Direct-fired lithium bromide absorption heat pump unit with load balancing heat exchanger

Abstract

The present invention relates to a direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger, comprising an absorber, a refrigerant pump, a solution pump, an evaporator, a solution heat exchanger, a direct-fired generator, a condenser and a hot water heat exchanger, wherein the hot water heat exchanger is used as a load balancing heat exchanger, and a hot water electric three-way regulating valve is arranged on the waste hot water inlet pipe of the unit. When the waste hot water inlet temperature or waste hot water flow rate of the unit is lower than the design parameter, a part or all of the waste hot water is used to exchange heat with hot water through the load balancing heat exchanger, so as to increase the waste hot water inlet temperature of the evaporator, and at the same time increase the fuel combustion amount, so as to achieve a balance between the heat supply and the evaporator load, so that the unit can operate at full load and meet the heating demand.

Description

Technical Field

[0001] The invention relates to the technical field of air conditioning equipment, and in particular to a direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger. Background Art

[0002] A conventional direct-fired single-effect lithium bromide absorption heat pump unit is Figure 1 As shown, the unit is composed of an evaporator 4, an absorber 1, a direct-fired generator 7, a condenser 8, a solution heat exchanger 5, a solution pump 3, a refrigerant pump 2, a control system (not shown in the figure) and pipes and valves connecting the various components. When the unit is running, the heat generated by the burner 6 of the direct-fired generator 7 burning fuel (gas, oil) is used as compensation heat energy to recover the heat of the waste heat source hot water entering and leaving the evaporator 4, and provide hot water for process or building heating with a temperature higher than the temperature of the waste heat source hot water. It is mainly used in places with both low-temperature heat sources and medium-temperature heating needs. There is a relatively stable proportional relationship between the heat supply of this unit and the evaporator load (i.e., the heat supply of waste hot water). The heat supply is generally 2.15~2.35 times the heat supply of waste hot water. When the heat supply of waste hot water decreases due to the decrease in the inlet temperature of waste hot water or the decrease in the flow rate of waste hot water, the heat supply of the unit will decrease accordingly. The lower the inlet temperature of waste hot water or the smaller the flow rate of waste hot water, the smaller the heat supply, making it difficult to operate at full load and meet the heating demand. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings. By adding a load balancing heat exchanger and a hot water electric three-way regulating valve on the basis of the previous direct-fired single-effect lithium bromide absorption heat pump unit, when the waste hot water inlet temperature or waste hot water flow rate of the unit is lower than the design parameters, a part or all of the waste hot water is heat exchanged with hot water through the load balancing heat exchanger, the waste hot water inlet temperature of the evaporator is increased, and at the same time, the fuel combustion amount is increased to achieve a balance between the heat supply and the evaporator load, so that the unit can operate at full load and meet the heating demand.

[0004] The object of the present invention is achieved in that:

[0005] A direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger comprises an absorber, a refrigerant pump, a solution pump, an evaporator, a solution heat exchanger, a direct-fired generator and a condenser. It also comprises a hot water heat exchanger, which is used as a load balancing heat exchanger. A hot water electric three-way regulating valve is arranged on the waste hot water inlet pipe of the unit.

[0006] Preferably, the hot water electric three-way regulating valve is a diversion type hot water electric three-way regulating valve, the inlet of the hot water electric three-way regulating valve is connected to the waste hot water inlet pipe of the unit, the straight outlet of the hot water electric three-way regulating valve is connected to the water inlet pipe of the evaporator, the bypass outlet of the hot water electric three-way regulating valve is connected to the low-temperature water inlet pipe of the hot water heat exchanger, and the low-temperature water outlet pipe of the hot water heat exchanger is connected to the water inlet pipe of the evaporator.

[0007] Preferably, the hot water electric three-way regulating valve is a converging type hot water electric three-way regulating valve, the straight inlet of the hot water electric three-way regulating valve is connected to the waste hot water inlet pipe of the unit, the bypass inlet of the hot water electric three-way regulating valve is connected to the low-temperature water outlet pipe of the hot water heat exchanger, the outlet of the hot water electric three-way regulating valve is connected to the water inlet pipe of the evaporator, and the low-temperature water inlet pipe of the hot water heat exchanger is connected to the waste hot water inlet pipe of the unit.

[0008] Preferably, the outlet pipe of the absorber is connected to the hot water heat exchanger as the high-temperature water inlet pipe of the hot water heat exchanger, and the high-temperature water outlet pipe of the hot water heat exchanger is connected to the condenser as the water inlet pipe of the condenser.

[0009] Preferably, when the waste hot water inlet temperature or waste hot water flow rate of the unit is lower than the design parameters, part or all of the waste hot water is used to exchange heat with hot water through a hot water heat exchanger to increase the waste hot water inlet temperature of the evaporator, while increasing the fuel combustion amount to match the heat supply with the evaporator load.

[0010] The beneficial effects of the present invention are:

[0011] The unit of the present invention is provided with a load balancing heat exchanger and a hot water electric three-way regulating valve. When the waste hot water inlet temperature or the waste hot water flow rate of the unit is lower than the design parameters, a part or all of the waste hot water is used to exchange heat with hot water through the load balancing heat exchanger, thereby increasing the waste hot water inlet temperature of the evaporator and increasing the fuel combustion amount at the same time, achieving a balance between the heat supply and the evaporator load, so that the unit can operate at full load and meet the heating demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of a previous direct-fired single-effect lithium bromide absorption heat pump unit.

[0013] Figure 2 This is a schematic structural diagram of a direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger according to the first embodiment of the present invention.

[0014] Figure 3 Schematic diagram of the structure of a direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger according to the second embodiment of the present invention.

[0015] Figure 4Schematic diagram of the structure of a direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger according to the third embodiment of the present invention.

[0016] Among them: 1-absorber, 2-refrigerant pump, 3-solution pump, 4-evaporator, 5-solution heat exchanger, 6-burner, 7-direct-fired generator, 8-condenser, 9-hot water outlet pipe, 10-absorber outlet pipe, 11-waste hot water outlet pipe, 12-evaporator inlet pipe, 13-hot water electric three-way regulating valve, 14-waste hot water inlet pipe, 15-hot water heat exchanger low-temperature water outlet pipe, 16-hot water heat exchanger low-temperature water inlet pipe, 17-hot water heat exchanger, 18-hot water inlet pipe, 19-absorber inlet pipe, 20-condenser inlet pipe. DETAILED DESCRIPTION

[0017] The first implementation method is shown in Figure 2 The present invention relates to a direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger, which is composed of an evaporator 4, an absorber 1, a direct-fired generator 7, a condenser 8, a solution heat exchanger 5, a hot water heat exchanger 17, a solution pump 3, a refrigerant pump 2, a control system (not shown in the figure), and pipes and valves connecting the various components. The hot water heat exchanger 17 is used as a load balancing heat exchanger, and the high-temperature side of the hot water heat exchanger 17 carries hot water, and the low-temperature side carries waste hot water. A diversion type hot water electric three-way regulating valve 13 is arranged on the waste hot water inlet pipe 14 of the unit, the inlet of the hot water electric three-way regulating valve 13 is connected to the waste hot water inlet pipe 14 of the unit, the straight outlet of the hot water electric three-way regulating valve 13 is connected to the evaporator water inlet pipe 12, the bypass outlet of the hot water electric three-way regulating valve 13 is connected to the low-temperature water inlet pipe 16 of the hot water heat exchanger, and the low-temperature water outlet pipe 15 of the hot water heat exchanger is connected to the evaporator water inlet pipe 12; the high-temperature water inlet pipe of the hot water heat exchanger 17 is the hot water inlet pipe 18 of the unit, and the high-temperature water outlet pipe of the hot water heat exchanger 17 is connected to the absorber 1 as the absorber water inlet pipe 19.

[0018] When the unit is running, the opening, closing and opening degree of the bypass outlet side of the hot water electric three-way regulating valve 13 are automatically regulated and controlled by the control system of the unit according to the waste hot water outlet temperature and the hot water outlet temperature: if the waste hot water outlet temperature is greater than or equal to the design temperature, the hot water outlet temperature can reach the design temperature, the bypass outlet side of the hot water electric three-way regulating valve 13 is closed, and the waste hot water does not enter the hot water heat exchanger 17; if the waste hot water outlet temperature has dropped to the design temperature but the hot water outlet temperature has not reached the design temperature, the bypass outlet side of the hot water electric three-way regulating valve 13 is opened, and a part of the waste hot water enters the hot water heat exchanger 17 through the low-temperature water inlet pipe 16 of the hot water heat exchanger, exchanges heat with the hot water flowing through the hot water heat exchanger 17 to increase the temperature, and then exits the hot water heat exchanger 17 through the low-temperature water outlet pipe 15 of the hot water heat exchanger, merges with the rest of the waste hot water, and enters the evaporator 4 through the evaporator water inlet pipe 12, thereby increasing the waste hot water inlet temperature of the evaporator 4, increasing the evaporator load, and achieving a balance between the heat supply and the evaporator load, so that the unit can operate at full load and meet the heating demand. The lower the inlet temperature of the waste hot water or the smaller the flow rate, the greater the opening of the bypass outlet side of the hot water electric three-way regulating valve 13 until it is fully opened, and the greater the flow rate of waste hot water flowing through the hot water heat exchanger 17 until all the waste hot water flows through the hot water heat exchanger 17. Under this operating condition, the hot water inlet temperature of the absorber 1 is reduced due to heat exchange between hot water and waste hot water, so that the hot water outlet temperature of the absorber 1 and the hot water inlet temperature of the condenser 8 are reduced accordingly. It is necessary to increase the fuel combustion amount of the burner 6 and increase the heat load of the condenser 8 simultaneously to make the hot water outlet temperature meet the requirements.

[0019] The second implementation method is shown in Figure 3 A converging type hot water electric three-way regulating valve 13 is arranged on the waste hot water inlet pipe 14 of the unit, the straight inlet of the hot water electric three-way regulating valve 13 is connected to the waste hot water inlet pipe 14 of the unit, the bypass inlet of the hot water electric three-way regulating valve 13 is connected to the low-temperature water outlet pipe 15 of the hot water heat exchanger, and the low-temperature water inlet pipe of the hot water heat exchanger 17 - the inlet pipe 16 of the low-temperature water inlet pipe of the hot water heat exchanger is connected to the waste hot water inlet pipe 14. The rest of the structure is the same as that of the first embodiment.

[0020] When the unit is running, the opening, closing and opening degree of the bypass inlet side of the hot water electric three-way regulating valve 13 are automatically adjusted and controlled by the control system of the unit according to the waste hot water outlet temperature and the hot water outlet temperature, so as to adjust and control the waste hot water flow through the hot water heat exchanger 17, and the adjustment and control method is the same as the first implementation mode.

[0021] The third embodiment is shown in Figure 4 The absorber outlet pipe 10 is connected to the hot water heat exchanger 17 as the high-temperature water inlet pipe of the hot water heat exchanger, and the high-temperature water outlet pipe of the hot water heat exchanger 17 is connected to the condenser as the condenser inlet pipe 20. The rest of the structure is the same as that of the first embodiment.

[0022] When the unit is running, the opening, closing and opening degree of the bypass outlet side of the hot water electric three-way regulating valve 13 are automatically adjusted and controlled by the control system of the unit according to the waste hot water outlet temperature and the hot water outlet temperature, so as to adjust and control the waste hot water flow through the hot water heat exchanger 17, and the adjustment and control method is the same as the first implementation mode.

[0023] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. A direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger, comprising an absorber (1), a refrigerant pump (2), a solution pump (3), an evaporator (4), a solution heat exchanger (5), a direct-fired generator (7) and a condenser (8), characterized in that: It also includes a hot water heat exchanger (17), which is used as a load balancing heat exchanger. A hot water electric three-way regulating valve (13) is provided on the waste hot water inlet pipe (14) of the unit. The hot water electric three-way regulating valve (13) is a diversion type hot water electric three-way regulating valve, the inlet of the hot water electric three-way regulating valve (13) is connected to the waste hot water inlet pipe (14) of the unit, the straight outlet of the hot water electric three-way regulating valve (13) is connected to the water inlet pipe of the evaporator (4) - the evaporator water inlet pipe (12), the bypass outlet of the hot water electric three-way regulating valve (13) is connected to the low-temperature water inlet pipe of the hot water heat exchanger (17) - the hot water heat exchanger low-temperature water inlet pipe (16), and the low-temperature water outlet pipe of the hot water heat exchanger (17) - the hot water heat exchanger low-temperature water outlet pipe (15) is connected to the water inlet pipe of the evaporator (4) - the evaporator water inlet pipe (12); Alternatively, the hot water electric three-way regulating valve (13) is a confluence type hot water electric three-way regulating valve, the direct inlet of the hot water electric three-way regulating valve (13) is connected to the waste hot water inlet pipe (14) of the unit, the bypass inlet of the hot water electric three-way regulating valve (13) is connected to the low-temperature water outlet pipe of the hot water heat exchanger (17) - the low-temperature water outlet pipe (15) of the hot water heat exchanger, the outlet of the hot water electric three-way regulating valve (13) is connected to the water inlet pipe of the evaporator (4) - the evaporator water inlet pipe (12), and the low-temperature water inlet pipe of the hot water heat exchanger (17) - the low-temperature water inlet pipe (16) of the hot water heat exchanger is connected to the waste hot water inlet pipe (14) of the unit; Alternatively, the water outlet pipe of the absorber (1) - the absorber water outlet pipe (10) is connected to the hot water heat exchanger (17) as the high-temperature water inlet pipe of the hot water heat exchanger (17), and the high-temperature water outlet pipe of the hot water heat exchanger (17) is connected to the condenser (8) as the water inlet pipe of the condenser (8) - the condenser water inlet pipe (20).

2. A direct-fired lithium bromide absorption heat pump unit with a load balancing heat exchanger according to claim 1, characterized in that: When the waste hot water inlet temperature or waste hot water flow rate of the unit is lower than the design parameters, part or all of the waste hot water is used to exchange heat with hot water through the hot water heat exchanger to increase the waste hot water inlet temperature of the evaporator, while increasing the fuel combustion amount to match the heat supply with the evaporator load.

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