Precooling heat exchange system of oxygen generator

Abstract

The invention relates to a precooling heat exchange system of an oxygenerator. An outdoor circulation system is used for cooling and heat exchange and then circulating to an indoor heat exchange system for heat exchange; the system further comprises a control system, the control output end of the control system is connected to the outdoor circulating system, the signal input end of the control system is connected to the indoor circulating system, the indoor circulating system comprises a tubular heat exchanger, a water-cooling water chilling unit and an indoor circulating pump, and primary industrial water is cooled through the tubular heat exchanger; the outdoor circulating system comprises an outdoor plate heat exchanger, a closed cooling tower and an outdoor circulating pump, and when the outdoor environment temperature is lower than-2 DEG C, the temperature formed by the tubular heat exchanger completing the indoor circulating system is reduced through natural low-temperature heat exchange of the outdoor plate heat exchanger; a shell pass heat exchange medium of the tubular heat exchanger is cooled in the outdoor closed cooling tower; the power consumption is greatly reduced, and high-efficiency heat exchange and energy-saving operation of the pre-cooling system is finally realized.

Description

Technical Field

[0001] The invention relates to the technical field of oxygen production technology, and in particular to a precooling heat exchange system for an oxygen generator. Background Art

[0002] 35000m designed by Linde 3 The core of the precooling system process of the / h oxygen generator is to cool the high-temperature compressed air of 100℃ at the end of the air compressor to below 18℃ through ultra-low temperature cooling water of 7℃-15℃, and then enter the molecular sieve system for purification, and finally enter the air separation unit for distillation to extract qualified products of oxygen, nitrogen and argon.

[0003] The ultra-low temperature cooling water of 7℃-15℃ in the oxygen pre-cooling process system is obtained by secondary cooling of industrial circulating water at 24℃-33℃. The secondary cooling of industrial water is carried out by three chillers as the cold source, of which two have a cooling capacity of 1200kw and one has a cooling capacity of 1500kw. The chillers consume a lot of electricity and have high production costs. Even in winter, chillers are still used to cool the cooling water, which does not effectively utilize the low temperature weather in the northeast region in winter and reduce the water temperature of the oxygen pre-cooling process through natural low-temperature heat exchange. Summary of the invention

[0004] The present invention provides an oxygen concentrator precooling heat exchange system. Through the outdoor circulation system, indoor circulation system and control system of the system, not only the cold source is stabilized but also the industrial refrigeration machine is shut down, thus greatly reducing the power consumption and finally realizing the high-efficiency heat exchange and energy-saving operation of the precooling system.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An oxygen concentrator precooling heat exchange system comprises an outdoor circulation system and an indoor circulation system, wherein the indoor circulation system comprises an indoor heat exchanger, a water-cooled chiller and an indoor circulation pump, wherein the outdoor circulation system cools down and exchanges heat before circulating to the indoor heat exchange system, wherein the water-cooled chiller of the indoor circulation system flows the refrigerated circulating water into the heat exchanger for heat exchange and then the indoor circulation pump pumps out the exchanged water; further comprising a control system, wherein the control output end of the control system is connected to the outdoor circulation system, and the signal input end of the control system is connected to the indoor circulation system, wherein the indoor heat exchanger is a shell-and-tube heat exchanger;

[0007] The outdoor circulation system includes an outdoor plate heat exchanger, a closed cooling tower, and an outdoor circulation pump. When the outdoor ambient temperature is lower than -2°C, the temperature formed by the shell-and-tube heat exchanger that completes the indoor circulation system is cooled by natural low-temperature heat exchange of the outdoor plate heat exchanger. The shell-side heat exchange medium of the shell-and-tube heat exchanger is cooled in the outdoor closed cooling tower. The outdoor circulation pump provides circulation power for the outdoor plate heat exchanger.

[0008] Furthermore, the tube side of the shell-and-tube heat exchanger of the indoor circulation system is primary industrial water, and the shell side is the heat exchange medium ethylene glycol.

[0009] Furthermore, the indoor circulating water pump parameter is 115~120m 3 / h, outlet pressure 10~15Bar.

[0010] Furthermore, the circulating medium of the outdoor plate heat exchanger of the outdoor circulation system is ethylene glycol antifreeze.

[0011] Furthermore, the outdoor circulation pump has a power of 15KW, ensuring a flow rate of 110-160m 3 / h.

[0012] Furthermore, it also includes fans, the number of which is 18 to 20, and the fans are arranged on the top of the outdoor plate heat exchanger.

[0013] Furthermore, the final heat exchange temperature of the outdoor plate heat exchanger is controlled to be 5-8°C.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1) Through the outdoor circulation system, indoor circulation system and control system of this system, not only the cold source is stabilized, but also the industrial refrigeration machine is shut down, which greatly reduces the power consumption and finally realizes the high-efficiency heat exchange and energy-saving operation of the pre-cooling system;

[0016] 2) Realize long-term energy-saving operation in winter. The original system has a single chiller with a power consumption of 247kw / h and 497,900 yuan. After changing to this system, the power consumption in winter is 90,700 yuan, and the overall energy saving benefit in winter is 407,200 yuan;

[0017] 3) Make substantial contributions to the low-carbon green development of oxygen production, reducing carbon emissions by more than 700 tons;

[0018] 4) The old and new systems are set to switch automatically according to the temperature conditions, so as to achieve precise control of the operation of high-energy-consuming refrigerators and flexibly reduce energy consumption;

[0019] 5) Reduce the industrial water consumption of industrial refrigerant condensers, reduce the industrial water demand of the precooling system, and reduce the production line load. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention.

[0021] Figure 2 It is a structural block diagram of the natural heat exchange and large refrigerator switching described in the present invention. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0023] See Figure 1 , is a schematic diagram of the structure of the present invention. The present invention provides an oxygen concentrator precooling and heat exchange system, including an outdoor circulation system, an indoor circulation system, a fan and a control system. The outdoor circulation system cools down and exchanges heat and then circulates to the indoor heat exchange system for heat exchange. The control output end of the control system is connected to the outdoor circulation system, and the signal input end of the control system is connected to the indoor circulation system. The indoor circulation system includes an indoor heat exchanger, a water-cooled chiller and an indoor circulation pump. The indoor heat exchanger adopts a shell-and-tube heat exchanger. The water-cooled chiller of the indoor circulation system flows the refrigerated circulating water into the heat exchanger for heat exchange, and then the indoor circulation pump pumps out the exchanged water. The primary industrial water is cooled by the shell-and-tube heat exchanger. The indoor circulation pump provides circulation power for the circulating medium in the shell-and-tube heat exchanger. The tube side of the shell-and-tube heat exchanger of the indoor circulation system is primary industrial water, and the shell side The heat exchange medium is ethylene glycol; the outdoor circulation system includes an external plate heat exchanger, a closed cooling tower, and an outdoor circulation pump. When the outdoor ambient temperature is lower than -2°C, the temperature formed by the shell and tube heat exchanger of the indoor circulation system is cooled by the natural low-temperature heat exchange of the outdoor plate heat exchanger, completing the natural heat exchange instead of the large refrigerator, achieving significant energy saving. The shell-side heat exchange medium of the shell and tube heat exchanger is cooled in the outdoor closed cooling tower. The outdoor circulation pump provides circulation power for the outdoor plate heat exchanger. The outdoor circulation pump provides circulation power for the outdoor plate heat exchanger. The circulation medium of the outdoor plate heat exchanger of the outdoor circulation system is ethylene glycol antifreeze. The number of fans is 20, which are arranged on the top of the outdoor plate heat exchanger. The fan power is 1.5KW fan to achieve efficient heat exchange of the outdoor plate heat exchanger.

[0024] In the oxygen generator compressed air cooling process, the high-temperature compressed air discharged from the air compressor is cooled by chilled water. The preparation of chilled water is completed by 2 to 3 industrial refrigerators. The oxygen generator precooling heat exchange system of the present invention is used to replace the heat exchange circulation system of the existing industrial refrigerator. The indoor circulating water pump parameter is set to a flow rate of 118m 3 / h, outlet pressure 10Bar, outdoor circulation pump is low power and high efficiency circulation pump, power is 15KW, guaranteed flow rate 160m 3 / h, outdoor heat exchange area is about 100m 2 The outdoor circulation system will complete the temperature saturated ethylene glycol refrigerant formed by the indoor shell and tube heat exchanger to achieve cooling through natural low-temperature heat exchange through the outdoor plate heat exchanger. After cooling, it will be circulated to the indoor heat exchanger for heat exchange with industrial water. The outdoor circulation pump drives the refrigerant ethylene glycol to circulate through the indoor shell and tube heat exchanger and then circulate to the outdoor plate heat exchanger, forming automatic circulation and heat dissipation of the refrigerant.

[0025] See Figure 2 When the outdoor ambient temperature is lower than -2℃, the temperature formed by the shell-and-tube heat exchanger in the indoor circulation system will be cooled down through the natural low-temperature heat exchange of the outdoor plate heat exchanger, completing the natural heat exchange instead of the large refrigerator. The closed cooling tower is outdoors. The circulation formed by it and the outdoor circulation pump is to lead the refrigerant ethylene glycol in the outdoor plate heat exchanger to the outdoor closed cooling tower. The outdoor closed cooling tower cools down the ethylene glycol and restores its heat exchange capacity with the industrial water in the indoor circulation system that also enters the outdoor plate heat exchanger after returning to the outdoor plate heat exchanger.

[0026] The outdoor plate heat exchanger is the intersection of the outdoor circulation system refrigerant glycol and the indoor circulation system circulating industrial water. The two complete the heat exchange, thus replacing the heat exchange between the water-cooled chiller and the industrial water.

[0027] The indoor circulation pump circulates the industrial water to the outdoor plate heat exchanger, where it completes heat exchange with the refrigerant ethylene glycol entering from the outdoor circulation system before entering the next process flow.

[0028] The control system adjusts the refrigerant ethylene glycol at an outdoor temperature of 0°C to -30°C, so that the final heat exchange temperature on the outdoor plate heat exchanger side is controlled to 5-8°C, which is the optimal heat exchange temperature of the compressed air at the front end of the molecular sieve process, thereby achieving precise control of the process temperature.

[0029] The circulating water of the precooling system exchanges heat with low-temperature ethylene glycol through a heat exchanger. The temperature of ethylene glycol before heat exchange is 5°C-8°C. The circulating water is cooled from room temperature to 7°C-15°C through heat exchange to form low-temperature circulating water that enters the nitrogen cooling tower, thereby achieving the heat exchange purpose required by the present invention.

[0030] The temperature of ethylene glycol that completes heat exchange with the system circulating water in the heat exchanger rises, and is driven by a low-power and high-efficiency outdoor circulation pump to circulate through the pipeline to the outdoor plate heat exchanger. The outdoor plate heat exchanger is equipped with a low-power fan to realize forced air supply of low-temperature air. The ethylene glycol coolant exchanges heat with the outdoor low-temperature air efficiently and naturally in the outdoor plate heat exchanger. At the same time, the control system automatically and effectively controls the heat exchange temperature to be maintained at 5℃~8℃ and is driven by the indoor circulation pump again to enter the indoor shell and tube heat exchanger to form a cycle.

[0031] The above embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the above embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims

1. An oxygen concentrator precooling heat exchange system, comprising an outdoor circulation system and an indoor circulation system, wherein the indoor circulation system comprises an indoor heat exchanger, a water-cooled chiller and an indoor circulation pump, wherein the outdoor circulation system cools down and exchanges heat before circulating to the indoor heat exchange system, wherein the water-cooled chiller of the indoor circulation system flows the refrigerated circulating water into the heat exchanger for heat exchange and then the indoor circulation pump pumps out the exchanged water; characterized in that: It also includes a control system, wherein the control output end of the control system is connected to the outdoor circulation system, the signal input end of the control system is connected to the indoor circulation system, and the indoor heat exchanger is a shell-and-tube heat exchanger; The outdoor circulation system includes an outdoor plate heat exchanger, a closed cooling tower, and an outdoor circulation pump. When the outdoor ambient temperature is lower than -2°C, the temperature formed by the shell-and-tube heat exchanger that completes the indoor circulation system is cooled by natural low-temperature heat exchange of the outdoor plate heat exchanger. The shell-side heat exchange medium of the shell-and-tube heat exchanger is cooled in the outdoor closed cooling tower. The outdoor circulation pump provides circulation power for the outdoor plate heat exchanger.

2. The oxygen concentrator precooling heat exchange system according to claim 1, characterized in that: The tube side of the shell and tube heat exchanger of the indoor circulation system is primary industrial water, and the shell side is the heat exchange medium ethylene glycol.

3. The oxygen concentrator precooling heat exchange system according to claim 1, characterized in that: The indoor circulating water pump parameter is a flow rate of 115-120m 3 / h, outlet pressure 10~15Bar.

4. The oxygen concentrator precooling heat exchange system according to claim 1, characterized in that: The outdoor plate heat exchanger of the outdoor circulation system has a circulating medium of ethylene glycol antifreeze.

5. The oxygen concentrator precooling heat exchange system according to claim 1, characterized in that: The outdoor circulation pump has a power of 15KW, ensuring a flow rate of 110-160m 3 / h.

6. The oxygen concentrator precooling heat exchange system according to claim 1, characterized in that: It also includes fans, the number of which is 18 to 20, and the fans are arranged on the top of the outdoor plate heat exchanger.

7. The oxygen concentrator precooling heat exchange system according to claim 1, characterized in that: The final heat exchange temperature of the outdoor plate heat exchanger is controlled to be 5-8°C.

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