Wide-temperature-range high-temperature heat pump unit
By introducing a subcooler and low-pressure high-temperature refrigerant R515B into the high-temperature heat pump system, the problem of efficient operation on the low-temperature source side is solved, realizing a high-efficiency, low-cost wide-temperature-range high-temperature heat pump unit suitable for various heating and cooling applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2026-04-03
AI Technical Summary
Existing high-temperature heat pump systems are inefficient and costly under low-temperature source conditions, and the increased heat exchanger area when using high-pressure, high-temperature refrigerants further increases costs.
It employs a subcooler and low-pressure high-temperature refrigerant. The subcooler reduces the temperature of the liquid refrigerant before the expansion valve, increases the degree of subcooling, and reduces the superheating heat exchange area in the evaporator. It uses R515B refrigerant with an ODP of 0 and a GWP of 299.
It improves system efficiency by about 4% and reduces costs by about 4-5% over a wide temperature range, meets the application temperature requirements of 40℃ to 100℃ at a source side temperature of 10℃~60℃, is suitable for industrial waste heat resources and low-temperature source side applications, reduces heat exchanger area by 11%, and reduces unit costs.
Smart Images
Figure CN224080440U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of high-temperature heat pump technology, and in particular to a wide-temperature-range high-temperature heat pump unit. Background Technology
[0002] In existing ground-source high-temperature heat pump technologies, a single-stage compression system using a single refrigerant requires a source-side temperature above 25°C to achieve a user-side temperature above 85°C. While a two-stage compression system using a single refrigerant can achieve a maximum outlet water temperature of 90°C at a source-side temperature of around 15°C, it involves more auxiliary components and is more complex. Cascade systems can also achieve user-side temperatures above 90°C at lower source-side temperatures, but these systems are even more complex, have a relatively higher failure rate, and are more expensive. Furthermore, existing single-stage high-temperature heat pump systems use low-pressure high-temperature refrigerants. Compared to refrigerants that have been maturely applied for many years due to environmental regulations, low-pressure high-temperature refrigerants have a higher dryness. Under the same design conditions, the heat exchanger area used for superheating needs to be increased accordingly to ensure sufficient heat exchange, leading to an increase in heat pump unit cost of approximately 4-5%. Utility Model Content
[0003] The purpose of this invention is to provide a wide-temperature-range high-temperature heat pump unit to solve the problems mentioned in the background art.
[0004] A wide-temperature-range high-temperature heat pump unit includes a compressor, a condenser, a subcooler, and an evaporator: the exhaust port of the compressor is connected to the inlet of the condenser, the liquid outlet of the condenser is connected to the liquid inlet of the subcooler, a drying filter is installed between the condenser and the subcooler piping, the liquid outlet of the subcooler is connected to the liquid inlet of the evaporator, a throttling valve is installed between the subcooler and the evaporator, and the exhaust port of the evaporator is connected to the inlet of the compressor.
[0005] As a further description of the above technical solution:
[0006] The condenser has a condensate inlet and a condensate outlet on its side.
[0007] As a further description of the above technical solution:
[0008] An extension pipe is fixedly connected to the bottom of the condenser. The end of the extension pipe is connected to the liquid inlet of the subcooler. A second dryer filter and a second throttle valve are installed in the middle section of the extension pipe. The distance between the second dryer filter and the condenser is less than the distance between the second throttle valve and the condenser.
[0009] As a further description of the above technical solution:
[0010] The outlet of the subcooler is connected to a return pipe, the end of which is connected to the gas supply end of the compressor, and a ball valve is provided at the middle end of the return pipe.
[0011] As a further description of the above technical solution:
[0012] The evaporator shell is provided with an evaporation outlet and an evaporation inlet.
[0013] The beneficial effects of this utility model are:
[0014] By installing a subcooler, the temperature of the liquid refrigerant before the expansion valve is reduced. Whether in high-temperature heating conditions of 90℃~100℃ or in cooling conditions, the subcooling degree of the system is increased, the dryness degree is reduced, and the energy efficiency is improved by about 4%. The heat exchange area used for superheating in the evaporator is reduced in high-temperature heating conditions, and the cost of the unit is reduced by about 4~5%.
[0015] This allows the unit to provide a temperature range of 40°C to 100°C on the operating side when the source side temperature is between 10°C and 60°C; and when the source side temperature is between 12°C and 20°C, the maximum operating temperature on the operating side can reach 90°C to 100°C.
[0016] This unit can be used in applications with industrial waste heat resources or in situations where the source-side temperature is low. It solves the problem that existing high-temperature heat pumps require waste heat resources above 30°C to operate efficiently at heating temperatures of 85°C to 100°C. In addition to meeting heating and process requirements of 40°C to 100°C, this unit can also meet cooling requirements as low as 5°C, providing cooling capacity for buildings or refrigerated processes. Attached Figure Description
[0017] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:
[0018] Figure 1 This is a schematic diagram of the wide-temperature-range high-temperature heat pump unit system of this utility model;
[0019] Figure 2 A diagram comparing the condenser's built-in 5°C cooling and the subcooler's 10°C cooling;
[0020] Figure 3 This diagram illustrates the reduction in dryness when the condenser has a built-in 5°C cooler and when a subcooler is used, resulting in a 10°C cooler.
[0021] In the diagram: 10, compressor; 20, condenser; 21, condensate inlet; 22, condensate outlet; 23, dryer filter one; 30, subcooler; 31, throttle valve one; 40, evaporator; 41, evaporator inlet; 42, evaporator outlet; 50, extension piping; 51, dryer filter two; 52, throttle valve two; 60, return piping; 61, ball valve. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0024] In practical implementation: such as Figure 1-3 As shown, a wide-temperature-range high-temperature heat pump unit includes a compressor 10, a condenser 20, a subcooler 30, and an evaporator 40.
[0025] The exhaust port of compressor 10 is connected to the inlet port of condenser 20;
[0026] The liquid outlet of condenser 20 is connected to the liquid inlet of subcooler 30;
[0027] The condenser 20 has a condensate inlet 21 and a condensate outlet 22 on its side.
[0028] A dryer filter 23 is installed between the pipes of condenser 20 and subcooler 30;
[0029] The high-temperature and high-pressure refrigerant gas discharged from the compressor 10 enters the condenser 20. The condenser 20 then converts the high-temperature and high-pressure refrigerant gas into a high-temperature and high-pressure refrigerant liquid. The high-temperature and high-pressure refrigerant liquid is then dried and filtered by the dryer filter 23 before entering the interior of the subcooler 30. The subcooler 30 can further reduce the temperature of the high-temperature and high-pressure refrigerant liquid and reduce the dryness of the refrigerant liquid after the expansion valve 31.
[0030] This unit uses a low-pressure, high-temperature refrigerant with an Ozone Depletion Potential (ODP) of 0 and a Global Warming Potential (GWP) of 299. By installing a subcooler 30, the system lowers the temperature of the liquid refrigerant before the expansion valve 31. This increases the subcooling degree of the system and reduces the dryness after the expansion valve 31, whether in high-temperature heating conditions (90℃~100℃) or cooling conditions, thus improving energy efficiency by about 4%. It also reduces the heat exchange area used for superheating in the evaporator 40 under high-temperature heating conditions, and reduces the unit cost by about 4~5%.
[0031] An extension pipe 50 is fixedly connected to the bottom of the condenser 20. The end of the extension pipe 50 is connected to the outlet of the subcooler 30. A second dryer filter 51 and a second throttle valve 52 are installed in the middle section of the extension pipe 50. The distance between the second dryer filter 51 and the condenser 20 is less than the distance between the second throttle valve 52 and the condenser 20.
[0032] The dryer filter 251 can filter impurities in the refrigerant system and maintain the dryness of the refrigerant system.
[0033] The outlet end of the subcooler 30 is connected to a return pipe 60, the end of the return pipe 60 is connected to the gas supply end of the compressor 10, and a ball valve 61 is provided at the middle end of the return pipe 60.
[0034] The shell of the evaporator 40 is provided with an evaporation outlet 42 and an evaporation inlet 41.
[0035] The liquid outlet of the subcooler 30 is connected to the liquid inlet of the evaporator 40;
[0036] A throttling valve 31 is provided between the subcooler 30 and the evaporator 40, and the outlet of the evaporator 40 is connected to the inlet of the compressor 10.
[0037] Please see Figure 2 Under the condition of a source-side water temperature of 30℃ and a user-side water temperature of 80℃, a comparison was made between the condenser 20 with 5% supercooling and the condenser 30 with 10% supercooling, without supercooler 30. The enthalpy difference increased by 2.8%, the refrigerant cooling flow rate increased by 7.2%, the heat output increased by 8%, the power increased by 4.9%, and the COP increased by 3%.
[0038] Theoretical calculations show that R515B low-pressure, high-temperature refrigerant has a 3-5% higher dryness fraction than R134a refrigerant under the same operating conditions. Due to this higher dryness, the heat exchange area for the refrigerant gas in the heat exchanger needs to be larger. Furthermore, the heat transfer coefficient of refrigerant gas differs by several times compared to that of refrigerant liquid. This means that the heat exchanger area needs to be increased by several times to achieve the same heat exchange effect as the refrigerant, which has been used effectively for many years.
[0039] Please see Figure 3 Under the condition of a source-side water temperature of 30℃ and a user-side water temperature of 80℃, the dryness fraction "(h-h1) / (h2-h1)" without a subcooler is 11% greater than that with a subcooler "(h'-h1) / (h2-h1)". This indicates that after adding a subcooler, the area used for superheated gas heat exchange in the evaporator of the R515B refrigerant system can be reduced by 11%.
[0040] It can be concluded that under this operating condition, the heat exchange area of the evaporator can be made smaller for equipment with and without subcooler 30. By setting subcooler 30 before the throttle valve, the dryness can be reduced, the area used for heat exchange of gaseous refrigerant can be reduced, and the proportion of liquid heat exchange can be increased. This can reduce the area of heat exchanger used for superheating due to the increase in dryness.
[0041] For heat pump equipment, the main costs of the heat pump unit can be divided into: compressor, heat exchanger, refrigeration system components, labor, and others. If we calculate the heat exchanger cost as accounting for 1 / 3 of the total cost, then the evaporator cost accounts for 1 / 6 of the total cost. By employing a subcooler design, the heat exchange area used for superheating within the evaporator is reduced, thereby lowering the cost of the evaporator and thus reducing the overall cost of the unit.
[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.
[0043] In this specification, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0044] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.
Claims
1. A wide-temperature-range high-temperature heat pump unit, characterized in that, The application relates to a refrigeration system, which comprises a compressor (10), a condenser (20), a supercooler (30) and an evaporator (40); the exhaust port of the compressor (10) is connected with the air inlet of the condenser (20), the liquid outlet of the condenser (20) is connected with the liquid inlet of the supercooler (30), a dry filter (23) is arranged between the condenser (20) and the supercooler (30), the liquid outlet of the supercooler (30) is connected with the liquid inlet of the evaporator (40), a throttle valve (31) is arranged between the supercooler (30) and the evaporator (40), and the air outlet of the evaporator (40) is connected with the air inlet of the compressor (10). The bottom of the condenser (20) is fixedly connected with an extension pipeline (50), the tail end of the extension pipeline (50) is connected with the liquid inlet of the supercooler (30), the middle section of the extension pipeline (50) is provided with a dry filter (51) and a throttle valve (52), and the distance between the dry filter (51) and the condenser (20) is smaller than the distance between the throttle valve (52) and the condenser (20). The air outlet end of the supercooler (30) is connected with a backflow pipeline (60), the tail end of the backflow pipeline (60) is connected with the air supplement end of the compressor (10), and the middle end of the backflow pipeline (60) is provided with a ball valve (61).
2. The wide-temperature-range high-temperature heat pump unit according to claim 1, characterized in that: The side of the condenser (20) is respectively provided with a condensing water inlet (21) and a condensing water outlet (22).
3. The wide-temperature-range high-temperature heat pump unit according to claim 1, characterized in that: The shell of the evaporator (40) is respectively provided with an evaporating water outlet (42) and an evaporating water inlet (41).