RU2156418C1 - Autonomous cooling system with cryogenic working medium - Google Patents

Abstract

FIELD: autonomous cooling systems. SUBSTANCE: closed nitrogen loop of autonomous cooling system includes reservoir filled with liquid nitrogen, submersible centrifugal pump, air cooling panel placed in cooled heat-insulated vessel, vortex tube, mixing reservoir, throttle valve, Stirling cryogenic machine, Dewar flask, high-pressure pump and check valve. Mixing reservoir is connected with vortex tube by cold and hot flow lines with heat exchangers. Cooling loop of cryogenic machine passes through cold flow heat exchanger; it includes pump and heat exchanger communicated with surrounding medium. Cryogenic machine is driven by electric motor, special-purpose thermal engine or engine of transport facility. Hot flow heat exchanger is communicated with surrounding medium. EFFECT: avoidance of losses of nitrogen; possibility of thermostating various objects without disturbing composition of air. 1 dwg

Description

 The invention relates to the field of cryogenic technology and cryogenic refrigeration machines operating on the reverse Stirling cycle, can be used for thermostating of both special stationary objects and vehicles.

 Known technical solutions for the gasification of liquefied gases before distributing to consumers using high pressure pumps (Questions of deep cooling. Collection of articles edited by prof. MP Malkov. M .: Publishing House "Foreign Literature", 1961, p. 287-288).

 The device of the Dewar vessel for liquid nitrogen with vacuum-powder insulation is known (Sokolov E.Ya., Brodyansky V.M. Energy principles of heat transformation and cooling processes. Textbook for universities. - 2nd ed. M.: Energoizdat, 1981 , p. 202).

 A known scheme of a refrigeration unit with a vortex tube, which includes a gas source with high pressure (compressor), a vortex tube, a heat flow line with a butterfly valve, a cold flow line (Theoretical foundations of heat and refrigeration. Part 1. Technical thermodynamics. Uch. manual edited by prof.E.I. Guigo. L., 1974, p. 265).

 It is known that a vortex tube can be used to liquefy gases (RB Scott Low Temperature Technique. Translation under the editorship of Prof. MP Malkov. M: Publishing House of Foreign Literature., 1962, p. 50). However, when using a vortex tube, the liquefaction coefficient does not exceed 15% of the total amount of gas supplied to the tube.

 It is known that in the range of cryogenic temperatures (60 - 160 K), the reverse Stirling cycle is the most highly efficient cycle. The efficiency of cryogenic Stirling machines is almost 2 times higher compared to other plants used for gas liquefaction (Usyukin I.P. Installations, machines and apparatuses of cryogenic technology. M: Light and food industry, 1982, p. 185-186) .

 A device of the gas refrigerating machine Philips, operating on the reverse Stirling cycle, designed to liquefy the air and includes a block of heat exchangers: a condenser, a regenerator and a refrigerator. Helium is used as a working fluid in the refrigeration machine. (Questions of deep cooling. Collection of articles edited by prof. MP Malkov. M.: Publishing House "Foreign Literature", 1961, p. 35). However, liquid air has an increased fire hazard.

 It is known that nitrogen is a chemically inactive substance, is not toxic, and can be used to create an inert environment, due to its explosion and fire safety (Glinka N.L. General chemistry. Textbook for universities. - 22nd ed., Rev. L. : Chemistry, 1982, pp. 398 - 399). However, nitrogen production is an expensive process.

 A known system of nitrogen cooling in a heat-insulated car body, designed to transport products and allows you to quickly cool the internal volume of the body. The system includes a container with liquid nitrogen, a submersible centrifugal pump for supplying liquid nitrogen (Akulov L.A., Borzenko E.I., Soloviev V.A. Nitrogen cooling system in a thermally insulated car body. // Abstracts of international scientific. -tech.conf. "Refrigeration in Russia. Status and Prospects on the Eve of the XXI Century." // St. Petersburg, 1998, p. 32). However, this system involves filling the internal volume of the body with nitrogen and its subsequent release into the atmosphere, which does not allow it to be used for thermostating of inhabited premises and leads to the irretrievable loss of expensive gas - nitrogen.

 The technical result that can be obtained by carrying out the invention is to eliminate the irretrievable loss of nitrogen, the possibility of using the system for thermostating of various objects, without violating the composition of the air inside their objects, with a high level of explosion and fire safety.

 To achieve this technical result, an autonomous cooling system with a cryogenic working fluid, including a tank with liquid nitrogen, a submersible centrifugal pump for supplying liquid nitrogen, a cooled insulated volume, is equipped with a closed nitrogen circuit containing an air-cooling panel located in a cooled insulated volume, a vortex tube, mixing tank connected to the vortex tube by cold and warm flow lines with heat exchangers, a throttle valve, a cryogenic refrigeration a Stirling machine, a Dewar vessel, a high pressure pump supplying liquid nitrogen from a Dewar vessel to a container with liquid nitrogen, and a check valve, as well as a cooling circuit of a cryogenic Stirling machine passing through a cold flow heat exchanger and including a pump and a heat exchanger associated with environment, while the cryogenic Stirling machine is driven by an electric motor, a special heat engine or a vehicle engine, and the heat flux heat exchanger is connected to the environment.

 The introduction of a closed nitrogen circuit with a vortex tube, cold and warm flow lines with heat exchangers and a cryogenic Stirling machine, as well as a cooling circuit of a cryogenic machine connected with a closed nitrogen circuit through a cold flow line heat exchanger into an autonomous cooling system with a cryogenic working fluid allows one to obtain a new property, which consists in eliminating the release of evaporated nitrogen into the environment due to its condensation in the cryogenic Stirling machine and obtaining additional cold to reduce the power consumption for the drive of the cryogenic Stirling machine by reducing the upper temperature of the cycle of the machine.

 The drawing shows an autonomous cooling system with a cryogenic working fluid.

 The autonomous system consists of a closed nitrogen circuit, which includes a tank with liquid nitrogen 1, a submersible centrifugal pump 2, a thermally insulated cooled volume 3, an air-cooled panel 4, a vortex tube 5, a cold stream line 6 with a heat exchanger 7, a warm stream line 8 with a heat exchanger 9 , mixing tank 10, throttle valve 11, cryogenic Stirling refrigeration machine 12, including a condenser 13 and a refrigerator 14, a dewar vessel 15, a high pressure pump 16, a check valve 17, and a cooling circuit of a cryogenic machine 1 2, consisting of a pump 18, a heat exchanger 19 and passing through the heat exchanger 7 of the cold flow line 6. The heat exchanger 19 of the cooling circuit of the Stirling refrigeration machine 12 and the heat exchanger 9 of the heat flow line 8 are connected to the environment via pipelines 20 and 21, respectively. The drive of the Stirling refrigeration machine 12 can be carried out from an electric motor, a special heat engine or a vehicle engine (not shown in the drawing).

 Autonomous cooling system with a cryogenic working fluid works as follows.

 Liquid nitrogen from the tank 1 is fed by a submersible centrifugal pump 2 into the air-cooling panel 4 located in a thermally insulated cooled volume 3, cools the internal environment of the volume 4 to the desired temperature, while it is heated and goes into a gaseous state with high pressure. From the panel 4, gaseous high-pressure nitrogen enters the vortex tube 5, where it is divided into two streams: cold and warm. The cold stream through line 6 passes through the heat exchanger 7, where it cools the liquid of the cooling circuit of the Stirling refrigeration machine 12. The warm stream through line 8 passes through the heat exchanger 9, where it is cooled by heat exchange with the environment coming through pipelines 21. In the mixing tank 10 flows coming on lines 6 and 8 are mixed, then throttled in valve 11, in order to reduce pressure and cooling, and are sucked into the condenser 13 of the chiller 12, where the nitrogen condenses, passing into the liquid phase, then merges itself flow into the Dewar vessel 15, where, using the high pressure pump 16, through the check valve 17, is fed back into the tank with liquid nitrogen 1.

 In order to cool the cryogenic machine 12, a cooling system circuit is provided. In this circuit, heated from the working fluid of machine 12, the cooling liquid from the refrigerator 14 of the machine 12 is pumped to a heat exchanger 19 through a pump 18, where heat is exchanged with the environment (for example, atmospheric air) supplied through pipelines 20, while the cooling liquid is cooled to ambient temperature. Then the liquid is supplied to the heat exchanger 7 of the cold stream line 6, where it is cooled to a temperature below ambient temperature due to heat exchange with cold gaseous nitrogen, and enters again into the refrigerator 14. Due to the heat exchange of the coolant with a low temperature and the working fluid of the machine 12, there is a decrease in the upper temperature of the cycle of the Stirling machine 12, which leads to an increase in the refrigeration coefficient of the machine 12 and a decrease in power consumption for its drive.

Sources of information
1. Issues of deep cooling. Sat articles edited by prof. M.P. Malkova. M .: Publishing. "Foreign Literature", 1961, p. 287-288.

 2. Sokolov E. Ya., Brodyansky V.M. Energy fundamentals of heat transformation and cooling processes. Textbook manual for universities. 2nd ed. - M.: Energoizdat, 1981, p. 202.

 3. Theoretical foundations of heat and refrigeration. Part 1. Technical thermodynamics. Uch. allowance under the editorship of prof. E.I. Guigo. L., 1974, p. 265.

 4. P. B. Scott Low Temperature Technique. Translation Ed. prof. M.P. Malkova. M .: Publishing. foreign letter., 1962, p. 50.

 5. Usyukin I.P. Installations, machines and apparatuses of cryogenic equipment. M .: Light and food industry, 1982, p.185-186.

 6. Issues of deep cooling. Sat articles edited by prof. M.P. Malkova. M .: Publishing. "Foreign Literature", 1961, p. 35.

 7. Glinka N. L. General chemistry: Textbook for universities. - 22nd ed., Rev. L .: Chemistry, 1982, p. 398-399.

 8. Akulov L.A., Borzenko E.I., Soloviev V.A. Nitrogen cooling system in a thermally insulated car body. // Abstract. reports of international scientific and technical conf. "Refrigeration equipment in Russia. Status and prospects on the eve of the XXI century." // St. Petersburg, 1998, p. 32 is a prototype.

Claims (1)

 An autonomous cooling system with a cryogenic working fluid, including a nitrogen circuit containing a container with liquid nitrogen, a submersible centrifugal pump for supplying liquid nitrogen and a cooled insulated volume, characterized in that the nitrogen circuit is closed and provided with an air-cooling panel placed in a cooled insulated volume, a vortex a tube, a mixing tank connected with a vortex tube by cold and warm flow lines with heat exchangers, a throttle valve, a cryogenic machine Stirlin hectares, a Dewar vessel, a high pressure pump supplying liquid nitrogen from a Dewar vessel to a container with liquid nitrogen, and a check valve, and the system is equipped with a cooling circuit of a cryogenic Stirling machine passing through a cold flow heat exchanger and including a pump and a heat exchanger associated with the environment, the cryogenic Stirling machine is driven by an electric motor, a special heat engine or a vehicle engine, and the heat flux heat exchanger is connected to the environment.