Hydrate energy-storage temperature-control material and preparation method therefor

Patent metadata

Field	Value
Publication number	US-11911786-B2
Application number	US-202117628104-A
Country	US
Kind code	B2
Filing date	Jun 30, 2021
Priority date	Dec 18, 2020
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

The present invention discloses a hydrate energy-storage temperature-control material and a preparation method therefor. The material includes a refrigerant hydrate and a cross-linked polymer. The preparation method comprises the following steps: first, preparing a refrigerant hydrate by using a high-pressure reactor, and conducting grinding, crushing and sieving to obtain hydrate particles; then, uniformly spraying polytetrafluoroethylene suspended ultrafine powder onto the surface of the hydrate particles by using an electrostatic spraying device, and putting the hydrate particles into a plasma instrument to modify polytetrafluoroethylene so as to allow free radicals to be formed on the polytetrafluoroethylene powder surface; finally, subjecting monomers to graft polymerization with the free radicals on the polytetrafluoroethylene surface under the irradiation of a high-pressure mercury lamp of UV lighting system to stabilize the structure of the material, preparing a final product. According to the present invention, a hydrate energy-storage temperature-control material with good stability is prepared. A method capable of preparing various types of refrigerant hydrate materials is provided. The product can give full play to the advantages of hydrate energy storage and temperature control, can be periodically used, and can be used in various fields such as building, refrigeration, etc.

First claim

The invention claimed is:

1. A preparation method for a hydrate energy-storage temperature-control material, comprising the following steps:
step 1. generating a refrigerant hydrate;
step 2. crushing the hydrate: taking out the formed hydrate from a reactor, crushing, grinding and sieving by using a screen to obtain hydrate particles with a particle size of 180-250 μm and weighing same, and centrifuging by using a centrifugal machine at a revolving speed of not less than 2000 r/min for solid-liquid separation for 10-20 min;
step 3. spraying polytetrafluoroethylene suspended ultrafine powder onto the hydrate particles by using an electrostatic spraying device: placing the hydrate particles crushed in step 2 on a conveyor belt ( 5 ), and adding a high-voltage electrostatic field between a nozzle ( 4 ) and the hydrate particles ( 7 ), so the polytetrafluoroethylene suspended powder is adsorbed and coated onto the hydrate particles under the action of electrostatic force and gravity;
step 4. placing the hydrate particles ( 15 ) onto which the polytetrafluoroethylene powder is sprayed into a plasma instrument, and processing by using argon plasma so as to allow free radicals to be formed on the polytetrafluoroethylene surface;
step 5. placing a hydrate particles wrapped by modified PTFE powder into a vacuum closed container, heating a monomer solution until steam evaporates, keeping an airflow pressure at 40-50 Pa by using a throttle valve ( 8 ), introducing into the closed container ( 14 ), cooling the closed container ( 14 ) by using a water bath of 25-30° C. and irradiating by using a high-pressure mercury lamp ( 11 ) of ultraviolet lighting system for 80-90 min, to promote graft polymerization of a monomer and free radicals; obtaining the hydrate energy-storage temperature-control material.

2. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein generating the refrigerant hydrate in step 1 includes: {circle around (1)} cleaning and flushing the reactor by using deionized water, pouring the water into the reactor, and exhausting air from the reactor by using a vacuum pump; {circle around (2)} introducing refrigerant into the reactor, cooling the reactor to a temperature below the hydrate phase equilibrium temperature and above the freezing temperature by using a refrigeration cycle cooling system in which the reactor is placed according to the type of the refrigerant and the refrigerant hydrate phase diagram, pressurizing the reactor to the pressure point in a hydrate stabilization region corresponding to the temperature in the phase diagram after the temperature in the reactor is stabilized, and turning on a magnetic stirrer to initiate generation of the hydrate; {circle around (3)} judging whether the hydrate is initially formed through the increase of temperature in the reactor, if the temperature in the reactor suddenly increases, it is indicated that the hydrate formation reaction begins to release heat, and then if the temperature in the reactor gradually decreases until the temperature is stabilized at the original temperature within 1 h, it is indicated that a stable state is reached, and the hydrate is generated completely; measuring the temperature in the reactor by using a temperature sensor in the reactor, measuring the pressure in the reactor by using a pressure sensor, and gathering pressure and temperature signals by a data recording system and collecting same by a personal computer.

3. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein the refrigerant hydrate is a mixed liquid of one or more of tetrahydrofuran, cyclopentane and methylcyclohexane.

4. The preparation method for a hydrate energy-storage temperature-control material according to claim 2 , wherein a magnetic stirrer is present in the reactor, and the magnetic stirrer has a revolving speed of 500-600 rpm, to initiate generation of the refrigerant hydrate.

5. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein the polytetrafluoroethylene suspended ultrafine powder used in step 3 has a particle size of 2-12 μm.

6. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein the electrostatic spraying device in step 3 comprises: a storage bin ( 1 ), a coating propulsion device ( 2 ), a DC power supply ( 3 ), a nozzle ( 4 ), a conveyor belt ( 5 ) and a collection device ( 6 ), wherein the storage bin ( 1 ) is configured to internally store a spraying material, i.e. polytetrafluoroethylene suspended ultrafine powder; the coating propulsion device ( 2 ) is connected with a spraying device of the storage bin ( 1 ) and the nozzle ( 4 ) respectively; the nozzle ( 4 ) is made of a conductive material, configured to spray the polytetrafluoroethylene suspended ultrafine powder and connected with a negative electrode of the DC power supply ( 3 ), and dense negative charges are produced on the nozzle; the conveyor belt ( 5 ) of the spraying device is made of a conductive resin-based material and configured to place the hydrate particles ( 7 ), the conveyor belt ( 5 ) faces the nozzle, so that the suspended particles sprayed out from the nozzle ( 4 ) come into contact with the hydrate particles ( 7 ) to be sprayed; the conveyor belt ( 5 ) is connected with a positive electrode of the DC power supply ( 3 ), so that the hydrate particles carry positive charges, and then an electric field required for spraying is formed between the nozzle ( 4 ) and the conveyor belt ( 5 ).

7. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein a conveying speed of the conveyor belt ( 5 ) in step 3 is 0.5-2 m/s, the linear speed of spraying gas of the nozzle ( 4 ) is 100-200 m/s, the powder content of the spraying gas is 1-2 kg/m 3 , the voltage of the high-voltage electrostatic field is 60-90 kV, and the distance between the nozzle ( 4 ) and the conveyor belt is 200-300 mm.

8. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein the monomer in step (5) is a monomer solution, which is one of a dopamine methacrylamide solution with a solution concentration of 10%, a 2-hydroxyethyl methacrylate solution with a solution concentration of 30% and a glycidyl methacrylate solution with a solution concentration of 30%, wherein the evaporation temperature of the dopamine methacrylamide solution is 109-110° C., the evaporation temperature of the 2-hydroxyethyl methacrylate solution is 95° C., and the evaporation temperature of the glycidyl methacrylate solution is 67° C.

9. The preparation method for a hydrate energy-storage temperature-control material according to claim 1 , wherein a device in step 5 comprises: a throttle valve ( 8 ), a capacitance manometer ( 9 ), a gas distribution nozzle ( 10 ), a high-pressure mercury lamp ( 11 ) of ultraviolet lighting system, a water bath heating device ( 12 ), a vacuum pump ( 13 ) and a closed container ( 14 ), wherein the closed container ( 14 ) is connected to the throttle valve ( 8 ) and the capacitance manometer ( 9 ) at the inlet, to control the pressure of monomer steam entering the closed container; the closed container ( 14 ) is connected to the vacuum pump ( 13 ) at the outlet, and the gas distribution nozzle ( 10 ) is internally contained in the closed container to allow gas to be uniformly distributed in the closed container ( 14 ); the closed container is placed in the water bath heating device ( 12 ), to control the temperature in the closed container; and the high-pressure mercury lamp ( 11 ) of ultraviolet lighting system irradia

Assignees

• Univ Dalian Tech

Inventors

• Zhao Jiafei
• Song Yongchen
• Yang Mingzhao
• Dong Hongsheng
• Zhang Lunxiang
• Shi Quan
• Yang Lei
• Ling Zheng
• Sun Xiang
• Li Yanghui
• Liu Weiguo

Classifications

• B05B5/081 Primary

  specially adapted for treating particulate materials · CPC title

• B05B5/084

  the objects lying on, or being supported above conveying means, e.g. conveyor belts · CPC title

• B05D1/06

  Applying particulate materials · CPC title

• C09K5/063 Primary

  Materials absorbing or liberating heat during crystallisation; Heat storage materials · CPC title

• C09K5/066 Primary

  Cooling mixtures; De-icing compositions · CPC title