阅读说明：本技术 一种低温余热回收的压缩机节能装置及其方法 (Compressor energy-saving device and method for low-temperature waste heat recovery ) 是由 漆枫林 杨巍 于 2020-12-15 设计创作，主要内容包括：本发明属于压缩机入口降温除湿、压缩机级间冷却、压缩机节能技术领域,尤其是一种低温余热回收的压缩机节能装置及其方法,针对传统的降温除湿装置为电制冷,消耗能量大,不经济的问题,现提出如下方案,其包括过滤器、降温除湿器、多个压缩机、冷却水降温器、热水驱动型溴化锂制冷机组、末级能量回收器和多个冷却器,过滤器的出气口与降温除湿器连接,多个压缩机包括第一级压缩机、第二级压缩机、第三级压缩机和第四级压缩机,多个冷却器包括第一级冷却器、第二级冷却器和第三级冷却器；降温除湿器与第一级压缩机连接,第一级压缩机与第一级冷却器连接。本发明流程简单,改造方便,各单元技术较为成熟,便于工业化利用。(The invention belongs to the technical field of compressor inlet cooling and dehumidification, compressor interstage cooling and compressor energy conservation, in particular to a compressor energy-saving device for low-temperature waste heat recovery and a method thereof, aiming at the problems that the traditional cooling and dehumidification device is electric refrigeration, and has large energy consumption and is not economical, the invention provides the following scheme, which comprises a filter, a cooling dehumidifier, a plurality of compressors, a cooling water cooler, a hot water driven lithium bromide refrigeration unit, a final-stage energy recoverer and a plurality of coolers, wherein an air outlet of the filter is connected with the cooling dehumidifier, the plurality of compressors comprise a first-stage compressor, a second-stage compressor, a third-stage compressor and a fourth-stage compressor, and the plurality of coolers comprise a first-stage cooler, a second-stage cooler and a third-stage cooler; the cooling dehumidifier is connected with the first-stage compressor, and the first-stage compressor is connected with the first-stage cooler. The invention has simple flow, convenient reconstruction, mature unit technology and convenient industrial utilization.)

1. A compressor energy-saving device for low-temperature waste heat recovery comprises a filter (1), a cooling dehumidifier (2), a plurality of compressors, a cooling water cooler (10), a hot water-driven lithium bromide refrigerating unit (12), a final-stage energy recoverer (11) and a plurality of coolers, and is characterized in that an air outlet of the filter (1) is connected with the cooling dehumidifier (2), the plurality of compressors comprise a first-stage compressor (3), a second-stage compressor (4), a third-stage compressor (5) and a fourth-stage compressor (6), and the plurality of coolers comprise a first-stage cooler (7), a second-stage cooler (8) and a third-stage cooler (9);

the cooling dehumidifier (2) is connected with the first-stage compressor (3), the first-stage compressor (3) is connected with the first-stage cooler (7), the first-stage cooler (7) is connected with the second-stage compressor (4), the second-stage compressor (4) is connected with the second-stage cooler (8), the second-stage cooler (8) is connected with the third-stage compressor (5), the third-stage compressor (5) is connected with the third-stage cooler (9), the third-stage cooler (9) is connected with the fourth-stage compressor (6), the fourth-stage compressor (6) is connected with the last-stage energy recoverer (11), the cooling dehumidifier (2) is connected with the hot water driving type lithium bromide refrigerating unit (12), the cooling water cooler (10) is connected with the hot water driving type lithium bromide refrigerating unit (12), and the hot water driving type lithium bromide refrigerating unit (12) is connected with the energy recoverer (11).

2. The energy-saving device for the low-temperature waste heat recovery compressor is characterized in that a cooling water inlet is connected to each of the first-stage cooler (7), the second-stage cooler (8), the third-stage cooler (9), the cooling water cooler (10) and the hot water driven lithium bromide refrigerating unit (12).

3. A low temperature waste heat recovery compressor economizer as claimed in claim 1 wherein the filter (1) is provided with an air inlet.

4. A low temperature waste heat recovery compressor economizer as claimed in claim 1 wherein the final energy recovery unit (11) is provided with a compressed gas outlet.

5. The use method of the compressor energy-saving device for recovering the low-temperature waste heat is characterized by comprising the following steps of:

s1: when in use, the electrical equipment is switched on, the air enters the filter (1) through the air inlet, the air is filtered by the filter (1) and then enters the cooling dehumidifier (2), the cooling dehumidifier (2) filters and dehumidifies the air, the air after cooling and dehumidifying enters the first-stage compressor (3), the air enters the first-stage cooler (7) after temperature rise and pressure rise for cooling and enters the second-stage compressor (4) at a lower temperature, can reduce the energy consumption of the second-stage compressor (4), enters the second-stage cooler (8) for cooling, enters the third-stage compressor (5) for compression, then the gas enters a third-stage cooler (9) for cooling, enters a fourth-stage compressor (6) for compressing to obtain high-temperature and high-pressure dry gas, and the high-temperature and high-pressure gas enters a final-stage energy recoverer (11) for converting heat into hot water to obtain dry compressed air;

s2: the hot water generated by the chilled water circulation final-stage energy recoverer (11) enters a lithium bromide refrigerating unit (12) to be used as power to drive the unit to refrigerate and obtain chilled water, one part of chilled water enters a cooling water cooler (10), the other part of chilled water for cooling the cooling water enters an air compressor inlet cooling dehumidifier, the chilled water heated after use enters the lithium bromide refrigerating unit (12) again to finish circulation,

s3: cooling water of a part of cooling water circulation enters a cooling water cooler (10), a main cooling water pipeline is mixed after the temperature is reduced, the cooling water enters a plurality of coolers, heat generated by a plurality of compressors is taken away, and the cooling water heated after being used returns to the cooling water return water again to complete circulation.

Technical Field

The invention relates to the technical field of compressor inlet cooling and dehumidification, compressor interstage cooling and compressor energy conservation, in particular to a compressor energy-saving device and method for low-temperature waste heat recovery.

Background

In many industrial enterprises, an air compressor is an essential device for ensuring normal production and is one of the devices with high energy consumption, and the compressor (compressor) is a driven fluid machine for raising low-pressure gas into high-pressure gas. The centrifugal air compressor is a heart of a refrigeration system, low-temperature and low-pressure refrigerant gas separated by a gas-liquid separator is sucked from an air suction pipe, a piston is driven by the operation of a motor to compress the refrigerant gas, high-temperature and high-pressure refrigerant gas is discharged to an exhaust pipe, power is provided for refrigeration cycle, an air cooler and an oil cooler are arranged in a traditional air compressor and used for cooling compressed air and lubricating oil respectively, the cooler is generally a shell-and-tube heat exchanger, heat obtained by exchange is directly discharged, the centrifugal air compressor is generally in a three-to-four-stage compression mode in operation, an intermediate cooler is arranged in an intermediate stage, heat in the high-temperature and high-pressure compressed air is exchanged by using cooling water, and the heat is radiated to the atmosphere through a cooling tower fan so as to ensure the safe and stable operation of the air compressor. In the above process, the heat carried by the high-temperature, high-pressure gas corresponds approximately to 3/4 of the power of the air compressor, which is generally at a temperature between 90 ℃ and 100 ℃ and even up to 150 ℃. In the process of cooling the system by using a cooling water heat dissipation system of the centrifugal air compressor, a large amount of heat energy is wasted without end. The waste heat recovery of the centrifugal compressor is determined by the design structure and the working principle of the centrifugal compressor, and the working process of the centrifugal compressor is that the centrifugal compressor compresses gas after sucking the gas, so that the pressure of the gas is increased (namely, kinetic energy is converted into pressure energy). The motor rotates to drive the gear and the rotor shaft, then the impeller obtains the rotating power, and the external air is sucked into the inlet of the impeller. The sucked gas is then accelerated and flows toward the top end of the impeller due to the centrifugal force during the operation of the impeller. High-speed gas flows to the diffuser through the impeller, and the flow speed of the gas is reduced and the pressure of the gas is increased through expansion due to the change of the area in the diffuser. Also as the gas flow passes through the volute, the gas pressure is increased by the progressive reduction in gas flow velocity due to the progressive increase in flow area. When the compressor works, the temperature of air is increased when the air is compressed, and the higher the temperature of the air is, the more energy is consumed by compression.

In an ideal isothermal compression process, work consumed by compression is the least, so when high-pressure gas is prepared, a multi-stage compression joint interstage cooling mode is often adopted, air enters a first-stage compressor after being filtered, enters a first-stage cooler after being heated and pressurized, and enters a next-stage compressor after being cooled.

In addition, the inlet air temperature and humidity of the air compressor set also have a great influence on the power consumption thereof. Therefore, a cooling and dehumidifying device is also necessary to be added in front of the compressor unit. The traditional cooling and dehumidifying device is electric refrigeration, which consumes large energy and is uneconomical.

Disclosure of Invention

The invention aims to solve the defects that the traditional cooling and dehumidifying device is electric refrigeration, consumes large energy and is not economical, and provides a compressor energy-saving device for recovering low-temperature waste heat and a method thereof.

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

a compressor energy-saving device for recovering low-temperature waste heat comprises a filter, a cooling dehumidifier, a plurality of compressors, a cooling water cooler, a hot water driving type lithium bromide refrigerating unit, a final-stage energy recoverer and a plurality of coolers, wherein an air outlet of the filter is connected with the cooling dehumidifier, the plurality of compressors comprise a first-stage compressor, a second-stage compressor, a third-stage compressor and a fourth-stage compressor, and the plurality of coolers comprise a first-stage cooler, a second-stage cooler and a third-stage cooler;

the cooling dehumidifier is connected with the first-stage compressor, the first-stage compressor is connected with the first-stage cooler, the first-stage cooler is connected with the second-stage compressor, the second-stage compressor is connected with the second-stage cooler, the second-stage cooler is connected with the third-stage compressor, the third-stage compressor is connected with the third-stage cooler, the third-stage cooler is connected with the fourth-stage compressor, the fourth-stage compressor is connected with the last-stage energy recoverer, the cooling dehumidifier is connected with the hot water driving type lithium bromide refrigerating unit, the cooling water cooler is connected with the hot water driving type lithium bromide refrigerating unit, and the hot water driving type lithium bromide refrigerating unit is connected with the last-stage energy.

Preferably, the first-stage cooler, the second-stage cooler, the third-stage cooler, the cooling water cooler and the hot-water-driven lithium bromide refrigerating unit are all connected with cooling water inlets.

Preferably, the filter is provided with an air inlet.

Preferably, the final energy recovery device is provided with a compressed gas outlet.

Preferably, the use method of the compressor energy-saving device for recovering the low-temperature waste heat comprises the following steps:

s1: when the air conditioner is used, electrical equipment is connected with a power supply and a controller, air enters a filter through an air inlet, enters a cooling dehumidifier after being filtered by the filter, is filtered and dehumidified by the cooling dehumidifier, enters a first-stage compressor, enters a first-stage cooler for cooling after being heated and boosted, enters a second-stage compressor at a lower temperature, can reduce the energy consumption of the second-stage compressor, enters the second-stage cooler for cooling, enters a third-stage compressor for compression, then enters a third-stage cooler for cooling, enters a fourth-stage compressor, is compressed to obtain high-temperature and high-pressure dry gas, and enters a final-stage energy recoverer to convert heat into hot water to obtain dry compressed air;

s2: the hot water generated by the last-stage energy recoverer of the chilled water circulation enters a lithium bromide refrigerating unit to be used as power to drive the unit to refrigerate to obtain chilled water, one part of chilled water enters a cooling water cooler to cool the chilled water, the other part of chilled water enters an air compressor inlet cooling dehumidifier to cool the chilled water, the chilled water heated after use enters the lithium bromide refrigerating unit again to complete the circulation,

s3: cooling water of a part of cooling water circulation enters the cooling water cooler, a main cooling water pipeline is mixed after the temperature is reduced, the cooling water enters the plurality of coolers, heat generated by the plurality of compressors is taken away, and the cooling water heated after being used returns to the cooling water return water again to complete circulation.

Compared with the prior art, the invention has the advantages that:

(1) the waste heat at the outlet of the air compressor provides power for the lithium bromide refrigerating unit, and a part of the prepared chilled water enters the inlet cooling dehumidifier of the air compressor to cool and dehumidify the inlet air. The other part of the chilled water is used for cooling the cooling water, so that the interstage cooling efficiency is improved, and the cooling circulation power consumption is reduced. Compared with the conventional air compressor system, the low-temperature waste heat at the outlet of the air compressor is fully utilized, the efficiency of the air compressor and cooling circulating water is improved, and the comprehensive energy consumption is reduced;

(2) the energy-saving method for the compressor for recovering the low-temperature waste heat mainly takes the low-temperature industrial waste heat as the drive, consumes little extra external electric energy, and thus, achieves the purposes of energy conservation and emission reduction.

(3) The invention tries to utilize the low-temperature heat which can not be utilized by the outlet of the compressor through the lithium bromide refrigeration equipment.

(4) The invention can simultaneously take the cooling and dehumidification of the inlet of the compressor, the interstage cooling and the outlet cooling into consideration, thus obtaining the finished high-pressure air suitable for use and reducing the energy consumption in the compression process.

(5) The invention has simple flow, convenient reconstruction, mature unit technology and convenient industrial utilization.

Drawings

Fig. 1 is a schematic structural diagram of a compressor energy-saving device for low-temperature waste heat recovery and a method thereof according to the present invention.

In the figure: 1. a filter; 2. a cooling dehumidifier; 3. a first stage compressor; 4. a second stage compressor; 5. a third stage compressor; 6. a fourth stage compressor; 7. a first stage cooler; 8. a second stage cooler; 9. a third stage cooler; 10. a cooling water cooler; 11. a final-stage energy recoverer; 12. hot water driven refrigeration lithium bromide unit.

Detailed Description

The technical solutions in the embodiments will be described clearly and completely with reference to the drawings in the embodiments, and it is obvious that the described embodiments are only a part of the embodiments, but not all embodiments.

Example one

Referring to fig. 1, a compressor energy-saving device for low-temperature waste heat recovery comprises a filter 1, a cooling dehumidifier 2, a plurality of compressors, a cooling water cooler 10, a hot water-driven lithium bromide refrigerating unit 12, a final-stage energy recoverer 11 and a plurality of coolers, wherein an air outlet of the filter 1 is connected with the cooling dehumidifier 2, the plurality of compressors comprise a first-stage compressor 3, a second-stage compressor 4, a third-stage compressor 5 and a fourth-stage compressor 6, the plurality of coolers comprise a first-stage cooler 7, a second-stage cooler 8 and a third-stage cooler 9, the cooling dehumidifier 2 is connected with the first-stage compressor 3, the first-stage compressor 3 is connected with the first-stage cooler 7, the first-stage cooler 7 is connected with the second-stage compressor 4, the second-stage compressor 4 is connected with the second-stage cooler 8, the second-stage cooler 8 is connected with the third-stage compressor 5, the third-stage compressor 5 is connected, the third stage cooler 9 is connected with the fourth stage compressor 6, the fourth stage compressor 6 is connected with the final stage energy recoverer 11, the cooling dehumidifier 2 is connected with the hot water drive type lithium bromide refrigerating unit 12, the cooling water cooler 10 is connected with the hot water drive type lithium bromide refrigerating unit 12, the hot water drive type lithium bromide refrigerating unit 12 is connected with the final stage energy recoverer 11, if the high-temperature water is directly pumped by a pump when the condensed water recoverer is used, the condensed water can be vaporized by the negative pressure formed before the pump, and cavitation is caused. In severe cases, the gas volume suddenly expands to burst and damage the water pump. Therefore, the traditional condensate water recovery method is to pump the condensate water after cooling. This makes it impossible to use a large amount of heat energy contained in the condensed water, and the water quality deteriorates and the water treatment is carried out again because the condensed water is mixed with untreated cold water. The condensate water recoverer is designed with cavitation eliminating measures, and can ensure that the water pump directly pumps high-temperature condensate water without cavitation. The cavitation of the water pump is solved by the pressure regulating device, the cavitation eliminating device and the special water pump in the tank body. Therefore, high-temperature condensed water and condensed water recoverer is realized, the condensed water recoverer can completely and closely recover high-energy secondary steam, and the volume of the water collecting container is reduced. The automatic control system is adopted to recover the condensed water energy in time, so that the energy waste is minimized, the oxygen corrosion is avoided, and the secondary steam is eliminated.

In this embodiment, the first-stage cooler 7, the second-stage cooler 8, the third-stage cooler 9, the cooling water cooler 10, and the hot-water-driven lithium bromide refrigeration unit 12 are all connected to a cooling water inlet.

In this embodiment, the filter 1 is provided with an air inlet.

In this embodiment, the final energy recovery unit 11 is provided with a compressed gas outlet.

In this embodiment, a method for using a compressor energy saving device with low-temperature waste heat recovery includes the following steps:

s1: when the air conditioner is used, electrical equipment is connected with a power supply and a controller, air enters a filter 1 through an air inlet, enters a cooling dehumidifier 2 after being filtered by the filter 1, is filtered and dehumidified by the cooling dehumidifier 2, enters a first-stage compressor 3, enters a first-stage cooler 7 for cooling after being heated and boosted, enters a second-stage compressor 4 at a lower temperature, can reduce the energy consumption of the second-stage compressor 4, enters a second-stage cooler 8 for cooling, enters a third-stage compressor 5 for compression, then enters a third-stage cooler 9 for cooling, enters a fourth-stage compressor 6, is compressed to obtain high-temperature and high-pressure dry gas, and enters a last-stage energy recoverer 11 to obtain dry compressed air after heat is converted into hot water;

s2: the hot water produced by the last-stage energy recoverer 11 of the chilled water circulation enters a lithium bromide refrigerating unit 12 to be used as power to drive the unit to refrigerate and obtain chilled water, one part of chilled water enters a cooling water cooler 10, the other part of chilled water for cooling the cooling water enters an air compressor inlet cooling dehumidifier, the chilled water heated after use enters the lithium bromide refrigerating unit 12 again to finish the circulation,

s3: in cooling water circulation some cooling water got into cooling water cooler 10, mix into main cooling water pipeline after the cooling temperature, the cooling water gets into a plurality of coolers, takes away the heat that a plurality of compressors produced, and the cooling water that heaies up after the use gets back to the cooling water return water again, accomplishes the circulation.

Example two

Referring to fig. 1, a compressor economizer of low temperature waste heat recovery, including filter 1, filter 1 can filter the air, cooling dehumidifier 2 can cool down and dehumidify the air, a plurality of compressors, the compressor compresses the air, cooling water cooler 10, hot water drive type lithium bromide refrigerating unit 12, last-stage energy recoverer 11 and a plurality of cooler, filter 1's gas outlet is connected with cooling dehumidifier 2, the compressor is air compressor (through the compression of raw materials air compressor machine, the air obtains 0.9 ~ 1.0 MPa's pressure), a plurality of compressors include first-stage compressor 3, second-stage compressor 4, third-stage compressor 5 and fourth-stage compressor 6, the cooler is one type of heat transfer equipment, for cooling fluid. Water or air is typically used as a coolant to remove heat. Coolers are a class of heat exchange devices that cool a fluid. Water or air is typically used as a coolant to remove heat. There are dividing wall type coolers, spray type coolers, jacketed type coolers, coil type coolers, etc. The pure water, water wind, oil water and oil wind cooling device is widely used for matching large electrical equipment such as a high-power silicon rectifying and induction furnace, an intermediate frequency furnace and the like as a cooling protection auxiliary machine, a plurality of coolers comprise a first-stage cooler 7, a second-stage cooler 8 and a third-stage cooler 9, a cooling dehumidifier 2 is connected with a first-stage compressor 3, the first-stage compressor 3 is connected with the first-stage cooler 7, the first-stage cooler 7 is connected with a second-stage compressor 4, the second-stage compressor 4 is connected with the second-stage cooler 8, the second-stage cooler 8 is connected with a third-stage compressor 5, the third-stage compressor 5 is connected with the third-stage cooler 9, the third-stage cooler 9 is connected with a fourth-stage compressor 6, the fourth-stage compressor 6 is connected with a last-stage energy recoverer 11, the cooling dehumidifier 2 is connected with a hot water driving type lithium bromide refrigerating unit 12, and a cooling water cooler 10 is connected, the driving lithium bromide refrigerating unit of hot water 12 is connected with final-stage energy recoverer 11, and cooling dehumidifier 2 increases the module that adjusts the temperature (intensification and cooling functional module) on the basis of ordinary dehumidifier, controls the wet load and the cold/heat of air simultaneously, divide into according to the condensation mode: an air-cooled temperature-adjusting dehumidifier and a water-cooled temperature-adjusting dehumidifier.

In this embodiment, the first stage cooler 7, the second stage cooler 8, the third stage cooler 9, the cooling water cooler 10 and the hot water drive type lithium bromide refrigerator group 12 are all connected with a cooling water inlet, and the hot water drive type lithium bromide refrigerator group 12 operating principle: the absorption type refrigeration system is used for cooling by taking hot water as power, and is suitable for all application occasions with residual heat water of more than 70 ℃, such as cooling hot water of a generator set of a distributed energy combined cooling heating and power system, high-temperature cooling hot water of a generator set for generating mine gas, garbage and methane, industrial residual heat, waste hot water and the like. The hot water type lithium bromide unit adopts a special system structure and a special solution circulation flow, can realize the high-efficiency recycling of a low-temperature heat source, can also realize the large temperature difference utilization of the heat source, and adapts to the technological requirements.

In this embodiment, be provided with air intlet on the filter 1, be provided with the filter screen on the filter 1, can carry out the primary filtration through the filter screen, the filter screen can be dismantled.

In this embodiment, the final energy recovery unit 11 is provided with a compressed gas outlet.

In this embodiment, a method for using a compressor energy saving device with low-temperature waste heat recovery includes the following steps:

s1: when the air conditioner is used, electrical equipment is connected with a power supply and a controller, air enters a filter 1 through an air inlet after being filtered by a filter screen, enters a cooling dehumidifier 2 after being filtered by the filter 1, and is filtered and dehumidified by the cooling dehumidifier 2, the operation is repeated for a plurality of times until the air enters a final-stage compressor (a fourth-stage compressor 6), high-temperature and high-pressure dry gas is obtained after compression, the high-temperature and high-pressure gas enters a final-stage energy recoverer 11, and heat is converted into hot water to obtain dry compressed air;

s2: the hot water produced by the last-stage energy recoverer 11 of the chilled water circulation enters a lithium bromide refrigerating unit 12 to be used as power to drive the unit to refrigerate and obtain chilled water, one part of chilled water enters a cooling water cooler 10, the other part of chilled water for cooling the cooling water enters an air compressor inlet cooling dehumidifier, the chilled water heated after use enters the lithium bromide refrigerating unit 12 again to finish the circulation,

s3: part of cooling water in the cooling water circulation enters a cooling water cooler 10, the cooling water is mixed into a main cooling water pipeline after the temperature is reduced, the cooling water enters a plurality of coolers to take away heat generated by a plurality of compressors, and the cooling water heated after being used returns to the cooling water for returning water to finish the circulation;

s4: the recovered heat is C.G.rho.DELTA.T, wherein C is the constant pressure specific heat capacity of the compressed air and has a constant of 1.05 KJ/(kg. DEG C)

G is the volume flow of the compressed air of the air compressor according to the average load, namely 110000Nm 3/h.

Rho is the density of the compressed air, and the air parameter table is checked to obtain rho which is 1.18kg/Nm3

And delta T is the temperature difference between the inlet temperature of the hot compressed air into the heat exchanger and the temperature after the waste heat is recycled. The average value of the temperature of the circulating water tank in operation is 40 ℃, and if the heat exchanger is designed according to the end difference of 10 ℃, the temperature of the compressed air after waste heat recovery is calculated according to 50 ℃. The fourth stage exhaust temperature of the centrifugal air compressor is about 100 ℃, and the scheme is calculated according to 100 ℃.

Then Δ T ═ tin-tout ═ 100-50 ═ 50 ℃, then a secondary heat value of C · G · ρ · ═ Δ T ═ 1.05 × 120000 × 1.18 × 50 ═ 7434000KJ/h, converted into thermal power, i.e. Q ═ 2065 KW.

Therefore, the total recovered thermal power Q is 2065 KW. The heat is equivalent to 2.95 tons of steam.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered as the technical solutions and the inventive concepts of the present invention in the technical scope of the present invention.