WO2005083335A1

WO2005083335A1 - Modular Refrigerating Installation with Overflow Vaporization System

Info

Publication number: WO2005083335A1
Application number: PCT/CN2004/000347
Authority: WO
Inventors: Ningfan Zhao
Original assignee: Guangzhou Panyu Super Link Co. Ltd
Priority date: 2004-02-25
Filing date: 2004-04-14
Publication date: 2005-09-09
Also published as: CN100414222C; CN1661304A

Abstract

A modular refrigerating installation with overflow vaporization system, which has several modular refrigerating units. Each modular refrigerating unit has a refrigerating circle which includes at least a refrigerating compressor (1), an evaporator (5) with a plate type heat exchanger and a condenser (9). The unit also has an overflow ladle (6) which is a vessel with a refrigerant inlet (61), a liquid refrigerant outlet (62) and a gaseous refrigerant outlet (63). The refrigerant inlet (61) of the overflow ladle is connected to the refrigerant outlet (92) of the condenser (9). The liquid refrigerant outlet (62) of the overflow ladle is connected to the refrigerant inlet (51) of the evaporator. The gaseous refrigerant outlet (63) of the overflow ladle and refrigerant outlet (52) of the evaporator are both connected to a inlet (lA) of the compressor (1). The overflow ladle (6) is mounted with a lattice (64) for separating gas and liquid. The refrigerating efflciency of the installation according to the present invention is higher and is adapted for combined type modular refrigerating installation and integral type refrigerating installation.

Description

Modular refrigeration unit with overflow evaporation system

Technical field

The invention relates to a refrigeration device, in particular to a modular refrigeration device with an overflow evaporation system. Background technique

Modular combined refrigeration units have been widely used in the design and application of chillers for air conditioning systems. This modular combined chiller is composed of multiple standard refrigeration module units according to the needs of the building installation load. It can increase or decrease the installed capacity of the system at any time, so it is very flexible to use. In addition, since each refrigeration module unit is a complete refrigeration system, under the control of the main controller, the number of module unit operations is increased or decreased according to the needs of the system load. Therefore, the refrigeration output of the unit can not only maintain the system demand The high degree of consistency also enables the unit to have peak operating efficiency under low-load operating conditions, which will not reduce operating efficiency due to load reduction, and can reduce unit operating costs. In addition, the modular combined chiller has a high degree of reliability. Even if some module units fail, the other parts of the unit can continue to operate, and the faulty part can be repaired and maintained while the unit is running. Therefore, modular combined refrigeration units have many advantages not found in other systems. One type of various modular combination refrigeration devices is a plate heat exchanger installed as an evaporator in each refrigeration module unit. The plate heat exchanger itself has the advantages of compact structure and high heat exchange coefficient. However, when it is used as an evaporator, the refrigerant expands through throttling and becomes a two-phase mixture of gas and liquid. After the mixed refrigerant enters the plate heat exchanger, it is not distributed to each plate flow channel in a uniform proportion. For a flow channel with a large gas content, the heat transfer coefficient will be relatively small, A liquid channel with more liquid content may not completely evaporate, and the refrigerant entering in a gas state not only contributes very little to the cooling capacity, but also occupies a very small amount.

¾ Form feed (rule ²⁶ ) The large heat transfer area, because the thermal conductivity of the gas is much smaller than that of the liquid, the air mass or bubbles formed by the gas part of the mixture will affect the rapid heat transfer, making the plate heat exchanger unable to achieve the best heat transfer efficiency. Content of the invention

The object of the present invention is to provide a modular refrigeration device with an overflow evaporation system, which can further improve the heat exchange efficiency of a plate heat exchanger, so that the refrigeration device has a higher refrigeration efficiency. The object of the present invention is achieved according to the following technical scheme.

The invention is a modular combined refrigeration device with an overflow evaporation system, which is composed of a plurality of modular refrigeration units, and each of said modular refrigeration units has one or more refrigeration refrigeration units, evaporators, and condensers. And a refrigeration circuit of a throttling and expansion device, the evaporator is a plate heat exchanger, and has an evaporator refrigerant inlet and an evaporator refrigerant outlet, an evaporator frozen water inlet, and an evaporator frozen water outlet; its characteristics are:

It also includes an overflow bucket. The overflow bucket is a container. The throttled and expanded refrigerant first undergoes gas-liquid separation through the overflow bucket, the liquid part of the refrigerant enters the evaporator, and the gas part of the refrigerant is The gas from the evaporator returns to the compressor.

The overflow bucket has an overflow bucket refrigerant inlet, an overflow bucket liquid refrigerant outlet, and an overflow bucket gas refrigerant outlet; the overflow bucket refrigerant inlet and the throttling and expansion device, and The refrigerant outlet of the condenser is connected; the liquid refrigerant outlet of the overflow bucket is connected with the refrigerant inlet of the evaporator; the gas refrigerant outlet and the evaporator refrigerant outlet of the overflow bucket are both connected. It is connected with the suction port of the compressor; a gas-liquid separation net is arranged in the overflow barrel. After throttling and expanding, the refrigerant first passes through the refrigerant inlet of the overflow barrel for gas-liquid separation; the liquid portion of the refrigerant enters the plate evaporator refrigerant inlet through the liquid refrigerant outlet, and the gas portion of the refrigerant flows from the overflow barrel. The refrigerant outlet returns to the compressor. The invention also includes a regenerator, the regenerator is a container, the fluid entering from one side of the regenerator is a liquid refrigerant from a condenser, and the fluid entering from the other side is from an evaporator And the gas refrigerant in the overflow bucket, the two fluids are heat-exchanged in the regenerator. The regenerator has a regenerator air inlet, a regenerator air outlet and a heat exchange tube located in the container, and the outlet of the condenser refrigerant passes through the heat exchange tube and the throttling expansion device and the overflow The flow bucket refrigerant inlet is connected; the overflow bucket gas refrigerant outlet and the evaporator refrigerant outlet are both connected to the compressor inlet and the compressor outlet through the regenerator air inlet and the regenerator air outlet. Connected. The liquid refrigerant enters the regenerator side from the condenser refrigerant outlet; the gas refrigerant from the evaporator and the overflow barrel enters from the regenerator inlet side. An oil separator is installed between the suction port of the compressor and the condenser. A throttling expansion valve for controlling the liquid level of the refrigerant in the overflow barrel is installed inside or outside the overflow barrel, which is a float type or thermoelectric type or other type of expansion valve. A condensing pressure controller is installed outside the overflow bucket to control the flow of the medium into the condenser. The condensing pressure controller is connected to the electrical system. It senses the size of the condensing pressure and determines the opening degree of the flow regulating valve according to the size of the condensing pressure. When the condensing pressure is too high, the valve opening degree is increased, and vice versa. Opening of the valve. The modular refrigeration unit further includes a chilled water inlet and outlet header, a chilled water inlet and outlet header, and a chilled water inlet and a chilled water outlet of each evaporator are respectively connected with the chilled water. A water inlet header and a chilled water outlet header are connected in parallel; a cooling water inlet and a cooling water outlet in the condenser are connected in parallel with the cooling water inlet header and the cooling water outlet header, respectively. The modular refrigeration device further includes a chilled water inlet header and a chilled water outlet header. The chilled water inlet and chilled water outlet of each evaporator are respectively connected to the chilled water inlet and chilled water. Water outlet headers are connected in parallel; the condenser is an air-cooled condenser. The invention has an overflow evaporation system in a refrigeration module unit, and an overflow barrel is added to the plate heat exchanger in the refrigeration circuit. The overflow barrel is used for storing refrigerant and performing gas-liquid separation. The throttling and expanding refrigerant is first subjected to gas-liquid separation through an overflow barrel. The liquid portion of the refrigerant enters the evaporator, and the gas portion of the refrigerant returns to the compressor together with the gas discharged from the evaporator. In this way, not only the heat exchange efficiency of the evaporator will be greatly improved, but also the area of the plate heat exchanger required can be reduced. Since the refrigerant entering the evaporator is a pure liquid, it can be evenly distributed between the plate flow channels, and the part of the expanded gas will not enter the evaporator, which prevents this part of the gas from occupying the heat exchange surface and making the heat transfer area It is more effectively used, so the heat exchange temperature difference is reduced, and the heat exchange efficiency of the evaporator is improved. Increasing the heat exchange efficiency of the evaporator can increase the evaporation temperature for the thermal cycle of the refrigeration system, which brings the advantages of increasing the refrigeration capacity of the unit and improving the efficiency of the refrigeration cycle of the unit. In addition, a regenerator is installed between the overflow bucket and the compressor suction port. One side of this regenerator is liquid refrigerant from the condenser, and the other side is from the evaporator and the overflow bucket. Gas refrigerant, the two fluids exchange heat in this regenerator, so that the liquid refrigerant is supercooled, while the gas refrigerant is beneficially overheated, and the remaining cooling capacity in the gas part is recovered, which is beneficial to the improvement of refrigeration efficiency . An oil separator is installed between the discharge port of the compressor and the condenser. The exhaust of the refrigeration compressor first enters the oil separator, which separates the lubricating oil entrained in the exhaust and returns it to the compressor, while the gas refrigerant enters the condenser from the oil separator. The expansion and throttling device is used to control the refrigerant level. The level of the overflow tank is maintained to maintain the necessary level in the evaporator. When the evaporation load is reduced and the liquid level in the evaporator is raised while the liquid level in the overflow bucket is increased, the throttle expansion device is used to reduce the valve opening to reduce the liquid supply. Conversely, when the evaporation load is increased, the throttle expansion device increases the valve angle and increases the liquid supply. The condensing pressure controller is used to control the flow of cooling medium, such as water or air, into the condenser. When the condensing pressure is too low, the cooling medium supply is reduced and the condensing pressure rises. When the condensation pressure is too high, the supply of cooling medium is increased. The role of the condensing pressure controller is to maintain an appropriate condensing pressure to prevent the evaporation temperature of the refrigerant in the overflow bucket from being too low when the condensing pressure is too low. Use the outlet temperature of the refrigerant to adjust the compressor output capacity. The output capacity of the compressor is adjusted according to the outlet temperature of the evaporator refrigerant medium. When the outlet temperature decreases, the working output of the compressor is reduced, and when the outlet temperature increases, the working output of the compressor is increased. In summary, the present invention uses an overflow evaporation system and a regenerator to improve the refrigeration cycle efficiency of the unit; an oil separator, an expansion throttling device, and a condensing pressure controller are used to regulate the refrigerant, condensate, and chilled water. Balance of temperature and flow to save energy; so that the refrigeration unit has higher cooling efficiency. The invention is applicable to a combined modular refrigeration device and an integrated refrigeration device. BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1 and 2 are schematic diagrams of the working flow of a modular refrigeration device with an overflow evaporation system according to the present invention, and Figure 3 is a schematic structural diagram of a modular refrigeration unit with a overflow refrigeration system and a modular refrigeration device according to the present invention.

FIG. 4 is a schematic structural diagram of a modular refrigeration unit modular refrigeration unit with an overflow evaporation system according to the present invention (the condenser is air-cooled). Code in the picture

Compressor 1A Compressor suction port 1B Compressor discharge port regenerator 21 Reheater air inlet 22 Reheater air outlet Reheater heat exchanger tube Frozen water inlet header 4 Frozen water outlet header evaporator 51 Evaporator refrigerant inlet 52 Evaporator refrigerant outlet 3 Evaporator chilled water inlet 54 Evaporator chilled water outlet overflow bucket 61 overflow bucket refrigerant inlet 62 overflow bucket liquid refrigerant outlet

63 overflow bucket gas refrigerant outlet 64 liquid separation network refrigerant drying filter 8 throttling expansion device condenser 91 condenser refrigerant inlet 92 condenser refrigerant outlet 3 condenser cooling water inlet 94 condenser cooling water outlet cooling Water inlet header 11 Cooling water outlet header 12 Oil separator condenser Cooling water flow regulating valve 14 Evaporator Frozen water flow regulating valve Condensing pressure controller Examples

This embodiment is used to explain the present invention.

The modular combined refrigeration unit with overflow evaporation system consists of multiple modular refrigeration units. Figure 1 is a schematic diagram of a modular refrigeration unit with an overflow evaporation system. Each modular unit has a refrigeration circuit including a refrigeration compressor 1, an evaporator 5, a condenser 9, and a throttling expansion device 8. The evaporator 5 is a plate heat exchanger, and has an evaporator refrigerant inlet 51 and an evaporator refrigerant outlet 52, an evaporator frozen water inlet 53 and an evaporator frozen water outlet 54.

It also includes an overflow bucket 6, which is a container. The throttled and expanded refrigerant first undergoes gas-liquid separation through the overflow bucket 6, the liquid part of the refrigerant enters the evaporator 5, and the gas part of the The refrigerant returns to the compressor 1 together with the gas discharged from the evaporator 5.

The specific structure of the overflow bucket 6 is: having an overflow bucket refrigerant inlet 61, an overflow bucket liquid refrigerant outlet 62, and an overflow bucket gas refrigerant outlet 63; the overflow bucket refrigerant inlet 61 is The throttling and expansion device 8, the filter 7 is connected to the refrigerant outlet 92 of the condenser 9; the overflow barrel liquid refrigerant outlet 62 is connected to the evaporator refrigerant inlet 51; the overflow barrel gas refrigerant outlet 63 is connected to the evaporator The refrigerant outlet 52 is connected to the suction port 1A of the compressor 1; a gas-liquid separation network 64 is installed in the overflow bucket 6 to prevent a small amount of liquid droplets entrained in the gas from being brought into the compressor 1 . During operation, the throttled and expanded refrigerant enters the overflow bucket 6 from the overflow bucket refrigerant inlet 61 and performs gas-liquid separation, so that the liquid portion of the refrigerant enters the evaporator 5 through the overflow bucket liquid refrigerant outlet 62, The refrigerant in the gas part is returned to the suction port 1A of the compressor 1 together with the gas discharged from the evaporator 5 through the gas-liquid separation network 64 and the overflow refrigerant gas outlet 63, so that not only the evaporator replacement The thermal efficiency is greatly improved, and the area of the plate heat exchanger required can be reduced. Since the refrigerant entering the evaporator 5 is a pure liquid, it can be evenly distributed between the plate flow channels, and the part of the gas after the expansion is not entered into the evaporator 5, preventing this part of the gas from occupying the heat exchange surface and causing heat transfer. The area is more effectively used, so the heat exchange temperature difference is reduced, the heat exchange efficiency of the evaporator is improved, and the refrigeration cycle efficiency of the unit is improved. The invention also includes a regenerator 2. The regenerator 2 is a container, the fluid entering from one side of the regenerator 2 is a liquid refrigerant from the condenser 9, and the fluid entering from the other side is from the evaporator 5 and the overflow bucket. The gas refrigerant of 6 and the two fluids perform heat exchange in the regenerator 2.

Fig. 2 is an embodiment in which a regenerator 2 is added on the basis of Fig. 1. The regenerator 2 is located between the overflow bucket 6 and the compressor suction port 1A. The regenerator 2 is a container. It has a regenerator air inlet 21, a regenerator air outlet 22 and a heat exchange tube 23. The reheater air inlet 21 is connected to the evaporator refrigerant outlet 52 and the overflow bucket gas refrigerant outlet 63. The regenerator outlet 22 is connected to the suction port 1A of the compressor 1, and the heat exchange tube 23 is located in the container. One end of the heat exchange tube 23 is connected to the refrigerant outlet 92 of the condenser 9, and the other end is connected to the refrigerant drying filter 7. Device 8 is connected. The liquid refrigerant flowing from the heat exchange tube 23 to the refrigerant inlet 61 and the gas refrigerant flowing from the regenerator inlet 21 and the regenerator outlet 22 are heat exchanged in the regenerator 2 The liquid refrigerant is supercooled, while the gas refrigerant is beneficially overheated, and the remaining cooling capacity in the gas portion is recovered, which is beneficial to the improvement of heat exchange efficiency. As shown in FIGS. 1 and 2, an oil separator 12 is installed between the discharge port 1 B of the compressor 1 and the condenser 9. A throttling expansion device 8 for controlling the liquid level of the refrigerant in the overflow barrel is installed outside the overflow barrel 6, and its purpose is to increase the liquid level in the evaporator 5 while reducing the evaporation load, and at the same time to overflow When the liquid level of the bucket 6 rises, the throttle expansion device 8 is reduced to reduce the valve opening degree to reduce the liquid supply amount. Conversely, when the evaporation load increases, the throttle expansion device 8 increases the valve opening degree and increases the liquid supply amount. Float ball throttles can be used, thermoelectric expansion valves, or other expansion and throttle devices can also be used. Condensing pressure is installed on the compressor exhaust line to control the flow of the medium into the condenser 9 力控制 15。 Force controller 15. The condensing pressure controller 15 is also connected to the electrical system. It senses the size of the condensing pressure and determines the opening of the flow regulating pot 13 according to the size of the condensing pressure. When the condensing pressure is too high, the valve opening is increased, and vice versa Reduce the valve opening. The flow control valve 14 installed on the chilled water line of the evaporator 5 is also connected to the electrical system. When the compressor is unloaded or closed when the output load of the unit is reduced, the electrical control system simultaneously instructs the flow adjustment valve 14 to reduce the valve opening, and even Close the valve completely to reduce the flow of chilled water and reduce the operating power of the chilled water delivery pump. When the output load of the compressor increases, the angle of the valve is increased, and the flow of the chilled water is increased. As shown in FIG. 3, when the refrigeration units are combined into a modular refrigeration device, the system further includes a chilled water inlet header 3 and an outlet header 4, a cooling water inlet header 10 and an outlet header 11. The chilled water inlet 53 and the chilled water outlet 54 of each evaporator are connected in parallel with the chilled water inlet header 3 and the chilled water outlet header 4 respectively; the cooling water inlet 93 and the cooling in the condenser 9 The water outlet 94 is connected to the cooling water inlet header 10 and the cooling water outlet header 11 in parallel. These headers of each refrigeration unit module are connected in order to become a common channel for the refrigeration and cooling medium fluids of the refrigeration device. As shown in FIG. 4, the condenser 9 is air-cooled. The modular refrigeration device further includes a chilled water inlet header 3 and an outlet header 4. The chilled water inlets 53 of the evaporators, The chilled water outlet 54 is connected in parallel with the chilled water inlet header 3 and the chilled water outlet header 4 respectively; these headers of each refrigeration unit module are connected in order to become a common channel for the refrigeration medium fluid of the refrigeration device. . The condenser 9 is a finned coil condenser, which is air-cooled, and does not need cooling water inlet and outlet headers.

With the refrigeration device of the present invention, for evaporators of the same size, the evaporation temperature can be increased by 2 to 2.5 ° C, the cooling capacity can be increased by about 9%, and the refrigeration performance coefficient can be increased by about 7%.

Claims

Rights request

1 "modular combined refrigeration unit with overflow evaporation system, which consists of multiple modular refrigeration units, each of which

The module refrigeration units each have one or more refrigeration circuits including a refrigeration compressor (1), an evaporator (5), and a condenser (9). The evaporator (5) is a plate heat exchanger and has an evaporator. The refrigerant inlet (51) and the evaporator refrigerant outlet (52), the evaporator chilled water inlet (53) and the evaporator chilled water outlet (54) are characterized by:

It also includes an overflow bucket (6), where the overflow bucket (6) is a container, and the throttled and expanded refrigerant is first subjected to gas-liquid separation through the overflow bucket (6), and the liquid part of the refrigerant enters the evaporator (5), and the refrigerant in the gas part is returned to the compressor.

2. The modular combined refrigeration device with an overflow evaporation system according to claim 1, characterized in that-the overflow bucket (6) has an overflow bucket refrigerant inlet (61), and an overflow bucket The liquid refrigerant outlet (62) and the overflow barrel gas refrigerant outlet (63); the overflow barrel refrigerant inlet (61) is in communication with the refrigerant outlet (92) of the condenser (9); The overflow refrigerant liquid refrigerant outlet (62) is connected to the evaporator refrigerant inlet (51); the overflow barrel gas refrigerant outlet (63) is connected to the compressor (1) The suction inlet (1A) is connected; a gas-liquid separation net (64) is installed in the overflow bucket (6); the throttled and expanded refrigerant first passes through the refrigerant inlet of the overflow bucket (6) ( 61) performing gas-liquid separation; the liquid part of the refrigerant enters the evaporator refrigerant inlet (51) through the liquid refrigerant outlet (62), and the gas part of the refrigerant returns from the refrigerant outlet (63) to the compressor (1) ) 'S suction port (1A).

3. The modular combined refrigeration device with an overflow evaporation system according to claim 2, further comprising: a regenerator (2), wherein the regenerator (2) is a container, From the regenerator (2) The fluid entering from the side is the liquid refrigerant from the condenser (9), and the fluid entering from the other side is the gas refrigerant from the evaporator (5) and the overflow bucket (6). The fluid is heat-exchanged in the regenerator (2).

4. The modular combined refrigeration device with an overflow evaporation system according to claim 3, wherein:

The container has a regenerator air inlet (21), a regenerator air outlet (22), and a heat exchange tube (23) located in the container. The refrigerant outlet (92) of the condenser (9) passes through The heat exchange tube (23) is connected to the overflow bucket refrigerant inlet (61); the overflow bucket gas refrigerant outlet (63) and the evaporator refrigerant outlet (52) are all passed through the return pipe. The air inlet (21) and the air outlet (22) of the regenerator are connected to the inlet (1A) of the compressor (1); the refrigerant outlet (92) from the reheater (2) ) —Side into the liquid refrigerant; from the side of the gas inlet (21) of the regenerator, into the gas refrigerant from the evaporator (5) and the overflow barrel (6), the two fluids are in the reheating Heat exchanger (2).

The modular combined refrigeration device with an overflow evaporation system according to any one of claims 1 to 4, characterized in that-the discharge port (1 B) of the compressor (1) and the An oil separator (12) is installed between the condenser (9) mentioned above.

6. The modular combined refrigeration device with an overflow evaporation system according to any one of claims 1 to 4, wherein:

It also includes a throttling expansion device (8) for controlling the liquid level of the refrigerant in the overflow barrel, and the throttling expansion device (6) is installed in the overflow barrel (6) or outside the overflow barrel (6) ( 8) . .

7. Modular group with overflow evaporation system according to any one of claims 1 to 4 The combined refrigeration device is characterized in that: a condensing pressure controller (15) for controlling a flow rate of a medium entering the condenser is installed outside the overflow barrel (6).

8. The modular combined refrigeration device with an overflow evaporation system according to any one of claims 1 to 4, wherein the modular refrigeration unit further comprises a chilled water inlet header (3) and The water outlet header (4), the cooling water inlet header (10) and the water outlet header (11), the frozen water inlet (53) and the frozen water outlet (54) of each evaporator are respectively connected with the freezing The water inlet header (3) and the chilled water outlet header (4) are connected in parallel; the cooling water inlet (93) in the condenser (9): the cooling water outlet (94) and the cooling respectively The water inlet header (10) and the cooling water outlet header (11) are connected in parallel.

9. The modular combined refrigeration device with an overflow evaporation system according to any one of claims 1 to 4, wherein:

The modular refrigeration device further includes a chilled water inlet header (3) and a chilled water outlet header (4). The chilled water inlet (53) and chilled water outlet (54) of each evaporator are respectively connected with The chilled water inlet header (3) and the chilled water outlet header (4) are connected in parallel; the condenser (9) is an air-cooled condenser.