Low-environment-temperature efficient heat pump system capable of uninterruptedly operating during defrosting

Abstract

The invention discloses a defrosting uninterrupted operation low-environment-temperature efficient heat pump system which comprises a heat pump heating system, a defrosting system and a heat storage system. The double-evaporator design is adopted, and the functions of single-evaporator and double-evaporator switching, system defrosting and the like can be achieved through switching of a three-way valve and starting and stopping of a water pump. The evaporators adopt water tank hot water to defrost separately, and when one evaporator of the system defrosts, the other evaporator operates normally, so that normal operation of the defrosting system is realized; the system adopts a double-evaporator parallel structure, single evaporators operate at intervals when the environment temperature is higher, and double evaporators work simultaneously when the environment temperature is lower, so that the overall heating capacity of the low-environment-temperature system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of heat pump systems, in particular to a low ambient temperature and high efficiency heat pump system with uninterrupted defrosting operation. Background Art

[0002] The heat pump system includes an evaporator, a compressor and a condenser connected by pipes. The heat pump is an efficient and energy-saving device that fully utilizes low-grade thermal energy. The working principle of the heat pump is a mechanical device that forces heat from a low-temperature object to a high-temperature object in a reverse cycle. It consumes only a small amount of reverse cycle net work to obtain a large amount of heat supply, and can effectively utilize the difficult-to-use low-grade thermal energy to achieve energy saving. In the prior art, the existing heat pump systems in China generally need to stop the main unit when defrosting, and the energy efficiency is generally low when operating in a low-temperature environment. Summary of the invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies in the prior art and propose a low ambient temperature high efficiency heat pump system with uninterrupted defrosting operation that improves the energy efficiency of the system operation.

[0004] The technical problem to be solved by the present invention is achieved through the following technical solution: a low ambient temperature and high efficiency heat pump system with uninterrupted defrosting operation, which is characterized by: It includes a first circulation system, a second circulation system, a third circulation system and a heat exchanger; the first circulation system is a heat pump heating system, the second circulation system is a defrosting system, and the third circulation system is a heat storage system; The first circulation system includes an evaporator, a compressor, a heat exchanger, an electronic expansion valve, and a compression pipeline and an expansion pipeline; the compressor is installed on the compression pipeline, and the electronic expansion valve is installed on the expansion pipeline; The third circulation system includes a heat exchanger, a hot water storage tank, a three-system circulation pump and a three-system circulation pipeline; The second circulation system includes an evaporator, a second system circulation pump, a hot water storage tank, and a defrost water inlet pipe and a defrost water return pipe. The first circulation system and the second circulation system share the same set of evaporators; the third circulation system and the second circulation system share the same hot water storage tank; the heat exchanger in the first circulation system and the heat exchanger in the third circulation system are the same heat exchanger, wherein the compression pipeline and expansion pipeline heat exchanger of the first circulation system are connected to the heating side of the heat exchanger, and the three-system circulation pipeline of the third circulation system are connected to the heat exchange side of the above heat exchanger; The evaporator is an evaporator I and an evaporator II arranged in parallel. The heating ends of the evaporators I and II are connected in parallel and connected to the compression pipeline. A regulating valve group is arranged between the return ends of the evaporators I and II and the expansion pipeline. The defrost inlet of evaporator I and evaporator II is connected to the defrost water inlet pipe through a defrost three-way reversing valve, and the defrost outlet of evaporator I and evaporator II is connected to the defrost water return pipe; evaporator I and evaporator II are defrosted at intervals to maintain the normal operation of the system; The regulating valve group includes at least four three-way reversing valves, the first three-way reversing valve is connected to the reflux end of evaporator I, the second three-way reversing valve is connected to the reflux end of evaporator II, the third three-way reversing valve is connected between the first and second three-way reversing valves, the fourth three-way reversing valve is connected between the first and third three-way reversing valves, and one of the ports of the fourth and second three-way reversing valves is connected to the expansion pipeline; the conversion between the interval operation state and the simultaneous working state of the two evaporators is realized by switching between the three-way reversing valves in the above-mentioned regulating valve group.

[0005] The technical problem to be solved by the present invention can be further achieved by the following technical solution: a start-stop solenoid valve is installed on the defrost water inlet pipe.

[0006] Compared with the prior art, the present invention adopts a dual evaporator design. The evaporators are defrosted at intervals using hot water from a water tank. When one evaporator in the system is defrosting, the other evaporator operates normally, thereby realizing normal operation of the defrost system. The system adopts a dual evaporator parallel structure. When the ambient temperature is high, the single evaporator operates at intervals. When the ambient temperature is low, the dual evaporators work simultaneously, thereby improving the overall heating capacity of the low ambient temperature system. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is the principle diagram of the system composition of the present invention; Figure 2 This is the operating principle diagram of the low ambient temperature double evaporator; Figure 3 The operating principle of the high ambient temperature single evaporator Figure 1 ; Figure 4 The operating principle of the high ambient temperature single evaporator Figure 2 ; Figure 5 This is the defrosting operation schematic diagram of evaporator 1; Figure 6 This is the defrost operation schematic diagram of evaporator 2.

[0008] in: 1 is the unified evaporator I, 2 is the unified evaporator II, 3 is the compressor, 4 is the second system circulation pump, 5 is the heat exchanger, 6 is the hot water storage tank, 7 is the third system circulation pump, 8 is the electronic expansion valve; 9, 10, 11, 12, 13 are three-way reversing valves, and 14 is the start-stop solenoid valve. DETAILED DESCRIPTION

[0009] The specific technical solutions of the present invention are further described below. To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer and to facilitate those skilled in the art to further understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them, and do not constitute a limitation on the rights thereof. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0010] A low ambient temperature high efficiency heat pump system with uninterrupted defrosting operation comprises a first circulation system, a second circulation system, a third circulation system and a heat exchanger; the first circulation system is a heat pump heating system, the second circulation system is a defrosting system, and the third circulation system is a heat storage system.

[0011] The first circulation system includes an evaporator, a compressor, a heat exchanger, an electronic expansion valve, and a compression pipeline and an expansion pipeline; the compressor is installed on the compression pipeline, and the electronic expansion valve is installed on the expansion pipeline; The third circulation system includes a heat exchanger, a hot water storage tank, a three-system circulation pump and a three-system circulation pipeline; the second circulation system includes an evaporator, a second-system circulation pump, a hot water storage tank, and a defrost water inlet pipe and a defrost water return pipe.

[0012] The first circulation system and the second circulation system share the same set of evaporators; the third circulation system and the second circulation system share the same hot water storage tank; the heat exchanger in the first circulation system and the heat exchanger in the third circulation system are the same heat exchanger, wherein the compression pipeline and expansion pipeline heat exchanger of the first circulation system are connected to the heating side of the heat exchanger, and the three-system circulation pipelines of the third circulation system are connected to the heat exchange side of the above-mentioned heat exchanger.

[0013] The evaporator is an evaporator I and an evaporator II arranged in parallel. The heating ends of the evaporators I and II are connected to the compression pipeline after being connected in parallel. A regulating valve group is arranged between the return ends of the evaporators I and II and the expansion pipeline. The defrost inlets of the evaporators I and II are connected to the defrost water inlet pipe through a defrost three-way reversing valve, and the defrost outlets of the evaporators I and II are connected to the defrost water return pipe; the evaporators I and II are defrosted at intervals to maintain the normal operation of the system.

[0014] The regulating valve group includes at least four three-way reversing valves, the first three-way reversing valve is connected to the reflux end of evaporator I, the second three-way reversing valve is connected to the reflux end of evaporator II, the third three-way reversing valve is connected between the first and second three-way reversing valves, the fourth three-way reversing valve is connected between the first and third three-way reversing valves, and one of the ports of the fourth and second three-way reversing valves is connected to the expansion pipeline; the conversion between the interval operation state and the simultaneous working state of the two evaporators is realized by switching between the three-way reversing valves in the above-mentioned regulating valve group.

[0015] A start-stop solenoid valve is installed on the defrost water inlet pipe.

[0016] The present invention adopts a dual-evaporator structural design, which can realize normal system output while the system is defrosted; a dual-medium evaporator is adopted, and the defrosting heat source is taken to the terminal pressure water tank without affecting the normal operation of the system; a single evaporator is operated at high ambient temperature, and a dual evaporator is operated at low ambient temperature, thereby improving the operating capacity and energy efficiency of the low-temperature system.

[0017] Low temperature operation: Figure 2 As shown, when the ambient temperature is low, the dual evaporators of the system operate. The a and c ends of the three-way reversing valve 9 are connected, the a and c ends of the three-way reversing valve 11 are connected, the a and c ends of the three-way reversing valve 12 are connected, the a and b ends of the solenoid valve 14 are closed, the compressor 3 operates, and the circulating water pump 7 operates. The compressor 3, the evaporator 1, the evaporator 2, the heat exchanger 5, and the electronic expansion valve 8 constitute a primary system. The primary system sends heat to the tertiary system through the heat exchanger 5, and the secondary system (defrosting) does not operate.

[0018] High temperature operation 1: Figure 3 As shown, when the ambient temperature is high, the system operates with a single evaporator. The a and b ends of the three-way reversing valve 9 are connected, the b and c ends of the three-way reversing valve 10 are connected, the a and b ends of the three-way reversing valve 11 are connected, the b and c ends of the three-way reversing valve 12 are connected, the a and b ends of the solenoid valve 14 are closed, the compressor 3 operates, and the circulating water pump 7 operates. The compressor 3, the evaporator 2, the heat exchanger 5, and the electronic expansion valve 8 form a primary system, and the primary system sends heat to the tertiary system through the heat exchanger 5, and the secondary system (defrosting) does not operate.

[0019] High temperature operation 2: Figure 4 As shown, when the ambient temperature is high, the system operates with a single evaporator. The a and b ends of the three-way reversing valve 9 are connected, the a and b ends of the three-way reversing valve 10 are connected, the a and b ends of the three-way reversing valve 11 are connected, the b and c ends of the three-way reversing valve 12 are connected, the a and b ends of the solenoid valve 14 are closed, and the compressor 3 operates. The compressor 3, the evaporator 1, the heat exchanger 5, and the electronic expansion valve 8 form a primary system. The primary system sends heat to the tertiary system through the heat exchanger 5, and the secondary system (defrosting) does not operate. The evaporator 1 and the evaporator 2 are switched on and off according to the balanced loss judgment.

[0020] Evaporator 1 defrosting: Figure 5 As shown, when the system reaches the defrosting condition, evaporator 1 starts the defrosting mode first. The a and b ends of the three-way reversing valve 9 are connected, the b and c ends of the three-way reversing valve 10 are connected, the a and b ends of the three-way reversing valve 11 are connected, the a and c ends of the three-way reversing valve 13 are connected, the a and b ends of the solenoid valve 14 are connected, the compressor 1 is running, and the circulating water pump 4 and the circulating water pump 7 are started. The compressor 3, the evaporator 2, the heat exchanger 5, and the electronic expansion valve 8 form a primary system. The primary system sends heat to the tertiary system through the heat exchanger 5, and the secondary (defrosting) system is running.

[0021] Evaporator 2 defrosting: Figure 6 As shown, when the system reaches the defrosting condition and the evaporator 1 completes the defrosting, the evaporator 2 starts the defrosting mode. The a and b ends of the three-way reversing valve 9 are connected, the a and b ends of the three-way reversing valve 10 are connected, the a and b ends of the three-way reversing valve 11 are connected, the a and b ends of the three-way reversing valve 13 are connected, the a and b ends of the solenoid valve 14 are connected, the compressor 1 is running, and the circulating water pump 4 and the circulating water pump 7 are started. The compressor 3, the evaporator 2, the heat exchanger 5, and the electronic expansion valve 8 form a primary system. The primary system sends heat to the tertiary system through the heat exchanger 5, and the secondary (defrosting) system is running.

Claims

1. A low ambient temperature and high efficiency heat pump system with uninterrupted defrosting operation, characterized by: It includes a first circulation system, a second circulation system, a third circulation system and a heat exchanger; the first circulation system is a heat pump heating system, the second circulation system is a defrosting system, and the third circulation system is a heat storage system; The first circulation system includes an evaporator, a compressor, a heat exchanger, an electronic expansion valve, and a compression pipeline and an expansion pipeline; the compressor is installed on the compression pipeline, and the electronic expansion valve is installed on the expansion pipeline; The third circulation system includes a heat exchanger, a hot water storage tank, a three-system circulation pump and a three-system circulation pipeline; The second circulation system includes an evaporator, a second system circulation pump, a hot water storage tank, and a defrost water inlet pipe and a defrost water return pipe. The first circulation system and the second circulation system share the same set of evaporators; the third circulation system and the second circulation system share the same hot water storage tank; the heat exchanger in the first circulation system and the heat exchanger in the third circulation system are the same heat exchanger, wherein the compression pipeline and expansion pipeline heat exchanger of the first circulation system are connected to the heating side of the heat exchanger, and the three-system circulation pipeline of the third circulation system are connected to the heat exchange side of the above heat exchanger; The evaporator is an evaporator I and an evaporator II arranged in parallel. The heating ends of the evaporators I and II are connected in parallel and connected to the compression pipeline. A regulating valve group is arranged between the return ends of the evaporators I and II and the expansion pipeline. The defrost inlet of evaporator I and evaporator II is connected to the defrost water inlet pipe through a defrost three-way reversing valve, and the defrost outlet of evaporator I and evaporator II is connected to the defrost water return pipe; evaporator I and evaporator II are defrosted at intervals to maintain the normal operation of the system; The regulating valve group includes at least four three-way reversing valves, the first three-way reversing valve is connected to the reflux end of evaporator I, the second three-way reversing valve is connected to the reflux end of evaporator II, the third three-way reversing valve is connected between the first and second three-way reversing valves, the fourth three-way reversing valve is connected between the first and third three-way reversing valves, and one of the ports of the fourth and second three-way reversing valves is connected to the expansion pipeline; the conversion between the interval operation state and the simultaneous working state of the two evaporators is realized by switching between the three-way reversing valves in the above-mentioned regulating valve group.

2. The uninterrupted defrosting low ambient temperature high efficiency heat pump system according to claim 1 is characterized by: A start-stop solenoid valve is installed on the defrost water inlet pipe.

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