CN220621981U - Low-temperature saturated steam waste heat utilization power generation system suitable for food processing industry - Google Patents

Abstract

The utility model relates to a low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry, which comprises a heat source input system and a power generation circulation system, wherein the heat source input system comprises a heat source and an evaporator, and the heat source is connected with the evaporator through a heat source input pipeline; the power generation circulation system comprises an evaporator, a generator, an air-cooled condenser, a working medium pump, a liquid storage tank, a heat regenerator, a preheater and a grid-connected inverter, wherein the working medium and a heat source are used for exchanging heat, and the generator is used for generating power. According to the utility model, the waste heat of the directly discharged saturated steam in the food processing industry is recovered, the heat energy is converted into mechanical energy and then into electric energy, the recovery of the heat energy is realized, and the greenhouse benefit risk brought by the direct discharge is reduced.

Description

Suitable for low-temperature saturated steam waste heat utilization power generation system in the food processing industry

Technical field

The utility model belongs to the technical field of waste heat recovery and energy saving in the food processing industry. Specifically refers to a system based on the principle of the Organic Rankine Cycle (ORC) plus magnetic levitation high-speed permanent magnet radial turbine expansion power generation technology, which uses the low-temperature saturated steam at the tail end of the production process system to generate waste heat.

Background technique

There has long been considerable waste and loss in the use of energy in our country. According to statistics, the energy utilization rate is less than 40%, which is 10-20 percentage points lower than that in developed countries.

According to the temperature of waste heat, it can be divided into the following three types: low temperature waste heat, medium temperature waste heat and high temperature waste heat. Usually, waste heat with a temperature lower than 220°C is called low-temperature waste heat; waste heat with a temperature between 220 and 650°C is called medium-temperature waste heat; waste heat with a temperature higher than 650°C is called high-temperature waste heat. The low-temperature waste heat generated in the industrial production process accounts for more than 50%, but the utilization rate is very low.

ORC is a proven power generation system that can convert low-grade thermal energy into electrical energy. This system uses an evaporator to exchange heat between low-grade thermal energy and organic working fluid. The organic working fluid absorbs heat and changes from liquid to gaseous state. High-pressure The organic working fluid vapor drives the turbine expander to do work, converting thermal energy into mechanical energy, and drives the generator to rotate to generate electrical energy. After the organic working fluid in the vapor state releases energy in the expander, it enters the condenser from the outlet of the expander and is cooled into a liquid. It is pressurized by the working fluid pump and then enters the evaporator again to start a new cycle.

The efficient utilization of low-grade thermal energy is an important way to solve energy problems. Low-grade thermal energy includes industrial low-temperature waste heat and geothermal energy, solar energy, biomass energy, etc. in the field of new energy. The utilization of low-grade thermal energy can not only improve energy utilization and promote energy conservation and emission reduction, but also optimize the energy supply structure, which has important practical significance.

In the food processing industry, traditional production process systems require saturated steam at 185°C to cook noodle cakes. The main purpose of cooking is to promote the ɑification of starch. Saturated steam is directly discharged into the atmosphere after passing through the steamer. In order to avoid waste of energy and impact on the environment, a solution for low-temperature saturated steam needs to be provided.

Utility model content

The purpose of this utility model is to provide a low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry to avoid direct discharge of low-temperature saturated steam in the food processing industry into the atmosphere, as well as waste of energy and impact on the environment.

Technical solution of the utility model:

A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry, including: a heat source input system and a power generation cycle system. The heat source input system includes a heat source and an evaporator. The heat source is connected to the hot side inlet of the evaporator through a heat source input pipeline. Connection, the hot side outlet of the evaporator is connected to the vacuum filter inlet, the vacuum filter outlet is connected to the hot side inlet of the preheater, and the hot side outlet of the preheater discharges softened water;

The power generation cycle system includes an evaporator, a generator, an air-cooled condenser, a working fluid pump, a liquid storage tank, a regenerator, a preheater, and a grid-connected inverter. The water outlet of the liquid storage tank is connected to the industrial plant through pipelines. The other end of the working medium pump is connected to the return port of the liquid storage tank through a pipeline. The pipeline between the working medium pump and the return port of the liquid storage tank is connected to the cold side inlet of the regenerator through the pipeline. The regenerator The cold side outlet is connected to the cold side inlet of the preheater, the cold side outlet of the preheater is connected to the cold side inlet of the evaporator, the cold side outlet of the evaporator is connected to the generator inlet, and the generator outlet is connected to the hot side inlet of the regenerator. The hot side outlet of the regenerator is connected to the hot side inlet of the air condenser, the hot side outlet of the air condenser is connected to the working fluid pump, the electricity generated by the generator is integrated into the grid through the grid-connected inverter, and the cold side outlet of the evaporator is connected to the power generation The pipeline between the machines is connected to the hot side inlet of the air-cooled condenser through a branch line.

Beneficial effects of this utility model:

1. This utility model is aimed at recovering the waste heat of direct discharge of saturated steam in the food processing industry. It converts thermal energy into mechanical energy and then into electrical energy to realize the recovery of heat energy and at the same time reduce the greenhouse efficiency risks caused by direct discharge.

2. This utility model can realize efficient utilization of waste heat from saturated steam in the existing food processing industry without reducing the taste of waste heat energy, which can not only save energy and reduce emissions, but also reduce costs for enterprises.

3. The utility model uses a magnetic levitation expansion generator in the power generation cycle system. Most of the existing traditional expanders are screw expander generators. The main disadvantages of screw expander generators are:

①. The operation noise is relatively large. Generally, noise elimination and noise reduction equipment needs to be installed.

②. The power consumption is relatively high.

③. After long-term operation, the screw clearance will become larger, and the cost of regular repair or replacement will be high.

The magnetic levitation high-speed permanent magnet radial turbine expansion power generation is:

① , high thermal efficiency;

② The equipment is compact and the entire system is easy to integrate and skid;

③, low operating noise;

④ The bearings operate in a non-contact manner, with low energy consumption, no lubrication system, no seals, lifetime maintenance-free components, low cost, and real-time detection of rotor imbalance.

⑤. Long service life, the service life of the generator set can reach 10-15 years.

4. Conventional condensers usually use water-cooled condensers, but in many cases there is no cold water source for cooling in on-site usage, and the cold water source also has the risk of sewage discharge, which increases operation and maintenance costs and requires investment in equipment. Therefore, this is practical The condenser in the new system uses an air-cooled condenser, which directly uses air to cool the working fluid.

5. This utility model's ORC magnetic levitation power generation system suitable for low-temperature saturated steam waste heat utilization was originally intended to be used in the north and fully meets the design requirements in winter, spring and autumn. However, since the summer temperature is above 30°C, air cooling cannot The mass is completely condensed, which will lead to a reduction in the power generation efficiency of the system. Since the maximum rated input of the system is 5t/h of saturated steam, but the actual rated consumption of the unit is 3.5t/h, when the power generation efficiency decreases in summer, the power generation power can be adjusted by increasing the heat source flow.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description These are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without exerting creative efforts.

Figure 1 is a system flow chart of this application.

Figure 2 is a process flow diagram of the present application.

Reference signs:

Heat source 1; evaporator 2; vacuum filter 3; air-cooled condenser 4; working fluid pump 5; liquid storage tank 6; regenerator 7; preheater 8; grid-connected inverter 9; second valve 10; heat source Input pipeline 11; first valve 12; third valve 13; fourth valve 14; fifth valve 15; sixth valve 16; seventh valve 17; eighth valve 18; generator 19.

Detailed ways

The utility model provides an ORC magnetic levitation power generation system suitable for low-temperature saturated steam waste heat utilization in the food processing industry. It belongs to the field of waste heat recovery and energy-saving technology in the food processing industry, and specifically refers to a power generation system based on the principle of Organic Rankine Cycle (ORC). Maglev high-speed permanent magnet radial turbine expansion power generation technology uses low-temperature saturated steam at the tail end of the production process system to generate waste heat. The system consists of two parts. One is the saturated steam discharged from the user's process system as a heat source input into the system, and the other is the power generation cycle system. In the food processing industry, there is a large amount of saturated steam that has not been fully utilized in the production process system. The conventional treatment method is to directly discharge it into the atmosphere, which causes energy waste and generates a greenhouse effect. By introducing this part of saturated steam into the power generation cycle system, the generated electricity can be used spontaneously in the plant, which can not only achieve the effect of energy saving and emission reduction, but also bring high economic benefits every year. At the same time, it is condensed The high-temperature water can also be used to heat factories. The utility model fully utilizes the waste heat resources of the process system in the food processing industry.

This application is described in detail below:

A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry, including a heat source input system (saturated steam discharged from the user's process system is used as a heat source input system) and a power generation cycle system. The heat source input system includes a heat source 1 and an evaporator 2. The heat source 1 is connected to the hot side inlet of the evaporator 2 through the heat source input pipeline 11. The hot side outlet of the evaporator 2 is connected to the vacuum filter 3. The vacuum filter The outlet 3 is connected to the hot side inlet of the preheater, and the hot side outlet of the preheater discharges softened water.

The power generation cycle system includes an evaporator 2, a generator 19, an air-cooled condenser 4 (the air-cooled condenser uses air as the cold source), a working fluid pump 5, a liquid storage tank 6, a regenerator 7, a preheater 8, and Grid inverter 9. The liquid storage tank 6 has three ports, namely a water inlet, a water outlet and a water return port. The water inlet of the liquid storage tank is used to add working fluids. A fifth valve is installed on the water inlet pipeline, and the water outlet is used to add working fluids through the working fluid pump. The working fluid is pumped into the system, and the water return port is used to pump the working fluid back into the liquid storage tank when the system is not working. The water outlet of the liquid storage tank is connected to the working fluid pump 5 through a pipeline (a fourth valve is installed on the pipeline), and the other end of the working fluid pump 5 is connected to the water return port of the liquid storage tank through a pipeline (a third valve is installed on the pipeline). connection, the pipeline between the working medium pump 5 and the return port of the liquid storage tank 6 is connected to the cold side inlet of the regenerator 7 through the pipeline (the sixth valve is installed on the pipeline), and the cold side outlet of the regenerator 7 is connected to the preheater. The cold side inlet of heater 8 is connected, the cold side outlet of preheater 8 is connected to the inlet of evaporator 2, and the outlet of evaporator 2 is connected to the generator inlet through a pipeline (a seventh valve is installed on the pipeline). Generator 19 The outlet is connected to the hot side inlet of the regenerator 7, the hot side outlet of the regenerator 7 is connected to the 4-side inlet of the air condenser, the 4-side outlet of the air condenser is connected to the working fluid pump, and the electricity generated by the generator 19 is reversed through the grid connection. Transformer 9 is integrated into the power grid, and the pipeline between the cold side outlet of evaporator 2 and the generator is connected to the hot side inlet of air-cooled condenser 4 through a branch (an eighth valve is installed on the pipeline). There is also another branch on the heat source input pipeline 11, and a second valve 10 is installed on the branch. The second valve 10 is in a normally closed state. When the power generation system exceeds the rated operating condition, the second valve 10 is opened to remove the excess heat source. Perform direct emptying. In order to avoid damage caused by over-rated operation of the magnetic levitation expansion generator.

Further, the heat source input by the heat source system is saturated steam containing starch between 100-110°C. The saturated steam as a heat source exchanges heat with the working fluid in the evaporator and turns into condensed water. Since the saturated steam contains starch, in order to ensure the long-term and stable operation of the system, and the condensed water can be recycled in the system, Therefore, a corresponding vacuum filter 3 is added to the system.

Since the saturated steam in the production process only has a slight positive pressure, the original treatment method is to directly connect to the atmosphere through pipelines and evacuate through the pressure difference. Now it is necessary to collect the saturated steam discharged from the production lines in the entire factory and then transport it as input to the waste heat In the evaporator in the power generation system, and the evaporator itself has pressure resistance, so in order to successfully introduce saturated steam into the evaporator, a vacuum filter 3 needs to be added to the system.

Furthermore, the evaporator 2, air-cooled condenser 4, magnetic levitation expansion generator 19, and working fluid pump 5 are connected through pipelines, and the working fluid in the pipelines circulates in the system. The working fluids are low-boiling organic working fluids R245fa and R134a, which are mixed in a ratio of 8:2.

Heat exchange is completed in the evaporator between the heat source input system and the circulating working fluid in the power generation cycle system; the high-pressure organic working fluid vapor drives the turbine expander to perform work, converting thermal energy into mechanical energy and driving the generator to rotate. The power generation cycle system device includes an evaporator 2 preheater, a regenerator, a condenser, a magnetic levitation expansion generator, etc. The further power generation cycle system is equipped with a regenerator. The calculated pressure loss design value of the regenerator is 20kPa, and the energy loss caused is about 20.53kW; the energy recovered by the regenerator is about 220kW. Considering that the system efficiency is about 10.65%, the recovered heat is converted into usable work of about 20.53kW. 23.43kW. The difference between the two is about 2.9kW, which is the increased power generation of the system.

Variable frequency working fluid pump 5 for pressurizing the working fluid; air-cooled condenser 4 for condensing the working fluid from gaseous to liquid state; magnetic levitation expansion generator 19 for converting thermal energy into electrical energy; used to increase the overall system heat Regenerator 7 and preheater 8 with high cycle efficiency.

The evaporator 2 uses a brazed heat exchanger, and the evaporator uses at least one heat exchanger. The heat exchanger forms include tubular, brazed, and fully welded. It is best to connect three units in parallel, two for use and one for backup.

All pipes in the power generation system of this application should be insulated.

The working medium pump 5 adopts a variable frequency working medium pump, which changes the frequency according to the flow rate change of the heat source. Furthermore, a variable frequency working fluid pump is used to control the evaporation temperature of the evaporator by adjusting the flow rate of the working fluid.

Optimally, there are three evaporators 2. The heat source in the heat source input system is the saturated steam discharged from the system during process production. Multiple steam discharge straight pipes converge to the heat source input pipe 11. The heat source input pipe Road 11 leads to three branches (the first valves 12 are installed on the branches) and are connected to the hot side inlet of the evaporator 2. The first valves 12 of two evaporators are in a normally open state, and the first valve 12 of the third evaporator 2 is in a normally open state. 12 is normally closed. The saturated steam discharged from the user's production process needs to be centrally introduced into the evaporator. Since there are multiple production process lines in the factory, each production line is equipped with a separate straight steam discharge pipe. Therefore, the heat source input system needs to add the original steam discharge straight pipe to the tee, so that the steam discharge straight pipes are connected in parallel, and are introduced centrally through the heat source input pipe to the evaporator hot side inlet of the power generation cycle system. Furthermore, each steam discharge straight pipe is equipped with an independent valve. When a certain process production line is shut down for maintenance, the valve in this road is closed to avoid steam backflow.

In order to make the purpose, technical solutions and advantages of the present utility model more clear, the technical solutions in the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the utility model. Obviously, the described embodiments are Some embodiments of the present invention are not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present utility model.

The saturated steam in traditional industrial industries (steel, cement, chemicals, etc.) is mostly saturated steam with a certain high pressure provided by the combined heat and power generation of power plants. The utility model provides an efficient solution for direct discharge of low-temperature saturated steam in the food processing industry.

As shown in Figure 1, this utility model is a low-temperature saturated steam waste heat utilization ORC magnetic levitation power generation system suitable for the food processing industry: it includes a heat source input system and a power generation circulation system. Heat source input system: The saturated steam discharged from the system during process production is gathered into a heat source input pipeline through multiple steam discharge straight pipelines. The heat source input pipeline leads to three branches connected in series with the evaporator. Three evaporators are used in parallel. The first branch valve of two evaporators is in a normally open state, and the first branch valve of the third evaporator is in a normally closed state.

The power generation cycle system includes an evaporator used to change the working fluid from liquid to gaseous state; a variable frequency working fluid pump used to pressurize the working fluid; an air-cooled condenser used to condense the working fluid from gaseous to liquid; Magnetic levitation expansion generator that converts thermal energy into electrical energy; regenerator and preheater used to increase the thermal cycle efficiency of the overall system. Grid-connected inverter for power generation and grid-connected; vacuum filter used to provide vacuum to the system and filter starch-containing saturated steam. The heat source input pipeline also needs to be equipped with a branch with a second valve. The second valve is in a normally closed state. When the power generation system reaches the rated operating condition, the second valve is opened to directly drain the excess heat source. In order to avoid damage caused by over-rated operation of the magnetic levitation expansion generator.

The regenerator is arranged in series between the magnetic levitation expansion generator and the air-cooled condenser, and the cold end outlet of the variable frequency working fluid pump is used as the input of the regenerator; the circulating working fluid flowing out of the working fluid pump returns through the regenerator. After the heater, it flows into the preheater.

This application is equipped with a vacuum filter. Since the heat source is starch-containing saturated steam at 100~110°C with slight positive pressure, the evaporator has pressure resistance. Under normal circumstances, the steam cannot pass smoothly, so it needs to be installed at the hot end of the evaporator. A vacuum filter is introduced at the outlet to ensure that the evaporator outlet is in a slightly negative pressure state, so that steam can pass through the evaporator smoothly. Moreover, this device has a filtering function that can filter the condensed water with starch condensed from the evaporator, and The starch residue in the condensed water is filtered.

work process:

To prepare the system before operation, close the third valve 13 and the fourth valve 14, open the fifth valve 15, and inject organic working fluid into the liquid storage tank 6 through the water inlet.

When the liquid level in the liquid storage tank 6 reaches the value required by the system, the third valve 13 and the fifth valve 15 are closed, and the fourth valve 14 and the sixth valve 16 are opened. The organic medium serves as a carrier for steam heat energy transfer, and is driven by the variable frequency working fluid pump 5 Pump it out from the liquid storage tank 6 and slowly increase the speed of the working fluid pump. Close the second valve 10, open the first valve 12, and at the same time open the vacuum pump in the vacuum filter 3 to introduce starch-containing saturated steam at 100~110°C into the evaporator. In the evaporator 2, heat exchange occurs between the saturated steam and the organic working fluid, and the temperature, pressure and other parameters before the evaporator and after the air-cooled condenser are recorded at the same time. Before operation, open the eighth valve in front of the maglev expansion generator and close the seventh valve 17. When the pressure difference reaches a certain value, close the eighth valve 18 and open the seventh valve in front of the maglev expansion generator to transfer the working fluid. The high-pressure steam generated by absorbing heat in the evaporator is transported to the magnetic levitation expansion generator, and does work through radial turbine expansion, thereby converting heat energy into electrical energy output; after completing the above process, it will be discharged at the outlet of the expansion machine generator After the energy is released, the low-pressure gas-liquid mixed working medium is sequentially transported to the air-cooled condenser of the regenerator and condensed into a liquid.

Under the action of the working fluid circulation pump, the liquid working fluid is pressurized to have a higher evaporation temperature. It enters the evaporator in a liquid state, absorbs the energy generated by the high-temperature heat source, and then forms high-pressure steam and enters the expander. Perform work; through the infinite cycle of the above process, the process of converting waste heat resources into high-quality electrical energy is realized.

When the system stops running, close the fourth valve and the sixth valve on the pipeline, open the third valve, and re-inject the working fluid into the liquid storage tank.

As shown in Figure 2, the heat source first enters the evaporator and undergoes heat exchange to form condensed water. It enters the vacuum filter and then enters the preheater, finally forming softened water at 85-90°C. The softened water from the preheater is used to heat the factory through the plate heat exchange unit, which can meet the heating needs of the 3000㎡ factory. The final circulating water whose temperature is reduced to 50-60℃ will be returned to the steam boiler to reach the entire system. Closed-loop and efficient utilization of steam. The heat delivery pipeline is used to send the waste heat carrier to the heat users, so that the heat users can utilize the waste heat carrier. After use, the temperature of the waste heat carrier drops and is sent back to the factory under the action of the return pipeline, so that the waste heat carrier can Forming a complete cycle, full utilization of waste heat from the factory is achieved.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, but not to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it still The technical solutions described in the foregoing embodiments can be modified, or some of the technical features can be equivalently replaced; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and spirit of the technical solutions of the various embodiments of the present invention. scope.

Claims (7)

1. A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry, which is characterized by: including: a heat source input system and a power generation cycle system. The heat source input system includes a heat source and an evaporator. The heat source is input through a heat source pipeline. It is connected to the hot side inlet of the evaporator, the hot side outlet of the evaporator is connected to the vacuum filter inlet, the vacuum filter outlet is connected to the hot side inlet of the preheater, and the hot side outlet of the preheater discharges softened water; The power generation cycle system includes an evaporator, a generator, an air-cooled condenser, a working medium pump, a liquid storage tank, a regenerator, a preheater, and a grid-connected inverter. The water outlet of the liquid storage tank is connected to the industrial plant through pipelines. The other end of the working medium pump is connected to the return port of the liquid storage tank through a pipeline. The pipeline between the working medium pump and the return port of the liquid storage tank is connected to the cold side inlet of the regenerator through the pipeline. The regenerator The cold side outlet is connected to the cold side inlet of the preheater, the cold side outlet of the preheater is connected to the cold side inlet of the evaporator, the cold side outlet of the evaporator is connected to the generator inlet, and the generator outlet is connected to the hot side inlet of the regenerator. The hot side outlet of the regenerator is connected to the hot side inlet of the air condenser, the hot side outlet of the air condenser is connected to the working fluid pump, the electricity generated by the generator is integrated into the grid through the grid-connected inverter, and the cold side outlet of the evaporator is connected to the power generation The pipeline between the machines is connected to the hot side inlet of the air-cooled condenser through a branch line. 2. A power generation system suitable for low-temperature saturated steam waste heat utilization in the food processing industry according to claim 1, characterized in that: the evaporator adopts at least one heat exchanger, and the evaporator is a tubular heat exchanger or a solder. Welded heat exchanger or fully welded heat exchanger. 3. A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry according to claim 1, characterized in that: the outside of the pipelines of the power generation system is covered with an insulation layer. 4. A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry according to claim 1, characterized in that: the working fluid pump adopts a variable frequency working fluid pump. 5. A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry according to claim 1, characterized in that: there are three evaporators, and the heat source in the heat source input system is system emissions from process production. The saturated steam coming out is gathered into the heat source input pipeline by multiple steam discharge straight pipelines. The heat source input pipeline leads to three branches connected to the hot side inlet of the evaporator. The first valves of two evaporators are in a normally open state. The first valve of the third evaporator is in a normally closed state. 6. A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry according to claim 1, characterized in that: there is another branch on the heat source input pipeline, and a second valve is installed on the branch. The second valve is in a normally closed state. When the power generation system reaches the rated operating condition, the second valve is opened to directly drain the excess heat source. 7. A low-temperature saturated steam waste heat utilization power generation system suitable for the food processing industry according to claim 1, characterized in that: the generator is a magnetic levitation expansion generator.