阅读说明：本技术 一种基于热泵及制冷系统的凝汽器余热回收利用系统及方法 (Condenser waste heat recycling system and method based on heat pump and refrigerating system ) 是由 杨珍帅 万超 荆涛 韩立 邹洋 李高潮 贾明晓 王明勇 于 2021-10-15 设计创作，主要内容包括：本发明公开了一种基于热泵及制冷系统的凝汽器余热回收利用系统及方法,该系统将热泵系统、制冷系统以及凝汽器相耦合,实现了凝汽器余热利用,提高了凝汽器的真空度,减小了凝结水的过冷度,提高整个热力系统经济性。利用热泵系统将汽轮机排汽的热量回收,降低了排汽进入凝汽器的温度,降低了排汽进入凝汽器的温度,增大了凝汽器的真空度,降低了汽轮机的背压,增大了汽轮机的出力,同时,热泵产生的热量用于加热工业热水。利用制冷系统中冷却剂冷凝放热加热凝结水,减小了凝结水的过冷度,降低了凝结水中的氧汽含量,提高机组的热经济性能,同时,制冷系统中产生的冷冻水供给工厂。(The invention discloses a condenser waste heat recycling system and method based on a heat pump and a refrigerating system. The heat recovery of the steam turbine exhaust is realized by utilizing the heat pump system, the temperature of the exhaust entering the condenser is reduced, the vacuum degree of the condenser is increased, the back pressure of the steam turbine is reduced, the output of the steam turbine is increased, and meanwhile, the heat generated by the heat pump is used for heating industrial hot water. The condensate water is heated by utilizing the condensation heat release of the coolant in the refrigeration system, the supercooling degree of the condensate water is reduced, the oxygen content in the condensate water is reduced, the heat economical performance of the unit is improved, and meanwhile, the chilled water generated in the refrigeration system is supplied to a factory.)

1. A condenser waste heat recycling system based on a heat pump and a refrigerating system is characterized by comprising a condenser (1), a first evaporator (2), a compressor (3), a first condenser (4), a second condenser (7) and a second evaporator (10);

the output end of the compressor (3) is divided into two branches, the first branch is connected with the hot side inlet of the second condenser (7), the hot side outlet of the second condenser (7) is connected with the cold side inlet of the second evaporator (10), and the cold side outlet of the second evaporator (10) is connected with the compressor (3); the second branch is connected with a hot side inlet of the first condenser (4), a hot side outlet of the first condenser (4) is connected with a cold side inlet of the first evaporator (2), and a cold side outlet of the first evaporator (2) is connected with the compressor (3);

the exhaust steam of the steam turbine is connected with a hot side inlet of the first evaporator (2), a hot side outlet of the first evaporator (2) is connected with a hot side inlet of the condenser (1), and a condensed water outlet of the condenser (1) is connected with a cold side inlet of the second condenser (7).

2. The condenser waste heat recycling system based on the heat pump and the refrigerating system as recited in claim 1, wherein the condensed water outlet of the second condenser (7) is connected to a hot well.

3. The condenser waste heat recycling system based on the heat pump and the refrigerating system as claimed in claim 1, wherein a hot side inlet of the second evaporator (10) is communicated with an industrial freezing water inlet pipe (15), and a hot side outlet of the second evaporator (10) is communicated with an industrial freezing water outlet pipe (16).

4. The condenser waste heat recycling system based on the heat pump and the refrigerating system as recited in claim 1, characterized in that a cold side inlet of the first condenser (4) is communicated with an industrial hot water inlet pipe (13), and a cold side outlet of the first condenser (4) is communicated with an industrial hot water outlet pipe (14).

5. The condenser waste heat recycling system based on the heat pump and the refrigerating system as claimed in claim 1, wherein a cold side inlet of the condenser (1) is communicated with a circulating water inlet pipeline (11), and a cold side outlet of the condenser (1) is communicated with a circulating water outlet pipeline (12).

6. The condenser waste heat recycling system based on the heat pump and the refrigerating system as claimed in claim 1, characterized in that a first electric stop valve (5) and a first throttle valve (6) are sequentially arranged on a cold side outlet of the first condenser (4) and a cold side inlet connecting pipeline of the first evaporator (2) along the flowing direction of the coolant.

7. The condenser waste heat recycling system based on the heat pump and the refrigerating system as claimed in claim 1, wherein a second electric stop valve (8) and a second throttle valve (9) are sequentially arranged on a connection pipeline between a hot side outlet of the second condenser (7) and a cold side inlet of the second evaporator (10) along a flowing direction of the coolant.

8. The utilization method of the condenser waste heat recovery and utilization system based on the heat pump and the refrigeration system is characterized by comprising the following steps of:

after being pressurized by the compressor (3), the refrigerant respectively flows into the second condenser (7) through the first branch and flows into the first condenser (4) through the second branch; after the refrigerant exchanges heat with the condensed water flowing out of the condenser (1) in the second condenser (7), the refrigerant is cooled in the second condenser (7), then flows into the second evaporator (10), and after absorbing heat in the second evaporator (10), the refrigerant flows back to the compressor (3);

after being cooled in the first condenser (4), the refrigerant flows into the first evaporator (2), and flows back to the compressor (3) after being heated by the steam turbine exhaust steam in the first evaporator (2);

the turbine exhaust steam enters the condenser (1) after being cooled in the first evaporator (2), and the turbine exhaust steam enters the second condenser (7) after being cooled in the condenser (1).

9. The utilization method according to claim 8, wherein the refrigerant is R22 or R245 fa.

Technical Field

The invention belongs to the field of energy conservation of power plants, and particularly relates to a condenser waste heat recycling system and method based on a heat pump and a refrigerating system.

Background

At present, a power supply structure is mainly thermal power generation, wherein coal-fired power generation is dominant in thermal power generation. Under the influence of national coal-electricity stop and slow-construction policies, the increase of installed capacity of thermal power generation is obviously restrained. In addition, in recent years, under the influence of policies such as environmental protection and power supply structure reformation, the installation of domestic non-fossil energy is rapidly increased, the proportion of thermal power installation capacity to electric power installation capacity is in a situation of slightly decreasing year by year, the trend is not maintained for a long time, but at the same time, under the influence of factors such as energy structure and historical electric power installation layout, the domestic power supply structure still mainly uses thermal power for a long time. Under the long-term trend and the large background, it is important to actively explore clean and efficient thermal power generation technology.

The working principle of the coal-fired power generation system is that superheated steam generated by a boiler enters a steam turbine to expand to do work to drive a generator to generate power, and exhaust steam after doing work is sent back to the boiler for recycling through a condenser, a condensate pump, a feed water heater and the like. Taking a water cooling unit as an example, the exhaust steam of the steam turbine enters a condenser and then is cooled into liquid water by circulating water, a certain vacuum degree is formed in the condenser, and the higher the vacuum degree of the condenser is, the lower the exhaust steam back pressure of the steam turbine is, so that the more the output of the steam turbine is. At present, the exhaust back pressure of a steam turbine is indirectly adjusted by adjusting the flow rate of circulating water in a power plant, and the adjusting effect is limited.

Meanwhile, the condensate water at the outlet of the condenser has a certain degree of supercooling, the higher the degree of supercooling is, the more the lost heat taken away by the cooling water is, and the heat loss of the part is compensated by the more fuel burned by the boiler, so that the economic efficiency of the whole thermodynamic system is reduced. And the larger the supercooling degree is, the more the oxygen content in the condensed water is, thereby accelerating the corrosion speed of related pipelines and equipment. Therefore, the supercooling degree of the condensed water needs to be considered and measures are taken to be minimized from various aspects so as to improve the economical efficiency and the safety of the unit operation.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a condenser waste heat recycling system and method based on a heat pump and a refrigerating system so as to solve the problem of excessive supercooling degree of condensed water in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a condenser waste heat recycling system based on a heat pump and a refrigerating system comprises a condenser, a first evaporator, a compressor, a first condenser, a second condenser and a second evaporator;

the output end of the compressor is divided into two branches, the first branch is connected with a hot side inlet of the second condenser, a hot side outlet of the second condenser is connected with a cold side inlet of the second evaporator, and a cold side outlet of the second evaporator is connected with the compressor; the second branch is connected with a hot side inlet of the first condenser, a hot side outlet of the first condenser is connected with a cold side inlet of the first evaporator, and a cold side outlet of the first evaporator is connected with the compressor;

the exhaust steam of the steam turbine is connected with a hot side inlet of the first evaporator, a hot side outlet of the first evaporator is connected with a hot side inlet of the condenser, and a condensed water outlet of the condenser is connected with a cold side inlet of the second condenser.

The invention is further improved in that:

preferably, the condensed water outlet of the second condenser is connected to a hot water well.

Preferably, the hot-side inlet of the second evaporator is communicated with an industrial freezing water inlet pipeline, and the hot-side outlet of the second evaporator is communicated with an industrial freezing water outlet pipeline.

Preferably, the cold side inlet of the first condenser is communicated with an industrial hot water inlet pipeline, and the cold side outlet of the first condenser is communicated with an industrial hot water outlet pipeline.

Preferably, a cold side inlet of the condenser is communicated with a circulating water inlet pipeline, and a cold side outlet of the condenser is communicated with a circulating water outlet pipeline.

Preferably, a first electric stop valve and a first throttle valve are sequentially arranged on the cold-side outlet of the first condenser and the cold-side inlet connecting pipeline of the first evaporator along the flowing direction of the coolant.

Preferably, a second electric cut-off valve and a second throttle valve are sequentially arranged on a hot side outlet of the second condenser and a cold side inlet connecting pipeline of the second evaporator along the flowing direction of the coolant.

A utilization method of a condenser waste heat recycling system based on a heat pump and a refrigerating system comprises the following steps:

after being pressurized by the compressor, the refrigerant respectively flows into the second condenser through the first branch and flows into the first condenser through the second branch; after the refrigerant exchanges heat with condensed water flowing out of the condenser in the second condenser, the refrigerant is cooled in the second condenser and then flows into the second evaporator, and the refrigerant absorbs heat in the second evaporator and then flows back to the compressor;

after being cooled in the first condenser, the refrigerant flows into the first evaporator, and flows back to the compressor after being heated by the steam turbine exhaust steam in the first evaporator;

and the exhaust steam of the turbine enters the condenser after being cooled in the first evaporator, and the exhaust steam of the turbine enters the second condenser after being cooled in the condenser.

Preferably, the refrigerant is R22 or R245 fa.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a condenser waste heat recycling system based on a heat pump and a refrigerating system, which couples the heat pump system, the refrigerating system and a condenser, realizes the utilization of the waste heat of the condenser, improves the vacuum degree of the condenser, reduces the supercooling degree of condensed water, and improves the economy of the whole thermodynamic system. The heat recovery of the steam turbine exhaust is realized by utilizing the heat pump system, the temperature of the exhaust entering the condenser is reduced, the vacuum degree of the condenser is increased, the back pressure of the steam turbine is reduced, the output of the steam turbine is increased, and meanwhile, the heat generated by the heat pump is used for heating industrial hot water. The condensate water is heated by utilizing the condensation heat release of the coolant in the refrigeration system, the supercooling degree of the condensate water is reduced, the oxygen content in the condensate water is reduced, the heat economical performance of the unit is improved, and meanwhile, the chilled water generated in the refrigeration system is supplied to a factory. According to the invention, the steam turbine provides electric energy to the outside, the heat pump system provides industrial hot water to the outside, and the refrigerating system provides industrial chilled water to the outside, so that the combined production of cold, heat and electricity of the coal-fired power plant is realized, the energy efficiency of the system is improved, and the cascade utilization of energy is realized.

The invention also discloses a utilization method of the condenser waste heat recycling system based on the heat pump and the refrigeration system, the method absorbs part of heat of the steam turbine exhaust by the heat pump technology, and reduces the heat exchange temperature difference between the steam turbine exhaust and circulating water in the condenser, thereby improving the vacuum degree of the condenser, reducing the back pressure of the steam turbine and increasing the output of the steam turbine; meanwhile, the refrigerant in the condenser of the refrigerating system is used for releasing heat to heat condensed water at the outlet of the condenser, the supercooling degree of the condensed water is reduced, and the economical efficiency of the whole thermodynamic system is improved. Inherent cold source loss exists in the thermal power conversion process of the power plant, and the circulating heat efficiency of the modern power plant is generally 40% -57%, so that the heat economy of the power plant can be effectively improved by recycling the waste heat of the condenser, and the energy-saving effect is obvious.

Drawings

Fig. 1 is a condenser waste heat recovery system based on a heat pump-refrigeration system.

In fig. 1: 1-a condenser; 2-a first evaporator; 3-a compressor; 4-a first condenser; 5-a first electrically powered stop valve; 6-a first throttle valve; 7-a second condenser; 8-a second electrically powered stop valve; 9-a second throttle valve; 10-a second evaporator; 11-a circulating water inlet pipeline; 12-circulating water outlet pipeline; 13-industrial hot water inlet pipe; 14-industrial hot water outlet pipe; 15-industrial chilled water inlet pipe; 16-industrial chilled water outlet pipeline.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and encompass, for example, both fixed and removable connections; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention is realized by the following technical scheme: a condenser waste heat recycling system based on a heat pump and a refrigerating system mainly comprises a condenser, a heat pump system and the refrigerating system.

As shown in fig. 1, a condenser waste heat recovery system based on a heat pump and a refrigeration system is composed of a condenser 1, a first evaporator 2, a compressor 3, a first condenser 4, a first electric stop valve 5, a first throttle valve 6, a second condenser 7, a second electric stop valve 8, a second throttle valve 9, a second evaporator 10, a circulating water inlet pipe 11, a circulating water outlet pipe 12, an industrial hot water inlet pipe 13, an industrial hot water outlet pipe 14, an industrial chilled water inlet pipe 15 and an industrial chilled water outlet pipe 16.

The heat pump system and the refrigeration system share the same compressor 3, and refrigerant is pressurized by the compressor 3 and then divided into two parts which respectively enter the heat pump system and the refrigeration system. The heat pump system comprises a first condenser 4, a first electric stop valve 5, a first throttle valve 6 and a first evaporator 2; the refrigeration system includes a second condenser 7, a second electrically-operated shutoff valve 8, a second throttle valve 9, and a second evaporator 10.

The refrigerant output end of the compressor 3 of the system is divided into two branches, the first branch leads to the refrigeration system, and the second branch leads to the heat pump system.

More specifically, the first branch is connected to a hot-side inlet of the second condenser 7, a hot-side outlet of the second condenser 7 is connected to a cold-side inlet of the second evaporator 10, a cold-side inlet of the second condenser 7 is connected to a condensed water outlet of the condenser 1, and a cold-side outlet of the second condenser 7 is connected to a hot water well. The cold side inlet of the second evaporator 10 is connected to the hot side outlet of the second condenser 7 and the cold side outlet of the second evaporator 10 is connected to the inlet of the compressor 3. The hot side inlet of the second evaporator 10 is connected with an industrial freezing water inlet pipe 15, and the hot side outlet of the second evaporator 10 is communicated with an industrial freezing water outlet pipe 16. Along the flowing direction of the coolant, a second electric stop valve 8 and a second throttle valve 9 are sequentially arranged on a hot side outlet of the second condenser 7 and a cold side inlet connecting pipeline of the second evaporator 10.

The second branch is connected with a hot side inlet of the first condenser 4, a hot side outlet of the first condenser 4 is connected with a cold side inlet of the first evaporator 2, a cold side inlet of the first condenser 4 is communicated with an industrial hot water inlet pipe 13, and a cold side outlet of the first condenser 4 is connected with an industrial hot water outlet pipe 14. Along the flow direction of the coolant, a first electric cut-off valve 5 and a first throttle valve 6 are sequentially provided on a cold-side outlet connection pipe of the first condenser 4 and a cold-side inlet connection pipe of the first evaporator 2.

The exhaust steam of the steam turbine is connected with the hot side inlet of the first evaporator 2, the hot side outlet of the first evaporator 2 is connected with the hot side inlet of the condenser 1, the cold side inlet of the second evaporator 10 is connected with the hot side outlet of the first condenser 4, and the cold side outlet of the second evaporator 10 is connected with the compressor 3.

And a hot side inlet of the condenser 1 is connected with a hot side outlet of the first evaporator 2, and a condensed water outlet of the condenser 1 is connected with a cold side inlet of the second condenser 7. And a cold side inlet of the condenser 1 is communicated with a circulating water inlet pipeline 11, and a cold side outlet of the condenser 1 is communicated with a circulating water outlet pipeline 12.

The refrigerant can be R22 or R245 fa.

Specifically, hot steam discharged by the steam turbine enters the first evaporator 2 to exchange heat with a refrigerant from the heat pump system, the cooled steam enters the condenser 1, circulating water enters the condenser 1 to exchange heat with the steam, and heat of the steam is taken away to form condensed water.

The condensed water has a certain supercooling degree after coming out of the condenser 1, enters the second condenser 7, is heated by the refrigerant from the refrigerating system, and is discharged into the hot water well after coming out of the second condenser 7.

A refrigerant in the heat pump system is pressurized by a compressor and then enters a first condenser 4 to exchange heat with water, and the heated water is supplied to a factory through an industrial hot water pipeline; the condensed refrigerant enters a first throttling valve 6 for throttling and pressure reduction, then enters a first evaporator 2 for exchanging heat with hot steam exhausted by a steam turbine, is heated and finally returns to a compressor 3.

In the refrigerating system, a refrigerant is pressurized by a compressor 3 and then enters a second condenser 7 to exchange heat with condensed water at the outlet of the condenser 1, the heated condensed water is discharged into a hot water well, the condensed refrigerant is throttled and depressurized by a second throttling valve 9 and enters a second evaporator 10 to exchange heat with water, the cooled water-cooled frozen water is supplied to a factory through an industrial chilled water pipeline, and the refrigerant after being heated and evaporated returns to the compressor.

The exhaust steam of the steam turbine enters the hot side of the first evaporator 2, exchanges heat with a refrigerant from the heat pump system in the first evaporator 2, and the cooled exhaust steam of the steam turbine enters the condenser 1. Circulating water enters the condenser 1 through a circulating water inlet pipeline 11, exchanges heat with steam turbine exhaust steam and then flows out of a circulating water outlet pipeline 12. And the condensed water from the condenser 1 enters the cold side of the second condenser 7, exchanges heat with the refrigerant in the refrigeration system and then flows into the hot water well.

The working process of the invention is as follows:

the refrigerant is pressurized by the compressor 3 and then divided into two parts, one part of the refrigerant enters the first condenser 4 to exchange heat with industrial hot water, the condensed refrigerant enters the first electric stop valve 5 and the first throttle valve 6 in sequence and then enters the cold side of the first evaporator 2 to cool the steam turbine for steam exhaust, and finally the refrigerant returns to the compressor 3. Water enters the cold side of the first condenser 4 through an industrial hot water inlet pipe 13, and flows out of an industrial hot water outlet pipe 14 to be supplied to a factory after being heated and warmed.

The other part of the refrigerant enters a second condenser 7 to exchange heat with the condensed water, and the condensed refrigerant enters a second electric stop valve 8 and a second throttle valve 9 in sequence, enters the cold side of a second evaporator 10 to absorb heat, and finally joins with the refrigerant of the heat pump system to return to the compressor 3 together. Water enters the hot side of the second evaporator through the industrial chilled water inlet pipe 15, and flows out of the industrial chilled water outlet pipe 16 after being cooled to be supplied to a factory.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.