Radiation thermal absorber based on characteristic absorption spectrum, and stirling engine and operation method thereof

Patent metadata

Field	Value
Publication number	US-10167812-B2
Application number	US-201715617620-A
Country	US
Kind code	B2
Filing date	Jun 8, 2017
Priority date	Aug 8, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A radiation thermal absorber based on characteristic absorption spectrum, a Stirling engine and an operation method thereof. The radiation thermal absorber allows working gas in the Stirling engine to absorb radiation heat quickly, and help the Stirling engine adopt assistant heating to ensure steady operation when solar power is not enough. The radiation thermal absorber includes a heater base, a radiation energy conversion device, heating tubes, a combustion chamber and valves of the heating tubes. The radiation energy conversion device converts the solar energy into radiation energy near a characteristic absorption peak of the working gas, and the working gas absorbs the radiation directly in depth.

First claim

The invention claimed is:

1. A radiation thermal absorber based on characteristic absorption spectrum, comprising:
a heater base,
a radiation energy conversion device positioned on an upper end of the heater base and of an expansion chamber of a Stirling engine,
heating tubes,
a combustion chamber located around the heating tubes and providing heat needed by the heating tubes, and
valves connected to the heating tubes and to the heater base, wherein the heater base has a first pore structure, a second pore structure, and a third pore structure, the second pore structure is positioned on a connection place between the heater base and the expansion chamber, the first pore structure is positioned on a connection place between the heater base and a regenerator, and the third pore structure is positioned on a connection place between the expansion chamber and the regenerator and is close to an upper surface of the heater base,
wherein the radiation energy conversion device is made from semiconductor or metal, and includes a radiation receiver, an intermediate layer and a radiation emitter, the radiation receiver absorbs concentrated solar radiation and converts the concentrated solar radiation into thermal energy, the intermediate layer transports the thermal energy to the radiation emitter, and the radiation emitter emits radiant energy distributed in a vicinity of a characteristic absorption peak of a working gas to heat the working gas in the expansion chamber directly; and wherein the radiant energy distributed in the vicinity of the characteristic absorption peak of the working gas has a same center wavelength of radiation spectrum with the characteristic absorption peak of the working gas, and has a narrower spectral line width than that of the characteristic absorption peak of the working gas.

2. The radiation thermal absorber based on characteristic absorption spectrum according to claim 1 , wherein the working gas of the radiation thermal absorber based on characteristic absorption spectrum includes one or more of carbon dioxide, butane, and butene.

3. The radiation thermal absorber based on characteristic absorption spectrum according to claim 1 , wherein the third pore structure is normally open; the first pore structure and the second pore structure have opening and closing states that are controlled by the valves of the heating tubes; wherein size of pores of the first pore structure and the second pore structure are controlled by controlling the valves of the heating tubes when the first pore structure and the second pore structure are open, thus a flow ratio of the working gas through the heating tubes and the third pore structure is controlled.

4. The radiation thermal absorber based on characteristic absorption spectrum according to claim 1 , wherein the heating tubes are evenly arranged along a circumference of the heater base; each heating tube is bent into two sections in a three-dimensional curve form; and the working gas enters one end of the heating tubes through the second pore structure from the expansion chamber, and enters the regenerator through the first pore structure from another end of the heating tubes when the first pore structure and the second pore structure are both open.

5. The radiation thermal absorber based on characteristic absorption spectrum according to claim 1 , further comprising a solar radiation heat source, which is implemented by a solar concentrator system comprising a compound parabolic concentrator (CPC concentrator.

6. A Stirling engine comprising:
an expansion chamber;
a compression chamber;
a regenerator;
a radiation thermal absorber based on characteristic absorption spectrum, the absorber comprising:
a heater base,
a radiation energy conversion device positioned on an upper end of the heater base and of the expansion chamber,
heating tubes,
a combustion chamber located around the heating tubes and providing heat needed by the heating tubes, and
valves connected to the heating tubes and to the heater base, wherein the heater base has a first pore structure, a second pore structure, and a third pore structure, the second pore structure is positioned on a connection place between the heater base and the expansion chamber, the first pore structure is positioned on a connection place between the heater base and the regenerator, and the third pore structure is positioned on a connection place between the expansion chamber and the regenerator and is close to an upper surface of the heater base; and

a cooler,
wherein the radiation thermal absorber is connected to one end of the regenerator; the other end of the regenerator is connected to the cooler; an exit of the cooler is connected to the compression chamber; an exit of the radiation thermal absorber is connected to the expansion chamber; and the expansion chamber, the radiation thermal absorber, the regenerator, the cooler and the compression chamber form a complete circuit, and working gas flows through the circuit, and
wherein the radiation energy conversion device is made from semiconductor or metal, and includes a radiation receiver, an intermediate layer and a radiation emitter, the radiation receiver absorbs concentrated solar radiation and converts the concentrated solar radiation into thermal energy, the intermediate layer transports the thermal energy to the radiation emitter, and the radiation emitter emits radiant energy distributed in a vicinity of a characteristic absorption peak of the working gas to heat the working gas in the expansion chamber directly; and wherein the radiant energy distributed in the vicinity of the characteristic absorption peak of the working gas has a same center wavelength of radiation spectrum with the characteristic absorption peak of the working gas, and has a narrower spectral line width than that of the characteristic absorption peak of the working gas.

7. The Stirling engine according to claim 6 , further comprising:
an expansion chamber piston;
a compression chamber piston;
a flywheel; and
a dynamo;
wherein the expansion chamber and the compression chamber are connected to the expansion chamber piston and the compression chamber piston, respectively, and adopt an expansion chamber piston ring and a compression chamber piston ring to separate the working gas in the expansion chamber and the compression chamber from environment, respectively; the expansion chamber piston and the compression chamber piston are connected to a transmission structure through an expansion chamber piston rod and a compression chamber piston rod, respectively; and the transmission structure is connected to one end of the flywheel;
and the other end of the flywheel is connected to the dynamo.

8. A method comprising:
operating a Stirling engine comprising:
an expansion chamber;
a compression chamber;
a regenerator;
a radiation thermal absorber based on characteristic absorption spectrum, the absorber comprising:
a heater base,
a radiation energy conversion device positioned on an upper end of the heater base and of the expansion chamber,
heating tubes,
a combustion chamber located around the heating tubes and providing heat needed by the heating tubes, and
valves connected to the heating tubes and to the heater base, wherein the heater base has a first pore structure, a second pore structure, and a third pore structure, the second pore structure is positioned on a connection place between the heater base and the expansion chamber, the first pore structure is positioned on a connection place between the heater base and the regenerator, and the third pore structure is positioned on a connection place between the expansion chamber and the regenerator and is close to an upper surface of the heater base; and

Assignees

• Univ Zhejiang

Inventors

• Xiao Gang
• Qiu Min
• Ni Mingjiang
• Li Qiang
• Wang Shulin
• Luo Zhongyang
• Cen Kefa

Classifications

• F03G6/068

  having other power cycles, e.g. Stirling or transcritical, supercritical cycles; combined with other power sources, e.g. wind, gas or nuclear · CPC title

• F24S90/00

  Solar heat systems not otherwise provided for · CPC title

• F02G2254/30

  using solar radiation · CPC title

• F02G1/055 Primary

  Heaters or coolers · CPC title

• F02G2270/90

  Valves · CPC title