A multi-energy coupled combined cooling, heating and power system and method

Abstract

The application discloses a kind of multi-capacity coupling's cold and heat and electricity triple combination system and method, including double-effect lithium bromide absorption heat pump, heat storage device and gas turbine power generation system, wherein, heat storage device is connected with double-effect lithium bromide absorption heat pump and gas turbine power generation system, double-effect lithium bromide absorption heat pump is connected with gas turbine power generation system, the system and method can realize the matching of energy supply and user demand, while reducing energy waste.

Description

Technical Field

[0001] This invention belongs to the field of gas turbine power generation technology, and relates to a multi-energy coupled combined cooling, heating and power system and method. Background Technology

[0002] Combined cooling, heating, and power (CCHP) systems, due to their significant advantage of energy cascade utilization, are multi-generation systems that integrate cooling, heating, and power generation within a single system. These systems are typically located near users, effectively reducing energy loss and saving on transmission and distribution investment costs. Because natural gas has advantages such as high energy efficiency and low combustion pollution, its demand has grown rapidly in recent years, and natural gas is also the fuel consumed by CCHP systems. Natural gas CCHP systems have gradually emerged in recent years. They rely on the combustion of natural gas and air in an internal combustion engine or gas turbine. The high-temperature heat generated drives a generator to supply electricity, the medium-temperature heat can drive a flue gas-hot water chiller for cooling and heating, the low-temperature heat can provide domestic hot water, and the remaining waste heat is directly discharged into the atmosphere. Therefore, the heat is effectively utilized in a cascade manner throughout the process. Although natural gas combined cooling, heating and power (CCHP) systems have attracted much attention due to their high energy efficiency, energy conservation, and environmental benefits, user demand for heat and power is affected by many factors in actual operation, causing the system's energy supply to constantly change. This can lead to a mismatch between the energy supply of the CCHP system and user demand, which will reduce the efficiency of the CCHP system, resulting in energy waste and reduced economic benefits.

[0003] Thermoelectric decoupling involves deep adjustment of the heat-to-power ratio to achieve energy conservation and cost savings. However, combined cooling, heating, and power (CCHP) systems with too small a heat-to-power ratio will not achieve energy conservation. In natural gas CCHP systems, the heat-to-power ratio is relatively fixed, and meeting the dynamic changes in user load will inevitably lead to energy waste and additional economic losses. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-energy coupled combined cooling, heating and power system and method that can match the energy supply with the user's demand while reducing energy waste.

[0005] To achieve the above objectives, the present invention discloses a multi-energy coupled combined cooling, heating and power system comprising a dual-effect lithium bromide absorption heat pump, a thermal storage device, and a gas turbine power generation system, wherein the thermal storage device is connected to the dual-effect lithium bromide absorption heat pump and the gas turbine power generation system, and the dual-effect lithium bromide absorption heat pump is connected to the gas turbine power generation system.

[0006] It also includes a second regulating valve, and the heat storage device includes a fourth heat exchanger, a high-temperature tank, a fifth heat exchanger, a sixth heat exchanger, and a low-temperature tank;

[0007] The gas turbine outlet in the gas turbine power generation system is divided into two paths. One path is connected to the first regulating valve in the gas turbine power generation system, and the other path is connected to the first opening of the second regulating valve. The second opening of the second regulating valve is connected to the tube-side inlet of the fourth heat exchanger. The tube-side outlet of the fourth heat exchanger is connected to the shell side of the sixth heat exchanger. The shell-side outlet of the fourth heat exchanger is connected to the inlet of the high-temperature tank. The outlet of the high-temperature tank is connected to the shell-side inlet of the fifth heat exchanger. The shell-side outlet of the fifth heat exchanger is connected to the inlet of the low-temperature tank. The outlet of the low-temperature tank is connected to the shell-side inlet of the fourth heat exchanger.

[0008] The third opening of the second regulating valve is connected to the high-pressure generator in the double-effect lithium bromide absorption heat pump; the flue gas outlet of the high-pressure generator in the double-effect lithium bromide absorption heat pump is divided into two paths, one of which is connected to the tube-side inlet of the fifth heat exchanger, and the other is connected to the shell side of the second heat exchanger in the double-effect lithium bromide absorption heat pump; the tube-side outlet of the fifth heat exchanger is connected to the flue gas inlet of the high-pressure generator in the double-effect lithium bromide absorption heat pump.

[0009] The multi-energy coupled combined cooling, heating and power (CCHP) method of the present invention includes the following steps:

[0010] During heating, the high-temperature flue gas generated by the gas turbine serves as a high-temperature heat source and enters the high-pressure generator in the double-effect lithium bromide absorption heat pump through the second regulating valve for waste heat recovery. The heat is then generated by the absorber and condenser in the double-effect lithium bromide absorption heat pump to produce hot water for air conditioning under heating conditions.

[0011] The flue gas discharged from the high-pressure generator enters the second heat exchanger to produce low-temperature hot water, which serves as the low-temperature heat source required by the evaporator in the double-effect lithium bromide absorption heat pump. The low-temperature flue gas discharged from the second heat exchanger enters the atmosphere.

[0012] In refrigeration mode, the gas turbine generates high-temperature flue gas, which serves as a high-temperature heat source. The flue gas then enters the high-pressure generator in the double-effect lithium bromide absorption heat pump via the second regulating valve. The high-pressure generator absorbs the heat from the high-temperature flue gas and generates steam. The generated steam is then cooled by the absorber and condenser to produce chilled water for refrigeration mode.

[0013] When the high-temperature flue gas generated by the gas turbine has unused portion in addition to the heat required by the dual-effect lithium bromide absorption heat pump, the high-temperature flue gas generated by the gas turbine is divided into two paths. One path enters the high-pressure generator in the dual-effect lithium bromide absorption heat pump to produce the required air conditioning hot water, and the other path enters the fourth heat exchanger to heat the molten salt in the low-temperature tank.

[0014] The heated molten salt output from the fourth heat exchanger is stored in a high-temperature tank.

[0015] The flue gas discharged from the fourth heat exchanger enters the sixth heat exchanger to produce the domestic hot water needed by the user.

[0016] When the high-temperature flue gas generated by the gas turbine enters the double-effect lithium bromide absorption heat pump and still cannot meet the user's demand for hot water for air conditioning, a higher-temperature flue gas discharged from the high-pressure generator in the double-effect lithium bromide absorption heat pump is led out and sent to the fifth heat exchanger. It is heated into high-temperature flue gas by molten salt in the high-temperature tank, and then sent to the high-pressure generator in the double-effect lithium bromide absorption heat pump to generate hot water for air conditioning under heating conditions, thus meeting the demand for air conditioning water.

[0017] The cooled molten salt output from the fifth heat exchanger is stored in a cryogenic tank.

[0018] The present invention has the following beneficial effects:

[0019] The multi-energy coupled combined cooling, heating, and power (CCHP) system and method described in this invention, in specific operation, includes a dual-effect lithium bromide absorption heat pump, a gas turbine power generation system, and a thermal storage device. Cooling is generated in the dual-effect lithium bromide absorption heat pump, and power is generated through the gas turbine power generation system. Excess heat is stored in the thermal storage device. Based on the principle of energy cascade utilization, this invention recovers heat from the flue gas emitted by the gas turbine. When the heat recovery from the dual-effect lithium bromide absorption heat pump is insufficient, the thermal storage device is used to recover and store additional heat, achieving dynamic matching between the system's energy output and the user's thermal and electrical load demands. This improves the system's operational flexibility, reduces energy waste, and enhances the system's economic efficiency. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the present invention;

[0021] Figure 2 This is a structural diagram of the heat storage device 300 in this invention.

[0022] Among them, 100 is a double-effect lithium bromide absorption heat pump, 200 is a gas turbine power generation system, 300 is a heat storage device, g is a high-pressure generator, h is the first heat exchanger, i is the second heat exchanger, j is the third heat exchanger, k is the first booster pump, l is the absorber, m is the third regulating valve, n is the low-temperature generator, o is the evaporator, p is the fourth regulating valve, q is the condenser, r is the fifth regulating valve, a is the compressor, b is the combustion chamber, c is the gas turbine, d is the generator, e is the first regulating valve, f is the second regulating valve, s is the fourth heat exchanger, t is the high-temperature tank, u is the fifth heat exchanger, w is the sixth heat exchanger, and v is the low-temperature tank. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0024] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0025] It should be noted that existing combined cooling, heating, and power (CCHP) systems consist of power generation equipment and waste heat recovery equipment. In this invention, the power generation equipment is a gas turbine power generation system 200, and the waste heat recovery equipment is a double-effect lithium bromide absorption heat pump 100. Together, they constitute a typical CCHP system. However, the heat and electricity production of this system is relatively fixed, resulting in a essentially fixed heat-to-power ratio with a very small adjustable range. Meanwhile, user demands for heat and electricity loads change accordingly due to seasonal variations, diurnal variations, and other factors. Therefore, a system with a relatively fixed heat-to-power ratio cannot flexibly meet the dynamic changes in user demand for heat and electricity. This leads to a mismatch between the energy provided by the system and user needs, resulting in energy waste, decreased system thermal performance, and reduced economic efficiency. To meet the dynamic matching of the system's energy output with user heat and electricity load demands, a combined cooling, heating, and power (CCHP) system coupled with a thermal storage device 300 is required to improve the system's operational flexibility.

[0026] For details, please refer to Figure 1 and Figure 2The multi-energy coupled combined cooling, heating, and power (CCHP) system of the present invention includes a dual-effect lithium bromide absorption heat pump 100, a heat storage device 300, and a gas turbine power generation system 200. The heat storage device 300 includes a fourth heat exchanger s, a high-temperature tank t, a fifth heat exchanger u, a sixth heat exchanger w, and a low-temperature tank v. The dual-effect lithium bromide absorption heat pump 100 includes a high-pressure generator g, a first heat exchanger h, a second heat exchanger i, a third heat exchanger j, a first booster pump k, an absorber l, a third regulating valve m, a low-temperature generator n, an evaporator o, a fourth regulating valve p, a condenser q, and a fifth regulating valve r. The gas turbine power generation system 200 includes a compressor a, a combustion chamber b, a gas turbine c, a generator d, a first regulating valve e, and a second regulating valve f.

[0027] The outlet of the gas turbine c in the gas turbine power generation system 200 is divided into two paths. One path is connected to the first regulating valve e in the gas turbine power generation system 200, and the other path is connected to the first opening of the second regulating valve f. The second opening of the second regulating valve f is connected to the tube-side inlet of the fourth heat exchanger s. The tube-side outlet of the fourth heat exchanger s is connected to the shell side of the sixth heat exchanger w. The shell-side outlet of the fourth heat exchanger s is connected to the inlet of the high-temperature tank t. The outlet of the high-temperature tank t is connected to the shell-side inlet of the fifth heat exchanger u. The shell-side outlet of the fifth heat exchanger u is connected to the inlet of the low-temperature tank v. The outlet of the low-temperature tank v is connected to the shell-side inlet of the fourth heat exchanger s.

[0028] The third opening of the second regulating valve f is connected to the high-pressure generator g in the double-effect lithium bromide absorption heat pump 100; the flue gas outlet of the high-pressure generator g in the double-effect lithium bromide absorption heat pump 100 is divided into two paths, one of which is connected to the tube-side inlet of the fifth heat exchanger u, and the other is connected to the shell side of the second heat exchanger i in the double-effect lithium bromide absorption heat pump 100; the tube-side outlet of the fifth heat exchanger u is connected to the flue gas inlet of the high-pressure generator g in the double-effect lithium bromide absorption heat pump 100.

[0029] The specific working process of this invention is as follows:

[0030] Natural gas is mixed with air and burned to drive a gas turbine (c) to generate electricity, while also producing high-temperature flue gas.

[0031] During heating, the high-temperature flue gas generated by the gas turbine c serves as a high-temperature heat source and enters the high-pressure generator g in the double-effect lithium bromide absorption heat pump 100 via the second regulating valve f for waste heat recovery. The heat is then used to generate hot water for air conditioning under heating conditions through the absorber l and condenser q in the double-effect lithium bromide absorption heat pump 100.

[0032] The flue gas discharged from the high-pressure generator g enters the second heat exchanger i to produce low-temperature hot water, which serves as the low-temperature heat source required by the evaporator o in the double-effect lithium bromide absorption heat pump 100, thus completing a cycle of low-temperature hot water. The low-temperature flue gas discharged from the second heat exchanger i enters the atmosphere.

[0033] In refrigeration mode, the gas turbine c generates high-temperature flue gas, which serves as a high-temperature heat source. The flue gas then enters the high-pressure generator g inside the double-effect lithium bromide absorption heat pump 100 via the second regulating valve f. The high-pressure generator g absorbs the heat from the high-temperature flue gas and generates steam. The generated steam is then cooled by the absorber l and the condenser q to produce chilled water for refrigeration mode.

[0034] When the high-temperature flue gas generated by the gas turbine c has unused portion after meeting the heating requirements of the dual-effect lithium bromide absorption heat pump 100, the high-temperature flue gas generated by the gas turbine c is divided into two paths. One path enters the high-pressure generator g inside the dual-effect lithium bromide absorption heat pump 100 to produce the required air conditioning hot water. The other path enters the fourth heat exchanger s to heat the molten salt in the low-temperature tank v. The flue gas discharged from the fourth heat exchanger s enters the sixth heat exchanger w to produce the domestic hot water required by the user. The heated molten salt output from the fourth heat exchanger s enters the high-temperature tank t for storage.

[0035] When the high-temperature flue gas generated by the gas turbine c enters the double-effect lithium bromide absorption heat pump 100 and still cannot meet the user's demand for hot water for air conditioning, a higher-temperature flue gas discharged from the high-pressure generator g in the double-effect lithium bromide absorption heat pump 100 is led out and sent to the fifth heat exchanger u. It is heated to high-temperature flue gas by molten salt in the high-temperature tank t, and then sent to the high-pressure generator g in the double-effect lithium bromide absorption heat pump 100 to generate hot water for air conditioning under heating conditions, thereby meeting the demand for air conditioning water. The molten salt after heat exchange and cooling is sent to the low-temperature tank v.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A multi-energy coupled combined cooling, heating, and power (CCHP) system, characterized in that, It includes a double-effect lithium bromide absorption heat pump (100), a thermal storage device (300), and a gas turbine power generation system (200), wherein the thermal storage device (300) is connected to the double-effect lithium bromide absorption heat pump (100) and the gas turbine power generation system (200), and the double-effect lithium bromide absorption heat pump (100) is connected to the gas turbine power generation system (200); It also includes a second regulating valve (f), and the heat storage device (300) includes a fourth heat exchanger (s), a high-temperature tank (t), a fifth heat exchanger (u), a sixth heat exchanger (w), and a low-temperature tank (v); The outlet of the gas turbine (c) in the gas turbine power generation system (200) is divided into two paths. One path is connected to the first regulating valve (e) in the gas turbine power generation system (200), and the other path is connected to the first opening of the second regulating valve (f). The second opening of the second regulating valve (f) is connected to the tube-side inlet of the fourth heat exchanger (s). The tube-side outlet of the fourth heat exchanger (s) is connected to the shell side of the sixth heat exchanger (w). The shell-side outlet of the fourth heat exchanger (s) is connected to the inlet of the high-temperature tank (t). The outlet of the high-temperature tank (t) is connected to the shell-side inlet of the fifth heat exchanger (u). The shell-side outlet of the fifth heat exchanger (u) is connected to the inlet of the low-temperature tank (v). The outlet of the low-temperature tank (v) is connected to the shell-side inlet of the fourth heat exchanger (s). The third opening of the second regulating valve (f) is connected to the high-pressure generator (g) in the double-effect lithium bromide absorption heat pump (100); the flue gas outlet of the high-pressure generator (g) in the double-effect lithium bromide absorption heat pump (100) is divided into two paths, one of which is connected to the tube-side inlet of the fifth heat exchanger (u), and the other is connected to the shell side of the second heat exchanger (i) in the double-effect lithium bromide absorption heat pump (100). The tube-side outlet of the fifth heat exchanger (u) is connected to the flue gas inlet of the high-pressure generator (g) in the double-effect lithium bromide absorption heat pump (100).

2. A multi-energy coupled combined cooling, heating, and power (CCHP) method, characterized in that, The multi-energy coupled combined cooling, heating and power system according to claim 1 includes the following steps: During heating, the high-temperature flue gas generated by the gas turbine (c) is used as a high-temperature heat source and enters the high-pressure generator (g) in the double-effect lithium bromide absorption heat pump (100) through the second regulating valve (f) for waste heat recovery. The air conditioning hot water under heating conditions is generated through the absorber (l) and condenser (q) in the double-effect lithium bromide absorption heat pump (100). The flue gas discharged from the high-pressure generator (g) enters the second heat exchanger (i) to generate low-temperature hot water, which serves as the low-temperature heat source required by the evaporator (o) in the double-effect lithium bromide absorption heat pump (100). The low-temperature flue gas discharged from the second heat exchanger (i) enters the atmosphere. Under refrigeration conditions, the gas turbine (c) generates high-temperature flue gas, which serves as a high-temperature heat source. The flue gas then enters the high-pressure generator (g) within the double-effect lithium bromide absorption heat pump (100) via the second regulating valve (f). The high-pressure generator (g) absorbs the heat from the high-temperature flue gas and generates steam. The generated steam is then cooled by the absorber (l) and condenser (q) to produce chilled water under refrigeration conditions.

3. The multi-energy coupled combined cooling, heating, and power (CCHP) method according to claim 2, characterized in that, When the high-temperature flue gas generated by the gas turbine (c) has unused flue gas after meeting the heating requirements of the dual-effect lithium bromide absorption heat pump (100), the high-temperature flue gas generated by the gas turbine (c) is divided into two paths. One path enters the high-pressure generator (g) in the dual-effect lithium bromide absorption heat pump (100) to produce the required air conditioning hot water, and the other path enters the fourth heat exchanger (s) to heat the molten salt in the low-temperature tank (v).

4. The multi-energy coupled combined cooling, heating, and power (CCHP) method according to claim 3, characterized in that, The heated molten salt output from the fourth heat exchanger (s) enters the high-temperature tank (t) for storage.

5. The multi-energy coupled combined cooling, heating, and power (CCHP) method according to claim 3, characterized in that, The flue gas discharged from the fourth heat exchanger (S) enters the sixth heat exchanger (W) to produce the domestic hot water required by the user.

6. The multi-energy coupled combined cooling, heating, and power (CCHP) method according to claim 2, characterized in that, When the high-temperature flue gas generated by the gas turbine (c) enters the double-effect lithium bromide absorption heat pump (100) and still cannot meet the user's demand for hot water for air conditioning, the high-temperature flue gas discharged from the high-pressure generator (g) in the double-effect lithium bromide absorption heat pump (100) is led out and sent to the fifth heat exchanger (u). It is heated into high-temperature flue gas by molten salt in the high-temperature tank (t) and then sent to the high-pressure generator (g) in the double-effect lithium bromide absorption heat pump (100) to generate hot water for air conditioning under heating conditions and meet the demand for air conditioning water.

7. The multi-energy coupled combined cooling, heating, and power (CCHP) method according to claim 6, characterized in that, The cooled molten salt output from the fifth heat exchanger (u) enters the cryogenic tank (v) for storage.

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