CN220415480U

CN220415480U - Rankine cycle system for combined use of solar energy and LNG cold energy

Info

Publication number: CN220415480U
Application number: CN202322252667.8U
Authority: CN
Inventors: 袁鑫; 陈衡; 李·萨仁高娃; 潘佩媛; 王修彦; 徐钢
Original assignee: North China Electric Power University
Current assignee: North China Electric Power University
Priority date: 2023-08-22
Filing date: 2023-08-22
Publication date: 2024-01-30
Anticipated expiration: 2033-08-22

Abstract

The utility model relates to a Rankine cycle system for combined use of solar energy and LNG cold energy, which comprises: a Rankine cycle system, a solar heat collection system, a steam turbine, a pump and the like. The LNG is heated twice and then enters the turbine to apply work, the thermal working medium at the outlet of the solar heat collection field is divided into two parts, one part of the thermal working medium transfers heat to the Rankine cycle working medium, the other part of the thermal working medium is used for heating the LNG, the Rankine cycle working medium absorbs heat energy in the thermal working medium at the outlet of the solar heat collection field and then enters the turbine to apply work, and then enters the heat exchanger to exchange heat with the LNG to realize condensation, so that solar heat utilization and LNG cold energy utilization are realized. In conclusion, the whole system realizes gradient utilization of LNG cold energy, utilizes the thermal working medium in the solar heat collection field to heat the Rankine cycle working medium and the LNG, and realizes heat utilization of solar energy.

Description

Rankine cycle system for combined use of solar energy and LNG cold energy

Technical Field

The utility model belongs to the technical field of LNG cold energy utilization, and particularly relates to a Rankine cycle system for combined use of solar energy and LNG cold energy.

Background

Natural Gas (NG) is widely used worldwide as a green energy source, when in ocean transportation, natural gas is firstly dehydrated, desulfurized and processed at low temperature to become Liquefied Natural Gas (LNG) which is stored in a liquid storage tank, the storage condition of the LNG is 162 ℃ and 14mpa, when in use, the LNG needs to be gasified to normal temperature, a large amount of cold energy is released in the process, about 830-860kJ/kg, the cold energy is usually consumed by sea water or air in a gasification station, energy waste and environmental pollution are caused, and if the cold energy is utilized, huge economic benefits can be generated.

The prior LNG cold energy utilization modes can be divided into direct utilization, indirect utilization and cascade utilization, wherein the direct utilization comprises methods of air separation, low-temperature power generation, low-temperature refrigeration houses and the like, the indirect utilization comprises methods of low-temperature crushing and the like, and the cascade utilization is to comprehensively use the process by dividing temperature segments so as to fully utilize the LNG cold energy. In the LNG cold energy utilization method at present, the cold energy power generation application is more, the technology is mature, and compared with the application of the cold energy to other technologies such as air separation, low-temperature refrigeration houses and the like, the cold energy power generation method has the advantages that the occupied area is small, the generated electric energy can be supplied to a power grid, and the downstream control is avoided. The cold energy power generation method mainly comprises natural gas direct expansion, low-temperature Rankine cycle, low Wen Bulei ton cycle, multistage combined cycle and compound cycle. The direct expansion method cannot fully utilize LNG low-temperature cold energy, and the cold energy utilization rate is low; the brayton cycle method, the multi-stage cycle and the compound cycle are more complex in equipment operation or system, and the practical application is less; the low-temperature Rankine cycle method has simple flow and good flexibility, so most of cold energy power generation devices adopt the flow.

Through the combined utilization of LNG cold energy, rankine cycle and solar energy, not only can provide sufficient heat source of LNG cold energy gasification process, can also utilize solar energy, realize the high energy complementary utilization of solar energy and LNG cold energy.

Disclosure of Invention

The utility model aims to provide a Rankine cycle system for combined use of solar energy and LNG cold energy, which is characterized by mainly comprising a Rankine cycle system, a solar heat collection system, a steam turbine, a pump and the like, wherein a thermal working medium in the solar heat collection system is used as a heat source of the Rankine cycle, LNG is used as a cold source of the Rankine cycle, and high-energy complementary utilization of the solar energy and the LNG cold energy is realized.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the LNG is pressurized by a pump and enters a heat exchanger to transfer cold energy to a Rankine cycle working medium, part of the cold energy is released, and then enters the heat exchanger to exchange heat with a thermal working medium in a solar heat collection system, gasifies and heats, and finally enters a turbine to do work.

The Rankine cycle working medium is pressurized by a pump, enters a heat exchanger to absorb heat of the working medium in a solar heat collection system and evaporate, then enters a turbine to do work, and the working medium after doing work enters the heat exchanger to absorb cold energy of LNG and condense, and finally enters the pump again to complete circulation.

The heat working medium in the solar heat collection system enters the storage tank after being heated in the solar heat collection field, the heat working medium at the outlet of the storage tank is divided into two parts, one part of the heat working medium enters the heat exchanger to transfer heat to the Rankine cycle working medium and then is pumped back to the solar heat collection field to complete circulation, and the other part of the heat working medium enters the heat exchanger to transfer heat to LNG and then is pumped back to the solar heat collection field to complete circulation.

The beneficial effects of the utility model are as follows:

the utility model provides a Rankine cycle system for combined use of solar energy and LNG cold energy, which is a novel LNG cold energy utilization system. The system consists of a Rankine cycle system, a solar heat collection system, a steam turbine and a pump.

According to the utility model, the Rankine cycle is adopted to absorb part of LNG cold energy, the LNG is gasified and heated by utilizing solar energy, and then the LNG is introduced into the turbine to do work, so that the gradient utilization of the LNG cold energy is realized.

In addition, the thermal working medium in the solar heat collection system is used as a heat source of the Rankine cycle, and the LNG is used as a cold source of the Rankine cycle, so that the high-energy complementary utilization of solar energy and LNG cold energy is realized.

Drawings

Fig. 1 is a schematic diagram of a rankine cycle system for combined use of solar energy and LNG cold energy.

In the figure: 1-1# pump; 2# 1 heat exchange; a 3-2# heat exchanger; a turbine No. 4-1; 5-2# pump; a 6-3# heat exchanger; 7-2# turbine; 8-a solar thermal collection field; 9-a storage tank; 10-3# pump

Detailed Description

The present utility model provides a rankine cycle system for the combined use of solar energy and LNG cold energy, and the following description of the principles of operation of the system in conjunction with the accompanying drawings and detailed description will be given with the emphasis instead being placed on the following description by way of example only and not on the limitation of the scope and application of the utility model.

Fig. 1 is a schematic diagram of a rankine cycle system for combined use of solar energy and LNG cold energy. The LNG compression type solar heat collection system is characterized in that LNG enters the 1# heat exchanger 2 to transfer cold energy to a Rankine cycle working medium after being compressed by the 1# pump 1, enters the 2# heat exchanger 3 to exchange heat with a hot working medium in a solar heat collection system and gasify and heat up after releasing part of the cold energy, and finally enters the 1# turbine 4 to do work.

The Rankine cycle working medium is pressurized by a No. 2 pump 5 and then enters a No. 3 heat exchanger 6 to absorb heat of the working medium in a solar heat collection system and evaporate, then enters a No. 2 turbine 7 to do work, the working medium after doing work enters a No. 1 heat exchanger 2 to absorb cold energy of LNG and condense, and finally enters the No. 2 pump 5 again to complete circulation.

The heat working medium in the solar heat collection system enters the storage tank 9 after being heated in the solar heat collection field 8, the heat working medium at the outlet of the storage tank is divided into two parts, one part of the heat working medium enters the 3# heat exchanger 6 to transfer heat to the Rankine cycle working medium and then returns to the solar heat collection field 8 through the 3# pump 10 to complete circulation, and the other part of the heat working medium enters the 2# heat exchanger 3 to transfer heat to LNG and then returns to the solar heat collection field 8 through the 3# pump 10 to complete circulation.

The present utility model is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present utility model are intended to be included in the scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. The Rankine cycle system combining solar energy and LNG cold energy mainly comprises a 1# pump (1), a 1# heat exchanger (2), a 2# heat exchanger (3), a 1# turbine (4), a 2# pump (5), a 3# heat exchanger (6), a 2# turbine (7), a solar heat collection field (8), a storage tank (9) and a 3# pump (10), and is characterized in that LNG is pressurized by the 1# pump (1) and then sequentially gasified and heated by the 1# heat exchanger (2) and the 2# heat exchanger (3), and then enters the 1# turbine (4) to do work; the solar heat collection field (8) is connected with the storage tank (9); the hot working medium at the outlet of the storage tank (9) is divided into two streams, one stream sequentially passes through the No. 3 heat exchanger (6) and the No. 3 pump (10) and then returns to the solar heat collection field (8) to complete circulation, and the other stream sequentially passes through the No. 2 heat exchanger (3) and the No. 3 pump (10) and then returns to the solar heat collection field (8) to complete circulation; in the Rankine cycle, working medium is pressurized by a No. 2 pump (5) and then enters a No. 3 heat exchanger (6) to absorb heat and evaporate, then enters a No. 2 turbine (7) to do work and then enters a No. 1 heat exchanger (2) to condense, and finally enters the No. 2 pump (5) to complete the cycle.

2. The Rankine cycle system for combined use of solar energy and LNG cold energy according to claim 1 is characterized in that LNG is pressurized by a No. 1 pump (1) and enters a No. 1 heat exchanger (2) to transfer cold energy to a Rankine cycle working medium, then enters a No. 2 heat exchanger (3) to be gasified and heated, and then enters a No. 1 turbine (4) to do work.

3. A rankine cycle system for combined use of solar energy and LNG cold energy according to claim 1, characterized in that the solar thermal-arrest field (8) is connected to the storage tank (9) for coping with various emergency situations.

4. The Rankine cycle system for combined use of solar energy and LNG cold energy according to claim 1, wherein the hot working medium at the outlet of the storage tank (9) is divided into two streams, one stream enters the No. 3 heat exchanger (6) to heat the Rankine cycle working medium, and the other stream enters the No. 2 heat exchanger (3) to gasify and heat the LNG.

5. The rankine cycle system for combined use of solar energy and LNG cold energy according to claim 1, wherein the thermal working medium in the solar heat collection system is used as a heat source and LNG is used as a cold source.