Steam and hot water combined heat pump device

Abstract

The present invention relates to the field of heating technology, and discloses a steam-hot water combined heat pump device, including a carbon dioxide heat pump system and a steam-hot water combined supply system coupled by heat exchange of an air cooler; the carbon dioxide heat pump system includes an expander, the heat release side outlet of the air cooler is connected to the inlet of the expander, and the outlet of the expander is connected to the heat release side inlet of the air cooler; the steam-hot water combined supply system includes a feed water pump, a flash tank and a water vapor compressor, the feed water pump is connected to the inlet of the flash tank through the heat absorption side of the air cooler; the flash tank includes a hot water outlet and a steam outlet connected to the inlet of the water vapor compressor; the expander and the water vapor compressor are connected by a transmission shaft. The device provided by the present invention can fully utilize the phase change latent heat of the carbon dioxide circulating working fluid to provide steam and hot water, and effectively recover the expansion work of supercritical carbon dioxide during throttling through the expander, drive the water vapor compressor to rotate, improve the efficiency of the heat pump, and make the device cleaner and more environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of heating, and in particular to a steam and hot water combined heat pump device. Background Art

[0002] High-temperature steam is the most commonly used heat medium in the industrial, agricultural, commercial, medical, and food industries. At present, high-temperature steam is mainly produced by oil-fired and coal-fired boilers, which not only consumes a lot of energy, but also causes great environmental pollution. With the increasing advancement of ecological civilization construction, traditional oil-fired and coal-fired boilers are bound to be eliminated. Therefore, the development and utilization of clean energy, led by electricity, will win the favor of thermal energy users.

[0003] Carbon dioxide heat pumps use carbon dioxide as a circulating working fluid. By fully utilizing the phase change latent heat of the carbon dioxide circulating working fluid, they can generate a large amount of high-quality heat energy at a relatively low electricity cost. How to further improve the efficiency of carbon dioxide heat pumps is an issue that needs to be studied and solved urgently. Summary of the invention

[0004] An embodiment of the present invention provides a steam-hot water combined heat pump device for improving the efficiency of a carbon dioxide heat pump.

[0005] The embodiment of the present invention provides a steam hot water combined heat pump device, comprising a carbon dioxide heat pump system and a steam hot water combined supply system coupled by heat exchange of an air cooler;

[0006] The carbon dioxide heat pump system includes an expander, the heat release side outlet of the air cooler is connected to the inlet of the expander, and the outlet of the expander is connected to the heat release side inlet of the air cooler; the steam and hot water co-supply system includes a feed water pump, a flash tank and a water vapor compressor, the feed water pump is connected to the inlet of the flash tank through the heat absorption side of the air cooler; the flash tank includes a hot water outlet and a steam outlet connected to the inlet of the water vapor compressor; the expander is connected to the water vapor compressor through a transmission shaft.

[0007] Wherein, the steam and hot water co-supply system further comprises a water supply pump, and the water outlet of the water supply pump is connected to the inlet of the water vapor compressor.

[0008] The carbon dioxide heat pump system further comprises a carbon dioxide compressor and an evaporator. The carbon dioxide compressor, the air cooler, the expander and the evaporator are connected in sequence, and the outlet of the evaporator is connected to the inlet of the carbon dioxide compressor.

[0009] Wherein, the carbon dioxide heat pump system further includes a liquid storage device and a gas-liquid separator;

[0010] The inlet of the liquid storage device is connected to the outlet of the expander, and the liquid storage device includes a gas outlet and a liquid outlet. The gas outlet is connected to the inlet of the carbon dioxide compressor, and the liquid outlet is connected to the inlet of the gas-liquid separator via the evaporator. The outlet of the gas-liquid separator is connected to the inlet of the carbon dioxide compressor.

[0011] The carbon dioxide heat pump system further comprises a regenerator, the heat release side outlet of the air cooler is connected to the inlet of the expander through the subcooling side of the regenerator, and the outlet of the evaporator is connected to the inlet of the carbon dioxide compressor through the superheating side of the regenerator.

[0012] Wherein, the gas path outlet is provided with a pressure reducing valve, and the outlet of the gas-liquid separator is provided with a first one-way valve.

[0013] Wherein, a second one-way valve is provided between the carbon dioxide compressor and the air cooler.

[0014] Wherein, an oil separator is provided between the carbon dioxide compressor and the air cooler.

[0015] The steam-hot water combined heat pump device provided by the embodiment of the present invention uses carbon dioxide as a circulating working fluid, and the carbon dioxide heat pump system can fully utilize the phase change latent heat of the carbon dioxide circulating working fluid to generate a large amount of high-quality thermal energy at a relatively low electricity cost. The carbon dioxide circulating working fluid is in a supercritical state after releasing heat in the air cooler. The supercritical carbon dioxide with a certain pressure and temperature will expand adiabatically in the expander, impacting the impeller of the expander. The potential energy and kinetic energy of the supercritical carbon dioxide are converted into the kinetic energy of the impeller, driving the rotating shaft of the expander to rotate, so that the expander can effectively recover the expansion work of the supercritical carbon dioxide when throttling. The expander and the water vapor compressor are connected by a transmission shaft, and the transmission shaft can transmit the rotation of the expander shaft to the water vapor compressor to drive the water vapor compressor to rotate, thereby improving the efficiency of the carbon dioxide heat pump system, reducing the power consumption of the water vapor compressor, improving the energy utilization effect, and making the device cleaner and more environmentally friendly. When the water vapor compressor is running, negative pressure will be generated in the flash tank. Under negative pressure, the hot water in the flash tank will generate water vapor and enter the water vapor compressor. After being compressed and enthalpy increased by the water vapor compressor, it will become high-temperature steam with a certain pressure. The water vapor compressor can provide a temperature rise of 20℃ to 60℃. The water vapor compressor not only increases the temperature and output of water vapor, but also makes it easier to transport the pressurized water vapor to heat users. The hot water at the bottom of the flash tank can be provided to users who need hot water, so that the device can provide steam or hot water to different users at the same time, which not only makes full and effective use of the low-quality heat in the hot water, but also expands the application scenarios of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic structural diagram of a steam and hot water combined heat pump device provided in an embodiment of the present invention;

[0018] In the figure: 1. air cooler; 2. expander; 3. water feed pump; 4. transmission shaft; 5. carbon dioxide compressor; 6. liquid storage tank; 7. evaporator; 8. gas-liquid separator; 9. pressure reducing valve; 10. first non-return valve; 11. second non-return valve; 12. oil separator; 13. regenerator; 14. flash tank; 15. water vapor compressor; 16. water supply pump. DETAILED DESCRIPTION

[0019] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Furthermore, in the description of the present invention, unless otherwise specified, “plurality”, “multiple roots”, and “multiple groups” mean two or more.

[0023] like Figure 1As shown, an embodiment of the present invention provides a steam-hot water combined heat pump device, including a carbon dioxide heat pump system and a steam-hot water combined supply system. The carbon dioxide heat pump system and the steam-hot water combined supply system are coupled by heat exchange through an air cooler 1; the carbon dioxide heat pump system includes an expander 2, the outlet of the heat release side of the air cooler 1 is connected to the inlet of the expander 2, and the outlet of the expander 2 is connected to the inlet of the heat release side of the air cooler 1; the steam-hot water combined supply system includes a feed water pump 3, a flash tank 14 and a water vapor compressor 15, the feed water pump 3 is connected to the inlet of the flash tank 14 through the heat absorption side of the air cooler 1; the flash tank 14 includes a hot water outlet and a steam outlet connected to the inlet of the water vapor compressor 15; the expander 2 and the water vapor compressor 15 are connected by a transmission shaft 4.

[0024] The steam hot water combined heat pump device provided in the embodiment of the present invention and the carbon dioxide heat pump system use carbon dioxide as the circulating working fluid, which can fully utilize the phase change latent heat of the carbon dioxide circulating working fluid and generate a large amount of high-quality heat energy at a relatively low electricity cost. The air cooler 1 includes a heat release side through which the carbon dioxide circulating working fluid flows and a heat absorption side through which the cooling water flows. Through the heat exchange effect of the air cooler 1, the carbon dioxide circulating working fluid transfers heat to the cooling water in the steam hot water combined supply system when passing through the air cooler 1. After the cooling water is heated on the heat absorption side of the air cooler 1, it enters the flash tank 14.

[0025] The carbon dioxide circulating medium is in a supercritical state after releasing heat in the air cooler 1. The supercritical carbon dioxide with a certain pressure and temperature will expand adiabatically in the expander 2, impacting the impeller of the expander 2. The potential energy and kinetic energy of the supercritical carbon dioxide are converted into the kinetic energy of the impeller, driving the rotating shaft of the expander 2 to rotate, so that the expander 2 can effectively recover the expansion work when the supercritical carbon dioxide is throttled. The expander 2 and the water vapor compressor 15 are connected through the transmission shaft 4. The transmission shaft 4 can transmit the rotation of the rotating shaft of the expander 2 to the water vapor compressor 15 to drive the water vapor compressor 15 to rotate, thereby improving the efficiency of the carbon dioxide heat pump system, reducing the power consumption of the water vapor compressor 15, improving the energy utilization effect, and making the device cleaner and more environmentally friendly.

[0026] The cooling water can absorb heat and rise to about 90°C on the heat absorbing side of the air cooler 1 and enter the flash tank 14; when the water vapor compressor 15 is running, negative pressure will be generated in the flash tank 14. Under the negative pressure environment, the hot water in the flash tank 14 will generate water vapor and enter the water vapor compressor 15; after being compressed and enthalpy increased by the water vapor compressor 15, it will become high-temperature 100-150°C steam with a certain pressure. The water vapor compressor 15 can provide a temperature rise of 20°C to 60°C, and the water vapor compressor 15 can increase the temperature and output of the water vapor. The hot water at the bottom of the flash tank 14 can be provided to users who need hot water, so that the device can provide steam or hot water to different users at the same time, which not only makes full and effective use of the low-quality heat in the hot water, but also expands the application scenarios of the device.

[0027] In a specific embodiment, the steam-hot water co-supply system further includes a water supply pump 16, the outlet of which is connected to the inlet of the water vapor compressor 15. The water supply pump 16 can not only reduce the exhaust temperature of the water vapor compressor 15, reduce the superheat and increase the steam volume by spraying water, but also play a role in lubrication and sealing. When hot water supply is not required, the hot water outlet of the flash tank 14 can also be connected to the water inlet of the water supply pump 16, so that the hot water at the bottom of the flash tank 14 can be used as a water supply source, which can maximize the use of the heat in the water. In addition, the high water supply temperature can reduce the pressure ratio and energy consumption for the water vapor compressor 15.

[0028] In a specific embodiment, the carbon dioxide heat pump system also includes a carbon dioxide compressor 5 and an evaporator 7. The carbon dioxide compressor 5, the air cooler 1, the expander 2 and the evaporator 7 are connected in sequence, and the outlet of the evaporator 7 is connected to the inlet of the carbon dioxide compressor 5. The carbon dioxide circulating medium is in a supercritical state of high temperature and pressure after being compressed by the carbon dioxide compressor 5, and enters the air cooler 1 to release heat to the cooling water. The supercritical carbon dioxide after heat release enters the expander 2 to expand and throttle, output expansion work, and then the liquid carbon dioxide enters the evaporator 7 to absorb heat and evaporate, and finally enters the carbon dioxide compressor 5 again to complete the heat pump cycle. The carbon dioxide compressor 5 can operate at a frequency between 0-50Hz.

[0029] In a specific embodiment, the carbon dioxide heat pump system further includes a liquid reservoir 6 and a gas-liquid separator 8. The inlet of the liquid reservoir 6 is connected to the outlet of the expander 2. The liquid reservoir 6 includes a gas outlet and a liquid outlet. The gas outlet is connected to the inlet of the carbon dioxide compressor 5. The liquid outlet is connected to the inlet of the gas-liquid separator 8 through the evaporator 7. The outlet of the gas-liquid separator 8 is connected to the inlet of the carbon dioxide compressor 5. The carbon dioxide circulating medium is in a gas-liquid two-phase mixed state after expansion and throttling in the expander 2. After entering the liquid reservoir 6 through the inlet of the liquid reservoir 6, the liquid carbon dioxide circulating medium enters the evaporator 7 through the liquid outlet below the liquid reservoir 6 to absorb heat and evaporate and enter the gas-liquid separator 8; the gas outlet of the liquid reservoir 6 and the outlet above the gas-liquid separator 8 are both connected to the inlet of the carbon dioxide compressor 5.

[0030] Furthermore, in order to stabilize the inlet pressure of the carbon dioxide compressor 5, a pressure reducing valve 9 is provided at the gas outlet of the liquid storage tank 6; a first one-way valve 10 is provided at the outlet of the gas-liquid separator 8, and a second one-way valve 11 can be provided between the carbon dioxide compressor 5 and the air cooler 1 to prevent gas back-blocking. In addition, in order to ensure the safe and efficient operation of the equipment, an oil separator 12 can also be provided between the carbon dioxide compressor 5 and the air cooler 1 to separate the lubricating oil discharged from the carbon dioxide compressor 5 along with the carbon dioxide circulating working medium.

[0031] In a specific embodiment, the carbon dioxide heat pump system further includes a regenerator 13, which includes a subcooling side and a superheating side. The heat release side outlet of the air cooler 1 is connected to the inlet of the expander 2 through the subcooling side of the regenerator 13, and the outlet of the evaporator 7 is connected to the inlet of the carbon dioxide compressor 5 through the superheating side of the regenerator 13. The regenerator 13 is provided to subcool the carbon dioxide circulating medium at the outlet of the air cooler 1 on the one hand, and to superheat the carbon dioxide compressor 5 on the other hand, thereby improving the COP (coefficient of performance) of the carbon dioxide heat pump system and reducing energy loss.

[0032] It can be seen from the above embodiments that the steam hot water combined heat pump device provided by the present invention and the carbon dioxide heat pump system use carbon dioxide as the circulating working fluid, which can make full use of the phase change latent heat of the carbon dioxide circulating working fluid and generate a large amount of high-quality heat energy at a relatively low electricity cost. After releasing heat in the air cooler 1, the carbon dioxide circulating working fluid is in a supercritical state, and the supercritical carbon dioxide with a certain pressure and temperature will adiabatically expand in the expander 2, impacting the impeller of the expander 2, and the potential energy and kinetic energy of the supercritical carbon dioxide are converted into the kinetic energy of the impeller, driving the rotating shaft of the expander 2 to rotate, so that the expander 2 can effectively recover the expansion work of the supercritical carbon dioxide during throttling. The expander 2 and the water vapor compressor 15 are connected through the transmission shaft 4, and the transmission shaft 4 can transmit the rotation of the expansion machine 2 shaft to the water vapor compressor 15 to drive the water vapor compressor 15 to rotate, thereby improving the efficiency of the carbon dioxide heat pump system, reducing the power consumption of the water vapor compressor 15, improving the energy utilization effect, and making the device cleaner and more environmentally friendly. When the water vapor compressor 15 is in operation, negative pressure will be generated in the flash tank 14. Under the negative pressure environment, the hot water in the flash tank 14 will generate water vapor and enter the water vapor compressor 15; after being compressed and enthalpy increased by the water vapor compressor 15, it will become high-temperature steam with a certain pressure. The water vapor compressor 15 can provide a temperature rise of 20°C to 60°C. The water vapor compressor 15 not only increases the temperature and output of the water vapor, but also makes it easier to transport the pressurized water vapor to heat users. The hot water at the bottom of the flash tank 14 can be provided to users who need hot water, so that the device can provide steam or hot water to different users at the same time, which not only makes full and effective use of the low-quality heat in the hot water, but also expands the application scenarios of the device.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A steam hot water combined heat pump device, characterized in that: It includes a carbon dioxide heat pump system and a steam hot water cogeneration system coupled by heat exchange with an air cooler; The carbon dioxide heat pump system includes an expander, the heat release side outlet of the air cooler is connected to the inlet of the expander, and the outlet of the expander is connected to the heat release side inlet of the air cooler; the steam and hot water co-supply system includes a feed water pump, a flash tank and a water vapor compressor, the feed water pump is connected to the inlet of the flash tank through the heat absorption side of the air cooler; the flash tank includes a hot water outlet and a steam outlet connected to the inlet of the water vapor compressor; the expander is connected to the water vapor compressor through a transmission shaft; The carbon dioxide heat pump system also includes a liquid storage device and a gas-liquid separator; The inlet of the liquid storage device is connected to the outlet of the expander, the liquid storage device includes a gas outlet and a liquid outlet, the gas outlet is connected to the inlet of the carbon dioxide compressor, the liquid outlet is connected to the inlet of the gas-liquid separator via the evaporator, and the outlet of the gas-liquid separator is connected to the inlet of the carbon dioxide compressor; The carbon dioxide heat pump system also includes a regenerator, the heat release side outlet of the air cooler is connected to the inlet of the expander through the subcooling side of the regenerator, the outlet of the evaporator is connected to the inlet of the carbon dioxide compressor through the superheating side of the regenerator, and the gas path outlet of the liquid storage device is connected to the inlet of the carbon dioxide compressor through the superheating side of the regenerator; the gas-liquid separator is arranged between the evaporator and the superheating side of the regenerator.

2. The steam hot water combined heat pump device according to claim 1, characterized in that: The steam and hot water co-supply system further comprises a water supply pump, the water outlet of which is connected to the inlet of the water vapor compressor.

3. The steam hot water combined heat pump device according to claim 1, characterized in that: The carbon dioxide heat pump system further comprises a carbon dioxide compressor and an evaporator. The carbon dioxide compressor, the air cooler, the expander and the evaporator are connected in sequence, and the outlet of the evaporator is connected to the inlet of the carbon dioxide compressor.

4. The steam hot water combined heat pump device according to claim 1, characterized in that: The outlet of the gas path is provided with a pressure reducing valve, and the outlet of the gas-liquid separator is provided with a first one-way valve.

5. The steam hot water combined heat pump device according to claim 3, characterized in that: A second one-way valve is provided between the carbon dioxide compressor and the air cooler.

6. The steam hot water combined heat pump device according to claim 3, characterized in that: An oil separator is provided between the carbon dioxide compressor and the air cooler.

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