A nuclear power unit heat and power cogeneration system using condensed water waste heat and a working method thereof

Abstract

The invention discloses a nuclear power unit heat and power cogeneration system and working method utilizing waste heat of condensed water, comprising a reactor, a steam generator and an absorption heat pump; the gas outlet of the reactor is connected to the hot end inlet of the steam generator; the absorption heat pump comprises a generator, a condenser, an evaporator and an absorber; the hot end inlet of the generator is connected to the hot end outlet of the steam generator, the hot end outlet of the generator is connected to the gas inlet of the reactor, the refrigerant outlet of the generator is sequentially connected to the hot end of the condenser, the cold end of the evaporator and the solution inlet of the absorber; the solution outlet of the generator is connected to the solution inlet of the absorber, and the solution outlet of the absorber is connected to the solution inlet of the generator; the cold end inlet of the absorber is connected to a heat network return water pipeline, and the cold end outlet of the absorber is connected to a heat network water supply pipeline. The waste heat of steam turbine exhaust of the nuclear power unit is fully utilized for heating, effectively improving the capacity utilization efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of clean energy heating, and relates to a nuclear power unit cogeneration system and a working method utilizing waste heat of condensed water. Background Art

[0002] Coal-fired heating is one of the most important factors causing winter smog. In cities with centralized heating in the north, coal-fired heating will cause a sharp increase in sulfur dioxide and dust particles in the air. Low temperature, weak wind and other meteorological conditions make the smog accumulate and not dissipate, resulting in long-term smog weather in the north, which has become a hot issue affecting the national economy and people's livelihood and the country's image. In addition, the harmful substances produced by coal-fired heating include carbon dioxide and sulfur dioxide. Carbon dioxide is the main substance of the greenhouse effect, and sulfur dioxide is easy to form acid rain. Therefore, coal-fired heating will bring serious environmental pollution problems, and there is an urgent need to promote clean energy heating.

[0003] As an important clean energy, nuclear energy has made great progress in recent years. However, nuclear power heating has not yet been widely used. It mainly generates electricity through steam extraction from steam turbines, and the thermal power generation is relatively small. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a nuclear power unit cogeneration system and working method that utilizes the waste heat of condensed water, fully utilize the waste heat of the nuclear power unit's turbine exhaust for heating, and effectively improve the capacity utilization efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A nuclear power unit cogeneration system utilizing waste heat from condensed water, comprising a reactor, a steam generator and an absorption heat pump;

[0007] The gas outlet of the reactor is connected to the hot end inlet of the steam generator;

[0008] The absorption heat pump includes a generator, a condenser, an evaporator and an absorber; the hot end inlet of the generator is connected to the hot end outlet of the steam generator, the hot end outlet of the generator is connected to the gas inlet of the reactor, the refrigerant outlet of the generator is connected to the hot end of the condenser, the cold end of the evaporator and the solution inlet of the absorber in sequence; the solution outlet of the generator is connected to the solution inlet of the absorber, and the solution outlet of the absorber is connected to the solution inlet of the generator; the cold end inlet of the absorber is connected to a heat network return pipe, and the cold end outlet of the absorber is connected to a heat network water supply pipe.

[0009] Preferably, steam is arranged in the cold end of the steam generator, the cold end outlet of the steam generator is connected to the inlet of the steam turbine, and the exhaust outlet of the steam turbine is connected to the cold end inlet of the steam generator.

[0010] Furthermore, the exhaust steam outlet of the steam turbine is connected to the hot end inlet of the evaporator, and the hot end outlet of the evaporator is connected to the cold end inlet of the steam generator.

[0011] Furthermore, a feedwater heater is arranged between the hot end outlet of the evaporator and the cold end inlet of the steam generator, the inlet and outlet of the cold end of the feedwater heater are respectively connected to the hot end outlet of the evaporator and the cold end inlet of the steam generator, and the steam extraction outlet of the turbine is connected to the hot end of the feedwater heater.

[0012] Preferably, the cold end of the condenser is connected between the cold end outlet of the absorber and the water supply pipeline of the heating network, the cold end outlet of the absorber is connected to the cold end inlet of the condenser, and the cold end outlet of the condenser is connected to the water supply pipeline of the heating network.

[0013] Preferably, a throttle valve is provided between the hot end of the condenser and the cold end of the evaporator.

[0014] Preferably, a circulation pump is provided between the solution outlet of the absorber and the solution inlet of the generator.

[0015] Preferably, the solution in the absorption heat pump is a lithium bromide solution.

[0016] A working method of a nuclear power unit cogeneration system utilizing waste heat of condensed water based on any one of the above, comprising the following process:

[0017] The high-temperature helium gas coming out of the reactor passes through the hot end of the steam generator and enters the hot end of the generator and then returns to the reactor; the dilute solution at the cold end of the generator is heated to evaporate the refrigerant, and the refrigerant vapor enters the hot end of the condenser, where it is condensed into refrigerant liquid; the refrigerant liquid enters the cold end of the evaporator, absorbs the heat in the hot end of the evaporator and is activated into refrigerant vapor under the evaporation pressure; the concentrated solution remaining after the generation process in the generator enters the absorber, mixes with the low-pressure refrigerant vapor coming out of the evaporator, absorbs the low-pressure refrigerant vapor and returns to its original concentration, and the solution with the restored concentration in the absorber is sent back to the generator to continue the cycle.

[0018] Preferably, the high-temperature helium gas from the reactor enters the hot end of the steam generator to heat the steam at the cold end of the steam generator to generate high-temperature steam for driving the steam turbine to generate power. The exhaust steam of the steam turbine enters the hot end of the evaporator to serve as a low-temperature heat source for the absorption heat pump, and then returns to the cold end of the steam generator through the cold end of the feedwater heater. The steam extraction outlet of the steam turbine enters the hot end of the feedwater heater to preheat the steam in the hot end of the feedwater heater.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention combines a nuclear power unit with an absorption heat pump, utilizes helium at the outlet of a steam generator as a high-temperature heat source for the absorption heat pump, improves the heating capacity of the nuclear power unit, increases thermal power, and effectively improves capacity utilization efficiency.

[0021] Furthermore, the waste heat from the steam turbine exhaust is used as the low-temperature heat source of the absorption heat pump, effectively improving the capacity utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0023] Among them: 1-reactor; 2-steam generator; 3-steam turbine; 4-feedwater heater; 5-generator; 6-condenser; 7-evaporator; 8-absorber; 9-throttle valve; 10-circulating pump. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0025] like Figure 1 As shown, the cogeneration system of a nuclear power unit utilizing waste heat of condensed water according to the present invention comprises a reactor 1, a steam generator 2, a steam turbine 3, a feed water heater 4, a generator 5, a condenser 6, an evaporator 7, an absorber 8, a throttle valve 9 and a circulating pump 10.

[0026] The absorption heat pump includes a generator 5, a condenser 6, an evaporator 7 and an absorber 8; the hot end inlet of the generator 5 is connected to the hot end outlet of the steam generator 2, the hot end outlet of the generator 5 is connected to the gas inlet of the reactor 1, the refrigerant outlet of the generator 5 is connected to the hot end of the condenser 6, the cold end of the evaporator 7 and the solution inlet of the absorber 8 in sequence; the solution outlet of the generator 5 is connected to the solution inlet of the absorber 8, and the solution outlet of the absorber 8 is connected to the solution inlet of the generator 5; the cold end inlet of the absorber 8 is connected to a heat network return pipe, and the cold end outlet of the absorber 8 is connected to a heat network water supply pipe.

[0027] The cold end of the condenser 6 is connected between the cold end outlet of the absorber 8 and the water supply pipeline of the heating network, the cold end outlet of the absorber 8 is connected to the cold end inlet of the condenser 6, and the cold end outlet of the condenser 6 is connected to the water supply pipeline of the heating network.

[0028] The gas outlet of the reactor 1 is connected to the hot end inlet of the steam generator 2; steam is arranged in the cold end of the steam generator 2, the cold end outlet of the steam generator 2 is connected to the inlet of the steam turbine 3, and the exhaust steam outlet of the steam turbine 3 is connected to the cold end inlet of the steam generator 2.

[0029] The hot end outlet of the condenser 6 is connected to the cold end inlet of the evaporator 7 through a throttle valve 9 , and the solution outlet of the absorber 8 is connected to the solution inlet of the generator 5 through a circulating pump 10 .

[0030] Steam is arranged in the cold end of the steam generator 2 , the cold end outlet of the steam generator 2 is connected to the inlet of the steam turbine 3 , and the exhaust steam outlet of the steam turbine 3 is connected to the cold end inlet of the steam generator 2 .

[0031] The exhaust steam outlet of the steam turbine 3 is connected to the hot end inlet of the evaporator 7 , and the hot end outlet of the evaporator 7 is connected to the cold end inlet of the steam generator 2 .

[0032] A feedwater heater 4 is arranged between the hot end outlet of the evaporator 7 and the cold end inlet of the steam generator 2. The inlet and outlet of the cold end of the feedwater heater 4 are respectively connected to the hot end outlet of the evaporator 7 and the cold end inlet of the steam generator 2. The steam extraction outlet of the turbine 3 is connected to the hot end of the feedwater heater 4.

[0033] The high-temperature helium from the reactor 1 enters the steam generator 2 to heat the steam, generating high-temperature steam to drive the steam turbine 3 to generate power. The steam at the outlet of the steam generator 2 enters the generator 5 as the high-temperature heat source of the absorption heat pump, and the steam at the outlet of the generator 5 returns to the reactor 1 to absorb heat. The exhaust steam of the steam turbine 3 enters the evaporator 7 for condensation and serves as the low-temperature heat source of the absorption heat pump. The feed water at the outlet of the evaporator 7 enters the feed water heater to be preheated by the extraction steam of the steam turbine 3, and then enters the steam generator 2 for heating.

[0034] The working medium in the absorption heat pump includes a refrigerant for producing cold and an absorbent solution for absorbing and desorbing the refrigerant, and the two constitute a working medium pair. In this embodiment, the absorbent solution adopts a lithium bromide solution; the dilute solution with a certain concentration delivered by the circulating pump 10 from the absorber 8 is heated in the generator 5 by high-temperature helium, and most of the low-boiling-point refrigerant in the solution is evaporated; the refrigerant vapor enters the hot end of the condenser 6 and condenses into a refrigerant liquid in the condenser 6; the refrigerant liquid enters the cold end of the evaporator 7, absorbs the heat in the hot end of the evaporator 7 and is activated into a refrigerant vapor under the evaporation pressure; the concentrated solution remaining after the generation process in the generator 5 enters the absorber 8, mixes with the low-pressure refrigerant vapor coming out of the evaporator 7, absorbs the low-pressure refrigerant vapor and restores to the original concentration, and the solution with the restored concentration in the absorber 8 is sent to the generator 5 to continue circulating; the absorption process is an exothermic process, so it is necessary to use hot network water in the absorber 8 to cool the mixed solution.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does 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 nuclear power unit cogeneration system utilizing waste heat from condensed water, characterized in that: It comprises a reactor (1), a steam generator (2) and an absorption heat pump; The gas outlet of the reactor (1) is connected to the hot end inlet of the steam generator (2); The absorption heat pump comprises a generator (5), a condenser (6), an evaporator (7) and an absorber (8); the hot end inlet of the generator (5) is connected to the hot end outlet of the steam generator (2), the hot end outlet of the generator (5) is connected to the gas inlet of the reactor (1), the refrigerant outlet of the generator (5) is connected to the hot end of the condenser (6), the cold end of the evaporator (7) and the solution inlet of the absorber (8) in sequence; the solution outlet of the generator (5) is connected to the solution inlet of the absorber (8), and the solution outlet of the absorber (8) is connected to the solution inlet of the generator (5); the cold end inlet of the absorber (8) is connected to a heat network return pipe, and the cold end outlet of the absorber (8) is connected to a heat network water supply pipe; Steam is arranged in the cold end of the steam generator (2); the cold end outlet of the steam generator (2) is connected to the inlet of the steam turbine (3); and the exhaust steam outlet of the steam turbine (3) is connected to the cold end inlet of the steam generator (2); The exhaust steam outlet of the steam turbine (3) is connected to the hot end inlet of the evaporator (7), and the hot end outlet of the evaporator (7) is connected to the cold end inlet of the steam generator (2); A feedwater heater (4) is provided between the hot end outlet of the evaporator (7) and the cold end inlet of the steam generator (2); the cold end inlet and outlet of the feedwater heater (4) are respectively connected to the hot end outlet of the evaporator (7) and the cold end inlet of the steam generator (2); and the steam extraction outlet of the steam turbine (3) is connected to the hot end of the feedwater heater (4); The cold end of the condenser (6) is connected between the cold end outlet of the absorber (8) and the water supply pipeline of the heating network, the cold end outlet of the absorber (8) is connected to the cold end inlet of the condenser (6), and the cold end outlet of the condenser (6) is connected to the water supply pipeline of the heating network.

2. The cogeneration system of a nuclear power unit utilizing waste heat of condensed water according to claim 1, characterized in that: A throttle valve (11) is provided between the hot end of the condenser (6) and the cold end of the evaporator (7).

3. The cogeneration system of a nuclear power unit utilizing waste heat of condensed water according to claim 1, characterized in that: A circulation pump (12) is provided between the solution outlet of the absorber (8) and the solution inlet of the generator (5).

4. The cogeneration system of a nuclear power unit utilizing waste heat of condensed water according to claim 1, characterized in that: The solution in the absorption heat pump is lithium bromide solution.

5. A method for operating a cogeneration system of a nuclear power plant unit utilizing waste heat of condensed water according to any one of claims 1 to 4, characterized in that: The process includes: The high-temperature helium gas from the reactor (1) passes through the hot end of the steam generator (2) and enters the hot end of the generator (5) and then returns to the reactor (1); the dilute solution at the cold end of the generator (5) is heated, causing the refrigerant to evaporate, and the refrigerant vapor enters the hot end of the condenser (6), where it is condensed into a refrigerant liquid; the refrigerant liquid enters the cold end of the evaporator (7), absorbs the heat in the hot end of the evaporator (7) and is activated into a refrigerant vapor at an evaporation pressure; the concentrated solution remaining after the generation process in the generator (5) enters the absorber (8), mixes with the low-pressure refrigerant vapor from the evaporator (7), absorbs the low-pressure refrigerant vapor and restores to its original concentration, and the solution whose concentration has been restored in the absorber (8) is sent back to the generator (5) to continue the cycle; High-temperature helium gas from the reactor (1) enters the hot end of the steam generator (2) to heat the steam at the cold end of the steam generator (2) to generate high-temperature steam for driving the steam turbine (3) to generate power. The exhaust steam of the steam turbine (3) enters the hot end of the evaporator (7) to serve as a low-temperature heat source for the absorption heat pump. It then passes through the cold end of the feedwater heater (4) and returns to the cold end of the steam generator (2). The steam extraction outlet of the steam turbine (3) enters the hot end of the feedwater heater (4) to preheat the steam in the hot end of the feedwater heater (4).

Images