Water chilling unit and air conditioning system

Abstract

The invention provides a water chilling unit which comprises a compressor, a condenser, a first throttling element and an evaporator, the compressor comprises a first enhanced vapor injection compressor and a second enhanced vapor injection compressor which are connected in parallel, and the water chilling unit further comprises a second throttling element, a third throttling element, an economizer, a first manifold and a second manifold. The economizer comprises a first heat exchange flow path, a second heat exchange flow path and a third heat exchange flow path, the second heat exchange flow path and the third heat exchange flow path exchange heat with the first heat exchange flow path, the first heat exchange flow path is connected between the condenser and the first throttling element, and the first manifold and the second manifold are connected between the first throttling element and the condenser; the first manifold sequentially communicates with the second throttling element, the second heat exchange flow path and the first air supply port. The second manifold sequentially communicates with the third throttling element, the third heat exchange flow path and the second air supply port. According to the water chilling unit, the problem of refrigerant backflow between the air supply ports can be solved, and meanwhile the cost of the water chilling unit is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and particularly to a water chiller and an air conditioning system. Background Art

[0002] The jet enthalpy increase technology has been widely applied at present to solve the problem that the heating capacity significantly decreases in the low-temperature environment in winter. In order to increase the heating capacity, some large and medium-sized water chillers use multiple jet enthalpy increase compressors in parallel.

[0003] In order to be able to use multiple jet enthalpy increase compressors in parallel when the heating demand is high, and be able to use only some jet enthalpy increase compressors when the heating demand is low, and prevent the refrigerant with the intermediate pressure at the gas injection port of the activated jet enthalpy increase compressor from flowing back to the gas injection port of the deactivated jet enthalpy increase compressor, in the prior art, solenoid valves are provided in each branch between the economizer and the gas injection port of the jet enthalpy increase compressor. However, setting multiple solenoid valves will increase the cost. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to reduce the cost of the water chiller while solving the problem of refrigerant reflux between the gas injection ports for a water chiller using multiple jet enthalpy increase compressors in parallel.

[0005] In view of the above problems, a first aspect of the present invention provides a water chiller, including a compressor, a condenser, a first throttling element, and an evaporator. The compressor includes a first jet enthalpy increase compressor and a second jet enthalpy increase compressor connected in parallel. The first jet enthalpy increase compressor has a first gas injection port, and the second jet enthalpy increase compressor has a second gas injection port. The water chiller further includes a second throttling element, a third throttling element, an economizer, a first manifold, and a second manifold. The economizer includes a first heat exchange flow path, a second heat exchange flow path, and a third heat exchange flow path. The second heat exchange flow path and the third heat exchange flow path both exchange heat with the first heat exchange flow path. The first heat exchange flow path is connected between the condenser and the first throttling element; the first manifold is connected between the first throttling element and the condenser, and the first manifold sequentially communicates with the second throttling element, the second heat exchange flow path, and the first gas injection port; the second manifold is connected between the first throttling element and the condenser, and the second manifold sequentially communicates with the third throttling element, the third heat exchange flow path, and the second gas injection port.

[0006] Optionally, both the first manifold and the second manifold are connected between the first throttling element and the first heat exchange flow path.

[0007] Optionally, both the first manifold and the second manifold are connected between the condenser and the first heat exchange flow path. Optionally, the first manifold is connected between the condenser and the first heat exchange flow path, and the second manifold is connected between the first throttling element and the first heat exchange flow path.

[0008] Optionally, no solenoid valve is provided between the first air supply port and the second heat exchange flow path, and no solenoid valve is provided between the second air supply port and the third heat exchange flow path.

[0009] Optionally, the economizer is a plate heat exchanger.

[0010] Optionally, the first jet reheat compressor and the second jet reheat compressor are started selectively or simultaneously.

[0011] A second aspect of the present invention provides an air-conditioning system having the chiller provided by the first aspect of the present invention.

[0012] On the premise that the problem of refrigerant backflow between the air supply ports can be solved, compared with the solution in the prior art that uses two solenoid valves and two expansion valves (including an expansion valve as the main throttling element in the main flow path), the chiller provided by the present invention can save the additional cost brought by the use of solenoid valves, avoid the generation of solenoid valve throttling effect, and improve control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of a chiller in the prior art.

[0014] Figure 2 This is a system diagram of a chiller according to a first embodiment of the present invention.

[0015] Figure 3 This is a system diagram of a chiller according to a second embodiment of the present invention.

[0016] Figure numbers: 100, 200, 300-chiller; 1-evaporator; 2-condenser; 3-economizer; 31-economizer main channel inlet; 32-economizer main channel outlet; 4-jet reheat compressor; 40-air supply port; 41-first jet reheat compressor; 411-first air supply port; 42-second jet reheat compressor; 421-second air supply port; 43-compressor exhaust port; 44-compressor intake port; 51-first solenoid valve; 52-second solenoid valve; 61-first heat exchange flow path; 62 second heat exchange flow path; 63-third heat exchange flow path; 71-first throttling element; 72-second throttling element; 73-third throttling element; 74-manifold; 81-first manifold; 82-second manifold. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] <Prior Art>

[0019] First, the prior art will be described in more detail with reference to the accompanying drawings. Figure 1 A chiller 100 having a plurality of parallel jet enthalpy compressors 4 is a prior art.

[0020] Reference Figure 1 In the chiller 100 provided by the prior art, each gas injection port 40 of the jet enthalpy compressor 4 is connected to a solenoid valve (i.e., the first solenoid valve 51 and the second solenoid valve 52). Specifically, the chiller 100 includes a first jet enthalpy compressor 41 and a second jet enthalpy compressor 42, a condenser 2, an economizer 3, a first throttling element 71, and an evaporator 1. The gas injection ports 40 of the first jet enthalpy compressor 41 and the second jet enthalpy compressor 42 are respectively connected to the first solenoid valve 51 and the second solenoid valve 52.

[0021] The economizer 3 includes a first heat exchange flow path 61 and a second heat exchange flow path 62. A first throttling element 71 is provided in the pipeline connecting the evaporator 1 and the first heat exchange flow path 61. A manifold 74 is connected between the first heat exchange flow path 61 and the first throttling element 71. The manifold 74 is connected to the second heat exchange flow path 62. A second throttling element 72 is provided in the manifold 74. Both the first throttling element 71 and the third throttling element 72 are expansion valves.

[0022] When multiple jet enthalpy compressors 4 need to operate synchronously, the refrigerant amounts of the two branches can be controlled by the first solenoid valve 51 and the second solenoid valve 52 respectively. When one of the jet enthalpy compressors 4 is turned off, the corresponding first solenoid valve 51 or second solenoid valve 52 can be closed to prevent the cross-flow or backflow of the medium-pressure refrigerant between the gas injection ports 40. However, because a relatively large number of solenoid valves (the first solenoid valve 51 and the second solenoid valve 52) are used, the cost will also increase. In addition, the solenoid valve also has problems such as throttling effect and poor control accuracy.

[0023] <The First Embodiment>

[0024] This embodiment provides a chiller 200. As Figure 2 shown, the chiller 200 includes two mutually parallel jet enthalpy compressors 4 (i.e., the first jet enthalpy compressor 41 and the second jet enthalpy compressor 42), a condenser 2, an economizer 3, a first throttling element 71, and an evaporator 1. In this embodiment, the number of mutually parallel jet enthalpy compressors 4 is two. In other embodiments, the number of parallel jet enthalpy compressors 4 can also be three or more. The number of jet enthalpy compressors 4 is not limited in this embodiment.

[0025] The jet - enhanced enthalpy compressor 4 has a compressor discharge port 43 and a compressor suction port 44. The compressor discharge port 43 is connected to the condenser 2, and the compressor suction port 44 is connected to the evaporator 1. In some embodiments, the compressor discharge ports 43 of the jet - enhanced enthalpy compressor 4 can be interconnected and then connected to the condenser 2, or can be connected to the condenser 2 via a pipeline system that can adjust the refrigerant mixing and distribution. In the attached drawings of the specification of this application, the connection between the jet - enhanced enthalpy compressor 4 and the evaporator 1 and the condenser 2 is not shown.

[0026] An economizer 3 is provided between the condenser 2 and the first throttling element 71. The economizer 3 has a first heat - exchange flow path 61, a second heat - exchange flow path 62, and a third heat - exchange flow path 63. Among them, the first heat - exchange flow path 61 is connected to the main flow path of the refrigerant flow circuit, that is, connected between the condenser 2 and the first throttling element 71. The two ends of the first heat - exchange flow path 61 are respectively an economizer main - flow - path inlet 31 and an economizer main - flow - path outlet 32. Referring to Figure 2 , the economizer main - flow - path inlet 31 is connected to the refrigerant outlet of the condenser 2, and the economizer main - flow - path outlet 32 is connected to the refrigerant inlet of the evaporator 1 via the first throttling element 71.

[0027] Both the second heat - exchange flow path 62 and the third heat - exchange flow path 63 are coupled to the first heat - exchange flow path 61. The refrigerant whose temperature is reduced by throttling expansion through the second throttling element 72 in the second heat - exchange flow path 62, and / or the refrigerant whose temperature is reduced by throttling expansion through the third throttling element 73 in the third heat - exchange flow path 63, will exchange heat with the relatively higher - temperature refrigerant in the first heat - exchange flow path 61.

[0028] In this embodiment, the water chiller 200 includes two manifolds connected to the outlet side of the first heat - exchange flow path 61 of the economizer 3, specifically the first manifold 81 and the second manifold 82. Among them, the first manifold 81 is sequentially connected to the second throttling element 72, the second heat - exchange flow path 62, and the first air - supplement port 411; the second manifold 82 is sequentially connected to the third throttling element 73, the third heat - exchange flow path 63, and the second air - supplement port 421. Because two independent branches are used to supplement air for the first jet - enhanced enthalpy compressor 41 and the second jet - enhanced enthalpy compressor 42 respectively, the first manifold 81 and the second manifold 82 are formed by splitting at the inlet side or the outlet side of the first heat - exchange flow path 61. The splitting point (i.e., the connection between the first manifold 81 and the second manifold 82 and the main flow path) is separated from the air - supplement port by the second throttling element 72 (or the third throttling element 73) and the economizer 3. Therefore, when some of the jet - enhanced enthalpy compressors 4 are turned off, by closing the corresponding second throttling element 72 or third throttling element 73, the cross - flow of the medium - pressure refrigerant between multiple air - supplement ports can also be prevented.

[0029] In this embodiment, the first throttling element 71, the second throttling element 72, and the third throttling element 73 are all expansion valves. Relative to Figure 1Compared with the prior art which uses two solenoid valves and two expansion valves (including an expansion valve as the main throttling element in the main flow path), the chiller 200 provided in this embodiment can save the additional cost caused by the use of solenoid valves, and can effectively avoid the generation of throttling effect, and can accurately adjust the corresponding jet reheat compressor 4 separately through the second throttling element 72 or the third throttling element 73 to improve the control accuracy.

[0030] The first jet reheat compressor 41 and the second jet reheat compressor 42 can use jet reheat compressors 4 of the same capacity, or jet reheat compressors 4 of different capacities. In this embodiment, by independently and accurately controlling the openings of the second throttling element 72 and the third throttling element 73, the refrigerant entering the compressor air supply port is medium-temperature medium-pressure steam with a suitable flow rate and flow velocity. By adjusting the opening of the throttling element connected to the compressor air supply port, especially by independently regulating the compressor according to the different working conditions of each compressor, the control accuracy can be improved, the system stability can be improved, and the control needs of the multiple jet reheat compressors 4 connected in parallel with different working conditions can be effectively met.

[0031] refer to Figure 2 When the system is in operation, after the refrigerant flows out of the outlet of the condenser 2, it is split by the first manifold 81 and the second manifold 82 before flowing into the inlet of the first throttling element 71. The split refrigerant expands and releases heat by passing through the second throttling element 72 and the third throttling element 73 respectively. The refrigerant after heat release and cooling can cool the refrigerant in the first heat exchange flow path 61 of the main channel. On the one hand, the refrigerant in the first heat exchange flow path 61 can be cooled to a reasonable temperature before entering the first throttling element 71, and on the other hand, the temperature of the refrigerant entering the air supply port can be accurately controlled.

[0032] In this embodiment, after the refrigerant flows through the condenser 2, a portion of the refrigerant first passes through the first heat exchange path 61 of the economizer 3, then expands and releases heat through the first throttling element 71. It then absorbs heat through the evaporator 1 before returning to the jet regenerative compressor 4, entering the compressors through the intake ports of both compressors for a single-stage compression. Another portion of the refrigerant is split before the first throttling element 71 and enters the first manifold 81 and the second manifold 82, respectively. After expanding and releasing heat through the second throttling element 72 and the third throttling element 73, respectively, it then passes through the second heat exchange path 62 and the third heat exchange path 63, respectively, exchanging heat with the refrigerant in the first heat exchange path 61. It then enters the first air supply port 411 of the first jet regenerative compressor 41 and the second air supply port 421 of the second jet regenerative compressor 42, respectively. It then mixes with the refrigerant that has been compressed to medium temperature and medium pressure after entering the compressor intake port 44 and undergoes a second-stage compression, producing high-temperature and high-pressure refrigerant, which ultimately flows out of the compressor exhaust port 43.

[0033] In this embodiment, the refrigerant after flow splitting enters the second heat exchange flow path 62 and the third heat exchange flow path 63 respectively after expanding and releasing heat. The flow direction of the refrigerant in the second heat exchange flow path 62 and the third heat exchange flow path 63 is opposite to that of the refrigerant in the first heat exchange flow path 61. The reverse flow can improve the heat exchange effect. In some embodiments, the flow direction of the refrigerant in the second heat exchange flow path 62 and the third heat exchange flow path 63 may also be the same as that of the refrigerant in the first heat exchange flow path 61. This embodiment does not limit this.

[0034] <Second Embodiment>

[0035] This embodiment provides a water chiller 300 in which a first manifold 81 and a second manifold 82 are both connected between a condenser 2 and a first heat exchange flow path 61.

[0036] The structure of the economizer 3 is the same as that of the above-mentioned first embodiment and will not be elaborated here. Refer to Figure 3 , the refrigerant flowing out of the condenser 2 is split at the splitting point. A part of the refrigerant directly flows from the economizer main flow path inlet 31 of the economizer 3 to the first heat exchange flow path 61; another part of the refrigerant enters the first manifold 81 and the second manifold 82 respectively, expands and releases heat first through the second throttling element 72 and the third throttling element 73, and then flows into the second heat exchange flow path 62 and the third heat exchange flow path 63 respectively to further cool the refrigerant in the first heat exchange flow path 61, and then flows out of the economizer 3, and finally flows to the first gas injection port 411 and the second gas injection port 422 of the jet injection compressor 4 respectively.

[0037] In this embodiment, the flow direction of the refrigerant in the second heat exchange flow path 62 and the third heat exchange flow path 63 is the same as that of the refrigerant in the first heat exchange flow path 61. In some embodiments, the flow direction of the refrigerant in the second heat exchange flow path 62 and the third heat exchange flow path 63 may also be opposite to that of the refrigerant in the first heat exchange flow path 61.

[0038] This solution sets the splitting point on the inlet side of the economizer 3, that is, between the economizer main flow path inlet 31 and the condenser 2. After the refrigerant flows out of the condenser 2 outlet, it does not need to pass through the first heat exchange flow path 61 and is directly split at the splitting point. The split part expands and releases heat and then cools the refrigerant in the first heat exchange flow path 61, and finally flows into the gas injection port of the compressor. The way of splitting first and then exchanging heat can increase the temperature difference between the heat exchange pipelines and improve the cooling efficiency of the refrigerant in the first heat exchange flow path 61.

[0039] The first and second embodiments respectively show the situations where the diversion points are located before and after the economizer 3. In some other embodiments, some diversion points can also be set before the economizer 3, and some diversion points can be set after the economizer 3, that is, the first manifold 81 can be connected between the condenser 2 and the first heat exchange flow path 61, and the second manifold 82 can be connected between the first throttling element 71 and the first heat exchange flow path 61.

[0040] In the above embodiment of the present invention, the economizer 3 may be a plate heat exchanger.

[0041] In the above embodiment of the present invention, the first reheat injection compressor 41 and the second reheat injection compressor 42 can be started selectively or simultaneously. Figure 2 and Figure 3 In the embodiment of the present invention, since the diversion point is located on the side of the economizer away from the air supply port, the first jet reheat compressor 41 and the second jet reheat compressor 42 can prevent refrigerant cross-flow or backflow by closing the second throttling element 72 or the third throttling element 73 during the process of opening and closing or opening at the same time.

[0042] Through the above approach, the temperature and flow rate of the medium-pressure refrigerant entering the first air supply port 411 and the second air supply port 421 can be independently and precisely adjusted. When only a portion of the jet reheat compressor 4 is required to operate, backflow or cross-flow of the medium-pressure refrigerant between the air supply ports will not occur. With the above-mentioned issues resolved, the chillers 200 and 300 provided in the above embodiments also reduce the use of solenoid valves, lowering costs and avoiding the throttling effect and low control accuracy associated with solenoid valves.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A water chiller, comprising a compressor, a condenser, a first throttling element and an evaporator, wherein the compressor comprises a first jet-enhanced enthalpy compressor and a second jet-enhanced enthalpy compressor connected in parallel, the first jet-enhanced enthalpy compressor has a first gas supplement port, and the second jet-enhanced enthalpy compressor has a second gas supplement port, and is characterized in that, The chiller further includes: A second throttling element; A third throttling element; An economizer, the economizer includes a first heat exchange flow path, a second heat exchange flow path and a third heat exchange flow path, the second heat exchange flow path and the third heat exchange flow path both exchange heat with the first heat exchange flow path, and the first heat exchange flow path is connected between the condenser and the first throttle valve; A first manifold, connected between the first throttle valve and the condenser, and the first manifold sequentially communicates with the second throttling element, the second heat exchange flow path and the first air supply port; A second manifold, connected between the first throttle valve and the condenser, and the second manifold sequentially communicates with the third throttling element, the third heat exchange flow path and the second air supply port.

2. The chiller according to claim 1, characterized in that, Both the first manifold and the second manifold are connected between the first throttling element and the first heat exchange flow path.

3. The chiller according to claim 1, characterized in that, Both the first manifold and the second manifold are connected between the condenser and the first heat exchange flow path.

4. The chiller according to claim 1, characterized in that, No solenoid valve is provided between the first air supply port and the second heat exchange flow path, and no solenoid valve is provided between the second air supply port and the third heat exchange flow path.

5. The chiller according to claim 1, characterized in that, The economizer is a plate heat exchanger.

6. The chiller according to claim 1, characterized in that, Either the first jet enthalpy-increasing compressor or the second jet enthalpy-increasing compressor is turned on or both are turned on simultaneously.

7. An air conditioning system, characterized in that, The air conditioning system includes the chiller according to any one of claims 1-6.

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