Exhaust steam waste heat utilization system of condensing steam turbine

Abstract

The utility model discloses an exhaust steam waste heat utilization system of a condensing steam turbine, which efficiently utilizes exhaust steam latent heat of the condensing steam turbine and avoids heat waste. Comprising a boiler, a steam turbine, a condenser, a pump and a preheater, the condenser and the preheater are each provided with a heating section and a heat absorption section, the outlet end of the boiler is sequentially connected with the steam turbine, the heating section of the condenser, the pump, the heat absorption section of the preheater and the inlet end of the boiler, and the condensing steam turbine Rankine cycle system is formed. A cycle working medium of the condensing steam turbine Rankine cycle system is water; the outlet end of the heat absorption section of the condenser is sequentially connected with the inlet ends of the compressor, the heating section of the preheater, the expansion valve and the heat absorption section of the condenser to form a heat pump circulating system, and the circulating working medium of the heat pump circulating system is an organic working medium.

Description

Technical Field

[0001] This utility model relates to the field of low-temperature waste heat utilization technology, and in particular to a condensing steam turbine exhaust waste heat utilization system. Background Technology

[0002] Against the backdrop of national advocacy for low-carbon, environmentally friendly, energy-saving, and emission-reducing development, an increasing amount of low-temperature waste heat from industrial waste gases, liquids, and materials is being effectively utilized. In the Rankine cycle of condensing steam turbines, such as... Figure 1 As shown, the exhaust steam from the turbine is cooled to a liquid state by circulating cooling water. The latent heat released during the transition from gaseous to liquid state is carried away by the circulating cooling water and released into the environment. However, the exhaust steam temperature of medium and small-sized units is generally above 60℃, and the temperature of the exhaust steam after cooling to a liquid state is generally around 35℃. This means that all the latent heat from the turbine exhaust steam transitioning from gaseous to liquid state is released into the environment, resulting in a complete waste of heat.

[0003] Therefore, the utility model described in this article aims to efficiently utilize this portion of heat, thereby helping my country achieve its strategic development goal of "carbon peaking and carbon neutrality" as soon as possible. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a condensing steam turbine exhaust waste heat utilization system that efficiently utilizes the latent heat of condensing steam turbine exhaust and avoids heat waste.

[0005] The purpose of this utility model is achieved as follows:

[0006] A condensing steam turbine exhaust waste heat utilization system includes a condensing steam turbine Rankine cycle system, comprising a boiler, a steam turbine, a condenser, a pump, and a preheater. Both the condenser and the preheater have heating sections and heat absorption sections.

[0007] The boiler outlet is connected in sequence to the steam turbine, condenser heating section, pump, preheater heat absorption section, and boiler inlet, forming a condensing steam turbine Rankine cycle system. The circulating working fluid of the condensing steam turbine Rankine cycle system is water.

[0008] It also includes a compressor and an expansion valve. The outlet end of the condenser heat absorption section is connected in sequence to the compressor, the preheater heating section, the expansion valve, and the inlet end of the condenser heat absorption section, forming a heat pump circulation system. The circulating working fluid of the heat pump circulation system is an organic working fluid.

[0009] Preferably, the working fluid of the heat pump cycle system is R245fa.

[0010] Due to the adoption of the above technical solution, this utility model has the following beneficial effects:

[0011] 1. The above-mentioned utility model effectively utilizes the latent heat of exhaust steam from condensing steam turbines, avoids heat waste, especially the waste of low-temperature waste heat, and saves resources.

[0012] 2. In the above-mentioned utility model, the high-temperature gas generated by the heat pump system serves as a heat source, and then transfers the heat to the Rankine cycle system of the condensing steam turbine, thus achieving effective heat transfer and utilization.

[0013] 3. In the above-mentioned utility model, the high-temperature gas generated by the heat pump system serves as a heat source, preheating the boiler water supply in the Rankine cycle system of the condensing steam turbine, thereby increasing the water temperature supplied to the boiler, effectively reducing the heat load of the boiler section, saving the gas or coal used to burn the boiler, and effectively conserving mineral resources.

[0014] 4. The above-mentioned utility models accurately respond to the relevant national energy conservation and emission reduction policies, and effectively promote the country's green, efficient, and sustainable high-quality development. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a conventional condensing steam turbine Rankine cycle system.

[0016] Figure 2 This is a schematic diagram of a condensing steam turbine exhaust waste heat utilization system.

[0017] Figure Labels

[0018] Figure 1 In the middle, 1 is a high-temperature gaseous working fluid, 2 is a low-temperature gaseous working fluid, 3 is a low-temperature liquid working fluid, a is a heated liquid working fluid, b is a low-temperature liquid working fluid;

[0019] Figure 2 In the following categories, 1. High-temperature gaseous working fluid, 2. Low-temperature gaseous working fluid, 3. Low-temperature liquid working fluid, and 4. Medium-temperature liquid working fluid, A. Superheated gaseous working fluid, B. High-temperature gaseous working fluid, C. High-pressure liquid working fluid, and D. Low-temperature gaseous working fluid. Detailed Implementation

[0020] See Figure 2 A condensing steam turbine exhaust waste heat utilization system includes a condensing steam turbine Rankine cycle system, comprising a boiler, a steam turbine, a condenser, a pump, and a preheater. The condenser and preheater each have a heating section and an absorption section. The boiler outlet is sequentially connected to the steam turbine, the condenser heating section, the pump, the preheater absorption section, and the boiler inlet, forming the condensing steam turbine Rankine cycle system. The circulating working fluid of the condensing steam turbine Rankine cycle system is water. The system also includes a compressor and an expansion valve. The outlet of the condenser absorption section is sequentially connected to the compressor, the preheater heating section, the expansion valve, and the condenser absorption section inlet, forming a heat pump cycle system. The circulating working fluid of the heat pump cycle system is an organic working fluid.

[0021] In this embodiment, the working fluid of the heat pump cycle system is R245fa.

[0022] The following are methods for utilizing the waste heat from the exhaust steam of condensing steam turbines:

[0023] This waste heat recovery system effectively utilizes the latent heat of exhaust steam from the turbine, preventing energy waste. Details are as follows:

[0024] The left side of the system is a condensing steam turbine Rankine cycle system, which consists of a boiler, turbine, condenser, pump, and preheater. The working fluid is water. Liquid water absorbs heat in the boiler and becomes high-temperature vaporous steam. The high-temperature vaporous steam enters the turbine and does work, driving the turbine. After doing work, the high-temperature vaporous steam becomes low-temperature vaporous steam. The low-temperature vaporous steam enters the condenser for cooling, releasing its latent heat of vaporization and becoming low-temperature liquid water. The low-temperature liquid water is pressurized by the pump and sent to the preheater, where it absorbs heat and becomes medium-temperature liquid water. The medium-temperature liquid water then enters the boiler and absorbs heat again, becoming high-temperature steam. The high-temperature steam continues to circulate in the turbine.

[0025] The right side of the system is a heat pump circulation system, which consists of a condenser, compressor, preheater, and expansion valve. The working fluid is R245fa (an organic working fluid). Low-temperature gaseous R245fa enters the condenser, absorbs heat, and becomes superheated gas. The superheated gaseous R245fa enters the compressor and is compressed into a high-temperature gas. The high-temperature gaseous R245fa enters the preheater, releases heat, and becomes high-pressure liquid R245fa. The high-pressure liquid R245fa enters the expansion valve, expands, and decreases in pressure, becoming low-temperature gas. The low-temperature gas continues to enter the condenser for circulation.

[0026] In the two cycles described above, the exhaust steam from the turbine enters the condenser and releases heat, transferring the heat to the low-temperature gaseous R245fa. The low-temperature gaseous R245fa absorbs heat and becomes superheated. Meanwhile, the high-temperature gaseous R245fa from the compressor outlet enters the preheater and releases heat, transferring the heat to the low-temperature liquid water. The low-temperature liquid water absorbs heat and becomes medium-temperature liquid water. For the entire cycle system, the heat pump system on the right effectively utilizes the latent heat of the turbine exhaust steam and ultimately feeds it back to the turbine's Rankine cycle system.

[0027] according to Figure 2As shown, after setting up the system flow, the boiler, turbine, condenser, pump, and preheater are started sequentially, and the Rankine cycle system of the condensing turbine enters the operating state. When the turbine exhaust steam enters the condenser, the expander and expansion valve are opened to start the heat pump cycle system. During the cycle, the turbine exhaust steam enters the condenser and releases heat, transferring the heat to the low-temperature gaseous R245fa. The low-temperature gaseous R245fa absorbs heat and becomes superheated gas, then enters the compressor to compress and do work, becoming high-temperature gaseous R245fa. The high-temperature gaseous R245fa enters the preheater and releases heat, transferring the heat to the low-temperature liquid water in the Rankine cycle system. The low-temperature liquid water absorbs heat and becomes medium-temperature liquid water, which enters the boiler. For the entire cycle system, the heat pump system on the right effectively utilizes the latent heat of the turbine exhaust steam and ultimately feeds it back to the turbine Rankine cycle system.

[0028] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A condensing steam turbine exhaust waste heat utilization system, comprising a condensing steam turbine Rankine cycle system, characterized in that: It includes a boiler, a steam turbine, a condenser, a pump, and a preheater, wherein the condenser and the preheater each have a heating section and a heat absorption section; The boiler outlet is connected in sequence to the steam turbine, condenser heating section, pump, preheater heat absorption section, and boiler inlet, forming a condensing steam turbine Rankine cycle system. The circulating working fluid of the condensing steam turbine Rankine cycle system is water. It also includes a compressor and an expansion valve. The outlet end of the condenser heat absorption section is connected in sequence to the compressor, the preheater heating section, the expansion valve, and the inlet end of the condenser heat absorption section, forming a heat pump circulation system. The circulating working fluid of the heat pump circulation system is an organic working fluid.

2. The condensing steam turbine exhaust waste heat utilization system according to claim 1, characterized in that: The working fluid in the heat pump cycle system is R245fa.

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