Mechanical refrigeration system

Abstract

The utility model discloses a mechanical refrigerating system which comprises a compressor, a condenser, a throttling device and an evaporator which are sequentially communicated, the compressor is provided with a cooling loop, and an inlet of the cooling loop is communicated to a channel between the throttling device and the evaporator through a first flow control valve. In the mechanical refrigerating system, when the mechanical refrigerating system is used and the compressor needs to start to cool, namely, the main path system where the compressor is located already starts to work, and the low-temperature refrigerant already flows out of the outlet of the throttling device, so that the use requirement can be met. The flow control valve is adopted, compared with throttling devices, the cost is low, the number of the throttling devices is reduced, energy consumption can be better reduced, meanwhile, the requirement for cooling time and the requirement for accurate control over cooling power can be met, and the use requirement can be well met. In conclusion, the mechanical refrigeration system can effectively solve the problem that an existing mechanical refrigeration system is high in energy consumption.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning, and more specifically to a mechanical refrigeration system. Background Art

[0002] The existing centrifugal compressor refrigeration system has high power density and high heat generation due to the high speed. The existing technology usually adopts an independent motor cooling circuit, which introduces a separate circuit from the condenser outlet. The circuit has an electronic expansion valve, a motor cooling inlet, a motor cooling outlet, and then returns to the compressor suction end; this increases the complexity of the system, and the throttling loss of the electronic expansion valve is large, which reduces energy efficiency.

[0003] In the process of realizing the utility model, the inventor discovered that there are at least the following problems in the prior art: How to effectively solve the problem of relatively high energy consumption of current mechanical refrigeration systems is an issue that technical personnel in this field urgently need to solve. Utility Model Content

[0004] In view of this, an object of the present invention is to provide a mechanical refrigeration system, which can effectively solve the problem of relatively high energy consumption of current mechanical refrigeration systems.

[0005] In order to achieve the above object, the utility model provides the following technical solutions:

[0006] A mechanical refrigeration system comprises a compressor, a condenser, a throttling device and an evaporator which are connected in sequence. The compressor is provided with a cooling circuit, and the inlet of the cooling circuit is connected to the channel between the throttling device and the evaporator through a first flow control valve.

[0007] In the above-mentioned mechanical refrigeration system, when in use, when the compressor needs to start cooling, that is, the main circuit system where the compressor is located has started working, the outlet of the throttling device has already flowed out low-temperature refrigerant, which can meet the use requirements. The cooling power requirements of the cooling circuit can be adjusted by adjusting the opening degree of the flow control valve to adjust the incoming refrigerant flow, and then adjust the cooling power, so that the cooling needs can be met. The use of a flow control valve is relatively low in cost compared to a throttling device, and reducing the number of throttling devices can better reduce energy consumption, while meeting the cooling time requirements and the cooling power precise control requirements, so as to be able to meet the use requirements well. In summary, the mechanical refrigeration system can effectively solve the problem of relatively high energy consumption of the current mechanical refrigeration system.

[0008] In some technical solutions, a temperature detector for detecting the temperature of the compressor is also included, and the first flow control valve is linked with the temperature detector to adjust the opening degree according to the temperature change.

[0009] In some technical solutions, a booster pump is further included, and the booster pump is used to accelerate the pumping of the fluid on the channel between the throttling device and the evaporator to the cooling circuit.

[0010] In some technical solutions, the boost pump and the first flow control valve are arranged in series.

[0011] In some technical solutions, the boost pump and the first flow control valve are arranged in series, and a one-way valve is connected in series to the first flow control valve.

[0012] In some technical solutions, the outlet of the cooling circuit is connected between the evaporator and the compressor, and is arranged close to the evaporator.

[0013] In some technical schemes, an economizer is also included. The compressor includes a low-stage compression part and a high-stage compression part connected in series through a progressive channel along the fluid flow direction. The first channel of the economizer is connected between the condenser and the throttling device; and one end of the outlet of the second channel of the economizer is connected to the progressive channel.

[0014] In some technical solutions, the inlet of the second channel is connected to the outlet of the boost pump.

[0015] In some technical solutions, the outlet of the boost pump divides the fluid into the cooling circuit and the second channel through a diversion structure, and a switch valve or the first flow control valve is provided between the diversion structure and the cooling circuit.

[0016] In some technical solutions, a second flow control valve is provided between the flow diversion structure and the second channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the structure of a mechanical refrigeration system provided by an embodiment of the utility model;

[0019] Figure 2 A schematic diagram of the structure of a mechanical refrigeration system when booster pumps are connected in parallel according to an embodiment of the utility model;

[0020] Figure 3 A schematic diagram of the structure of a mechanical refrigeration system when booster pumps are connected in series according to an embodiment of the utility model;

[0021] Figure 4 This is a structural schematic diagram of a mechanical refrigeration system when an economizer provided in an embodiment of the utility model is connected to a booster pump.

[0022] The following are marked in the accompanying drawings:

[0023] Compressor 1, condenser 2, throttling device 3, evaporator 4, first flow control valve 5, booster pump 6, economizer 7, second flow control valve 8, cooling circuit 9. DETAILED DESCRIPTION

[0024] The embodiment of the utility model discloses a mechanical refrigeration system, which effectively solves the problem of relatively high energy consumption of the current mechanical refrigeration system.

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] See also Figure 1-Figure 4 , Figure 1 A schematic diagram of the structure of a mechanical refrigeration system provided by an embodiment of the utility model; Figure 2 A schematic diagram of the structure of a mechanical refrigeration system when booster pumps are connected in parallel according to an embodiment of the utility model; Figure 3 A schematic diagram of the structure of a mechanical refrigeration system when booster pumps are connected in series according to an embodiment of the utility model; Figure 4 This is a structural schematic diagram of a mechanical refrigeration system when an economizer provided in an embodiment of the utility model is connected to a booster pump.

[0027] In some instances, a mechanical refrigeration system is provided in this embodiment. Specifically, the mechanical refrigeration system mainly includes a compressor 1, a condenser 2, a throttling device 3, an evaporator 4 and a first flow control valve 5.

[0028] The compressor 1, condenser 2, throttling device 3 and evaporator 4 are connected in sequence, that is, the outlet of evaporator 4 also needs to be connected to the inlet of compressor 1 to form a circulation system, called the main circuit. Heat is released at condenser 2 and heat is absorbed at evaporator 4 to achieve temperature control. The compressor 1 compresses the inhaled gas to form high-temperature and high-pressure superheated steam, which releases heat to the outside after flowing into condenser 2 to form medium-temperature and high-pressure liquid. Through the throttling process of throttling device 3, the liquid becomes medium-temperature and low-pressure liquid. When the outlet of throttling device 3 flows through evaporator 4, the gas pressure drops rapidly and the volume expands rapidly, which absorbs a large amount of heat to achieve temperature transfer.

[0029] The compressor 1 is provided with a cooling circuit 9, which is mainly used to cool the power components on the compressor 1. Generally, the power components on the compressor 1 are the motor parts, and the cooling circuit 9 is used to cool the motor parts. The specific arrangement of the cooling circuit 9 on the compressor 1 can be arranged according to the cooling needs of the compressor 1. An inlet and an outlet are formed on the cooling circuit 9. The main part of the cooling circuit 9 can be wound around the power components, or the cavity where the power components are located can be used to form the above-mentioned cooling circuit 9. The specific arrangement can be made according to the needs.

[0030] A branch is led out from the passage between the throttling device 3 and the evaporator 4 to introduce the low-temperature fluid flowing out of the throttling device 3 into the cooling circuit 9, that is, the inlet of the cooling circuit 9 is connected to the passage between the throttling device 3 and the evaporator 4 to introduce a part of the refrigerant. The outlet of the cooling circuit 9 can be connected between the evaporator 4 and the compressor 1 to return to the main circuit; the outlet of the cooling circuit 9 can also be connected to the inlet of the evaporator 4. On the passage between the throttling device 3 and the evaporator 4, the outlet connection position of the cooling circuit 9 is not only at the downstream position of the inlet connection position of the cooling circuit 9, but also should be separated by a certain distance to avoid interference, such as the former is set close to the inlet of the evaporator 4, and the latter is set close to the outlet of the throttling device 3.

[0031] In some embodiments, the inlet of the cooling circuit 9 is generally connected to the channel between the throttling device 3 and the evaporator 4 through the first flow control valve 5, so as to control the amount of refrigerant introduced through the first flow control valve 5, so as to achieve control of the cooling efficiency of the cooling circuit 9. The first flow control valve 5 refers to a valve that can adjust the flow of fluid. Since gas or gas-liquid mixture flows in the channel between the throttling device 3 and the evaporator 4, the flow control valve should be able to meet the corresponding requirements. As the cooling needs of the compressor 1 increase, the corresponding first flow control valve 5 is expanded. At this time, the throttling device 3 can correspondingly expand the flow rate or remain unchanged. Whether the cooling needs of the compressor 1 increase can be monitored by monitoring the temperature of the compressor 1, mainly referring to the cooling circuit of the cooling circuit 9.

[0032] In some embodiments, in the above-mentioned mechanical refrigeration system, when in use, when the compressor 1 needs to start cooling, that is, at this time, the main circuit system where the compressor 1 is located has started to work, and at this time, the outlet of the throttling device 3 has already flowed out low-temperature refrigerant, which can meet the use requirements, and the cooling power requirements of the cooling circuit 9 can be adjusted by adjusting the opening degree of the flow control valve to adjust the incoming refrigerant flow, and then adjust the cooling power, so that the cooling needs can be met. The use of a flow control valve is relatively low in cost compared to the throttling device 3, and reducing the number of throttling devices 3 can better reduce energy consumption, while meeting the cooling time requirements and the cooling power precise control requirements, so as to be able to meet the use requirements well. In summary, the mechanical refrigeration system can effectively solve the problem of relatively high energy consumption of the current mechanical refrigeration system.

[0033] In some embodiments, in order to better control the temperature at the compressor 1, a temperature detector is preferably included here, wherein the temperature detector is used to detect the temperature at the compressor 1. As mentioned above, it mainly detects the temperature at the cooling object of the cooling circuit 9 to determine whether the cooling power of the cooling circuit 9 meets the requirements. If the temperature at the cooling object of the cooling circuit 9 meets the preset value, it means that the current cooling power meets the requirements, and the first flow control valve 5 does not need to be adjusted at this time; if the temperature at the cooling object of the cooling circuit 9 exceeds the preset value, it means that the current cooling power does not meet the requirements. At this time, the first flow control valve 5 needs to increase the flow rate accordingly until the temperature at the cooling object of the cooling circuit 9 meets the preset value. Of course, if the temperature at the compressor 1 is too low, if the cooling circuit 9 maintains the current cooling power at this time, energy loss will be caused. Based on this, if the temperature at the cooling object of the cooling circuit 9 is lower than the preset value, it means that the current cooling power is too large. At this time, the first flow control valve 5 needs to reduce the flow rate accordingly until the temperature at the cooling object of the cooling circuit 9 meets the preset value or the first flow control valve 5 is closed. The preset value is generally a range value, and of course it can also be a single value. The specific range can be obtained according to the performance requirements of the actual compressor 1 and the ambient temperature of use.

[0034] In some embodiments, it is preferred that the first flow control valve 5 is linked with the temperature detector to adjust the opening according to the temperature change so as to achieve automatic control. How to achieve linkage between the flow control valve and the temperature detector can generally be obtained through existing technology. For example, it is generally with the help of a controller, which acts as a judgment control mechanism to obtain the temperature detection value from the temperature detector, compare it with the pre-stored predetermined value, and control the first flow control valve 5 accordingly according to the comparison structure and the above method. At this time, the opening of the first flow control valve 5 can be graded, and the opening of the first flow control valve 5 can be increased or decreased, and the increase or decrease can be achieved step by step, and the controller makes a judgment at each level. Of course, the controller can also be based on the difference between the current detection value and the preset value, according to the table lookup, and the corresponding control of the increase or decrease of the opening of the first flow control valve 5.

[0035] In some examples, the cooling efficiency of the cooling circuit 9 is not only related to the flow rate of the fluid, but also to the flow rate of the fluid. The greater the flow rate, the higher the cooling efficiency. The flow rate in the cooling circuit 9 is related to the pressure. When in use, the outlet pressure of the throttling device 3 may not be large enough, resulting in a poor cooling effect of the cooling circuit 9. Based on this, it is preferred that a booster pump 6 is also included here, and the booster pump is used to accelerate the fluid in the channel between the throttling device 3 and the evaporator 4 to be pumped to the cooling circuit 9, so as to increase the fluid speed in the cooling circuit 9, thereby improving the cooling efficiency of the cooling circuit 9.

[0036] It should be noted that the booster pump 6 can also be linked with the above-mentioned temperature detector, can be linked alone, or can be controlled together with the above-mentioned first flow control valve 5. The separate linkage mode can refer to the linkage mode between the above-mentioned first flow control valve 5 and the temperature detector. Generally speaking, when the detection value of the temperature detector exceeds the set temperature value, the booster pump 6 is started. When the booster pump 6 is a pressure adjustable pump (speed adjustable pump), of course, after the booster pump 6 is started, the power of the booster pump 6 can also be increased as the detection value of the temperature detector increases.

[0037] The first flow control valve 5, the booster pump 6 and the temperature detector are linked together. Generally speaking, as the detection value of the temperature detector increases, the first flow control valve 5 is opened first; and as the detection value of the temperature detector increases, the opening of the first flow control valve 5 gradually increases. When the opening of the first flow control valve 5 reaches the set value or the maximum value, the booster pump 6 starts to start. After the booster pump 6 is started, it can be adjusted accordingly according to different communication modes. For details, please refer to the following embodiments.

[0038] After the boost pump 6 is provided, the outlet of the cooling circuit 9 can be connected between the evaporator 4 and the throttling device 3 to increase the pressure by the boost pump 6 .

[0039] In some embodiments, the boost pump 6 and the first flow control valve 5 can be arranged in series, and the boost pump 6 can be connected between the first flow control valve 5 and the cooling circuit 9, or the first flow control valve 5 can be connected between the boost pump 6 and the cooling circuit 9. The first flow control valve 5 and the boost pump 6 are connected in series, so that after the first flow control valve 5 expands the flow, the cooling power of the cooling circuit 9 still cannot meet the requirements. Then the boost pump 6 can be started at this time, and after the boost pump 6 is started, the opening of the first flow control valve 5 reaches the set value or the maximum value. If the temperature detector detects a value that further increases: in some embodiments, if the boost pump 6 can increase the power, the boost pump 6 can be controlled to increase the power; if the boost pump 6 cannot increase the power and the first flow control valve 5 does not reach the maximum opening, the first flow control valve 5 can be made to increase the opening. In the series state, in some embodiments, in some stages, as the temperature detector detects a value that increases, the power of the boost pump 6 remains unchanged, but the opening of the first flow control valve 5 increases.

[0040] In some embodiments, the boost pump 6 and the first flow control valve 5 can be arranged in parallel, but a one-way valve should be arranged on the branch where the first flow control valve 5 is located to avoid reverse flow. A one-way valve may be arranged on the branch where the boost pump 6 is located, or a one-way valve may not be arranged, but a switch valve is preferably arranged. By arranging in parallel, the first flow control valve 5 can be avoided, and the pumping power of the boost pump 6 can be limited.

[0041] In some embodiments, further, the outlet of the cooling circuit 9 can be connected between the evaporator 4 and the compressor 1, so that the outlet pressure of the cooling circuit 9 is lower, so as to reduce the use frequency of the booster pump 6 or avoid installing the booster pump 6. And the outlet connection position of the cooling circuit 9 is set close to the evaporator 4, that is, the flow distance of the fluid from the evaporator 4 to the above-mentioned connection position is longer than the flow distance of the fluid from the above-mentioned connection position to the compressor 1. That is, the above-mentioned close to the evaporator 4 is based on the fluid flow path.

[0042] In some embodiments, an economizer 7 is generally provided in the main system. The economizer 7 is mainly installed between the condenser 2 and the throttling device 3. The economizer 7 includes a first channel and a second channel that can exchange heat with each other. The first channel of the economizer 7 is connected between the condenser 2 and the throttling device 3 as a part of the main circuit, and a low-temperature refrigerant flows into the second channel of the economizer 7. Heat is exchanged between the two channels of the economizer 7 so that the refrigerant in the main circuit begins to cool down. The refrigerant that absorbs heat in the second channel can be introduced into the inlet of the compressor 1.

[0043] For the compressor 1, a multi-stage compression part is generally provided. Specifically, the compressor 1 includes a low-stage compression part and a high-stage compression part connected in series through a progressive passage along the fluid flow direction. Of course, in addition to the above-mentioned low-stage compression part and high-stage compression part, more stage compression parts can be provided. Even other stage compression parts can be provided between the low-stage compression part and the high-stage compression part. In this case, the progressive passage is not directly connected to at least one of the low-stage compression part and the high-stage compression part, but is indirectly connected through other stage compression parts.

[0044] The refrigerant absorbing heat in the second channel can be introduced into the inlet of the compressor 1 or into the above-mentioned progressive channel for air replenishment. Specifically, the outlet of one end of the second channel of the economizer 7 is connected to the progressive channel, and a one-way valve is correspondingly provided.

[0045] The source of the refrigerant of the economizer 7 may also come from a separately arranged expansion valve. In order to reduce energy consumption, it is preferred that the inlet of the second channel is connected to the outlet of the booster pump 6, so that the low-temperature refrigerant flowing out of the booster pump 6 is introduced into the economizer 7 to cool the main path, and then introduced into the progressive channel after cooling the main path, and after being pressurized by the supercharger, it can better meet the needs of the progressive channel.

[0046] In some examples, the outlet of the booster pump 6 divides the fluid to the cooling circuit 9 and the second channel through a flow splitting structure, so as to supply gas to the cooling circuit 9 and the second channel at the same time. The flow splitting structure, such as a three-way structure, can also be a three-way valve.

[0047] In some examples, it is preferred that a switch valve or a first flow control valve 5 is provided between the shunt structure and the cooling circuit 9. Specifically, a switch valve may be provided between the shunt structure and the cooling circuit 9, and at this time, the boost pump 6 and the first flow control valve 5 are in parallel, so the switch valve, the first flow control valve 5 and the cooling circuit 9 are connected through a three-way structure. If the first flow control valve 5 is provided between the shunt structure and the cooling circuit 9, then the first flow control valve 5 and the boost pump 6 are in series at this time. By providing the first flow control valve 5 or the switch valve between the shunt structure and the cooling circuit 9, the corresponding flow can be changed by controlling the above-mentioned flow control valve or the switch valve without changing the power of the boost pump 6 or the flow of the second channel, so as to separately adjust the flow in the cooling circuit 9.

[0048] In some examples, it is preferred that a second flow control valve 8 is further provided between the flow dividing structure and the second channel, so as to separately adjust the amount of refrigerant entering the second channel. Furthermore, a pressure sensor may be provided at the progressive channel, and when the pressure sensor is lower than a preset value, the second flow valve is controlled to increase the flow, and at this time, the booster pump 6 correspondingly increases the power to better replenish the gas.

[0049] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0050] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A mechanical refrigeration system, comprising a compressor, a condenser, a throttling device and an evaporator connected in sequence, wherein the compressor has a cooling circuit, characterized in that: The cooling circuit inlet is connected to the passage between the throttling device and the evaporator through a first flow control valve.

2. The mechanical refrigeration system according to claim 1, characterized in that: It also includes a temperature detector for detecting the temperature at the compressor, and the first flow control valve is linked with the temperature detector to adjust the opening degree according to the temperature change.

3. The mechanical refrigeration system according to claim 1, characterized in that: The device also includes a booster pump, which is used to accelerate the pumping of the fluid on the channel between the throttling device and the evaporator to the cooling circuit.

4. The mechanical refrigeration system according to claim 3, characterized in that: The boost pump and the first flow control valve are arranged in series.

5. The mechanical refrigeration system according to claim 4, characterized in that: The boost pump and the first flow control valve are arranged in parallel, and a one-way valve is connected in series at the first flow control valve.

6. The mechanical refrigeration system according to claim 5, characterized in that: The outlet of the cooling circuit is connected between the evaporator and the compressor and is arranged close to the evaporator.

7. The mechanical refrigeration system according to any one of claims 3 to 6, characterized in that: It also includes an economizer, the compressor includes a low-stage compression part and a high-stage compression part connected in series through a progressive channel along the fluid flow direction, the first channel of the economizer is connected between the condenser and the throttling device; the outlet of one end of the second channel of the economizer is connected to the progressive channel.

8. The mechanical refrigeration system according to claim 7, characterized in that: The inlet of the second passage is connected to the outlet of the boost pump.

9. The mechanical refrigeration system according to claim 8, characterized in that: The outlet of the boost pump divides the fluid to the cooling circuit and the second channel through a flow dividing structure, and a switch valve or the first flow control valve is arranged between the flow dividing structure and the cooling circuit.

10. The mechanical refrigeration system according to claim 9, characterized in that: A second flow control valve is arranged between the flow dividing structure and the second channel.

Images