Triple co-generation system and control method thereof

Abstract

The invention relates to the technical field of triple co-generation systems, in particular to a triple co-generation system and a control method thereof, and aims to solve the problem that an existing triple co-generation system is low in domestic water heating efficiency during heating in winter. In order to achieve the purpose, the triple co-generation system comprises a compressor, a first sub-waterway, a first refrigerant pipeline, a first heat exchanger, an evaporator and a water tank, the first sub-waterway is divided into a first branch waterway and a second branch waterway after passing through the first heat exchanger, and the first branch waterway communicates with a first water inlet of the water tank; the first branch water path is communicated with the first heat exchanger and used for injecting water subjected to heat exchange through the first heat exchanger into the water tank, the second branch water path is communicated with tail end heat dissipation equipment and used for dissipating heat indoors, an eighth valve is arranged between the first heat exchanger and the tail end heat dissipation equipment and is in communication connection with a controller of the triple co-generation system, and the water tank further comprises a water outlet used for providing domestic water. According to the triple co-generation system, hot water is provided through the water tank while heat is supplied through the tail end heat dissipation equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of trigeneration systems, and specifically provides a trigeneration system and a control method thereof. Background Art

[0002] The heat pump dual-generation system can meet the basic survival needs of users for warmth in winter and coolness in summer, but it cannot directly provide domestic hot water, and there is still a lot of room for improvement in user experience. The air conditioning trigeneration system uses a set of devices to achieve the three functions of hot water production, air conditioning heating and air conditioning cooling. At present, such air conditioning trigeneration systems have gradually become popular, but in actual use, it is found that the functions of such equipment are still relatively simple, the user experience is relatively poor in comfort and rationality, and it is unable to provide more reasonable and comfortable services according to the actual usage scenarios of users.

[0003] Chinese patent CN117663522A discloses a trigeneration system and its control method, which realizes the production of domestic hot water during both air conditioning cooling and heating through a compressor, a four-way valve, a gas-liquid separator, an air-side heat exchanger, a water-side heat exchanger and a water tank heat exchanger. However, domestic hot water and air conditioning hot and cold water are independent of each other, and the heating efficiency of domestic water is low and the temperature rises slowly during winter heating, resulting in poor user experience. Therefore, how to improve the heating efficiency of domestic water in the trigeneration system during winter heating has become a technical problem to be solved in this field.

[0004] In view of this, the art needs a new trigeneration system and a control method thereof to solve the existing problems. Summary of the invention

[0005] The present invention aims to solve the above technical problem, that is, to solve the problem that the existing trigeneration system has low heating efficiency for domestic water during winter heating.

[0006] In a first aspect, the present invention provides a trigeneration system, the trigeneration system comprising: a compressor connected to a refrigerant pipeline for compressing and circulating the refrigerant; a water circuit comprising a first water circuit, the first water circuit being connected to a water source, the first water circuit comprising a first sub-water circuit, the first sub-water circuit being provided with a first valve, the first valve being communicatively connected to a controller of the trigeneration system; a refrigerant pipeline comprising a first refrigerant pipeline; a first heat exchanger connected to an exhaust end of the compressor through the first refrigerant pipeline and also connected to the first sub-water circuit for realizing heat exchange between the refrigerant and water, the first valve being provided between the water source and the first heat exchanger; an evaporator a water tank, wherein the first sub-water channel is divided into a first branch water channel and a second branch water channel after passing through the first heat exchanger, the first branch water channel is connected to the first water inlet of the water tank, and is used to inject water after heat exchange by the first heat exchanger into the water tank, the second branch water channel is connected to the terminal heat dissipation device, and is used to dissipate heat to the room, an eighth valve is provided between the first heat exchanger and the terminal heat dissipation device, and the eighth valve is communicatively connected to the controller of the trigeneration system, and the water tank also includes a water outlet for providing domestic water.

[0007] In a specific embodiment of the above-mentioned trigeneration system, the water tank also includes a second water inlet, and the corresponding water path also includes a second water path, the second water path is connected to a water source and the second water inlet of the water tank, a second valve is provided on the first branch water path, and a third valve is provided on the second water path, the second valve and the third valve are both communicatively connected to the controller of the trigeneration system, and the water temperature in the water tank can be adjusted by controlling the opening and closing of the first valve, the second valve and the third valve.

[0008] In a specific embodiment of the above-mentioned trigeneration system, the first water circuit also includes a second sub-water circuit, the trigeneration system also includes a second heat exchanger, the refrigerant pipeline also includes a second refrigerant pipeline, the two ends of the second heat exchanger are respectively connected to the exhaust end and the intake end of the compressor through the second refrigerant pipeline, and the second heat exchanger is also connected to the second sub-water circuit for realizing heat exchange between the refrigerant and water, the second sub-water circuit is connected to the third water inlet of the water tank after passing through the second heat exchanger, a fourth valve and a fifth valve are arranged on the second sub-water circuit, the fourth valve is arranged between the water source and the second heat exchanger, the fifth valve is arranged between the second heat exchanger and the third water inlet of the water tank, a sixth valve and a seventh valve are arranged on the second refrigerant pipeline, the sixth valve is arranged between the exhaust end of the compressor and the second heat exchanger, the seventh valve is arranged between the second heat exchanger and the intake end of the compressor, and the fourth valve, the fifth valve, the sixth valve and the seventh valve are all communicatively connected to the controller of the trigeneration system.

[0009] The present invention also provides a control method for a trigeneration system, wherein the trigeneration system is the trigeneration system described in any one of the above technical solutions, and the control method comprises: obtaining control instructions for the trigeneration system; and controlling valves based on the obtained control instructions to determine whether the trigeneration system is cooling, heating, and supplying hot water.

[0010] In a specific implementation of the control method for the above-mentioned trigeneration system, the step of "controlling the valves based on the acquired control instructions as to whether the trigeneration system is cooling, heating, and supplying hot water" further includes: if the trigeneration system is required to heat and supply hot water, the fourth valve, the fifth valve, the sixth valve, and the seventh valve are controlled to be closed, and the first valve, the second valve, the third valve, and the eighth valve are controlled to be opened.

[0011] In a specific implementation of the control method for the above-mentioned trigeneration system, the step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating, and supplying hot water" further includes: if the trigeneration system is required to provide heating but not hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, and the seventh valve are controlled to be closed, and the first valve and the eighth valve are controlled to be opened.

[0012] In a specific implementation of the control method for the above-mentioned trigeneration system, the step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating, and supplying hot water" further includes: if the trigeneration system is required to cool and supply hot water, the first valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve, and the eighth valve are controlled to be opened, and the second valve is controlled to be closed.

[0013] In a specific implementation of the control method for the above-mentioned trigeneration system, the step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating, and supplying hot water" further includes: if the trigeneration system is required to cool but not supply hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, and the seventh valve are controlled to be closed, and the first valve and the eighth valve are controlled to be opened.

[0014] In a specific implementation of the control method for the above-mentioned trigeneration system, the trigeneration system also includes a temperature sensor, which is used to obtain the outlet water temperature of the first heat exchanger and the second heat exchanger, and the temperature sensor is communicatively connected to the controller of the trigeneration system, and the control method also includes: controlling the temperature sensor to obtain the outlet water temperature T2 of the first heat exchanger or the second heat exchanger; obtaining the set temperature T1 of the water tank; calculating the difference A between T1 and T2; comparing the difference A between T1 and T2 with the first preset difference B and the second preset difference C; adjusting the operating frequency of the compressor based on the comparison result; if A>B, controlling the compressor to increase the frequency according to the preset value; if A<C, controlling the compressor to decrease the frequency according to the preset value; if C≤A≤B, the compressor frequency maintains the original state.

[0015] In a specific implementation of the control method of the trigeneration system, the step of "calculating the difference A between T1 and T2" also includes: comparing the difference A between T1 and T2 with the third preset difference D and the fourth preset difference E; if A≥D, controlling the compressor to restart after a first time; if A≤E, controlling the compressor to stop after a first time.

[0016] The technical effect of the present invention is as follows: when the trigeneration system is required to provide heating and hot water at the same time, since the first heat exchanger is provided and the first heat exchanger is connected to the first sub-water channel and the first refrigerant pipeline, the high-temperature and high-pressure refrigerant discharged from the compressor can heat the water passing through the first heat exchanger. The heated water flows along the first sub-water channel and is divided into two parts. One part enters the water tank along the first branch water channel to provide domestic water for users, and the other part flows along the second branch water channel to the terminal heat dissipation device to provide indoor heating for users. Therefore, the trigeneration system of the present invention can achieve rapid heating of water while providing indoor heating, solving the problem of low heating efficiency of domestic water in the existing trigeneration system during winter heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0018] Figure 1 is a schematic diagram of a trigeneration system of the present invention;

[0019] Figure 2 It is a main flow chart of the control method of the trigeneration system of the present invention;

[0020] Figure 3 is a flow chart of step S2 in the second embodiment of the control method of the trigeneration system of the present invention;

[0021] Figure 4 is a main flow chart of the third embodiment of the control method of the trigeneration system of the present invention;

[0022] Figure 5 It is a flow chart of step S8 in the third embodiment of the control method of the trigeneration system of the present invention.

[0023] List of reference numerals:

[0024] 1-Trigeneration system; 11-compressor; 12-first water circuit; 121-first sub-water circuit; 1211-first branch water circuit; 12111-second valve; 1212-second branch water circuit; 1213-first valve; 1214-eighth valve; 122-second sub-water circuit; 1221-fourth valve; 1222-fifth valve; 13-first refrigerant pipeline; 131-four-way valve; 14-first heat exchanger; 15-evaporator; 16-water tank; 161-water outlet; 162-first water inlet; 163-second water inlet; 164-third water inlet; 17-second water circuit; 171-third valve; 18-second heat exchanger; 19-second refrigerant pipeline; 191-sixth valve; 192-seventh valve; 1a-economizer; 1b-gas-liquid separator; 1c-liquid storage tank; 1d-refrigerant radiator. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0026] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Embodiment 1

[0029] like Figure 1As shown, in order to solve the problem of low heating efficiency of domestic water in the existing trigeneration system 1 during winter heating, the trigeneration system 1 of the present invention includes: a compressor 11, which is connected to the refrigerant pipeline and is used for compressing and circulating the refrigerant. The exhaust end of the compressor 11 is connected to a four-way valve 131, and the connection mode of the D, E, S, and C ports of the four-way valve 131 is related to whether it is powered on. When cooling, the four-way valve 131 is powered off, the D port is connected to the C port, and the E port is connected to the S port; when heating, the four-way valve 131 is powered on, the D port is connected to the E port, and the C port is connected to the S port; the water circuit includes a first water circuit 12, the first water circuit 12 is connected to a water source, the first water circuit 12 includes a first sub-water circuit 121, and the first sub-water circuit 121 is provided with a first valve 1213, and the first valve 1213 is communicatively connected to the controller of the trigeneration system 1; the refrigerant pipeline includes a first refrigerant pipeline 13; the first heat exchanger 14 is connected to the exhaust end of the compressor 11 through the first refrigerant pipeline 13, and is also connected to the first sub-water circuit 121, for realizing heat exchange between the refrigerant and water, and the first valve 1213 is arranged between the water source and the first heat exchanger 14; the evaporator 1 5, connected with the first heat exchanger 14 and the air inlet end of the compressor 11 through the first refrigerant pipeline 13, for evaporation of the refrigerant; water tank 16, the first sub-water channel 121 is divided into a first branch water channel 1211 and a second branch water channel 1212 after passing through the first heat exchanger 14, the first branch water channel 1211 is connected with the first water inlet 162 of the water tank 16, for injecting water after heat exchange by the first heat exchanger 14 into the water tank 16, the second branch water channel 1212 is connected with the terminal heat dissipation device, for dissipating heat to the room, an eighth valve 1214 is arranged between the first heat exchanger 14 and the terminal heat dissipation device, the eighth valve 1214 is communicatively connected with the controller of the trigeneration system 1, and the water tank 16 also includes a water outlet 161 for providing domestic water. The water tank 16 also includes a second water inlet 163, and the corresponding water circuit also includes a second water circuit 17. The second water circuit 17 is connected to the water source and the second water inlet 163 of the water tank 16. A second valve 12111 is provided on the first branch water circuit 1211, and a third valve 171 is provided on the second water circuit 17. The second valve 12111 and the third valve 171 are both communicatively connected to the controller of the trigeneration system 1, and the water temperature in the water tank 16 can be adjusted by controlling the opening and closing of the first valve 1213, the second valve 12111 and the third valve 171.

[0030] The first water circuit 12 also includes a second sub-water circuit 122, the trigeneration system 1 also includes a second heat exchanger 18, and the refrigerant pipeline also includes a second refrigerant pipeline 19. The two ends of the second heat exchanger 18 are respectively connected to the exhaust end and the intake end of the compressor 11 through the second refrigerant pipeline 19, and the second heat exchanger 18 is also connected to the second sub-water circuit 122, which is used to realize the heat exchange between the refrigerant and the water. The second sub-water circuit 122 is connected to the third water inlet 164 of the water tank 16 after passing through the second heat exchanger 18. The second sub-water circuit 122 is provided with a fourth valve 1221 and a fifth valve 1222, and the fourth valve 1221 is arranged between the water source and the second heat exchanger 18, the fifth valve 1222 is arranged between the second heat exchanger 18 and the third water inlet 164 of the water tank 16, the second refrigerant pipeline 19 is provided with a sixth valve 191 and a seventh valve 192, the sixth valve 191 is arranged between the exhaust end of the compressor 11 and the second heat exchanger 18, the seventh valve 192 is arranged between the second heat exchanger 18 and the intake end of the compressor 11, and the fourth valve 1221, the fifth valve 1222, the sixth valve 191 and the seventh valve 192 are all communicatively connected with the controller of the trigeneration system 1.

[0031] In the case of adopting the above-mentioned embodiment, when the trigeneration system 1 is required to provide heating and hot water at the same time, the first valve 1213, the second valve 12111, the third valve 171 and the eighth valve 1214 are controlled to be opened, the fourth valve 1221, the fifth valve 1222, the sixth valve 191 and the seventh valve 192 are closed, and the other valves are freely controlled. The working principle at this time is: the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 11 enters the first heat exchanger 14 through the D and E ports of the four-way valve 131, and is changed from a high-temperature and high-pressure gaseous refrigerant to a high-pressure and medium-temperature gas-liquid mixed refrigerant. At this time, the electronic expansion valve PMV3 is fully open. The high-pressure and medium-temperature gas-liquid mixed refrigerant passes through the economizer 1a, the liquid storage tank 1c and the refrigerant radiator 1d and enters the copper tube at the bottom of the condenser, and then is throttled and reduced in pressure by the electronic expansion valve PMV1 to become a low-temperature and low-pressure liquid refrigerant, and then evaporates and absorbs heat in the condenser to become a low-temperature and low-pressure gaseous refrigerant, and then enters the gas-liquid separator 1b through the C and S ports of the four-way valve 131, and then enters the compressor 11 through the suction pipe, forming a refrigerant cycle. The water enters the first heat exchanger 14 from the water inlet through the water pump, the expansion tank and the first valve 1213 to exchange heat with the high-temperature and high-pressure gaseous refrigerant. The heated water flows along the first sub-water channel 121 and is divided into two parts. One part enters the water tank 16 along the first branch water channel 1211 to provide domestic water for users, and the other part flows along the second branch water channel 1212 to the terminal heat dissipation equipment to heat the user's indoor space. Therefore, the trigeneration system 1 of the present invention can achieve rapid heating of water while heating the indoor space, solving the problem of low heating efficiency of domestic water in the existing trigeneration system 1 during winter heating.

[0032] In addition, in order to further enhance the user experience, a second water inlet 163 is provided on the water tank 16 in the present embodiment, and cold water is delivered to the water tank 16 through the second water path 17 and a third valve 171 provided on the second water path 17, thereby adjusting the temperature of the water in the water tank 16 to better meet the user's water needs.

[0033] On the other hand, the above mentioned solution when the trigeneration system 1 is required to provide heating and hot water at the same time, this embodiment also includes a solution when the trigeneration system 1 is required to provide cooling and hot water, specifically, the first valve 1213, the third valve 171, the fourth valve 1221, the fifth valve 1222, the sixth valve 191, the seventh valve 192 and the eighth valve 1214 are controlled to be open, preferably, the seventh valve 192 is a one-way valve, and the flow direction of the one-way valve is toward the direction of the first heat exchanger 14. The following description takes the one-way valve as an example As described above, the second valve 12111 is controlled to be closed. The working principle at this time is as follows: the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 11 is divided into two paths from the four-way valve 131C port. One path passes through the condenser (i.e., the evaporator 15 during heating), the refrigerant radiator 1d, the liquid storage tank 1c, the economizer 1a, and the first heat exchanger 14 to reach the four-way valve 131E port; the other path passes through the second heat exchanger 18 and the water system, and then passes through the electronic expansion valve PMV4 to throttle and reduce the pressure to form a low-temperature and low-pressure gas-liquid mixed state, and then passes through the one-way valve to reach the four-way valve 131E port. After the two paths merge, they enter the gas-liquid separator 1b through the E port and the S port, and then enter the compressor 11 through the suction pipe to form a refrigerant cycle. The water path is divided into two paths from the water inlet through the water pump and the expansion tank. One path enters the first heat exchanger 14 through the first valve 1213 to exchange heat with the low-temperature and low-pressure liquid refrigerant for air conditioning; the other path enters the second heat exchanger 18 through the fourth valve 1221 to exchange heat with the high-temperature and high-pressure gaseous refrigerant and then enters the water tank 16 through the fifth valve 1222 for supplying domestic hot water, thereby achieving rapid heating of water while cooling.

[0034] Embodiment 2

[0035] The present invention also provides a control method for a trigeneration system, wherein the trigeneration system is the trigeneration system mentioned in the first embodiment. Figure 2 , Figure 3 As shown, the control method includes:

[0036] S1. Obtaining control instructions for the trigeneration system;

[0037] S2. Based on the acquired control instructions, the valves are controlled to determine whether the trigeneration system is cooling, heating, and supplying hot water.

[0038] In the above steps, step S2 further comprises:

[0039] S21. If the trigeneration system is required to provide heating and hot water, the fourth valve, the fifth valve, the sixth valve and the seventh valve are controlled to be closed, and the first valve, the second valve, the third valve and the eighth valve are controlled to be opened;

[0040] S22, if the trigeneration system is required to provide heating but not hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve are controlled to be closed, and the first valve and the eighth valve are controlled to be opened;

[0041] S23, if the trigeneration system is required to cool and supply hot water, the first valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve and the eighth valve are controlled to be opened, and the second valve is controlled to be closed;

[0042] S24. If the trigeneration system is required to cool but not supply hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, and the seventh valve are controlled to be closed, and the first valve and the eighth valve are controlled to be opened.

[0043] In the case of adopting the above implementation mode, the heating situation is first introduced. If the trigeneration system is required to provide heating and hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve are controlled to be closed, the first valve and the eighth valve are controlled to be opened, and the other valves are freely controlled. The working principle at this time is: the high-temperature and high-pressure gaseous refrigerant discharged by the compressor enters the first heat exchanger through the D port and the E port of the four-way valve, and the high-temperature and high-pressure gaseous refrigerant is changed into a high-pressure medium-temperature gas-liquid mixed refrigerant. At this time, the electronic expansion valve PMV3 is fully opened. The high-pressure medium-temperature gas-liquid mixed refrigerant enters the copper tube at the bottom of the condenser after passing through the economizer, the liquid storage tank and the refrigerant radiator, and then throttles and reduces the pressure through the electronic expansion valve PMV1 to become a low-temperature and low-pressure liquid refrigerant, evaporates and absorbs heat through the condenser to become a low-temperature and low-pressure gaseous refrigerant, and then enters the gas-liquid separator through the C port and the S port of the four-way valve, and then enters the compressor through the suction pipe to form a refrigerant cycle. The water enters the first heat exchanger from the water inlet through the water pump, the expansion tank and the first valve to exchange heat with the high-temperature and high-pressure gaseous refrigerant. The heated water flows along the first sub-water path and is divided into two parts. One part enters the water tank along the first branch water path to provide domestic water for users, and the other part flows along the second branch water path to the terminal heat dissipation equipment to provide indoor heating for users.

[0044] If the trigeneration system is needed for heating but not for hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve are controlled to be closed, the first valve and the eighth valve are controlled to be open, and the other valves are freely controlled. Compared with the scheme of heating and supplying hot water at the same time, this scheme closes the second valve and the third valve on this basis, so that the water in the water channel only flows along the second branch water channel of the first sub-water channel to the terminal heat dissipation device, thereby providing indoor heating for the user and improving the efficiency of indoor heating.

[0045] The heating situation of the trigeneration system has been introduced above, and the scheme for cooling is introduced next. If the trigeneration system needs to cool and supply hot water, the first valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve and the eighth valve are controlled to be open, the second valve is controlled to be closed, and the other valves are freely controlled. The working principle at this time is: the high-temperature and high-pressure gaseous refrigerant discharged by the compressor comes out from the C port of the four-way valve and is divided into two paths. One path passes through the condenser, the refrigerant radiator, the liquid storage tank, the economizer, and the first heat exchanger to reach the E port of the four-way valve; the other path exchanges heat with the water system through the second heat exchanger, and then passes through the electronic expansion valve PMV4 to throttle and reduce the pressure to form a low-temperature and low-pressure gas-liquid mixed state, and then passes through the one-way valve to reach the E port of the four-way valve. After the two paths merge, they enter the gas-liquid separator through the E port and the S port, and then enter the compressor through the suction pipe to form a refrigerant cycle. The water path is divided into two paths from the water inlet through the water pump and expansion tank. One path enters the first heat exchanger through BV1 to exchange heat with the low-temperature and low-pressure liquid refrigerant for air conditioning refrigeration; the other path enters the second heat exchanger through BV2 to exchange heat with the high-temperature and high-pressure gaseous refrigerant and then enters the water tank through BV4 for supplying domestic hot water. Thus, by dividing the water in the water path into two parts, one part is used for air conditioning refrigeration, and the other part is used for heat exchange with the second heat exchanger for heating, which conveniently and quickly meets the user's needs for refrigeration and hot water supply.

[0046] If the trigeneration system is required for cooling but does not supply hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, and the seventh valve are controlled to be closed, the first valve and the eighth valve are controlled to be opened, and the other valves are freely controlled. The working principle at this time is: the high-temperature and high-pressure gaseous refrigerant discharged by the compressor enters the condenser through the D and C ports of the four-way valve, and changes from the high-temperature and high-pressure gaseous refrigerant to a high-pressure medium-temperature gas-liquid mixed refrigerant. At this time, the electronic expansion valve PMV1 is fully opened. The high-pressure medium-temperature gas-liquid mixed refrigerant enters the economizer for supercooling after passing through the refrigerant radiator and the liquid storage tank, and then throttles and reduces the pressure through the electronic expansion valve PMV3 to become a low-temperature and low-pressure liquid refrigerant. After evaporation and heat absorption through the first heat exchanger, it becomes a low-temperature and low-pressure gaseous refrigerant, and then enters the gas-liquid separator through the E and S ports of the four-way valve, and then enters the compressor through the suction pipe to form a refrigerant cycle. The water enters the first heat exchanger from the water inlet through the water pump, the expansion tank and BV1 to exchange heat with the low-temperature and low-pressure liquid refrigerant, which is used for air conditioning refrigeration, improving the efficiency of indoor refrigeration.

[0047] Embodiment 3

[0048] The speed of heating up the domestic hot water supply is mainly related to the operating frequency of the compressor, and there is a relationship between the operating frequency of the compressor and the set temperature T2 of the water tank and the outlet water temperature T1 of the first heat exchanger or the second heat exchanger. Therefore, in addition to the above two embodiments, the trigeneration system of the present invention also includes a temperature sensor, which is used to obtain the outlet water temperature of the first heat exchanger and the second heat exchanger. The temperature sensor is communicatively connected to the controller of the trigeneration system, such as Figure 4 , Figure 5 As shown, the control method also includes:

[0049] S3, controlling the temperature sensor to obtain the outlet water temperature T2 of the first heat exchanger or the second heat exchanger;

[0050] S4, obtaining the set temperature T1 of the water tank;

[0051] S5, calculating the difference A between T1 and T2;

[0052] S6, comparing the difference A between T1 and T2 with the first preset difference B and the second preset difference C;

[0053] S7, adjusting the operating frequency of the compressor based on the comparison result;

[0054] S71, if A>B, control the compressor to increase the frequency according to the preset value;

[0055] S72, if A<C, control the compressor to reduce the frequency according to the preset value;

[0056] S73. If C≤A≤B, the compressor frequency remains at the original state.

[0057] In the above steps, after step S5, the following steps are further included:

[0058] S8, comparing the difference A between T1 and T2 with the third preset difference D and the fourth preset difference E;

[0059] S81, if A≥D, control the compressor to restart after the first time;

[0060] S82: If A≤E, the compressor is controlled to stop after the first period of time.

[0061] In the case of adopting the above embodiment, the temperature sensor is first controlled to obtain the outlet water temperature T2 of the first heat exchanger or the second heat exchanger, and the set temperature T1 of the water tank is obtained at the same time, the difference A between T1 and T2 is calculated, and A is compared with the first preset difference B and the second preset difference C, wherein the first preset difference B may be 1°C, and the second preset difference C may be -1°C. If C≤A≤B, it means that the outlet water temperature of the heat exchanger is not much different from the set temperature of the water tank at this time, so there is no need to adjust the operating frequency of the compressor. If A>B, it means that the outlet water temperature of the heat exchanger has not reached the set temperature of the water tank at this time. At this time, the compressor should be controlled to increase the frequency by 3min / time and 5rps at most each time to increase the outlet water temperature of the heat exchanger. If A<C, it means that the outlet water temperature of the heat exchanger exceeds the preset temperature of the water tank at this time. At this time, the compressor should be controlled to reduce the frequency by 3min / time and 5rps at most each time to reduce the outlet water temperature of the heat exchanger, so that the outlet water temperature of the heat exchanger can be consistent with the set temperature of the water tank or within a smaller suitable range nearby.

[0062] In addition, the above is only an exemplary adjustment of the operating frequency of the compressor, and technicians in this field can further improve it. For example, further compare the difference between the outlet water temperature of the heat exchanger and the set temperature of the water tank with the size of B1 or C1, where B1 can be 2°C and C1 can be -2°C. When A>B1 or A<C1, control the compressor to reduce the frequency by 3min / time, with a maximum of 10rps each time, or 3min / time, with a maximum of 10rps each time, or adjust the adjustment data or the preset temperature difference each time to other values. These changes do not exceed the technical principles of the present invention and are therefore included in the protection scope of the present invention.

[0063] In addition, since the temperature of the water in the water tank will drop after the heating stops, in this embodiment, A is also compared with the third preset difference D and the fourth preset difference E, where D can be 3°C, E can be -6°C or other suitable values. If A≥D, it means that the temperature of the water in the water tank has dropped significantly after the compressor stops. If A≥D is still true after 5 minutes of continuous detection, the compressor is controlled to restart to heat the water. On the other hand, if A≤E, it means that the actual outlet water temperature of the heat exchanger is much higher than the set temperature of the water tank. Similarly, after continuous detection for 5 minutes to avoid the influence of data fluctuations, the compressor is controlled to stop and no longer heat the water.

[0064] It should be noted that the above-mentioned implementation mode is only used to illustrate the principle of the present invention and is not intended to limit the scope of protection of the present invention. Without departing from the principle of the present invention, those skilled in the art can adjust the above-mentioned structure so that the present invention can be applied to more specific application scenarios.

[0065] Those skilled in the art can understand that the above trigeneration system also includes some other well-known structures, such as processors, controllers, memories, etc., wherein the memories include but are not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory or registers, etc., and the processors include but are not limited to CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. In order to unnecessarily obscure the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0066] Although the various steps in the above embodiment are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. For example, step S3 and step S4 can be executed in parallel or S4 can be executed first and then S3. These simple changes are within the scope of protection of the present invention.

[0067] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A trigeneration system, characterized in that: The trigeneration system comprises: A compressor, connected to the refrigerant pipeline, for compressing and circulating the refrigerant; A waterway, comprising a first waterway, the first waterway being in communication with a water source, the first waterway comprising a first sub-waterway, the first sub-waterway being provided with a first valve, the first valve being in communication connection with a controller of the trigeneration system; A refrigerant pipeline, including a first refrigerant pipeline; a first heat exchanger, which is connected to the exhaust end of the compressor through the first refrigerant pipeline and is also connected to the first sub-water channel, and is used to realize heat exchange between the refrigerant and water, and the first valve is arranged between the water source and the first heat exchanger; an evaporator, connected to the first heat exchanger and the air inlet end of the compressor through the first refrigerant pipeline, and used for evaporating the refrigerant; A water tank, wherein the first sub-water channel is divided into a first branch water channel and a second branch water channel after passing through the first heat exchanger, the first branch water channel is connected to the first water inlet of the water tank, and is used to inject water after heat exchange by the first heat exchanger into the water tank, the second branch water channel is connected to the terminal heat dissipation device, and is used to dissipate heat indoors, an eighth valve is arranged between the first heat exchanger and the terminal heat dissipation device, and the eighth valve is communicatively connected to the controller of the trigeneration system, and the water tank also includes a water outlet for providing domestic water.

2. The trigeneration system according to claim 1, characterized in that: The water tank also includes a second water inlet, and the corresponding water path also includes a second water path, the second water path is connected to a water source and the second water inlet of the water tank, a second valve is provided on the first branch water path, and a third valve is provided on the second water path, the second valve and the third valve are both communicatively connected to the controller of the trigeneration system, and the water temperature in the water tank can be adjusted by controlling the opening and closing of the first valve, the second valve and the third valve.

3. The trigeneration system according to claim 2, characterized in that: The first water circuit also includes a second sub-water circuit, the trigeneration system also includes a second heat exchanger, and the refrigerant pipeline also includes a second refrigerant pipeline. The two ends of the second heat exchanger are respectively connected to the exhaust end and the intake end of the compressor through the second refrigerant pipeline, and the second heat exchanger is also connected to the second sub-water circuit for realizing heat exchange between the refrigerant and water. The second sub-water circuit is connected to the third water inlet of the water tank after passing through the second heat exchanger. A fourth valve and a fifth valve are arranged on the second sub-water circuit. The fourth valve is arranged between the water source and the second heat exchanger, and the fifth valve is arranged between the second heat exchanger and the third water inlet of the water tank. A sixth valve and a seventh valve are arranged on the second refrigerant pipeline. The sixth valve is arranged between the exhaust end of the compressor and the second heat exchanger, and the seventh valve is arranged between the second heat exchanger and the intake end of the compressor. The fourth valve, the fifth valve, the sixth valve and the seventh valve are all communicatively connected to the controller of the trigeneration system.

4. A control method for a trigeneration system, characterized in that: The trigeneration system is the trigeneration system described in claim 3, and the control method comprises: Obtaining control instructions for the trigeneration system; Based on the acquired control instructions, the valves are controlled according to whether the trigeneration system is cooling, heating and supplying hot water.

5. The control method of the trigeneration system according to claim 4, characterized in that: The step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating and supplying hot water" further includes: If the trigeneration system is required to provide heating and hot water, the fourth valve, the fifth valve, the sixth valve and the seventh valve are controlled to be closed, and the first valve, the second valve, the third valve and the eighth valve are controlled to be opened.

6. The control method of the trigeneration system according to claim 4, characterized in that: The step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating and supplying hot water" further includes: If the trigeneration system is required to provide heating but not hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve are controlled to be closed, and the first valve and the eighth valve are controlled to be opened.

7. The control method of the trigeneration system according to claim 4, characterized in that: The step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating and supplying hot water" further includes: If the trigeneration system is required to cool and supply hot water, the first valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve and the eighth valve are controlled to open, and the second valve is controlled to close.

8. The control method of the trigeneration system according to claim 4, characterized in that: The step of "controlling the valve based on the acquired control instruction as to whether the trigeneration system is cooling, heating and supplying hot water" further includes: If the trigeneration system is required to cool but not supply hot water, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, and the seventh valve are controlled to be closed, and the first valve and the eighth valve are controlled to be opened.

9. The control method of the trigeneration system according to claim 4, characterized in that: The trigeneration system further includes a temperature sensor, which is used to obtain the outlet water temperature of the first heat exchanger and the second heat exchanger, and the temperature sensor is communicatively connected to the controller of the trigeneration system. The control method further includes: Controlling the temperature sensor to obtain the outlet water temperature T2 of the first heat exchanger or the second heat exchanger; Obtaining the set temperature T1 of the water tank; Calculate the difference A between T1 and T2; Compare the difference A between T1 and T2 with the first preset difference B and the second preset difference C; adjusting the operating frequency of the compressor based on the comparison result; If A>B, the compressor is controlled to increase frequency according to a preset value; If A<C, the compressor is controlled to reduce frequency according to a preset value; If C≤A≤B, the compressor frequency remains the same.

10. The control method of the trigeneration system according to claim 9, characterized in that: The step of "calculating the difference A between T1 and T2" also includes: Compare the difference A between T1 and T2 with the third preset difference D and the fourth preset difference E; If A≥D, controlling the compressor to restart after a first period of time; If A≤E, the compressor is controlled to stop after a first period of time.

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