Oil-free centrifugal cooling and heating simultaneous high-temperature heat pump unit, system and cooling and heating simultaneous method

Abstract

The invention relates to the field of heat pumps, in particular to an oil-free centrifugal cooling and heating simultaneous high-temperature heat pump unit, an oil-free centrifugal cooling and heating simultaneous high-temperature heat pump system and a high-temperature heat pump cooling and heating simultaneous method. The oil-free centrifugal high-temperature heat pump unit capable of simultaneously heating and cooling comprises an evaporator; the low-pressure stage oil-free centrifugal compressor is communicated with the evaporator through an air suction pipeline; the high-pressure stage oil-free centrifugal compressor is communicated with the low-pressure stage oil-free centrifugal compressor through a compressor connecting pipeline; the economizer is communicated with the compressor connecting pipeline through an air supply pipeline; the economizer is communicated with the evaporator through a low-pressure throttling pipeline; the condenser is communicated with the economizer through a high-pressure throttling pipeline; the condenser is communicated with the evaporator through a liquid bypass pipeline; the condenser is provided with a hot water pipeline, and the outlet end of the hot water pipeline is provided with a hot water outlet valve.

Description

Technical Field

[0001] The invention relates to the field of heat pumps, in particular to an oil-free centrifugal high-temperature heat pump unit with simultaneous cooling and heating, an oil-free centrifugal high-temperature heat pump system with simultaneous cooling and heating, and a high-temperature heat pump simultaneous cooling and heating method. Background Art

[0002] Heat pump is a highly efficient and energy-saving device that makes full use of low-grade thermal energy. Heat can be transferred spontaneously from a high-temperature object to a low-temperature object, but not spontaneously in the opposite direction. The working principle of a heat pump is a mechanical device that forces heat to flow from a low-temperature object to a high-temperature object in a reverse cycle. It consumes only a small amount of reverse cycle net work to obtain a large amount of heat supply, and can effectively utilize the difficult-to-use low-grade thermal energy to achieve energy conservation. Heat pumps are also a new energy technology that has attracted much attention around the world. It is different from the familiar mechanical equipment that can increase potential energy - "pumps"; heat pumps usually obtain low-grade thermal energy from natural air, water or soil, do work with electricity, and then provide people with usable high-grade thermal energy.

[0003] Heat pumps are devices that transfer heat energy from low temperature to high temperature, with significant energy-saving effects. In the context of energy shortage, the application of heat pump technology is becoming more and more widespread. Currently, common heat pumps mainly include three solutions:

[0004] First, dual compressors are used for compression in series, that is, the economizer air is mixed and then enters the compressor. After being compressed by the compressor, the refrigerant goes through several processes such as heat release in the condenser, throttling by the electronic expansion valve, air replenishment in the economizer, and heat absorption in the evaporator, and is finally sucked into the compressor to complete the entire heating cycle and improve the energy efficiency of the unit. However, the dual compressor series compression method requires users to provide a low-grade heat source above 30°C. If the compressor is a centrifugal compressor, the temperature of the low-grade heat source needs to reach above 50°C. Few users can provide such a high-grade and continuously stable waste heat source; and this scheme has a low compression ratio and a small application range of high-temperature heat pumps.

[0005] Second, the fluorine circuit cascade method is adopted, and the high-pressure stage unit and the low-pressure stage unit are connected by an intermediate heat exchanger, and the fluorine circuit cascade or water circuit series method is adopted. However, the whole system and control are complicated, the cost and failure rate are high, and the unit is difficult to operate simply and efficiently.

[0006] Third, the water series connection method is to use two units, connect the water outlet of the low-pressure condenser to the water inlet of the high-pressure evaporator; one unit is heated for the first time, and the other unit is heated for the second time.

[0007] The above three existing heat pump solutions, as well as other existing heat pump unit solutions, can increase the temperature of hot water production, but still have at least the following problems:

[0008] 1. In the existing refrigeration and heating units, the evaporator of the traditional air conditioner can take in 12℃ water and output 7℃ water, which can produce 7℃ low-temperature water. However, the traditional air conditioner can only produce low-temperature water, not high temperature, and cannot produce hot water! Therefore, when high-temperature water is needed, a heat pump is needed. However, the use of a heat pump must have a waste heat source to transfer the low-temperature heat to the high-temperature heat pump to turn the low temperature into high temperature. However, the current refrigeration side evaporator cannot achieve such a low temperature. It must be 30℃, 50℃, 60℃... etc., and a certain high-temperature waste heat source is required. Only on the basis of the waste heat source can further produce high temperature. Therefore, there are two major problems. On the one hand, it is impossible to produce 7℃ low-temperature water. On the other hand, its high temperature is not high, all of which are within 50-80 degrees. It is impossible to produce high-temperature hot water and steam above 100℃;

[0009] 2. Existing heat pump units are limited by the compression ratio. Conventional high-temperature heat pumps require a higher evaporation temperature when producing high-temperature hot water or steam. Therefore, although heating is achieved, cooling cannot be performed at the same time, that is, it is impossible to produce both hot and cold at the same time;

[0010] 3. Conventional high-temperature heat pump products are mostly single products for producing hot water or steam. They cannot have the functions of producing hot water and steam at the same time, and cannot switch between hot water and steam according to usage requirements;

[0011] 4. The compressors used in conventional high-temperature heat pumps include scroll, piston, screw, and centrifugal compressors, all of which are oil-carrying compressors. They have scrolls, pistons, and screws, and all require lubricating oil for lubrication. The lubricating oil will occupy the compression volume of the compressor, and there will be friction resistance, resulting in low compressor efficiency;

[0012] 5. Conventional high-temperature heat pump units need to add lubricating oil pipelines and be equipped with oil separators, oil coolers and other components, which increases the complexity of the unit piping and also increases the unit cost;

[0013] 6. Since conventional high-temperature heat pumps use compressors that require lubricating oil, they cannot run at high speeds, the compressors are larger in size, and lubricating oil pipelines are required, all of which lead to the larger size of conventional high-temperature heat pumps;

[0014] 7. In industrial manufacturing, hot water / steam and cold water / air are needed in many aspects. In view of these situations, traditional factories currently need a chiller to provide air conditioning for constant temperature and humidity in the workshop, and a boiler to provide hot water or steam, which causes great waste;

[0015] 8. Although the heating capacity of heat pump units has been improved, they can only produce hot water below 100°C, and still cannot achieve heating above 100°C, and cannot provide cooling for users while heating; in some process heat use scenarios, there will be a demand for heating above 100°C, and there will also be a demand for low-temperature cooling; however, due to the compression ratio and operating efficiency of the compressor, there is no heat pump unit on the market that can produce hot water or steam above 100°C, nor can it provide cold water while achieving hot water or steam above 100°C;

[0016] 9. In general, the refrigeration and cooling of heat pump units are contradictory issues. Only one of the two can be realized, and they are not compatible at the same time. If cooling is guaranteed, heating cannot be achieved; and if heating is guaranteed, cooling cannot be achieved.

[0017] 10. The current heat pump unit can only shut down when the compressor load needs to be reduced and the reduction exceeds the minimum speed of the compressor. There is no other effective way to deal with it;

[0018] 11. In high-temperature heat pumps, the compression ratio of the compressor determines how high the temperature can be raised. In order to increase the compression ratio of the compressor, centrifugal multi-stage compressors are currently used. Multi-stage compression improves the compression capacity, but the disadvantages are also very large. On the one hand, the price cost is very high, and on the other hand, the speed of traditional compressors cannot be too high. After the speed is high, the wear is particularly large;

[0019] 12. In addition, for multi-stage compressors, the speed of each stage must be the same at the same time. It cannot have different speeds for each stage. If each stage has different speeds, its control will be very troublesome and complicated, and the cost is high.

[0020] 13. The current heat pump units will waste energy when hot water is no longer in use; and when steam is no longer in use, the unit must be stopped or the steam must be discharged through a safety valve, otherwise the steam pressure will be too high and dangerous, resulting in great waste. And when water needs to be replenished inside the unit, the replenished water is not mixed evenly. Summary of the invention

[0021] The purpose of the present invention is to at least solve the problem that the current heat pump cannot control both cooling and heating, and to bring about corresponding technical effects.

[0022] In order to solve the above technical problems, the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention comprises:

[0023] Evaporator;

[0024] A low-pressure oil-free centrifugal compressor, which is connected to the evaporator through a suction line;

[0025] A high-pressure oil-free centrifugal compressor, which is connected to the low-pressure oil-free centrifugal compressor through a compressor connecting pipeline;

[0026] An economizer, the economizer is connected to the compressor connecting pipeline through an air supply pipeline; and the economizer is connected to the evaporator through a low-pressure throttling pipeline;

[0027] A condenser, which is connected to the high-pressure oil-free centrifugal compressor through an exhaust pipeline; and the condenser is connected to the economizer through a high-pressure throttling pipeline; and the condenser is connected to the evaporator through a liquid bypass pipeline; the condenser is equipped with a hot water pipeline, the water inlet end of the hot water pipeline is equipped with a hot water inlet valve, the outlet end of the hot water pipeline is equipped with a hot water outlet valve, and the hot water pipeline is connected to a steam pipeline;

[0028] A flash tank having a steam outlet valve, the flash tank is connected to the steam pipe, and the steam pipe is equipped with a steam return valve; the flash tank has a return water pipe, the return water pipe is connected to the hot water pipe, and the hot water pipe is equipped with a hot water return valve.

[0029] As a preferred embodiment of the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention, the high-pressure throttling pipeline between the condenser and the economizer is installed with a high-pressure throttling device; the low-pressure throttling pipeline is installed with a low-pressure throttling device.

[0030] As a preferred embodiment of the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention, the high-pressure throttling pipeline is connected to a motor cooling pipeline; the motor cooling pipeline is connected to the low-pressure oil-free centrifugal compressor and the high-pressure oil-free centrifugal compressor;

[0031] The motor cooling pipeline is provided with a high-pressure motor cooling throttling device at a position adjacent to the high-pressure oil-free centrifugal compressor; the motor cooling pipeline is provided with a low-pressure motor cooling throttling device at a position adjacent to the low-pressure oil-free centrifugal compressor.

[0032] As a preferred implementation scheme of the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention, the air supply pipeline is installed with an intermediate air supply valve.

[0033] As a preferred embodiment of the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention, it includes a liquid bypass pipeline, which is provided with a liquid supply bypass valve; one end of the liquid bypass pipeline is connected to the condenser, and the other end of the liquid bypass pipeline is connected to the evaporator.

[0034] As a preferred embodiment of the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention, it includes a hot gas bypass pipeline, which is equipped with a hot gas bypass valve; one end of the hot gas bypass pipeline is connected to the exhaust pipeline, and the other end of the hot gas bypass pipeline is connected to the intake pipeline.

[0035] As a preferred implementation scheme of the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating of the present invention, it comprises a user plate heat exchanger; the user plate heat exchanger is connected to the hot water pipeline.

[0036] As a preferred embodiment of the oil-free centrifugal high-temperature heat pump unit of the present invention, it includes a water supply pipe, and the hot water pipe is connected to the hot water pipe and the flash tank at the same time; a first water supply valve is installed between the water supply pipe and the hot water pipe; and a second water supply valve is installed between the water supply pipe and the flash tank.

[0037] The oil-free centrifugal high-temperature heat pump system for simultaneous cooling and heating of the present invention comprises:

[0038] The evaporator obtains the first low-temperature water, and makes the refrigerant exchange heat with the first low-temperature water; absorbs the heat of the water temperature by evaporation, and makes the temperature of the first low-temperature water drop from the first low temperature to the second low temperature;

[0039] A low-pressure oil-free centrifugal compressor obtains the low-temperature and low-pressure refrigerant from the evaporator and compresses it into a high-pressure and high-temperature refrigerant;

[0040] A high-pressure oil-free centrifugal compressor; receiving the high-pressure and high-temperature refrigerant from the low-pressure oil-free centrifugal compressor and further compressing it into a higher-pressure and high-temperature gaseous refrigerant, wherein the high-pressure oil-free centrifugal compressor and the low-pressure oil-free centrifugal compressor have different speeds and stages;

[0041] The condenser obtains the second low-temperature water and receives the high-temperature and high-pressure refrigerant from the high-pressure oil-free centrifugal compressor; the high-temperature and high-pressure refrigerant is circulated with the second low-temperature water for heat exchange, heat is released, and the second low-temperature water is gradually heated to high-temperature water, so that the second low-temperature water is raised from the first temperature to the second temperature and output; wherein the high-pressure refrigerant is firstly reduced in pressure by the high-pressure throttling device and is delivered to the economizer; the economizer receives the refrigerant from the high-pressure oil-free centrifugal compressor and is output in two parts, one part of the refrigerant is mixed with the refrigerant compressed by the low-pressure oil-free centrifugal compressor and then enters the high-pressure oil-free centrifugal compressor, and the other part of the refrigerant is reduced in pressure by the low-pressure throttling device for the second time and then enters the evaporator, completing the refrigeration and heating cycle.

[0042] The high-temperature heat pump cooling and heating method of the present invention adopts any of the above-mentioned oil-free centrifugal cooling and heating high-temperature heat pump units.

[0043] Obtain first low-temperature water, and perform heat exchange between the first low-temperature water and the evaporator; and reduce the first low-temperature water from a first low temperature to a second low temperature;

[0044] Using a low-pressure oil-free centrifugal compressor to perform a first compression on the low-temperature and low-pressure refrigerant from the evaporator and compress it into a high-pressure and high-temperature refrigerant;

[0045] The high-pressure and high-temperature refrigerant that has been compressed for the first time is compressed for the second time by using a high-pressure oil-free centrifugal compressor with different speeds and stages, so as to raise the refrigerant to a higher temperature;

[0046] Obtain second low-temperature water, perform heat exchange on the second low-temperature water using a higher-temperature refrigerant in a condenser, heat the second low-temperature water from the first temperature to the second temperature, and output the second low-temperature water as high-temperature water; wherein the high-pressure refrigerant is reduced in pressure twice and delivered to the evaporator; and complete the refrigeration and heating cycle.

[0047] As a preferred embodiment of the high-temperature heat pump method for producing heat and cold simultaneously, steam of high-temperature water having a second temperature is obtained, and the steam is supplied to a flash tank, so that the steam is separated from water vapor in the flash tank;

[0048] The water in the flash tank is first replenished to the condenser under the action of gravity;

[0049] When the pressure in the flash tank and the condenser is unbalanced, the steam pressure in the flash tank is used to replenish the water in the flash tank into the condenser for a second time to achieve water replenishment.

[0050] As a preferred embodiment of the high-temperature heat pump hot and cold simultaneous production method of the present invention, water is added to the flash tank, and the added cold water is used to cool the flash tank and prevent the steam pressure in the flash tank from being too high; and the steam in the flash tank is used to preheat the water;

[0051] Add the preheated water into the condenser to make the added water mixed more evenly.

[0052] As a preferred implementation of the high-temperature heat pump cooling and heating method of the present invention, the low-pressure oil-free centrifugal compressor and the high-pressure oil-free centrifugal compressor respectively use different rotation speeds.

[0053] Beneficial Effects

[0054] The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating, the oil-free centrifugal high-temperature heat pump system for simultaneous cooling and heating, and the high-temperature heat pump simultaneous cooling and heating method of the present invention solve the above existing problems and other existing problems not mentioned above one by one, and correspondingly bring at least the following innovative advantages:

[0055] 1. It solves the current problem that users must provide a continuous and stable low-grade heat source;

[0056] 2. Solved the problems of fluorine circuit cascade or water circuit series system and control complexity, high cost and failure rate;

[0057] 3. The present invention can produce both hot and cold water, which eliminates the need for users to provide low-grade heat sources above 30°C. It can also provide users with hot water or steam above 100°C while meeting their cooling needs. It can provide users with cold water / cold air while providing hot water / steam, thus achieving both hot and cold water production, greatly increasing the scope of application. It solves the problem that currently low-temperature water of 7°C and high-temperature hot water / steam above 100°C cannot be produced simultaneously.

[0058] 4. It solves the problem that the current system cannot produce both hot water and steam at the same time, and cannot switch between hot water and steam according to usage requirements;

[0059] 5. It solves the problem that the current compressors all need lubricating oil for lubrication, the lubricating oil will occupy the compression volume of the compressor, and there will be friction resistance, and the compressor efficiency is low;

[0060] 6. It solves the problem that the conventional high-temperature heat pump units need to add lubricating oil pipelines and be equipped with oil separators, oil coolers and other components, which causes the unit piping to be complicated and costly;

[0061] 7. Since the low-pressure oil-free centrifugal compressor and the high-pressure oil-free centrifugal compressor of the present invention are oil-free centrifugal compressors, the operation efficiency is higher, and the lubricating oil pipeline and components are omitted, and the volume of the unit is smaller;

[0062] 8. The hot and cold system of the present invention solves the problem that current industrial production requires hot water / steam and cold water / air at the same time, which causes great waste;

[0063] 9. The present invention solves the contradiction that the current heat pump unit can only choose between cooling and refrigeration, breaks the traditional concept of the industry, and provides a new idea for the development of new technologies;

[0064] 10. The present invention solves the problem that the existing heat pump unit can only shut down when the compressor load needs to be reduced and the reduction exceeds the minimum speed of the compressor by setting the hot gas bypass pipeline and the hot gas bypass valve.

[0065] 11. The present invention greatly improves the compression capacity by combining the low-pressure oil-free centrifugal compressor and the high-pressure oil-free centrifugal compressor, solving the problems of high cost, large wear and complex control of the current multi-stage compression;

[0066] 12 The present invention realizes automatic siphon water replenishment through the siphon circulation of the flash tank and the condenser, and realizes the use of the steam pressure in the flash tank to promote water replenishment, providing a new solution for steam water replenishment;

[0067] 13. The present invention directly replenishes water into the flash tank, which directly brings about the completion of water replenishment. Another effect brought about by the cold water added can, on the one hand, play a role in cooling down and preventing the steam pressure in the flash tank from being too high, and on the other hand, avoids wasting energy by discharging the steam; and the water added into the flash tank can also be preheated in the flash tank, and after preheating, it is already at high temperature when it is added into the condenser through the return pipe, and the added water is mixed more evenly; and it also solves the current dilemma that when the user does not need hot water / steam but needs cold water / cooling, the whole machine cannot be shut down, and shutting down will affect the use of refrigeration, while not shutting down will affect the waste of steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a connection relationship diagram of the present invention.

[0069] In the figure: 1. Suction pipeline; 2. Compressor connecting pipeline; 3. Exhaust pipeline; 4. High-pressure throttling pipeline; 5. Air supply pipeline; 6. Low-pressure throttling pipeline; 7. Liquid bypass pipeline; 8. Hot gas bypass pipeline; 9. Motor cooling pipeline; 11. Low-pressure oil-free centrifugal compressor; 12. High-pressure oil-free centrifugal compressor; 13. Condenser; 14. High-pressure throttling device; 15. Economizer; 16. Low-pressure throttling device; 17. Evaporator; 18. Flash tank; 19 1. The first water supply valve; 20. The second water supply valve; 21. The hot gas bypass valve; 22. The high-pressure motor cooling throttling device; 23. The low-pressure motor cooling throttling device; 24. The intermediate air supply valve; 25. The liquid supply bypass valve; 26. The hot water outlet valve; 27. The hot water inlet valve; 28. The steam outlet valve; 29. ​​The steam return valve; 30. The hot water return valve; 31. The user board exchanger; 32. The steam pipe; 33. The return pipe; 34. The hot water pipe; 35. The water supply pipe. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the technical solution of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of specific embodiments of the present disclosure.

[0071] The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only part of the embodiments of the present disclosure, but not all of the embodiments.

[0072] Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.

[0073] Example 1

[0074] The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating, the oil-free centrifugal high-temperature heat pump system for simultaneous cooling and heating, and the high-temperature heat pump simultaneous cooling and heating method of the present invention have the following operating procedures: the low-pressure gaseous refrigerant is compressed by the low-pressure oil-free centrifugal compressor 11, and then enters the high-pressure oil-free centrifugal compressor 12 through the compressor connecting pipeline 2 for further compression. After the two-stage compression, the temperature and pressure of the gaseous refrigerant are greatly increased, and the gaseous refrigerant enters the condenser 13 through the exhaust pipeline 3. In the condenser 13, the high-pressure gaseous refrigerant releases heat to the outside and condenses into a high-pressure liquid refrigerant. In this link, water can be heated to above 100°C to provide external heat or steam, wherein the high-pressure liquid After the pressure of the refrigerant is reduced by the high-pressure throttling device 14 in the high-pressure throttling pipeline 4, it enters the economizer 15. The refrigerant in the economizer 15 is divided into two parts. One part of the medium-pressure gaseous refrigerant passes through the air supply pipeline 5 and is mixed with the refrigerant in the compressor connecting pipeline 2 and then enters the high-pressure oil-free centrifugal compressor 12. The other part of the medium-pressure liquid refrigerant passes through the low-pressure throttling device 16 in the low-pressure throttling pipeline 6 and enters the evaporator 17. The low-pressure liquid refrigerant in the evaporator 17 absorbs heat and becomes a low-pressure gaseous refrigerant, which is then sucked into the low-pressure oil-free centrifugal compressor 11 through the suction pipeline 1 for compression, thus completing a refrigeration and heating cycle.

[0075] For further information, see Figure 1 ,include:

[0076] Evaporator 17;

[0077] A low-pressure oil-free centrifugal compressor 11, which is connected to the evaporator 17 via a suction line 1;

[0078] A high-pressure oil-free centrifugal compressor 12, which is connected to the low-pressure oil-free centrifugal compressor 11 through a compressor connecting pipeline 2;

[0079] An economizer 15, the economizer 15 is connected to the compressor connecting pipeline 2 through the air supply pipeline 5; and the economizer 15 is connected to the evaporator 17 through the low-pressure throttling pipeline 6;

[0080] A condenser 13, which is connected to the high-pressure oil-free centrifugal compressor 12 through an exhaust pipe 3; and the condenser 13 is connected to the economizer 15 through a high-pressure throttling pipe 4; and the condenser 13 is connected to the evaporator 17 through a liquid bypass pipe 7; the condenser 13 is installed with a hot water pipe 34, the water inlet end of the hot water pipe 34 is installed with a hot water inlet valve 27, the outlet end of the hot water pipe 34 is installed with a hot water outlet valve 26, and the hot water pipe 34 is connected with a steam pipe 32;

[0081] The flash tank 18 has a steam outlet valve 28 , and the flash tank 18 is connected to the steam pipe 32 , and the steam pipe 32 is equipped with a steam return valve 29 ; the flash tank 18 has a return water pipe 33 , and the return water pipe 33 is connected to the hot water pipe 34 , and the hot water pipe 34 is equipped with a hot water return valve 30 .

[0082] Among them, the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 are oil-free centrifugal compressors, and specifically can be air-suspended centrifugal compressors or magnetically suspended centrifugal compressors; the impeller can be a single-stage impeller or a multi-stage impeller, wherein the multi-stage impeller refers to an impeller with two or more stages. In this embodiment, at least the high-pressure oil-free centrifugal compressor 12 is preferably a two-stage impeller air-suspended centrifugal compressor, and different compression ratios can be selected according to user needs. In this design example, a large compression ratio compressor is selected, which can provide users with high-temperature hot water or steam above 120°C while providing users with 7°C cold water; 7°C cold water / 120°C hot water is only the maximum temperature rise condition of this unit, and the unit can operate within the range of the temperature difference less than or equal to 113°C. The specific target temperature is determined according to the actual working conditions and is not limited to this temperature, the same below.

[0083] See also Figure 1 The flash tank 18 is located higher than the condenser, and needs to maintain a certain liquid level height, and use the gravity difference and density difference to circulate water vapor to produce high-temperature steam. Therefore, the flow circulation type of the fluid in the flash tank 18 can be a siphon circulation type; of course, a water pump can also be added to achieve a water pump circulation type.

[0084] The condenser 13 can be a water-cooled condenser or an air-cooled condenser; when the user uses the water-cooled condenser, the high-temperature heat pump unit provides the user with high-temperature hot water or high-temperature steam; when the user uses the air-cooled condenser, the high-temperature heat pump provides the user with high-temperature hot air.

[0085] The economizer 15 can be a flash economizer or a subcooling economizer. The number of economizers 15 can be configured as one or more, and the maximum number of economizers is the total number of the first and second stage impellers minus one; in this embodiment, the present invention preferably uses a flash economizer. The function of the economizer 15 is to improve energy efficiency. It can replenish gas in the middle. There is gas above the economizer 15 and liquid below. The liquid is transmitted to the evaporator 17; the gaseous refrigerant in the economizer 15 enters the high-pressure oil-free centrifugal compressor 12 to prevent gas from entering the evaporator 17. At present, the conventional economizer 15 is to be placed behind the evaporator 17 and in front of the compressor to prevent the compressor from sucking gas with liquid; and the economizer 15 of the present invention is placed behind the low-pressure oil-free centrifugal compressor 11 and in front of the high-pressure oil-free centrifugal compressor 12, so that the replenished gaseous refrigerant can be mixed with the refrigerant compressed by the low-pressure oil-free centrifugal compressor 11 and enter the high-pressure oil-free centrifugal compressor 12.

[0086] The evaporator 17 can be a water-cooled evaporator or an air-cooled evaporator. When the user uses the water-cooled evaporator, the present invention provides the user with low-temperature cold water; when the user uses the air-cooled evaporator, the present invention provides the user with low-temperature cold air.

[0087] For further information, see Figure 1 The high-pressure throttling pipeline 4 between the condenser 13 and the economizer 15 is installed with a high-pressure throttling device 14; the low-pressure throttling pipeline 6 is installed with a low-pressure throttling device 16; the high-pressure throttling device 14 and the low-pressure throttling device 16 are used to adjust the flow rate of the refrigerant.

[0088] For further information, see Figure 1 The high-pressure throttling pipeline 4 is connected to a motor cooling pipeline 9; the motor cooling pipeline 9 is connected to the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12;

[0089] The motor cooling pipeline 9 is provided with a high-pressure motor cooling throttling device 22 at a position adjacent to the high-pressure oil-free centrifugal compressor 12; the motor cooling pipeline 9 is provided with a low-pressure motor cooling throttling device 23 at a position adjacent to the low-pressure oil-free centrifugal compressor 11. Through the above arrangement, it can be used for cooling the motors of the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12.

[0090] For further information, see Figure 1 The air supply pipeline 5 is equipped with an intermediate air supply valve 24 for adjusting the intermediate air supply pressure and air supply flow.

[0091] For further information, see Figure 1, including a liquid bypass pipeline 7, which is provided with a liquid supply bypass valve 25; one end of the liquid bypass pipeline 7 is connected to the condenser 13, and the other end of the liquid bypass pipeline 7 is connected to the evaporator 17. Through the arrangement of the liquid bypass pipeline 7, when the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 start to operate during the initial startup of the present invention, the pressure difference is not enough, and the position of the economizer 15 is slightly higher, and there is not enough pressure to pump the refrigerant of the condenser 13 to the economizer 15, and the liquid of the economizer 15 may be directly taken away by the high-pressure oil-free centrifugal compressor 12 when the machine is just started. Therefore, the liquid bypass pipeline 7 can directly pump some refrigerant into the evaporator 17 when the machine is just started, so that the refrigerant flows more smoothly, so that the problem of low suction pressure and the refrigerant in the evaporator 17 being completely absorbed will not occur during the startup process. As the pressure gradually recovers after startup, the liquid supply bypass valve 25 gradually reduces the flow rate, allowing more refrigerant to enter the economizer 15, until the pressure difference reaches the predetermined target and the bypass valve is completely closed automatically. Therefore, the condenser 13 is connected to the bottom of the evaporator 17 through the liquid bypass pipeline 7, and the liquid bypass pipeline 7 is set to solve the problem of insufficient liquid supply and low suction pressure during startup or low pressure difference conditions.

[0092] For further information, see Figure 1 , including a hot gas bypass pipeline 8, which is equipped with a hot gas bypass valve 21; one end of the hot gas bypass pipeline 8 is connected to the exhaust pipeline 3, and the other end of the hot gas bypass pipeline 8 is connected to the suction pipeline 1. The condenser 13 is connected to the upper part of the evaporator 17 through the hot gas bypass pipeline 8, and a hot gas bypass valve 21 is provided to adjust the compressor surge and unit load; specifically: the hot gas bypass pipeline 21 is used to solve the problem of centrifugal compressor surge; on the other hand, it can be used to solve the situation when the load is less than the minimum load of the compressor; because the speed of the compressor cannot be infinitely small, the compressor has a minimum speed, so through the setting of the hot gas bypass pipeline 8 and the hot gas bypass valve 21, when the load drops below the minimum load of the compressor, the overall load can be reduced through the hot gas bypass valve 21. At this time, the hot gas bypass valve 21 is opened. At this time, the compressor is maintained at the lowest speed of surge. The compressor has been working, but there is no cooling or heating. A part of the refrigerant is diverted to circulate between the hot gas bypass pipeline 8 and the low-pressure stage oil-free centrifugal compressor 11 and the high-pressure stage oil-free centrifugal compressor 12, and another small part continues to enter the condenser 13. Therefore, since a part of it is not working, the heat release and heat absorption are greatly reduced, so that the load of the unit is lower and the working requirements are met.

[0093] For further information, see Figure 1 , including a user plate changer 31; the user plate changer 31 is connected to the hot water pipe 34.

[0094] When in use, the hot water or steam is controlled by the opening and closing states of the hot water inlet valve 26, the hot water outlet valve 27, the steam return valve 29 and the hot water return valve 30. When the hot water outlet valve 26 and the hot water inlet valve 27 are closed, and the steam outlet valve 28, the steam return valve 29 and the hot water return valve 30 are opened, the present invention produces high-temperature steam; when the hot water outlet valve 26 and the hot water inlet valve 27 are opened, and the steam outlet valve 28, the steam return valve 29 and the hot water return valve 30 are closed, the unit produces high-temperature hot water. Thus, the present invention can switch between hot water and steam, or produce hot water and steam at the same time. The process of producing hot water is: the water in the user's plate exchanger 31 exchanges heat with the condenser, circulates first, and gradually raises the temperature until the water temperature is raised to 120°C. In addition, the user can use heat or directly use hot water. As long as the user's heat consumption is less than the heat generation of the unit, the temperature of the hot water can be maintained to continue to rise and stabilize at 120°C; and water can be replenished. The process of producing steam is as follows: the water in the condenser 13 for heat exchange is heated to a predetermined temperature, steam is formed, and the steam gradually enters the flash tank 18 through the steam pipe 32 and is supplied to a predetermined target by the position of the steam outlet valve 28; part of the steam in the flash tank 18 will condense into water, and the water vapor will separate, with the steam at the top and the water at the bottom; at this time, a part of the volume will gradually appear in the condenser 13, so that the water in the flash tank 18 is replenished to the condenser 13 under the action of gravity, and the steam pressure in the flash tank 13 is large. When the pressure in the flash tank 18 and the condenser 13 are unbalanced, the steam pressure will also push the water in the flash tank 18 into the condenser 13 to achieve water replenishment.

[0095] For further information, see Figure 1 , including a water supply pipe 35, the hot water pipe 34 is connected to the hot water pipe 34 and the flash tank 18 at the same time; a first water supply valve 19 is installed between the water supply pipe 35 and the hot water pipe 34; a second water supply valve 20 is installed between the water supply pipe 35 and the flash tank 18. At present, in order to ensure that the steam pressure is not too high, the unit must be stopped or the steam must be discharged when not in use, which causes a lot of waste. Therefore, the present invention can directly replenish water into the hot water pipe 34 or directly replenish water into the flash tank 18 through the water supply pipe 35, which directly brings about the completion of water replenishment, and the other effect brought about by the cold water added can play a role in cooling and preventing the steam pressure in the flash tank from being too high, and on the other hand, it avoids wasting energy by discharging steam; and the water added to the flash tank 18 can also be preheated in the flash tank 18, and after preheating, it is already at a high temperature when it is added to the condenser 13 through the return water pipe 33, and the added water is mixed more evenly. It also solves the current dilemma that when users do not need hot water / steam but need cold water / air, the whole machine cannot be shut down, as shutting down will affect the use of refrigeration, while not shutting down will result in the waste of steam.

[0096] Example 2

[0097] This embodiment 2 includes all the schemes of embodiment 1, and the oil-free centrifugal high-temperature heat pump unit, oil-free centrifugal high-temperature heat pump system and high-temperature heat pump method for cooling and heating of the present invention, further, see Figure 1 ,include:

[0098] The evaporator 17 obtains first low-temperature water, and makes the refrigerant exchange heat with the first low-temperature water; absorbs the heat of the water temperature by evaporation, and reduces the temperature of the first low-temperature water from the first low temperature to the second low temperature; more specifically, it includes: obtaining 12°C low-temperature water, and making the refrigerant exchange heat with the low-temperature water; absorbs the heat of the water temperature by evaporation, and outputs 7°C low-temperature water;

[0099] The low-pressure oil-free centrifugal compressor 11 obtains the low-temperature and low-pressure refrigerant from the evaporator 17 and compresses it into high-pressure and high-temperature refrigerant;

[0100] A high-pressure oil-free centrifugal compressor 12 receives the high-pressure and high-temperature refrigerant from the low-pressure oil-free centrifugal compressor 11 and further compresses it into a higher-pressure and high-temperature gaseous refrigerant. The high-pressure oil-free centrifugal compressor 12 has a different speed and number of stages from the low-pressure oil-free centrifugal compressor 11.

[0101] The condenser 13 obtains the second low-temperature water and receives the high-temperature and high-pressure refrigerant from the high-pressure oil-free centrifugal compressor 12; the high-temperature and high-pressure refrigerant is circulated with the second low-temperature water for heat exchange, heat is released, and the second low-temperature water is gradually heated to high-temperature water, so that the second low-temperature water is raised from the first temperature to the second temperature and output; more specifically, the second low-temperature water is heated to 120° C. by heat exchange and output;

[0102] The economizer 15 receives the refrigerant from the high-pressure oil-free centrifugal compressor 12 and outputs it in two parts. One part of the refrigerant is mixed with the refrigerant compressed by the low-pressure oil-free centrifugal compressor 11 and then enters the high-pressure oil-free centrifugal compressor. The other part of the refrigerant enters the evaporator 17 after the pressure is reduced for the second time by the low-pressure throttling device 16, completing the refrigeration and heating cycle.

[0103] Example 3

[0104] This embodiment 3 includes all the schemes of embodiment 1 and / or embodiment 2, and the oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating, the oil-free centrifugal high-temperature heat pump system for simultaneous cooling and heating, and the high-temperature heat pump simultaneous cooling and heating method of the present invention, further, see Figure 1, obtain first low-temperature water, and perform heat exchange between the first low-temperature water and the evaporator 17; realize that the first low-temperature water is reduced from the first low temperature to the second low temperature; more specifically, it includes: obtaining 12°C low-temperature water, and performing heat exchange between the low-temperature water and the refrigerant of the evaporator 17 to realize output of 7°C low-temperature water;

[0105] The low-pressure oil-free centrifugal compressor 11 is used to compress the low-temperature and low-pressure refrigerant from the evaporator 17 for the first time, and compresses it into high-pressure and high-temperature refrigerant;

[0106] The high-pressure and high-temperature refrigerant that has been compressed for the first time is compressed for the second time by using a high-pressure oil-free centrifugal compressor 12 with different rotation speeds and stages, so as to raise the refrigerant to a higher temperature;

[0107] Obtain second low-temperature water, perform heat exchange on the second low-temperature water using a higher-temperature refrigerant in the condenser, heat the second low-temperature water from the first temperature to the second temperature, and output the second low-temperature water as high-temperature water; more specifically, gradually heat the second low-temperature water to 120°C for output; wherein the high-pressure refrigerant is reduced in pressure twice and delivered to the evaporator 17; completing the refrigeration and heating cycle.

[0108] In addition to multi-stage compressors, increasing the speed can also improve the compression ratio; for the same compression ratio, the higher the speed, the smaller the number of stages can be; the lower the speed, the more stages are required. The low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 of the present invention are oil-free centrifugal compressors, which can achieve higher speeds and no wear. Therefore, when the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 are low-level compressors, they can also reach / exceed / approach the same or similar high temperature as the traditional 8-level compressor, and can save costs; therefore, the present invention can directly achieve the production of hot water exceeding 100°C by connecting the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 for two compressions. In addition, the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 of the present invention can use different speeds on the same unit / system, and additionally overcome the problem of different levels and different speeds of the same compressor at present.

[0109] The present invention realizes that the user does not need to provide a low-grade heat source above 30°C, and can also provide the user with hot water or steam above 100°C while meeting the user's refrigeration needs; it can provide the user with cold water / cold air while providing hot water / steam to achieve simultaneous hot and cold control, greatly expanding the scope of application;

[0110] Since the low-pressure oil-free centrifugal compressor 11 and the high-pressure oil-free centrifugal compressor 12 of the present invention are oil-free centrifugal compressors, the operation efficiency is higher, and the lubricating oil pipelines and components are omitted, and the volume of the unit is smaller;

[0111] The present invention also solves the problem that conventional equipment cannot produce high-temperature hot water above 100°C while producing low-temperature water of 7°C.

[0112] The words "first", "second" and similar words used in the specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantitative limitation, but rather indicate the presence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprises" include the elements or objects listed after "include" or "comprises" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0113] The preferred embodiments of the present invention described above are only the preferred embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the attached claims. For ordinary technicians in this field, other embodiments can be obtained according to the drawings without creative work, and any changes based on the claims of the present invention are within the protection scope of the present invention.

Claims

1. Oil-free centrifugal high-temperature heat pump unit with both cooling and heating, characterized in that: include: Evaporator; A low-pressure oil-free centrifugal compressor, which is connected to the evaporator through a suction line; A high-pressure oil-free centrifugal compressor, which is connected to the low-pressure oil-free centrifugal compressor through a compressor connecting pipeline; An economizer, the economizer is connected to the compressor connecting pipeline through an air supply pipeline; and the economizer is connected to the evaporator through a low-pressure throttling pipeline; A condenser, which is connected to the high-pressure oil-free centrifugal compressor through an exhaust pipeline; and the condenser is connected to the economizer through a high-pressure throttling pipeline; and the condenser is connected to the evaporator through a liquid bypass pipeline; the condenser is installed with a hot water pipeline, the water inlet end of the hot water pipeline is installed with a hot water inlet valve, the outlet end of the hot water pipeline is installed with a hot water outlet valve, and the hot water pipeline is connected with a steam pipeline; A flash tank having a steam outlet valve, the flash tank is connected to the steam pipe, and the steam pipe is equipped with a steam return valve; the flash tank has a return water pipe, the return water pipe is connected to the hot water pipe, and the hot water pipe is equipped with a hot water return valve.

2. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 1 is characterized in that: The high-pressure throttling pipeline between the condenser and the economizer is installed with a high-pressure throttling device; the low-pressure throttling pipeline is installed with a low-pressure throttling device.

3. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 2 is characterized in that: The high-pressure throttling pipeline is connected to a motor cooling pipeline; the motor cooling pipeline connects the low-pressure oil-free centrifugal compressor and the high-pressure oil-free centrifugal compressor; The motor cooling pipeline is provided with a high-pressure motor cooling throttling device at a position adjacent to the high-pressure oil-free centrifugal compressor; the motor cooling pipeline is provided with a low-pressure motor cooling throttling device at a position adjacent to the low-pressure oil-free centrifugal compressor.

4. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 1, characterized in that: The air supply pipeline is equipped with an intermediate air supply valve.

5. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 1, characterized in that: It comprises a liquid bypass pipeline, which is provided with a liquid supply bypass valve; one end of the liquid bypass pipeline is connected to the condenser, and the other end of the liquid bypass pipeline is connected to the evaporator.

6. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 1, characterized in that: It comprises a hot gas bypass pipeline, which is equipped with a hot gas bypass valve; one end of the hot gas bypass pipeline is connected to the exhaust pipeline, and the other end of the hot gas bypass pipeline is connected to the intake pipeline.

7. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 1, characterized in that: It includes a user plate changer; the user plate changer is connected to the hot water pipeline.

8. The oil-free centrifugal high-temperature heat pump unit for simultaneous cooling and heating according to claim 1 or 7, characterized in that: It comprises a water supply pipe, which is connected to the hot water pipe and the flash tank at the same time; a first water supply valve is installed between the water supply pipe and the hot water pipe; and a second water supply valve is installed between the water supply pipe and the flash tank.

9. Oil-free centrifugal high-temperature heat pump system with simultaneous cooling and heating, characterized in that: include: The evaporator obtains first low-temperature water and performs heat exchange between the refrigerant and the first low-temperature water; Absorbing heat from water temperature by evaporation, and reducing the temperature of the first low-temperature water from a first low temperature to a second low temperature; A low-pressure oil-free centrifugal compressor obtains the low-temperature and low-pressure refrigerant from the evaporator and compresses it into a high-pressure and high-temperature refrigerant; A high-pressure oil-free centrifugal compressor; receiving the high-pressure and high-temperature refrigerant from the low-pressure oil-free centrifugal compressor and further compressing it into a higher-pressure and high-temperature gaseous refrigerant, wherein the high-pressure oil-free centrifugal compressor and the low-pressure oil-free centrifugal compressor have different speeds and stages; A condenser obtains the second low-temperature water and receives the high-temperature and high-pressure refrigerant from the high-pressure oil-free centrifugal compressor; performs heat exchange between the high-temperature and high-pressure refrigerant and the second low-temperature water cycle, releases heat, gradually heats the second low-temperature water to high-temperature water, and raises the second low-temperature water from the first temperature to the second temperature and outputs it; The high-pressure refrigerant is reduced in pressure for the first time through a high-pressure throttling device and delivered to the economizer; the economizer receives the refrigerant from the high-pressure oil-free centrifugal compressor and outputs it in two parts, one part of the refrigerant is mixed with the refrigerant compressed by the low-pressure oil-free centrifugal compressor and then enters the high-pressure oil-free centrifugal compressor, and the other part of the refrigerant enters the evaporator after the pressure is reduced for the second time through the low-pressure throttling device, completing the refrigeration and heating cycle.

10. A high-temperature heat pump cooling and heating method, characterized in that: The oil-free centrifugal high-temperature heat pump unit for cooling and heating is used as described in claims 1 to 8. Obtaining first low-temperature water, and performing heat exchange between the first low-temperature water and the evaporator; Realize that the first low-temperature water is cooled from a first low temperature to a second low temperature; Using a low-pressure oil-free centrifugal compressor to perform a first compression on the low-temperature and low-pressure refrigerant from the evaporator and compress it into a high-pressure and high-temperature refrigerant; The high-pressure and high-temperature refrigerant that has been compressed for the first time is compressed for the second time by using a high-pressure oil-free centrifugal compressor with different speeds and stages, so as to raise the refrigerant to a higher temperature; Obtain second low-temperature water, perform heat exchange on the second low-temperature water using a higher-temperature refrigerant in a condenser, heat the second low-temperature water from the first temperature to the second temperature, and output the second low-temperature water as high-temperature water; wherein the high-pressure refrigerant is reduced in pressure twice and delivered to the evaporator; and complete the refrigeration and heating cycle.

11. The high temperature heat pump cooling and heating method according to claim 10, characterized in that: Obtaining steam of high-temperature water having a second temperature, and supplying the steam to a flash tank, so that the steam is separated from water vapor in the flash tank; The water in the flash tank is first replenished to the condenser under the action of gravity; When the pressure in the flash tank and the condenser is unbalanced, the steam pressure in the flash tank is used to replenish the water in the flash tank into the condenser for a second time to achieve water replenishment.

12. The high temperature heat pump cooling and heating method according to claim 11, characterized in that: Add water to the flash tank, use the added cold water to cool the flash tank and prevent the steam pressure in the flash tank from being too high; and use the steam in the flash tank to preheat the water; Add the preheated water into the condenser to make the added water mixed more evenly.

13. The high temperature heat pump cooling and heating method according to claim 10, characterized in that: The low-pressure oil-free centrifugal compressor and the high-pressure oil-free centrifugal compressor respectively use different rotation speeds.

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