Method for controlling a chiller-heater unit, device and chiller-heater unit

Abstract

The application relates to the air conditioning technical field, and discloses a method and device for controlling a cold-heat unit and the cold-heat unit. The cold-heat unit comprises a compressor, a condenser, a first economizer and a second economizer. The first economizer is communicated with the outlet of the condenser. The outlet of the evaporating part of the first economizer is communicated with the inlet of the second economizer. The upstream of the evaporator part of the second economizer is provided with a second electronic expansion valve. The outlet of the evaporating part of the second economizer is communicated with the medium-pressure cabin of the compressor. The outlet of the evaporating part of the first economizer and / or the evaporating part of the second economizer is communicated with the low-pressure cabin of the compressor. The method comprises the following steps: obtaining the outlet refrigerant temperature of the evaporating part of the first economizer; confirming the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer according to the outlet refrigerant temperature of the evaporating part of the first economizer; and controlling the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer. The operation efficiency of the cold-heat unit considering both heating and refrigeration is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the air conditioning technical field, for example, relates to a kind of for controlling cold and hot unit and the method, device and cold and hot unit of heat unit. BACKGROUND

[0002] Due to the comfort and energy-saving and environmental protection features of the two-coupled supply system, it is more and more popular with users, in order to meet the demand of northern market, low temperature type (-37℃) machine gradually becomes the research object of each big factory, and the air supplement and enthalpy increasing system can effectively solve the low temperature heating problem, but the air supplement and enthalpy increasing system is often only applied to heating operation. When heating, reduce the exhaust temperature, prevent overheating, and when cooling, only for supercooling degree.

[0003] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

[0004] In the related art, in order to prevent overheating when heating, the air supplement and enthalpy increasing system is not fully and effectively utilized. Especially when heating, the air supplement amount control is not accurate, which has the opposite effect, and the compressor liquid knock phenomenon may occur.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] To have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not a general review, nor does it determine the key / important elements or delineate the scope of protection of these embodiments, but serves as a prelude to the detailed description below.

[0007] The embodiments of the present disclosure provide a kind of for controlling cold and hot unit and the method, device and cold and hot unit of heat unit, realize effectively solve low temperature heating problem, also can be applied to refrigeration, increase supercooling degree, while reducing exhaust temperature when high temperature operation to prevent system report high temperature and high pressure fault, make system safe and reliable operation.

[0008] The embodiment of the present disclosure provides a method for controlling a cold and heat unit, the cold and heat unit comprising a compressor, a condenser, a first economizer and a second economizer, the first economizer being communicated with an outlet of the condenser, an outlet of an evaporating part of the first economizer being communicated with an inlet of the second economizer, a second electronic expansion valve being arranged upstream of an evaporator part of the second economizer, the outlet of the evaporating part of the second economizer being communicated with a medium-pressure cabin of the compressor, the outlet of the evaporating part of the first economizer and / or the outlet of the evaporating part of the second economizer being communicated with a low-pressure cabin of the compressor; the method comprising: obtaining a refrigerant temperature at the outlet of the evaporating part of the first economizer; confirming an evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer according to the refrigerant temperature at the outlet of the evaporating part of the first economizer; and controlling an opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer.

[0009] Optionally, the confirming the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer according to the refrigerant temperature at the outlet of the evaporating part of the first economizer comprises: confirming that the refrigerant at the outlet of the evaporating part of the first economizer is not completely evaporated when the refrigerant temperature at the outlet of the evaporating part of the first economizer is less than an evaporation temperature threshold; and confirming that the refrigerant at the outlet of the evaporating part of the first economizer is completely evaporated when the refrigerant temperature at the outlet of the evaporating part of the first economizer is greater than or equal to the evaporation temperature threshold.

[0010] Optionally, the controlling the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer comprises: controlling the second electronic expansion valve to decrease the opening degree when the refrigerant at the outlet of the evaporating part of the first economizer is not completely evaporated; and controlling the second electronic expansion valve to reset and increase the opening degree until the refrigerant temperature at the outlet of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold when the opening degree of the second electronic expansion valve is decreased to a second opening degree and the real-time refrigerant temperature at the outlet of the evaporating part of the second economizer is less than the evaporation temperature threshold.

[0011] Optionally, the cold and heat unit further comprises a gas-liquid separator, a first branch and a second branch, the first branch being communicated between the outlet of the evaporating part of the second economizer and the medium-pressure cabin of the compressor, the second branch being communicated between the outlet of the evaporating part of the first economizer and the inlet of the gas-liquid separator, the first branch being provided with a first control valve, the second branch being provided with a second control valve, and a condensing part of the second economizer being arranged in the second branch; and the method further comprises: obtaining an exhaust temperature of the compressor or a low-pressure pressure of the cold and heat unit after the refrigerant temperature at the outlet of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold; and controlling the opening degrees of the second electronic expansion valve, the first control valve and the second control valve according to the exhaust temperature of the compressor or the low-pressure pressure of the cold and heat unit.

[0012] Optionally, after the processor controls the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer, the method further comprises:

[0013] In a case where the outlet refrigerant temperature of the evaporation section of the second economizer is greater than or equal to the evaporation temperature threshold, the high-pressure pressure and the low-pressure pressure of the chiller-heater unit are obtained;

[0014] According to the high-pressure pressure and the low-pressure pressure of the chiller-heater unit, the compression ratio of the chiller-heater unit is confirmed;

[0015] In a case where the compression ratio of the chiller-heater unit is greater than the optimal compression ratio, the processor controls the second electronic expansion valve to maintain the opening degree, and controls the first control valve to open and the second control valve to close;

[0016] In a case where the high-pressure pressure of the chiller-heater unit is less than the pressure threshold, the second control valve is controlled to open until the compressor of the chiller-heater unit reaches the optimal compression ratio.

[0017] Optionally, according to the exhaust temperature of the compressor or the low-pressure pressure of the chiller-heater unit, the opening degrees of the second electronic expansion valve, the first control valve and the second control valve are controlled, including: in a case where the low-pressure pressure of the chiller-heater unit is less than or equal to a preset pressure, the second electronic expansion valve is controlled to fully open or close, and the second control valve is controlled to open; or in a case where the exhaust temperature of the compressor is greater than or equal to a preset temperature, the second electronic expansion valve is controlled to maintain the opening degree, and the first control valve is controlled to open and the second control valve is controlled to close.

[0018] Optionally, the upstream of the evaporation section of the first economizer is provided with a first electronic expansion valve, and before the outlet refrigerant temperature of the evaporation section of the first economizer is obtained, the method further includes: obtaining the inlet refrigerant temperature and the outlet refrigerant temperature of the condensation section of the first economizer; according to the inlet refrigerant temperature and the outlet refrigerant temperature of the condensation section of the first economizer, the opening degree of the first electronic expansion valve is controlled until the outlet refrigerant temperature of the condensation section of the first economizer is less than or equal to the condensation temperature threshold.

[0019] The embodiments of the present disclosure further provide a device for controlling a chiller-heater unit, comprising a processor and a memory storing program instructions, characterized in that the processor is configured to execute the method for controlling a chiller-heater unit as described in any one of the above embodiments when running the program instructions.

[0020] The embodiment of the present disclosure further provides a cold and heat unit, comprising: a refrigerant circulation loop, the refrigerant circulation loop comprising a compressor, a four-way valve, a condenser, a throttling device and an evaporator; a first economizer, a condensing part of the first economizer being communicated between the condenser and the throttling device, an inlet of an evaporating part of the first economizer being communicated with an outlet of the condenser; a first electronic expansion valve, the first electronic expansion valve being communicated with the evaporating part of the first economizer and being located upstream of the evaporating part of the first economizer; a second economizer, an inlet of an evaporating part and a condensing part of the second economizer being communicated with an outlet of the evaporating part of the first economizer; and a second electronic expansion valve, the second electronic expansion valve being communicated with the evaporating part of the second economizer and being located upstream of the evaporating part of the second economizer.

[0021] Optionally, the cold and heat unit further comprises: a gas-liquid separator, a gas outlet of the gas-liquid separator being communicated with a low-pressure cabin of the compressor; a first branch being communicated between an outlet of the evaporating part of the first economizer and an inlet of the gas-liquid separator; a second branch being communicated between an outlet of the evaporating part of the second economizer and a medium-pressure cabin of the compressor; a first control valve being arranged in the first branch and being used for controlling refrigerant flow of the first branch; and a second control valve being arranged in the second branch and being used for controlling refrigerant flow of the second branch.

[0022] The method and device for controlling a cold and heat unit and the cold and heat unit provided by the embodiment of the present disclosure can achieve the following technical effects:

[0023] The cold and heat unit of the embodiment of the present disclosure is provided with a first economizer and a second economizer, evaporated refrigerant flowing out of the evaporating part of the first economizer can flow into the second economizer, a second electronic expansion valve is arranged upstream of the evaporating part of the second economizer, and the second electronic expansion valve can throttle and cool the refrigerant flowing into the evaporating part of the second economizer. The refrigerant exchanged by the evaporating part and the condensing part of the second economizer can become gaseous, and the gaseous refrigerant can be supplemented into the low-pressure cabin or the medium-pressure cabin of the compressor. In this way, when the exhaust temperature of the compressor is too high, the gaseous refrigerant of the evaporating part of the second economizer can be transported into the medium-pressure cabin, the temperature of the gaseous refrigerant of the evaporating part of the second economizer is lower than the exhaust temperature of the compressor, and therefore the gaseous refrigerant can reduce the refrigerant temperature of the medium-pressure cabin after entering the medium-pressure cabin, so that the refrigerant is compressed twice, the operation efficiency is improved, and a large amount of liquid refrigerant is prevented from entering the compressor to cause liquid impact. In this way, the exhaust temperature of the compressor can be reduced for both heating and cooling, the refrigerant is compressed twice, and the operation efficiency is improved. Furthermore, when the cold and heat unit operates in heating mode, the low-pressure cabin of the compressor can be supplemented with air by the evaporating part of the second economizer and / or the evaporating part of the first economizer when the low-pressure of the cold and heat unit is low, the frosting speed of the outdoor heat exchanger is slowed down, and the heating capacity is improved. The refrigerant evaporated by the evaporating part of the first economizer enters the evaporating part of the second economizer again for heat exchange, so that the refrigerant flowing into the compressor is completely gaseous, and liquid refrigerant is prevented from entering the compressor to cause liquid impact.

[0024] When the cold and heat unit is running, the evaporation condition of the refrigerant at the outlet of the evaporation part of the first economizer can be confirmed according to the outlet refrigerant temperature of the evaporation part of the first economizer, and if the evaporation of the evaporation part of the first economizer is incomplete, the opening degree of the second electronic expansion valve can be controlled to ensure the gaseous integrity of the refrigerant flowing to the compressor. In this way, the normal operation of the cold and heat unit can be ensured, and the refrigerant of the compressor can be cooled during heating and cooling, improving the operating efficiency and preventing liquid strike of the compressor. The first economizer and / or the second economizer can also supplement air to the low-pressure cabin, slow down the frosting speed of the outdoor heat exchanger, and improve the heating capacity.

[0025] The foregoing general description and the following description are only exemplary and explanatory, and are not intended to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute a limitation on the embodiments, elements with the same reference numerals in the drawings are shown as similar elements, the drawings do not constitute a proportional limitation, and wherein:

[0027] Figure 1 is a structural schematic diagram of a cold and heat unit provided by an embodiment of the present disclosure;

[0028] Figure 2 is a schematic diagram of a method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0029] Figure 3 is a schematic diagram of another method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0030] Figure 4 is a schematic diagram of another method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0031] Figure 5 is a schematic diagram of another method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0032] Figure 6 is a schematic diagram of another method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0033] Figure 7 is a schematic diagram of another method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0034] Figure 8 is a schematic diagram of another method for controlling a cold and heat unit provided by an embodiment of the present disclosure;

[0035] Figure 9is a schematic diagram of an apparatus for controlling a cold and heat unit provided by an embodiment of the present disclosure.

[0036] Reference signs:

[0037] 10, compressor; 101, four-way valve; 102, indoor heat exchanger; 103, outdoor heat exchanger; 104, gas-liquid separator; 105, liquid accumulator; 1061, first throttling device; 1062, second throttling device; 107, high-pressure pressure sensor; 108, low-pressure pressure sensor; 20, first economizer; 201, first bypass pipeline; 202, electronic expansion valve; 203, first temperature sensor; 204, second temperature sensor; 205, third temperature sensor; 206, fourth temperature sensor; 207, first control valve; 2071, first branch; 208, second control valve; 2081, second branch; 209, fifth temperature sensor; 40, second economizer; 401, second electronic expansion valve; 402, second bypass pipeline; 90, apparatus for controlling a cold and heat unit; 900, processor; 901, memory; 902, communication interface; 903, bus. DETAILED DESCRIPTION

[0038] In order to enable a more detailed understanding of the features and technical content of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure is described in detail below, and the accompanying drawings are used for reference only, and do not limit the embodiments of the present disclosure. In the following technical description, in order to facilitate explanation, through multiple details, a sufficient understanding of the disclosed embodiments is provided. However, one or more embodiments can still be implemented without these details. In other cases, in order to simplify the drawings, well-known structures and devices can be simplified.

[0039] The terms "first", "second", and the like in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0040] Unless otherwise specified, the term "a plurality of" means two or more.

[0041] In the embodiments of the present disclosure, the character " / " represents an "or" relationship between the objects before and after it. For example, A / B represents: A or B.

[0042] The term "and / or" is a description of the association relationship between objects, which means that there can be three relationships. For example, A and / or B means: A or B, or, A and B, the three relationships.

[0043] The term "corresponding" can refer to a kind of association or binding relationship, A corresponding to B means that there is an association or binding relationship between A and B.

[0044] In combination Figure 1 As shown, the embodiment of the present disclosure provides a cold and heat unit, which comprises a refrigerant circulation loop, the refrigerant circulation loop comprises a compressor 10, a four-way valve 101, a condenser, a throttling device and an evaporator, high-temperature and high-pressure refrigerant flowing out of the compressor 10 flows into the condenser through the four-way valve 101, and after heat dissipation in the condenser, it flows into the throttling device for throttling. The throttled refrigerant becomes low-pressure refrigerant and flows into the evaporator. The refrigerant in the evaporator is evaporated to become gaseous refrigerant, and then flows into the compressor 10.

[0045] Optionally, the cold and heat unit comprises an indoor heat exchanger 102 and an outdoor heat exchanger 103. When the cold and heat unit is heating, the indoor heat exchanger 102 is the condenser, and the outdoor heat exchanger 103 is the evaporator. When the cold and heat unit is cooling, the indoor heat exchanger 102 is the evaporator, and the outdoor heat exchanger 103 is the condenser.

[0046] Optionally, the cold and heat unit further comprises a first bypass pipeline 201 and a first economizer 20. The inlet of the first bypass pipeline 201 is in communication with the outlet of the condenser, and the outlet of the first bypass pipeline 201 is capable of being in communication with the compressor 10. The cold and heat unit further comprises a first economizer 20 and a first electronic expansion valve 202. The first economizer 20 and the first electronic expansion valve 202 are both arranged in the first bypass pipeline 201. The first economizer 20 comprises an evaporating part of the first economizer 20 and a condensing part of the first economizer 20 which exchange heat with each other, and the first electronic expansion valve 202 is located upstream of the evaporating part of the first economizer 20. In this way, part of the refrigerant flowing out of the condenser flows into the condensing part of the first economizer 20, and the other part flows into the evaporating part of the first economizer 20. The first electronic expansion valve 202 throttles and cools the refrigerant between the evaporating part of the first economizer 20. In this way, the refrigerant in the evaporating part of the first economizer 20 and the condensing part of the first economizer 20 can exchange heat, thereby reducing the temperature of the refrigerant flowing out of the condensing part of the first economizer 20 and providing the temperature of the refrigerant flowing out of the evaporating part of the first economizer 20. In this way, the condensing part of the first economizer 20 can further ensure the condensing temperature of the cold and heat unit, and the evaporating part of the first economizer 20 exchanges heat to become gaseous refrigerant.

[0047] Optionally, the cold and heat unit further comprises a second economizer 40, an outlet of the evaporating part of the first economizer 20 is communicated with an inlet of the second economizer 40, a second electronic expansion valve 401 is arranged at an upstream of the evaporating part of the second economizer 40, and an outlet of the evaporating part of the second economizer 40 is communicated with the middle-pressure cabin of the compressor 10. In this way, the gaseous refrigerant flowing out of the evaporating part of the second economizer 40 can flow to the middle-pressure cabin of the compressor 10 for supplement, thereby improving the operation efficiency of the cold and heat unit.

[0048] Optionally, an outlet of the first economizer 20 is communicated with the low-pressure cabin of the compressor 10, so that when the refrigerant flowing out of the first economizer 20 is completely evaporated into gaseous refrigerant, the low-pressure cabin can also be supplemented.

[0049] Optionally, the cold and heat unit further comprises a second bypass pipeline 402 and the second electronic expansion valve 401, an inlet of the second bypass pipeline 402 is communicated with an outlet of the evaporating part of the first economizer 20, and an outlet of the second bypass pipeline 402 is communicated with the middle-pressure cabin of the compressor 10. The evaporating part of the second economizer 40 and the second electronic expansion valve 401 are arranged in the second bypass pipeline 402, and the second electronic expansion valve 401 is arranged at an upstream of the evaporating part of the second economizer 40, so that the temperature of the refrigerant after the second electronic expansion valve 401 can be reduced.

[0050] Optionally, an inlet of the condensing part of the second economizer 40 is communicated with an outlet of the evaporating part of the first economizer 20, and an outlet of the condensing part of the second economizer 40 is communicated with the low-pressure cabin of the compressor 10, so that the condensing part of the second economizer 40 can exchange heat with the evaporating part of the second economizer 40, and the refrigerant flowing out of the first economizer 20 can be further evaporated in the evaporating part of the second economizer 40, so as to ensure that the refrigerant flowing to the compressor 10 from the second economizer 40 is completely gaseous refrigerant.

[0051] Optionally, the outlet of the evaporating part of the second economizer 40 can also be communicated with the low-pressure cabin of the compressor 10, so that the refrigerant flowing into the low-pressure cabin and the middle-pressure cabin of the compressor 10 can be gaseous refrigerant.

[0052] Optionally, the cold and heat unit further comprises a first branch 2071 and a second branch 2081, the first branch 2071 is communicated between the outlet of the evaporating part of the second economizer 40 and the middle-pressure cabin of the compressor 10, and the second branch 2081 is communicated between the outlet of the evaporating part of the first economizer 20 and the low-pressure cabin of the compressor 10. The cold and heat unit further comprises a first control valve 207 and a second control valve 208, the first control valve 207 is arranged in the first branch 2071 and is used to control the refrigerant flow of the first branch 2071, and the second control valve 208 is arranged in the second branch 2081 and is used to control the refrigerant flow of the second branch 2081.

[0053] In the embodiments of the present disclosure, the first branch 2071 can guide the gaseous refrigerant flowing out of the evaporating portion of the second economizer 40 into the medium-pressure cabin of the compressor 10, the second branch 2081 can guide the gaseous refrigerant flowing out of the evaporating portion of the first economizer 20 into the low-pressure cabin of the compressor 10, and each branch is provided with a control valve, so that the opening and closing of each branch is controllable.

[0054] Optionally, the cold-heat unit further comprises a gas-liquid separator 104, which is arranged between the outlet of the four-way valve 101 and the low-pressure cabin of the compressor 10. The refrigerant evaporated by the evaporator flows into the gas-liquid separator 104 through the four-way valve 101. After the refrigerant is separated in the gas-liquid separator 104, the gaseous refrigerant flows into the low-pressure cabin of the compressor 10 to realize the gas return of the compressor 10.

[0055] Optionally, the second branch 2081 is connected between the outlet of the evaporating portion of the first economizer 20 and the inlet of the gas-liquid separator 104, so that the refrigerant flowing out of the evaporating portion of the first economizer 20 can pass through the gas-liquid separator to ensure that the refrigerant flowing into the compressor 10 is in a gaseous state, thereby avoiding liquid strike caused by liquid refrigerant entering the compressor 10.

[0056] Optionally, the condensing portion of the second economizer 40 is arranged in the second branch 2081, the inlet of the condensing portion of the second economizer 40 is connected with the outlet of the evaporating portion of the first economizer 20, and the outlet of the condenser of the second economizer 40 is connected with the inlet of the gas-liquid separator 104.

[0057] Optionally, when the outlet of the evaporating portion of the second economizer 40 is connected with the low-pressure cabin of the compressor 10, the outlet of the evaporating portion of the second economizer 40 is connected with the inlet of the gas-liquid separator 104 through a third branch, and the third branch is provided with a third control valve for controlling the flow of the third branch.

[0058] Optionally, the cold-heat unit comprises a first temperature sensor 203 and a second temperature sensor 204. The first temperature sensor 203 is arranged at the inlet of the condensing portion of the first economizer 20 of the first economizer 20, and the second temperature sensor 204 is arranged at the outlet of the condensing portion of the first economizer 20 of the first economizer 20. The first temperature sensor 203 is used to detect the inlet refrigerant temperature of the condensing portion of the first economizer 20, and the second temperature sensor 204 is used to detect the outlet refrigerant temperature of the condensing portion of the first economizer 20.

[0059] Optionally, the cold-heat unit further comprises a high-pressure pressure sensor 107, which is arranged between the exhaust port of the compressor 10 and the four-way valve 101. The high-pressure pressure sensor 107 is used to detect the high-pressure of the cold-heat unit.

[0060] Optionally, the heat pump unit further comprises a low-pressure pressure sensor 108 of the heat pump unit, which is arranged between the gas-liquid separator 104 and the compressor 10, and is configured to detect a low-pressure pressure of the heat pump unit.

[0061] Optionally, the first control valve 207 is an electronic expansion valve 202 or a solenoid valve. Optionally, the second control valve 208 is an electronic expansion valve 202 or a solenoid valve.

[0062] Optionally, the heat pump unit comprises a third temperature sensor 205 and a fourth temperature sensor 206, the third temperature sensor 205 is arranged at an inlet of the evaporating part of the first economizer 20, and the fourth temperature sensor 206 is arranged at an outlet of the evaporating part of the first economizer 20, the third temperature sensor 205 is configured to detect an inlet refrigerant temperature of the evaporating part of the first economizer 20, and the fourth temperature sensor 206 is configured to detect an outlet refrigerant temperature of the evaporating part of the first economizer 20.

[0063] Optionally, the fourth temperature sensor 206 is capable of detecting the outlet refrigerant temperature of the evaporating part of the first economizer 20, and the outlet refrigerant temperature of the evaporating part of the first economizer 20 is also the inlet refrigerant temperature of the evaporating part of the second economizer 40.

[0064] Optionally, the heat pump unit further comprises a fifth temperature sensor 209, which is arranged at an outlet of the evaporating part of the second economizer 40, and is configured to detect an outlet refrigerant temperature of the evaporating part of the second economizer 40.

[0065] Optionally, the indoor heat exchanger 102 is a water-fluorine heat exchanger, a fluorine side of the water-fluorine heat exchanger is in communication with the compressor 10 and the outdoor heat exchanger 103, and a water side of the water-fluorine heat exchanger is in communication with a water heat exchange system, which can be a floor heating system or a water heater.

[0066] Optionally, the water-fluorine heat exchanger is a plate heat exchanger or a double-pipe heat exchanger.

[0067] Optionally, the heat pump unit further comprises a liquid storage tank 105, which is arranged between the throttling device and the condenser.

[0068] Optionally, the throttling device comprises a first throttling device 1061 and a second throttling device 1062, the first throttling device 1061 is arranged between the first economizer 20 and the indoor heat exchanger 102, and is configured to throttle the refrigerant flowing out of the first economizer 20 during refrigeration. The second throttling device 1062 is arranged between the first economizer 20 and the outdoor heat exchanger 103, and is configured to throttle the refrigerant flowing out of the first economizer 20 during heating.

[0069] Optionally, as shown in FIG. 1, the heat pump unit further comprises a first control valve 207 and a second control valve 208, the first control valve 207 is arranged between the first economizer 20 and the indoor heat exchanger 102, and is configured to control the flow of the refrigerant flowing out of the first economizer 20 during refrigeration. The second control valve 208 is arranged between the first economizer 20 and the outdoor heat exchanger 103, and is configured to control the flow of the refrigerant flowing out of the first economizer 20 during heating. Figure 2As shown, the embodiment of the present disclosure further provides a method for controlling a cold-heat unit, comprising:

[0070] S101, the processor acquires the outlet refrigerant temperature of the evaporating part of the first economizer.

[0071] S102, according to the outlet refrigerant temperature of the evaporating part of the first economizer, the processor confirms the evaporation condition of the refrigerant outlet of the evaporating part of the first economizer.

[0072] S103, according to the evaporation condition of the refrigerant outlet of the evaporating part of the first economizer, the processor controls the opening degree of the second electronic expansion valve.

[0073] Here, the refrigerant flowing out of the outlet of the evaporating part of the first economizer is the evaporated refrigerant, which is completely gaseous refrigerant or mixed refrigerant. According to the temperature of the outlet refrigerant of the evaporating part of the first economizer, it can be confirmed whether the refrigerant outlet of the evaporating part of the first economizer is completely evaporated. If the refrigerant of the evaporating part of the first economizer is not completely evaporated, the liquid refrigerant flowing into the compressor will cause the compressor to be liquid hit. Therefore, the refrigerant flowing out of the evaporating part of the first economizer is evaporated again by the evaporating part of the second economizer, and then the refrigerant flowing out of the evaporating part of the second economizer is ensured to be gaseous refrigerant. Here, by adjusting the opening degree of the second electronic expansion valve, the heat exchange effect of the second economizer can be adjusted to ensure that the refrigerant flowing out of the evaporating part of the second economizer is gaseous refrigerant.

[0074] Optionally, in step 102, when the outlet refrigerant temperature of the evaporating part of the first economizer is less than the evaporation temperature threshold, the processor confirms that the refrigerant outlet of the evaporating part of the first economizer is not completely evaporated; when the outlet refrigerant temperature of the evaporating part of the first economizer is greater than or equal to the evaporation temperature threshold, the processor confirms that the refrigerant outlet of the evaporating part of the first economizer is completely evaporated.

[0075] Here, according to the temperature of the outlet refrigerant of the evaporating part of the first economizer, the evaporation effect of the evaporating part of the first economizer is judged to determine whether the refrigerant outlet of the evaporating part of the first economizer is completely evaporated into gaseous refrigerant. When the temperature of the refrigerant outlet of the evaporating part of the first economizer is greater than or equal to the evaporation temperature threshold, it is confirmed that the outlet refrigerant of the evaporating part of the first economizer is completely evaporated. When the temperature of the refrigerant outlet of the evaporating part of the first economizer is less than the evaporation temperature threshold, it is confirmed that the outlet refrigerant of the evaporating part of the first economizer is not completely evaporated, which means that the refrigerant flowing out of the evaporating part is not completely gaseous refrigerant. At this time, the opening degree of the second electronic expansion valve is adjusted to ensure that the refrigerant is completely evaporated into gaseous refrigerant.

[0076] Optionally, the evaporation temperature threshold is determined according to the low-pressure pressure of the cold-heat unit.

[0077] Optionally, as Figure 3As shown, the embodiments of the present disclosure further provide a method for controlling a cold and heat unit, comprising:

[0078] S201, the processor acquires the outlet refrigerant temperature of the evaporating part of the first economizer.

[0079] S202, according to the outlet refrigerant temperature of the evaporating part of the first economizer, the processor confirms the evaporation condition of the refrigerant outlet of the evaporating part of the first economizer.

[0080] S203, in the case that the refrigerant outlet of the evaporating part of the first economizer is not completely evaporated, the processor controls the second electronic expansion valve to reduce the opening degree.

[0081] S204, in the case that the opening degree of the second electronic expansion valve is reduced to the second opening degree, and the real-time temperature of the outlet refrigerant of the evaporating part of the second economizer is less than the evaporation temperature threshold, the processor controls the second electronic expansion valve to reset and increase the opening degree until the outlet refrigerant temperature of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold.

[0082] Here, when the refrigerant outlet of the evaporating part of the second economizer is not completely evaporated, by controlling the second electronic expansion valve to reduce the opening degree, the flow of the refrigerant of the evaporating part of the second economizer is reduced, and the heat exchange effect between the evaporating part of the second economizer and the condensing part of the second economizer is improved, so as to adjust the temperature of the evaporating part of the second economizer and improve the evaporation effect, so that the refrigerant flowing out of the evaporating part is completely evaporated.

[0083] When the opening degree of the second electronic expansion valve is reduced to the second opening degree, and the outlet refrigerant temperature of the evaporating part is still lower than the evaporation temperature threshold, the electronic expansion valve is controlled to reset and increase the opening degree, which can increase the flow of the refrigerant entering the evaporating part, which is helpful to improve the evaporation effect of the refrigerant in the evaporating part.

[0084] Optionally, the processor controls the second electronic expansion valve to reset and increase the opening degree until the outlet refrigerant temperature of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold, and the opening degree of the second electronic expansion valve here is the opening degree before the second electronic expansion valve reduces the opening degree.

[0085] Optionally, the processor controls the second electronic expansion valve to reduce the opening degree, comprising that the processor controls the second electronic expansion valve to reduce the opening degree at a first preset speed. For example, the opening degree can be gradually reduced by 1 step, 2 steps or 3 steps per 10 seconds.

[0086] Optionally, the processor controls the second electronic expansion valve to reset and increase the opening degree, comprising that the processor controls the second electronic expansion valve to increase the opening degree at a second preset speed. For example, the opening degree can be gradually increased by 1 step, 2 steps or 3 steps per 10 seconds.

[0087] Optionally, in step S103, the processor controls the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporation section of the first economizer, including controlling the second electronic expansion valve to be closed or fully opened in the case that the refrigerant at the outlet of the evaporation section of the first economizer is completely evaporated.

[0088] In the embodiments of the present disclosure, the second electronic expansion valve is controlled to be fully opened or closed in the case that the refrigerant at the outlet of the evaporation section of the first economizer is completely evaporated, so that the evaporation section and the condensation section of the second economizer do not exchange heat, thereby ensuring that the refrigerant at the condensation section of the second economizer is in a gaseous state, and ensuring that the refrigerant flowing into the compressor from the condensation section of the second economizer is in a gaseous state.

[0089] Optionally, as shown in Figure 4 The embodiments of the present disclosure also provide a method for controlling a cold-heat unit, including:

[0090] S301, the processor acquires the outlet refrigerant temperature of the evaporation section of the first economizer.

[0091] S302, the processor confirms the evaporation condition of the refrigerant at the outlet of the evaporation section of the first economizer according to the outlet refrigerant temperature of the evaporation section of the first economizer.

[0092] S303, the processor controls the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporation section of the first economizer.

[0093] S304, after confirming that the outlet refrigerant temperature of the evaporation section of the second economizer is greater than or equal to the evaporation temperature threshold, the processor acquires the discharge temperature of the compressor or the low-pressure pressure of the cold-heat unit.

[0094] S305, the processor controls the opening degrees of the second electronic expansion valve, the first control valve and the second control valve according to the discharge temperature of the compressor or the low-pressure pressure of the cold-heat unit.

[0095] Here, in the case that the evaporation section is completely evaporated, the refrigerant flowing out of the evaporation section is completely in a gaseous state, and according to the discharge temperature of the compressor or the low-pressure pressure of the cold-heat unit, the opening degrees of the second electronic expansion valve, the first control valve and the second control valve are selected to be controlled, so that the gaseous refrigerant can be supplemented into the medium-pressure cabin or the low-pressure cabin of the compressor as needed.

[0096] Optionally, as shown in Figure 5 The embodiments of the present disclosure also provide another method for controlling a cold-heat unit, including:

[0097] S401, the processor acquires the outlet refrigerant temperature of the evaporation section of the first economizer.

[0098] S402, according to the first economizer evaporator outlet refrigerant temperature, the processor confirms the first economizer evaporator outlet refrigerant evaporation.

[0099] S403, according to the first economizer evaporator outlet refrigerant evaporation, the processor controls the second electronic expansion valve opening.

[0100] S404, in the case of confirming the second economizer evaporator outlet refrigerant temperature is greater than or equal to the evaporation temperature threshold, the processor obtains the compressor discharge temperature or low pressure of the heat pump unit.

[0101] S405, in the case of the compressor discharge temperature is greater than or equal to the preset temperature, the processor controls the second electronic expansion valve to keep the opening, and controls the first control valve to open and the second control valve to close.

[0102] S406, in the case of the low pressure of the heat pump unit is less than or equal to the preset pressure, the processor controls the second electronic expansion valve to open or close, and controls the second control valve to open.

[0103] In the embodiment of the present disclosure, when the heat pump unit is refrigerating or heating, when the discharge temperature of the compressor is too high, the system and the compressor and the electrical control parts are damaged, too high temperature will carbonize the compressor lubricating oil and damage the compressor. At this time, when the heat pump unit is refrigerating, the processor controls the second electronic expansion valve to keep the opening, so as to ensure that the refrigerant flowing out of the second economizer evaporator is gaseous refrigerant, and the first control valve is opened and the second control valve is closed. In this way, the gaseous refrigerant flowing out of the second economizer evaporator is supplemented to the medium pressure cabin of the compressor through the first branch, and the gas supplement is reduced to reduce the refrigerant temperature in the compressor, which increases the supercooling degree of the refrigerant in the compressor, effectively reduces the discharge temperature, and enables the compressor to operate at a higher frequency, increases the speed, increases the discharge capacity of the refrigerant secondary compression, increases the refrigerating capacity, and prevents the discharge from overheating. When the heat pump unit is heating, the temperature of the compressor is too high, and the first branch is supplemented with gas, which can also reduce the discharge temperature, compress the refrigerant, prevent the discharge from overheating, reduce the compressor, protect the system safety, and improve the heating capacity.

[0104] Similarly, when the low-pressure sensor detects that the low-pressure of the heat pump unit is less than or equal to the preset pressure, it indicates that the outdoor heat exchanger is frosting, and the capacity is reduced. At this time, the second electronic expansion valve is fully opened or closed, so that the temperature of the condensing part of the second economizer will not be reduced, to ensure that the content of gaseous refrigerant flowing out of the condensing part of the second economizer. The refrigerant of the second branch will flow into the gas-liquid separator for gas-liquid separation, so that the gaseous refrigerant flowing into the low-pressure cabin of the compressor can be ensured, and the gaseous refrigerant can be supplemented through the second control valve to increase the enthalpy, improve the low-pressure of the heat pump unit, slow down the frosting of the outdoor heat exchanger, and improve the heating capacity of the heat pump unit. In this way, the gas supplement during refrigeration and heating can be considered at the same time, the operating efficiency is improved, and the safety and stability of the heat pump unit are ensured.

[0105] Optionally, the opening degree of the first control valve is proportional to the amount of gas supplement required by the medium-pressure cabin of the compressor. The greater the opening degree of the first control valve, the greater the amount of gas supplement required by the medium-pressure cabin of the compressor. The smaller the opening degree of the first control valve, the smaller the amount of gas supplement required by the medium-pressure cabin of the compressor.

[0106] Optionally, the amount of gas supplement required by the medium-pressure cabin of the compressor is determined according to the exhaust temperature of the compressor. The higher the exhaust temperature, the greater the amount of gas supplement required by the medium-pressure cabin of the compressor, and the greater the opening degree of the first control valve.

[0107] Optionally, the opening degree of the second control valve is proportional to the amount of gas supplement required by the low-pressure cabin of the compressor. The greater the opening degree of the second control valve, the greater the amount of gas supplement required by the low-pressure cabin of the compressor. The smaller the opening degree of the second control valve, the smaller the amount of gas supplement required by the low-pressure cabin of the compressor.

[0108] Optionally, when the second control valve is opened, the first control valve can be closed or opened. Since the second branch is in communication with the low-pressure cabin of the compressor, the pressure of the second branch is lower than that of the first branch. Therefore, whether the first control valve is opened or not, the gaseous refrigerant of the evaporating part of the second economizer will flow into the low-pressure cabin of the compressor through the second branch when the second control valve is opened.

[0109] Optionally, when the heat pump unit includes a third control valve, after controlling the opening degree of the second electronic expansion valve according to the evaporation of the refrigerant at the outlet of the evaporating part of the first economizer, the method for controlling the heat pump unit further includes: after confirming that the refrigerant at the outlet of the evaporating part of the second economizer is completely evaporated, the processor acquires the exhaust temperature of the compressor or the low-pressure of the heat pump unit; and according to the exhaust temperature of the compressor or the low-pressure of the heat pump unit, the processor controls the opening degrees of the second electronic expansion valve, the first control valve, and the third control valve.

[0110] Optionally, in the case that the low-pressure pressure of the cold and heat unit is less than or equal to the preset pressure, the second electronic expansion valve is controlled to keep the opening degree, and the third control valve is controlled to open, so that the evaporated refrigerant of the evaporating part of the second economizer can flow to the gas-liquid separator and then flow into the low-pressure cabin of the compressor for air supplement and enthalpy increase.

[0111] Optionally, in the case that the discharge temperature of the compressor is greater than or equal to the preset temperature, the second electronic expansion valve is controlled to keep the opening degree, and the first control valve is controlled to open and the third control valve is controlled to close, so that the gaseous refrigerant of the evaporating part of the second economizer can flow into the medium-pressure cabin of the compressor, avoiding being sucked into the low-pressure cabin of the compressor by the third branch.

[0112] Optionally, as shown in Figure 6 the disclosure also provides another method for controlling a cold and heat unit, comprising:

[0113] S501, the processor acquires the inlet refrigerant temperature and outlet refrigerant temperature of the condensing part of the first economizer.

[0114] S502, according to the inlet refrigerant temperature and outlet refrigerant temperature of the condensing part of the first economizer, the processor controls the opening degree of the first electronic expansion valve until the outlet refrigerant temperature of the condensing part of the first economizer is less than or equal to the condensing temperature threshold.

[0115] S503, the processor acquires the outlet refrigerant temperature of the evaporating part of the first economizer.

[0116] S504, according to the outlet refrigerant temperature of the evaporating part of the first economizer, the processor confirms the evaporation condition of the refrigerant exported by the evaporating part of the first economizer.

[0117] S505, according to the evaporation condition of the refrigerant exported by the evaporating part of the first economizer, the processor controls the opening degree of the second electronic expansion valve.

[0118] Here, the cold and heat unit dissipates heat through the condenser, the condensing part of the first economizer is located downstream of the condenser, and the evaporation condition of the refrigerant of the condenser can be judged by acquiring the inlet refrigerant temperature of the condensing part of the first economizer. When the condensation of the condenser is incomplete, the first electronic expansion valve adjusts the opening degree to make the condensing part of the first economizer exchange heat with the evaporating part of the first economizer, further reducing the temperature of the refrigerant, but when the outlet refrigerant temperature of the condensing part of the first economizer is less than or equal to the condensing temperature threshold, it can be proved that the refrigerant exported by the condensing part of the first economizer is completely condensed, which can improve the working efficiency of the cold and heat unit and ensure the refrigeration or heating effect.

[0119] Optionally, the condensing temperature threshold is determined according to the pressure detected by the high-pressure pressure sensor. Here, the high-pressure pressure sensor can detect the discharge pressure of the compressor, and the condensing temperature threshold of the refrigerant flowing out of the condenser of the cold and heat unit can be calculated, which is the condensing temperature ensuring normal operation of the cold and heat unit.

[0120] Optionally, as shown in FIG. 1, the embodiment of the present disclosure also provides another method for controlling a cold and heat unit, comprising: Figure 7

[0121] S601, the processor acquires the inlet refrigerant temperature and outlet refrigerant temperature of the condensing part of the first economizer.

[0122] S602, in the case that the inlet refrigerant temperature of the condensing part of the first economizer is greater than the condensing temperature threshold, the processor controls the first electronic expansion valve to reduce the opening degree.

[0123] S603, in the case that the opening degree of the electronic expansion valve is reduced to the first opening degree, and the outlet real-time refrigerant temperature of the condensing part of the first economizer is greater than or equal to the condensing temperature threshold, the processor controls the first electronic expansion valve to reset and increase the opening degree until the outlet refrigerant temperature of the condensing part of the first economizer is less than or equal to the condensing temperature threshold.

[0124] S604, the processor acquires the outlet refrigerant temperature of the evaporating part of the first economizer.

[0125] S605, according to the outlet refrigerant temperature of the evaporating part of the first economizer, the processor confirms the evaporation condition of the refrigerant exported by the evaporating part of the first economizer.

[0126] S606, according to the evaporation condition of the refrigerant exported by the evaporating part of the first economizer, the processor controls the opening degree of the second electronic expansion valve.

[0127] In the embodiment of the present disclosure, when the refrigerant condensing of the condenser is not complete, the processor controls the first electronic expansion valve to reduce the opening degree to reduce the temperature of the evaporating part, and thus improve the condensing effect of the condensing part of the first economizer. When the opening degree of the first electronic expansion valve is reduced to the first opening degree, but the outlet refrigerant temperature of the condensing part of the first economizer is still high, it indicates that the refrigerant of the condensing part of the first economizer is still not complete, at this time, the first electronic expansion valve is controlled to reset, and then the opening degree of the first electronic expansion valve is increased, which can improve the flow of the evaporating part of the first economizer, so that the first electronic expansion valve still has the throttling effect, but the refrigerant flow of the evaporating part of the first economizer is increased, and the refrigerant flow for heat exchange with the condensing part of the first economizer is also increased, so that the heat dissipation effect of the condensing part of the first economizer is improved, and the temperature of the evaporating part after the first electronic expansion valve is less than the temperature of the condensing part of the first economizer, which can reduce the temperature of the condensing part of the first economizer and improve the condensing effect. ​

[0128] Optionally, the processor controls the first electronic expansion valve to reset and increase the opening degree, wherein the reset refers to the opening degree before the first electronic expansion valve decreases the opening degree.

[0129] Optionally, the condensing temperature threshold is determined according to the high-pressure of the heat pump unit.

[0130] Optionally, the processor controls the first electronic expansion valve to decrease the opening degree, including that the processor controls the first electronic expansion valve to decrease the opening degree at a third preset speed. For example, the opening degree can be gradually decreased by 1 step, 2 steps or 3 steps per 10 seconds.

[0131] Optionally, the processor controls the first electronic expansion valve to reset and increase the opening degree, including that the processor controls the first electronic expansion valve to increase the opening degree at a fourth preset speed. For example, the opening degree can be gradually increased by 1 step, 2 steps or 3 steps per 10 seconds.

[0132] Optionally, as shown in FIG. 8, the embodiment of the present disclosure further provides another method for controlling a heat pump unit, including: Figure 8

[0133] S701, the processor acquires the outlet refrigerant temperature of the evaporating part of the first economizer.

[0134] S702, according to the outlet refrigerant temperature of the evaporating part of the first economizer, the processor confirms the evaporation condition of the refrigerant outlet of the evaporating part of the first economizer.

[0135] S703, according to the evaporation condition of the refrigerant outlet of the evaporating part of the first economizer, the processor controls the opening degree of the second electronic expansion valve.

[0136] S704, in the case that the outlet refrigerant temperature of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold, the processor acquires the high-pressure and low-pressure of the heat pump unit.

[0137] S705, according to the high-pressure and low-pressure of the heat pump unit, the processor confirms the compression ratio of the heat pump unit.

[0138] S706, in the case that the compression ratio of the heat pump unit is greater than the optimal compression ratio, the processor controls the second electronic expansion valve to keep the opening degree, and controls the first control valve to open and the second control valve to close.

[0139] S706, in the case that the high-pressure of the heat pump unit is less than the pressure threshold, the processor controls the second control valve to open until the compressor of the heat pump unit reaches the optimal compression ratio.

[0140] ​Here, when the compression ratio of the chiller unit is greater than its optimal compression ratio, the second electronic expansion valve is kept open to ensure complete evaporation of the refrigerant at the evaporator outlet of the second economizer. The first control valve is opened, and the second control valve is closed to replenish gas to the compressor's intermediate-pressure compartment. If the high-pressure pressure is too low after replenishment, this will lead to an excessively low compression ratio. Therefore, the second control valve is opened to increase the low-pressure pressure and decrease the high-pressure pressure, thereby increasing the compression ratio to maintain it at the optimal level.

[0141] Here, compression ratio refers to the ratio of high pressure to low pressure.

[0142] Optionally, the optimal compression ratio is determined based on the design parameters of the compressors from different manufacturers and series. The optimal compression ratio can be a single value or a range of values.

[0143] like Figure 1 As shown, in some optional embodiments, when the cooling unit is cooling, the outdoor heat exchanger is a condenser and the indoor heat exchanger is an evaporator. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows into the condenser through the four-way valve D pipe and out through the C pipe. After being condensed by the condenser, the liquid refrigerant is subcooled through the condenser section of the first economizer. At this time, the opening of the first electronic expansion valve is adjusted according to the temperature detected by the first temperature sensor and the second temperature sensor, so that the refrigerant flowing out of the first economizer is completely condensed. The condensed refrigerant flows through the liquid storage tank, passes through the throttling device and enters the water-fluorine heat exchanger for heat exchange and cooling. At the same time, the fourth temperature sensor determines whether the refrigerant discharged from the evaporator section of the first economizer has been completely evaporated. If the refrigerant discharged from the evaporator section of the first economizer has not been completely evaporated, the opening of the second electronic expansion valve is controlled so that the refrigerant flowing out of the evaporator section of the second economizer is completely evaporated. The opening degrees of the second electronic expansion valve, the first control valve, and the second control valve are adjusted according to the detected exhaust temperature. When the exhaust temperature is too high, the second electronic expansion valve is kept open, the first control valve is opened, and the second control valve is closed to ensure that the gaseous refrigerant flowing out of the evaporator of the second economizer can flow into the compressor intermediate pressure chamber to cool the refrigerant in the intermediate pressure chamber, so that the refrigerant can be compressed twice to improve operating efficiency. It can also effectively prevent a large amount of liquid refrigerant from entering the compressor and causing liquid slugging.

[0144] When the heat pump unit is heating, the four-way valve is powered on, and the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows into the E pipe from the D pipe of the four-way valve and then flows out into the water-fluorine heat exchanger. The liquid refrigerant flowing out of the water-fluorine heat exchanger passes through the first economizer. According to the fourth temperature sensor, it is determined whether the refrigerant flowing out of the evaporation part of the first economizer is completely evaporated. If the refrigerant flowing out of the evaporation part of the first economizer is not completely evaporated, the opening degree of the second electronic expansion valve is controlled to make the refrigerant flowing out of the evaporation part of the second economizer completely evaporated. The opening degrees of the second electronic expansion valve, the first control valve and the second control valve are adjusted according to the detected exhaust temperature at this time. When the exhaust temperature is too high, the second electronic expansion valve is controlled to keep the opening degree, the first control valve is controlled to open, and the second control valve is controlled to close, so as to ensure that the gaseous refrigerant flowing out of the evaporation part of the second economizer can flow into the compression chamber of the compressor, cool the refrigerant in the compression chamber of the compressor, make the refrigerant be compressed twice, improve the operation efficiency, and effectively prevent a large amount of liquid refrigerant from entering the compressor to cause liquid strike. At the same time, when the low-pressure pressure of the heat pump unit is lower than the preset pressure, the second electronic expansion valve is controlled to be fully opened or closed, and the second control valve is controlled to be opened, so as to supplement the air of the system, slow down the frosting speed of the condenser, and improve the heating capacity.

[0145] In combination with Figure 9 As shown in FIG. 9, the embodiment of the present disclosure provides a device 90 for controlling a heat pump unit, which comprises a processor 900 and a memory 901. Optionally, the device 90 can further comprise a communication interface 902 and a bus 903. The processor 900, the communication interface 902 and the memory 901 can complete mutual communication through the bus 903. The communication interface 902 can be used for information transmission. The processor 900 can invoke the logical instructions in the memory 901 to execute the method for controlling a heat pump unit in the above embodiment.

[0146] In addition, the logical instructions in the memory 901 described above can be implemented in the form of a software functional unit and sold or used as an independent product, which can be stored in a computer readable storage medium.

[0147] The memory 901 is a computer readable storage medium, which can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 900 executes the program instructions / modules stored in the memory 901, thereby performing functional applications and data processing, that is, implementing the method for controlling a heat pump unit in the above embodiment.

[0148] The memory 901 can include a program storage area and a data storage area, where the program storage area can store an operating system, application programs required by at least one function; and the data storage area can store data created according to the use of the terminal device, and the like. In addition, the memory 901 can include a high-speed random access memory, and can also include a nonvolatile memory.

[0149] The embodiment of the present disclosure provides a cold and heat unit, which comprises a cold and heat unit body and the device 90 for controlling the cold and heat unit. The cold and heat unit body comprises the refrigerant circulation loop, the refrigerant circulation loop comprises a compressor, a four-way valve, a condenser, a throttling device and an evaporator, high-temperature and high-pressure refrigerant flowing out of the compressor flows into the condenser through the four-way valve, and after heat dissipation in the condenser, the refrigerant flows into the throttling device for throttling. The throttled refrigerant becomes low-pressure refrigerant and flows into the evaporator. The refrigerant in the evaporator is evaporated to become gaseous refrigerant, and then flows into the compressor. The device 90 for controlling the cold and heat unit is installed on the cold and heat unit body. The installation relationship described herein is not limited to being placed in the cold and heat unit, but also includes installation connection with other components of the cold and heat unit, including but not limited to physical connection, electrical connection or signal transmission connection, etc. Those skilled in the art can understand that the device 90 for controlling the cold and heat unit can be adapted to the feasible cold and heat unit body, and thus realize other feasible embodiments.

[0150] The embodiment of the present disclosure provides a computer readable storage medium, which stores computer executable instructions, and the computer executable instructions are set to execute the method for controlling the cold and heat unit.

[0151] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes one or more instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium can be a non-transitory storage medium, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0152] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0153] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0154] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to apparatuses, devices, etc.), can be implemented in other manners. For example, the described apparatus embodiments can be implemented only in a form of a logical function, and can be implemented by using a manner such as software (for example, application program) or the like. In some embodiments, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or indirect coupling between different units, or the coupling or direct coupling or indirect coupling between the displayed or discussed communication connections can be in a form of electrical, mechanical or other forms.

[0155] The flowcharts and block diagrams in the drawings show the possible implementation architectures, functions and operations of the system, method and computer program product according to the embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment or a part of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions noted in the blocks can occur in an order different from that noted in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the drawings, the operations or steps corresponding to different blocks can also occur in an order different from that disclosed in the descriptions, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. Each block in the block diagrams and / or flowcharts, and the combination of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling a chiller-heater unit, characterized by, The cold and heat unit comprises a compressor, a condenser, an evaporator, a first economizer and a second economizer, a condensing part of the first economizer is communicated between the condenser and a throttling device, an inlet of an evaporating part of the first economizer is communicated with an outlet of the condenser, an evaporating part of the second economizer and an inlet of a condensing part of the second economizer are both communicated with an outlet of the evaporating part of the first economizer; a second electronic expansion valve is arranged at an upstream of the evaporating part of the second economizer, an outlet of the evaporating part of the second economizer is communicated with a medium-pressure cabin of the compressor, the outlet of the evaporating part of the first economizer and / or the outlet of the evaporating part of the second economizer is communicated with a low-pressure cabin of the compressor, when the cold and heat unit is used for heating, the indoor heat exchanger is the condenser and the outdoor heat exchanger is the evaporator, when the cold and heat unit is used for refrigeration, the indoor heat exchanger is the evaporator and the outdoor heat exchanger is the condenser; the method comprises: acquiring an outlet refrigerant temperature of the evaporating part of the first economizer; confirming an evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer according to the outlet refrigerant temperature of the evaporating part of the first economizer; controlling an opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer.

2. The method of claim 1, wherein, The confirming of the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer according to the outlet refrigerant temperature of the evaporating part of the first economizer comprises: when the outlet refrigerant temperature of the evaporating part of the first economizer is less than an evaporation temperature threshold, confirming that the refrigerant at the outlet of the evaporating part of the first economizer is not completely evaporated; when the outlet refrigerant temperature of the evaporating part of the first economizer is greater than or equal to the evaporation temperature threshold, confirming that the refrigerant at the outlet of the evaporating part of the first economizer is completely evaporated.

3. The method of claim 2, wherein, The controlling of the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporating part of the first economizer comprises: when the refrigerant at the outlet of the evaporating part of the first economizer is not completely evaporated, controlling the second electronic expansion valve to reduce the opening degree; when the opening degree of the second electronic expansion valve is reduced to a second opening degree and a real-time temperature of the refrigerant at the outlet of the evaporating part of the second economizer is less than the evaporation temperature threshold, controlling the second electronic expansion valve to reset and increase the opening degree until the outlet refrigerant temperature of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold.

4. The method of claim 3, wherein, The cold and heat unit further comprises a gas-liquid separator, a first branch and a second branch, the first branch is communicated between the outlet of the evaporating part of the second economizer and the medium-pressure cabin of the compressor, the second branch is communicated between the outlet of the evaporating part of the first economizer and the inlet of the gas-liquid separator, the first branch is provided with a first control valve, the second branch is provided with a second control valve, the condensing part of the second economizer is arranged in the second branch, after the outlet refrigerant temperature of the evaporating part of the second economizer is greater than or equal to the evaporation temperature threshold, the method further comprises: acquiring an exhaust temperature of the compressor or a low-pressure pressure of the cold and heat unit; controlling the opening degrees of the second electronic expansion valve, the first control valve and the second control valve according to the exhaust temperature of the compressor or the low-pressure pressure of the cold and heat unit.

5. The method of claim 4, wherein, The controlling of the opening degrees of the second electronic expansion valve, the first control valve and the second control valve according to the exhaust temperature of the compressor or the low-pressure pressure of the cold and heat unit comprises: In a case that the low-pressure pressure of the cold heat unit is less than or equal to a preset pressure, the second electronic expansion valve is controlled to be fully opened or closed, and the second control valve is controlled to be opened; or In a case that the discharge temperature of the compressor is greater than or equal to a preset temperature, the second electronic expansion valve is controlled to maintain the opening degree, and the first control valve is controlled to be opened and the second control valve is controlled to be closed.

6. The method of claim 4, wherein, After the processor controls the opening degree of the second electronic expansion valve according to the evaporation condition of the refrigerant at the outlet of the evaporation part of the first economizer, the method further comprises: In a case that the outlet refrigerant temperature of the evaporation part of the second economizer is greater than or equal to an evaporation temperature threshold, the high-pressure pressure and the low-pressure pressure of the cold heat unit are obtained; According to the high-pressure pressure and the low-pressure pressure of the cold heat unit, the compression ratio of the cold heat unit is determined; In a case that the compression ratio of the cold heat unit is greater than an optimal compression ratio, the processor controls the second electronic expansion valve to maintain the opening degree, and controls the first control valve to be opened and the second control valve to be closed; In a case that the high-pressure pressure of the cold heat unit is less than a pressure threshold, the second control valve is controlled to be opened until the compressor of the cold heat unit reaches the optimal compression ratio.

7. The method according to any one of claims 1 to 6, characterized in that, Before the outlet refrigerant temperature of the evaporation part of the first economizer is obtained, the method further comprises: The inlet refrigerant temperature and the outlet refrigerant temperature of the condensing part of the first economizer are obtained; According to the inlet refrigerant temperature and the outlet refrigerant temperature of the condensing part of the first economizer, the opening degree of the first electronic expansion valve is controlled until the outlet refrigerant temperature of the condensing part of the first economizer is less than or equal to a condensing temperature threshold.

8. An apparatus for controlling a chiller-heater unit, characterized by, The device for controlling a cold heat unit comprises a processor and a memory storing program instructions, wherein the processor is configured to execute the method for controlling a cold heat unit according to any one of claims 1 to 7 when running the program instructions.

9. A chiller unit characterized by, The device for controlling a cold heat unit comprises: A refrigerant circulation loop comprising a compressor, a four-way valve, a condenser, a throttling device and an evaporator; A first economizer, a condensing part of the first economizer being communicated between the condenser and the throttling device, and an inlet of an evaporation part of the first economizer being communicated with an outlet of the condenser; A first electronic expansion valve, being communicated with the evaporation part of the first economizer and being located upstream of the evaporation part of the first economizer; A second economizer, an evaporation part of the second economizer and an inlet of a condensing part of the second economizer being both communicated with an outlet of the evaporation part of the first economizer; A second electronic expansion valve, being communicated with the evaporation part of the second economizer and being located upstream of the evaporation part of the second economizer; The device for controlling a cold heat unit according to claim 8.

10. The chiller unit of claim 9, wherein, The device for controlling a cold heat unit further comprises: A gas-liquid separator, a gas outlet of the gas-liquid separator being communicated with a low-pressure cabin of the compressor; A first branch, being communicated between the outlet of the evaporation part of the first economizer and the inlet of the gas-liquid separator; A second branch, being communicated between the outlet of the evaporation part of the second economizer and a medium-pressure cabin of the compressor; A first control valve, being arranged in the first branch and being used for controlling the refrigerant flow of the first branch; A second control valve, being arranged in the second branch and being used for controlling the refrigerant flow of the second branch.

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