Waste heat recovery poly-generation system and operation method

Abstract

The invention discloses a waste heat recovery poly-generation system and an operation method. The system comprises a waste heat utilization subsystem, a waste heat exchange subsystem and a heat storage subsystem. The waste heat utilization subsystem at least comprises a power generation unit, a refrigeration unit and a heat supply unit; the waste heat exchange subsystem comprises a waste heat exchanger and a switching valve group, the waste heat exchanger is used for collecting waste heat generated in the industrial process, and the switching valve group is used for enabling all units in the waste heat utilization subsystem and the waste heat exchanger to be switched on and off according to the system operation working condition; the heat storage subsystem is used for supplying heat to the waste heat utilization subsystem through the switching valve group independently or in combination with the waste heat exchanger when the heat supply of the waste heat exchanger is insufficient; when the heat supply of the waste heat exchanger is excessive, the redundant heat energy of the waste heat exchanger is collected and stored. The waste heat utilization subsystem, the waste heat exchange subsystem and the heat storage subsystem are integrated, the diversified energy requirements can be met, full utilization of waste heat in the full time scale is achieved, and the waste heat utilization rate and the system operation flexibility are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial waste heat utilization, and in particular relates to a waste heat recovery polygeneration system and an operation method. Background Art

[0002] my country is a country with large energy consumption. Stable and sufficient waste heat will be generated during the industrial production process, which has huge room for utilization and recycling potential. How to improve energy utilization and cleanliness of energy supply is a new research direction in the field of waste heat utilization.

[0003] In the existing technology, waste heat resources are mainly converted in a single form, and waste heat utilization technology is only used when there is a corresponding demand. The energy utilization rate is low and it cannot meet the diverse energy needs of users. In addition, the waste heat is determined by the industrial production process. In the waste heat utilization technology, the flexibility of waste heat regulation is low, resulting in supply and demand mismatch or energy waste. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a waste heat recovery polygeneration system and an operation method. By setting a switching valve group and a heat storage subsystem, waste heat is converted into cold, heat and electricity supply to meet diversified energy needs, achieve full utilization of waste heat on a full time scale, and improve waste heat utilization rate and system operation flexibility.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a waste heat recovery multi-generation system, comprising a waste heat utilization subsystem, a waste heat exchange subsystem and a heat storage subsystem; the waste heat utilization subsystem comprises at least a power generation unit, a refrigeration unit and a heating unit; the waste heat exchange subsystem comprises a waste heat exchanger and a switching valve group, the waste heat exchanger is used to collect waste heat generated in an industrial process, and the switching valve group is used to make the waste heat exchanger only supply heat to the power generation unit, only supply heat to the refrigeration unit, only supply heat to the heating unit, simultaneously supply heat to the refrigeration unit and the power generation unit, or simultaneously supply heat to the heating unit and the power generation unit according to the system operating conditions; the heat storage subsystem is used to heat the waste heat utilization subsystem independently or in combination with the waste heat exchanger through the switching valve group when the waste heat exchanger is insufficient in heating; when the waste heat exchanger is excessive in heating, the waste heat exchanger is connected to collect and store excess thermal energy.

[0006] In combination with the first aspect, further, the switching valve group includes valve one, valve two, valve three, valve four, valve five, valve six, valve seven and valve eight, one port of the waste heat exchanger is connected to the thermal oil supply pipeline through the waste heat circulation pump, and the other port is connected to the thermal oil return pipeline; after the thermal oil supply pipeline is connected in series with valve one, it is connected to the thermal oil input end of the heating unit through valve seven, and is connected to the thermal oil input end of the refrigeration unit through valve eight; after the thermal oil return pipeline is connected in series with valve three, it is connected to the thermal oil output end of the heating unit through valve five, and is connected to the thermal oil output end of the refrigeration unit through valve six; the thermal oil input end of the power generation unit is connected to the thermal oil supply pipeline through valve two, and the thermal oil output end of the power generation unit is connected to the thermal oil return pipeline through valve four.

[0007] In combination with the first aspect, further, the power generation unit includes an evaporator, an expander, a regenerator, a condenser, a working fluid booster pump, a cooling circulation pump and a cooling tower; the waste heat exchanger is connected to the evaporator through the switching valve group to provide thermal energy for the power generation unit; cooling water flows out of the cooling tower and provides a cold source for the condenser through the cooling circulation pump; when the power generation unit is working, the low-temperature and low-pressure liquid working fluid is pressurized by the working fluid booster pump and converted into a low-temperature and high-pressure liquid working fluid, and the low-temperature and high-pressure liquid working fluid is converted into a high-temperature and high-pressure gaseous working fluid after heat exchange through the regenerator and the evaporator in turn, and the high-temperature and high-pressure gaseous working fluid drives the generator to do work through the expander, enters the regenerator for heat exchange, and is converted back into a low-temperature and low-pressure liquid working fluid after cooling by the condenser, thereby realizing the power generation cycle.

[0008] In combination with the first aspect, further, the refrigeration unit includes a refrigeration unit and a cooling circulation pump 2; the waste heat exchanger is connected to the refrigeration unit through the switching valve group to provide thermal energy for the refrigeration unit; the cooling circulation pump 2 is connected to the cooling tower, and cooling water flows out of the cooling tower to provide a cold source for the refrigeration unit through the cooling circulation pump 2; when the refrigeration unit is working, high-temperature heat transfer oil flows out of the waste heat exchanger and enters the refrigeration unit through the switching valve group, and the working fluid in the refrigeration unit exchanges energy to drive the refrigerator to cool; the low-temperature heat transfer oil generated after heat release flows back to the waste heat exchanger through the switching valve group to be heated, and the cooling water absorbs heat and flows back to the cooling tower for cooling, thereby achieving continuous cooling.

[0009] In combination with the first aspect, further, the heating unit includes a heat network heat exchanger, which is connected to the waste heat exchanger through the switching valve group; when the heating unit is working, high-temperature heat transfer oil flows out of the waste heat exchanger, enters the heat network heat exchanger through the switching valve group to provide heat energy, and the low-temperature heat transfer oil generated after heat release flows back to the waste heat exchanger through the switching valve group to be heated, thereby achieving continuous heating.

[0010] In combination with the first aspect, further, the heat storage subsystem includes a heat storage tank, a heat storage circulation pump 1, a valve 9, a valve 10 and a valve 12, and the valve 10 is connected in parallel to the two ends of the heat storage circulation pump 1; when the waste heat exchanger is insufficient in heat supply, the valve 10 is closed, and the heat storage tank pumps out the high-temperature heat transfer oil through the heat storage circulation pump 1 and the valve 9, and supplies heat to the waste heat utilization subsystem through the switching valve group, and the low-temperature heat transfer oil generated after heat release flows back to the heat storage tank through the valve 12; when the waste heat exchanger is excessive in heat supply, the heat storage circulation pump 1 is closed, and the low-temperature heat transfer oil in the heat storage tank flows into the waste heat exchanger through the valve 12 to be heated, and the high-temperature heat transfer oil generated after heat absorption flows back to the heat storage tank through the valve 9 and the valve 10.

[0011] In combination with the first aspect, further, the heat storage subsystem also includes a solar collector for converting solar energy into thermal energy and storing it in the heat storage tank.

[0012] In combination with the first aspect, further, the connecting pipeline between the solar collector and the heat storage tank is provided with a heat storage circulation pump 2 for driving the heat transfer oil in the connecting pipeline to circulate and store heat, and a valve 11 for controlling the opening and closing of the connecting pipeline.

[0013] In a second aspect, the present invention further provides an operation method of a waste heat recovery cogeneration system, comprising: in response to operating only the power generation condition, controlling the switching valve group so that the waste heat exchanger is connected only to the power generation unit, at which time the refrigeration unit and the heating unit are shut down; and / or, in response to operating only the refrigeration condition, controlling the switching valve group so that the waste heat exchanger is connected only to the refrigeration unit, at which time the power generation unit and the heating unit are shut down; and / or, in response to operating only the heating condition, controlling the switching valve group so that the waste heat exchanger is connected only to the heating unit, at which time the power generation unit and the refrigeration unit are shut down; and / or, in response to operating both refrigeration and power generation, In response to the operating condition of simultaneous operation of heating and power generation, the switching valve group is controlled to connect the waste heat exchanger to the heating unit and the power generation unit at the same time, and the refrigeration unit is shut down; and / or, in response to insufficient heating of the waste heat exchanger, the switching valve group is controlled to enable the heat storage subsystem to heat the waste heat utilization subsystem independently or in conjunction with the waste heat exchanger; and / or, in response to excess heating of the waste heat exchanger, the heat storage subsystem is controlled to connect to the waste heat exchanger to collect and store excess thermal energy.

[0014] In combination with the second aspect, further, controlling the switching valve group so that the waste heat exchanger is connected only to the power generation unit includes: opening the valve two and the valve four, and closing the valve one, valve three, valve five, valve six, valve seven, and valve eight; controlling the switching valve group so that the waste heat exchanger is connected only to the refrigeration unit includes: opening the valve one, valve three, valve six, and valve eight, and closing the valve two, valve four, valve five, and valve seven; controlling the switching valve group so that the waste heat exchanger is connected only to the heating unit includes: opening the valve one , valve three, valve five, valve seven, and close valve two, valve four, valve six, and valve eight; the controlling of the switching valve group to connect the waste heat exchanger to the refrigeration unit and the power generation unit at the same time includes: opening valve one, valve two, valve three, valve four, valve six, and valve eight, and closing valve five and valve seven; the controlling of the switching valve group to connect the waste heat exchanger to the heating unit and the power generation unit at the same time includes: opening valve one, valve two, valve three, valve four, valve five, and valve seven, and closing valve six and valve eight.

[0015] Compared with the prior art, the present invention can at least achieve the following beneficial effects: 1. The waste heat recovery polygeneration system provided by the present invention connects the waste heat exchange subsystem and the waste heat utilization subsystem by setting a switching valve group, and adjusts the on-off of the switching valve group according to the system operating conditions, so that the waste heat exchanger can heat different waste heat utilization units, convert waste heat into cold, heat and electricity supply, meet diversified energy needs, and realize full utilization of waste heat in all time scales; 2. The waste heat recovery polygeneration system provided by the present invention provides a heat storage subsystem to provide heat for the waste heat utilization subsystem when the waste heat heat exchange subsystem does not provide sufficient heat, and collects and stores excess heat energy when the waste heat heat exchange subsystem provides excess heat, thereby improving the waste heat utilization rate and system operation flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of a waste heat recovery polygeneration system provided by an embodiment of the present invention.

[0018] In the figure: 100-waste heat utilization subsystem; 200-waste heat exchange subsystem; 300-heat storage subsystem; 101-power generation unit; 102-refrigeration unit; 103-heat supply unit; 1-waste heat exchanger; 2-waste heat circulation pump; 3-valve one; 4-valve two; 5-valve three; 6-valve four; 7-valve five; 8-valve six; 9-valve seven; 10-valve eight; 11-valve nine; 12-heat storage circulation pump one; 13-valve ten; 14-heat storage tank; 15-valve eleven; 16-solar collector; 17-heat storage circulation pump two; 18-valve twelve; 19-evaporator; 20-expander; 21-regenerator; 22-condenser; 23-working fluid booster pump; 24-cooling circulation pump one; 25-cooling tower; 26-heat network heat exchanger; 27-refrigeration unit; 28-cooling circulation pump two. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0020] Embodiment 1:

[0021] This embodiment provides a waste heat recovery polygeneration system. Figure 1, including a waste heat utilization subsystem 100, a waste heat heat exchange subsystem 200 and a heat storage subsystem 300; the waste heat utilization subsystem 100 includes multiple waste heat utilization units, such as a power generation unit 101, a refrigeration unit 102 and a heating unit 103, which are used to convert the waste heat in the waste heat exchange subsystem 200 into electricity, cold and heat required by the user's production and life, and can also include other waste heat utilization units that convert waste heat into energy for equipment or users. Specifically, the power generation unit 101 is used to meet the user's electricity demand on a full time scale, the refrigeration unit 102 is used to meet the user's cooling demand in the non-heating season, and the heating unit 103 is used to meet the user's heating demand in the heating season.

[0022] It should be noted that the power generation unit 101 can select an organic Rankine cycle power generation system, which has a simple structure, convenient manufacturing, strong adaptability, and is environmentally friendly, and the organic cycle working fluid uses R245fa; the refrigeration unit 102 can select an absorption refrigeration system, which has low energy consumption, low noise, stable operation, and easy installation and maintenance; the heating unit 103 can select a heat network heating system, which can provide a stable high-quality heat source, save energy, reduce pollution, and effectively use space. In actual industrial applications, the types of power generation units 101, refrigeration units 102, and heating units 103 are not limited to this, and other systems that can achieve the same conversion function can also be selected. For example, the power generation unit 101 can also select other low-temperature power generation technologies such as the Kalina cycle.

[0023] The waste heat exchange subsystem 200 includes a waste heat exchanger 1, which is used to collect waste heat generated in the industrial process and provide heat for the waste heat utilization subsystem 100; it also includes a switching valve group connecting the three subsystems, and the switching valve group is used to make the waste heat exchanger 1 only provide heat to the power generation unit 101, only provide heat to the refrigeration unit 102, only provide heat to the heating unit 103, provide heat to the refrigeration unit 102 and the power generation unit 101 at the same time, or provide heat to the heating unit 103 and the power generation unit 101 at the same time according to the five operating conditions of the system.

[0024] When the waste heat exchanger 1 does not provide sufficient heat, the heat storage subsystem 300 can release heat by switching the valve group to provide heat for the waste heat utilization subsystem 100, or it can be combined with the waste heat exchanger 1 to provide heat for the waste heat utilization subsystem 100 to meet the system load demand; when the waste heat exchanger 1 provides excess heat, it can also be connected to the waste heat exchanger 1 to collect and store excess thermal energy, adjust the system energy, and achieve peak shaving and valley filling.

[0025] This embodiment provides a heat storage subsystem to provide heat to the waste heat utilization subsystem when the waste heat exchange subsystem is insufficiently supplied with heat, and to collect and store excess heat energy when the waste heat exchange subsystem is excessively supplied with heat, thereby improving waste heat utilization and system operation flexibility.

[0026] In this embodiment, if Figure 1As shown, the switching valve group includes valve 1 3, valve 2 4, valve 3 5, valve 4 6, valve 5 7, valve 6 8, valve 7 9 and valve 8 10; one port of the waste heat exchanger 1 is connected to the heat oil supply pipeline through the waste heat circulation pump 2, and the high-temperature heat oil flows out of the waste heat exchanger 1, and provides heat energy for the waste heat utilization subsystem 100 through the waste heat circulation pump 2; the other port is connected to the heat oil return pipeline, and the low-temperature heat oil generated after the high-temperature heat oil absorbs heat through the waste heat utilization subsystem 100 flows back to the waste heat exchanger 1 to be heated again.

[0027] Furthermore, after the heat transfer oil supply pipeline is connected in series with valve one 3, it is split into two branches for high-temperature heat transfer oil circulation, connected to the heat transfer oil input end of the heating unit 103 through valve seven 9, and the heat transfer oil output end of the heating unit 103 is connected to valve five 7; connected to the heat transfer oil input end of the refrigeration unit 102 through valve eight 10, and the heat transfer oil output end of the refrigeration unit 102 is connected to valve six 8; the low-temperature heat transfer oil flows through valve five 7 or valve six 8 and then flows back to the waste heat exchanger 1 through valve three 5 connected in series on the heat transfer oil return pipeline. The branch of the heat transfer oil supply pipeline connected in parallel with valve one 3 is connected to the heat transfer oil input end of the power generation unit 101 through valve two 4, and the branch of the heat transfer oil return pipeline connected in parallel with valve three 5 is connected to the heat transfer oil output end of the power generation unit 101 through valve four 6.

[0028] In this embodiment, a switching valve group is set to connect the waste heat exchange subsystem and the waste heat utilization subsystem, and the on-off of the switching valve group is adjusted according to the system operating conditions, so that the waste heat exchanger can provide heat for different waste heat utilization units, converting waste heat into cold, heat and electricity supply, meeting diversified energy needs, and realizing full utilization of waste heat on a full time scale.

[0029] Embodiment 2:

[0030] This embodiment provides a waste heat recovery polygeneration system, which is different from the first embodiment in that Figure 1 As shown, the power generation unit 101 includes an evaporator 19, an expander 20, a regenerator 21, a condenser 22, a working fluid booster pump 23, a cooling circulation pump 24 and a cooling tower 25.

[0031] The operation method of the waste heat recovery polygeneration system provided in this embodiment under the condition of only power generation is: control the switching valve group so that the waste heat exchanger 1 in the waste heat exchange subsystem 200 is only connected to the power generation unit 101, that is, open valve two 4 and valve four 6, close valve one 3, valve three 5, valve five 7, valve six 8, valve seven 9, valve eight 10, at this time, the power generation unit 101 is running, and the refrigeration unit 102 and the heating unit 103 are stopped. The high-temperature heat transfer oil in the waste heat exchanger 1 flows into the evaporator 19 through the waste heat circulation pump 2 and valve two 4 to provide heat energy for the power generation unit 101, and the low-temperature heat transfer oil after heat release flows back to the waste heat exchanger 1 through valve four 6 to be heated; the cooling water flows out from the cooling tower 25 after heat release, flows into the condenser 22 through the cooling circulation pump one 24, and provides a cold source for the condenser 22, and the cooling water absorbs heat and flows back to the cooling tower 25 for cooling.

[0032] When the power generation unit 101 is working, the low-temperature, low-pressure saturated liquid working medium first enters the working medium booster pump 23 for pressurization, and after being compressed into a low-temperature, high-pressure liquid working medium, absorbs heat through the regenerator 21, and then further absorbs heat through the evaporator 19 to evaporate into a high-temperature, high-pressure gaseous working medium, and finally enters the expander 20 to expand and do work to drive the generator (not shown in the figure) to generate electricity; after the high-temperature, high-pressure gaseous working medium expands and does work, the temperature and pressure drop at the same time, and then enters the regenerator 21 and condenser 22 to release heat, and after cooling, it is converted back into a low-temperature, low-pressure liquid working medium, and enters the working medium booster pump 23 for pressurization again. The organic working medium circulates in the evaporator 19, the expander 20, the regenerator 21, the condenser 22, and the working medium booster pump 23 for energy conversion, thereby realizing the power generation cycle.

[0033] In some embodiments, Figure 1 As shown, the refrigeration unit 102 includes a refrigeration unit 27 connected to the waste heat exchanger 1 through a switching valve group and a cooling circulation pump 28 connected to the cooling tower 25.

[0034] The operation method of the waste heat recovery polygeneration system provided in this embodiment under the cooling-only working condition is: control the switching valve group so that the waste heat exchanger 1 in the waste heat exchange subsystem 200 is only connected to the refrigeration unit 102, that is, open valve one 3, valve three 5, valve six 8, valve eight 10, and close valve two 4, valve four 6, valve five 7, valve seven 9. At this time, the refrigeration unit 102 is running, and the power generation unit 101 and the heating unit 103 are stopped.

[0035] When the refrigeration unit 102 is working, the high-temperature heat transfer oil in the waste heat exchanger 1 flows into the refrigeration unit 27 through the waste heat circulation pump 2, valve one 3 and valve eight 10 in turn, providing heat energy for the refrigeration unit 102; the cooling water flows out from the cooling tower 25 after releasing heat, and flows into the refrigeration unit 27 through the cooling circulation pump two 28, providing a cold source for the refrigeration unit 102; the working fluid pairs composed of high-efficiency working fluids such as lithium bromide in the refrigeration unit 27 exchange energy under the action of the heat source and the cold source to drive the refrigerator (not marked in the figure) for refrigeration; the low-temperature heat transfer oil after releasing heat flows back to the waste heat exchanger 1 through valve six 8 and valve three 5 in turn to be heated, and the cooling water absorbs heat and flows back to the cooling tower 25 for cooling, thereby achieving continuous refrigeration.

[0036] It should be noted that, in this embodiment, the cooling tower 25 used in the refrigeration unit 102 and the power generation unit 101 has the same function, so the two waste heat utilization units share one cooling tower 25 to save costs; in actual industrial applications, the refrigeration unit 102 may also include a cooling tower 25 to achieve the same function, and the specific needs depend on the refrigeration system selected in actual conditions and the size of the utilized space.

[0037] As an example, Figure 1 As shown, the heating unit 103 includes a heat network heat exchanger 26 connected to the waste heat exchanger 1 through a switching valve group.

[0038] The operation method of the waste heat recovery polygeneration system provided in this embodiment under the heating-only working condition is: control the switching valve group so that the waste heat exchanger 1 in the waste heat exchange subsystem 200 is only connected to the heating unit 103, that is, open valve one 3, valve three 5, valve five 7, valve seven 9, and close valve two 4, valve four 6, valve six 8, valve eight 10. At this time, the heating unit 103 is running, and the power generation unit 101 and the refrigeration unit 102 are stopped.

[0039] When the heating unit 103 is working, the high-temperature heat transfer oil in the waste heat exchanger 1 flows into the heat network heat exchanger 26 through the waste heat circulation pump 2, valve one 3 and valve seven 9 in sequence, providing heat energy for the heating unit 103; the low-temperature heat transfer oil generated after heat release flows back to the waste heat exchanger 1 through valve five 7 and valve three 5 to be heated, thereby realizing continuous heating.

[0040] Embodiment three:

[0041] This embodiment provides a waste heat recovery polygeneration system, which is different from the first embodiment in that Figure 1As shown, the heat storage subsystem 300 includes a heat storage tank 14, a heat storage circulation pump 12, a valve 9 11, a valve 13 and a valve 12 18; the heat storage circulation pump 12, the valve 9 11 and the valve 10 13 are arranged at one end of the heat storage tank 14 and connected to the heat transfer oil supply pipeline, the valve 10 13 is connected in parallel to both ends of the heat storage circulation pump 12 and then connected in series with the valve 9 11; the valve 12 18 is arranged at the other end of the heat storage tank 14 and connected to the heat transfer oil return pipeline.

[0042] The operation method of the waste heat recovery polygeneration system provided in this embodiment when the waste heat exchanger 1 is insufficiently supplied with heat is as follows: control the switching valve group to make the heat storage tank 14 in the heat storage subsystem 300 release heat to supply heat to the waste heat utilization subsystem 100, and open the valve nine 11, the heat storage circulation pump one 12 and the valve twelve 18, and close the valve ten 13. At this time, the high-temperature heat transfer oil in the heat storage tank 14 is connected to the heat transfer oil supply pipeline through the heat storage circulation pump one 12 and the valve nine 11, and flows into the heat transfer oil input end of the waste heat utilization subsystem 100, and the heat supply for different waste heat utilization units is realized by controlling the switching valve group on and off as in the second embodiment; the low-temperature heat transfer oil generated after heat release flows back to the heat storage tank 14 through the valve twelve 18.

[0043] It should be noted that when the waste heat exchanger 1 is insufficient in heat but can still provide heat energy for the waste heat utilization subsystem 100, the heat storage subsystem 300 can cooperate with the waste heat exchanger 1 to provide heat for the waste heat utilization subsystem 100 to meet the system load demand.

[0044] The operation method of the waste heat recovery polygeneration system provided in this embodiment when the waste heat exchanger 1 is in excess heat supply is as follows: the heat storage tank 14 in the heat storage subsystem 300 is controlled to be connected to the waste heat exchanger 1 to collect and store excess heat energy, and the valve nine 11, valve ten 13 and valve twelve 18 need to be opened, and the heat storage circulation pump one 12 is closed. At this time, the low-temperature heat transfer oil in the heat storage tank 14 is connected to the heat transfer oil return pipeline through the valve twelve 18, flows into the waste heat exchanger 1 to be heated, and the high-temperature heat transfer oil generated after absorbing heat flows back to the heat storage tank 14 through the waste heat circulation pump 2, valve nine 11 and valve ten 13, so as to adjust the system energy and realize peak shaving and valley filling.

[0045] As an optional embodiment, in order to increase the heat energy source of the heat storage tank 14 and ensure the stable operation of the system, the heat storage subsystem 300 also includes a solar collector 16, which is used to convert solar energy into heat energy and store it in the heat storage tank 14; in addition, the connection pipeline between the solar collector 16 and the heat storage tank 14 is provided with a heat storage circulation pump 2 17 for driving the heat transfer oil in the connection pipeline to circulate and store heat, and a valve 11 15 for controlling the connection and disconnection of the connection pipeline. When the sun is sufficient, the valve 11 15 and the heat storage circulation pump 2 17 are opened, and the low-temperature heat transfer oil in the heat storage tank 14 flows to the solar collector 16 through the heat storage circulation pump 2 17 to absorb heat to high temperature, and then flows back to the heat storage tank 14 through the valve 11 15; when the sun is insufficient, the valve 11 15 and the heat storage circulation pump 2 17 are closed, and the solar collector 16 stops running.

[0046] This embodiment effectively improves space utilization by converting light energy into heat energy and storing it in a heat storage tank; the heat storage tank improves the flexibility and stability of system operation by regulating the energy in the system, achieves accurate matching of energy supply and demand, and reduces energy waste.

[0047] It should be noted that the heat storage tank 14 can also be replaced by a fluidized bed with phase change heat storage or other equipment with heat storage function; the solar collector 16 adopts a heat pipe vacuum tube solar water heater. In actual industrial applications, whether to set up the solar collector 16 can be planned according to the actual utilization space.

[0048] Embodiment 4:

[0049] This embodiment provides an operation method of a waste heat recovery polygeneration system, including several operation methods of the waste heat recovery polygeneration system as described in Embodiment 2 and Embodiment 3; in addition, it also includes: The operation method of the waste heat recovery polygeneration system under the condition of simultaneous cooling and power generation is: control the switching valve group to make the waste heat exchanger 1 in the waste heat exchange subsystem 200 connect to the refrigeration unit 102 and the power generation unit 101 at the same time, that is, open valve one 3, valve two 4, valve three 5, valve four 6, valve six 8, valve eight 10, and close valve five 7 and valve seven 9. At this time, the refrigeration unit 102 and the power generation unit 101 are in operation, and the heating unit 103 is stopped.

[0050] The operation method of the waste heat recovery polygeneration system under the condition of simultaneous heating and power generation is: control the switching valve group to make the waste heat exchanger 1 in the waste heat exchange subsystem 200 connect to the heating unit 103 and the power generation unit 101 at the same time, that is, open valve one 3, valve two 4, valve three 5, valve four 6, valve five 7, valve seven 9, and close valve six 8 and valve eight 10. At this time, the heating unit 103 and the power generation unit 101 are running, and the refrigeration unit 102 is stopped.

[0051] The waste heat recovery polygeneration system provided in the embodiment of the present invention integrates waste heat heat exchange, power generation, refrigeration, heating and other systems, and realizes the cogeneration of cooling, heating and electricity by using waste heat resources, which can meet the diverse energy needs of users and realize the recycling and utilization of industrial waste heat on a full time scale during the heating season and the non-heating season; at the same time, the heat storage technology is introduced to improve the energy utilization efficiency and the flexibility and stability of the system operation.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0053] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A waste heat recovery polygeneration system, characterized in that: It comprises a waste heat utilization subsystem (100), a waste heat exchange subsystem (200) and a heat storage subsystem (300); The waste heat utilization subsystem (100) comprises at least a power generation unit (101), a refrigeration unit (102) and a heating unit (103); The waste heat exchange subsystem (200) comprises a waste heat exchanger (1) and a switching valve group, wherein the waste heat exchanger (1) is used to collect waste heat generated in an industrial process, and the switching valve group is used to enable the waste heat exchanger (1) to supply heat only to the power generation unit (101), only to the refrigeration unit (102), only to the heating unit (103), to supply heat to both the refrigeration unit (102) and the power generation unit (101), or to both the heating unit (103) and the power generation unit (101) according to system operating conditions; The heat storage subsystem (300) is used to supply heat to the waste heat utilization subsystem (100) independently or in conjunction with the waste heat exchanger (1) through the switching valve group when the waste heat exchanger (1) is insufficiently supplying heat; and to connect to the waste heat exchanger (1) to collect and store excess heat energy when the waste heat exchanger (1) is supplying excess heat.

2. The waste heat recovery polygeneration system according to claim 1, characterized in that: The switching valve group comprises valve 1 (3), valve 2 (4), valve 3 (5), valve 4 (6), valve 5 (7), valve 6 (8), valve 7 (9) and valve 8 (10); one port of the waste heat exchanger (1) is connected to a heat transfer oil supply pipeline via a waste heat circulation pump (2), and the other port is connected to a heat transfer oil return pipeline; After the heat transfer oil supply pipeline is connected in series with the valve one (3), it is connected to the heat transfer oil input end of the heating unit (103) through the valve seven (9), and is connected to the heat transfer oil input end of the refrigeration unit (102) through the valve eight (10); After the heat transfer oil return pipeline is connected in series with the valve three (5), it is connected to the heat transfer oil output end of the heating unit (103) through the valve five (7), and is connected to the heat transfer oil output end of the refrigeration unit (102) through the valve six (8); The heat transfer oil input end of the power generation unit (101) is connected to the heat transfer oil supply pipeline via the second valve (4), and the heat transfer oil output end of the power generation unit (101) is connected to the heat transfer oil return pipeline via the fourth valve (6).

3. The waste heat recovery polygeneration system according to claim 1 or 2, characterized in that: The power generation unit (101) comprises an evaporator (19), an expander (20), a regenerator (21), a condenser (22), a working fluid booster pump (23), a cooling circulation pump (24) and a cooling tower (25); The waste heat exchanger (1) is connected to the evaporator (19) via the switching valve group to provide heat energy for the power generation unit (101); cooling water flows out of the cooling tower (25) and passes through the cooling circulation pump 1 (24) to provide a cold source for the condenser (22); When the power generation unit (101) is in operation, the low-temperature and low-pressure liquid working medium is pressurized by the working medium booster pump (23) and converted into a low-temperature and high-pressure liquid working medium. The low-temperature and high-pressure liquid working medium is successively converted into a high-temperature and high-pressure gaseous working medium through the regenerator (21) and the evaporator (19) for heat exchange. The high-temperature and high-pressure gaseous working medium drives the generator to perform work through the expander (20), enters the regenerator (21) for heat exchange, and is cooled by the condenser (22) and converted back into a low-temperature and low-pressure liquid working medium, thereby realizing a power generation cycle.

4. The waste heat recovery polygeneration system according to claim 3, characterized in that: The refrigeration unit (102) comprises a refrigeration unit (27) and a second cooling circulation pump (28); The waste heat exchanger (1) is connected to the refrigeration unit (27) via the switching valve group to provide heat energy for the refrigeration unit (27); the cooling circulation pump 2 (28) is connected to the cooling tower (25); cooling water flows out of the cooling tower (25) and passes through the cooling circulation pump 2 (28) to provide a cold source for the refrigeration unit (27); When the refrigeration unit (102) is working, high-temperature heat transfer oil flows out of the waste heat exchanger (1) and enters the refrigeration unit (27) through the switching valve group. The working fluid in the refrigeration unit (27) exchanges energy to drive the refrigerator to perform refrigeration. The low-temperature heat transfer oil generated after heat release flows back to the waste heat exchanger (1) through the switching valve group to be heated. The cooling water absorbs heat and flows back to the cooling tower (25) to be cooled, thereby achieving continuous refrigeration.

5. The waste heat recovery polygeneration system according to claim 1 or 2, characterized in that: The heating unit (103) comprises a heat network heat exchanger (26), and the heat network heat exchanger (26) is connected to the waste heat exchanger (1) via the switching valve group; When the heating unit (103) is in operation, high-temperature heat transfer oil flows out of the waste heat exchanger (1) and enters the heat network heat exchanger (26) through the switching valve group to provide heat energy. The low-temperature heat transfer oil generated after heat release then flows back through the switching valve group to the waste heat exchanger (1) to be heated, thereby achieving continuous heat supply.

6. The waste heat recovery polygeneration system according to claim 1, characterized in that: The heat storage subsystem (300) comprises a heat storage tank (14), a heat storage circulation pump 1 (12), a valve 9 (11), a valve 10 (13) and a valve 12 (18), wherein the valve 10 (13) is connected in parallel to both ends of the heat storage circulation pump 1 (12); When the waste heat exchanger (1) does not provide sufficient heat, the valve ten (13) is closed, the heat storage tank (14) pumps out the high-temperature heat transfer oil through the heat storage circulation pump one (12) and the valve nine (11), and supplies heat to the waste heat utilization subsystem (100) through the switching valve group, and the low-temperature heat transfer oil generated after heat release flows back to the heat storage tank (14) through the valve twelve (18); When the waste heat exchanger (1) provides excess heat, the heat storage circulation pump 1 (12) is turned off, and the low-temperature heat transfer oil in the heat storage tank (14) flows into the waste heat exchanger (1) through the valve 12 (18) to be heated, and the high-temperature heat transfer oil generated after absorbing heat flows back to the heat storage tank (14) through the valve 9 (11) and the valve 10 (13).

7. The waste heat recovery polygeneration system according to claim 1 or 6, characterized in that: The heat storage subsystem (300) further comprises a solar collector (16) for converting solar energy into thermal energy and storing the thermal energy in the thermal storage tank (14).

8. The waste heat recovery polygeneration system according to claim 7, characterized in that: The connecting pipeline between the solar collector (16) and the heat storage tank (14) is provided with a heat storage circulation pump 2 (17) for driving the heat transfer oil in the connecting pipeline to circulate and store heat, and a valve 11 (15) for controlling the opening and closing of the connecting pipeline.

9. An operating method of the waste heat recovery polygeneration system according to claim 2, characterized in that: include: In response to the operating condition of only power generation, the switching valve group is controlled so that the waste heat exchanger (1) is connected only to the power generation unit (101), and at this time, the refrigeration unit (102) and the heating unit (103) are stopped; and / or, in response to operating only in a refrigeration condition, controlling the switching valve group so that the waste heat exchanger (1) is connected only to the refrigeration unit (102), and at this time, the power generation unit (101) and the heating unit (103) are stopped; and / or, in response to operating only in a heating condition, controlling the switching valve group so that the waste heat exchanger (1) is connected only to the heating unit (103), and at this time, the power generation unit (101) and the refrigeration unit (102) are stopped; and / or, in response to a condition in which refrigeration and power generation are operated simultaneously, the switching valve group is controlled so that the waste heat exchanger (1) is connected to the refrigeration unit (102) and the power generation unit (101) at the same time, and the heating unit (103) is stopped at this time; and / or, in response to a condition in which heating and power generation are operated simultaneously, the switching valve group is controlled so that the waste heat exchanger (1) is connected to the heating unit (103) and the power generation unit (101) at the same time, and the refrigeration unit (102) is stopped at this time; and / or, in response to insufficient heat supply from the waste heat exchanger (1), controlling the switching valve group so that the heat storage subsystem (300) supplies heat to the waste heat utilization subsystem (100) independently or in conjunction with the waste heat exchanger (1); And / or, in response to the waste heat exchanger (1) providing excess heat, the heat storage subsystem (300) is controlled to connect to the waste heat exchanger (1) to collect and store excess thermal energy.

10. The operating method of the waste heat recovery polygeneration system according to claim 9, characterized in that: The controlling of the switching valve group so that the waste heat exchanger (1) is connected only to the power generation unit (101) comprises: opening the valve two (4) and the valve four (6), and closing the valve one (3), the valve three (5), the valve five (7), the valve six (8), the valve seven (9), and the valve eight (10); The controlling of the switching valve group so that the waste heat exchanger (1) is connected only to the refrigeration unit (102) comprises: opening the valve one (3), the valve three (5), the valve six (8), and the valve eight (10), and closing the valve two (4), the valve four (6), the valve five (7), and the valve seven (9); The controlling of the switching valve group so that the waste heat exchanger (1) is connected only to the heating unit (103) comprises: opening the valve one (3), valve three (5), valve five (7), and valve seven (9), and closing the valve two (4), valve four (6), valve six (8), and valve eight (10); The controlling of the switching valve group so that the waste heat exchanger (1) is connected to the refrigeration unit (102) and the power generation unit (101) at the same time comprises: opening the valve one (3), valve two (4), valve three (5), valve four (6), valve six (8), valve eight (10), and closing the valve five (7) and valve seven (9); The controlling of the switching valve group so that the waste heat exchanger (1) is connected to the heating unit (103) and the power generation unit (101) at the same time comprises: opening the valve one (3), valve two (4), valve three (5), valve four (6), valve five (7), valve seven (9), and closing the valve six (8) and the valve eight (10).

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