CN117804097A - A carbon dioxide transcritical ultra-high temperature heat pump system - Google Patents

Abstract

The invention belongs to the field of high temperature heat pumps, and discloses a carbon dioxide transcritical ultra-high temperature heat pump system, which comprises: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit which are coupled through heat exchange of an air cooler; the heat pump circulation unit comprises a heat regenerator, an air cooler, a compressor unit, an expander and an evaporator; the heat release side outlet of the first air cooler is connected with the inlet of the expander, one end of the evaporator is connected with the outlet of the expander, and the other end of the evaporator is connected with the heat release side inlet of the first air cooler through the compressor unit; the flash steam supply unit includes: a booster pump, flash tank and vapor compressor; the booster pump is connected with a water inlet of the flash tank through the heat absorption side of the first air cooler; the water outlet of the flash tank is connected with the water inlet of the booster pump; the air outlet of the flash tank is communicated with the air inlet of the vapor compressor. The technical scheme of the invention can improve the heating temperature and the heat utilization rate of the heat pump, can flexibly configure steam, reduces heat exchange loss and improves the performance of a heat pump system.

Description

A carbon dioxide transcritical ultra-high temperature heat pump system

Technical field

The invention belongs to the field of high-temperature heat pumps, and in particular relates to a carbon dioxide transcritical ultra-high temperature heat pump system.

Background technique

In industrial production, high-temperature steam is widely used, including drying, sterilization, disinfection and distillation processes in food processing, papermaking, wood, brewing and chemical industries. High-temperature steam is in great demand in industrial processes. Traditional steam production methods are mainly coal boilers, gas boilers and electric boilers, with low energy efficiency and high pollutant and carbon emissions. Heat pumps can consume a small amount of electricity or thermal energy to transfer heat from low-grade heat sources to high-grade heat sources. They are efficient, environmentally friendly and stable, and can replace boilers to supply steam.

Compared with traditional refrigerants, carbon dioxide (CO2) has the advantages of excellent environmental performance, safe, non-toxic, non-flammable, easy to obtain, low price and low critical point. It is a natural excellent refrigerant. In addition, CO2 has the characteristics of high density and high heat transfer coefficient, which can significantly reduce the size of compressors, heat exchangers and other equipment. Existing CO2 transcritical cycles are commonly used in hot water heating, district heating, heating in severe cold areas, automobile air conditioning, cold storage refrigeration and other fields.

For high-temperature heat pumps with ultra-high parameters such as large pressure ratios and large temperature rises, there are great challenges in the aerodynamic design, sealing structure, equipment manufacturing and operation control of the compressor. Existing high-temperature heat pumps use multi-stage compression technology or cascade heat pumps to solve the problem of high pressure ratio. A high-pressure ratio high-temperature heat pump system requires at least three stages of compression, complex operation control, and high compressor temperature, which greatly reduces its efficiency. The cascade heat pump couples two or more simple heat pump cycles (different refrigerants) to reduce the single-stage pressure ratio, but it has problems such as complex structure, high cost, and complex control strategies. In comparison, the CO2 transcritical heat pump pressure ratio is small, the compressor efficiency is high, and the system is relatively simple. The existing CO2 heat pump has the limitation that the pressure difference between the air cooler and the evaporator is large, the throttling loss is large, and the performance of the heat pump system cannot be further improved.

The existing transcritical carbon dioxide heat pump technology has the following problems:

(1) Existing carbon dioxide heat pumps are mostly used for hot water heating, regional heating and drying. The heating temperature is low and steam cannot be directly produced. The higher the operating temperature, the faster the performance efficiency declines;

(2) The air cooler is suitable for sensible heat heating with large temperature differences and is used to directly produce steam. The thermal matching of temperature slip is poor and the heat exchange loss is large. It does not comply with the principle of energy cascade utilization and the heat utilization efficiency needs to be improved;

(3) The pressure difference between the air cooler and the evaporator of the carbon dioxide heat pump is large, and the throttling loss of the expansion valve is large, so there is still room for improvement in system performance.

Summary of the invention

The purpose of the present invention is to provide a carbon dioxide transcritical ultra-high temperature heat pump system to solve the above-mentioned problems existing in the prior art.

As a first aspect, the present invention provides a carbon dioxide transcritical ultra-high temperature heat pump system, including:

Transcritical carbon dioxide heat pump cycle unit;

The transcritical carbon dioxide heat pump cycle unit includes a first air cooler, a regenerator, a compressor unit, an expander and an evaporator; the heat release side outlet of the first air cooler is subcooled by the regenerator side is connected to the inlet of the expander, the evaporator inlet is connected to the outlet of the expander, and the outlet of the evaporator is connected to the inlet of the compressor unit through the superheated side of the regenerator, so The compressor unit is also connected to the heat release side inlet of the first air cooler.

A flash steam supply unit, wherein the flash steam supply unit is heat exchange coupled with the transcritical carbon dioxide heat pump circulation unit through the first air cooler; the flash steam supply unit comprises: a booster pump, a flash tank and a steam compressor; the booster pump is connected to the water inlet of the flash tank through the heat absorption side of the first air cooler; the water outlet of the flash tank is connected to the water inlet of the booster pump; the air outlet of the flash tank is connected to the air inlet of the steam compressor.

Optionally, the compressor unit includes a first compressor and a second compressor;

The outlet of the first compressor is connected to the inlet of the second compressor, and the inlet of the first compressor is connected to the outlet of the evaporator through the superheat side of the regenerator. The second compressor The outlet of the machine is connected to the heat release side of the first air cooler.

As a second aspect, the present invention provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit coupled by heat exchange of a first air cooler;

The transcritical carbon dioxide heat pump cycle unit includes a first air cooler, a regenerator, a compressor unit, an expander and an evaporator; the heat release side outlet of the first air cooler is subcooled by the regenerator side is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the heat release side inlet of the first air cooler through the compressor unit; the heat release side outlet of the first air cooler is also It is connected to the inlet of the expander, and the outlet of the expander is connected to the heat release side inlet of the first air cooler through the compressor unit;

The flash steam supply unit includes: a booster pump, a flash tank and a steam compressor;

The booster pump is connected to the water inlet of the flash tank through the heat absorption side of the first air cooler; the water outlet of the flash tank is connected to the water inlet of the booster pump; the flash tank The air outlet of the steam tank is connected to the air inlet of the steam compressor.

Optionally, the compressor unit includes a first compressor and a second compressor;

The outlet of the first compressor is connected to the inlet of the second compressor, and the inlet of the first compressor passes through the superheat side of the regenerator and is connected to the outlet of the evaporator and the outlet of the expander. connection, the outlet of the second compressor is connected to the heat release side of the first air cooler.

As a third aspect, the present invention provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump cycle unit and a flash steam supply unit coupled by heat exchange of a first air cooler;

The transcritical carbon dioxide heat pump circulation unit includes a first air cooler, a regenerator, an expander, an evaporator, a first compressor and a second compressor;

The heat release side outlet of the first air cooler is connected to the inlet of the expander through the subcooling side of the regenerator, and the outlet of the expander is connected to the inlet of the evaporator. The outlet of the first compressor is connected to the inlet of the first compressor. The outlet of the first compressor is connected to the inlet of the second compressor through the superheat side of the regenerator. The outlet of the second compressor is connected to the inlet of the second compressor. The heat release side of the first air cooler;

The flash steam supply unit includes: a booster pump, a flash tank and a steam compressor;

The booster pump is connected to the water inlet of the flash tank through the heat absorption side of the first air cooler; the water outlet of the flash tank is connected to the water inlet of the booster pump; the air outlet of the flash tank is connected to the air inlet of the steam compressor.

As a fourth aspect, the present invention provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit coupled by heat exchange of an air cooler unit;

The transcritical carbon dioxide heat pump cycle unit includes an air cooler unit, a regenerator, a first compressor, a second compressor, an expander and an evaporator; the air cooler unit passes through the subcooling side of the regenerator Connected to the inlet of the expander; the outlet of the evaporator is connected to the air cooler unit through the superheat side of the regenerator;

The air cooler unit includes a first air cooler and a second air cooler, the first air cooler is connected to the second air cooler through the second compressor; the second air cooler passes through The subcooling side of the regenerator is connected to the inlet of the expander; the first air cooler is connected to the superheated side of the regenerator through the first compressor;

The flash steam supply unit includes: a booster pump, a flash tank and a steam compressor;

The booster pump is connected to the water inlet of the flash tank through the heat absorption side of the first air cooler and the second air cooler; the water outlet of the flash tank is connected to the booster pump. The water inlet of the pressure pump is connected; the air outlet of the flash tank is connected with the air inlet of the steam compressor.

The technical effects of the present invention are:

(1) The present invention makes full use of the large temperature slip characteristics of heat exchange in the air cooler to increase the heating temperature of the heat pump, enhance the thermal matching performance of the air cooler, and reduce heat exchange losses;

(2) The present invention uses multi-stage flash evaporation in the flash steam supply circuit to reduce throttling flash evaporation losses and efficiently and flexibly supply steam at different temperatures;

(3) The present invention uses a steam compressor to recompress the flashed saturated steam, and introduces cold water to offset the superheating effect of compression, so that steam of different temperatures and pressures can be supplied more flexibly;

(4) The present invention uses a regenerator in the carbon dioxide heat pump cycle to efficiently utilize the working fluid with a higher temperature after the air cooler releases heat to increase the temperature before compression and improve the performance of the heat pump system;

(5) The present invention uses an expander instead of a throttle valve in the carbon dioxide heat pump cycle to recover energy from the expansion process, reduce throttling losses, and improve the performance of the heat pump system.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the drawings of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

The drawings that form a part of this application are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation of this application. In the attached picture:

Figure 1 is a schematic structural diagram of the first circulation system in the embodiment of the present invention;

FIG2 is a schematic diagram of the structure of a second circulation system in an embodiment of the present invention;

Figure 3 is a schematic structural diagram of the third circulation system in the embodiment of the present invention;

FIG4 is a schematic structural diagram of a fourth circulation system in an embodiment of the present invention;

FIG5 is a schematic diagram of the structure of a fifth circulation system in an embodiment of the present invention;

Label description: 1-first compressor, 2-second compressor, 3-first air cooler, 4-evaporator, 5-expander, 6-booster pump, 7-flash tank, 8-steam Compressor, 9-regenerator, 10-second air cooler.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, Embodiments, and all other embodiments obtained by those of ordinary skill in the art without creative efforts, fall within the scope of protection of the present invention.

To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

Note that when an element is said to be "anchored" to another element, it can be directly on the other element or intervening elements may also be present. When an element is said to be "connected" to another element, it can be is directly connected to another element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only;

The terms "includes," "includes," "has," "contains," etc. used in this article are all open terms, meaning including but not limited to.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field of the invention. The terms used herein in the description of the invention are only for describing specific embodiments. For purposes of the invention, and not as a limitation of the invention, the term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

Embodiment 1

As shown in Figure 1, this embodiment provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump circulation unit;

The transcritical carbon dioxide heat pump cycle unit includes a first air cooler 3, a regenerator 9, a compressor unit, an expander 5 and an evaporator 4; the heat release side outlet of the first air cooler 3 passes through the regenerator. The subcooling side of the heater 9 is connected to the inlet of the expander 5 , the inlet of the evaporator 4 is connected to the outlet of the expander 5 , and the outlet of the evaporator 4 passes through the overheated side of the regenerator 9 It is connected with the inlet of the compressor unit, and the compressor unit is also connected with the heat release side inlet of the first air cooler 3 .

It also includes a flash steam supply unit, which is thermally coupled to the transcritical carbon dioxide heat pump cycle unit through the first air cooler 3;

The flash steam supply unit includes: booster pump 6, flash tank 7 and steam compressor 8;

The booster pump 6 is connected to the water inlet of the flash tank 7 through the heat absorption side of the first air cooler 3; the water outlet of the flash tank 7 is connected to the water inlet of the booster pump 6 Connection; the air outlet of the flash tank 7 is connected to the air inlet of the steam compressor 8 .

It can be implemented that the compressor unit includes a first compressor 1 and a second compressor 2;

The outlet of the first compressor 1 is connected to the inlet of the second compressor 2, and the inlet of the first compressor 1 is connected to the outlet of the evaporator 4 through the superheat side of the regenerator 9, The outlet of the second compressor 2 is connected to the heat release side of the first air cooler 3 .

This embodiment proposes a new type of carbon dioxide transcritical ultra-high temperature heat pump system, which combines transcritical carbon dioxide cycle, flash steam recompression, expansion work recovery and high-efficiency heat recovery to improve heating temperature and heat matching performance and reduce throttling. loss, improve system performance, and can be used to produce high-temperature water, high-temperature steam, high-temperature air, etc. Reducing throttling losses through the expander and efficient heat recovery through the regenerator can improve system performance; the carbon dioxide cycle is coupled with the flash evaporation circuit to reduce heat loss, and the large temperature slip of the air cooler is used to increase the heating temperature and produce Output steam; through the combination of flash evaporation technology and steam compressor, steam can be flexibly configured, and the multi-stage flash evaporation in the flash tank can efficiently produce steam;

The following takes industrial high-temperature steam supply as an example to describe the specific implementation of this embodiment for high-temperature heating. As shown in Figure 1, this embodiment includes a transcritical carbon dioxide heat pump cycle and a flash steam supply loop. The transcritical carbon dioxide heat pump cycle mainly includes a regenerator, compressor 1, compressor 2, air cooler, regenerator, expander and evaporator. The low-pressure and low-temperature working fluid enters the regenerator and is heated up into superheated steam, which is compressed to an intermediate pressure by compressor 1. It enters compressor 2 and is compressed into a high-temperature and high-pressure working fluid. The high-temperature and high-pressure working fluid enters the air cooler and heats the pressurized water in the flash steam supply circuit. The temperature of the working fluid decreases and becomes a high-pressure and medium-temperature working fluid. The water side inlet temperature of the air cooler is higher, so the temperature of the working fluid leaving the air cooler is higher. In order to make full use of the waste heat of the working fluid, a recuperator is set up, and the waste heat of the working fluid at the outlet of the air cooler is used to heat the low-temperature working fluid at the outlet of the evaporator to improve system performance. The high-pressure working fluid leaving the air cooler heats the low-temperature working fluid in the regenerator, and the temperature decreases, becoming a high-pressure and low-temperature working fluid. In order to reduce throttling losses, an expander is used to recover expansion work. The internal energy of the working fluid is converted into the mechanical work output of the expander. The temperature and pressure of the working fluid drop, becoming a low-temperature and low-pressure two-phase working fluid, which enters the evaporator to absorb the low-temperature heat source W1. The heat evaporates into saturated steam and returns to the starting point of the cycle.

The flash steam supply loop mainly includes a booster pump, flash tank and steam compressor. The carbon dioxide working fluid in the air cooler releases sensible heat. If the cold water is directly heated to produce steam, the irreversible loss in the heat exchange process will be huge. The thermal matching performance of the hot and cold fluids is poor, and the large temperature slip of the working fluid in the air cooler cannot be used. characteristic. Therefore, the air cooler heats the flashed pressurized water to a high temperature, and produces low-pressure steam through the flash tank, and the steam is then used by the compressor to produce steam of different pressures. The carbon dioxide heat pump is coupled with the flash evaporation system through an air cooler to reduce heat exchange losses in the air cooler.

The process of the flash steam supply circuit: the pressurized water after the booster pump is heated in the air cooler and becomes high-temperature pressurized water. The mixed high-temperature pressurized water enters the flash tank for throttling and flash evaporation, and is divided into two paths: low-pressure saturated water and low-pressure saturated steam. The saturated water mixes with the supplementary water source W3 in the loop, then enters the booster pump to boost pressure and returns to the starting point. The saturated steam enters the steam compressor and is compressed, providing low-temperature water source W4 to eliminate the superheating effect of the compression process, and becomes steam of different temperatures and pressures. During the flash evaporation process, high-temperature pressurized water is directly throttled and flashed to low pressure, resulting in greater throttling losses. Multi-stage flash evaporation technology is used in the loop. Through step-by-step depressurization and throttling flash evaporation at different pressures, multiple channels of saturated water and saturated steam are generated. The saturated water from the upper level is supplied to the next level of flash evaporation, which can reduce losses and increase steam. Yield. The multiple streams of saturated steam generated by flash evaporation are flexibly configured according to industrial needs. When a single steam is required, it is compressed to the same pressure and combined together to increase the steam supply; when steam of different pressures is required, the steam is provided separately.

Embodiment 2

As shown in Figure 2, this embodiment provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit coupled through heat exchange of the first air cooler 3;

The transcritical carbon dioxide heat pump cycle unit includes a first air cooler 3, a regenerator 9, a compressor unit, an expander 5 and an evaporator 4; the heat release side outlet of the first air cooler 3 passes through the regenerator. The subcooling side of the heater 9 is connected to the inlet of the evaporator 4, and the outlet of the evaporator 4 is connected to the heat release side inlet of the first air cooler 3 through the compressor unit; the first The heat release side outlet of the air cooler 3 is also connected to the inlet of the expander 5, and the outlet of the expander 5 is connected to the heat release side inlet of the first air cooler 3 through the compressor unit;

The flash steam supply unit includes: booster pump 6, flash tank 7 and steam compressor 8;

The booster pump 6 is connected to the water inlet of the flash tank 7 through the heat absorption side of the first air cooler 3; the water outlet of the flash tank 7 is connected to the water inlet of the booster pump 6 Connection; the air outlet of the flash tank 7 is connected to the air inlet of the steam compressor 8 .

It can be implemented that the compressor unit includes a first compressor 1 and a second compressor 2;

The outlet of the first compressor 1 is connected to the inlet of the second compressor 2 , the inlet of the first compressor 1 is connected to the outlet of the evaporator 4 and the outlet of the expander 5 through the superheating side of the regenerator 9 , and the outlet of the second compressor 2 is connected to the heat release side of the first air cooler 3 .

In the transcritical carbon dioxide heat pump cycle, the working fluid leaving the air cooler can be divided into two streams, as shown in Figure 2. Specific implementation process: The working fluid leaving the air cooler is divided into two flows. One flow directly enters the expander to recover work. The pressure and temperature are reduced, and is directly mixed with the working fluid at the evaporator outlet and enters the regenerator. Another flow enters the regenerator and releases heat, reducing the flow rate and improving the matching of hot and cold fluids, which is beneficial to reducing the heat exchange loss of the regenerator. The implementation process of the rest of this embodiment is the same as that of Embodiment 1.

Embodiment 3

As shown in Figure 3, this embodiment provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit coupled through heat exchange of the first air cooler 3;

The transcritical carbon dioxide heat pump cycle unit includes a first air cooler 3, a regenerator 9, an expander 5, an evaporator 4, a first compressor 1 and a second compressor 2;

The heat release side outlet of the first air cooler 3 is connected to the inlet of the expander 5 through the subcooling side of the regenerator 9, the outlet of the expander 5 is connected to the inlet of the evaporator 4, the outlet of the evaporator 4 is connected to the inlet of the first compressor 1, the outlet of the first compressor 1 is connected to the inlet of the second compressor 2 through the superheating side of the regenerator 9, and the outlet of the second compressor 2 is connected to the heat release side of the first air cooler 3;

The flash steam supply unit includes: booster pump 6, flash tank 7 and steam compressor 8;

The booster pump 6 is connected to the water inlet of the flash tank 7 through the heat absorption side of the first air cooler 3; the water outlet of the flash tank 7 is connected to the water inlet of the booster pump 6 Connection; the air outlet of the flash tank 7 is connected to the air inlet of the steam compressor 8 .

In the transcritical carbon dioxide heat pump cycle, the regenerator can be arranged between the first compressor 1 and the second compressor 2 to improve the thermal matching performance of the hot and cold fluids in the regenerator, as shown in Figure 3. Specific implementation process: The low-temperature and low-pressure working fluid after the evaporator is compressed to an intermediate pressure in the first compressor 1, at which time the temperature is relatively low, and enters the regenerator to exchange heat with the high-temperature and high-pressure working fluid after the air cooler. The working fluid temperature increases, which can improve the heat exchange temperature difference between the hot and cold fluids in the regenerator, improve thermal matching performance, and reduce heat exchange losses. The medium-pressure working fluid enters the second compressor 2, is compressed to high temperature and high pressure, and enters the air cooler to release heat. The implementation process of the rest of this embodiment is the same as that of Embodiment 1.

Embodiment 4

As shown in FIG4 , this embodiment provides a carbon dioxide transcritical ultra-high temperature heat pump system, comprising: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit coupled by heat exchange of an air cooler unit;

The transcritical carbon dioxide heat pump cycle unit includes an air cooler unit, a regenerator 9, a first compressor 1, a second compressor 2, an expander 5 and an evaporator 4; the air cooler unit passes the heat regenerator The subcooling side of the evaporator 9 is connected to the inlet of the expander 5; the outlet of the evaporator 4 is connected to the air cooler unit through the superheated side of the regenerator 9;

The air cooler unit includes a first air cooler 3 and a second air cooler 10. The first air cooler 3 is connected to the second air cooler 10 through the second compressor 2; The air cooler 10 is connected to the inlet of the expander 5 through the subcooling side of the regenerator 9; the first air cooler 3 passes through the superheat of the first compressor 1 and the regenerator 9 side connection;

The flash steam supply unit includes: booster pump 6, flash tank 7 and steam compressor 8;

The booster pump 6 is connected to the water inlet of the flash tank 7 through the heat absorption side of the first air cooler 3 and the heat absorption side of the second air cooler 10; the outlet of the flash tank 7 The water inlet is connected to the water inlet of the booster pump 6; the air outlet of the flash tank 7 is connected to the air inlet of the steam compressor 8.

In the transcritical carbon dioxide heat pump cycle, an air cooler can be set between the first compressor 1 and the second compressor 2 to make full use of the high temperature heat of the working fluid at the outlet of the first compressor 1, reduce the temperature of the second compressor 2, improve the compressor efficiency, and couple the heat pump and flash circuit with two air coolers to increase the heating capacity and reduce the heat exchange loss; as shown in Figure 4. Specific implementation process: In the transcritical carbon dioxide heat pump cycle, the low temperature and low pressure working fluid is heated by the regenerator and compressed by the first compressor 1 to become a medium pressure and high temperature working fluid. The high temperature working fluid leaving the first compressor 1 enters the air cooler 1 to release heat, the temperature is reduced, and is compressed to high temperature and high pressure by the second compressor 2, and enters the air cooler 2 to release heat and the temperature is reduced. The high pressure working fluid leaving the air cooler 2 releases heat in the regenerator, the temperature is further reduced, and enters the expander to output work, the working fluid temperature and pressure are reduced, and enters the evaporator to absorb heat from the low temperature heat source W1 and return to the starting point of the cycle. In the flash steam supply circuit, the pressurized water leaving the booster pump is divided into two streams, which enter the air cooler 1 and the air cooler 2 respectively to absorb heat and heat up, and the two hot waters are mixed into one hot water. The mixed hot water enters the flash tank and is divided into saturated water and saturated steam. The saturated water is mixed with the supplemented low-temperature water source W3, enters the booster pump to increase the pressure and return to the starting point of the cycle. The saturated steam enters the steam compressor to be compressed, providing steam of different temperatures and pressures. The implementation process of the rest of this embodiment is the same as that of the first embodiment.

Embodiment 5

As shown in Figure 5, this embodiment provides a carbon dioxide transcritical ultra-high temperature heat pump system, including: a transcritical carbon dioxide heat pump circulation unit;

The transcritical carbon dioxide heat pump cycle unit includes a regenerator 9, a compressor unit, an expander 5 and an evaporator 4; the heat release side outlet of the first air cooler 3 passes through the subcooling side of the regenerator 9 Connected to the inlet of the expander 5; one end of the evaporator 4 is connected to the outlet of the expander 5, and the other end is connected to the heat release side inlet of the first air cooler 3 through the compressor unit;

The compressor unit includes a first compressor 1 and a second compressor 2; the outlet of the first compressor 1 is connected to the inlet of the second compressor 2, and the inlet of the first compressor 1 passes through The superheat side of the regenerator 9 is connected to the outlet of the evaporator 4 , and the outlet of the second compressor 2 is connected to the heat release side of the first air cooler 3 . By removing the flash steam supply loop, high-temperature hot water or high-temperature air can be directly supplied, and the air cooler can be used to directly produce hot water and hot air. The heat pump can not only produce steam, but also water and air. The rest of this embodiment is The implementation process is the same as that of Embodiment 1.

Examples 1 to 5 combine the transcritical carbon dioxide heat pump cycle, flash steam recompression, expansion work recovery and high-efficiency heat recovery to propose a carbon dioxide transcritical ultra-high temperature heat pump system, which has the following advantages:

(1) Make full use of the large temperature slip characteristics of heat exchange in the air cooler to increase the heating temperature of the heat pump, enhance the thermal matching performance of the air cooler, and reduce heat exchange losses;

(2) In the flash steam supply circuit, multi-stage flash evaporation is used to reduce throttling flash evaporation losses and supply steam at different temperatures efficiently and flexibly;

(3) Use a steam compressor to recompress the flashed saturated steam, and introduce cold water to offset the superheating effect of compression, so that steam of different temperatures and pressures can be supplied more flexibly;

(4) A regenerator is used in the carbon dioxide heat pump cycle to efficiently utilize the working fluid with a higher temperature after the air cooler releases heat to increase the temperature before compression and improve the performance of the heat pump system;

(5) Use an expander to replace the throttle valve in the carbon dioxide heat pump cycle to recover the energy in the expansion process, reduce throttling losses, and improve the performance of the heat pump system.

The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present application. Replacements shall be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (6)

1. A carbon dioxide transcritical ultra-high temperature heat pump system, comprising:

a transcritical carbon dioxide heat pump cycle unit comprising a first air cooler (3), a regenerator (9), a compressor unit, an expander (5) and an evaporator (4); the heat release side outlet of the first air cooler (3) is connected with the inlet of the expander (5) through the supercooling side of the heat regenerator (9), the inlet of the evaporator (4) is connected with the outlet of the expander (5), the outlet of the evaporator (4) is connected with the inlet of the compressor unit through the overheat side of the heat regenerator (9), and the compressor unit is also connected with the heat release side inlet of the first air cooler (3);

a flash steam supply unit, which is coupled with the transcritical carbon dioxide heat pump cycle unit through the first air cooler (3) in a heat exchange manner; the flash steam supply unit includes: a booster pump (6), a flash tank (7) and a vapor compressor (8); the booster pump (6) is connected with the water inlet of the flash tank (7) through the heat absorption side of the first air cooler (3); the water outlet of the flash tank (7) is connected with the water inlet of the booster pump (6); the air outlet of the flash tank (7) is communicated with the air inlet of the vapor compressor (8).

2. A carbon dioxide transcritical ultra high temperature heat pump system according to claim 1, wherein the compressor unit comprises a first compressor (1) and a second compressor (2);

the outlet of the first compressor (1) is connected with the inlet of the second compressor (2), the inlet of the first compressor (1) is connected with the outlet of the evaporator (4) through the overheat side of the heat regenerator (9), and the outlet of the second compressor (2) is connected with the heat release side of the first air cooler (3).

3. A carbon dioxide transcritical ultra-high temperature heat pump system, comprising: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit which are coupled through heat exchange of the first air cooler (3);

the transcritical carbon dioxide heat pump circulation unit comprises a first air cooler (3), a heat regenerator (9), a compressor unit, an expander (5) and an evaporator (4); the outlet of the heat release side of the first air cooler (3) is connected with the inlet of the evaporator (4) through the supercooling side of the regenerator (9), and the outlet of the evaporator (4) is connected with the inlet of the heat release side of the first air cooler (3) through the compressor unit; the heat release side outlet of the first air cooler (3) is also connected with the inlet of the expander (5), and the outlet of the expander (5) is connected with the heat release side inlet of the first air cooler (3) through the compressor unit;

the flash steam supply unit includes: a booster pump (6), a flash tank (7) and a vapor compressor (8);

the booster pump (6) is connected with the water inlet of the flash tank (7) through the heat absorption side of the first air cooler (3); the water outlet of the flash tank (7) is connected with the water inlet of the booster pump (6); the air outlet of the flash tank (7) is communicated with the air inlet of the vapor compressor (8).

4. A carbon dioxide transcritical ultra high temperature heat pump system according to claim 3, wherein the compressor unit comprises a first compressor (1) and a second compressor (2);

the outlet of the first compressor (1) is connected with the inlet of the second compressor (2), the inlet of the first compressor (1) is connected with the outlet of the evaporator (4) and the outlet of the expander (5) through the overheat side of the heat regenerator (9), and the outlet of the second compressor (2) is connected with the heat release side of the first air cooler (3).

5. A carbon dioxide transcritical ultra-high temperature heat pump system, comprising: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit which are coupled through heat exchange of the first air cooler (3);

the transcritical carbon dioxide heat pump circulation unit comprises a first air cooler (3), a heat regenerator (9), an expander (5), an evaporator (4), a first compressor (1) and a second compressor (2);

the outlet of the heat release side of the first air cooler (3) is connected with the inlet of the expander (5) through the supercooling side of the heat regenerator (9), the outlet of the expander (5) is connected with the inlet of the evaporator (4), the outlet of the evaporator (4) is connected with the inlet of the first compressor (1), the outlet of the first compressor (1) is connected with the inlet of the second compressor (2) through the overheat side of the heat regenerator (9), and the outlet of the second compressor (2) is connected with the heat release side of the first air cooler (3);

the flash steam supply unit includes: a booster pump (6), a flash tank (7) and a vapor compressor (8);

the booster pump (6) is connected with the water inlet of the flash tank (7) through the heat absorption side of the first air cooler (3); the water outlet of the flash tank (7) is connected with the water inlet of the booster pump (6); the air outlet of the flash tank (7) is communicated with the air inlet of the vapor compressor (8).

6. A carbon dioxide transcritical ultra-high temperature heat pump system, comprising: a transcritical carbon dioxide heat pump circulation unit and a flash steam supply unit which are coupled through heat exchange of the air cooler unit;

the transcritical carbon dioxide heat pump circulation unit comprises an air cooler unit, a heat regenerator (9), a first compressor (1), a second compressor (2), an expander (5) and an evaporator (4); the air cooler unit is connected with an inlet of the expander (5) through a supercooling side of the heat regenerator (9); the outlet of the evaporator (4) is connected with the air cooler unit through the overheat side of the heat regenerator (9);

the air cooler unit comprises a first air cooler (3) and a second air cooler (10), and the first air cooler (3) is connected with the second air cooler (10) through the second compressor (2); the second air cooler (10) is connected with the inlet of the expander (5) through the supercooling side of the heat regenerator (9); the first air cooler (3) is connected with the overheat side of the heat regenerator (9) through the first compressor (1);

the flash steam supply unit includes: a booster pump (6), a flash tank (7) and a vapor compressor (8);

the booster pump (6) is connected with the water inlet of the flash tank (7) through the heat absorption side of the first air cooler (3) and the heat absorption side of the second air cooler (10); the water outlet of the flash tank (7) is connected with the water inlet of the booster pump (6); the air outlet of the flash tank (7) is communicated with the air inlet of the vapor compressor (8).