A refrigeration system

Abstract

The invention discloses a refrigeration system, comprising: a generator, provided with a liquid storage chamber for accommodating liquid ammonia and sodium nitrate solution, the generator being connected to a heat source, and an exhaust pipe being arranged at the upper end of the generator; a condenser, provided with a condensation chamber, and an inlet of the condensation chamber being connected to the exhaust pipe; an evaporator, provided with an evaporation chamber, and an inlet of the evaporation chamber being connected to an outlet of the condensation chamber through a liquid inlet pipe; an expansion valve being arranged on the liquid inlet pipe; an absorber, located below the generator, the absorber having an absorption chamber for accommodating sodium nitrate solution, an upper part of the absorption chamber being connected to an outlet of the evaporation chamber through a gas delivery pipe, the absorber being provided with a liquid delivery pipe and a reflux pipe, and the reflux pipe being provided with a reflux pump; a lithium bromide water refrigerator, a first cold water pipe and a second cold water pipe being arranged at a cold water output end of the lithium bromide water refrigerator, the first cold water pipe being connected to the condenser to cool the gas in the condensation chamber, and the second cold water pipe being connected to the absorber to cool the sodium nitrate solution in the absorption chamber.

Description

Technical Field

[0001] The invention relates to the technical field of refrigeration, and in particular to a sodium nitrate-liquid ammonia diffusion absorption refrigeration system. Background Art

[0002] There are several common absorption refrigeration methods at present: ammonia absorption refrigeration and ammonia hydrogen water absorption diffusion refrigeration. Although the refrigeration temperature of ammonia absorption refrigeration can reach dozens of degrees below zero, because the refrigerant pair is ammonia and water, both will evaporate when heated, which not only requires the installation of a distillation device, but also reduces the refrigeration efficiency. Ammonia hydrogen water diffusion refrigeration adds a diffusion gas - hydrogen as a balance gas on the basis of ammonia absorption refrigeration. Because the refrigerant pair is still ammonia and water, the disadvantage is similar to that of ammonia absorption refrigeration. The COP is generally around 0.4, which is difficult to meet large refrigeration needs. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a refrigeration system, which uses sodium nitrate and liquid ammonia as a refrigeration working medium pair, simplifies the equipment and reduces the requirements.

[0004] A refrigeration system according to an embodiment of the present invention includes: a generator having a liquid storage chamber for accommodating liquid ammonia and sodium nitrate solution, the generator being connected to a heat source, and an exhaust pipe being arranged at the upper end of the generator; a condenser having a condensation chamber, the inlet of which is connected to the exhaust pipe; an evaporator having an evaporation chamber, the inlet of which is connected to the outlet of the condensation chamber via a liquid inlet pipe; an expansion valve arranged on the liquid inlet pipe; an absorber located below the generator, the absorber having an absorption chamber for accommodating sodium nitrate solution, the upper part of which is connected to the evaporation chamber via a gas transmission pipe outlet, the absorber is provided with an infusion tube and a reflux tube, the upper end of the infusion tube is connected to the liquid storage chamber, the lower end of the infusion tube is connected to the upper part of the absorption chamber, the upper end of the reflux tube is connected to the liquid storage chamber, the lower end of the reflux tube extends to the lower part of the absorption chamber, and the reflux tube is provided with a reflux pump; a lithium bromide water refrigerator, the cold water output end of the lithium bromide water refrigerator is provided with a first cold water pipe and a second cold water pipe, the first cold water pipe is connected to the condenser to cool the gas in the condensation chamber, and the second cold water pipe is connected to the absorber to cool the sodium nitrate solution in the absorption chamber.

[0005] The refrigeration system according to the embodiment of the present invention has at least the following beneficial effects: the liquid ammonia-sodium nitrate diffusion refrigeration device uses sodium nitrate as the absorbent and liquid ammonia as the refrigerant. Sodium nitrate is a salt with a boiling point of 380°C, which is very different from the boiling point of liquid ammonia. Therefore, the distillation equipment is eliminated, the system is simplified, and the cost is reduced; the constant pressure specific heat is large, which is conducive to reducing the heat exchange area, miniaturizing the equipment, and reducing the occupied space; liquid ammonia-sodium nitrate is a relatively ideal absorption refrigeration working fluid pair, and the COP can also meet higher requirements. The refrigeration can reach below zero, meet larger refrigeration needs, and provide a larger range of use.

[0006] According to some embodiments of the present invention, the heat source is a hot water pipeline, and the hot water pipeline is above 110°C.

[0007] According to some embodiments of the present invention, the hot water pipeline is provided with a pressure pump.

[0008] According to some embodiments of the present invention, the first cold water pipe is provided with a coil in the condensing chamber, and the coil and the liquid inlet pipe perform heat exchange in the condensing chamber.

[0009] According to some embodiments of the present invention, the expansion valve is an electronic expansion valve.

[0010] According to some embodiments of the present invention, the infusion tube and the reflux tube are disposed at two ends of the absorber.

[0011] According to some embodiments of the present invention, one end of the exhaust pipe connected to the condensation chamber is configured to be bent upward.

[0012] According to some embodiments of the present invention, a middle portion of the gas delivery pipe is configured to bulge upward.

[0013] According to some embodiments of the present invention, the lithium bromide water refrigerator includes a second generator, and the second generator is connected to the heat source to achieve heating.

[0014] According to some embodiments of the present invention, the cold water output by the lithium bromide water refrigerator is 7°C to 9°C.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 Schematic diagram of the structure of the refrigeration system of some embodiments of the present invention. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0019] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., and orientation or state relationships indicated are based on the orientation or state relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] In the description of the present invention, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0021] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0022] Reference Figure 1Some embodiments of the present invention provide a refrigeration system, including: a generator 100, having a liquid storage chamber 101 for accommodating liquid ammonia and sodium nitrate solution, the generator 100 is connected to a heat source 110, and an exhaust pipe 102 is arranged at the upper end of the generator 100; a condenser 200, having a condensation chamber 201, and the inlet of the condensation chamber 201 is connected to the exhaust pipe 102; an evaporator 300, having an evaporation chamber 301, and the inlet of the evaporation chamber 301 is connected to the outlet of the condensation chamber 201 through a liquid inlet pipe 302; an expansion valve 400, which is arranged on the liquid inlet pipe 302; an absorber 500, which is located below the generator 100, and the absorber 500 has an absorption chamber 501 for accommodating sodium nitrate solution, and the upper part of the absorption chamber 501 is connected to the outlet of the evaporation chamber 301 through a gas transmission pipe 502, and the absorption chamber 501 is connected to the outlet of the evaporation chamber 301 through a gas transmission pipe 502. The absorber 500 is provided with an infusion tube 503 and a reflux tube 504, the upper end of the infusion tube 503 is connected to the liquid storage chamber 101, the lower end of the infusion tube 503 is connected to the upper part of the absorption chamber 501, the upper end of the reflux tube 504 is connected to the liquid storage chamber 101, the lower end of the reflux tube 504 extends to the lower part of the absorption chamber 501, the lower end of the reflux tube 504 is located below the liquid surface of the sodium nitrate solution in the absorption chamber 501, and the reflux tube 504 is provided with a reflux pump 505; a lithium bromide water refrigerator 600, the cold water output end of the lithium bromide water refrigerator 600 is provided with a first cold water pipe 601 and a second cold water pipe 602, the first cold water pipe 601 is connected to the condenser 200 to cool the gas in the condensation chamber 201, and the second cold water pipe 602 is connected to the absorber 500 to cool the sodium nitrate solution in the absorption chamber 501. It is understandable that the lithium bromide water refrigerator 500 is an existing technology and will not be described in detail. The lithium bromide water refrigerator 500 can produce cold water at 7° C. for cooling the condenser 200 and the absorber 400 .

[0023] Reference Figure 1The operation process of the refrigeration system is as follows: the liquid ammonia and sodium nitrate solution in the liquid storage chamber 101 are heated by the heat source 110, and the liquid ammonia is evaporated into ammonia gas by the heat. The ammonia gas moves upward through the exhaust pipe 102 and enters the condenser 200. The ammonia gas exchanges heat with the cold water in the first cold water pipe 501 in the condenser 200 and condenses into liquid ammonia. The liquid ammonia flows into the liquid inlet pipe 302. The liquid ammonia changes from high temperature and high pressure to low temperature and low pressure through the expansion valve 400, and then enters the evaporation chamber 301 of the evaporator 300. The liquid ammonia evaporates into ammonia gas in the evaporation chamber 301, and absorbs heat from the surrounding environment at the same time. Refrigeration is achieved; then the ammonia rises and enters the gas delivery pipe 502, the gas delivery pipe 502 is connected to the absorption chamber 501, and the ammonia is absorbed by the sodium nitrate solution in the absorption chamber 501. In order to ensure the ability of the sodium nitrate solution to absorb ammonia, the cold water of the second cold water pipe 502 is used to reduce the temperature of the sodium nitrate solution in the absorption chamber 401; the sodium nitrate solution that has absorbed ammonia is drawn into the liquid storage chamber 101 through the reflux pump 505, and part of the sodium nitrate solution in the liquid storage chamber 101 (liquid ammonia is heated and evaporated) enters the absorption chamber 501 through the delivery pipe 503, forming a cycle. The refrigeration system uses sodium nitrate as the absorbent and liquid ammonia as the refrigerant. Sodium nitrate is a salt with a boiling point of 380°C, which is very different from the boiling point of liquid ammonia. Therefore, the distillation equipment is eliminated, the system is simplified, and the cost is reduced; the constant pressure specific heat is large, which is conducive to reducing the heat exchange area, miniaturizing the equipment, and reducing the occupied space; liquid ammonia-sodium nitrate is a relatively ideal absorption refrigeration working fluid pair, and the COP can also meet higher requirements. The refrigeration can reach below zero degrees, meet larger refrigeration needs, and provide a wider range of uses.

[0024] Reference Figure 1 According to some embodiments of the present invention, the heat source 110 is a hot water pipeline, and the hot water pipeline is above 110°C. For example, an oil refinery in the petrochemical industry can produce a large amount of 120°C steam condensate per hour. At the same time, the dewaxing process of the oil refinery requires refrigeration, and the refrigeration temperature is -40°C and -20°C. The refrigeration system of the present invention can be used.

[0025] Reference Figure 1 According to some embodiments of the present invention, the hot water pipeline is provided with a pressure pump to increase the flow rate and enhance the heating capacity.

[0026] Reference Figure 1 According to some embodiments of the present invention, the first cold water pipe 601 is provided with a coil in the condensing chamber 201, and the coil exchanges heat with the liquid inlet pipe 302 in the condensing chamber 201. The coil increases the contact area and improves the cooling capacity of ammonia.

[0027] Reference Figure 1 According to some embodiments of the present invention, the expansion valve 400 is an electronic expansion valve 400, which can improve the control accuracy and enhance the refrigeration efficiency.

[0028] Reference Figure 1 According to some embodiments of the present invention, the infusion tube 503 and the return tube 504 are disposed at two ends of the absorber 500 to reduce mutual influence.

[0029] Reference Figure 1 According to some embodiments of the present invention, one end of the exhaust pipe 102 connected to the condensation chamber 201 is configured to be bent upward so that the sodium nitrate solution carried in the ammonia gas can flow back to the liquid storage chamber 101 .

[0030] Reference Figure 1 According to some embodiments of the present invention, the middle portion of the gas delivery pipe 502 is configured to bulge upward, which can prevent the ammonia gas from bringing liquid ammonia into the absorption chamber 501.

[0031] Reference Figure 1 According to some embodiments of the present invention, the lithium bromide water refrigerator 600 includes a second generator 610, and the second generator 610 is connected to the heat source 110 to achieve heating. The second generator 610 and the generator 100 use a common heat source, which simplifies the structure and improves efficiency.

[0032] Reference Figure 1 According to some embodiments of the present invention, the cold water output by the lithium bromide water refrigerator 600 is 7°C to 9°C.

[0033] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A refrigeration system, characterized in that: include: A generator having a liquid storage chamber for containing liquid ammonia and sodium nitrate solution, the generator being connected to a heat source, and an exhaust pipe being arranged at the upper end of the generator; A condenser having a condensation chamber, an inlet of the condensation chamber being connected to the exhaust pipe, and an end of the exhaust pipe connected to the condensation chamber being configured to be bent upward; An evaporator having an evaporation chamber, wherein the inlet of the evaporation chamber is connected to the outlet of the condensation chamber through a liquid inlet pipe; An expansion valve, arranged on the liquid inlet pipe; An absorber is located below the generator, the absorber has an absorption chamber for accommodating sodium nitrate solution, the upper part of the absorption chamber is connected to the outlet of the evaporation chamber through an air pipe, the middle part of the air pipe is configured to bulge upward, the absorber is provided with a liquid infusion pipe and a reflux pipe, the upper end of the liquid infusion pipe is connected to the liquid storage chamber, the lower end of the liquid infusion pipe is connected to the upper part of the absorption chamber, the upper end of the reflux pipe is connected to the liquid storage chamber, the lower end of the reflux pipe extends to the lower part of the absorption chamber, and the reflux pipe is provided with a reflux pump; A lithium bromide water refrigerator, wherein a first cold water pipe and a second cold water pipe are provided at a cold water output end of the lithium bromide water refrigerator, wherein the first cold water pipe is connected to the condenser to cool the gas in the condensation chamber, and the second cold water pipe is connected to the absorber to cool the sodium nitrate solution in the absorption chamber.

2. A refrigeration system according to claim 1, characterized in that: The heat source is a hot water pipeline, and the hot water pipeline is above 110°C.

3. A refrigeration system according to claim 2, characterized in that: The hot water pipeline is provided with a pressure pump.

4. A refrigeration system according to claim 1, characterized in that: The first cold water pipe is provided with a coil in the condensing chamber, and the coil and the liquid inlet pipe perform heat exchange in the condensing chamber.

5. A refrigeration system according to claim 1, characterized in that: The expansion valve is an electronic expansion valve.

6. A refrigeration system according to claim 1, characterized in that: The liquid infusion tube and the reflux tube are disposed at two ends of the absorber.

7. A refrigeration system according to claim 1, characterized in that: The lithium bromide water refrigerator comprises a second generator, and the second generator is connected to the heat source to achieve heating.

8. A refrigeration system according to claim 7, characterized in that: The cold water output by the lithium bromide water refrigerator is 7°C to 9°C.

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