Compressor and cooling method thereof by capillary pressure differential automatic liquid spray cooling

Abstract

The compressor and cooling method thereof are characterized in that: the compressor main body is provided with a differential pressure liquid spray cooler which is inserted into the compressor main body and fixed thereto; the outlet pipe of the condenser filled with refrigerant is connected with the differential pressure liquid spray cooler, so that the outlet pipe of the condenser is directly communicated with the cylinder compression cavity of the compressor through the differential pressure liquid spray cooler; the capillary tube of the differential pressure liquid spray cooler is used for delivering the quantitative refrigerant to the cylinder compression cavity under the action of the differential pressure; under the condition that the condensing temperature corresponding to the refrigerant type is determined, the displacement of the compressor is selected, and the frequency of the compressor is determined, the relationship between the inner diameter and the length of the capillary tube is determined by a, and the range of the a is 0.2-7. The compressor is used for the automatic liquid spray cooling through the capillary tube differential pressure.

Description

Technical Field

[0001] This invention relates to an improvement on a low-temperature refrigeration compressor, and more particularly to a compressor that automatically injects refrigerant based on refrigerant pressure difference to effectively reduce the internal temperature of the compressor cylinder, and a corresponding method for automatically reducing the temperature of the compression chamber. Background Technology

[0002] Refrigerants have two parameters affecting the Earth's environment: one is ODP (Ozone Layer Depletion Factor), where a higher ODP value directly damages the ozone layer. The other concept is GWP (Global Warming Factor), a value obtained by comparing it with CO2. While a high GWP value does not directly damage the ozone layer, greenhouse gases will remain in the atmosphere, absorbing heat.

[0003] As a replacement for R134a refrigerant in automotive air conditioning systems, HFO refrigerant R1234yf will expand its application range to include newly manufactured medium-sized buses, heavy-duty trucks, and vans.

[0004] In Europe and North America, refrigerated and frozen products are generally manufactured and sold by purchasing compressors and assembling them locally. The compressor is a crucial component of a refrigeration and frozen system; without this core component, the system cannot function. Refrigeration and frozen product compressors typically have a condensing temperature of 54.4 degrees Celsius and an evaporating temperature of -23.3 degrees Celsius. With traditional refrigerant R22 and the semi-alternative R404A, when using a single compressor, the large temperature difference between evaporation and condensation leads to a significant difference in evaporation and condensation pressures. A high compression ratio in the compressor results in excessively high exhaust temperatures. Furthermore, the insulation withstand temperature of the compressor motor is approximately 125 degrees Celsius; temperatures exceeding 120 degrees Celsius may cause electrical insulation damage.

[0005] Traditional refrigeration systems use compressors with low evaporation temperatures, resulting in high compression ratios and high exhaust temperatures. With increasing international environmental requirements and improved refrigeration equipment performance, existing refrigerants like R22 are gradually being phased out in the high-end market. This refrigerant switch necessitates the use of new refrigerants in refrigeration systems. These new refrigerants differ from the original R22 in pressure, density, and viscosity. When compressors previously using R22 are switched to R449A, R513A, or even newer refrigerants soon to be phased out in the US and Europe, the exhaust temperature exceeds the motor insulation's tolerance. Upon startup, the high compression ratio of the existing equipment causes a rapid temperature rise within the compressor, leading to insulation damage and ultimately, compressor failure.

[0006] Several comparative documents provide methods and structures for reducing the temperature in the compression zone through injection cooling. However, simply transplanting existing injection cooling structures to new refrigerant compressors is not feasible. This could lead to problems such as excessively high exhaust temperatures, limiting the compressor's operating range, or excessively low exhaust temperatures, resulting in significant compressor capacity loss and poor efficiency. Furthermore, the complexity of the adaptation structure severely impacts reliability, rendering it unusable. Summary of the Invention

[0007] The purpose of this invention is to provide a compressor that automatically cools itself by capillary pressure differential injection and a cooling method thereof, particularly a compressor that reduces the temperature of the cylinder compression zone by changing the capillary parameters to suit different types of new refrigerants through pressure differential injection cooling, and a corresponding cooling method thereof.

[0008] The objective of this invention is achieved as follows: A compressor with automatic capillary pressure differential liquid injection cooling comprises: a compressor body; a pressure differential liquid injection cooler inserted into and fixed to the compressor body; and an outlet pipe of a condenser containing refrigerant connected to the pressure differential liquid injection cooler, such that the condenser outlet pipe is directly connected to the cylinder compression chamber of the compressor via the pressure differential liquid injection cooler. The capillary tube of the pressure differential liquid injection cooler delivers a fixed amount of refrigerant to the cylinder compression chamber under the action of pressure differential. Given a determined condensation temperature corresponding to the refrigerant type, a selected compressor with confirmed displacement and compressor frequency, the relationship between the inner diameter and length of the capillary tube is determined by 'a', where 'a' ranges from 0.2 to 7. In the above formula, d represents the equivalent diameter of the capillary tube, in millimeters; L represents the length of the capillary tube, in meters; ΔP represents the pressure difference between the condensing saturation pressure and the evaporating saturation pressure when the condensing temperature is 54.4℃ and the evaporating temperature is -23.3℃. This parameter is determined according to different types of refrigerants, in MPa; b represents the compressor displacement (in milliliters) / 10; f represents the compressor frequency, for variable frequency compressors it refers to 80Hz, in Hertz.

[0009] The compressor, which is automatically cooled by capillary differential pressure injection, has an inlet hole for installing a differential pressure injection cooler on its main body. The injection device of the differential pressure injection cooler is connected to the outlet of the capillary tube, and the inlet of the capillary tube is connected to the inlet component of the differential pressure injection cooler.

[0010] When the refrigerant is R410A, the optimal range of a is 1.3-2.0; when the refrigerant is R513A, the optimal range of a is 0.3-1.0; when the refrigerant is R449A, the range of a has two parallel groups: the first group is 0.8-1.6 and the second group is 1.8-3.0; when the refrigerant is R455A, the optimal range of a is 0.7-2.0; or when the refrigerant is R448A, the optimal range of a is 1.8-3.0; or when the refrigerant is R290, the optimal range of a is 0.7-0.9; or when the refrigerant is R454C, the optimal range of a is 1.2-1.6.

[0011] The compressor cooling method involves installing a differential pressure liquid spray cooler on the compressor cylinder. This cooler is connected to the condenser outlet pipe containing refrigerant. The capillary tube of the cooler, under the influence of the pressure difference, delivers the refrigerant to the cylinder compression chamber, thus cooling the compression space within the compressor. The pressure difference depends on parameter 'a', which is related to the capillary tube inner diameter and length, condensing temperature, compressor displacement, and compressor frequency. The range of 'a' is 0.2–7.

[0012] In the above formula, d represents the equivalent diameter of the capillary tube, in millimeters; L represents the length of the capillary tube, in meters. ΔP represents the pressure difference between the condensing saturation pressure and the evaporating saturation pressure when the condensing temperature is 54.4℃ and the evaporating temperature is -23.3℃. This parameter is determined according to different types of refrigerants and is in MPa; b represents the compressor displacement (unit: ml) / 10; f represents the compressor frequency, which is 80Hz for variable frequency compressors and is in Hertz.

[0013] Beneficial effects: This invention addresses the problem that existing high-compression-ratio compressors using R22 refrigerant cannot adapt to the high temperatures generated by the compression of new refrigerants. It provides a solution for externally spraying low-temperature refrigerant. By injecting refrigerant into the compression space of the existing cylinder (e.g., using R22) in a timely manner through pressure difference, the problem of sudden temperature rise in the cylinder when using new refrigerant is solved, protecting the equipment insulation and ensuring the normal operation of the system.

[0014] Currently, China accounts for 86.5% of the global compressor production capacity and is also a major supplier of compressors for refrigeration and freezing products to North America and Europe. Providing customers with compressor products that comply with local laws, regulations, and environmental requirements is a crucial issue and a key indicator of whether compressor manufacturers can gain customer approval and generate foreign exchange for exports.

[0015] Since frozen and refrigerated products have high compression ratios and high exhaust temperatures, the core of this invention is to inject the condensed refrigerant into the compressor's compression chamber in a timely manner through a liquid spray cooling component, thereby reducing the compressor's exhaust temperature.

[0016] Because the same compressor uses different refrigerants during the operation of the refrigeration system, it will exhibit different temperature conditions. Traditional compressors can only be charged with one type of refrigerant throughout their lifespan. Therefore, it is very important to ensure that the compressor can work normally for different types of refrigerants required by customers without changing the main mechanical structure of the compressor, control the discharge temperature, and enable the compressor to continue to operate normally while maintaining a relatively high cooling capacity and reliability.

[0017] This invention achieves a significant technological breakthrough by adjusting the diameter and length of the capillary tube. Through theoretical analysis and experimental research, this invention overcomes technical bottlenecks and provides a reliable technical solution for refrigeration and cold storage compressors with a liquid spray cooling system adapted to new refrigerants.

[0018] Refrigeration is the process by which refrigerant, compressed by a compressor, flows into the condenser inlet, releases heat in the condenser to reduce its enthalpy, passes through a system throttling device to reduce its pressure, enters the evaporator to absorb heat, and achieves refrigeration. Then, it returns from the evaporator outlet to the compressor inlet, completing one refrigeration cycle.

[0019] Traditional compressor spray cooling technology lacks suitable or near-ideal improvement solutions for existing Chinese models. Completely eliminating existing domestic production lines—for example, upgrading to meet high-end and international emission standards using spray cooling solutions applicable to R32 (as described in the comparison document) would essentially render many compressor manufacturers' existing refrigerant-compatible mechanical production lines obsolete. This upgrade process would require substantial costs for intellectual property acquisition and equipment purchases.

[0020] This invention, while preserving the original production line, revitalizes it by adjusting the capillary tube to manufacture a compressor that fully meets high-end and international emission requirements and can adapt to various new refrigerants. Fourth, by providing capillary tube parameters and employing a differential pressure automatic injection process, this invention effectively reduces the temperature of the compression chamber, overcoming the problem that traditional compressors cannot operate with various new refrigerants with different performance characteristics at high compression ratios. It allows for cost-effective upgrades to accommodate different refrigerants by adjusting the capillary tube according to the selected compressor parameters and the customer's required refrigerant type. This changes the current situation where a single-structure compressor can only use one type of refrigerant, expanding the refrigerant application range of compressors with the same structure, adapting to the continuous upgrading of refrigerants, effectively reducing costs to keep pace with international advancements, and improving performance while maintaining the cost of existing low-temperature compressor products. It eliminates the need to build continuously upgrading production lines, providing higher-quality compressors to people worldwide at a lower cost.

[0021] Through practical testing and theoretical verification, this invention, by accurately controlling the relationship between capillary tube specifications, compressor displacement, and frequency, and precisely applying differential pressure cooling, can instantly and in real time reduce the compressor's exhaust temperature while maximizing the preservation of the refrigeration system's operational capacity.

[0022] This invention identifies the specific reason why traditional compressors cannot operate with the new refrigerant at high compression ratios and fail immediately, and provides a solution to this problem. It broadens the refrigerant application range of existing compressors and provides a way for existing low-temperature compressors to use the new refrigeration system. With precise improvements to the capillary tube, compressors using the new refrigerant can be produced on existing domestic production lines, allowing them to enter the high-end and international markets at lower prices than international standards, while maintaining their existing market share.

[0023] To reduce exhaust temperature, this invention adds a method to directly inject a small amount of refrigerant working fluid into the compressor compression chamber through a set pressure difference from the condenser outlet liquid spray cooling pipe. By utilizing the cooling characteristics of this part of the working fluid injected into the compression chamber, the heat caused by high pressure ratio, motor heating and friction heating during the compression process is reduced, so that the exhaust temperature of the compressor reaches the range that the motor insulation can withstand, resulting in a high-quality industrial product.

[0024] This invention identifies and confirms that, for the temperature influence factors of new refrigerants used in existing domestically produced compressors, once the compressor parameters and refrigerant type are determined, this problem can be completely solved by selecting the size of a capillary tube. Through extensive analysis, experimental verification, screening, and further experiments, the relationship between various temperature influence factors and structural parameter 'a' when using mainstream new refrigerants was finally summarized. The optimal range of 'a' and its calculation method were also determined. This invention opens up a new approach for the same type of domestically produced compressor to operate normally with different types of refrigerants.

[0025] The cooling system used in this invention has an inlet that is welded to the pipes that have been condensed from the condenser, bringing the refrigerant into the system. The injection device is used to automatically extract a portion of the refrigerant from the inlet and through the capillary tube according to the calculated amount, and inject it into the injection hole that communicates with the compressor's compression chamber. The cooling capacity of this extracted refrigerant is used to reduce the compressor's exhaust temperature.

[0026] The size changes and pressure difference of the capillary tube determine the amount of refrigerant entering the compressor's compression chamber to lower the compressor's discharge temperature. If the inner diameter of the liquid-cooled capillary tube is large and its length is short, the corresponding compressor displacement will be small, and the refrigerant discharge temperature will be low. This will result in an excessive amount of refrigerant entering the compressor's compression chamber, which will first affect the overall refrigeration cycle's capacity. It may even make it difficult to achieve the condensing temperature, which determines the environmental conditions under which the refrigeration system can still operate normally.

[0027] Generally speaking, a condensing temperature of 54.5 degrees Celsius ensures that the refrigeration system can operate normally when the ambient temperature of the outdoor unit is below 45 degrees Celsius. If the condensing temperature does not reach this level, the refrigeration system may not function properly when the ambient temperature is higher. This is obviously quite problematic.

[0028] After several assessments and practical verifications, it has been found that only when the inner diameter and length of the liquid-injected cooling capillary tube, the compressor displacement, and the refrigerant characteristic factor meet the specific relationships described in this invention can the compressor with a liquid-injected cooling zone system corresponding to that refrigerant provide products with better performance, have the stability to work normally under various refrigerants, generate high cooling capacity, and have high equipment energy efficiency.

[0029] It is important to note that although extensive industrial testing has been conducted, slight fluctuations in evaporation and condensation pressures between different batches of the same refrigerant can occur during actual use. The refrigerant injected into the compressor's compression chamber via the liquid-jet cooling system is driven by the pressure difference between evaporation and condensation, automatically achieved through the liquid-jet cooling capillary. Therefore, the selection of the capillary in this invention takes into account various influencing factors and provides a certain range to ensure normal operation under different conditions. Thus, the selection of the capillary is crucial to the usability of the compressor with the liquid-jet cooling system, the refrigeration system's performance characteristics, and its compatibility with environmental conditions.

[0030] Because compressors with liquid injection cooling systems involve various factors, including the heat generated by the motor under different operating conditions, differences in pump body frictional heat generation due to voltage and frequency fluctuations, differences in heat increase caused by changes in the compressible internal energy of the same type of refrigerant from different manufacturers, and factors such as the compressor's ambient temperature and operating conditions, as well as changes in the viscosity and flowability of the working fluid under different conditions, these are complex factors that are difficult to obtain directly through simple calculations. Calculated results may differ significantly from actual conditions after practical verification. Through comprehensive experimental research and customer product feedback, and after various analyses and corrections, it has been confirmed that low-temperature refrigeration compressors with liquid injection cooling systems manufactured according to the scope of this invention can guarantee normal operation when adapted to new refrigerants. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a compressor with liquid injection cooling. (Attached) Figure 2 yes Figure 1 A magnified view of a portion of the cooling system. (Attached) Figure 3 This is a structural diagram of the spray cooling system before installation. Detailed Implementation Example

[0032] A compressor with automatic capillary differential pressure injection cooling comprises: a compressor body 1 containing the original refrigerant; an inlet hole 2 for mounting a differential pressure injection cooler; an injection device 3 of the differential pressure injection cooler connected to the outlet of a capillary tube 4; the inlet of the capillary tube 4 connected to the inlet component 5 of the differential pressure injection cooler; and the injection device 3 of the differential pressure injection cooler inserted into and fixed to the compressor body, for example, by an interference fit. The inlet hole 2, extending beyond the length of the injection device, can be an oblique hole, an arc-shaped hole, or an L-shaped hole. In actual machining, L-shaped holes are easier to machine, have the smallest injection nozzle on the bearing end face, and facilitate performance testing. Oblique holes are better than arc-shaped holes, and both are better than L-shaped holes.

[0033] After the outlet pipe of the condenser containing refrigerant is connected to the differential pressure injection cooler, the refrigerant in the condenser passes through the channel of the differential pressure injection cooler that is directly connected to the cylinder compression chamber 6 of the compressor. During the rotation of the rotating part 7 of the compressor, under the action of differential pressure, it enters the compression chamber in a pulsating manner, effectively reducing the temperature of the compression zone.

[0034] The compressor cooling method involves installing a differential pressure liquid spray cooler on the compressor cylinder. This cooler is connected to the condenser outlet pipe containing refrigerant. The capillary tube of the cooler, under the influence of the pressure difference, delivers the refrigerant to the cylinder compression chamber, thus cooling the compression space within the compressor. The pressure difference depends on parameter 'a', which is related to the capillary tube inner diameter and length, condensing temperature, compressor displacement, and compressor frequency. The range of 'a' is 0.2–7.

[0035] In the above formula, d represents the equivalent diameter of the capillary tube, in millimeters; L represents the length of the capillary tube, in meters. ΔP represents the pressure difference between the condensing saturation pressure and the evaporating saturation pressure when the condensing temperature is 54.4℃ and the evaporating temperature is -23.3℃. This parameter is determined according to different types of refrigerants and is in MPa. b represents the compressor displacement (unit: ml) / 10; f represents the compressor frequency, with variable frequency compressors referring to 80Hz, unit: Hertz.

[0036] Example 2: The compressor with automatic liquid injection cooling via capillary pressure difference described in Example 1 can operate normally within the range of 0.2 to 2 when using conventional refrigerant, providing a high-quality refrigerant and fulfilling the operational requirements.

[0037] A larger value indicates that more cooling refrigerant is entering, resulting in a better cooling effect; a smaller value indicates better economic performance in refrigeration. Different products can be customized according to product performance requirements and user requirements.

[0038] The compressor with the parameters of this invention has better energy efficiency and a wider range of usable operating conditions (evaporation and condensation temperatures). This invention confirms the correspondence between capillary tubes, displacement, and refrigerant frequency, facilitating the matching of appropriate capillary tubes to different types of refrigerants. This allows the compressor to adapt to a wider range of refrigerants, keeping pace with the continuous innovation of international refrigerants.

[0039] The differential pressure liquid injection cooler includes an inlet component, a capillary tube connected to the inlet component, and an injection device connected to the capillary tube outlet. The compressor body has an inlet hole for installing the differential pressure liquid injection cooler. The injection device of the differential pressure liquid injection cooler is connected to the capillary tube outlet, and the capillary tube inlet is connected to the inlet component of the differential pressure liquid injection cooler. In this compressor with automatic differential pressure liquid injection cooling via capillary tube, the refrigerant can be R513A, R455A, R448A, R449A, R290, or R454C; it is also compatible with currently used R404A, R410A, etc., allowing one compressor to use multiple refrigerants. The value of 'a' ranges from 0.2 to 2.

[0040] The compressor described above uses a capillary tube manufactured through stretching. During the stretching process, the tube diameter may become uneven. Therefore, a certain length can reduce the throughput error caused by changes in the tube diameter.

[0041] Handmade clip making: Cut the glass blank into the required length, and then make one end into a cone shape by hand, which is called clip forming capillary in capillary processing: Heat the made clip to about 1200°C, and then cool it down slightly to 1100°C to stretch the clip head into a thin tube. After the capillary cools down and fixes its shape, the stretching is repeated. This process is repeated until the required diameter and length are achieved.

[0042] End treatment: Both ends of the capillary are melted with a torch to make them uniform. The precision requirements for capillary processing are extremely high. Typical production lines can produce capillary tubes with a diameter of approximately 0.12 mm, while higher precision requires sophisticated equipment and technology. For example, in the medical field, the capillary tubes used in blood glucose test strips have a diameter of only about 0.6 mm, and the process from preparation to finished product requires multiple quality controls and tests to ensure reliable quality and high precision.

[0043] In the experiment, the evaporation-condensation pressure difference under standard operating conditions for this refrigerant essentially represents a constant relationship between displacement and flux. This application aims to protect precisely this type of compressor, which can adapt to different refrigerants by adjusting the size of the capillary tube and the displacement-frequency pressure difference relationship.

[0044] Example 3: In the compressor with automatic liquid injection cooling via capillary pressure difference described in Example 1 or 2, when the refrigerant is R513A, the optimal range of α in this combination is 0.3-1.0, with the optimal value being 0.7-0.8. To illustrate with specific examples It is matched with a C-*RVN153LXX model compressor with a frequency of 80Hz and a displacement of 32cc. The condenser refrigerant outlet temperature is 32.2℃, and its theoretical discharge temperature is 95.3℃. When the actual discharge temperature is set to 80℃, the enthalpy difference 1 of the compressor cycle is 131; the enthalpy difference 2 between theoretical discharge and actual discharge is 23; the heat obtained by 32cc 80Hz 1S liquid injection cooling is 351.8W; the theoretical injection mass is 2.67g / s; and the evaporation-condensation pressure difference is 1.4Mpa.

[0045]

[0046] As shown in the table above, you can choose capillary tubes with an inner diameter of 1.2mm and a length of 0.8m or capillary tubes with an inner diameter of 1.42mm and a length of 1.2-1.3m. The economical option is to use a liquid-cooled capillary tube with an equivalent inner diameter of 1.2mm and a length of 800mm (0.8m).

[0047] BThe same refrigerant: It is matched with a C-*RHN75EXX model compressor with a frequency of 50HZ; a displacement of 13.3cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 95.3 degrees Celsius. When the actual discharge temperature is set to 80 degrees Celsius, the enthalpy difference 1 of one cycle of the compressor is 131KJ / Kg; the enthalpy difference 2 between theoretical discharge and actual discharge is 23KJ / Kg; and the heat obtained by the 13.3cc 50Hz 1S liquid injection cooling is 91W; the theoretical spray mass is 0.69g / s; and the evaporation-condensation pressure difference is 1.4Mpa.

[0048] As can be seen from the table above, a liquid-cooled capillary tube with an equivalent inner diameter of 0.8 mm and a length of 900 mm (0.9 meters) can be used.

[0049] c. Same refrigerant: Matched with a C-*RP359LXXXX model compressor, with a frequency of 50Hz; displacement: 35.9cc, condenser refrigerant outlet temperature: 32.2 degrees Celsius, and theoretical discharge temperature: 95.3 degrees Celsius; when the actual discharge temperature is set to 80 degrees Celsius, the enthalpy difference 1 per compressor cycle is 131; the enthalpy difference 2 between theoretical discharge and actual discharge is 23KJ / Kg; the heat gained by liquid injection cooling in 1 second is 245W; the theoretical injection mass is 1.87g / s; the evaporation-condensation pressure difference MPa is 1.4.

[0050]

[0051] A liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 1100 mm (1.1 meters) can be used.

[0052] The compressor (model C-*RH463LXXXX) is matched with a frequency of 50Hz and a displacement of 46.3cc. The condenser refrigerant outlet temperature is 32.2 degrees Celsius, and its theoretical discharge temperature is 95.3 degrees Celsius. When the actual discharge temperature is set to 80 degrees Celsius, the enthalpy difference (I) of the compressor cycle is 131 kJ / kg; the enthalpy difference (II) between the theoretical discharge and actual discharge is 23 kJ / kg; the heat gained by liquid injection cooling in 1 second is 316 W; the theoretical injection mass is 2.41 g / s; and the evaporation-condensation pressure difference (MPa) is 1.4.

[0053]

[0054] A liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 800 mm (0.8 meters) can be used.

[0055] Example 4: In the compressor with automatic liquid injection cooling via capillary pressure differential described in Example 1 or 2, when R455A is used as the refrigerant, the optimal range for α is 0.7-2.0. The optimal value is 1.45-1.55. To illustrate with a specific example: It is matched with a C-*RVN153LXX model compressor with a frequency of 80Hz and a displacement of 32cc. The condenser refrigerant outlet temperature is 32.2℃, and its theoretical discharge temperature is 110.35℃. When the actual discharge temperature is set to 80℃, the enthalpy difference 1 of the compressor cycle is 142℃; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 30.9℃; the heat obtained by the 32cc 80Hz 1S liquid injection cooling is 1000W; the theoretical injection mass is 7.04g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0056]

[0057] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 600 mm (0.6 meters) can be used.

[0058] BThe same refrigerant: It is matched with a C-*RHN83EXX model compressor with a frequency of 50HZ; a displacement of 16.2cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 110.35 degrees Celsius. When the actual discharge temperature is set to 80 degrees Celsius, the enthalpy difference 1 of one cycle of the compressor is 142KJ / Kg; the enthalpy difference 2 between theoretical discharge and actual discharge is 30.9KJ / Kg; the heat obtained by liquid injection cooling in 1 second is 303W; the theoretical injection mass is 2.13g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0059]

[0060] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 0.8 mm and a length of 600 mm (0.6 meters) can be used.

[0061] c. Same refrigerant: It is matched with a C-*RP359LXXXX model compressor with a frequency of 50Hz; a displacement of 35.9cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 110.35 degrees Celsius. When the actual discharge temperature is set to 80 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 142; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 30.9; the heat gained by liquid injection cooling in 1 second is 530W; the theoretical injection mass is 3.73g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0062]

[0063] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.20 mm and a length of 900 mm (0.9 meters) can be used.

[0064] The compressor (model C-*RH463LXXXX) is matched with a frequency of 50Hz and a displacement of 46.3cc. The condenser refrigerant outlet temperature is 32.2 degrees Celsius, and its theoretical discharge temperature is 110.35 degrees Celsius. When the actual discharge temperature is set to 80 degrees Celsius, the enthalpy difference (I) of the compressor cycle is 142; the enthalpy difference (II) between the theoretical discharge and the actual discharge is 30.9; the heat gained by liquid injection cooling in 1 second is 683W; the theoretical injection mass is 4.81g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0065]

[0066] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.42 mm and a length of 1100 mm (1 meter) can be used.

[0067] Example 5: In the compressor with automatic liquid injection cooling via capillary pressure difference described in Example 1 or 2, when R448A is used as the refrigerant, the optimal range for α is 1.8-3.0. The optimal value is 2.1-2.4.

[0068] To illustrate with a specific example: It is matched with a C-*RVN153LXX model compressor with a frequency of 80Hz and a displacement of 32cc. The condenser refrigerant outlet temperature is 32.2℃, and its theoretical discharge temperature is 117.1℃. When the actual discharge temperature is set to 86℃, the enthalpy difference 1 of the compressor cycle is 152.4℃; the enthalpy difference 2 between theoretical discharge and actual discharge is 42℃; the heat obtained by the 32cc 80Hz 1S liquid injection cooling is 975W; the theoretical injection mass is 6.4g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0069]

[0070] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 400 mm (0.4 meters) can be used.

[0071] BThe same refrigerant: It is matched with a C-*RHN83EXX model compressor with a frequency of 50HZ; a displacement of 14.0cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 117.1 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of one cycle of the compressor is 152.4 KJ / Kg; the enthalpy difference 2 between theoretical discharge and actual discharge is 46 KJ / Kg; the heat gained by liquid injection cooling in 1 second is 292W; the theoretical injection mass is 1.91g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0072]

[0073] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1 mm and a length of 900 mm (0.9 meters) can be used.

[0074] c. Same refrigerant: It is matched with a C-*RP359LXXXX model compressor with a frequency of 50Hz; a displacement of 35.9cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 117.1 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 152.4; the enthalpy difference 2 between theoretical discharge and actual discharge is 38; the heat gained by liquid injection cooling in 1 second is 618.7W; the theoretical injection mass is 4.06g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0075]

[0076] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.20 mm and a length of 600 mm (0.6 meters) can be used.

[0077] The compressor (model C-*RH463LXXXX) is matched with a frequency of 50Hz and a displacement of 46.3cc. The condenser refrigerant outlet temperature is 32.2 degrees Celsius, and its theoretical discharge temperature is 117.1 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 152.4; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 38; the heat gained by liquid injection cooling in 1 second is 798W; the theoretical injection mass is 5.23g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0078]

[0079] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.42 mm and a length of 700 mm (0.7 meters) can be used.

[0080] Example 6: In the compressor with automatic liquid injection cooling via capillary pressure difference described in Example 1 or 2, when the refrigerant is R449A, the optimal range of a in this combination is 1.8-3.0.

[0081] To illustrate with a specific example: It is matched with a C-*RVN153LXX model compressor with a frequency of 80Hz and a displacement of 32cc. The condenser refrigerant outlet temperature is 32.2℃, and its theoretical discharge temperature is 115.9℃. When the actual discharge temperature is set to 86℃, the enthalpy difference 1 of the compressor cycle is 150.7℃; the enthalpy difference 2 between theoretical discharge and actual discharge is 41℃; the heat obtained by the 32cc 80Hz 1S liquid injection cooling is 937W; the theoretical injection mass is 6.21g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0082]

[0083] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 400 mm (0.4 meters) can be used.

[0084] BThe same refrigerant: It is matched with a C-*RHN83EXX model compressor with a frequency of 50HZ; a displacement of 14.0cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 115.9 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of one cycle of the compressor is 150.7KJ / Kg; the enthalpy difference 2 between theoretical discharge and actual discharge is 43KJ / Kg; the heat obtained by liquid injection cooling in 1 second is 273W; the theoretical injection mass is 1.81g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0085]

[0086] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1 mm and a length of 900 mm (0.9 meters) can be used.

[0087] c. Same refrigerant: It is matched with a C-*RP359LXXXX model compressor with a frequency of 50Hz; a displacement of 35.9cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 115.9 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 150.7; the enthalpy difference 2 between theoretical discharge and actual discharge is 36; the heat gained by liquid injection cooling in 1 second is 586W; the theoretical injection mass is 3.89g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0088]

[0089] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.20 mm and a length of 600 mm (0.6 meters) can be used.

[0090] The compressor (model C-*RH463LXXXX) is matched with a frequency of 50Hz and a displacement of 46.3cc. The condenser refrigerant outlet temperature is 32.2 degrees Celsius, and its theoretical discharge temperature is 115.9 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 150.7; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 36; the heat gained by liquid injection cooling in 1 second is 756W; the theoretical injection mass is 5.01g / s; and the evaporation-condensation pressure difference is 2.3Mpa.

[0091]

[0092] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.42 mm and a length of 700 mm (0.7 meters) can be used.

[0093] Example 7: In the compressor automatically cooled by capillary pressure differential as described in Example 1 or 2, when the refrigerant is R454C, the optimal range of a in this combination is 1.2-1.6.

[0094] To illustrate with a specific example: It is matched with a C-*RVN153LXX model compressor with a frequency of 80Hz and a displacement of 32cc. The condenser refrigerant outlet temperature is 32.2℃, and its theoretical discharge temperature is 108.1℃. When the actual discharge temperature is set to 86℃, the enthalpy difference 1 of the compressor cycle is 141; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 30; the heat obtained by the 32cc 80Hz 1S liquid injection cooling is 679W; the theoretical injection mass is 4.81g / s; and the evaporation-condensation pressure difference is 2.15Mpa.

[0095]

[0096]

[0097] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 700 mm (0.7 meters) can be used.

[0098] BThe same refrigerant: It is matched with a C-*RHN83EXX model compressor with a frequency of 50HZ; a displacement of 14.0cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 108.1 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of one cycle of the compressor is 141KJ / Kg; the enthalpy difference 2 between theoretical discharge and actual discharge is 32KJ / Kg; the heat gained by liquid injection cooling in 1 second is 223W; the theoretical injection mass is 1.58g / s; and the evaporation-condensation pressure difference is 2.15Mpa.

[0099]

[0100] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1 mm and a length of 900 mm (0.9 meters) can be used.

[0101] c. Same refrigerant: It is matched with a C-*RP359LXXXX model compressor with a frequency of 50Hz; a displacement of 35.9cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 108.1 degrees Celsius. When the discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 141; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 28; the heat gained by liquid injection cooling in 1 second is 444W; the theoretical injection mass is 3.15g / s; and the evaporation-condensation pressure difference is 2.15Mpa.

[0102]

[0103]

[0104] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.420 mm and a length of 1000 mm (1 meter) can be used.

[0105] The compressor (model C-*RH463LXXXX) is matched with a frequency of 50Hz and a displacement of 46.3cc. The condenser refrigerant outlet temperature is 32.2 degrees Celsius, and its theoretical discharge temperature is 108.1 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference (I) of the compressor cycle is 141; the enthalpy difference (II) between the theoretical discharge and the actual discharge is 28; the heat gained by liquid injection cooling in 1 second is 573W; the theoretical injection mass is 4.06g / s; and the evaporation-condensation pressure difference is 2.15Mpa.

[0106]

[0107] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.42 mm and a length of 800 mm (0.8 meters) can be used.

[0108] Example 8 In the compressor with automatic liquid injection cooling via capillary pressure difference described in Example 1, when the refrigerant is R290, the optimal range of a in this combination is 0.7-0.9.

[0109] To illustrate with a specific example: It is matched with a C-*RVN153LXX model compressor with a frequency of 80Hz and a displacement of 32cc. The condenser refrigerant outlet temperature is 32.2℃, and its theoretical discharge temperature is 102.9℃. When the actual discharge temperature is set to 86℃, the enthalpy difference 1 of the compressor cycle is 330.7℃; the enthalpy difference 2 between theoretical discharge and actual discharge is 34.2℃; the heat obtained by the 32cc 80Hz 1S liquid injection cooling is 360W; the theoretical injection mass is 1.08g / s; and the evaporation-condensation pressure difference is 1.67Mpa.

[0110]

[0111] For example, if a liquid-cooled capillary tube with an equivalent inner diameter of 1.2 mm and a length of 900 mm (0.9 meters) is used, the calculated value of a according to the formula is 1.2 x 1.2 x 1.2 x 1.67 / (0.9 * 3.2 * (80 / 60)) = 0.75; that is, when a capillary tube of this specification is used, the exhaust temperature reaches a level close to the safe temperature that the motor can withstand.

[0112] BThe same refrigerant: It is matched with a C-*RHN83EXX model compressor with a frequency of 50HZ; a displacement of 14.0cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 102.9 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of one cycle of the compressor is 330.7KJ / Kg; the enthalpy difference 2 between theoretical discharge and actual discharge is 35KJ / Kg; the heat obtained by liquid injection cooling in 1 second is 100W; the theoretical injection mass is 0.3g / s; and the evaporation-condensation pressure difference is 1.67Mpa.

[0113]

[0114] The liquid-cooled capillary tubes with an equivalent inner diameter of 0.8 mm and a length of 600 mm (0.6 meters) are used.

[0115] c. Same refrigerant: It is matched with a C-*RP359LXXXX model compressor with a frequency of 50Hz; a displacement of 35.9cc; a condenser refrigerant outlet temperature of 32.2 degrees Celsius; and a theoretical discharge temperature of 102.9 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference 1 of the compressor cycle is 330.7; the enthalpy difference 2 between the theoretical discharge and the actual discharge is 35; the heat gained by liquid injection cooling in 1 second is 256W; the theoretical injection mass is 0.775g / s; and the evaporation-condensation pressure difference is 1.67Mpa.

[0116]

[0117] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.20 mm and a length of 800 mm (0.8 meters) can be used.

[0118] The compressor (model C-*RH463LXXXX) is matched with a frequency of 50Hz and a displacement of 46.3cc. The condenser refrigerant outlet temperature is 32.2 degrees Celsius, and its theoretical discharge temperature is 102.9 degrees Celsius. When the actual discharge temperature is set to 86 degrees Celsius, the enthalpy difference (I) of the compressor cycle is 330.7; the enthalpy difference (II) between the theoretical discharge and the actual discharge is 35; the heat gained by liquid injection cooling in 1 second is 330W; the theoretical injection mass is 1g / s; and the evaporation-condensation pressure difference is 1.67Mpa.

[0119]

[0120] For example, a liquid-cooled capillary tube with an equivalent inner diameter of 1.42 mm and a length of 1000 mm (1 meter) can be used.

Claims

1. A compressor that automatically injects liquid for cooling via capillary pressure differential, comprising: The compressor body is characterized by: a differential pressure liquid injector cooler inserted into and fixed to the compressor body; the outlet pipe of the condenser containing refrigerant connected to the differential pressure liquid injector cooler, such that the condenser outlet pipe is directly connected to the cylinder compression chamber of the compressor via the differential pressure liquid injector cooler; the capillary tube of the differential pressure liquid injector cooler delivers a fixed amount of refrigerant to the cylinder compression chamber under the action of differential pressure; given a determined condensation temperature corresponding to the refrigerant type, a selected compressor with confirmed displacement and compressor frequency, the relationship between the inner diameter and length of the capillary tube is determined by 'a', where 'a' ranges from 0.2 to 7. In the above formula, d represents the equivalent diameter of the capillary tube, in millimeters; L represents the length of the capillary tube, in meters; ΔP represents the pressure difference between the condensing saturation pressure and the evaporating saturation pressure when the condensing temperature is 54.4℃ and the evaporating temperature is -23.3℃. This parameter is determined according to different types of refrigerants, in MPa; b represents the compressor displacement / 10, in milliliters; f represents the compressor frequency, for variable frequency compressors it refers to 80Hz, in Hertz.

2. The compressor with automatic liquid injection cooling via capillary pressure difference as described in claim 1, characterized in that: The compressor body has an inlet hole for installing a differential pressure injection cooler. The injection device of the differential pressure injection cooler is connected to the outlet of a capillary tube, and the inlet of the capillary tube is connected to the inlet component of the differential pressure injection cooler.

3. The compressor with automatic liquid injection cooling via capillary pressure difference as described in claim 2, characterized in that: When the refrigerant is R410A, the optimal range of a is 1.3-2.0; when the refrigerant is R513A, the optimal range of a is 0.3-1.0; when the refrigerant is R449A, the optimal range of a has two parallel groups: the first group is 0.8-1.6 and the second group is 1.8-3.0; when the refrigerant is R455A, the optimal range of a is 0.7-2.0; or when the refrigerant is R448A, the optimal range of a is 1.8-3.0; or when the refrigerant is R290, the optimal range of a is 0.7-0.9; or when the refrigerant is R454C, the optimal range of a is 1.2-1.

6.

4. A method for cooling a compressor according to any one of claims 1-3, characterized in that: A differential pressure injection cooler is installed on the compressor cylinder block. This cooler is connected to the condenser outlet pipe containing refrigerant. The capillary tube of the cooler delivers the refrigerant to the cylinder compression chamber under the influence of the differential pressure, thus cooling the compression space within the compressor. The differential pressure depends on parameter 'a', which is related to the capillary tube inner diameter and length, condensing temperature, compressor displacement, and compressor frequency. The range of 'a' is 0.2–7. In the above formula, d represents the equivalent diameter of the capillary tube, in millimeters; L represents the length of the capillary tube, in meters; ΔP represents the pressure difference between the condensing saturation pressure and the evaporating saturation pressure when the condensing temperature is 54.4℃ and the evaporating temperature is -23.3℃. This parameter is determined according to different types of refrigerants, in MPa; b represents the compressor displacement / 10, in milliliters; f represents the compressor frequency, for variable frequency compressors it refers to 80Hz, in Hertz.

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