CN106052222B - A kind of oil cooled large and medium-sized double throttle chilled water unit of water-cooled - Google Patents

Abstract

The invention relates to a large and medium-sized chiller, in particular to a water-cooled oil-cooled large and medium-sized double-throttling chiller. The refrigerant outlet port of the evaporator is connected to the refrigerant inlet port of the compressor, the refrigerant outlet port of the compressor is connected to the refrigerant inlet port of the oil separator, and the refrigerant outlet port of the oil separator is connected to the refrigerant inlet port of the condenser The refrigerant outlet port of the condenser is connected to the refrigerant inlet port of the double throttling mechanism, and the refrigerant outlet port of the double throttling mechanism is connected to the refrigerant inlet port of the evaporator; the lubricating oil outlet port of the oil separator is connected to the oil The lubricating oil inlet of the cooler is connected, the lubricating oil outlet of the oil cooler is connected to the lubricating oil inlet of the compressor, the cooling water outlet of the cooling tower is connected to the cooling water inlet of the condenser, and the cooling water outlet of the condenser is connected to the cooling tower The water inlet port is connected to the cooling water inlet port of the oil cooler, and the cooling water outlet port of the oil cooler is connected to the cooling water inlet port of the cooling tower.

Description

A water-cooled oil-cooled large and medium-sized double-throttle refrigerating water unit

technical field

The invention relates to a large and medium-sized chiller, in particular to a water-cooled oil-cooled large and medium-sized double-throttling chiller.

Background technique

At present, in general large and medium-sized chillers, the oil cooler and compressor often have the following problems during actual operation:

1. Oil cooler: The lubricating oil separated from the high-temperature and high-pressure oil-air mixture discharged from the compressor has a high temperature and cannot be directly sent into the compressor. It needs to be cooled by the oil cooler to the temperature and viscosity required by the compressor. continue to use. However, at present, the oil coolers in many large and medium-sized chillers have poor cooling effect, which leads to partial cracking of lubricating oil and poor lubricating performance. Especially for the screw chiller, due to its special structure, no matter what kind of refrigerant is used, the problem of high exhaust temperature and oil temperature is common, so there are special requirements for oil cooling. At present, most of the chillers equipped with oil coolers use part of the refrigerant in the refrigeration system itself to cool the lubricating oil, which includes two forms, one is that the oil cooler is separated from the compressor, and the cooled lubricating oil returns to the Compressor; in one form an oil cooler is built into the compressor, where the injected refrigerant both cools the lubricating oil and lowers the cylinder temperature. However, because the above two oil cooling systems utilize part of the refrigerant in the refrigeration cycle, it is easy to cause the problem of poor refrigeration conditions, which is more obvious when the refrigeration load decreases.

2. Compressor: When the refrigeration load of the chiller decreases, the refrigerant flow rate decreases passively, but the content of lubricating oil does not change much, which leads to an increase in the available energy loss of the system and heat transfer conditions of the heat exchanger (especially the evaporator) deterioration. However, the volume displacement of the compressor does not change much, and the input power and exhaust temperature do not change much with the cooling load attenuation, which cannot save energy significantly.

Contents of the invention

The purpose of the present invention is to provide a water-cooled oil-cooled large and medium-sized double-throttle chilled water unit to solve the problem of high compressor exhaust temperature and the use of the refrigerant in the refrigeration cycle itself to cool the existing large and medium-sized chilled water units during operation. The problem of poor cooling effect of the unit caused by lubricating oil. In addition, the present invention solves the problem of improving the cooling energy efficiency of the chiller when the load is attenuated and reducing the discharge temperature and power consumption of the compressor by setting the spiral bypass pipe connected in parallel with the conventional throttling device.

To achieve the above object, the present invention adopts the following technical solutions: a water-cooled oil-cooled large and medium-sized double-throttle chilled water unit, including a refrigerant system, an oil separator and an oil cooler;

The refrigerant system includes an evaporator, a compressor, a condenser, a spiral bypass pipe and a throttling device;

Refrigerating medium side: the spiral bypass pipe and throttling device are arranged in parallel to form a double throttling mechanism, the refrigerant outlet end of the evaporator is connected to the refrigerant inlet end of the compressor through a pipeline, The refrigerant outlet end of the compressor is connected to the refrigerant inlet end of the oil separator through a pipeline 4, and the refrigerant outlet end of the oil separator is connected to the refrigerant inlet end of the condenser through a pipe. The refrigerant outlet port of the condenser is connected to the refrigerant inlet port of the double throttling mechanism through the pipeline six, and the refrigerant outlet port of the double throttling mechanism is connected to the refrigerant refrigerant outlet port of the evaporator. The oil inlet end is connected through pipeline seven; the lubricating oil outlet end of the oil separator is connected with the lubricating oil inlet end of the oil cooler through pipeline three, and the lubricating oil outlet end of the oil cooler is connected with the lubricating oil inlet end of the compressor The end is connected through the second pipeline;

Cooling water side: the cooling water outlet of the cooling tower is connected to the cooling water inlet of the condenser through pipeline eight, and the cooling water outlet of the condenser is divided into two paths, one of which passes through pipeline nine and the cooling water of the cooling tower The inlet end is connected, and the other is connected to the cooling water inlet of the oil cooler through pipeline eleven, and the cooling water outlet of the oil cooler is connected to the cooling water inlet of the cooling tower through pipeline ten.

Compared with prior art, the beneficial effect of the present invention is:

1. Use a water-cooled oil cooler (cooling the oil cooler with cooling water) to cool down the lubricating oil. The heat transfer temperature difference can reach 20°C and above. The cooling effect is good, and it does not affect the circulation of the refrigerant system. Condensed water is economical and environmentally friendly as a cooling medium. In addition, the oil cooler adopts a casing cooler, which has small flow resistance of the refrigerant and good cooling effect.

2. A spiral bypass pipe connected in parallel with the throttling device is added to solve the problem that the compressor outlet temperature of the compressor is higher than that of conventional large and medium-sized chillers, and the discharge temperature can be reduced by 5~20°C. The compression ratio of the compressor is reduced to a certain extent, so that the power consumption of the compressor is reduced by 5%~10%, and the cooling energy efficiency is improved to a certain extent, so that the EER (energy efficiency ratio) value of the compressor after load reduction is higher than that of the conventional system. The operating EER value is increased by 3%~8%.

Description of drawings

Fig. 1 is a structural schematic diagram of a water-cooled oil-cooled large and medium-sized double-throttling chilled water unit of the present invention.

Detailed ways

The technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, not all of them. Based on the present invention All other embodiments obtained by persons of ordinary skill in the art without creative efforts, all belong to the scope of protection of the present invention.

Embodiment 1: As shown in Figure 1, the present invention discloses a water-cooled oil-cooled large and medium-sized double-throttle chilled water unit, including a refrigerant system, an oil separator 3 and an oil cooler 4;

The refrigerant system includes an evaporator 1, a compressor 2, a condenser 5, a spiral bypass pipe 6 and a throttling device 7;

Refrigerating medium side: the spiral bypass pipe 6 and the throttling device 7 are arranged in parallel to form a double throttling mechanism, the refrigerant outlet end of the evaporator 1 and the refrigerant inlet end of the compressor 2 pass through the tube The refrigerant outlet end of the compressor 2 is connected to the refrigerant inlet end of the oil separator 3 through a pipeline four, and the refrigerant outlet end of the oil separator 3 is connected to the condenser 5 The refrigerant inlet end of the refrigerant is connected through pipeline five, the refrigerant outlet end of the condenser 5 is connected with the refrigerant inlet end of the double throttling mechanism through pipeline six, and the refrigerant of the double throttling mechanism The outlet port of the working medium is connected to the inlet port of the refrigerating medium of the evaporator 1 through a pipeline 7; the outlet port of the lubricating oil of the oil separator 3 is connected to the inlet end of the lubricating oil of the oil cooler 4 through a pipeline 3, and the oil cooler The lubricating oil outlet port of 4 is connected with the lubricating oil inlet port of compressor 2 through pipeline two;

Cooling water side: the cooling water outlet end of the cooling tower 8 is connected to the cooling water inlet end of the condenser 5 through a pipeline eight, and the cooling water outlet end of the condenser 5 is divided into two paths, and one path passes through a pipeline nine and the cooling tower 8 is connected to the cooling water inlet end, and the other is connected to the cooling water inlet end of oil cooler 4 through pipeline eleven, and the cooling water outlet end of oil cooler 4 is connected to the cooling water inlet end of cooling tower 8 through pipeline ten .

Specific embodiment two: As shown in Figure 1, the compressor 2 of the present invention is especially suitable for screw compressors, which can significantly reduce the compressor discharge temperature and oil temperature, and the cooling EER (that is, energy efficiency) when the compressor is deloaded Compared with conventional units, it is 3%~8% higher.

Embodiment 3: As shown in FIG. 1 , the oil cooler 4 of the present invention is a casing cooler, and its refrigerant flow resistance is smaller than other types of heat exchangers, and the heat exchange effect is better. The length of the oil cooler 4 is 1m~1.5m.

Embodiment 4: As shown in Figure 1, the material of the spiral bypass pipe 6 according to the present invention is a copper pipe, the inner diameter of the spiral bypass pipe 6 is 8 mm, and the length of the spiral bypass pipe 6 is 900 mm to 1600 mm. mm, the relevant shape parameters can be comprehensively determined according to the specific operation requirements, and the refrigerant outlet end of the spiral bypass pipe 6 is connected to the refrigerant inlet end of the evaporator 1 through the pipeline seven, because if the refrigerant refrigerant of the spiral bypass pipe 6 If the refrigerant outlet port is connected to the refrigerant outlet port of the evaporator 1, the cooling capacity of the system will be lost.

Specific embodiment five: as shown in Figure 1, evaporator 1, compressor 2, oil separator 3, condenser 5 and throttling device 7 of the present invention are all prior art, choose large and medium-sized cold water on the market The type of related equipment routinely used by the unit is sufficient. The throttling device 7 can be an electronic expansion valve, a thermal expansion valve, a throttling orifice, and the like.

Embodiment 6: As shown in FIG. 1 , the height of the end of pipeline 2 close to the oil cooler 4 according to the present invention should be higher than that of the end of pipeline 2 close to the compressor 2 to facilitate oil return.

Embodiment 7: As shown in FIG. 1 , the diameter of pipeline eleven according to the present invention is smaller than that of pipeline nine, because the oil cooler 4 needs little cooling water.

working principle:

Refrigeration medium side: The refrigeration medium (that is, the mixture of refrigerant and lubricating oil) is vaporized and absorbed by the evaporator 1 and becomes superheated steam, which enters the compressor 2 for compression (the temperature exceeds the ambient temperature), and then the compressed refrigeration The working fluid enters the oil separator 3 for separation, and most of the lubricating oil separated from the cooling working medium passes through the lubricating oil outlet of the oil separator 3, flows through the oil cooler 4, and returns to the compressor 2 for further use. The separated cooling working medium Steam (containing a small amount of lubricating oil) then enters the condenser 5 to release heat to the environment. In the condenser 5, the refrigerant vapor is cooled to the saturation temperature of the current pressure (the current pressure refers to the condensation pressure, which is slightly lower than the exhaust pressure),

Then continue to cool down to the supercooled liquid state, and then flow to the double throttling mechanism for throttling and cooling (depressurization) to the two-phase state, and then enter the evaporator 1, vaporize and absorb heat, and complete a cycle process.

Since the spiral bypass pipe 6 and the throttling device 7 are connected in parallel, it is obvious that the refrigerant flow resistance of this double throttling mechanism is smaller than that of a single throttling device, thus reducing the subcooling degree before throttling, and improving the condenser 5 and evaporation. The heat transfer state in the device 1 moderately improves the refrigerant circulation flow in the system.

Cooling water side: the cooling water of the cooling tower 8 passes through the condenser 5 and exchanges heat with the refrigerant, and the temperature rises. Secondary heat exchange is performed in the cooling water inlet port of the oil cooler 4, and after the heat exchange, it returns to the cooling tower 8 to be re-cooled, and another part of the cooling water that flows out directly returns to the cooling tower 8 to be re-cooled, and so on.

It will be obvious to a person skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, but that it can be implemented in other configurations without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents are included in the invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only includes an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (4)

1. a kind of oil cooled large and medium-sized double throttle chilled water unit of water-cooled, including cryogen system, oil eliminator（3）And oil Cooler（4）；It is characterized in that：The cryogen system includes evaporator（1）, compressor（2）, condenser（5）, spiral bypass Pipe（6）And throttling set（7）；

Refrigeration working medium side：The spiral bypass pipe（6）And throttling set（7）It is arranged in parallel and constitutes double throttle mechanism, it is described Evaporator（1）Refrigeration working medium outlet end and compressor（2）Refrigeration working medium input end connected by pipeline one, the compression Machine（2）Refrigeration working medium outlet end and oil eliminator（3）Refrigeration working medium input end connected by pipeline four, the described oil separation Device（3）Refrigeration working medium outlet end and condenser（5）Refrigeration working medium input end connected by pipeline five, the condenser （5）Refrigeration working medium outlet end connect by pipeline six with the refrigeration working medium input end of double throttle mechanism, the double throttle machine The refrigeration working medium outlet end of structure and evaporator（1）Refrigeration working medium input end is connected by pipeline seven；Oil eliminator（3）Lubricating oil Outlet end and oil cooler（4）Lubricating oil inlet end connected by pipeline three, the oil cooler（4）Lubricating oil outlet End and compressor（2）Lubricating oil inlet end connected by pipeline two；

Cooling water side：Cooling tower（8）Cooling water outlet end and condenser（5）Cooling water inlet end connected by pipeline eight, Condenser（5）Cooling water outlet end be divided into two-way, pass through pipeline nine and cooling tower all the way（8）Cooling water inlet end connection, Another way passes through pipeline 11 and oil cooler（4）Cooling water inlet end connection, oil cooler（4）Cooling water outlet end with Cooling tower（8）Cooling water inlet end connected by pipeline ten.

2. the oil cooled large and medium-sized double throttle chilled water unit of a kind of water-cooled according to claim 1, it is characterised in that： Pipeline eight, pipeline nine and the pipeline ten is condensate pipe.

3. the oil cooled large and medium-sized double throttle chilled water unit of a kind of water-cooled according to claim 1, it is characterised in that： The spiral bypass pipe（6）Material be copper pipe, spiral bypass pipe（6）Interior diameter be 8mm, spiral bypass pipe（6）Length Degree is the mm of 900 mm ~ 1600.

4. the oil cooled large and medium-sized double throttle chilled water unit of a kind of water-cooled according to claim 1,2 or 3, feature It is：The oil cooler（4）For double-pipe cooler.