Novel cooling system for combined cooling and heating

Abstract

The utility model provides a novel cooling system for combined cooling and heating, which is used for cooling dead steam generated by a steam turbine in a power generation system comprising a boiler and the steam turbine, and is characterized by comprising a steam pressurizing device, a cooling device and a cooling device, and the heat exchanger exchanges heat with the dead steam supercharged by the steam supercharging device through an external refrigerant, so that the dead steam is cooled to generate steam condensed water, and the steam condensed water is supplied to the boiler as boiler circulating water. By the adoption of the system, the dead steam cooling function of an existing cooling system is achieved in a power generation system, meanwhile, dead steam waste heat in dead steam can be recycled to the maximum degree, and full utilization of energy is achieved.

Description

Technical Field

[0001] The utility model relates to a new cooling system for combined heat and power supply, which is used for a power generation system including a boiler and a steam turbine to cool the exhaust steam generated by the steam turbine. Background Art

[0002] A thermal power plant is a factory that uses coal as the main fossil fuel to produce electric energy. Its basic production process is that fuel burns in a boiler to heat water to generate steam, converting the chemical energy of the fuel into heat energy. The steam enters the steam turbine to drive the steam turbine to rotate, converting the heat energy into mechanical energy. Then the steam turbine drives the generator to rotate, converting the mechanical energy into electric energy. As a unit for converting primary energy into secondary energy, a thermal power plant realizes the conversion of heat energy into mechanical energy based on the Rankine cycle, including four processes: isentropic compression in the feed water pump, isobaric heating in the boiler, adiabatic expansion in the steam turbine, and constant pressure heat release in the condenser.

[0003] The high-quality steam produced from the boiler side enters the steam turbine to drive the rotor to rotate and do work for power generation. The work process is also the process of the high-quality steam degrading into low-quality steam. When the steam degrades to the point where it no longer has the ability to continue expanding for power generation, the low-quality steam is discharged from the exhaust port of the steam turbine (the low-quality steam discharged from the exhaust port of the steam turbine is also called "exhaust steam"). Since the working medium needs to be pressurized in the feed water pump before entering the boiler for heating, it is necessary to first condense the exhaust steam into condensate before it can be pressurized by the feed water pump. Therefore, the cooling system is an irreplaceable part of the power generation cycle.

[0004] The existing cooling systems are divided into water cooling systems and air cooling systems.

[0005] A water cooling system refers to a cooling system with water as the medium, mainly composed of sub-systems such as a condenser, a cooling tower, a circulating water pump, and circulating cooling water. Its working principle is that low-temperature cooling water enters the condenser through the circulating water pump and exchanges heat with the exhaust steam on the surface. The exhaust steam is cooled to condensate after releasing heat on the shell side of the condenser, and the low-temperature cooling water is heated to high-temperature cooling water after absorbing heat on the tube side of the condenser. The high-temperature cooling water is sprayed and cooled in the cooling tower, and the heat is discharged into the atmosphere and then restored to low-temperature cooling water, which is then transported to the condenser again by the circulating water pump to complete the heat exchange cycle.

[0006] An air cooling system refers to a cooling system with air as the medium, which is further divided into a direct air cooling system and an indirect air cooling system.

[0007] The working principle of the direct air cooling system is that the exhaust steam is sent to the steam distribution pipes of each row of radiators arranged outdoors through the exhaust pipe. In the pipes of the radiator, the exhaust steam flows from top to bottom, and the cooling fans arranged under the radiator blow air to flow from bottom to top. The exhaust steam in the radiator and the air outside the radiator are cooled to condensate after surface heat exchange. That is, the exhaust steam in the pipe is cooled by the air flowing outside the pipe.

[0008] In an indirect air-cooling system, the exhaust steam is first cooled to condensate by exchanging heat with low-temperature cooling water in a condenser. The high-temperature cooling water heated by the exhaust steam is then convectively cooled with natural or mechanically ventilated air in the radiator of an air-cooling tower and restored to low-temperature cooling water, completing the heat exchange cycle. That is, the exhaust steam is first cooled by industrial cooling water, and then the industrial cooling water is cooled by air.

[0009] However, whether it is a water-cooling system or an air-cooling system, their functions and purposes are to cool the exhaust steam with considerable internal energy and calorific value to condensate and dissipate the heat released during the cooling process of the exhaust steam (referred to as "exhaust steam waste heat" in the industry) into the atmosphere. Therefore, there has always been a problem that this part of the energy has not been effectively utilized and has been wasted. Summary of the Invention

[0010] The present invention is completed in view of the above situation, and its purpose is to provide a new type of cooling system for combined heat and cold supply, which can maximize the recovery of the exhaust steam waste heat in the exhaust steam while realizing the exhaust steam cooling function of the existing cooling system in the power generation system, and achieve the full utilization of energy.

[0011] A new type of cooling system for combined heat and cold supply according to one aspect of the present invention is used to cool the exhaust steam generated by a steam turbine in a power generation system including a boiler and a steam turbine. It is characterized by including: a steam pressurization device for pressurizing the exhaust steam; and a heat exchanger for exchanging heat between the pressurized exhaust steam by the steam pressurization device and an external refrigerant, so that the exhaust steam is cooled to generate steam condensate, which is then provided to the boiler as boiler circulating water.

[0012] In the above new type of cooling system for combined heat and cold supply, it further includes an air-cooling subsystem or a water-cooling subsystem connected in parallel with the steam pressurization device and the heat exchanger. The air-cooling subsystem and the water-cooling subsystem cool a part of the exhaust steam and are provided to the boiler as a part of the boiler circulating water.

[0013] In the above new type of cooling system for combined heat and cold supply, the external refrigerant is the return water of an urban heating system.

[0014] In the above new type of cooling system for combined heat and cold supply, the steam pressurization device includes a booster and a driving unit for driving the booster to pressurize the exhaust steam.

[0015] In the above new type of cooling system for combined heat and cold supply, the driving unit is an electric motor, and the electric energy for driving the electric motor comes from the power generation system.

[0016] In the above-mentioned novel cooling system for combined cooling, heating and power supply, the driving unit is a steam turbine driven by steam extracted from the steam path in the power generation system.

[0017] In the above-mentioned novel cooling system for combined cooling, heating and power supply, the driving unit is a motor and a steam turbine connected in series. The electric energy for driving the motor comes from the power generation system, and the steam turbine is driven by steam extracted from the steam path in the power generation system.

[0018] In the above-mentioned novel cooling system for combined cooling, heating and power supply, the power generation system includes a plurality of power generation subsystems. Each power generation subsystem includes a set of the boiler and the steam turbine. The electric energy for driving the motor comes from the power generation subsystem where the motor is located or other power generation subsystems.

[0019] In the above-mentioned novel cooling system for combined cooling, heating and power supply, the power generation system includes a plurality of power generation subsystems. Each power generation subsystem includes a set of the boiler and the steam turbine. The steam turbine is driven by steam extracted from the steam path in the power generation subsystem where the steam turbine is located or other power generation subsystems.

[0020] According to another aspect of the novel cooling system for combined cooling, heating and power supply of the present invention, which is used to cool the exhaust steam generated by the steam turbine in a power generation system including a boiler and a steam turbine, it is characterized by including: a steam boosting device for boosting the exhaust steam; and a heat pump chiller driven by the exhaust steam boosted by the steam boosting device to cool an external refrigerant. At the same time, the exhaust steam is cooled to generate steam condensate, which is then provided to the boiler as boiler circulating water.

[0021] In the above-mentioned novel cooling system for combined cooling, heating and power supply, it further includes an air-cooling subsystem or a water-cooling subsystem connected in parallel with the steam boosting device and the heat pump chiller. The air-cooling subsystem and the water-cooling subsystem cool a part of the exhaust steam, which is then provided to the boiler as a part of the boiler circulating water.

[0022] In the above-mentioned novel cooling system for combined cooling, heating and power supply, the external refrigerant is refrigeration return water.

[0023] By adopting the present invention, while realizing the function of cooling the exhaust steam of the existing cooling system in the power generation system, the exhaust steam waste heat in the exhaust steam can be recovered to the greatest extent, achieving the full utilization of energy.

[0024] The specific content of the present invention will be described below in conjunction with the drawings and specific embodiments. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of a prior art water cooling system.

[0026] Figure 2 It is a schematic diagram of a prior art air cooling system.

[0027] Figure 3 It is a schematic diagram illustrating the defects in the prior art.

[0028] Figure 4 It is a schematic diagram of the exhaust steam cooling system of the present utility model. Detailed implementation manners

[0029] The present utility model will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present utility model are shown in the drawings, it should be understood that the present utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present utility model. It should be understood that the drawings and embodiments of the present utility model are only for exemplary purposes and are not used to limit the protection scope of the present utility model.

[0030] Figure 1 It is a schematic diagram of a prior art water cooling system.

[0031] This water cooling system is used to cool the exhaust steam in the power generation system. Here, the power generation system includes: a boiler 11 that operates to generate steam; a steam turbine 12 that is connected to the boiler 11 and converts the potential energy of the steam generated by the boiler 11 into the kinetic energy of the rotor; and a generator 13 that is connected to the steam turbine 12 and converts the kinetic energy of the rotor into electrical energy and outputs it to the power grid. Here, although not specifically illustrated, the steam turbine 12 may include a high-pressure cylinder 121, an intermediate-pressure cylinder 122, and a low-pressure cylinder 123, which are arranged in sequence from upstream to downstream in the steam flow path in the power generation system.

[0032] In the prior art, the water cooling system 14 is downstream of the steam turbine 12 and cools the exhaust steam generated by the steam turbine, that is, the low-temperature and low-pressure steam generated after the steam turbine does work. The steam condensate generated by cooling through the water cooling system 14 is used as boiler feed water and is cyclically supplied to the boiler 11 through the feed water pump 15. Here, the water cooling system 14 includes: a water-cooled condenser 141 that cools the exhaust steam with cooling water to generate steam condensate; a cooling tower 142 that sprays and dissipates heat from the cooling water that has become hot during the cooling of the exhaust steam in the water-cooled condenser 141 (the waste heat is discharged into the atmosphere), thereby generating low-temperature cooling water; and a low-temperature cooling circulating water pipe 143 and a high-temperature cooling circulating water pipe 144 that circulate between the water-cooled condenser 141 and the cooling tower 142, supply the high-temperature cooling water from the water-cooled condenser 141 to the cooling tower 142, and at the same time supply the low-temperature cooling water from the cooling tower 142 to the water-cooled condenser 141. In addition, a cooling circulating water pump 145 is provided in the system to realize the circulation of the cooling water.

[0033] Figure 2 It is a schematic diagram of the prior art air cooling system.

[0034] This air cooling system is used to cool the exhaust steam in the power generation system. Here, similar to the water cooling system, the power generation system to which the air cooling system is applied also includes a boiler 21, a steam turbine 22, and a generator 23, whose structures and functions are exactly the same as those of the above-mentioned boiler 11, steam turbine 12, and generator 13, and will not be elaborated here.

[0035] In the prior art, the air cooling system 24 is downstream of the steam turbine 22 and cools the exhaust steam generated by the steam turbine. The steam condensate generated by cooling through the air cooling system 24 is used as boiler feed water and is cyclically supplied to the boiler 21 through the feed water pump 25. Here, the air cooling system 24 includes: heat dissipation pipes 241 through which the exhaust steam flows; and heat dissipation fans 242 that blow air towards the heat dissipation pipes 241 to cool the exhaust steam, thereby generating steam condensate.

[0036] Here, the above-described air cooling system 24 belongs to the direct air cooling method. In addition, there is also an air cooling system of the indirect air cooling method. This indirect air cooling system is based on the Figure 1 shown water cooling system 14. Instead of the cooling tower 142, it uses the Figure 2 shown heat dissipation fans 242 to dissipate heat from the high-temperature cooling water from the water-cooled condenser 141 and at the same time supply the cooled low-temperature cooling water to the water-cooled condenser 141.

[0037] Whether it is the water-cooling system or the air-cooling system in the prior art, their functions and purposes are to cool the exhausted steam with still considerable internal energy heat value into condensed water, and dissipate the heat released during the cooling process of the exhausted steam (referred to as "exhaust steam waste heat" in the industry) into the atmosphere. Therefore, this part of the energy is not effectively utilized and is wasted in vain.

[0038] Figure 3 It is a schematic diagram showing the defects in the prior art.

[0039] As Figure 3 shown, the steam condensed water enters the boiler and is heated and vaporized to produce main steam (point A). The temperature and pressure of the main steam at the inlet of the steam turbine are usually relatively high, and its enthalpy value is about 3400 kJ / kg; the steam expands and does work in the steam turbine to complete the energy conversion process from mechanical energy to electrical energy; the exhausted steam (point B) has dropped to a very low temperature and pressure when discharged from the steam turbine, and its enthalpy value is about 2300 kJ / kg; the exhausted steam exchanges heat in the condensing device, discharges the heat into the atmosphere, and the exhausted steam condenses into condensed water. At this time, the enthalpy value of the condensed water (point C) is about 200 kJ / kg. According to the following heat efficiency and waste heat calculation formulas, the thermoelectric conversion efficiency at this time is about 34%, and the preheating waste ratio is about 66%. In other words, only one-third of the input energy obtained by the steam turbine generator set from the boiler is used for power generation, and the remaining two-thirds is dissipated into the atmosphere in vain. Such a large amount of exhaust steam waste heat is not utilized, resulting in a huge waste of energy in the power generation thermal cycle.

[0040] The present utility model precisely solves the problem of wasting energy in vain in the cooling system of the above-mentioned prior art. By doing the opposite of the prior art, the exhausted steam that was originally cooled is pressurized and reused, thereby saving a large amount of energy that was originally wasted in vain by investing a small amount of energy, and realizing the recycling of energy.

[0041] Figure 4 It is a schematic diagram of the cooling system of the present utility model.

[0042] The cooling system of the present utility model is used to cool the exhaust steam in the power generation system while making use of it. Here, the power generation system includes: a boiler 1 that operates to generate steam 10; a steam turbine 2 connected to the boiler 1, which converts the potential energy of the steam generated by the boiler 1 into the kinetic energy of the rotor; and a generator 3 connected to the steam turbine 2, which converts the kinetic energy of the rotor into electrical energy and outputs it to the power grid. Here, not specifically illustrated, the steam turbine 2 may include a high-pressure cylinder 21, an intermediate-pressure cylinder 22, and a low-pressure cylinder 23, each of which contains a rotor with blades (not shown), and the rotors of each cylinder are connected by a shaft (not shown). After the steam pushes the blades to do work and is converted into the kinetic energy of the rotor in the high-pressure cylinder 21, the temperature and pressure decrease, and it is discharged as the exhaust steam of the high-pressure cylinder. The exhaust steam of the high-pressure cylinder is transported back to the boiler 1 through the cold section pipeline of the hot reheat steam for secondary temperature increase (i.e., hot reheat steam), and then, along the hot section pipeline of the hot reheat steam, it is transported to the intermediate-pressure cylinder 22 as the inlet steam of the intermediate-pressure cylinder. After the steam entering the intermediate-pressure cylinder 22 finishes doing work, it is transported to the connecting pipeline between the intermediate-pressure and low-pressure cylinders as the exhaust steam of the intermediate-pressure cylinder and is input into the low-pressure cylinder 23 as the inlet steam of the low-pressure cylinder. The steam does work in the low-pressure cylinder 23, and the kinetic energy of the rotor converted from the steam energy is transmitted to the generator 3 through the shaft connected to the rotor of the low-pressure cylinder 23, thereby being converted into electrical energy and output to the power grid. At the same time, the exhaust steam (exhaust steam) formed after the steam does work in the low-pressure cylinder is cooled by the exhaust steam cooling system 40 of the present utility model described below to form steam condensate 13, and it flows back into the boiler 1 as boiler feed water 14 through the feed water pump 5 for the next cycle. Here, from the operation of the boiler 1 to generate steam until the steam is discharged as steam condensate 13 after doing work in the low-pressure cylinder 23, the steam path in the present utility model is constituted. In addition, although the steam turbine 2 is described by taking it as an example that it includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder, the number of cylinders of the steam turbine 2 can be set according to actual needs. For example, a small steam turbine may also have only one cylinder.

[0043] The novel cooling system of the present utility model includes two subsystems. Among them, the first subsystem is a traditional cooling system 4, as described above, that is, a water cooling system or an air cooling system, which cools the allocated exhaust steam in an existing manner. In addition, the second subsystem is the novel exhaust steam cooling system 40 of the present utility model, which includes two parallel subsystems that cool a part of the exhaust steam according to a certain proportion and simultaneously realize heating or cooling utilization. Specifically, the exhaust steam cooling system 40 of the present utility model includes: a steam pump (steam boosting device) 41, a heating subsystem 51, and a refrigeration subsystem 61. Among them, the steam pump 41 (steam boosting device) boosts and improves the quality of the exhaust steam 11 to become low-quality steam 12, and supplies it to the heating subsystem 51 and the refrigeration subsystem 61 for the above-mentioned heating or cooling. The working principles of the heating subsystem 51 and the refrigeration subsystem 61 will be described below respectively.

[0044] The heating subsystem 51 includes a heat exchanger 52 that exchanges heat between the external refrigerant and the exhausted steam pressurized by the steam pump 41, causing the exhausted steam to be cooled and generate steam condensate, which is then supplied to the boiler 1 as boiler circulating water. Here, as an example of the external refrigerant, return water from the heat network (i.e., return water from the urban heating system) can be cited, but the present utility model is not limited thereto. As long as there is a scenario with a continuous demand for supplying high-temperature refrigerant, the present utility model can be applied. The specific process of the present utility model is as follows: The exhausted steam 11 is pressurized by the steam pump 41 (steam pressurizing device), and after pressurization and quality improvement, it becomes low-quality steam 12. The low-quality steam 12 enters the heat exchanger 52 and exchanges heat with the heat network water. The low-temperature heat network return water 53 (generally at a temperature of 40 - 45°C) is heated to become heat network supply water 54 (generally at a temperature of 80 - 85°C) for external heating. After releasing heat, the low-quality steam 12 becomes condensate 13, and the condensate 13 passes through the feed water pump 5 to become boiler feed water 14, which is then supplied to the boiler 1 as boiler circulating water.

[0045] The refrigeration subsystem 61 includes a heat pump chiller 62 that cools the external refrigerant by being driven by the exhausted steam pressurized by the steam pump 41. At the same time, the exhausted steam is cooled and generates steam condensate, which is then supplied to the boiler 1 as boiler circulating water. Here, as an example of the external refrigerant, return water from refrigeration can be cited, but the present utility model is not limited thereto. As long as there is a scenario with a continuous demand for supplying low-temperature refrigerant, the present utility model can be applied. The specific process of the present utility model is as follows: The exhausted steam 11 is pressurized by the steam pump 41 (steam pressurizing device), and after pressurization and quality improvement, it becomes low-quality steam 12. The low-quality steam 12 with increased pressure and temperature enters the heat pump chiller 62 as the driving steam to operate. The high-temperature refrigeration return water 63 (generally at 12°C) is cooled to become refrigeration supply water 64 (generally at 7°C) for external cooling. After releasing heat, the low-quality steam 12 becomes condensate 13, and the condensate 13 passes through the feed water pump 5 to become boiler feed water 14, which is then supplied to the boiler 1 as boiler circulating water.

[0046] In the heating subsystem, when the external refrigerant is the return water of the urban heating system, usually the temperature of this return water is 45 - 50°C. Therefore, it needs to be heated to 80 - 85°C to meet the standard for use as the supply water of the urban heating system. In the existing system, due to the insufficient enthalpy value of the steam exhausted from the steam turbine, it is usually impossible to achieve a supply water temperature of 80 - 85°C through heat exchange with the return water. However, through the exhausted steam cooling and utilization system of the present utility model, the enthalpy value of the originally wasted exhausted steam is increased, thereby realizing the reuse of waste energy and solving the technical problems existing in the prior art.

[0047] In addition, in the refrigeration subsystem, low-quality steam 12 needs to reach above 80 °C to be used as the driving energy for the refrigeration device 62. In the existing system, the exhaust steam 11 of the steam turbine cannot drive the refrigeration device 62 to produce chilled water or cooling capacity because its own temperature is insufficient, only about 50 °C. However, through the exhaust steam cooling and utilization system of the present utility model, the enthalpy value of the originally wasted exhaust steam is increased, thereby realizing the reuse of waste energy and solving the technical problems existing in the prior art.

[0048] In the specification of this application, the exhaust steam cooling system 40 of the present utility model is introduced in the form of a supplement to the traditional cooling system 4. However, the present utility model is not limited to this. The exhaust steam cooling system 40 of the present utility model can not only be used as a supplement to the traditional cooling system 4, and distribute the exhaust steam for cooling at a certain ratio between it and the traditional cooling system 4; at the same time, the exhaust steam cooling system 40 can completely replace the traditional cooling system 4 and independently realize the cooling and utilization of the exhaust steam. In addition, for the sake of simplicity of description, in the specification of this application, the heating subsystem 51 and the refrigeration subsystem 61 are simultaneously described in the part of the exhaust steam cooling system 40. However, those skilled in the art understand that the heating subsystem 51 and the refrigeration subsystem 61 are two completely independent systems. In the exhaust steam cooling system 40, it can either separately include the heating subsystem 51 to realize external heat supply, or separately include the refrigeration subsystem 61 to realize external cooling supply. It can also, as described in the specification of this application, set the heating subsystem 51 and the refrigeration subsystem 61 in parallel to realize simultaneous heat supply and cooling.

[0049] Specifically, there are various operating modes for the refrigeration system of the present utility model. For example, assuming the exhaust steam flow rate Q of the steam turbine, where Q1 enters the traditional cooling system, and the condensation latent heat corresponding to Q1 is released into the atmosphere without being utilized; Q2 enters the heating subsystem, and the condensation latent heat corresponding to Q2 is exchanged into the heating water for utilization; Q3 enters the refrigeration subsystem, and the condensation latent heat corresponding to Q3 is exchanged into the chilled water for utilization. The various operating modes in the present utility model include: Q = Q1 + Q2 + Q3 (all three systems are operating), Q = Q1 + Q2 (no cooling), Q = Q1 + Q3 (no heating), Q = Q2 + Q3 (combined heating and cooling, the flow rate that is only cooled without being utilized is 0), Q = Q1 (only cooling without heating / cooling), Q = Q2 (full heating), Q = Q3 (full cooling).

[0050] In addition, in the second subsystem, as Figure 4 shown, the steam pump 41 includes a booster 411 and a drive unit 412. The drive unit 412 is used to drive the booster 411 to boost the exhaust steam.

[0051] Here, the booster 411 is used to boost the pressure of the steam, and various types such as piston compressors, rotary compressors, screw compressors, centrifugal compressors, axial compressors, mixed-flow compressors, and jet compressors can be adopted.

[0052] In addition, in order to make the booster 411 work, it is necessary to connect and drive the unit 412 thereto. As an example of the drive unit 412, an electric drive method driven by an electric motor, a steam drive method driven by a driving steam turbine, and a steam-electric dual-drive method driven by both a driving steam turbine and an electric motor can be adopted. Among them, in the steam-electric dual-drive method, the driving steam turbine and the electric motor are connected in series, so as to output the power of both to the booster. The specific connection method belongs to the well-known method of those skilled in the art, and the illustration and detailed description thereof are omitted here. In addition, both the electric motor and the driving steam turbine as the drive unit are related devices sold on the market. In addition, regardless of whether an electric motor, a driving steam turbine, or a steam-electric dual-drive is adopted as the drive unit, the electric energy and steam as the power source thereof can come from the same generator set in the power generation system or from other generator sets. Specifically, as the steam source of the driving steam turbine, it is preferably from the steam path of the same generator set. When there are multiple parallel generator sets in the power generation system, it can also come from the steam path of other generator sets; similarly, as the power supply of the electric motor, it is preferably from the generator of the same generator set. When there are multiple parallel generator sets in the power generation system, it can also come from the generators of other generator sets.

[0053] Embodiment 1

[0054] Above, the principle of the present utility model has been described. Next, the energy-saving effect achieved by the heating subsystem of the present utility model will be described through specific Embodiment 1. Assume a system with an inlet steam of 100 t / h and an exhaust steam of 100 t / h (in order to simplify the description process, there is no extraction steam regenerative system). For the utilization of this 100 t / h of exhaust steam, the following discussion and comparison are carried out for the four working conditions where the second subsystem utilizes 0%, 33%, 67%, and 100% of the exhaust steam respectively.

[0055]

[0056] As can be seen from the above table, as the proportion of exhaust steam utilization in the second subsystem increases, the heating power rises from 0 kW to 70555.4 kW, the heat consumption of the unit drops from 13121.7 kJ / kWh to 3986.8 kJ / kWh, the coal consumption for power generation drops from 446.3 g / kWh to 135.6 g / kWh, and the thermal efficiency of power generation rises from 27.44% to 90.30%.

[0057] Embodiment 2

[0058] The following takes the specific Embodiment 2 to illustrate the energy-saving effect achieved by the refrigeration subsystem of the present utility model. For the steam-driven heat pump chiller 62, steam reaching the driving steam parameters must be input into the system for normal operation to provide the energy source required for the refrigeration cycle. Taking the performance parameters of a certain type of hot water single-effect absorption chiller as an example, to produce a refrigerating capacity of 2.4 MW, 5 t / h of driving steam at 50 kPa.a needs to be input. The energy provided by this part of the driving steam is 3 MW. That is, when directly using external driving steam with higher parameters to input into the heat pump refrigeration cycle, the COP of this process route is only 0.8. By using the cooling system of the present utility model, under the same refrigerating capacity and driving steam demand, to boost the pressure of 5 t / h of exhaust steam from 10 kPa.a to 50 kPa.a, 0.5 MW of electric energy needs to be input. That is to say, only 0.5 MW of high-quality energy needs to be provided to produce a refrigerating capacity of 2.4 MW, and the COP of this process route is 4.8, significantly improving the energy efficiency of the refrigeration cycle.

[0059] Therefore, by adopting the cooling system of the present utility model, the coal consumption for power generation is significantly reduced, and the thermal efficiency and profitability of the unit are greatly improved, meeting the current national call for developing new quality productivity.

[0060] The above description is only the preferred embodiment of the present utility model and the explanation of the applied technical principles. Those skilled in the art should understand that the disclosed scope in the present utility model is not limited to the technical solution formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the technical solution formed by mutually replacing the above features with the (but not limited to) technical features with similar functions disclosed in the present utility model.

Claims

1. A new cooling system for combined cooling and heating, used for cooling the exhaust steam generated by the steam turbine in a power generation system including a boiler and a steam turbine, characterized in that: include: A steam booster device for boosting the exhaust steam; as well as The heat exchanger exchanges heat with the exhaust steam pressurized by the steam supercharging device through an external refrigerant, so that the exhaust steam is cooled to generate steam condensate, which is then provided to the boiler as boiler circulating water.

2. The novel cooling system for combined cooling and heating according to claim 1, characterized in that: It also includes an air cooling subsystem or a water cooling subsystem connected in parallel with the steam booster and the heat exchanger. The air cooling subsystem and the water cooling subsystem cool a portion of the exhaust steam, and the exhaust steam is provided to the boiler as a portion of the boiler circulating water.

3. The novel cooling system for combined cooling and heating according to claim 1, characterized in that: The external refrigerant is return water from a town heating system.

4. The novel cooling system for combined cooling and heating according to claim 1 is characterized in that: The steam boosting device includes a booster and a driving unit, and the driving unit is used to drive the booster to boost the exhaust steam.

5. The novel cooling system for combined cooling and heating as claimed in claim 4, characterized in that: The driving unit is an electric motor, and the electric energy for driving the electric motor comes from the power generation system.

6. The novel cooling system for combined cooling and heating as claimed in claim 4, characterized in that: The drive unit is a traction steam turbine which is driven by steam extracted from a steam path in the power generation system.

7. The novel cooling system for combined cooling and heating as claimed in claim 4, characterized in that: The driving unit is a motor and a steam turbine connected in series. The electric energy for driving the electric motor comes from the power generation system. The traction steam turbine is driven by steam extracted from a steam path in the power generation system.

8. The novel cooling system for combined cooling and heating as claimed in claim 5 or 7, characterized in that: The power generation system includes a plurality of power generation subsystems, each of which includes a set of the boiler and the steam turbine. The electric energy for driving the electric motor comes from the power generation subsystem where the electric motor is located, or other power generation subsystems.

9. The novel cooling system for combined cooling and heating according to claim 6 or 7, characterized in that: The power generation system includes a plurality of power generation subsystems, each of which includes a set of the boiler and the steam turbine. The traction steam turbine is driven by steam extracted from a steam path in the power generation subsystem in which the traction steam turbine is located or in another of the power generation subsystems.

10. A new cooling system for combined cooling and heating, used for cooling the exhaust steam generated by the steam turbine in a power generation system including a boiler and a steam turbine, characterized in that: include: A steam booster device for boosting the exhaust steam; as well as The heat pump refrigerator is driven by the exhaust steam pressurized by the steam supercharging device to cool the external refrigerant. At the same time, the exhaust steam is cooled to generate steam condensate, which is then provided to the boiler as boiler circulating water.

11. The novel cooling system for combined cooling and heating according to claim 10, characterized in that: It also includes an air cooling subsystem or a water cooling subsystem connected in parallel with the steam booster device and the heat pump refrigerator. The air cooling subsystem and the water cooling subsystem cool a portion of the exhaust steam, and the exhaust steam is provided to the boiler as a portion of the boiler circulating water.

12. The novel cooling system for combined cooling and heating according to claim 10, characterized in that: The external refrigerant is refrigeration return water.

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