadening the application prospects of water transmission and steam production technology.

[0050] The steam production system and control method thereof of various embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0051] First embodiment

[0052] Figure 1 The structural schematic diagram of the steam production system of the first embodiment of the present application is disclosed. Figure 1 As shown, the steam production system includes a low-temperature heat storage tank 1, a first component 2, a second flash unit 3, an electric heat pump unit 4 and a high-temperature heat storage tank 5.

[0053] The first component 2 has a water inlet 201 and a water outlet 202. The first component 2 includes a first flash unit 21. The water inlet and the water outlet of the first flash unit 21 are respectively connected to the water inlet 201 and the water outlet 202 of the first component 2. The water inlet 201 of the first component 2 is used to connect to the heat source water supply pipeline 71.

[0054] The low-temperature heat storage tank 1 has a first interface 11 and a second interface 12. The first interface 11 of the low-temperature heat storage tank 1 is connected to the water outlet 202 of the first component 2 and the evaporator inlet of the electric heat pump unit 4, and the second interface 12 of the low-temperature heat storage tank 1 is connected to the evaporator outlet of the electric heat pump unit 4 and is used to connect to the heat source return water pipeline 72.

[0055] The high temperature heat storage tank 5 has a first interface 51 and a second interface 52. The first interface 51 of the high temperature heat storage tank 5 is connected to the condenser outlet of the electric heat pump unit 4 and the water inlet of the second flash unit 3, and the second interface 52 of the high temperature heat storage tank 5 is connected to the condenser inlet of the electric heat pump unit 4 and the water outlet of the second flash unit 3.

[0056] The steam outlet of the first flash unit 21 and the steam outlet of the second flash unit 3 are both used to be connected to the steam delivery pipeline 73 , and the steam is supplied to the user through the steam delivery pipeline 73 .

[0057] Second embodiment

[0058] Figure 2 The structural schematic diagram of the steam production system of the second embodiment of the present application is disclosed. Figure 2 As shown, Figure 2 The steam production system shown is similar to Figure 1 The steam generation system shown differs in that Figure 2 In the steam production system shown, the first component 2 further includes a heat exchange unit 22 , and the water inlet and the water outlet of the first flash unit 21 are respectively connected to the water inlet 201 and the water outlet 202 of the first component 2 through the heat exchange unit 22 .

[0059] The heat exchange unit 22 has a first interface 221, a second interface 222, a third interface 223 and a fourth interface 224. The first interface 221 and the second interface 222 of the heat exchange unit 22 are respectively connected to the water inlet 201 and the water outlet 202 of the first component 2, and the third interface 223 and the fourth interface 224 of the heat exchange unit 22 are respectively connected to the water inlet and the water outlet of the first flash unit 21.

[0060] Third embodiment

[0061] Figure 3 The structural schematic diagram of the steam production system of the third embodiment of the present application is disclosed. Figure 3 As shown, Figure 3 The steam production system shown is similar to Figure 2 The steam production system shown differs in that Figure 3 The steam production system shown may further include a compressor unit 6. The steam inlet of the compressor unit 6 is connected to the steam outlet of the first flash unit 21, and the steam outlet of the compressor unit 6 is used to be connected to the steam delivery pipeline 73.

[0062] When the parameters of the steam produced by the first flash evaporation unit 21 are low, the steam produced by the first flash evaporation unit 21 may be further compressed by the compressor unit 6 and then transported to the steam transport pipeline 73 .

[0063] Fourth embodiment

[0064] Figure 4 The structural schematic diagram of the steam production system of the fourth embodiment of the present application is disclosed. Figure 4 As shown, Figure 4 The steam production system shown is similar to Figure 2 The steam production system shown differs in that Figure 4 The steam production system shown may further include a compressor unit 6. The steam inlet of the compressor unit 6 is connected to the steam outlet of the second flash unit 3, and the steam outlet of the compressor unit 6 is used to be connected to the steam delivery pipeline 73.

[0065] When the parameters of the steam produced by the second flash evaporation unit 3 are low, the steam produced by the second flash evaporation unit 3 may be further compressed by the compressor unit 6 and then transported to the steam transport pipeline 73 .

[0066] In combination with the fourth embodiment and the fifth embodiment, the steam inlet of the compressor unit 6 of the present application can be connected to the steam outlet of any one of the first flash unit 21 and the second flash unit 3 according to actual application conditions, and the steam outlet of the compressor unit 6 is used to be connected to the steam delivery pipeline 73.

[0067] Fifth embodiment

[0068] Figure 5 The structural schematic diagram of the steam production system of the fifth embodiment of the present application is disclosed. Figure 5 As shown, Figure 5 The steam production system shown is similar to Figure 4 The steam generation system shown differs in that Figure 5 In the steam production system shown, the second flash unit 3 has multi-stage flash evaporation and the compressor unit 6 has multi-stage compression.

[0069] Specifically, the second flash unit 3 includes a plurality of second flash evaporators 30, which are sequentially connected in series, and the flashed water sequentially passes through the plurality of second flash evaporators 30. The water inlet of the first-stage second flash evaporator 30 and the water outlet of the last-stage second flash evaporator 30 serve as the water inlet and water outlet of the second flash unit 3, respectively, and the water outlets and water inlets of two adjacent second flash evaporators 30 are connected.

[0070] The compressor unit 6 comprises a multi-stage compressor 60, which is connected in series in sequence, and the steam outlet and steam inlet of two adjacent compressors 60 are connected. The steam outlet of each second flash evaporator 30 is connected to the steam inlet of the corresponding first compressor 60.

[0071] Optionally, the multi-stage compressor 60 can be designed with an inter-stage water spraying link to connect the water outlet of each stage of the second flash evaporator 30 with the steam outlet of the corresponding first-stage compressor 60, so that the flash return water of the second flash evaporator 30 can be used to reduce the superheat of the compressor 60 outlet, thereby preventing problems such as carbonization of the compressor 60 lubricating oil and reduction of material stress.

[0072] Optionally, the first flash unit 21 of the present application may also be similar to the case where there are multiple stages of flash evaporation.

[0073] Therefore, any one of the first flash unit 21 and the second flash unit 3 of the present application may include a multi-stage flash evaporator, which is connected in series in sequence, wherein the water inlet of the first-stage flash evaporator and the water outlet of the last-stage flash evaporator are respectively used as the water inlet and water outlet of the flash unit, and the water outlet and water inlet of the adjacent two-stage flash evaporators are connected. The steam outlet of each stage of the flash evaporator is respectively connected to the steam inlet of the corresponding first-stage compressor 6060.

[0074] Sixth embodiment

[0075] Figure 6 The structural schematic diagram of the steam production system of the sixth embodiment of the present application is disclosed. Figure 6 As shown, Figure 6 The steam production system shown is similar to Figure 2 The steam generation system shown differs in that Figure 6 In the steam production system shown, a first valve 81 is provided in the connecting pipeline at the evaporator outlet of the electric heat pump unit 4; a second valve 82 is provided in the connecting pipeline at the condenser inlet of the electric heat pump unit 4; and a third valve 83 is provided in the pipeline at at least one of the first interface 51 and the second interface 52 of the high-temperature heat storage tank 5.

[0076] Of course, it can be understood that the setting form, setting number and setting position of the valves in the steam production system of the present application are not limited to those shown in the drawings of the present application. The steam production system of the present application can also set valves in other connecting pipelines. As long as all valves added play a shut-off role in the system, they will be covered within the protection scope of the present application.

[0077] In the above embodiments, the electric heat pump unit 4 in the steam production system of the present application can be designed as a multi-stage situation, and the electric heat pump unit 4 can include a multi-stage electric heat pump (not shown), and the multi-stage electric heat pumps are connected in series in sequence. Among them, the first interface 11 and the second interface 12 of the low-temperature heat storage tank 1 are respectively connected to the evaporator inlet of the first-stage electric heat pump and the evaporator outlet of the last-stage electric heat pump, and the evaporator inlet and evaporator outlet of the adjacent two-stage electric heat pump are connected; the first interface 51 and the second interface 52 of the high-temperature heat storage tank 5 are respectively connected to the condenser outlet of the first-stage electric heat pump and the condenser inlet of the last-stage electric heat pump, and the condenser inlet and condenser outlet of the adjacent two-stage electric heat pump are connected.

[0078] Similarly, in other embodiments of the present application, the heat exchange unit 22 of the present application may also include multiple stages.

[0079] In addition, it can be understood that the above are only some illustrative embodiments of the steam production system of the present application, however, the embodiments of the steam production system of the present application are not limited thereto, and the schemes shown in the various embodiments of the steam production system shown above in the present application can be combined with each other according to actual conditions. Without departing from the creative essence of the present application, any combination or simple and equivalent transformation of the above embodiments will fall within the protection scope of the present application.

[0080] In some embodiments, the steam production system of the present application may have at least one operation mode among a first operation mode, a second operation mode, and a third operation mode.

[0081] The operation mode of the steam production system of the present application will be described in detail below using the scheme illustrated in the sixth embodiment.

[0082] During peak electricity price periods, the steam production system of the present application may be in a first operation mode, and the steam production system of the present application may use less electricity. Figure 7 The state diagram of the steam production system of the present application in the first operating mode is disclosed. Figure 7 As shown, in the steam production system of the present application, the first valve 81 and the second valve 82 are closed, the third valve 83 is opened, the electric heat pump unit 4 stops running, and the low-temperature heat storage tank 1 and the high-temperature heat storage tank 5 are disconnected from the electric heat pump unit 4.

[0083] The heat source water directly enters the heat exchange unit 22 through the heat source water supply pipeline 71, and the heat source water after heat exchange and cooling enters the low-temperature heat storage tank 1 through the first interface 11 of the low-temperature heat storage tank 1, and the low-temperature water therein is pushed out through the second interface 12 of the low-temperature heat storage tank 1 to the heat source return water pipeline 72. At the same time, the flash return water of the first flash unit 21 heated by the heat exchange unit 22 and the hot water stored in the high-temperature heat storage tank 5 are respectively flashed to produce the required steam and enter the steam delivery pipeline 73.

[0084] During the valley electricity price period, the steam production system of the present application may be in the second operation mode, and the steam production system of the present application may consume more electricity. Figure 8 The state diagram of the steam production system of the present application in the second operation mode is disclosed. Figure 8 As shown, when the steam production system of the present application is in the second operating mode, the first valve 81, the second valve 82 and the third valve 83 are all opened, and the electric heat pump unit 4 operates normally, wherein the low-temperature heat storage tank 1 releases heat and the high-temperature heat storage tank 5 stores heat.

[0085] The heat source water directly enters the heat exchange unit 22 through the heat source water supply pipeline 71. The heat source water after heat exchange and cooling is mixed with the water outlet of the first interface 11 of the low-temperature heat storage tank 1 and enters the evaporator in the electric heat pump unit 4. The water at the outlet of the evaporator of the electric heat pump unit 4 is divided into two streams, one of which enters the low-temperature heat storage tank 1 through the second interface 12 of the low-temperature heat storage tank 1, and the other enters the heat source return water pipeline 72. The heat exchange unit 22 and the electric heat pump unit 4 heat the flash return water of the first flash unit 21 and the flash return water of the second flash unit 3 respectively, and the required steam is produced by flash evaporation and enters the steam delivery pipeline 73. At the same time, the electric heat pump unit 4 also heats the water stored in the high-temperature heat storage tank 5 through the first interface 51 and the second interface 52 of the high-temperature heat storage tank 5.

[0086] During the period of flat electricity prices, the steam production system of the present application can be in the third operation mode. Fig. 9 The state diagram of the steam production system of the present application in the third operation mode is disclosed. Fig. 9 As shown, in the steam production system of the present application, the first valve 81 and the second valve 82 are opened, the third valve 83 is closed, and the electric heat pump unit 4 partially operates, wherein the low-temperature heat storage tank 1 does not release heat, and the high-temperature heat storage tank 5 does not store heat.

[0087] The heat source water directly enters the heat exchange unit 22 through the heat source water supply pipeline 71. The heat source water after heat exchange and cooling is connected to the second interface 12 connected to the low-temperature heat storage tank 1 and the evaporator outlet of the electric heat pump unit 4. The water flow direction at the first interface 11 of the low-temperature heat storage tank 1 is related to the specific design of the scheme, and the water flow direction at the second interface 12 of the low-temperature heat storage tank 1 is also corresponding to it. In addition, the water at the evaporator outlet of the electric heat pump unit 4 directly enters the heat source return water pipeline 72. The heat exchange unit 22 and the electric heat pump unit 4 heat the flash return water of the first flash unit 21 and the flash return water of the second flash unit 3 respectively, and the required steam is produced by flash evaporation and enters the steam delivery pipeline 73.

[0088] The steam production system of the present application realizes the cascade comprehensive utilization of hot water of different grades, and at the same time, it also absorbs the excess electricity in the low electricity price period and reduces the electricity consumption in the high electricity price period and the normal electricity price period. The cascade comprehensive utilization method of hot water of different grades is that the high-grade hot water is directly flashed to produce steam, and the low-grade hot water is upgraded by the electric heat pump to make steam and store heat. At the same time, in different electricity price periods, in order to achieve the peak shaving and valley filling function, there are different operation strategies: in the high electricity price period, the high-grade hot water is flashed and cooled, and then enters the low-temperature heat storage tank 1 for storage, while the high-temperature heat storage tank 5 directly flashes and produces steam; in the low electricity price period, the high-grade hot water is flashed and cooled, and then enters the evaporator in the electric heat pump unit 4 together with the water stored in the low-temperature heat storage tank 1, and its heat is recovered for heating the water stored in the high-temperature heat storage tank 5 and producing steam.

[0089] The steam production system of the present application not only realizes the peak shaving and valley filling function and assists in the regulation of the power system, but also further reduces the operating cost, improves the economy and broadens the application scenarios of water transmission and steam production.

[0090] The present application also provides a control method for a steam production system. The steam production system includes a low-temperature heat storage tank 1, a first component 2 having a first flash unit 21, a second flash unit 3, an electric heat pump unit 4 and a high-temperature heat storage tank 5. The control method for the steam production system of the present application may include steps S1 to S2.

[0091] In step S1, combined with reference Figure 7 As shown, during the peak electricity price period, the steam production system can be controlled to be in the first operation mode, wherein, in the first operation mode, the electric heat pump unit 4 is controlled to stop running, the low-temperature heat storage tank 1 and the high-temperature heat storage tank 5 are disconnected from the electric heat pump unit 4, and the steam flashed by the first flash unit 21 and the high-temperature water stored in the high-temperature heat storage tank 5 flashed by the second flash unit 3 enter the steam delivery pipeline 73 together.

[0092] In step S2, combined with reference Figure 8 As shown, during the valley electricity price period, the steam production system can be controlled to be in the second operation mode, wherein, in the second operation mode, the electric heat pump unit 4 is controlled to operate normally, the low-temperature heat storage tank 1 and the high-temperature heat storage tank 5 are both connected to the electric heat pump unit 4, the low-temperature water cooled by the first component 2 is mixed with the outlet water of the low-temperature heat storage tank 1 and enters the electric heat pump unit 4, a part of the hot water heated by the electric heat pump unit 4 enters the second flash unit 3, and the other part of the hot water is stored in the high-temperature heat storage tank 5, and the steam flashed by the second flash unit 3 and the steam flashed by the first flash unit 21 enter the steam delivery pipeline 73 together.

[0093] In some embodiments, the control method of the steam production system of the present application may further include step S3.

[0094] In step S3, combined with reference Fig. 9 As shown, during the period of flat electricity price, the steam production system can be controlled to be in the third operation mode, wherein, in the third operation mode, the electric heat pump unit 4 is controlled to partially operate, the electric heat pump unit 4 is disconnected from the high-temperature heat storage tank 5, the low-temperature water cooled by the first component 2 enters the electric heat pump unit 4, the hot water heated by the electric heat pump unit 4 enters the second flash unit 3, the steam flashed by the second flash unit 3 and the steam flashed by the first flash unit 21 enter the steam delivery pipeline 73 together, wherein the low-temperature heat storage tank 1 does not release heat, and the high-temperature heat storage tank 5 does not store heat.

[0095] The steam production system may further include a compressor unit 6. In some embodiments, the control method of the steam production system of the present application may further include step S4.

[0096] In step S4 , the steam flashed by any one of the first flash unit 21 and the second flash unit 3 may be further compressed by the compressor unit 6 and enter the steam delivery pipeline 73 .

[0097] The first component 2 may further include a heat exchange unit 22. Therefore, in some embodiments, the control method of the steam production system of the present application may further include step S5.

[0098] In step S5, before the hot water is flashed in the first flash unit 21 in the first component 2, the hot water is input into the heat exchange unit 22 in the first component 2 to exchange heat with the flash return water after the flash in the first flash unit 21. The hot water heated by the heat exchange unit 22 enters the first flash unit 21 for flashing.

[0099] The low-temperature water cooled by the first component 2 includes: the low-temperature water cooled by heat exchange in the heat exchange unit 22 .

[0100] In the case where the first component 2 has the heat exchange unit 22 , the low-temperature water cooled by the first component 2 includes: the low-temperature water cooled by heat exchange by the heat exchange unit 22 .

[0101] In the case where the first component 2 does not have the heat exchange unit 22 , the low-temperature water cooled by the first component 2 includes: flash return water after flash evaporation by the first flash evaporation unit 21 .

[0102] The control method of the steam production system of one or more embodiments of the present application adopts different methods to achieve cascade utilization according to different grades of heat source water, thereby making full use of heat and improving overall efficiency.

[0103] The control method of the steam production system of one or more embodiments of the present application utilizes a high-temperature heat storage tank 5, a low-temperature heat storage tank 1 and an electric heat pump unit 4 to transfer electricity from periods of low electricity prices to periods of high electricity prices, thereby facilitating the absorption of renewable energy and the regulation of the power grid.

[0104] The control method of the steam production system of one or more embodiments of the present application improves the economy of the steam production system by adjusting the operation strategy in different time periods, changing the equipment operation mode in different electricity price periods, using more electricity in low electricity price periods, and reducing electricity in high electricity price periods.

[0105] The steam production system and control method thereof provided in the embodiment of the present application are introduced in detail above. Specific examples are used herein to illustrate the steam production system and control method thereof in the embodiment of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A steam production system, characterized in that: It includes a low-temperature heat storage tank, a high-temperature heat storage tank, a first component having a first flash evaporation unit, a second flash evaporation unit and an electric heat pump unit, wherein the first component has a water inlet and a water outlet, wherein: The water inlet and the water outlet of the first flash unit are respectively connected to the water inlet and the water outlet of the first component, and the water inlet of the first component is used to connect to the heat source water supply pipeline; The first interface of the low-temperature heat storage tank is connected to the water outlet of the first component and the evaporator inlet of the electric heat pump unit, and the second interface of the low-temperature heat storage tank is connected to the evaporator outlet of the electric heat pump unit and is used to connect to the heat source return water pipeline; The first interface of the high-temperature heat storage tank is connected to the condenser outlet of the electric heat pump unit and the water inlet of the second flash unit, and the second interface of the high-temperature heat storage tank is connected to the condenser inlet of the electric heat pump unit and the water outlet of the second flash unit; The steam outlet of the first flash unit and the steam outlet of the second flash unit are both used to be connected to a steam delivery pipeline.

2. The steam production system according to claim 1, characterized in that: The first component further includes a heat exchange unit, and the water inlet and the water outlet of the first flash unit are respectively connected to the water inlet and the water outlet of the first component through the heat exchange unit, wherein: The first interface and the second interface of the heat exchange unit are respectively connected to the water inlet and the water outlet of the first component, and the third interface and the fourth interface of the heat exchange unit are respectively connected to the water inlet and the water outlet of the first flash unit.

3. The steam production system according to claim 1, characterized in that: Also included is a compressor unit, wherein The steam inlet of the compressor unit is connected to the steam outlet of any one of the first flash unit and the second flash unit, and the steam outlet of the compressor unit is used to be connected to the steam delivery pipeline.

4. The steam production system according to claim 3, characterized in that: Any one of the first flash unit and the second flash unit comprises a multi-stage flash evaporator, and the multi-stage flash evaporators are sequentially connected in series, wherein the water inlet of the first-stage flash evaporator and the water outlet of the last-stage flash evaporator serve as the water inlet and water outlet of the flash unit respectively, and the water outlet and water inlet of the two adjacent flash evaporators are connected; The compressor unit comprises a multi-stage compressor, which is connected in series in sequence, wherein the steam outlet of each stage of the flash evaporator is respectively connected to the steam inlet of the corresponding first stage of the compressor, and the steam outlet and steam inlet of two adjacent stages of the compressor are connected.

5. The steam production system according to claim 1, characterized in that: The electric heat pump unit comprises a multi-stage electric heat pump, and the multi-stage electric heat pumps are connected in series in sequence, wherein: The first interface and the second interface of the low-temperature heat storage tank are respectively connected to the evaporator inlet of the first-stage electric heat pump and the evaporator outlet of the last-stage electric heat pump, and the evaporator inlet and evaporator outlet of the electric heat pumps of two adjacent stages are connected; The first interface and the second interface of the high-temperature heat storage tank are respectively connected to the condenser outlet of the first-stage electric heat pump and the condenser inlet of the last-stage electric heat pump, and the condenser inlet and condenser outlet of the two adjacent stages of the electric heat pump are connected.

6. The steam production system according to any one of claims 1 to 5, characterized in that: A first valve is provided in the connecting pipeline of the evaporator outlet of the electric heat pump unit; a second valve is provided in the connecting pipeline of the condenser inlet of the electric heat pump unit; and a third valve is provided in the pipeline at at least one of the first interface and the second interface of the high-temperature heat storage tank.

7. The steam production system according to claim 6, characterized in that: The steam production system has at least one operation mode among a first operation mode, a second operation mode and a third operation mode, wherein: In the first operation mode, the first valve and the second valve are closed, the third valve is opened, the electric heat pump unit stops running, and the low-temperature heat storage tank and the high-temperature heat storage tank are disconnected from the electric heat pump unit; In the second operation mode, the first valve, the second valve and the third valve are all opened, and the electric heat pump unit operates normally, wherein the low-temperature heat storage tank releases heat and the high-temperature heat storage tank stores heat; In the third operation mode, the first valve and the second valve are opened, the third valve is closed, and the electric heat pump unit partially operates, wherein the low-temperature heat storage tank does not release heat and the high-temperature heat storage tank does not store heat.

8. The steam production system according to claim 7, characterized in that: During the peak electricity price period, the steam production system is in the first operation mode; during the valley electricity price period, the steam production system is in the second operation mode; during the flat electricity price period, the steam production system is in the third operation mode.

9. A control method for a steam production system, the steam production system comprising a low-temperature heat storage tank, a high-temperature heat storage tank, a first component having a first flash unit, a second flash unit and an electric heat pump unit, characterized in that: The control method comprises: During the peak electricity price period, the steam production system is controlled to be in a first operation mode, wherein in the first operation mode, the electric heat pump unit is controlled to stop operating, the low-temperature heat storage tank and the high-temperature heat storage tank are both disconnected from the electric heat pump unit, and the steam flashed by the first flash unit and the high-temperature water stored in the high-temperature heat storage tank flashed by the second flash unit enter the steam delivery pipeline together; During the valley electricity price period, the steam production system is controlled to be in the second operation mode, wherein, in the second operation mode, the electric heat pump unit is controlled to operate normally, the low-temperature heat storage tank and the high-temperature heat storage tank are both connected to the electric heat pump unit, the low-temperature water cooled by the first component is mixed with the outlet water of the low-temperature heat storage tank and enters the electric heat pump unit, a part of the hot water heated by the electric heat pump unit enters the second flash unit, and another part of the hot water is stored in the high-temperature heat storage tank, and the steam flashed by the second flash unit and the steam flashed by the first flash unit enter the steam delivery pipeline together.

10. The control method according to claim 9, characterized in that: The control method further comprises: During the flat electricity price period, the steam production system is controlled to be in a third operation mode, wherein in the third operation mode, the electric heat pump unit is controlled to partially operate, the electric heat pump unit is disconnected from the high-temperature heat storage tank, the low-temperature water cooled by the first component enters the electric heat pump unit, the hot water heated by the electric heat pump unit enters the second flash unit, and the hot water is flashed by the second flash unit. The steam after steaming and the steam after flashing in the first flash unit enter the steam delivery pipeline together, Wherein, the low-temperature heat storage tank does not release heat, and the high-temperature heat storage tank does not store heat.

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