Efficient combined heat and power generation type energy supply system integrating deep refrigeration

Abstract

The utility model discloses an efficient combined heat and power generation type energy supply system integrating deep refrigeration in the technical field of refrigeration. The efficient combined heat and power generation type energy supply system comprises a boiler, heat utilization equipment and power generation equipment, a low-temperature absorption type refrigerating system is arranged on the power generation equipment, comprises a plurality of low-temperature absorption type refrigerating units and is used for preparing cooling capacity at different temperatures by using low-pressure steam discharged by the power generation equipment as a heat source; by innovatively coupling the low-temperature absorption refrigeration system, the problem that the boiler and the back pressure steam turbine in a traditional combined heat and power generation system are low in operation efficiency under the low-load working condition is effectively solved, on the basis of achieving combined heat and power supply, the depth of gradient utilization of energy is expanded, and the energy utilization efficiency is improved. High-grade cooling capacity covering the wide temperature range of-40 DEG C to 0 DEG C can be stably prepared, and the technical bottleneck that a conventional lithium bromide absorption type refrigerating unit cannot prepare low-temperature cooling capacity below 0 DEG C is overcome.

Description

Technical Field

[0001] The utility model relates to the field of refrigeration, and in particular to a high-efficiency cogeneration energy supply system with integrated deep refrigeration. Background Art

[0002] Generally, a trigeneration energy supply system (abbreviated as trigeneration system) refers to a system that simultaneously supplies electricity, heat and cooling to devices, facilities or buildings. Traditional trigeneration systems generate electricity and heat for devices, facilities or buildings, while using the waste heat and electricity generated in the cogeneration process to start absorption chillers, adsorption chillers or compression chillers to cool and provide the required cooling energy. Especially in summer, the demand for heating usually decreases significantly while the demand for cooling increases significantly. From the perspective of improving the utilization efficiency of energy production facilities, it is very important to improve the operating efficiency of equipment and the efficiency of waste heat utilization in the cogeneration process.

[0003] Publication number CN118008505A discloses a structure that combines a gas-fired distributed energy station trigeneration system with a lithium bromide absorption refrigeration system that uses waste heat generated during the cogeneration process for refrigeration. The problem with this technology is that compared with low-temperature absorption refrigeration systems, the temperature of the cold energy produced by the lithium bromide absorption refrigeration system is higher, and the temperature of the cold energy produced by the lithium bromide absorption refrigeration system is generally greater than 5°C. Utility Model Content

[0004] The purpose of the utility model is to provide a high-efficiency cogeneration energy supply system with integrated deep refrigeration, which solves the problem that the temperature of the cold energy produced by the existing lithium bromide absorption refrigeration system is relatively high.

[0005] The utility model achieves the above-mentioned purpose through the following technical solutions: a high-efficiency cogeneration energy supply system with integrated deep refrigeration, comprising: a boiler and heat-using equipment and power generation equipment connected to the boiler;

[0006] The power generation equipment is provided with a low-temperature absorption refrigeration system, which includes a plurality of low-temperature absorption refrigeration units for producing cold at different temperatures using the low-pressure steam discharged from the power generation equipment as a heat source.

[0007] Preferably, the cooling temperature of the plurality of low-temperature absorption refrigeration units is -40°C to 0°C.

[0008] Preferably, the low-temperature absorption refrigeration unit includes a generator, a condenser, a buffer tank, an evaporator, an absorber and a solution pump.

[0009] Preferably, the low-temperature absorption refrigeration unit further includes a first heat exchanger and a second heat exchanger;

[0010] The first heat exchanger is used to exchange heat between the liquid refrigerant input from the buffer tank to the evaporator and the gaseous refrigerant input from the evaporator to the absorber, and the second heat exchanger is used to exchange heat between the rich liquid input from the absorber to the generator and the lean liquid input from the generator to the absorber.

[0011] Preferably, the power generation equipment includes a back-pressure steam turbine, a radial steam turbine and two generator sets connected to the back-pressure steam turbine and the radial steam turbine respectively, the back-pressure steam turbine uses the high-pressure superheated steam generated by the boiler to drive one generator set to generate electricity, and the radial steam turbine uses the low-pressure steam discharged from the back-pressure steam turbine to drive the other generator set to generate electricity.

[0012] Preferably, a pressure reducing valve is provided between the boiler and the heat-consuming equipment.

[0013] The beneficial effects of the present invention are: by innovatively coupling a low-temperature absorption refrigeration system, the problem of low operating efficiency of boilers and back-pressure turbines in traditional cogeneration systems under low-load conditions is effectively solved. On the basis of realizing cogeneration of heat and power, the depth of energy cascade utilization is expanded, and high-quality cooling capacity covering a wide temperature range of -40°C to 0°C can be stably produced, overcoming the technical bottleneck that conventional lithium bromide absorption refrigeration units cannot produce low-temperature cooling capacity below 0°C. At the same time, within the same deep refrigeration temperature range, compared with compression refrigeration units that rely on high-quality electricity, this system significantly reduces the power consumption of the refrigeration process, thereby significantly reducing the overall power consumption load and operating costs of cold-using enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the utility model's high-efficiency cogeneration energy center station system;

[0015] Figure 2 This is a structural diagram of the low-temperature absorption refrigeration unit of the utility model.

[0016] In the figure: 1. Boiler; 2. Pressure reducing valve; 3. Power generation equipment; 31. Back-pressure steam turbine; 32. Radial steam turbine; 33. Generator set; 4. Low-temperature absorption refrigeration system; 41. Generator; 42. Condenser; 43. Buffer tank; 44. First heat exchanger; 45. Evaporator; 46. Absorber; 47. Solution pump; 48. Second heat exchanger. DETAILED DESCRIPTION

[0017] The present application is described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0018] See also Figure 1 A high-efficiency cogeneration energy supply system with integrated deep refrigeration includes: a boiler 1, the steam outlet of the boiler 1 is connected to a heat-consuming device and a power generation device 3 respectively; a low-temperature absorption refrigeration system 4 is provided on the steam outlet of the power generation device 3, and the low-temperature absorption refrigeration system 4 includes several low-temperature absorption refrigeration units.

[0019] It should be noted that the heat from the combustion of fuel is used to heat the water in the boiler 1 to generate high-temperature and high-pressure superheated steam. Part of the high-pressure superheated steam is used by the heat-using equipment, and part of the high-pressure superheated steam enters the power generation equipment 3 to drive it to generate electricity; several low-temperature absorption refrigeration units use the low-pressure steam discharged from the power generation equipment 3 as a heat source to produce cold at different temperatures (according to the demand for cold, the low-pressure steam is introduced into different low-temperature absorption refrigeration units to produce cold at different temperatures; the refrigerant is ammonia, which is the same for all low-temperature absorption refrigeration units. Because different pressures of ammonia correspond to different saturation temperatures, controlling the pressure of the evaporator 45 in the low-temperature absorption refrigeration unit can produce cold at different temperatures) to provide cold for the cold-using equipment.

[0020] It should also be noted that the heat source (low-pressure steam) used by the low-temperature absorption refrigeration unit is returned to the boiler 1 for continued circulation.

[0021] In this embodiment, as a further optimization solution, please refer to Figure 1 , several low-temperature absorption refrigeration units produce cooling capacity in the temperature range of -40℃ to 0℃.

[0022] In this embodiment, as a further optimization solution, please refer to Figure 2The low-temperature absorption refrigeration unit includes a generator 41, a condenser 42, a buffer tank 43, an evaporator 45, an absorber 46 and a solution pump 47; a medium-pressure gaseous refrigerant outlet, a lean liquid outlet and a rich liquid inlet are provided on the shell side of the generator 41, a heat source circulates in the tube side of the generator 41, a medium-pressure gaseous refrigerant inlet and a medium-pressure liquid refrigerant outlet are provided on the shell side of the condenser 42, circulating water circulates in the tube side of the condenser 42, a low-pressure liquid refrigerant inlet and a low-pressure gaseous refrigerant outlet are provided on the shell side of the evaporator 45, a secondary refrigerant circulates in the tube side of the evaporator 45, a lean liquid inlet, a rich liquid outlet and a low-pressure gaseous refrigerant inlet are provided on the shell side of the absorber 46, and the tube side of the absorber 46 is provided with a lean liquid inlet, a rich liquid outlet and a low-pressure gaseous refrigerant inlet. Circulating water circulates in the process; the medium-pressure gaseous refrigerant outlet of the generator 41 is connected to the medium-pressure gaseous refrigerant inlet of the condenser 42 through a pipeline, the rich liquid inlet of the generator 41 is connected to the outlet of the solution pump 47, the inlet of the solution pump 47 is connected to the rich liquid outlet of the absorber 46 through a pipeline, the lean liquid outlet of the generator 41 is connected to the lean liquid inlet of the absorber 46 through a pipeline, the medium-pressure liquid refrigerant outlet of the condenser 42 is connected to the inlet of the buffer tank 43 through a pipeline, the outlet of the buffer tank 43 is connected to the low-pressure liquid refrigerant inlet of the evaporator 45 (an expansion valve is provided between the two), and the low-pressure gaseous refrigerant outlet of the evaporator 45 is connected to the low-pressure gaseous refrigerant inlet of the absorber 46 through a pipeline.

[0023] It should be noted that the low-pressure steam discharged from the power generation equipment 3 enters the tube side of the generator 41, heats the rich solution therein, and converts it into a lean solution and a medium-pressure gaseous refrigerant. After use, the low-pressure steam is converted into steam condensate and sent to the boiler 1. The lean solution is discharged from the lean liquid outlet and sent to the absorber 46. The medium-pressure gaseous refrigerant is discharged from the medium-pressure gaseous refrigerant outlet and enters the shell side of the condenser 42. After being condensed into a medium-pressure liquid refrigerant by the circulating water flowing in its tube side, it enters the buffer tank 43; the medium-pressure liquid refrigerant is reduced in pressure to become a low-pressure liquid refrigerant through the expansion valve, and enters the shell side of the evaporator 45, exchanges heat with the coolant flowing in its tube side, vaporizes itself into a low-pressure gaseous refrigerant, and reduces the temperature of the coolant; the low-pressure gaseous refrigerant enters the shell side of the absorber 46, mixes with the lean solution to form a rich solution, and the rich solution is transported to the shell side of the generator 41 by the solution pump 47 to continue circulation.

[0024] In this embodiment, as a further optimization solution, please refer to Figure 2The low-temperature absorption refrigeration unit also includes a first heat exchanger 44 and a second heat exchanger 48; the two ends of the tube side of the first heat exchanger 44 are respectively connected to the outlet of the buffer tank 43 and the low-pressure liquid refrigerant inlet of the evaporator 45, and the shell side inlet and outlet of the first heat exchanger 44 are respectively located at the low-pressure gaseous refrigerant outlet of the evaporator 45 and the low-pressure gaseous refrigerant inlet of the absorber 46; the two ends of the tube side of the second heat exchanger 48 are respectively connected to the lean liquid outlet of the generator 41 and the lean liquid inlet of the absorber 46, and the shell side inlet and outlet of the second heat exchanger 48 are respectively connected to the outlet of the solution pump 47 and the rich liquid inlet of the generator 41; the first heat exchanger 44 is used to exchange heat between the liquid refrigerant input into the evaporator 45 from the buffer tank 43 and the gaseous refrigerant input into the absorber 46 from the evaporator 45 (to cool the liquid refrigerant and heat the gaseous refrigerant), and the second heat exchanger 48 is used to exchange heat between the rich liquid input into the generator 41 from the absorber 46 and the lean liquid input into the absorber 46 from the generator 41.

[0025] In this embodiment, as a further optimization solution, please refer to Figure 1 The power generation equipment 3 includes a back-pressure steam turbine 31, a radial steam turbine 32, and two generator sets 33 connected to the back-pressure steam turbine 31 and the radial steam turbine 32 respectively; the high-pressure superheated steam generated by the boiler 1 enters the back-pressure steam turbine 31 to expand and perform work, driving the generator set 33 connected to the back-pressure steam turbine 31 to operate and generate electricity; the low-pressure steam discharged from the back-pressure steam turbine 31 enters the radial steam turbine 32 to expand and perform work, driving the generator set 33 connected to the radial steam turbine 32 to operate and generate electricity.

[0026] It should be noted that the back-pressure steam turbine 31 , the radial steam turbine 32 and the generator set 33 are connected via couplings.

[0027] In this embodiment, as a further optimization solution, please refer to Figure 1 A pressure reducing valve 2 is provided between the boiler 1 and the heat-using equipment to reduce the pressure and temperature of the high-temperature and high-pressure steam generated by the boiler 1 into saturated steam for use by the heat-using equipment.

[0028] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A high-efficiency cogeneration energy supply system with integrated deep cooling, characterized in that: include: A boiler (1) and heat-using equipment and power generation equipment (3) connected to the boiler (1); The power generation equipment (3) is provided with a low-temperature absorption refrigeration system (4), which includes a plurality of low-temperature absorption refrigeration units for producing cold at different temperatures using low-pressure steam discharged from the power generation equipment (3) as a heat source.

2. The high-efficiency cogeneration energy supply system with integrated deep cooling according to claim 1, characterized in that: The cooling temperature of the plurality of low-temperature absorption refrigeration units is -40°C to 0°C.

3. The high-efficiency cogeneration energy supply system with integrated deep cooling according to claim 1, characterized in that: The low-temperature absorption refrigeration unit comprises a generator (41), a condenser (42), a buffer tank (43), an evaporator (45), an absorber (46), and a solution pump (47).

4. The high-efficiency cogeneration energy supply system with integrated deep cooling according to claim 3 is characterized in that: The low-temperature absorption refrigeration unit further includes a first heat exchanger (44) and a second heat exchanger (48); The first heat exchanger (44) is used to exchange heat between the liquid refrigerant input from the buffer tank (43) into the evaporator (45) and the gaseous refrigerant input from the evaporator (45) into the absorber (46), and the second heat exchanger (48) is used to exchange heat between the rich liquid input from the absorber (46) into the generator (41) and the lean liquid input from the generator (41) into the absorber (46).

5. The high-efficiency cogeneration energy supply system with integrated deep cooling according to claim 1, characterized in that: The power generation equipment (3) includes a back-pressure steam turbine (31), a radial steam turbine (32), and two generator sets (33) respectively connected to the back-pressure steam turbine (31) and the radial steam turbine (32). The back-pressure steam turbine (31) uses the high-pressure superheated steam generated by the boiler (1) to drive one generator set (33) to generate electricity, and the radial steam turbine (32) uses the low-pressure steam discharged from the back-pressure steam turbine (31) to drive the other generator set (33) to generate electricity.

6. The high-efficiency cogeneration energy supply system with integrated deep cooling according to claim 1, characterized in that: A pressure reducing valve (2) is provided between the boiler (1) and the heat-using equipment.

Images